Prevalencia de osteopenia del prematuro antes y después de la implementación de una estrategia temprana de manejo fosfocálcico / Prevalence of osteopenia of prematurity before and after implementing an early strategy with the use of calcium and phosphate

Introducción. Con el uso de la nutrición parenteral agresiva en recién nacidos de muy bajo peso, se detectaron alteraciones del metabolismo fosfocálcico. En 2016 se implementó una estrategia de prevención a través del monitoreo fosfocálcico y su suplementación temprana. El objetivo fue estudiar si esta estrategia disminuye la prevalencia de osteopenia e identificar factores de riesgo asociados. Población y métodos. Estudio cuasiexperimental que comparó la prevalencia de osteopenia entre dos grupos: uno después de implementar la estrategia de monitoreo y suplementación fosfocálcica (01/01/2017-31/12/2019), y otro previo a dicha intervención (01/01/2013-31/12/2015). Resultados. Se incluyeron 226 pacientes: 133 pertenecen al período preintervención y 93 al posintervención. La prevalencia de osteopenia global fue del 26,1 % (IC95% 20,5-32,3) y disminuyó del 29,3 % (IC95% 21,7-37,8) en el período preintervención al 21,5 % (IC95% 13,6-31,2) en el posintervención, sin significancia estadística (p = 0,19). En el análisis multivariado, el puntaje NEOCOSUR de riesgo de muerte al nacer, recibir corticoides posnatales y el período de intervención se asociaron de manera independiente a osteopenia. Haber nacido luego de la intervención disminuyó un 71 % la probabilidad de presentar fosfatasa alcalina >500 UI/L independientemente de las restantes variables incluidas en el modelo. Conclusión. La monitorización y suplementación fosfocálcica precoz constituye un factor protector para el desarrollo de osteopenia en recién nacidos con muy bajo peso al nacer.

Introduction. With the use of aggressive parenteral nutrition in very low birth weight infants, alterations in calcium and phosphate metabolism were detected. In 2016, a prevention strategy was implemented through calcium phosphate monitoring and early supplementation. Our objective was to study whether this strategy reduces the prevalence of osteopenia and to identify associated risk factors. Population and methods. Quasi-experiment comparing the prevalence of osteopenia between two groups: one after implementing the calcium phosphate monitoring and supplementation strategy (01/01/2017­12/31/2019) and another prior to such intervention (01/01/2013­12/31/2015). Results. A total of 226 patients were included: 133 in the pre-intervention period and 93 in the post-intervention period. The overall prevalence of osteopenia was 26.1% (95% CI: 20.5­32.3) and it was reduced from 29.3% (95% CI: 21.7­37.8) in the pre-intervention period to 21.5% (95% CI: 13.6­31.2) in the post-intervention period, with no statistical significance (p = 0.19). In the multivariate analysis, the NEOCOSUR score for risk of death at birth, use of postnatal corticosteroids, and the intervention period were independently associated with osteopenia. Being born after the intervention reduced the probability of alkaline phosphatase > 500 IU/L by 71%, regardless of the other variables included in the model. Conclusion. Calcium phosphate monitoring and early supplementation is a protective factor against the development of osteopenia in very low birth weight infants.

Preparation and properties of a new artificial bone composite material / 中国修复重建外科杂志

OBJECTIVE@#To study the preparation and properties of the hyaluronic acid (HA)/α-calcium sulfate hemihydrate (α-CSH)/β-tricalcium phosphate (β-TCP) material (hereinafter referred to as composite material).@*METHODS@#Firstly, the α-CSH was prepared from calcium sulfate dihydrate by hydrothermal method, and the β-TCP was prepared by wet reaction of soluble calcium salt and phosphate. Secondly, the α-CSH and β-TCP were mixed in different proportions (10∶0, 9∶1, 8∶2, 7∶3, 5∶5, and 3∶7), and then mixed with HA solutions with concentrations of 0.1%, 0.25%, 0.5%, 1.0%, and 2.0%, respectively, at a liquid-solid ratio of 0.30 and 0.35 respectively to prepare HA/α-CSH/ β-TCP composite material. The α-CSH/β-TCP composite material prepared with α-CSH, β-TCP, and deionized water was used as the control. The composite material was analyzed by scanning electron microscope, X-ray diffraction analysis, initial/final setting time, degradation, compressive strength, dispersion, injectability, and cytotoxicity.@*RESULTS@#The HA/α-CSH/β-TCP composite material was prepared successfully. The composite material has rough surface, densely packed irregular block particles and strip particles, and microporous structures, with the pore size mainly between 5 and 15 μm. When the content of β-TCP increased, the initial/final setting time of composite material increased, the degradation rate decreased, and the compressive strength showed a trend of first increasing and then weakening; there were significant differences between the composite materials with different α-CSH/β-TCP proportion ( P<0.05). Adding HA improved the injectable property of the composite material, and it showed an increasing trend with the increase of concentration ( P<0.05), but it has no obvious effect on the setting time of composite material ( P>0.05). The cytotoxicity level of HA/α-CSH/β-TCP composite material ranged from 0 to 1, without cytotoxicity.@*CONCLUSION@#The HA/α-CSH/β-TCP composite materials have good biocompatibility. Theoretically, it can meet the clinical needs of bone defect repairing, and may be a new artificial bone material with potential clinical application prospect.

Dental impact of anti-fibroblast growth factor 23 therapy in X-linked hypophosphatemia / 国际口腔科学杂志·英文版

Elevated fibroblast growth factor 23 (FGF23) in X-linked hypophosphatemia (XLH) results in rickets and phosphate wasting, manifesting by severe bone and dental abnormalities. Burosumab, a FGF23-neutralizing antibody, an alternative to conventional treatment (phosphorus and active vitamin D analogs), showed significant improvement in the long bone phenotype. Here, we examined whether FGF23 antibody (FGF23-mAb) also improved the dentoalveolar features associated with XLH. Four-week-old male Hyp mice were injected weekly with 4 or 16 mg·kg-1 of FGF23-mAb for 2 months and compared to wild-type (WT) and vehicle (PBS) treated Hyp mice (n = 3-7 mice). Micro-CT analyses showed that both doses of FGF23-mAb restored dentin/cementum volume and corrected the enlarged pulp volume in Hyp mice, the higher concentration resulting in a rescue similar to WT levels. FGF23-mAb treatment also improved alveolar bone volume fraction and mineral density compared to vehicle-treated ones. Histology revealed improved mineralization of the dentoalveolar tissues, with a decreased amount of osteoid, predentin and cementoid. Better periodontal ligament attachment was also observed, evidenced by restoration of the acellular cementum. These preclinical data were consistent with the retrospective analysis of two patients with XLH showing that burosumab treatment improved oral features. Taken together, our data show that the dentoalveolar tissues are greatly improved by FGF23-mAb treatment, heralding its benefit in clinics for dental abnormalities.

Mechanisms of PiT2-loop7 Missense Mutations Induced Pi Dyshomeostasis / 神经科学通报·英文版

PiT2 is an inorganic phosphate (Pi) transporter whose mutations are linked to primary familial brain calcification (PFBC). PiT2 mainly consists of two ProDom (PD) domains and a large intracellular loop region (loop7). The PD domains are crucial for the Pi transport, but the role of PiT2-loop7 remains unclear. In PFBC patients, mutations in PiT2-loop7 are mainly nonsense or frameshift mutations that probably cause PFBC due to C-PD1131 deletion. To date, six missense mutations have been identified in PiT2-loop7; however, the mechanisms by which these mutations cause PFBC are poorly understood. Here, we found that the p.T390A and p.S434W mutations in PiT2-loop7 decreased the Pi transport activity and cell surface levels of PiT2. Furthermore, we showed that these two mutations attenuated its membrane localization by affecting adenosine monophosphate-activated protein kinase (AMPK)- or protein kinase B (AKT)-mediated PiT2 phosphorylation. In contrast, the p.S121C and p.S601W mutations in the PD domains did not affect PiT2 phosphorylation but rather impaired its substrate-binding abilities. These results suggested that missense mutations in PiT2-loop7 can cause Pi dyshomeostasis by affecting the phosphorylation-regulated cell-surface localization of PiT2. This study helps understand the pathogenesis of PFBC caused by PiT2-loop7 missense mutations and indicates that increasing the phosphorylation levels of PiT2-loop7 could be a promising strategy for developing PFBC therapies.

Denitrifying phosphate accumulating organisms and its mechanism of nitrogen and phosphorus removal / 生物工程学报

Water eutrophication poses great threats to protection of water environment. Microbial remediation of water eutrophication has shown high efficiency, low consumption and no secondary pollution, thus becoming an important approach for ecological remediation. In recent years, researches on denitrifying phosphate accumulating organisms and their application in wastewater treatment processes have received increasing attention. Different from the traditional nitrogen and phosphorus removal process conducted by denitrifying bacteria and phosphate accumulating organisms, the denitrifying phosphate accumulating organisms can simultaneously remove nitrogen and phosphorus under alternated anaerobic and anoxic/aerobic conditions. It is worth noting that microorganisms capable of simultaneously removing nitrogen and phosphorus absolutely under aerobic conditions have been reported in recent years, but the mechanisms remain unclear. This review summarizes the species and characteristics of denitrifying phosphate accumulating organisms and the microorganisms capable of performing simultaneous nitrification-denitrification and phosphorous removal. Moreover, this review analyzes the relationship between nitrogen removal and phosphorus removal and the underlying mechanisms, discusses the challenges of denitrifying phosphorus removal, and prospects future research directions, with the aim to facilitate process improvement of denitrifying phosphate accumulating organisms.

Effect of recombinant human growth hormone on serum Klotho and fibroblast growth factor 23 in children with idiopathic short stature / 中国当代儿科杂志

OBJECTIVES@#To investigate the changes in the serum levels of Klotho, fibroblast growth factor 23 (FGF23), and insulin-like growth factor-1 (IGF-1) in children with idiopathic short stature (ISS) before and after recombinant human growth hormone (rhGH) treatment, as well as the correlation of Klotho and FGF23 with the growth hormone (GH)/IGF-1 growth axis in these children.@*METHODS@#A prospective study was conducted on 33 children who were diagnosed with ISS in the Department of Pediatrics, Hebei Provincial People's Hospital, from March 10, 2021 to December 1, 2022 (ISS group). Twenty-nine healthy children, matched for age and sex, who attended the Department of Child Healthcare during the same period, were enrolled as the healthy control group. The children in the ISS group were treated with rhGH, and the serum levels of Klotho, FGF23, and IGF-1 were measured before treatment and after 3, 6, and 9 months of treatment. A correlation analysis was conducted on these indexes.@*RESULTS@#There were no significant differences in the serum levels of IGF-1, Klotho, and FGF23 between the ISS and healthy control groups (P>0.05). The serum levels of Klotho, FGF23, and IGF-1 increased significantly in the ISS group after 3, 6, and 9 months of rhGH treatment (P<0.05). In the ISS group, Klotho and FGF23 levels were positively correlated with the phosphate level before treatment (P<0.05). Before treatment and after 3, 6, and 9 months of rhGH treatment, the Klotho level was positively correlated with the IGF-1 level (P<0.05), the FGF23 level was positively correlated with the IGF-1 level (P<0.05), and the Klotho level was positively correlated with the FGF23 level (P<0.05), while Klotho and FGF23 levels were not correlated with the height standard deviation of point (P>0.05).@*CONCLUSIONS@#The rhGH treatment can upregulate the levels of Klotho, FGF23, and IGF-1 and realize the catch-up growth in children with ISS. Klotho and FGF23 may not directly promote the linear growth of children with ISS, but may have indirect effects through the pathways such as IGF-1 and phosphate metabolism. The consistent changes in Klotho, FGF23 and IGF-1 levels show that there is a synergistic relationship among them in regulating the linear growth of ISS children.

Cost-effectiveness analysis of Chaiyin Granules in treatment of influenza / 中国中药杂志

This study aimed to evaluate the cost-effectiveness of Chaiyin Granules compared with Oseltamivir Phosphate Capsules in the treatment of influenza(exogenous wind-heat syndrome). Based on a randomized, double-blind, positive drug parallel control clinical trial, this study evaluated the pharmacoeconomics of Chaiyin Granules with cost-effectiveness analysis method. A total of 116 patients with influenza from eight hospitals(grade Ⅱ level A above) in 6 cities were selected in this study, including 78 cases in the experimental group with Chaiyin Granules and Oseltamivir Phosphate Capsules placebo, and 38 cases in the control group with Oseltamivir Phosphate Capsules and Chaiyin Granules placebo. The total cost of this study included direct medical cost, direct non-medical cost, and indirect cost. The remission time of clinical symptoms, cure time/cure rate, antipyretic onset time/complete antipyretic time, viral nucleic acid negative rate, and traditional Chinese medicine(TCM) syndrome curative effect were selected as the effect indicators for cost-effectiveness analysis. Four-quadrant diagram was used to estimate the incremental cost-effectiveness ratio. The results showed that Chaiyin Granules were not inferior to Oseltamivir Phosphate Capsules in the remission time of clinical symptoms of influenza(3.1 d vs 2.9 d, P=0.360, non-inferiority margin was 0.5 d). Compared with Oseltamivir Phosphate Capsules, Chaiyin Granules would delay the remission time of clinic symptoms of influenza for 1 d, but could save 213.9 yuan. 1 d delay in cure time could save 149.3 yuan; 1% reduction in the cure rate could save 8.2 yuan; 1 d delay in antipyretic onset time could save 295.4 yuan; 1 d delay in complete antipyretic time could save 114.3 yuan; 1% reduction in the 5-day cure rate of TCM syndrome could save 19.2 yuan. Different from other indicators, there was no statistically significant difference between two groups in the effect of negative conversion rate of viral nucleic acid, but the cost was lower and the effect was superior, and the pharmacoeconomics was not different from that of Oseltamivir Phosphate Capsules in the field of influenza treatment.

Phosphate and tension homology-induced kinase 1/Parkin signaling mediates cognitive dysfunction in sepsis-associated encephalopathy through activation of hippocampal mitochondrial autophagy / 中华危重病急救医学

OBJECTIVE@#To investigate the effects of gene of phosphate and tension homology (PTEN)-induced putative kinase 1 (PINK1)/Parkin pathway on hippocampal mitophagy and cognitive function in mice with sepsis-associated encephalopathy (SAE) and its possible mechanism.@*METHODS@#A total of 80 male C57BL/6J mice were randomly divided into Sham group, cecal ligation puncture (CLP) group, PINK1 plasmid transfection pretreatment groups (p-PINK1+Sham group, p-PINK1+CLP group), empty vector plasmid transfection control group (p-vector+CLP group), with 16 mice in each group. The mice in CLP groups were treated with CLP to reproduce SAE models. The mice in the Sham groups were performed laparotomy only. Animals in the p-PINK1+Sham and p-PINK1+CLP groups were transfected with PINK1 plasmid through the lateral ventricle at 24 hours before surgery, while mice in the p-vector+CLP group were transfected with the empty plasmid. Morris water maze experiment was performed 7 days after CLP. The hippocampal tissues were collected, the pathological changes were observed under a light microscope after hematoxylin-eosin (HE) staining, and the mitochondrial autophagy was observed under a transmission electron microscopy after uranyl acetate and lead citrate staining. The expressions of PINK1, Parkin, Beclin1, interleukins (IL-6, IL-1β) and microtubule-associated protein 1 light chain 3 (LC3) were detected by Western blotting.@*RESULTS@#Compared with the Sham group, CLP group mice in Morris water maze experiment had longer escape latency, shorter target quadrant residence time, and fewer times of crossing the platform at 1-4 days. Under the light microscope, the hippocampal structure of the mouse was injured, the neuronal cells were arranged in disorder, and the nuclei were pyknotic. Under the electron microscope, the mitochondria appeared swollen, round, and wrapped by bilayer or multilayer membrane structures. Compared with the Sham group, CLP group had higher expressions of PINK1, Parkin, Beclin1, LC3II/LC3I ratio, IL-6 and IL-1β in hippocampus, indicating that sepsis induced by CLP could activated inflammatory response and caused PINK1/Parkin-mediated mitophagy. Compared with the CLP group, p-PINK1+CLP group had shorter escape latencies, spent more time in the target quadrant and had more number of crossings in the target quadrant at 1-4 days. Under the light microscope, the hippocampal structures of mice was destroyed, the neurons were arranged disorderly, and the nuclei were pyknotic. Under transmission electron microscope, swollen and rounded mitochondria and mitochondrial structure wrapped by double membrane or multilayer membrane structure were observed. Compared with the CLP group, the levels of PINK1, Parkin, Beclin1 and LC3II/LC3 ratio in the p-PINK1+CLP group were significantly increased [PINK1 protein (PINK1/β-actin): 1.95±0.17 vs. 1.74±0.15, Parkin protein (Parkin/β-actin): 2.06±0.11 vs. 1.78±0.12, Beclin1 protein (Beclin1/β-actin): 2.11±0.12 vs. 1.67±0.10, LC3II/LC3I ratio: 3.63±0.12 vs. 2.27±0.10, all P < 0.05], while the levels of IL-6 and IL-1β were significantly decreased [IL-6 protein (IL-6/β-actin): 1.69±0.09 vs. 2.00±0.11, IL-1β protein (IL-1β/β-actin): 1.11±0.12 vs. 1.65±0.12, both P < 0.05], suggesting that overexpression of PINK1 protein could further activate mitophagy and reduce the inflammatory response caused by sepsis. There was no statistically significant difference in the above pathological changes and related indicators between Sham group and p-PINK1+Sham group, CLP group and p-vector+CLP group.@*CONCLUSIONS@#PINK1 overexpression can further activate CLP-induced mitophagy by upregulating Parkin, thereby inhibiting inflammation response and alleviate cognitive function impairment in SAE mice.

Endophytic bacteria Bacillus safensis and Pseudomonas hibiscicola and their ability to increase rice seedling growth

Endophytic bacteria Bacillus safensis RS95 and Pseudomonas hibiscicola RS121 were evaluated for their ability to promote the growth of rice seedlings and produce indole-acetic acid (IAA) and siderophores and to solubilize phosphates. 'Guri' rice seeds were immersed in bacterial endophyte cell suspensions (separated and two-strain mixed), as well as in Escherichia coli DH5α, phosphate-buffered saline (PBS) and water treatments (negative controls). Seeds were sown on agar-water in Petri plates placed vertically at an angle of 65°. The ability of plant growth-promoting endophytic bacteria (PGPEB) to produce IAA and siderophores was determined by Salkowski colorimetric and chrome azurol S (CAS) assays, respectively. Mineral phosphate solubilization activity was calculated by inoculating the endophytes onto medium containing insoluble phosphate. PGPEB showed a positive effect on the growth of rice seedlings, causing a mean growth of shoots and primary-roots of 60 and 67%, respectively. Bacterial strains also showed positive traits for IAA and siderophore production, as well as phosphate-solubilization activity

An injectable hydrogel/staple fiber composite for sustained release of CA4P and doxorubicin for combined chemotherapy of xenografted breast tumor in mice / 南方医科大学学报

OBJECTIVE@#To prepare an injectable hydrogel/staple fiber composite loaded with combretastain A-4 disodium phosphate (CA4P) and doxorubicin (DOX) and evaluate its antitumor efficacy via intratumoral injection.@*METHODS@#DOX-loaded PELA staple fibers (FDOX) were prepared using electro-spinning and cryo-cutting, and the drug distribution on the surface of the fibers was observed using a fluorescence microscope, and the encapsulation efficiency and loading capacity of FDOX were determined with a fluorospectro photometer. The fibers were then dispersed in CA4P-loaded PLGA-PEG-PLGA tri-block polymer solution at room temperature to obtain the hydrogel/staple fiber composite (GCA4P/FDOX). The thermo-sensitivity of this composite was determined by a test tube inverting method. An ultraviolet spectrophotometer and a fluorospectrophotometer were used to detect the release profile of CA4P and DOX, respectively. We observed in vivo gel formation of the composite after subcutaneous injection in mice. The in vitro cytotoxicity of GCA4P/FDOX composite in MCF-7 and 4T1 cells was assessed using cell Counting Kit-8 (CCK-8) reagent. In a mouse model bearing breast tumor 4T1 cell xenograft, we evaluated the antitumor efficacy of the composite by monitoring tumor growth within 30 days after intratumoral injection of the composite. HE staining, immunohistochemistry for Ki67 and immunofluorescence (TUNEL) assay were used for pathological examination of the tumor tissues 21 days after the treatments.@*RESULTS@#The average length of FDOX was 4.0±1.3 μm, and its drug loading capacity was (2.69±0.35)% with an encapsulation efficiency of (89.70±0.12)%. DOX was well distributed on the surface of the fibers. When the temperature increased to 37 ℃, the composite rapidly solidified to form a gel in vitro. Drug release behavior test showed that CA4P was completely released from the composite in 5 days and 87% of DOX was released in 30 days. After subcutaneous injection, the composite solidified rapidly without degradation at 24 h after injection. After incubation with GCA4P/FDOX for 72 h, only 30.6% of MCF-7 cells and 28.9% of 4T1 cells were viable. In the tumor-bearing mice, the tumor volume was 771.9±76.9 mm3 in GCA4P/FDOX treatment group at 30 days. Pathological examination revealed obvious necrosis of the tumor tissues and tumor cell apoptosis induced by intratumoral injection of G4A4P/FDOX.@*CONCLUSION@#As an efficient dual drug delivery system, this hydrogel/staple fiber composite provides a new strategy for local combined chemotherapy of solid tumors.

Influência do metil-jasmonato na formação de compostos voláteis do aroma em Bananas (Musa acuminata cv. Nanicão) e Laranjas (Citrus sinensis cv. Pera) / Influence of methyljasmonate on the formation of aroma volatile compounds in Bananas (Musa acuminata cv. Nanicão) and Oranges (Citrus sinensis cv. Pera)

O principal hormônio associado aos processos do amadurecimento é o etileno, porém, na formação de compostos voláteis nos frutos, observa-se que as auxinas, o ácido abscísico e os jasmonatos também podem atuar como reguladores. Estudos indicam que em frutos climatéricos deve haver uma interação entre o metil jasmonato (MeJA) e o etileno na formação de compostos voláteis, mas em frutos não-climatéricos tal interação não é tão evidente. Há evidências de que o MeJA atue na regulação de algumas vias metabólicas relacionadas ao amadurecimento em frutos, sendo capaz de induzir aumento na produção de várias classes de compostos voláteis, através da expressão de genes que codificam as enzimas relacionadas às suas vias biossintéticas. Neste sentido, o objetivo deste projeto foi avaliar o efeito do metil jasmonato sobre o padrão de produção de compostos voláteis do aroma em frutos climatéricos e não-climatéricos. Precedentes do laboratório de Química, Bioq. e Biol. Molecular de Alimentos indicam que o MeJA apresentou padrões diferentes de comportamento em frutos climatéricos e não-climatéricos no que tange a formação do aroma. Assim, o presente projeto tem por hipótese a diferença de influência que o MeJA exerce sobre a produção de compostos voláteis em frutos climatéricos e não-climatéricos. Para testar esta hipótese foi avaliado o efeito do tratamento com MeJA na produção de compostos voláteis do aroma durante o amadurecimento de banana (Musa acuminata, cv. Nanicão), como exemplo de fruto climatérico e laranja (Citrus sinensis cv Pêra) para não-climatéricos. Os frutos foram divididos em grupo controle e tratado com MeJA (10 ppm/24h), armazenados em caixas plásticas tampadas e lacradas. Após tratamento foram submetidos a análises diárias da produção de etileno por cromatrogafia gasosa (CG), cor da casca e pesagem. Baseado em escalas de cor e a polpa foi congelada em N2 líq. e armazenada a -80°C para posterior análise dos compostos voláteis por cromatografia gasosa acoplada à espectrometria de massas (GC-MS). Ésteres, álcoois, cetonas e aldeídos foram compostos majoritariamente identificados na banana e terpenos, aldeídos, ésteres na laranja. As Bananas sofreram influência no perfil de acetato de isoamila, butonoato de butila, isobutirato de isoamila e isolvalerato de isoamila do começo ao fim do tratamento com MeJA, e as laranjas o tratamento influenciou os compostos Cis-muirola-3-5-diene, gamageraniol, alfa-copaeno, valenceno, alfa-pineno, carvone, geranial, entre outros terpenos, aldeídos como 3-hexanal e 2-hexenal (E) e ésteres como butirato de etila, nerol e tiglato de etilo. Os ésteres em frutos são produzidos por várias isoformas das álcool acil transferases (AATs). Estudos explicam que, ao menos 31 transcritos de AATs foram identificados em bananas, sendo 8 com altos níveis de expressão. Assim, é plausível supor que tal variedade de transcritos, e por conseguinte as AATs que codificam, sejam reguladas por múltiplos fatores, o que pode incluir o MeJa dentre outros sinais hormonais. Os terpenos são formados a partir de duas rotas, a do ácido mevalônico (MVA) e a rota do metileritritol fosfato (MEP). Compostos como, D-limoneno (51) e beta-selineno (62) tiveram níveis relativos maiores nos frutos do grupo controle, enquanto compostos terpênicos como geranial (59), valenceno (79) e o-cimeno (128), apresentaram maiores níveis nos frutos tratados com MeJa, no primeiro dia após o tratamento. Os resultados mostraram que o tratamento hormonal com MeJA causou mudanças do início ao fim do amadurecimento na composição do aroma de bananas (Musa acuminata cv Nanicão) e laranjas (Citrus sinensis cv Pera)

The main hormone associated with ripening processes is ethylene, but in the formation of volatile compounds in fruits, auxins, abscisic acid and jasmonates can also act as regulators. Studies indicate that in climacteric fruits there should be an interaction between methyl jasmonate (MeJA) and ethylene in the formation of volatile compounds, but in nonclimacteric fruits such interaction is not so evident. There is evidence that MeJA acts in the regulation of some metabolic pathways related to fruit ripening, being able to induce an increase in the production of several classes of volatile compounds, through the expression of genes that encode enzymes related to their biosynthetic pathways. In this sense, the objective of this project was to evaluate the effect of methyl jasmonate on the production pattern of aroma volatile compounds in climacteric and non-climacteric fruits. Precedents from the Laboratory of Food Chemistry, Bioq. and Molecular Biol. Molecular Chemistry, Bioq. and Molecular Biol. of Foods laboratory indicate that MeJA showed different behavior patterns in climacteric and non-climacteric fruits regarding aroma formation. Thus, the present project hypothesizes the different influence that MeJA has on the production of volatile compounds in climacteric and non-climacteric fruits. To test this hypothesis the effect of MeJA treatment on the production of volatile aroma compounds during ripening of banana (Musa acuminata, cv. Nanicão) as an example for climacteric fruit and orange (Citrus sinensis cv Pêra) for non-climacteric fruit was evaluated. Fruits were divided into control and MeJA treated group (10 ppm/24h), stored in capped and sealed plastic boxes. After treatment they were subjected to daily analysis of ethylene production by gas chromatography (GC), peel color and weighing. Based on color scales and the pulp was frozen in liquid N2 and stored at -80°C for subsequent analysis of volatile compounds by gas chromatography coupled to mass spectrometry (GC-MS). Esters, alcohols, ketones and aldehydes were compounds mostly identified in banana and terpenes, aldehydes, esters in orange. Bananas were influenced in the profile of isoamyl acetate, butyl butonoate, isoamyl isobutyrate and isoamyl isolvalerate from the beginning to the end of the MeJA treatment, and oranges the treatment influenced the compounds Cis-myrola-3-5-diene, gamma-geraniol, alpha-copaene, valencene, alpha-pinene, carvone, geranial, among other terpenes, aldehydes like 3-hexanal and 2-hexenal (E), and esters like ethyl butyrate, nerol, and ethyl tiglate. Esters in fruits are produced by various isoforms of the alcohol acyl transferases (AATs). Studies explain that at least 31 AAT transcripts have been identified in bananas, 8 of which have high expression levels. Thus, it is plausible to assume that such a variety of transcripts, and therefore the AATs they encode, are regulated by multiple factors, which may include MeJa among other hormonal signals. Terpenes are formed from two routes, the mevalonic acid (MVA) route and the methylerythritol phosphate (MEP) route. Compounds such as, D-limonene (51) and beta-selinene (62) had higher relative levels in the fruits of the control group, while terpenic compounds such as geranial (59), valencene (79) and o-cymene (128), showed higher levels in the MeJa treated fruits on the first day after treatment. The results showed that the hormonal treatment with MeJA caused changes from the beginning to the end of ripening in the aroma composition of bananas (Musa acuminata cv Nanicão) and oranges (Citrus sinensis cv Pera)

Efeito do trimetafosfato de sódio micro e nanoparticulado, associadas ou não ao fluoreto, sobre biofilmes mistos de Streptococcus mutans e Candida albicans: avaliação da composição orgânica e inorgânica / Effect of micro and nanoparticulate sodium trimetaphosphate, associated or not with fluoride, on mixed biofilms of Streptococcus mutans and Candida albicans: evaluation of organic and inorganic composition

Este estudo avaliou o efeito de nanopartículas de TMP (TMPn) sobre a composição inorgânica e componentes da matriz extracelular de biofilmes mistos de Streptococcus mutans e Candida albicans. Biofilmes de duas espécies de S. mutans e C. albicans foram cultivados em saliva artificial em placas de 6 poços e tratados três vezes (72, 78 e 96 h após o início de sua formação), por 1 minuto, com soluções contendo TMP microparticulado (TMPm) e TMPn nas concentrações de 1% e 3%, combinadas ou não com 1100 ppm F. Além disso, solução de 1100 ppm F (F) e saliva artificial (CTL) foram testadas como controles positivos e negativos, respectivamente. Após o último tratamento, a composição da matriz extracelular foi analisada em termos de proteína e carboidrato, e o pH e as concentrações de F, cálcio (Ca), fósforo (P) e P do TMP da biomassa e fluido do biofilme foram determinadas. Em outro conjunto de experimentos, após o último tratamento, os biofilmes foram expostos a uma solução de sacarose a 20%, e o pH e componentes inorgânicos dos biofilmes foram avaliados conforme mencionado acima. Os dados de proteínas e carboidratos foram submetidos a ANOVA a 1 critério, seguido pelo teste de Student-Newman-Keuls, enquanto os dados da composição inorgânica do biofilme foram submetidos a ANOVA a 2 critérios, seguido pelo teste de Fisher LSD (p< 0,05). Tratamentos com TMPn a 3% combinado com F levou a reduções significativamente maiores nas concentrações de carboidratos da matriz extracelular, maior concentração iônica de F no fluido, e um pH significativamente mais alto, se comparado a todos os outros grupos. Além disso, TMPn a 3% sem F levou a concentrações de P significativamente mais altas em comparação a todos os outros grupos, antes da exposição a sacarose. Conclui-se que o TMPn afetou a composição da matriz extracelular, o pH dos biofilmes analisados, além de interferir nos componentes inorgânicos dos biofilmes ao aumentar os níveis de fósforo no fluido do biofilme(AU)

This study evaluated the effect of TMP nanoparticles (nTMP) on the inorganic composition and extracellular matrix components of mixed biofilms of Streptococcus mutans and Candida albicans. Biofilms of two species of S. mutans and C. albicans were cultivated in artificial saliva in 6-well plates and treated three times (72, 78 and 96 h after the beginning of their formation), for 1 minute, with Solutions containing microparticulate TMP (TMPm) and TMPn at concentrations of 1% and 3%, combined or not with 1100 ppm F. In addition, 1100 ppm F (F) solution and artificial saliva (CTL) were tested as positive and negative controls, respectively. After the last treatment, the composition of the extracellular matrix was analyzed in terms of protein and carbohydrate, and the pH and concentrations of F, calcium (Ca), phosphorus (P) and P of the TMP of the biomass and biofilm fluid were determined. In another set of experiments, after the last treatment, the biofilms were exposed to a 20% sucrose solution, and the pH and inorganic components of the biofilms were evaluated as mentioned above. Protein and carbohydrate data were subjected to 1-way ANOVA, followed by the Student-Newman-Keuls test, while biofilm inorganic composition data were subjected to 2-way ANOVA, followed by the Fisher LSD test (p< 0 .05). Treatments with 3% nTMP combined with F led to significantly greater reductions in extracellular matrix carbohydrate concentrations, and significantly higher pH, compared to all other groups. In addition, 3% nTMP without F led to significantly higher P concentrations compared to all other groups before sucrose exposure. It is concluded that TMPn affected the composition of the extracellular matrix, the pH of the analyzed biofilms, in addition to interfering with the inorganic components of the biofilms by increasing phosphorus levels in the biofilm fluid(AU)

Efeito de soluções contendo hexametafosfato de sódio e quercetina, associados ou não ao fluoreto, sobre o desgaste erosivo dentinário in vitro / Effect of sodium hexametaphosphate and quercetin, associated or not with fluoride, on dentin erosion in vitro

O objetivo do presente estudo foi investigar o efeito de soluções contendo fluoreto (F), hexametafosfato de sódio (HMP) e quercetina (QC), sozinhos ou em associação, sobre a erosão dentinária e sobre a inibição de metaloproteinases da matriz (MMPs) -2 e -9, em protocolos in vitro. Blocos de dentina radicular bovina (4 × 4 × 2 mm; n = 96), selecionados por dureza superficial, foram aleatoriamente divididos em 8 grupos experimentais (n = 12/grupo) e tratados 2×/dia (um minuto) com as seguintes soluções: (1) água deionizada (controle negativo); (2) 1100 ppm F ("F"); (3) 1,0% HMP ("HMP"); (4) 0,03% QC ("QC"); (5) F+HMP; (6) F+QC; (7) HMP+QC; e (8) F+HMP+QC. Os blocos foram submetidos a desafios erosivos 4×/dia, por 5 dias (exposição dinâmica a ácido cítrico 50 mmol.l-1 , pH 3,2, 90 s). Em seguida, foram analisados quanto à perda dentinária (perfilometria) e à perda de dureza integrada em profundidade (área sob a curva, ∆KHN). O potencial antiproteolítico das soluções contendo F, HMP e/ou QC foi analisado por zimografia. Os dados de perda dentinária (log10) foram submetidos a ANOVA um critério, seguido do teste de Tukey. Os resultados de ∆KHN (dados brutos) foram submetidos a ANOVA dois critérios, medidas repetidas, seguido do teste HolmSidak (p< 0,05). O menor desgaste erosivo foi observado no grupo F+HMP+QC. Nas menores profundidades (5-30 µm), os blocos tratados com a solução contendo F+HMP+QC apresentaram os maiores valores de ∆KHN. A análise zimográfica mostrou que todos os tratamentos promoveram atividade antiproteolítica total da MMP-2, com exceção da QC administrada sozinha (inibição de 77%). Para MMP-9, todas as soluções contendo HMP e a associação de F+QC apresentaram atividade antiproteolítica total. Conclui-se que a adição de HMP e QC a soluções contendo F levou a uma maior proteção contra a erosão dentinária, tanto em superfície (perda dentinária) quanto em relação ao conteúdo mineral do tecido remanescente (∆KHN), além de promover uma completa inibição da atividade de MMPs -2 e -9 in vitro(AU)

The aim of the present study was to investigate the effect of solutions containing fluoride (F), sodium hexametaphosphate (HMP) and quercetin (QC), alone or in association, on dentin erosion and on the inhibition of matrix metalloproteinases (MMPs) - 2 and -9, using in vitro protocols. Bovine root dentin blocks (4 × 4 × 2 mm; n = 96), selected by surface hardness, were randomly divided into 8 experimental groups (n = 12/group) and treated 2×/day (one minute) with the following solutions: (1) deionized water (negative control); (2) 1100 ppm F ("F"); (3) 1.0% HMP ("HMP"); (4) 0.03% QC ("QC"); (5) F+HMP; (6) F+QC; (7) HMP+QC; and (8) F+HMP+QC. Blocks were submitted to erosive challenges 4×/day for 5 days (dynamic exposure to 50 mmol.l-1 citric acid, pH 3.2, 90 s). They were then analyzed for dentin loss (profilometry) and integrated hardness loss in depth (area under the curve, ∆KHN). The antiproteolytic potential of solutions containing F, HMP and/or QC was analyzed by zymography. Dentin loss results (log10 transformed) were submitted to one-way ANOVA, followed by Tukey's test. ∆KHN data (raw) were submitted to two-way, repeated-measures ANOVA, followed by the Holm-Sidak test (p< 0.05). The lowest dentin erosive wear was promoted by F+HMP+QC. At the lowest depths (5-30 µm), blocks treated with F+HMP+QC showed the highest values of ∆KHN. Zymography analysis showed that all treatments completely inhibited MMP-2 activity, except for QC administered alone (77% inhibition). For MMP-9, all the solutions containing HMP or the association of F+QC promoted total antiproteolytic activity. It was concluded that the addition of HMP and QC to F solutions led to greater protection against dentin erosion, both at the surface (dentin loss) and in relation to the mineral content of the remaining tissue (∆KHN), in addition to promoting a complete inhibition of MMPs -2 and -9 activity in vitro(AU)

Efeitos de nanopartículas de hexametafosfato de sódio, associadas ou não ao fluoreto, em biofilmes mistos de Streptococcus mutans e Candida albicans e em biofilmes microcosmos / Effects of sodium hexametaphosphate nanoparticles, combined or not with fluoride, on dual-species biofilms of Streptococcus mutans and Candida albicans and on microcosm biofilms

O presente estudo avaliou os efeitos de nanopartículas de hexametafosfato de sódio (HMPnano), associadas ou não ao fluoreto (F), na composição orgânica (Subprojeto 1- S1) e inorgânica (Subprojeto 2-S2) de biofilmes mistos de Streptococcus mutans e Candida albicans formados in vitro; e na viabilidade celular e atividade metabólica de biofilmes microcosmos derivados de saliva (Subprojeto 3-S3). Em S1 e S2, soluções de HMPnano ou HMP microparticulado (HMPmicro) foram preparadas a 0,5% ou 1%, com ou sem F (1100 ppm F, NaF), além de 1100 ppm F (controle positivo) e saliva artificial (controle negativo). S. mutans e C. albicans foram cultivados em saliva artificial. Os biofilmes foram formados no fundo de poços de placas de microtitulação e tratados 72, 78 e 96 horas após o início da formação, por 1 minuto. Em S1, após o último tratamento, realizou-se análises de quantificação das unidades formadoras de colônias (UFCs), produção de biomassa total, atividade metabólica, além da composição da matriz extracelular dos biofilmes e avaliação estrutural. Observou-se que 1% de HMPnano combinado ao F levou aos menores UFCs de S. mutans, bem como às menores concentrações de carboidratos da matriz extracelular dos biofilmes, além de afetar substancialmente a sua estrutura. Em S2, após o último tratamento, avaliou-se o pH e a composição inorgânica dos biofilmes (análise das concentrações de F, cálcio (Ca) e fósforo (P)), antes e após exposição a sacarose. Soluções contendo 1% HMPnano combinado ao F promoveram os maiores valores de pH dos biofilmes, mesmo após exposição à sacarose. Além disso, 1% HMPnano promoveu maiores concentrações de P, enquanto que o HMP (micro/nano, com/sem F) levou a concentrações inexpressivas de Ca no fluido do biofilme. Em S3, os efeitos do HMPmicro ou HMPnano, sozinhos ou associados ao F, foram avaliados em biofilmes microcosmos derivados de saliva. Os biofilmes foram formados sobre discos de vidro por 24 h e, em seguida, S. mutans (C180- 2) foi incorporado ou não aos biofilmes. A partir deste momento, os mesmos ativos avaliados em S1/S2 foram adicionados ao meio de cultura, a 20% das concentrações utilizadas nesses subprojetos. Após 96 h de formação, foram determinadas as UFCs totais e de S. mutans, e avaliada a produção de ácido láctico pelos biofilmes. Todos os meios de cultura contendo contendo HMP levaram às menores concentrações de ácido láctico e às maiores reduções de UFCs totais e de S. mutans dos biofilmes, sem influência do tamanho da partícula de HMP, associação com F ou adição de S. mutans. Conclui-se que o HMPnano a 1%, associado a 1100 ppm F, promoveu uma diminuição substancial no metabolismo de biofilmes mistos de S. mutans e C. albicans, e da viabilidade de S. mutans. Esta combinação também levou a valores de pH mais próximos do neutro, além de afetar a composição inorgânica destes biofilmes. Para biofilmes microcosmos, o HMP promoveu a diminuição da viabilidade microbiana e acidogenicidade, sem influência, entretanto, do tamanho da partícula de HMP e da presença de F(AU)

This study evaluated the effects of sodium hexametaphosphate nanoparticles (HMPnano), combined or not with fluoride (F), on the organic (Subproject 1-S1) and inorganic (Subproject 2-S2) compositions of dual-species biofilms of Streptococcus mutans and Candida albicans formed in vitro; and on the cell viability and metabolic activity of saliva-derived microcosms biofilms (Subproject 3-S3). In S1 and S2, solutions containing HMPnano or conventional/micrometric HMP (HMPmicro) were prepared at 0.5 or 1%, combined or not with F (1,100 ppm F, as NaF). Also, a solution containing 1,100 ppm F and pure artificial saliva were tested as positive and negative controls, respectively. S. mutans and C. albicans strains were cultivated in artificial saliva. The biofilms were formed in well plates, and treated with the test solutions at 72, 78 and 96 from the beginning of the biofilm formation, for 1 minute. In S1, after the last treatment, the number of the colony-forming units (CFUs), production of total biomass, metabolic activity, composition of the extracellular matrix, and the structure of the biofilms were determined. HMP at 1% combined with F led to the lowest S. mutans CFUs and lowest concentration of carbohydrates from the extracellular matrix of the biofilms, besides substantially affecting biofilm's structure. In S2, after the last treatment, the pH and the inorganic composition of the biofilms (analysis of F, calcium (Ca), and phosphorus (P) concentrations), prior to and after sucrose exposure, were evaluated. Solutions containing 1% HMPnano combined with F led to the highest biofilm pH, even after exposure to sucrose. In addition, 1% HMPnano promoted the highest P concentrations, while HMP (micro/nano, with/without F) led to inexpressive Ca levels in the biofilm fluid. In S3, the effects of HMPmicro or HMPnano, alone or associated with F, were evaluated in salivaderived microcosm biofilms, which were formed during 24 h attached to glass coverslips. Thereafter, S. mutans (C180-2) was incorporated to the biofilms. From that timepoint onwards, the same actives analyzed in S1/S2 were added to the culture medium at 20% of the concentrations used in those subprojects. After 96 h of formation, total and S. mutans CFU-counting were determined, and the production of lactic acid was assessed. All HMP-containing culture media led to the lowest lactic acid concentrations, and to the highest reductions in total and S. mutans CFU counts, with no significant influence of HMP's particle size, association with F or the addition of S. mutans. In summary, it was concluded from S1 and S2 that 1% HMPnano combined with 1,100 ppm F substantially reduced the metabolism of S. mutans and C. albicans dual-species biofilms, besides reducing the viability of S. mutans. Also, this combination led to biofilm pH values closer to neutral ones, besides affecting their inorganic composition. From S3, HMP promoted reductions in the microbial viability and acidogenicity, without the influence, however, of HMP's particle size or the presence of F(AU)

Efeito de géis fluoretados suplementados com trimetafosfato de sódio nanoparticulado sobre a remineralização do esmalte dental in situ / Effect of fluoride gels supplemented with nanosized sodium trimetaphosphate on enamel remineralization in situ

O objetivo do presente estudo foi avaliar o efeito de géis fluoretados suplementados com nanopartículas de Trimetafosfato de Sódio (TMP) sobre a remineralização de lesões de cárie artificiais in situ. Blocos de esmalte dental bovino (n=160) foram aleatoriamente divididos entre os grupos de estudo após análise de dureza de superfície (DS) e indução de lesões de subsuperfície. Os géis testados foram: Placebo (sem flúor ou TMP ­ controle negativo), 9000 µg F/g (9000F ­ controle positivo), 4500 µg F/g + 5% TMP microparticulado (4500 5%TMPmicro) e 4500 µg F/g + 5% TMP nanoparticulado (4500 5%TMPnano). Dez voluntários utilizaram dispositivos palatinos contendo 4 blocos de esmalte durante 3 dias, após uma única aplicação dos géis, seguindo um protocolo duplo-cego e cruzado. Dois blocos de esmalte foram removidos imediatamente após a aplicação dos géis, para determinar a concentração de fluoreto de cálcio (CaF2) formado. Após cada fase, determinou-se a porcentagem de recuperação de dureza de superfície (%RDS) e CaF2 retido no esmalte. Os dados foram submetidos ANOVA de medidas repetidas e teste de Student-Newman-Keuls (p< 0.05). A maior %RDS foi observada para o gel 4500 5%TMPnano, seguido por 4500 5%TMPmicro, 9000F e Placebo, com diferenças significativas entre os grupos. Em relação ao CaF2 formado, a maior concentração foi observada para o grupo 9000F. Não foram observadas diferenças significativas entre os grupos 9000F, 4500 5%TMPmicro e 4500 5%TMPnano para concentrações de CaF2 retido. Conclui-se que a adição de TMP a géis fluoretados melhorou significativamente a remineralização de lesões de cárie in situ. O uso de TMP em escala nanométrica potencializou ainda mais este efeito(AU)

The present study aimed to evaluate the effect of fluoride gels supplemented with nano-sized sodium trimetaphosphate (TMP) on the remineralization of artificial caries lesions in situ. Bovine enamel blocks (n=160) were randomly distributed among study groups after surface microhardness (SH) analysis and induction of subsurface lesions. Test groups included: Placebo (without F and TMP ­ negative control), 9000 µg F/g (9000F ­ positive control), 4500 µg F/g + 5% micrometric TMP (4500 5%+ TMPmicro) and 4500 µg F/g + 5% nano-sized TMP (4500 + 5%TMPnano). Ten volunteers used palatal devices containing 4 enamel blocks during 3 days, after a single application of gels, following a double-blind and crossover protocol. Two enamel blocks were removed immediately after topical application of F to determine calcium fluoride (CaF2) formed on enamel. After each phase, the samples were analyzed by percentage of surface hardness recovery (%SHR) and CaF2 retained on enamel. Data were analyzed by repeated-measures ANOVA and Student-NewmanKeuls test (p< 0.05). The highest %SHR was observed for 4500 5%TMPnano gel, following by 4500 5%TPMmicro, 9000F, and Placebo, with significant differences among all groups. Regarding CaF2 formed, the highest concentration was observed in the 9000F group. No significant differences were observed among 9000F, 4500 5%TMPmicro and 4500 5%TMPnano groups for concentrations of CaF2 retained. It was concluded that the addition of TMP to gels improved the remineralization of caries lesions in situ. The use of nano-sized TMP further enhanced this effect(AU)

Tanshinone IIa attenuates vascular calcification through inhibition of NF-κB and β-catenin signaling pathways / 生理学报

Tanshinone IIa is a key ingredient extracted from the traditional Chinese medicine Salvia miltiorrhiza (Danshen), and is widely used to treat various cardiovascular diseases. Vascular calcification is a common pathological change of cardiovascular tissues in patients with chronic kidney disease, diabetes, hypertension and atherosclerosis. However, whether Tanshinone IIa inhibits vascular calcification and the underlying mechanisms remain largely unknown. This study aims to investigate whether Tanshinone IIa can inhibit vascular calcification using high phosphate-induced vascular smooth muscle cell and aortic ring calcification model, and high dose vitamin D3 (vD3)-induced mouse models of vascular calcification. Alizarin red staining and calcium quantitative assay showed that Tanshinone IIa significantly inhibited high phosphate-induced vascular smooth muscle cell and aortic ring calcification. qPCR and Western blot showed that Tanshinone IIa attenuated the osteogenic transition of vascular smooth muscle cells. In addition, Tanshinone IIa also significantly inhibited high dose vD3-induced mouse aortic calcification and aortic osteogenic transition. Mechanistically, Tanshinone IIa inhibited the activation of NF-κB and β-catenin signaling in normal vascular smooth muscle cells. Similar to Tanshinone IIa, inhibition of NF-κB and β-catenin signaling using the chemical inhibitors SC75741 and LF3 attenuated high phosphate-induced vascular smooth muscle cell calcification. These results suggest that Tanshinone IIa attenuates vascular calcification at least in part through inhibition of NF-κB and β-catenin signaling, and Tanshinone IIa may be a potential drug for the treatment of vascular calcification.

Caracterización microscópica de la dentina de dientes temporales / Microscopic characterization of the dentin of temporary teeth

La dentina se compone de un mineral de fosfato de calcio identificado como dahllita, que se dispone en pequeños cristales de hidroxiapatita carbonatada con dimensiones de 36 × 25 × 4 nm, y por una fase orgánica cuyo principal componente es el colágeno tipo 1 en 90%, que se orienta en forma de malla. Esta conformación corresponde a los dientes permanentes. Dentro de las estructuras, encontramos túbulos dentinarios que miden, aproximadamente, entre 0.5-1 µm de diámetro en la periferia y hasta 3-5 µm cerca de la pulpa. En el presente estudio, realizado en dentina de dientes temporales, el lumen de dichos túbulos es más grande cuando se encuentra cerca de la pulpa dental. Asimismo, se encontraron cambios elementales importantes de acuerdo con las diferentes profundidades en las que se observó, encontrando un aumento en el peso porcentual de carbono cuando se encuentra a mayor profundidad, lo que indica una composición orgánica mayor en la dentina pulpar. En estudios de dientes permanentes esta composición es disminuida y con mayor concentración en la dentina cercana a la unión amelodentinaria. En dentina de dientes temporales se encontraron diferencias en el recuento de túbulos dentinarios por mm2, comparado a la dentina de dientes permanentes, donde el número de túbulos no varía mucho (AU)

Dentin is composed of a calcium phosphate mineral identified as dahllite, which is arranged in small crystals of carbonated hydroxyapatite with dimensions of 36 × 25 × 4 nm, and by an organic phase whose main component is type l collagen in 90%, which is oriented in the form of a mesh. This conformation corresponds to permanent teeth. Within the structures, we find dentin tubules that measure approximately 0.5-1 µm in diameter at the periphery and up to 3-5 µm near the pulp. In the present study, carried out in dentin of primary teeth, the lumen of these tubules is larger when it is close to the dental pulp. Likewise, important elemental changes were found according to the different depths in which it was observed, finding an increase in the percentage weight of carbon when it is at a greater depth, indicating a greater organic composition in the pulp dentin. In studies of permanent teeth, this composition is decreased and with a higher concentration in the dentin near the amelodentinal junction. In dentin of primary teeth, differences were found in the count of dentin tubules per mm2, compared to dentin of permanent teeth, where the number of tubules did not vary much (AU)

Nefropatía aguda por fosfatos secundaria al uso de laxantes con fosfato de sodio: caso clínico-patológico / Acute phosphate nephropathy secondary to the use of oral sodium phosphate laxatives: report of one case

Acute phosphate nephropathy (APN) is an acute renal failure secondary to the use of oral sodium phosphate (OSP) laxatives, with a high risk of progression to chronicity. We report a 60-year-old woman with mixed connective tissue disease whose serum creatinine increased up to 2.0 mg/dL in her regular control tests, without an evident causative factor. Kidney biopsy showed numerous intratubular calcium phosphate deposits, consistent with APN. She had a history of OSP laxative intake, and a sodium phosphate enema was used before a colonoscopy performed six months earlier. The temporal association between the use of OSP laxatives and acute kidney injury, should lead to the suspicion of APN. The urine sediment is generally normal or with mild to moderate proteinuria. The diagnosis is confirmed with a kidney biopsy. Until now, there is no specific treatment for APN, thus prevention is essential. In high-risk patients for developing APN, the administration of these laxatives should be avoided.