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1.
Zhongguo Dang Dai Er Ke Za Zhi ; 23(4): 375-380, 2021 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-33840410

RESUMO

OBJECTIVE: To study the risk factors and treatment for neutropenia of late newborns (NLN). METHODS: Related clinical data were collected from the preterm infants and critically ill neonates who were admitted to the neonatal intensive care unit from July 2019 to January 2020. A total of 46 newborns with a blood absolute neutrophil count (ANC) of < 1.5×109/L for two consecutive times at weeks 2-4 after birth were enrolled as the NLN group. A total of 92 late newborns with a blood ANC of ≥ 1.5×109/L, matched at a ratio of 1:2, were enrolled as the control group. Possible risk factors associated with NLN and the treatment process were recorded. A logistic regression analysis was performed to identify the risk factors for NLN. RESULTS: Among the 46 neonates in the NLN group, 29 had a gestational age of < 32 weeks, 14 had a gestational age of 32-37 weeks, and 3 had a gestational age of > 37 weeks. There was no significant difference between the two groups in the incidence rates of gestational hypertension, premature rupture of membranes > 18 hours and intrauterine distress, 5-minute Apgar score, the duration of positive pressure ventilation, the incidence rate of early-onset sepsis, and the type of initially used antibiotics (P > 0.05). Compared with the control group, the NLN group had a higher incidence rate of late-onset sepsis and a longer duration of antibiotic use (P < 0.05). Late-onset sepsis and prolonged duration of antibiotic use were independent risk factors for NLN (P < 0.05). With the presence of late-onset sepsis, the risk of NLN was increased by 1.537 times in neonates, and the risk of NLN was increased by 76.9% for every 3-day increase in the duration of antibiotic use. The mean age at the diagnosis of NLN was (21±6) days for the 46 neonates in the NLN group. Thirteen neonates with NLN were administered with recombinant human granulocyte colony-stimulating factor (G-CSF, 10 µg/kg) once or twice. O the 13 neonates, 6 had an ANC of < 0.5×109/L and 7 had a gestational age of < 32 weeks or severe disease conditions. After treatment the ANC returned to > 1.0×109/L in the 13 neonates. No drug-related adverse reactions were found. After the diagnosis of NLN, 2 neonates developed sepsis, and the remaining 44 neonates did not develop any common purulent infections. CONCLUSIONS: The risk of NLN increases with the presence of late-onset sepsis and the increase in the duration of antibiotic use. NLN is generally a benign process. G-CSF appears to be safe and effective for NLN with severe disease conditions or severe reduction in ANC.


Assuntos
Neutropenia , Sepse , Fator Estimulador de Colônias de Granulócitos , Humanos , Lactente , Recém-Nascido , Recém-Nascido Prematuro , Contagem de Leucócitos , Fatores de Risco
2.
Front Endocrinol (Lausanne) ; 12: 620941, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33679618

RESUMO

Vitamin A (VA), which is stored in several forms in most tissues, is required to maintain metabolite homeostasis and other processes, including the visual cycle, energy balance, epithelial cell integrity, and infection resistance. In recent years, VA molecules, also known as retinoids, have been extensively explored and used in the treatment of skin disorders and immune-related tumors. To date, several observational and interventional studies have explored the relationship between VA status and the pathogenesis of diabetes. In particular, VA micronutrients have been shown to regulate pancreatic development, ß-cell function, pancreatic innate immune responses, and pancreatic stellate cells phenotypes through multiple mechanisms. However, there are still many problems to be proven or resolved. In this review, we summarize and discuss recent and available evidence on VA biological metabolism in the pancreas. Analysis of the effects of VA on metabolism in the pancreas will contribute to our understanding of the supportive physiological roles of VA in pancreas protection.

3.
Small ; : e2007570, 2021 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-33734588

RESUMO

Halogen-bond driven assembly, a world parallel to hydrogen-bond, has emerged as an attractive tool for constructing (macro)molecular arrangement. However, knowledge about halogen-bond mediated confined-assembly in emulsion droplets is limited so far. An I…. N bond mediated confined-assembly pathway to enable order-order phase transitions is reported here. Compared to hydrogen bonds, the distinct features of halogen bonds (e.g., higher directionality, hydrophobicity, favored in polar solvents), offers opportunities to achieve novel nanostructures and materials. Polystyrene-b-poly(4-vinyl pyridine) (PS-b-P4VP) AB diblock copolymer is chosen as halogen acceptor, while an iodotetrafluorophenoxy substituted C-type homopolymer, (poly(3-(2,3,5,6-tetrafluoro-4-iodophenoxy)propyl acrylate), PTFIPA) is designed as halogen donor, synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization. Formation of halogen bonding donor-acceptor pairs between the PTFIPA homopolymer and the P4VP segments presented in PS-b-P4VP, increase the volume of P4VP domains, in turn inducing an order-to-order morphology transition sequence: changing from spherical → cylindrical → lamellar → inverse cylindrical, by tuning the PTFIPA content and choice of surfactant. Subsequent selective swelling/deswelling of the P4VP domains give rise to further internal morphology transitions, creating tailored mesoporous microparticles, disassembled nanodiscs, and superaggregates. It is believed that these results will stimulate further examinations of halogen bonding interactions in emulsion droplets and many areas of application.

4.
Talanta ; 226: 122129, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33676683

RESUMO

The development of in situ methods for the analysis and visualization of enzyme activity is of paramount importance in drug discovery, research, and development. In this work, the functionalized and array patterned indium tin oxide (ITO) glass slides were fabricated by non-covalent immobilization of amphipathic phospholipid-tagged peptides encompassing the thrombin cleavage site on steric acid-modified ITO slides. The fabricated peptide arrays provide 60 spots per slide, and are compatible with matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) measurement, free matrix peak interference, and tolerance to repeated aqueous washing. The peptide arrays were used for the investigation of thrombin activity and screening for its potential inhibitors. The thrombin activity and its Michaelis-Menten constant (Km) for immobilized peptide substrate was determined using developed MALDI MS peptide array. To investigate the applicability and effectiveness of peptide arrays, the anti-thrombin activity of grape seed proanthocyanidins with different degrees of polymerization (DP) was monitored and visualized. MALDI MS imaging results showed that the fractions of proanthocyanidins with the mean DP of 4.61-6.82 had good thrombin inhibitory activity and their half-maximal inhibitory concentration (IC50) were below 10 µg/mL. Therefore, the developed peptide array is a reliable platform for the discovery of natural thrombin inhibitors.

5.
Sci Rep ; 11(1): 4479, 2021 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-33627763

RESUMO

It is well-known that antibiotics affect commensal gut bacteria; however, only recently evidence accumulated that gut microbiota (GM) can influence the central nervous system functions. Preclinical animal studies have repeatedly highlighted the effects of antibiotics on brain activity; however, translational studies in humans are still missing. Here, we present a randomized, double-blind, placebo-controlled study investigating the effects of 7 days intake of Rifaximin (non-absorbable antibiotic) on functional brain connectivity (fc) using magnetoencephalography. Sixteen healthy volunteers were tested before and after the treatment, during resting state (rs), and during a social stressor paradigm (Cyberball game-CBG), designed to elicit feelings of exclusion. Results confirm the hypothesis of an involvement of the insular cortex as a common node of different functional networks, thus suggesting its potential role as a central mediator of cortical fc alterations, following modifications of GM. Also, the Rifaximin group displayed lower connectivity in slow and fast beta bands (15 and 25 Hz) during rest, and higher connectivity in theta (7 Hz) during the inclusion condition of the CBG, compared with controls. Altogether these results indicate a modulation of Rifaximin on frequency-specific functional connectivity that could involve cognitive flexibility and memory processing.

6.
JAMA Otolaryngol Head Neck Surg ; 147(4): 395-396, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33538784
7.
Cancer Cytopathol ; 2021 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-33595882

RESUMO

BACKGROUND: The diagnosis and management of salivary gland tumors in pediatric patients can be challenging. The utility of fine-needle aspiration (FNA) cytopathology and the performance of the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) in this age group have not been systematically assessed. The paucity of data has contributed to the controversial role of FNA cytopathology in the presurgical management of these patients. METHODS: The authors retrospectively analyzed 104 pediatric salivary gland FNAs (2000-2020). A correlation with the available histopathologic follow-up (n = 54) was performed. The distribution percentages, the risk of neoplasm (RON), and the risk of malignancy (ROM) were assessed for each category of the MSRSGC. RESULTS: The overall sensitivity, specificity, negative predictive value, and positive predictive value of pediatric salivary gland FNAs were 80%, 97%, and 92%, respectively. The RON values for the nondiagnostic, nonneoplastic, atypia of undetermined significance, benign neoplasm, salivary gland neoplasm of uncertain malignant potential, suspicious for malignancy, and malignant categories were 60%, 11%, 100%, 100%, 100%, 100%, and 100%, respectively, whereas the ROM values were 0%, 11%, 100%, 6%, 67%, 100%, and 100%, respectively. The percentage of nonneoplastic FNAs was greater in comparison with the adult population (52% vs 8%). All neoplasms in patients aged 0 to 10 years were malignant, whereas benign neoplasms occurred only in patients aged ≥11 years; this supported an inverse correlation between age and malignancy rate in salivary gland neoplasms. CONCLUSIONS: FNA cytopathology demonstrates excellent diagnostic performance in differentiating malignant and benign pediatric salivary gland lesions. The MSRSGC is a valuable tool for standardization of the reporting and preoperative risk stratification of these lesions.

8.
Am J Clin Pathol ; 2021 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-33609098

RESUMO

OBJECTIVES: Mucinous adenocarcinoma arising in unresected congenital pulmonary airway malformation (CPAM) is rare. Underlying driver mutations in addition to KRAS gain-of-function mutations in this setting and the long-term outcomes of these patients are unknown. METHODS: We report a case of metastatic mucinous adenocarcinoma harboring both KRAS and GNAS mutations arising in a type 1 CPAM of a 14-year-old male. A literature review was performed. RESULTS: Next-generation sequencing revealed identical KRAS (G12V) mutations in both the CPAM and metastatic adenocarcinoma and a missense mutation in the GNAS (R201C) gene in the metastatic adenocarcinoma only. Median survival was 23 and 4 years for patients with localized (no or limited spread within the same lobe of CPAM) and distant involvement (spread to any different lobe of CPAM) of mucinous cells, respectively (95% confidence interval, 23-23 and 1.5-22 years, respectively; P = .017). CONCLUSIONS: Mucinous cell proliferation associated with type 1 CPAM has exceptionally good long-term outcomes if confined within the same lobe of CPAM. A second oncogenic mutation in the GNAS gene may be necessary for progression to malignancy and distant spread.

9.
Neurotox Res ; 2021 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-33400180

RESUMO

Alzheimer's disease is an age-related neurodegenerative disease, associated with the presence of extracellular amyloid-ß (Aß) plaques and neurofibrillary tangles. Although the pathogenesis of AD remains unclear, the characteristic feature of AD was reported to be the buildup of Aß plaques. In this study, we extensively investigated the neuroprotective effects of 2-substituted 1,3-selenazole amide derivatives (CHF11) on Aß1-42 transgenic Caenorhabditis elegans CL4176. Results showed that worms fed with CHF11 exhibited remarkably reduced paralysis, decreased levels of toxic Aß oligomers and Aß plaque deposition, as well as less ROS production in comparison with the untreated worms. The effective concentrations of CHF11 were arranged in the descending order of 100 µM > 10 µM > 1 µM. Real-time PCR analysis showed that there was no significant difference in Aß expression between CHF11-administered group and the blank control group, suggesting that CHF11-induced reduction in toxic protein deposition may be regulated at the post-transcriptional level. In the meantime, the gene expressions of hsf-1 and its downstream target hsp-12.6 were significantly increased, indicating that CHF11 against Aß toxicity may involve in HSF-1 signaling pathway in worms. In conclusion, CHF11 exhibits a significant protective effect against ß-amyloid-induced toxicity in CL4176 by reducing ß-amyloid aggregation and ROS production, which may involve in HSF-1 and downstream target HSP-12.6 pathway.

10.
J Diabetes Res ; 2020: 6666403, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33299890

RESUMO

Aim: To evaluate the effect of an inhibitor of sodium-glucose cotransporter 2 (SGLT-2 inhibitor, dapagliflozin) on glycemic variability in type 2 diabetes mellitus (T2D) under insulin glargine combined with oral hypoglycemic drugs, using a continuous glucose monitoring system (CGMS). Methods: This prospective, self-controlled, single-center clinical trial recruited 36 patients with T2D under combined insulin glargine and oral hypoglycemic drugs. General clinical data were collected. Fasting blood glucose (FBG), postprandial blood glucose (PBG), glycosylated hemoglobin (HbA1c), and C-peptide levels were assessed before and four weeks of dapagliflozin (10 mg per day) treatment. Blood glucose was monitored for 72 hours before and after treatment using CGMS. Results: After treatment with dapagliflozin, FBG decreased from 6.74 ± 1.78 to 5.95 ± 1.13 mmol/L (p < 0.05); PBG decreased from 13.04 ± 2.99 to 10.92 ± 3.26 mmol/L (p < 0.05); HbA1c decreased from 7.37 ± 0.96% to 6.94 ± 0.80%. The proportion of patients with HbA1c < 7% increased from 27.8% to 58.3%, and the proportion of patients with HbA1c < 7% and without level 2 hypoglycemia increased from 27.8% to 55.6% (p < 0.05). CGMS data showed reduction of the 24 h MBG, MAGE, time-above-range (TAR, >10 mmol/L), high blood glucose index (HBGI), glucose management indicator (GMI), and incremental area under the curve of the glucose level more than 10 mmol/L (AUC > 10) and an increase of time-in-range (TIR, 3.9-10 mmol/L) with treatment. Homeostasis model assessment for pancreatic beta-cell function (HOMA-beta) increased significantly with treatment (p < 0.05), and fewer insulin doses were required after the treatment, without increasing in hypoglycemia and urinary tract infection. Further, a stratified analysis showed that patients with higher pretreatment HbA1c and waist-to-hip ratio (WHR) had greater improvement in glycemic control. Conclusion: Dapagliflozin may reduce blood glucose levels, ameliorate glycemic variability, and improve pancreatic beta-cell function in patients with T2D under insulin glargine combined with other oral hypoglycemic drugs, especially in those with poor glucose control and abdominal obesity.

11.
Artigo em Inglês | MEDLINE | ID: mdl-33258923

RESUMO

OBJECTIVES: We aimed to determine susceptibilities of Elizabethkingia spp. to 25 commonly tested and 8 novel antibiotics, and to compare the performance of different susceptibility testing methods. METHODS: Clinical isolates of Elizabethkingia spp., Chryseobacterium spp. and Flavobacterium spp. collected during 2002-18 (n = 210) in a nationwide surveillance programme in Taiwan were speciated by 16S rRNA sequencing. MICs were determined by broth microdilution. The broth microdilution results of 18 common antibiotics were compared with those obtained by the VITEK 2 automated system. RESULTS: Among the Elizabethkingia spp. identified (n = 108), Elizabethkingia anophelis was the most prevalent (n = 90), followed by Elizabethkingia meningoseptica (n = 7) and Elizabethkingia miricola cluster [E. miricola (n = 6), Elizabethkingia bruuniana (n = 3) and Elizabethkingia ursingii (n = 2)]. Most isolates were recovered from respiratory or blood specimens from hospitalized, elderly patients. PFGE showed two major and several minor E. anophelis clones. All isolates were resistant to nearly all the tested ß-lactams. Doxycycline, minocycline and trimethoprim/sulfamethoxazole inhibited >90% of Elizabethkingia spp. Rifampin inhibited E. meningoseptica (100%) and E. anophelis (81.1%). Fluoroquinolones and tigecycline were active against E. meningoseptica and E. miricola cluster isolates. Novel antibiotics, including imipenem/relebactam, meropenem/vaborbactam, ceftazidime/avibactam, cefepime/zidebactam, delafloxacin, eravacycline and omadacycline were ineffective but lascufloxacin inhibited half of Elizabethkingia spp. The very major discrepancy rates of VITEK 2 were >1.5% for ciprofloxacin, moxifloxacin and vancomycin. Major discrepancy rates were >3% for amikacin, tigecycline, piperacillin/tazobactam and trimethoprim/sulfamethoxazole. CONCLUSIONS: MDR, absence of standard interpretation criteria and poor intermethod concordance necessitate working guidelines to facilitate future research of emerging Elizabethkingia spp.

12.
Clin Transl Allergy ; 10(1): 50, 2020 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-33292509

RESUMO

BACKGROUND: Artemisia weed pollen allergy is important in the northern hemisphere. While over 350 species of this genus have been recorded, there has been no full investigation into whether different species may affect the allergen diagnosis and treatment. This study aimed to evaluate the variations in amino acid sequences and the content of major allergens, and how these affect specific IgE binding capacity in representative Artemisia species. METHODS: Six representative Artemisia species from China and Artemisia vulgaris from Europe were used to determine allergen amino acid sequences by transcriptome, gene sequencing and mass spectrometry of the purified allergen component proteins. Sandwich ELISAs were developed and applied for Art v 1, Art v 2 and Art v 3 allergen quantification in different species. Aqueous pollen extracts and purified allergen components were used to assess IgE binding by ELISA and ImmunoCAP with mugwort allergic patient serum pools and individual sera from five areas in China. RESULTS: The Art v 1 and Art v 2 homologous allergen sequences in the seven Artemisia species were highly conserved. Art v 3 type allergens in A. annua and A. sieversiana were more divergent compared to A. argyi and A. vulgaris. The allergen content of Art v 1 group in the seven extracts ranged from 3.4% to 7.1%, that of Art v 2 from 1.0% to 3.6%, and Art v 3 from 0.3% to 10.5%. The highest IgE binding potency for most Chinese Artemisia allergy patients was with A. annua pollen extract, followed by A. vulgaris and A. argyi, with A. sieversiana significantly lower. Natural Art v 1-3 isoallergens from different species have almost equivalent IgE binding capacity in Artemisia allergic patients from China. CONCLUSION AND CLINICAL RELEVANCE: There was high sequence similarity but different content of the three group allergens from different Artemisia species. Choice of Artemisia annua and A. argyi pollen source for diagnosis and immunotherapy is recommended in China.

13.
Br J Nurs ; 29(22): 1308-1310, 2020 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-33325297

RESUMO

Oesophageal bezoars are one of the many causes of nasogastric tube obstruction; however, they are extremely rare and, therefore, not often considered to be the cause of a blockage. A bezoar is a solid mass of indigestible material that accumulates in the digestive tract. After a blockage is identified, the nasogastric tube is usually removed and another one inserted. However, this can be dangerous and can easily cause tearing of the oesophageal mucosa, bleeding, and other serious complications. In this article, the authors present a case of nasogastric tube obstruction caused by oesophageal bezoars. After the nasogastric tube was replaced, the patient experienced two tears of the oesophageal mucosa. This article highlights the importance of the introduction of a procedure for nurses to follow in cases of nasogastric tube obstruction, bearing in mind the possibility of the presence of oesophageal bezoars. If necessary, a gastroscope should be used to ensure safe insertion of the nasogastric tube and prevent oesophageal mucosal tears.

14.
Langmuir ; 2020 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-33373522

RESUMO

Block copolymer microparticles with controllable morphology have drawn widespread attention owing to their promising applications in photonic materials, energy storage, and other areas. Hence, it is highly desired to achieve a controllable transformation of microparticle morphology. In this work, we report a simple method to shape the morphology of polystyrene-block-poly(dimethylsiloxane) (PS-b-PDMS) microparticles, by employing core-cross-linked polymeric nanoparticles (CNPs) as cosurfactants which are synthesized through cross-linking P4VP segment of PS-block-poly(4-vinylpyridine) (PS-b-P4VP). The addition of pH-responsive CNPs makes the shape of pH-inert PS-b-PDMS microparticles sensitive to pH value. The PS-b-PDMS microparticles transformed from elongated Janus pupa-like particles to onion-like particles by decreasing the pH value of the aqueous phase. The deformation mechanism is investigated by changing pH value, the weight fraction of CNPs, and surfactant property. This study provides a facile strategy to deform microparticles of pH-inert BCPs by tuning pH value, which is anticipated to be applicable to other non-pH-responsive BCP microparticles.

15.
Front Microbiol ; 11: 557404, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33193140

RESUMO

In Taiwan, the 7-valent pneumococcal conjugate vaccine (PCV7) was introduced in 2006 and a PCV13 national childhood catchup program was implemented in 2013. To delineate the trend of serotype distribution and antimicrobial susceptibility following vaccination programs, we investigated a total of 1845 Streptococcus pneumoniae isolates collected biennially between 2002 and 2018 over a 3-month period from 25 hospitals. The number of isolates collected over the years decreased significantly in all age groups, from a total of 320 isolates in 2002 (pre-PCV), to 196 in 2010 (post-PCV7/pre-PCV13), to 89 in 2018 (post-PCV13). Overall, PCV7/PCV13 serotypes comprised 66.9%/76.3%, 53.1%/78.1%, and 15.7%/31.5% of isolates in 2002, 2010, and 2018, respectively. The leading serotypes in the pre-PCV era were 23F, 19F, 6B, and 14, while serotype 19A predominated in the post-PCV7/pre-PCV13 era, but non-vaccine serotypes (NVT) 15A (18.0%) and 23A (15.7%) surpassed 19A (10.1%) to become the top two leading serotypes in 2018. All the major serotypes, including the emergent serotypes 15A and 23A, were multidrug-resistant with high rates of non-susceptibility to ß-lactam (except serotype 3) and several non-ß-lactam agents. PFGE and MLST revealed that while meropenem-susceptible serotype 15A-ST3058 isolates and a serotype 23A-ST338 clone existed in earlier years, rise and spread of meropenem-non-susceptible serotype 15A-ST63 and serotype 23A-ST166 clones occurred in recent years. We conclude that successive implementation of PCVs has led to a marked decrease in pneumococcal isolate burden, but the replacement by meropenem-non-susceptible NVT 15A and 23A highlights the need for continued local surveillance to track pneumococcal evolution in each region to help vaccine polyvalency decisions.

16.
Expert Rev Mol Diagn ; 20(10): 1051-1062, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33138648

RESUMO

OBJECTIVE: This meta-analysis aims to explore the diagnostic value and accuracy of circulating lncRNAs as biomarkers of digestive system tumors. METHODS: PubMed, Embase, Cochrane Library, and Web of science were searched for relevant articles that were published before April 2019, and a meta-analysis was conducted. RESULTS: 52 studies with 63 lncRNAs were discussed in the meta-analysis. The pooled sensitivity and specificity of diagnosis were 0.80 (95% CI: 0.79-0.81) and 0.76 (95% CI: 0.75-0.77), respectively. The pooled DOR (the diagnostic odds ratio) was 15.63 (95% CI: 12.77-19.12), and the overall AUC (the area under the curve) was 0.87. Besides, subgroup analyzes showed that the DOR and AUC of large sample sizes (>80), multiple lncRNAs, serum-based lncRNAs, and downregulation group were superior to those of small sample sizes (≤80), single lncRNA, plasma-based lncRNAs, and upregulation group, respectively. The current data also highlight that the diagnostic accuracy of circulating lncRNAs in the case of colorectal cancer was higher than gastric cancer, hepatocellular carcinoma, esophageal carcinoma, and pancreatic cancer. And there is no difference in the perspective of geographical regions. CONCLUSION: The circulating lncRNAs have high diagnostic value and accuracy in digestive system cancers and may serve as potential biomarkers.

17.
J Chromatogr A ; 1632: 461608, 2020 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-33086154

RESUMO

Based on theory of two-site model, a subtraction fitting method (SFM) is proposed to independently fit enantioselective adsorption sites and the nonselective adsorption sites on the surface of chiral stationary phases (CSP) based on polysaccharide derivatives. Compared with the direct fitting method, the method allows independent fitting the isotherm models of two types of adsorption sites. By the SFM, the adsorption data of methyl mandelate on the CSP based on cellulose tri-(3, 5-dimethylphenylcarbamate) was measured. The adsorption on enantioselective sites was well fitted with Langmuir model, and the adsorption on nonselective sites was well fitted with Tóth model or Langmuir-Freundlich model. The adsorption isotherms of the enantiomers of Corey PG-lactone diol on chiral stationary phase coated with different amounts of amylose tri-(3,5-dimethylphenylcarbamate) (Wchiral selector: Wsilica = 20 : 100, 30: 100 and 40: 100, respectively) were also studied. It was found that the saturated adsorption capacities of both sites increase with the increase of the chiral selector loading. The chiral stationary phase with low chiral selector loading (Wchiral selector: Wsilica = 20 : 100) has a high true separation factor (αtrue = 16.8) and the lowest apparent separation (αapp = 1.70) due to the large nonselective adsorption, which indicates that a chromatographic support with an inert surface is important for this type of CSP.


Assuntos
Modelos Teóricos , Temperatura , Adsorção , Amilose/química , Celulose/química , Lactonas/química , Ácidos Mandélicos/química , Dióxido de Silício , Estereoisomerismo
18.
Biomed Pharmacother ; 132: 110765, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33120237

RESUMO

AIM: Hyperuricemia (HUA) is a metabolic disease caused by the overproduction or underexcretion of uric acid (UA). Our previous study found that treatment with Dendrobium officinalis six nostrum (DOS) led to a significant reduction in serum UA (SUA) by inhibiting UA production and promoting UA excretion in a rat model of HUA induced by potassium oxonate (PO) and high-fat sorghum feed. In this study, we aimed to further investigate the effects of DOS on UA excretion by the kidney and intestine to explore whether DOS protects against histopathological changes, and to elucidate its possible mechanisms of action in a lipid emulsion (LE)-induced rat model of HUA. METHODS: The main chemical constituents of DOS were determined to be acteoside and astilbin by high-performance liquid chromatography (HPLC). Three different doses of DOS (3.3, 6.6, and 13.2 g/kg/day) were given to rats daily after induction of HUA by oral administration of LE for 8 weeks. The levels of creatinine (Cr) in serum and urine and UA in serum, urine, and feces were measured by an automatic biochemical analyzer. The expression of TLR4, NF-κB and urate transport-related transporters (URAT1, ABCG2, and PDZK1) in kidney was measured by Western blot (WB). Intestinal urate transporters (ABCG2 and GLUT9) expression was assayed by IHC and WB. Serum LPS and renal inflammatory factors (IL-6, IL-8 and TNF-α) levels were measured using enzyme-linked immunosorbent assay (ELISA) kits. Hematoxylin and eosin (H&E) staining was used to assess renal histological changes. RESULTS: DOS treatment significantly reduced the SUA and SCr levels by increasing urine volume, 24 h urine uric acid (UUA), fecal UA (FUA), urine creatinine (UCr), and fractional excretion of UA (FEUA) levels in hyperuricemic rats. Moreover, DOS effectively regulated URAT1, PDZK1, and ABCG2 protein levels in the kidney, as well as restored protein levels of GLUT9 and ABCG2 in the intestine. DOS markedly reduced serum LPS anddown-regulated renal TLR4 and NF-κB protein levels to suppress IL-6, IL-8, and TNF-α secretion. It also improved renal inflammation in hyperuricemic rats. In addition, DOS attenuated histopathological changes in the kidneys of LE-induced rats. HPLC analysis showed levels of acteoside and astilbin of 1.39 mg/g and 0.72 mg/g in DOS, respectively. CONCLUSION: DOS has anti-hyperuricemic and anti-inflammatory effects in a rat model of HUA. The molecular mechanism appears to involve the regulation of urate transport-related transporters including renal ABCG2, URAT1, and PDZK1, and intestinal GLUT9 and ABCG2, as well as the inhibition of the LPS/TLR4/NF-κB signaling to reduce IL-6, IL-8, and TNF-α secretion in hyperuricemic rats.

19.
Brain Imaging Behav ; 2020 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-32909105

RESUMO

The purpose of this study was to investigate cerebral blood flow (CBF) changes in hemodialysis patients with arterial spin labeling (ASL) and to correlate these changes with clinical risk factors and neurocognitive function. Thirty-two hemodialysis patients and 35 age-, sex-, and education-matched healthy controls (HCs) were recruited in this prospective study. The Mini-Mental State Examination (MMSE) was performed to evaluate neurocognitive function. Pulsed ASL was performed to measure CBF. Two independent sample t-test was used to explore the CBF difference between the patients and HCs. Multiple stepwise regression was used to investigate the risk factors for CBF in patients. Correlation analysis was used to explore the relationship between the MMSE scores and CBF changes with and without adjusting for anemia status. Compared to HCs, the hemodialysis patients showed significantly increased CBF in some neurocognition-related cerebral regions (all P < 0.001, Bonferroni corrected). Increased CBF in the right opercular and triangular part of the inferior frontal gyrus correlated with the poorer MMSE scores (r = -0.502, P = 0.004; r = -0.423, P = 0.018, FDR corrected) and these correlations still remained after adjusting for anemia status (r = -0.516, P = 0.005; r = -0.439, P = 0.019, FDR corrected). The increased dialysis duration, and decreased hemoglobin, hematocrit, and serum phosphorus were predictive risk factors for increased CBF (P < 0.05). In conclusion, long-term hemodialysis patients had increased CBF, which correlated with neurocognitive impairment, and after adjusting for the effect of anemia, the correlation still remained.

20.
Am J Clin Pathol ; 2020 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-32915192

RESUMO

OBJECTIVES: We aimed to identify potential laboratory causes of suboptimal liver biopsy quality and sought to implement corresponding measures to improve biopsy adequacy. METHODS: We prospectively measured the number and size of tissue fragments and the amount of portal tracts in 200 consecutive pediatric medical liver biopsies before and after quality improvement processes were initiated. RESULTS: We identified laboratory-related tissue fragmentation as a significant cause of low biopsy adequacy. The principal approaches to reduce fragmentation included establishment of multistep monitoring of tissue integrity, adjustment of specimen-processing conditions, and laboratory staff education and awareness. These adjustments collectively led to lower overall tissue fragmentation (decreasing from 59% to 24%, P < .01) and higher biopsy adequacy rates (increasing from 32% to 56%, P < .01). The number of evaluable portal tracts increased from 4.4 to 5.7 portal tracts per centimeter of core biopsy tissue (P < .01). CONCLUSIONS: We demonstrated a sustainable improvement in the overall quality of pediatric needle core liver biopsies by reducing tissue fragmentation. Effective laboratory adjustments included monitoring of tissue integrity, modifications of processing conditions, and laboratory staff education.

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