Macromolecular crowding sensing during osmotic stress in plants.

Osmotic stress conditions occur at multiple stages of plant life. Changes in water availability caused by osmotic stress induce alterations in the mechanical properties of the plasma membrane, its interaction with the cell wall, and the concentration of macromolecules in the cytoplasm. We summarize the reported players involved in the sensing mechanisms of osmotic stress in plants. We discuss how changes in macromolecular crowding are perceived intracellularly by intrinsically disordered regions (IDRs) in proteins. Finally, we review methods for dynamically monitoring macromolecular crowding in living cells and discuss why their implementation is required for the discovery of new plant osmosensors. Elucidating the osmosensing mechanisms will be essential for designing strategies to improve plant productivity in the face of climate change.

Using NIR irradiation and magnetic bismuth ferrite microparticles to accelerate the removal of polystyrene microparticles from the drinking water.

Magnetic bismuth ferrite (BiFO) microparticles were employed for the first time for the removal of polystyrene (PS) nano/microplastics from the drinking water. BiFO is formed by porous agglomerates with sizes of 5-11 µm, while the PS nano/microparticles have sizes in the range of 70-11000 nm. X-ray diffraction studies demonstrated that the BiFO microparticles are composed of BiFeO3/Bi25FeO40 (the content of Bi25FeO40 is ≈ 8.6%). Drinking water was contaminated with PS nano/microparticles (1 g L-1) and BiFO microparticles were also added to the contaminated water. Later, the mixture of PS-particles + BiFO was irradiated with NIR light (980 nm). Consequently, PS nano/microparticles melted on the BiFO microparticles due to the excessive heating on their surface. At the same time, the NIR (near infrared) light generated oxidizing agents (∙OH and h+), which degraded the by-products formed during the photocatalytic degradation of PS nano/microparticles. Subsequently, the NIR irradiation was stopped, and a Neodymium magnet was utilized to separate the BiFO microparticles from the water. This last procedure also permitted the removal of PS nano/microparticles by physical adsorption. Zeta potential measurements demonstrated that the BiFO surface was positively charged, allowing the removal of the negatively charged PS nano/microparticles by electrostatic attraction. The combination of the photocatalytic process and the physical adsorption permitted a complete removal of PS nano/microparticles after only 90 min as well as a high mineralization of by-products (≈95.5% as confirmed by the total organic carbon measurements). We estimate that ≈23.6% of the PS nano/microparticles were eliminated by photocatalysis and the rest of PS particles (≈76.4%) by physical adsorption. An outstanding adsorption capacity of 195.5 mg g-1 was obtained after the magnetic separation of the BiFO microparticles from the water. Hence, the results of this research demonstrated that using photocatalysis + physical-adsorption is a feasible strategy to quickly remove microplastic contaminants from the water.

Molecular mechanisms underlying responses of the Antarctic coral Malacobelemnon daytoni to ocean acidification.

Benthic organisms of the Southern Ocean are particularly vulnerable to ocean acidification (OA), as they inhabit cold waters where calcite-aragonite saturation states are naturally low. OA most strongly affects animals with calcium carbonate skeletons or shells, such as corals and mollusks. We exposed the abundant cold-water coral Malacobelemnon daytoni from an Antarctic fjord to low pH seawater (LpH) (7.68 ± 0.17) to test its physiological responses to OA, at the level of gene expression (RT-PCR) and enzyme activity. Corals were exposed in short- (3 days) and long-term (54 days) experiments to two pCO2 conditions (ambient and elevated pCO2 equaling RCP 8.5, IPCC 2019, approximately 372.53 and 956.78 µatm, respectively). Of the eleven genes studied through RT-PCR, six were significantly upregulated compared with control in the short-term in the LpH condition, including the antioxidant enzyme superoxide dismutase (SOD), Heat Shock Protein 70 (HSP70), Toll-like receptor (TLR), galaxin and ferritin. After long-term exposure to low pH conditions, RT-PCR analysis showed seven genes were upregulated. These include the mannose-binding C-Lectin and HSP90. Also, the expression of TLR and galaxin, among others, continued to be upregulated after long-term exposure to LpH. Expression of carbonic anhydrase (CA), a key enzyme involved in calcification, was also significantly upregulated after long-term exposure. Our results indicated that, after two months, M. daytoni is not acclimatized to this experimental LpH condition. Gene expression profiles revealed molecular impacts that were not evident at the enzyme activity level. Consequently, understanding the molecular mechanisms behind the physiological processes in the response of a coral to LpH is critical to understanding the ability of polar species to cope with future environmental changes. Approaches integrating molecular tools into Antarctic ecological and/or conservation research make an essential contribution given the current ongoing OA processes.

14-3-3ε protein-immobilized PCL-HA electrospun scaffolds with enhanced osteogenicity.

Adipose-derived mesenchymal stem cells (ASCs) accelerate the osteointegration of bone grafts and improve the efficiency in the formation of uniform bone tissue, providing a practical and clinically attractive approach in bone tissue regeneration. In this work, the effect of nanofibrous biomimetic matrices composed of poly(ε-caprolactone) (PCL), nanometric hydroxyapatite (nHA) particles and 14-3-3 protein isoform epsilon on the initial stages of human ASCs (hASCs) osteogenic differentiation was investigated. The cells were characterized by flow cytometry and induction to differentiation to adipogenic and osteogenic lineages. The isolated hASCs were induced to differentiate to osteoblasts over all scaffolds, and adhesion and viability of the hASCs were found to be similar. However, the activity of alkaline phosphatase (ALP) as early osteogenic marker in the PCL-nHA/protein scaffold was four times higher than in PCL-nHA and more than five times than the measured in neat PCL.

Plasticity in sunflower leaf and cell growth under high salinity.

A group of sunflower lines that exhibit a range of leaf Na(+) concentrations under high salinity was used to explore whether the responses to the osmotic and ionic components of salinity can be distinguished in leaf expansion kinetics analysis. It was expected that at the initial stages of the salt treatment, leaf expansion kinetics changes would be dominated by responses to the osmotic component of salinity, and that later on, ion inclusion would impose further kinetics changes. It was also expected that differential leaf Na(+) accumulation would be reflected in specific changes in cell division and expansion rates. Plants of four sunflower lines were gradually treated with a relatively high (130 mm NaCl) salt treatment. Leaf expansion kinetics curves were compared in leaves that were formed before, during and after the initiation of the salt treatment. Leaf areas were smaller in salt-treated plants, but the analysis of growth curves did not reveal differences that could be attributed to differential Na(+) accumulation, since similar changes in leaf expansion kinetics were observed in lines with different magnitudes of salt accumulation. Nevertheless, in a high leaf Na(+) -including line, cell divisions were affected earlier, resulting in leaves with proportionally fewer cells than in a Na(+) -excluding line. A distinct change in leaf epidermal pavement shape caused by salinity is reported for the first time. Mature pavement cells in leaves of control plants exhibited typical lobed, jigsaw-puzzle shape, whereas in treated plants, they tended to retain closer-to-circular shapes and a lower number of lobes.

Human papillomavirus infection in cyclosporin-induced gingival overgrowth in renal allograft recipients.

BACKGROUND: Host immunity plays an important role in the development of human papillomavirus (HPV)-associated disease. The HPV infection in oral cyclosporin-induced gingival overgrowth in renal transplant recipients has not been investigated previously. The aim of this study was to establish the HPV infection of cyclosporin-induced gingival hyperplasia in renal transplant recipients through morphological changes and use of the in situ hybridization technique. METHODS: We examined 13 renal transplant recipient biopsies with gingival overgrowth lesions and 4 healthy mucosa samples of these patients. The histopathological diagnoses were established on the basis of widely accepted criteria, and the pathologist was not aware of the HPV result. An in situ molecular hybridization was carried out under low stringent conditions to detect HPV species with mixed biotin-labeled probes of HPV 6 and HPV 11, and under high stringent conditions with HPV 6, HPV 11, HPV 16, and HPV 18 probes for HPV typing. RESULTS: The HPV prevalence among the 13 samples studied was 92.31% (12/13), of which 4 tested positive for HPV 6-11 and 1 for HPV 16. The 4 biopsies of normal mucosa from gingival overgrowth patients were also reactive for HPV DNA. In 11/12 (91.7%) HPV-positive cases, koilocytotic atypia was found. CONCLUSIONS: The suppression of T-cell function by cyclosporin therapy can result in an increase of HPV infection, adding to the proliferative activity of cyclosporin in the oral mucosa.

Loss of maternally derived human herpesvirus-6 immunity and natural infection in Argentinian infants.

BACKGROUND: Human herpesvirus-6 (HHV-6) infection is widespread throughout the world. No data are available in Argentina about the loss of maternally derived HHV-6 immunity and natural infection in infants. METHODS: A population of 100 pregnant women and 407 children between 1 and 15 months of age were assayed by indirect immunofluorescence to detect and quantify specific IgG anti-human herpesvirus-6 (anti-HHV-6) antibodies in Córdoba City, Argentina. RESULTS: There was no significant difference in the positive rate between infants aged 1 to 9 months (range, 43.6 35.5%) and pregnant women (37%). Seropositive ratio dropped in the 10-month group (23.33% seropositive) and rose sharply in the 11-month group (38.89%), 12-month (60.61%), and 13- to 15-month group (63.46%). The geometric mean titer (GMT) for infants in the 12 to 15 months age group (23.4 41.64) was significantly higher than the GMT for infants 10 months of age (11.04) (P < 0.05 with the Tukey-HSD test). CONCLUSIONS: This study shows a significant association between loss of passive HHV-6 antibody and age among infants. The results support evidence that HHV-6 enters the susceptible population at 11 months, leading to a high prevalence of antibodies in children between 13 and 15 months of age.

Quantification of fecal neutrophils by MPO determination (myeloperoxidase) in patients with invasive diarrhea. Cuantificación de neutrofilos fecales mediante la determinación de MPO (Mieloperoxidasa) en pacientes con diarrea invasiva.

Myeloperoxidase (MPO), a specific polymorphonuclear leukocyte enzyme, has been used previously to quantify the number of neutrophils in tissue. MPO activity was found to be linearly related to the number of neutrophil cells. In an attempt to use this method in leukocytes measuring in stool, fecal MPO was solubilized with hexadecyltrimethylammonium bromide and the MPO activity was measured by a dianisidine-H2O2 assay. Stools from 10 normal subjects and 39 patients with diarrhea produced by enteropathogenic bacteria were examined for leukocytes by MPO activity as well as microscopically using methylene blue stain, MPO activity was positive in 36 patients (92%) and leukocytes were present by microscopic observation in 30 (77%). Fecal leukocytes were not found in healthy controls and the MPO activity was undectable. Stool MPO activity had a range of from 1.6 to 2,830.0 x 10(3) UMPO per gram of feces (median 460.0). The number of neutrophils obtained through MPO activity had a range of 6.0 to 13,216.0/ mm3 (median 1,261.0). Fecal MPO activity is a simple biochemical assay for the detection and quantification of fecal leukocytes.

Conversion from azathioprine [correction of azathioprina] to mycophenolate mofetil in pediatric renal transplant recipients with chronic rejection.

BACKGROUND: Chronic rejection is the leading cause of graft failure. Both nonimmunological and immunological mechanisms contribute to this pathology. METHODS: We studied changes in kidney function, mixed lymphocyte culture, cell-mediated lympholysis, serum HLA class I antigens, cytotoxic antibodies, and lymphocyte population before and after 6 months of follow-up in 22 pediatric renal transplanted patients. The immunosuppressive protocol used was: cyclosporine, azathioprine, and corticosteroids. Eight patients demonstrated chronic graft rejection (by biopsy), group I; and eight patients had no clinical evidence of chronic and/or acute rejection, group II. Substitution of mycophenolate mofetil (MMF) (600 mg/m2 bid for azathioprine was done in patients of groups I and II. Another six patients with chronic rejection, did not receive MMF, group III. RESULTS: Creatinine clearance increased in group I (44+/-5 vs. 51.1+/- ml/min/1.73 m2, P<0.03) but it decreased in group III (30+/-3 vs. 25+/-2, P<0.01). Urinary protein excretion decreased only in group I (0.3+/-0.03 to 0.06+/-0.03 g/24 hr, P<0.03). During MMF therapy antidonor mixed lymphocyte culture decreased 62 and 70% (P<0.05) in group I and II. Cell-mediated lympholysis against lymphocyte of the donor decreased 65% (P<0.05) in group I. Cell-mediated lympholysis toward control cells decreased 54% (P<0.01) in group II. Serum HLA class I antigens, only decreased from 0.7+/-0.1 to 0.5+/-0.1 microl/ml, P<0.05, in group I. CD19+ decreased from 7.9+/-1.1 to 5.6+/-0.8%, P<0.05, and 7.8+/-1.2 to 5.5+/-0.9%, P<0.05, in groups I and II, respectively. CD16+ increased from 5.7+/-1.1 to 8.6+/-1.3 (P<0.05) only in group I. CONCLUSIONS: Our data suggest that substituting MMF for azathioprine therapy leads to an improvement in the immunosuppression and renal function in children with on-going chronic rejection.

Antibacterial activity of some medicinal plants from San Juan, Argentina.

The antibacterial activities and preliminary phytochemical screening of 13 plants used as folk medicine in San Juan, Argentina, are reported.

Biologically active alkaloids and a free radical scavenger from Prosopis species.

The biological activity of extracts from the aerial parts of five Argentinian Prosopis species and the exudate of P. flexuosa were assessed for DNA binding, beta-glucosidase inhibition and free radical scavenging effect using the DPPH decoloration assay. DNA binding effect was found mainly in the basic fraction. The alkaloids tryptamine as well as piperidine and phenethylamine derivatives were isolated from the basic extracts. At 0.50 mg/ml, DNA binding activities ranged from 28% for tryptamine to 0-27% for the phenethylamine and 47-54% for the piperidine derivatives. Tryptamine and 2-beta-methyl-3-beta-hydroxy-6-beta-piperidinedodecanol showed a moderate inhibition (27-32%) of the enzyme beta-glucosidase at 100 microg/ml. The exudate of P. flexuosa displayed a strong free radical scavenger effect in the DPPH decoloration assay. The main active constituent was identified as catechin.

Quantification of fecal neutrophils by MPO determination (myeloperoxidase) in patients with invasive diarrhea. Cuantificación de neutrofilos fecales mediante la determinación de MPO (Mieloperoxidasa) en pacientes con diarrea invasiva

Myeloperoxidase (MPO), a specific polymorphonuclear leukocyte enzyme, has been used previously to quantify the number of neutrophils in tissue. MPO activity was found to be linearly related to the number of neutrophil cells. In an attempt to use this method in leukocytes measuring in stool, fecal MPO was solubilized with hexadecyltrimethylammonium bromide and the MPO activity was measured by a dianisidine-H2O2 assay. Stools from 10 normal subjects and 39 patients with diarrhea produced by enteropathogenic bacteria were examined for leukocytes by MPO activity as well as microscopically using methylene blue stain, MPO activity was positive in 36 patients (92

) and leukocytes were present by microscopic observation in 30 (77

). Fecal leukocytes were not found in healthy controls and the MPO activity was undectable. Stool MPO activity had a range of from 1.6 to 2,830.0 x 10(3) UMPO per gram of feces (median 460.0). The number of neutrophils obtained through MPO activity had a range of 6.0 to 13,216.0/ mm3 (median 1,261.0). Fecal MPO activity is a simple biochemical assay for the detection and quantification of fecal leukocytes.

Cuantificación de neutrófilos fecales mediante la determinacián de MPO (Mieloperoxidasa) en pacientes con diarrea invasiva / Quantify of fecal neutrophils by MPO (myeloperoxidase) determination in patients with invasive diarrhea

La mieloperoxidasa (MPO) es una enzima especifíca de los polimorfonucleares neutrófilos, la cual ha sido previamente usada para cuantificar elmnúmero de neutrófilos en tejidos, desde que su actividad se correlaciona linealmente con el número de neutrófilos. Con el objetivo de demostrar la presencia y realizar la cuantificación de leucocitos en materia fecal la MPO se disolvió en Bromuro de hexadeciltrimetilamonio y la actividad fue medida usando un ensayo de H2O2O-dianosid-ina. Se midió la actividad de MPO en 39 pacientes con diarrea producida por bacterias enteropatógenas y en 10 sujetos control. La presencia de leucocitos fue también determinada mediante la observación microscópica usando azul de metileno. La actividad de MPO fue positiva en 36 (92 por ciento) de los pacientes y la observació microscópica resultó positiva en 30 (77 por ciento). En los sujetos control la actividad de MPO fue indetectable y no se encontraron leucocitos en material fecal. En los pacientes la actividad de MPO en materia fecal tuvo un recuento de 1.6 a 2830 x 10(3) UMPO por gramo de heces (mediana: 46.0). El número de neutrófilos obtenido a través de la actividad de MPO tuvo un recuento de 6 a 13216.0 x mm(3) (mediana: 1261.0), la actividad fecal de MPO es una determinación bioquímica simple para la detección y cuantificación de leucocitos en materia fecal.

Cuantificación de neutrófilos fecales mediante la determinacián de MPO (Mieloperoxidasa) en pacientes con diarrea invasiva / Quantify of fecal neutrophils by MPO (myeloperoxidase) determination in patients with invasive diarrhea

La mieloperoxidasa (MPO) es una enzima especifíca de los polimorfonucleares neutrófilos, la cual ha sido previamente usada para cuantificar elmnúmero de neutrófilos en tejidos, desde que su actividad se correlaciona linealmente con el número de neutrófilos. Con el objetivo de demostrar la presencia y realizar la cuantificación de leucocitos en materia fecal la MPO se disolvió en Bromuro de hexadeciltrimetilamonio y la actividad fue medida usando un ensayo de H2O2O-dianosid-ina. Se midió la actividad de MPO en 39 pacientes con diarrea producida por bacterias enteropatógenas y en 10 sujetos control. La presencia de leucocitos fue también determinada mediante la observación microscópica usando azul de metileno. La actividad de MPO fue positiva en 36 (92 por ciento) de los pacientes y la observació microscópica resultó positiva en 30 (77 por ciento). En los sujetos control la actividad de MPO fue indetectable y no se encontraron leucocitos en material fecal. En los pacientes la actividad de MPO en materia fecal tuvo un recuento de 1.6 a 2830 x 10(3) UMPO por gramo de heces (mediana: 46.0). El número de neutrófilos obtenido a través de la actividad de MPO tuvo un recuento de 6 a 13216.0 x mm(3) (mediana: 1261.0), la actividad fecal de MPO es una determinación bioquímica simple para la detección y cuantificación de leucocitos en materia fecal. (Au)

Quantification of fecal neutrophils by MPO determination (myeloperoxidase) in patients with invasive diarrhea. Cuantificación de neutrofilos fecales mediante la determinación de MPO (Mieloperoxidasa) en pacientes con diarrea invasiva.

Myeloperoxidase (MPO), a specific polymorphonuclear leukocyte enzyme, has been used previously to quantify the number of neutrophils in tissue. MPO activity was found to be linearly related to the number of neutrophil cells. In an attempt to use this method in leukocytes measuring in stool, fecal MPO was solubilized with hexadecyltrimethylammonium bromide and the MPO activity was measured by a dianisidine-H2O2 assay. Stools from 10 normal subjects and 39 patients with diarrhea produced by enteropathogenic bacteria were examined for leukocytes by MPO activity as well as microscopically using methylene blue stain, MPO activity was positive in 36 patients (92

) and leukocytes were present by microscopic observation in 30 (77

). Fecal leukocytes were not found in healthy controls and the MPO activity was undectable. Stool MPO activity had a range of from 1.6 to 2,830.0 x 10(3) UMPO per gram of feces (median 460.0). The number of neutrophils obtained through MPO activity had a range of 6.0 to 13,216.0/ mm3 (median 1,261.0). Fecal MPO activity is a simple biochemical assay for the detection and quantification of fecal leukocytes.

Identification of mRNA-binding proteins during development: characterization of Bufo arenarum cellular nucleic acid binding protein.

Ultraviolet irradiation was used to covalently cross-link poly(A)+RNA and associated proteins in eggs and embryos of the toad Bufo arenarum. Four major proteins with apparent sizes of 60, 57, 45 and 30-24 kDa were identified. It was observed that the same mRNA-binding proteins were isolated from eggs to gastrula and neural stages of development. The 30 kDa polypeptide, p30, appeared as the main ultraviolet (UV) cross-linked protein in the developmental stages analyzed. By means of polyclonal antibodies, it was determined that this polypeptide has a cytoplasmic localization and it was detected in liver, eggs and embryos. The presence of p30 was also analyzed by western blot during oogenesis and development. The 30 kDa polypeptide was present in all stages analyzed but it could not be detected in stages I-II of oogenesis. At the neural stage, the relative amount of p30 began to decrease, reaching its lowest levels after stages 26-30 (tail-bud in Bufo arenarum). On the basis of purification, immunoprecipitation and western blot assays the 30 kDa protein was identified as the Bufo arenarum cellular nucleic acid binding protein.

Atovaquone-proguanil compared with chloroquine and chloroquine-sulfadoxine-pyrimethamine for treatment of acute Plasmodium falciparum malaria in the Philippines.

This randomized, open-label clinical trial compared a fixed-dose combination of atovaquone and proguanil (n=55) with chloroquine (n=23) or a combination of chloroquine, sulfadoxine, and pyrimethamine (n=32) for treatment of acute falciparum malaria in the Philippines. Patients were hospitalized for 28 days to ensure medication compliance and prevent reinfection. Atovaquone-proguanil produced a significantly higher cure rate (100%) compared with that for chloroquine (30.4%; P<.0001) or chloroquine-sulfadoxine-pyrimethamine (87.5%; P<.05). Treatments did not differ significantly with respect to parasite clearance time (mean: 46.7 h for atovaquone-proguanil, 60.0 h for chloroquine, and 42.8 h for chloroquine-sulfadoxine-pyrimethamine) or fever clearance time (mean, 38.8, 46.8, and 34.5 h, respectively). Adverse events were typical of malaria symptoms; the most frequently reported events were vomiting (18% for atovaquone-proguanil, 17% for chloroquine, and 9% for chloroquine-sulfadoxine-pyrimethamine), abdominal pain (15%, 17%, and 3%, respectively), anorexia (11%, 13%, and 0%, respectively), and headache (6%, 17%, and 3%, respectively). Atovaquone-proguanil was well tolerated and more effective than chloroquine or chloroquine-sulfadoxine-pyrimethamine for treatment of multidrug-resistant falciparum malaria in the Philippines.

[Human papillomavirus detection in oral cancer lesions in the city of Córdoba]. / Detección del virus papiloma humano en lesiones cancerosas orales en la ciudad de Córdoba.

Oral cancer is a process that involves different etiological factors and mechanisms in the light of current view of viral cocarcinogenesis. Evidence from histology and DNA hybridization studies suggests that HPV is engaged in oral carcinogenesis. The Pathology Laboratory of the Dentistry School, National University of Córdoba, admits approximately 20% of all patients with cancerous lesions in this city. In the January 1992-December 1997 lapse, we examined 1950 biopsies with oral lesions, 4.77% (93/1950) of which were malignant neoplasms, 79.57% (74/93) were oral carcinomas. Thirty-three oral carcinomas (44.6%; 33/74) were selected at random and included in this study, 33 cells smears of normal oral mucosa of controls individuals were included. They were analyzed by conventional light microscopy and an in situ hybridization technique for the detection of HPV. Data were analyzed with chi square test. The prevalence of HPV among the 33 cancer samples studied was 27.27%, 9/33 tested positive for HPV in low stringent conditions. Only one was positive in high stringent condition for HPV16, a verrugous carcinoma. No HPV-DNA was detected in cells smears of controls. Among the HPV positive, 3/9 (33.33%) were squamous carcinomas and 5/9 (55.56%) were verrugous carcinomas. Only one was a melanoma. Verrugous carcinoma was the carcinoma most associated with the HPV infection (x2 = 20.5; 95% level of confidence). This would indicate a major role of HPV in the pathogenesis of verrucous carcinomas. The viral prevalence found in cancerous lesions reinforces the concept of heterogenic natures of oral cancer. HPV is a circumstance that increase the probability of malignancy, and when reducing, diminish the frequency of cancer.