Expression of pancreatic endocrine markers by mesenchymal stem cells from human adipose tissue

Mesenchymal stem cells (MSCs) from human adipose tissue have a great potential for use in cell therapy due to their ease of isolation, expansion, and differentiation, besides the relative acceptance from the ethical point of view. Our intention was to isolate and promote in vitro expansion and differentiation of MSCs from human adipose tissue into cells with a pancreatic endocrine phenotype. Human adipose tissue obtained from patients undergoing abdominal dermolipectomy was digested with type I collagenase. MSCs isolated by plastic adherence and characterized by cytochemistry and FACS were expanded in vitro. MSC differentiation into an endocrine phenotype was induced over 2 to 4 months with high glucose (25 mmol/L) media containing nicotinamide, exendin-4, and 2-mercaptoethanol. Insulin and glucagon expressions were analyzed by immunofluorescence. Cells isolated from human adipose tissue and expanded in vitro expressed MSC markers as confirmed by FACS and cytochemistry. Insulin but not glucagon production by differentiated cells was demonstrated by immunofluorescence. MSCs isolated from human adipose tissue were induced to differentiate in vitro into an endocrine phenotype that expressed insulin.

Nuclear lipid droplets: a novel nuclear domain

We investigated nuclear neutral-lipid (NL) composition and organization, as NL may represent an alternative source for providing fatty acids and cholesterol (C) to membranes, signaling paths, and transcription factors in the nucleus. We show here that nuclear NL were organized into nonpolar domains in the form of nuclear-lipid droplets (nLD). By fluorescent confocal microscopy, representative nLD were observed in situ within the nuclei of rat hepatocytes in vivo and HepG2 cells, maintained under standard conditions in culture, and within nuclei isolated from rat liver. nLD were resistant to Triton X-100 and became stained with Sudan Red, OsO4, and BODIPY493/503. nLD and control cytosolic-lipid droplets (cLD) were isolated from rat-liver nuclei and from homogenates, respectively, by sucrose-gradient sedimentation. Lipids were extracted, separated by thin-layer chromatography, and quantified. nLD were composed of 37% lipids and 63% proteins. The nLD lipid composition was as follows: 19% triacylglycerols (TAG), 39% cholesteryl esters, 27% C, and 15% polar lipids; whereas the cLD composition contained different proportions of these same lipid classes, in particular 91% TAG. The TAG fatty acids from both lipid droplets were enriched in oleic, linoleic, and palmitic acids. The TAG from the nLD corresponded to a small pool, whereas the TAG from the cLD constituted the main cellular pool (at about 100% yield from the total homogenate). In conclusion, nLD are a domain within the nucleus where NL are stored and organized and may be involved in nuclear lipid homeostasis.

First Report of Pestalotiopsis clavispora Causing Dieback on Blueberry in Uruguay

During the last 10 years, blueberry (Vaccinium corymbosum) production in Uruguay has increased to more than 850 ha. From 2005, symptoms of dieback characterized by the death of twigs and branches have been frequently observed in blueberry plants cv. O'Neal in orchards located in Uruguay. Symptomatic 4-year-old plants (cv. O'Neal) were collected and small pieces of necrotic tissues were surface disinfected and plated onto potato dextrose agar (PDA) with 0.2 g liter^-1 of streptomycin sulfate. Plates were incubated at 25°C in the dark. All affected tissues consistently developed colonies with white and cottony mycelium, turning slightly yellow after 7 to 10 days. Black acervuli distributed in concentric circles were observed after 10 days. Conidia were fusiform, straight, and had five cells. Basal and apical cells were colorless while the three median cells were dark brown. Conidia (n = 50) had an average of 22.1 (16.5 to 28.2) × 6.6 (5.6 to 7.7) μm. All conidia had one basal appendage of 6.1 (3.9 to 14.3) μm and two to four (usually three) apical appendages of 22.8 (17.4 to 42.9) μm. According to colony and conidia morphology, the isolates were initially identified as Pestalotiopsis clavispora (G.F. Atk.) Steyaert (1). To identify, the internal transcribed spacers (ITS1, 5.8S, ITS2) region of rDNA of a representative isolate (Ara-1) was amplified with ITS1/ITS4 primers (4), sequenced, and compared with those deposited in GenBank. The isolate Ara-1 (Accession No. JQ008944) had 100% sequence identity with P. clavispora (Accession Nos. FJ517545 and EU342214). To confirm pathogenicity, isolate Ara-1 was inoculated onto asymptomatic 1-year-old blueberry plants (cv. O'Neal). Mycelial plugs (4 mm in diameter) from an actively growing colony on PDA were applied to same-size bark wounds made with a cork borer in the center of the stems previously disinfected with 70% ethanol and covered with Parafilm. Control plants were inoculated with sterile PDA plugs. Inoculated plants (five per treatment) were randomly distributed in a greenhouse and watered as needed. After 2 weeks, all stems inoculated with P. clavispora showed brown necrotic lesions 2 to 3 cm in length and 1 to 2 mm deep. White mycelium was observed over lesions. Control plants remained symptomless. The pathogen was reisolated from all necrotic lesions, thus fulfilling Koch's postulates. P. clavispora has been reported as associated with blueberry in Hawaii (3) and Chile (2). To our knowledge, this is the first report of P. clavispora causing dieback disease on blueberry in Uruguay. References: (1) E. F. Guba, Monograph of Pestalotia and Monocheatia. Harvard University Press, Cambridge, MA, 1961. (2) J. G. Espinoza et al. Plant Dis. 92:1407, 2008. (3) L. M. Keith et al. Plant Dis. 90:16, 2006. (4) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, 1990.

Bio-inspired porous SiC ceramics loaded with vancomycin for preventing MRSA infections

Implant-related infections are a serious complication in orthopaedic and dental surgery resulting in prolonged hospitalization, high medical costs and patient mortality. The development of porous implants loaded with antibiotics may enable a local delivery for preventing surface colonization and biofilm formation. A new generation of bio-derived porous ceramic material that mimics hierarchical structures from Nature was evaluated. Silicon carbide ceramics derived from Sapelli wood (bioSiC) were obtained by pyrolysis of Entandrophragma cylindricum wood followed by infiltration with molten silicon. This process renders disks that keep the bimodal pore size distribution (3 and 85 μm) of the original material and are highly cytocompatible (BALB/3T3 cell line). The ability of the bio-ceramic to load the antimicrobial agent vancomycin was evaluated by immersion of disks in drug solutions covering a wide range of concentrations. The disks released at pH 7.4 an important amount of drug during the first 2 h (up to 11 mg/g bioSiC) followed by a slower release, which is related to the presence of macro- and mesopores. Finally, the anti-biofilm effect against methicillin resistant Staphylococcus aureus was assessed and a considerable reduction (92%) of the bacterial film was observed. Results highlight the bioSiC potential as component of medicated medical devices.

Evaluation of the potential protective effects of ad libitum black grape juice against liver oxidative damage in whole-body acute X-irradiated rats

AIMS

The aim of this study was to evaluate the potential protective effects of ad libitum black grape (Vitis labrusca) juice against liver oxidative damage in whole-body acute X-irradiated rats.

MAIN METHODS

Animals were fed ad libitum and drank voluntarily black grape juice or placebo (isocaloric glucose and fructose solution) for 6 days before and 15 days following a 6 Gy X-irradiation from a 200 kV machine.

KEY FINDINGS

Irradiated animals receiving placebo showed a significant increase in the concentration of thiobarbituric acid-reactive substances (TBARS), a marker of lipid peroxidation, as well as a significant decrease in both Cu/Zn superoxide dismutase (Cu/ZnSOD) and glutathione peroxidase (GPx) activity and reduced glutathione concentration (GSH). Black grape juice supplementation resulted in a reversal of lipid peroxidation, Cu/ZnSOD activity, and GSH concentration, towards values not significantly differing from those in non-irradiated, placebo-supplemented rats. Poly(ADP-ribose) polymerase (PARP-1) and Cu/ZnSOD changes in protein expression were observed for irradiated rats. No change in p53 expression or DNA fragmentation was found.

SIGNIFICANCE

Ad libitum black grape juice intake is able to restore the liver primary antioxidant system against adverse effects due to whole-body acute X-irradiation in rats after 15 days post-irradiation. The results support using antioxidant supplements as a preventive tool against radiation-induced harm.

Assessment of liver fibrosis before and after antiviral therapy by different serum marker panels in patients with chronic hepatitis C

BACKGROUND

Liver biopsy is the reference standard to assess liver fibrosis in chronic hepatitis C.

AIM

To validate and compare the diagnostic performance of non-invasive tests for prediction of liver fibrosis severity and assessed changes in extracellular matrix markers after antiviral treatment.

METHODS

The performances of Forns' score, AST to platelet ratio index (APRI), FIB-4 index and Enhanced Liver Fibrosis (ELF) score were validated in 340 patients who underwent antiviral therapy. These scores were determined 24 weeks after treatment in 161 patients.

RESULTS

Forns' score, APRI, FIB-4 and ELF score showed comparable diagnostic accuracies for significant fibrosis [area under the receiver operating characteristic curve (AUROC) 0.83, 0.83, 0.85 and 0.81, respectively]. To identify cirrhosis, FIB-4 index showed a significantly better performance over APRI and ELF score (AUROC 0.89 vs. 0.83 and 0.82, respectively). ELF score decreased significantly in patients with sustained virological response (SVR) (P < 0.0001) but remained unchanged in nonresponders. Non-1 hepatitis C virus (HCV) genotype, baseline lower HCV RNA, glucose, hyaluronic acid and higher cholesterol levels were independently associated with SVR.

CONCLUSIONS

Simple panel markers and ELF score are accurate at identifying significant fibrosis and cirrhosis in chronic hepatitis C. A decrease in ELF score after antiviral treatment reflects the impact of viral clearance in hepatic extracellular matrix and probably in the improvement of liver fibrosis.

Coprology of Panthera tigris altaica and Felis bengalensis euptilurus from the Russian Far East

Fecal samples from the Siberian tiger (Panthera tigris altaica) and the Amur cat (Felis bengalensis euptilurus) from Far Eastern Russia, were examined for parasites. A natural sedimentation methodology was used and a complete examination of all the sediment was performed. This fecal investigation allowed us to isolate and identify several developmental stages of gastrointestinal, hepatic, and respiratory parasites. Five parasites were found from P. t. altaica: 11 trematodes (Platynosomum fastosum) and 4 nematodes (Strongyloides sp., Ancylostomatidae, Toxascaris leonina, and Toxocara cati). Five parasites were found from F. b. euptilurus: 1 cestode (Diplopylidium sp.) and 4 nematodes (Trichuris sp., Ancylostomatidae, Toxascaris leonina, and Aelurostrongylus abstrusus). In addition, trophozoites of the amoeba Acanthamoeba sp. were detected in tiger feces.

Effect of melatonin supplementation on food and water intake in streptozotocin-diabetic and non-diabetic male Wistar rats

The effect of orally supplemented melatonin (MT) at 1 mg/kg bw for 4 weeks on feeding behavior of non-diabetic and diabetic male Wistar rats has been studied by computerized meal pattern analysis. Exogenous MT has a satiating effect in non-diabetic rats, but not in diabetic animals. The changes in feeding behavior induced by MT in non-diabetic animals are related to changes in meal frequency, size and duration leading to lower total food intake during the scotophase. MT administration to diabetic rats resulted in lower drinking time and higher faecal output, without further behavioral effects. We conclude that the notorious metabolic changes occurring in the streptozotocin-diabetic rat can overcome most of the underlying effects of MT supplementation. The possible MT usage for therapeutical purposes could benefit from the lack of behavioral alterations in diabetic animals.

Expression of pancreatic endocrine markers by mesenchymal stem cells from human umbilical cord vein

BACKGROUND

Mesenchymal stem cells (MSCs) from human umbilical cord vein have great potential for use in cell therapy because of their ease of isolation, expansion, and differentiation, in addition to their relative acceptance from the ethical point of view. Obtaining the umbilical cord at birth does not present any risk to either mother or child.

OBJECTIVE

To isolate and promote in vitro expansion and differentiation of MSCs from human umbilical cord vein into cells with a pancreatic endocrine phenotype.

METHODS

Mesenchymal stem cells obtained from human umbilical cord vein via collagenase digestion were characterized at cytochemistry and fluorescent-activated cell sorting, and expanded in vitro. Differentiation of MSCs into an endocrine phenotype was induced using high-glucose (23 mmol/L) medium containing nicotinamide, exendin-4, and 2-mercaptoethanol. Expression of insulin, somatostatin, glucagon, and pancreatic and duodenal homeobox 1 was analyzed using immunofluorescence.

RESULTS

Cells isolated from the umbilical cord vein were MSCs as confirmed at cytochemistry and fluorescent-activated cell sorting. Expression of somatostatin, glucagon, and pancreatic and duodenal homeobox 1 by differentiated cells was demonstrated using immunofluorescence. Insulin was not expressed.

CONCLUSIONS

The MSC differentiation protocol used in the present study induced expression of some endocrine markers. Insulin was not produced by these cells, probably because of incomplete induction of differentiation.