Metalloproteinase-9 contributes to inflammatory glia activation and nigro-striatal pathway degeneration in both mouse and monkey models of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced Parkinsonism

Inflammation is a predominant aspect of neurodegenerative diseases, manifested by glia activation and expression of pro-inflammatory mediators. Studies on animal models of Parkinson's disease (PD) suggest that sustained neuroinflammation exacerbates degeneration of the dopaminergic (DA) nigro-striatal pathway. Therefore, insights into the inflammatory mechanisms of PD may help the development of novel therapeutic strategies against this disease. As extracellular matrix metalloproteinases (MMPs) could be major players in the progression of Parkinsonism, we investigated, in the substantia nigra and striatum of mice acutely injected with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), changes in mRNA expression, protein levels, and cell localization of MMP-9. This protease is mainly neuronal, but early after MPTP injection its mRNA and protein levels, as well as the number of MMP-9-expressing microglia and astrocytes, increase concomitantly to a prominent inflammation. Neuroinflammation and MMP-9(+) glia begin to decline within 2 weeks, although protein levels remain higher than control, in association with a partial recovery of DA nigro-striatal circuit. Comparable quantitative studies on MMP-9 knock-out mice, show a significant decrease in both glia activation and loss of DA neurons and fibers, with respect to wild-type. Moreover, in a parallel study on chronically MPTP-injected macaques, we observed that perpetuation of inflammation and high levels of MMP-9 are associated to DA neuron loss. Our data suggest that MMP-9 released by injured neurons favors glia activation; glial cells in turn reinforce their reactive state via autocrine MMP-9 release, contributing to nigro-striatal pathway degeneration. Specific modulation of MMP-9 activity may, therefore, be a strategy to ameliorate harmful inflammatory outcomes in Parkinsonism.

Combination of low dose of the anti-adipogenic agents resveratrol and phenelzine in drinking water is not sufficient to prevent obesity in very-high-fat diet-fed mice

PURPOSE

Resveratrol inhibits lipid accumulation but suffers from limited bioavailability. The anti-depressive agent phenelzine limits adipogenesis in various models of cultured preadipocytes, and this hydrazine derivative also inhibits de novo lipogenesis in mature adipocytes. It was therefore tested whether resveratrol effects on adiposity reduction and glucose tolerance improvement could be reinforced by co-administration with phenelzine.

METHODS

Mice fed a very-high-fat diet (VHFD, 60% calories as fat) were subjected to drinking solution containing low dose of resveratrol (0.003%) and/or 0.02% phenelzine for 12 weeks. Body fat content, glucose tolerance, food and water consumption were checked during treatment while fat depot mass was determined at the end of supplementation. Direct influence of the agents on lipogenesis and glucose uptake was tested in adipocytes.

RESULTS

Epididymal fat depots were reduced in mice drinking phenelzine alone or with resveratrol. No limitation of body weight gain or body fat content was observed in the groups drinking resveratrol or phenelzine, separately or in combination. The altered glucose tolerance and the increased fat body composition of VHFD-fed mice were not reversed by resveratrol and/or phenelzine. Such lack of potentiation between resveratrol and phenelzine prompted us to verify in vitro their direct effects on mouse adipocytes. Both molecules inhibited de novo lipogenesis, but did not potentiate each other at 10 or 100 μM. Only resveratrol inhibited hexose uptake in a manner that was not improved by phenelzine.

CONCLUSIONS

Phenelzine has no interest to be combined with low doses of resveratrol for treating/preventing obesity, when considering the VHFD mouse model.

Development of multi-physics code systems based on the reactor dynamics code DYN3D

The reactor dynamics code DYN3D has been coupled with the CFD code ANSYS CFX and the 3D thermal hydraulic core model FLICA4. In the coupling with ANSYS CFX, DYN3D calculates the neutron kinetics and the fuel behavior including the heat transfer to the coolant. The physical data interface between the codes is the volumetric heat release rate into the coolant. In the coupling with FLICA4 only the neutron kinetics module of DYN3D is used. Fluid dynamics and related transport phenomena in the reactor's coolant and fuel behavior is calculated by FLICA4.

The correctness of the coupling of DYN3D with both thermal hydraulic codes was verified by the calculation of different test problems. These test problems were set-up in such a way that comparison with the DYN3D stand-alone code was possible. This included steady-state and transient calculations of a mini-core consisting of nine real-size PWR fuel assemblies with ANSYS CFX/DYN3D as well as mini-core and a full core steady-state calculation using FLICA4/DYN3D.

Boerhaave's syndrome: a differential diagnosis of acute chest pain following a vomiting illness

Spontaneous oesophageal rupture (Boerhaave's syndrome) is extremely rare in children. Presentation is usually in middle aged men as a result of vomiting following heavy food or alcohol consumption. We describe an unusual case of a 12-year old boy without significant past medical history presenting with acute chest pain following gastroenteritis.

Collaboration and research as key elements for strengthening blood donation in developing nations: the case of Grenada, West Indies

OBJECTIVE

The purpose of the study was to identify ways to strengthen the collaboration between the Grenadian Blood Bank, the St George's University (SGU) chapter of the American Medical Students Association, and St George's University Health Clinic in order to improve the promotion of blood drives and increase the number of volunteer donors.

METHODS

The study had two phases. Phase 1: an assessment of the strengths and needs of the collaborators and of the blood drives. Phase 2 consisted of three student assessments: a cross-sectional survey of second year medical students, a cross-sectional survey of students in the School of Arts and Sciences and a case-control study of factors affecting student donation on the day of blood drives. Embedded within both phases were service-learning opportunities for students. Both phases received approval from SGU's Institutional Review Board.

RESULTS

Preliminary achievements included a transient increase in blood donation of twenty per cent during five months though advertising of blood drives remains inadequate. Assessments reveal that most students lack knowledge about the drives, and time (medical students) and fear of needles and infection (Arts and Science students) are potential hindrances to blood donation.

CONCLUSIONS

The Blood Bank needs to increase its profile on the university campus and develop a more effective promotion of the blood drives addressing the concerns of students. St George's University needs to continue supporting student involvement in health promotion activities and identify ways to ensure the sustainability and continuity of these activities. Collaboration and research are useful and effective means to promote blood donation. College students are potentially an excellent source of collaborators and donors if provided with the promotion skills and participation is made convenient.

An experimental infection model to induce digital dermatitis infection in cattle

Bovine digital dermatitis (DD), also known as papillomatous digital dermatitis (foot warts), has been recognized as a major cause of lameness in cattle, with important economic and welfare consequences. The evaluation of therapeutic and preventive interventions aiming to control DD infections in dairy cattle is often challenged by the complex multifactorial etiology of the disease. An experimental infection model to induce acute DD lesions in a controlled environment is proposed. The goal was to provide a standard way of reproducing DD infections independent of external factors that could confound the natural course of the disease, such as management practices or infection pressure, resulting in transmission of DD between animals. A group of 4 yearling Holstein heifers free of any clinical evidence of hoof disease was recruited from a commercial dairy farm and housed in an experimental facility in 1 pen with slatted flooring. The hind feet were wrapped to mimic conditions of prolonged moisture (maceration) and reduced access to air (closure) and inoculated at the heel and dewclaw areas with a homogenate of a naturally occurring DD lesion skin biopsy or a culture broth of Treponema spp. After a period of 12 to 25 d, 4 of 6 and 1 of 4 dewclaw areas inoculated with biopsied DD lesion or a Treponema spp. culture, respectively, had gross lesions compatible with DD. Histopathology confirmed the gross diagnosis in the sites inoculated with tissue homogenate. In the site inoculated with Treponema spp. culture broth, histopathology revealed an incipient DD lesion. Treponema spp. were detected by PCR in both naturally occurring DD homogenate and Treponema spp. culture broth inoculation sites. An experimental infection model to induce acute DD in cattle was developed, which may be used to evaluate interventions to control DD and study the pathogenesis of this infectious hoof disease in a controlled manner.

Use of small bowel MRI enteroclysis in the management of paediatric IBD

INTRODUCTION

Children with inflammatory bowel disease (IBD) frequently present with small bowel involvement at some stage of their disease. Hence, reliable assessment of the entire small bowel is required in order to adjust treatment accordingly. Recently, magnetic resonance imaging (MRI) of the small bowel in combination with luminal contrast agent delivered via a naso-jejunal tube (MR enteroclysis) is an emerging technique demonstrating good results in adult patients. However, data on its use and benefits in children is limited.

AIMS

In this study we report our experience on performing small bowel MR enteroclysis (MRE) in children with IBD. Specifically, we reviewed indications, MR findings, advantages and disadvantages of the technique in a tertiary unit.

METHODS

A total of 34 MRE studies (29 paediatric IBD patients) were retrospectively analysed. All patients underwent upper and lower endoscopy under general anaesthetic (GA) the day before MR imaging was performed. Nasojejunal (NJ)-tube was placed during endoscopy.

RESULTS

Frequently detected findings included small and large bowel wall thickening, small bowel strictures and intestinal lymph node enlargement. Importantly, in all our clinical cases, MRE results were key to making a clinical decision in the given scenario regardless of whether MRE findings were positive or negative.

CONCLUSIONS

Within our setup, MR enteroclysis is a well-tolerated, sensitive technique for small bowel imaging, providing detailed information at crucial clinical decision points. Moreover, accurate information then allows appropriate clinical decisions to be made.

IgA NMDA receptor antibodies are markers of synaptic immunity in slow cognitive impairment

OBJECTIVE

To report that antibodies to synaptic proteins may occur in association with slow, progressive cognitive decline.

METHODS

A total of 24 patients with progressive cognitive dysfunction of unclear etiology were examined for onconeuronal and synaptic receptor antibodies. The effect of serum was examined in cultures of dissociated mouse hippocampal neurons.

RESULTS

Seven patients had immunoglobulin A (IgA), but no immunoglobulin G (IgG), antibodies against NMDA receptor (NMDAR). Anti-NMDAR IgA positive patients' serum, but not serum from control individuals, caused dramatic decrease of the levels of NMDAR and other synaptic proteins in neurons, along with prominent changes in NMDAR-mediated currents. These effects correlated with the titer of IgA NMDAR antibodies and were reversed after removing patients' serum from the culture media. When available, comprehensive clinical assessment and brain metabolic imaging showed neurologic improvement after immunotherapy.

CONCLUSIONS

A subset of patients with slowly progressive cognitive impairment has an underlying synaptic autoimmunity that decreases the density of NMDAR and other synaptic proteins, and alters synaptic currents. This autoimmunity can be demonstrated examining patients' serum and CSF for NMDAR IgA antibodies, identifying possible candidates for immunotherapy.

The single-nucleotide polymorphism T>C rs4353229 in CASP7 gene and mir-224 as new biomarkers of oxaliplatin-induced neurotoxicity in advanced colorectal cancer

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Background: Oxaliplatin represents a central component of colorectal (CCR) cancer treatment. It is known that the ways in which oxaliplatin is neurotoxic include not only DNA damage, but also the modulation of specific molecules, such as caspases 3 and 7, involved in regulating the cellular equilibrium between apoptotic death and the cell cycle. MiRNAs are non-coding RNAs that can block mRNA traslation. Recent evidences indicate that variations in miRNA binding sites may contribute to the susceptibility to CCR. However, the effect of these SNPs on miRNA-target interaction remains to be determined. The SNP T>C rs4353229 in CASP7 gene is binding site of miR-224. We hypothesize that miR-224 and the SNP T>C rs4353229 could be new predictive biomarkers of oxaliplatin-induced neurotoxicity in advanced colorectal cancer.

Methods: We examined the SNP T>C rs4353229 in CASP7 gene in 62 patients with advanced CCR. All patients had received first line of chemotherapy based in fluoropirimidines plus oxaliplatin. The Oxaliplatin-Specific Neurotoxicity Scale was utilized to assess oxaliplatin-related symptoms. Time to progresion (TTP) and objetive response rate (ORR) were calculated. Genomic DNA was extracted from peripheral blood and genotyped by allelic discrimination. We explored the possible correlation of rs4353229 with neurotoxicity, DCR and TTP using and Chi-cuadrado test and Kaplan-Meier model (log rank) respectively.

Results: SNP distribution was 3,2% (ancestral homozygous CC), 46,7% (variant homocygous TT) and 43,7% (heterocygous CT). Median TTP was 10 months (IC95%: 7,4-12,5); regarding CASP7 polymorphism, there were not differences (p=0,41; log rank). ORR was 64,5% and there are not differences between CC, CT and TT patients (p=0,50). Fifteen patients experienced neurotoxicity grade III/IV (24,19%) and it was correlated significantly with ancestral homoygous CC patients (p=0,003).

Conclusions: The SNP T>C rs4353229 in CASP7 gene and miR-224 may be new candidates predictor of oxaliplatin-induced neurotoxicity. Further characterization of CASP7 SNPs and miR-224 may open new avenues for the study of cancer and therapeutic interventions.

Hypovitaminosis D as a risk factor of hip fracture severity

SUMMARY

In a cross-sectional study including 324 patients older than 65 years admitted to our hospital for osteoporotic hip fracture, we found that those patients with a more severe vitamin D deficiency had more severe osteoporotic hip fractures (Garden grades III-IV and Kyle III-IV).

INTRODUCTION

To identify possible differences in baseline characteristics of patients with different types of osteoporotic hip fracture.

METHODS

Cross-sectional study including consecutive individuals over 65 admitted to our hospital for osteoporotic hip fracture over a year. Demographic data, fracture type, comorbidities, history of osteoporosis, functional capacity, nutritional status and vitamin D storage were evaluated.

RESULTS

We included 324 patients (83 ± 7 years, 80% women). Two hundred sixteen patients (67%) had vitamin D deficiency (25OHD3 <25 ng/ml). In patients with severe femoral neck or intertrochanteric fractures (Garden III-IV and Kyle III-IV), vitamin D deficiency was more frequent (74%) and severe (25OHD3 20 ± 15 ng/ml) than in patients with less severe fractures (57%, 25OHD3 26 ± 21 ng/ml). Forty-three percent of patients had previous fractures. Only 15% of patients had been previously diagnosed with osteoporosis and 10% were receiving treatment. Patients receiving vitamin D supplements have higher 20OHD3 levels and less severe fractures.

CONCLUSIONS

Although vitamin D levels are not different between patients with intracapsular or extracapsular hip fractures, a more severe vitamin D deficiency seems to be associated to more severe osteoporotic hip fractures. A prior vitamin D supplementation could avoid a higher severity of these fractures.

An assessment of knowledge, attitudes and behaviour regarding the human papillomavirus

OBJECTIVES

This report is based on a study conducted in February 2010 that assessed the knowledge and attitudes toward cervical cancer and human papillomavirus (HPV) in Grenada which has a high incidence of cervical cancer.

METHODS

The participants were 71 students at the St George's University. There were 58 females and 13 males who participated in the study, a ratio of 4.5:1. Participants were asked to complete a survey on their knowledge and attitudes about HPV cervical cancer and the associated risk factors. Other evaluations of their levels of risk and Pap smear practices were also assessed.

RESULTS

The data reflected low knowledge and infrequent screening practices, from a public health perspective, when compared with developed countries. The data showed a significant deficit in knowledge of both males and females. Almost 95% of the women surveyed were able to correctly identify the purpose of a Pap smear as compared to 69.2% of the men surveyed. When the participants were asked what was the cause of cervical cancer 63.8% of women and 53.8% of males were correctly able to identify the HPV.

CONCLUSIONS

Enhanced educational programmes are needed to reduce the burden of cervical cancer that exists in Grenada.