An investigation to assess the potential of CD25highCD4+ T cells to regulate responses to donor alloantigens in clinically stable renal transplant recipients.

Regulatory T cells are enriched within CD25(high)CD4(+) leukocytes, however their role in renal transplant recipients with stable function vs. recipients with biopsy-proven chronic allograft dysfunction remains unclear. We therefore studied the number, phenotype, and function of CD25(high)CD4(+) cells in the peripheral blood of 30 renal transplant recipients of living-related grafts, comprising 15 rejection-free recipients with stable graft function (Group A) and 15 with biopsy-proven chronic graft dysfunction (Group B). A higher absolute number of CD25(high)CD4(+) cells were present in the peripheral blood of rejection-free recipients (Group A) vs. those recipients with chronic graft dysfunction (Group B) (P = 0.019); but there was no significant difference with healthy volunteers (P = 0.084). In carboxyfluorescein diacetate succinimidyl ester-mixed leukocyte culture assays, depletion of CD25(high)CD4(+) revealed active regulation in 11 (74%) of 15 rejection-free recipient samples (Group A) in response to donor- but not third party-leukocytes, whereas no regulatory activity was observed in any samples from recipients with chronic graft dysfunction (Group B). In conclusion, these data provide evidence for the presence of an increased number of CD25(high)CD4(+) T cells with donor-specific regulatory activity in the peripheral blood of renal transplant recipients with stable graft function compared with recipients with chronic graft dysfunction.     

2-Methoxyestradiol and multidrug resistance: can 2-methoxyestradiol chemosensitize resistant breast cancer cells?

2-Methoxyestradiol (2ME), a natural derivative of estradiol, is currently evaluated in clinical trials for breast cancer. The current study aims to evaluate the modulatory effects of 2ME on regulation of multidrug resistance (MDR) in doxorubicin (Dox) resistant breast cancer cells (MCF-7/Dox) and its underlying mechanisms. The chemosensitizing effect of 2ME on Dox cytotoxicity is tested by MTT assay. RT² Profiler PCR Array was used to identify differentially expressed genes in Dox and/or 2ME treatment groups, based on significance of results 4 genes were selected: MDR1, Bcl2, P53 and Cyclin D1. The expression of these genes was confirmed using western blotting. Lastly, functions of these genes were examined by studying p-glycoprotein (p-gp) function, caspase 3 activity and flowcytometric cell cycle assays respectively. 2ME significantly increased sensitivity of the resistant MCF-7/Dox cells to the cytotoxic effect of Dox by 2.9-folds. The array and western blotting showed that Bcl2 and Cyclin D1 expression were down regulated; P53 expression was not affected while MDR1 was over expressed by combination of 2ME with Dox. 2ME increased p-gp function by 24 ± 7.05%, compared to control. Addition of 2ME to Dox increased caspase activity by 27-folds. Combination of 2ME to Dox arrested the cell cycle in G₁ and S phases, compared to Dox. In conclusion, 2ME chemosensitizes resistant breast cancer cells to Dox cytotoxcity by down regulating expression of Bcl2 and Cyclin D1, augmenting caspase 3 activity as well as inducing cell cycle block in G₁ and S phases.     

Association of a 27-bp repeat polymorphism in intron 4 of endothelial constitutive nitric oxide synthase gene with hypertension in a Tunisian population

Objectives

Nitric oxide (NO) produced by endothelial nitric oxide synthase (eNOS) mediates endothelium-dependent vasodilatation and antithrombotic action. Controversial results regarding the association of eNOS gene (NOS3) polymorphisms with hypertension have been reported. In the present study, we examined a possible association between the 27-base pair (bp) repeat polymorphism in intron 4 of the NOS3 gene and hypertension in a sample of the Tunisian population.

Design and methods

A total of 295 Tunisian patients with hypertension and 395 healthy controls were included in the study. The NOS3 gene intron 4a4b variable number of tandem repeats polymorphism was analyzed by PCR.

Results

A significant differences in genotype distribution and allele frequency was observed between patients and controls. Patients with hypertension had a frequency of 6.4% for the 4a4a genotype, 32.7% for the 4a4b genotype and 60.9% for the 4b4b genotype. The controls had a frequency of only 2.3% for the 4a4a genotype, 28.4% for the 4a4b genotype and 69.4% for the 4b4b genotype (χ² = 11.81, p = 0.003). The hypertension patient group showed a significant higher frequency of the 4a allele compared to the controls (0.23 vs. 0.16; χ² = 8.61, p = 0.003). The odds ratio of hypertension for 4a vs 4b allele frequencies was statistically significant 1.66 [1.09-2.53] at 95% CI, p = 0.01 in males, whereas it was non-significant in females (1.23 [0.84-1.81], p = 0.26).

Conclusion

The present study showed a significant and independent association between the NOS34a4b gene polymorphism (presence of 4a allele) and hypertension in the Tunisian population.     

Weight Suppression in Eating Disorders: a Research and Conceptual Update

Purpose of Review

Weight suppression, the discrepancy between an individual’s highest past weight at adult height and his or her current weight, is related to many characteristics of individuals with eating disorders. This paper reviews research findings from the past 5 years, draws several implications regarding the mechanism underlying these effects, and proposes new approaches to measuring weight suppression.

Recent Findings

Studies were reviewed under the categories of anorexia nervosa, bulimia nervosa, and mixed or miscellaneous samples, with more studies falling into the last category than in the first two. Recent findings have continued to show that weight suppression is related to a wide variety of biological and behavioral features in both diagnosed and sub-clinical samples.

Summary

Weight suppression promotes weight gain which is anathema to individuals with eating disorders, putting them in a biobehavioral bind that appears to prolong their disorder. Priorities for future research are to understand the mechanisms underlying the effects of weight suppression, evaluate new ways of defining weight suppression, and study its implications for modifying treatment.

     

Nogo receptor expression in microglia/macrophages during experimental autoimmune encephalomyelitis progression

Myelin-associated inhibitory factors within the central nervous system(CNS) are considered to be one of the main obstacles for axonal regeneration following disease or injury. The nogo receptor 1(NgR1) has been well documented to play a key role in limiting axonal regrowth in the injured and diseased mammalian CNS. However, the role of nogo receptor in immune cell activation during CNS inflammation is yet to be mechanistically elucidated. Microglia/macrophages are immune cells that are regarded as pathogenic contributors to inflammatory demyelinating lesions in multiple sclerosis(MS). In this study, the animal model of MS, experimental autoimmune encephalomyelitis(EAE) was induced in ngr1~(+/+) and ngr1~(–/–) female mice following injection with the myelin oligodendrocyte glycoprotein(MOG_(35–55)) peptide. A fatemap analysis of microglia/macrophages was performed throughout spinal cord sections of EAE-induced mice at clinical scores of 0, 1, 2 and 3, respectively(increasing locomotor disability) from both genotypes, using the CD11 b and Iba1 cell markers. Western immunoblotting using lysates from isolated spinal cord microglia/macrophages, along with immunohistochemistry and flow cytometric analysis, was performed to demonstrate the expression of nogo receptor and its two homologs during EAE progression. Myelin protein engulfment during EAE progression in ngr1~(+/+) and ngr1~(–/–) mice was demonstrated by western immunblotting of lysates from isolated spinal cord microglia/macrophages, detecting levels of Nogo-A and MOG. The numbers of M1 and M2 microglia/macrophage phenotypes present in the spinal cords of EAE-induced ngr1~(+/+) and ngr1~(–/–) mice, were assessed by flow cytometric analysis using CD38 and Erg-2 markers. A significant difference in microglia/macrophage numbers between ngr1~(+/+) and ngr1~(–/–) mice was identified during the progression of the clinical symptoms of EAE, in the white versus gray matter regions of the spinal cord. This difference was unrelated to the expression of Ng R on these macrophage/microglial cells. We have identified that as EAE progresses, the phagocytic activity of microglia/macrophages with myelin debris, in ngr1~(–/–) mice, was enhanced. Moreover, we show a modulation from a predominant M1-pathogenic to the M2-neurotrophic cell phenotype in the ngr1~(–/–) mice during EAE progression. These findings suggest that CNS-specific macrophages and microglia of ngr1~(–/–) mice may exhibit an enhanced capacity to clear inhibitory molecules that are sequestered in inflammatory lesions.     

Use of Transcyte and dermabrasion to treat burns reduces length of stay in burns of all size and etiology

BACKGROUND: With the cost of healthcare increasing, greater emphasis is placed on finding better ways to manage burn patients by increasing the quality of care while reducing length of hospital stay (LOS), thereby reducing overall cost. To date, this is the largest study to determine if Transcyte reduces LOS for partial thickness burns of any size or etiology. METHODS: All consecutive patients with deep partial thickness burns from April 2002 to December 2002 were reviewed (n=110) with IRB approval. Ninety-two patients were treated with dermabrasion and Transcyte only. Eighteen patients were treated with a combination of STSG and dermabrasion and Transcyte where appropriate. Our data was compared to the American Burn Association Patient Registry, as reported by Saffle et al. 1995. RESULTS: The data for percent TBSA and LOS are reported as mean+/-S.E.M. One-tailed t-test was used to analyze the data. Significant difference was found in patients who were treated with dermabrasion and Transcyte compared to the population reported by Saffle et al. Patients with 0-19.9% TBSA burn treated with dermabrasion and Transcyte had LOS of 6.1 days versus 9.0 days (p<0.001). Those with 20-39.9% TBSA burn had length of stay of 17.5 days versus 25.5 days. Patients treated with STSG and Transcyte who had 40-59.9% TBSA burn had length of stay of 39.7 days versus 44.6 days. Those treated with dermabrasion and Transcyte alone had length of stay of 31 days. CONCLUSION: This is the first study comparing burns of all sizes treated with dermabrasion and Transcyte with a known population receiving standard therapy. The authors found this new method of managing patients with partial thickness burns to be more efficacious and significantly reduces length of stay compared to traditional management.     

Molecular detection of Babesia equi in infected and carrier horses by polymerase chain reaction

Twenty-three blood samples were used in this study; five were from five naturally infected horses with Babesia equi (B. equi), while eighteen were from asymptomatic horses with equine babesiasis from different localities in Egypt. All samples were subjected to microscopic examination, indirect fluorescent antibody test (IFA) and polymerase chain reaction (PCR). The carrier animals were microscopically detected in 7 out of 18 samples (38.8%) and in 9 of 18 by using IFA (50%), whereas PCR revealed that 14 samples were positive (78%). Two synthetic oligonucleotide primers, based on the B. equi merozoite antigen gene (EMA-1) were used. A 819 bps DNA fragment is specifically amplified from the gene encoding EMA-1 of B. equi. Our results demonstrate that PCR is a valuable technique for routine detection of B. equi in chronically infected horses, even at low parasitaemia levels.