P2X(7) receptors are expressed during mouse nephrogenesis and in collecting duct cysts of the cpk/cpk mouse.

BACKGROUND: Purinergic receptors are cell-surface molecules that bind extracellular nucleotides, notably ATP. The P2X family includes seven nonselective ion channels with one member, P2X(7), implicated in cytolytic pore formation and cell death. MATERIALS AND METHODS: We sought P2X(7) expression in mouse nephrogenesis and cpk/cpk renal cyst growth, conditions in which both proliferation and apoptosis are prominent. RESULTS: P2X(7) immunolocalized to condensed metanephric mesenchyme: both proliferation and apoptosis were detected in this compartment, assessed by proliferating cell nuclear antigen expression and propidium iodide-stained pyknotic nuclei respectively. Later in nephrogenesis, P2X(7) was detected in collecting ducts, a pattern persisting to maturity. A mesenchymal to epithelial shift of P2X(7) expression was also documented in ureter development. In cpk/cpk kidneys, P2X(7)-expressing collecting duct cysts dominated histology from two weeks until four weeks after birth, when animals die from uremia. In polycystic kidneys pyknotic nuclei were rarely identified in P2X(7)-expressing epithelia, but were detected between cysts, consistent with a non-apoptotic role for P2X(7) in cyst enlargement. CONCLUSION: P2X(7) is expressed during normal nephrogenesis and in a model of congenital polycystic kidney disease. Further experiments are necessary to define possible functions of P2X(7) in these settings.     

Missed opportunities for participation in prevention of mother to child transmission programmes: Simplicity of nevirapine does not necessarily lead to optimal uptake, a qualitative study

Background  

The objective of this study was to examine missed opportunities for participation in a prevention of mother-to-child transmission (PMTCT) programme in three sites in South Africa. A rapid anthropological assessment was used to collect in-depth data from 58 HIV-positive women who were enrolled in a larger cohort study to assess mother-to-child HIV transmission. Semi-structured interviews were conducted with the women in order to gain an understanding of their experiences of antenatal care and to identify missed opportunities for participation in PMTCT.     

Delayed wound healing in Mac-1–deficient mice is associated with normal monocyte recruitment

The Mac-1 integrin is an important mediator of migration and inflammatory activation of neutrophils and monocytes. However, the role of Mac-1 in modulating macrophage emigration and activation and its subsequent impact on cutaneous wound healing have not been fully elucidated. To examine the significance of Mac-1 to murine wound healing, we measured epithelialization and granulation tissue formation in partial-thickness ear wounds and full-thickness head wounds, respectively, in Mac-1-deficient mice. Wounds were histologically analyzed at postwounding days 3, 5, and 7. The gap measured between the leading edges of inward-migrating granulation tissue was significantly increased in knockout mice compared with control animals at day 5 (3.8+/-0.3 vs. 2.6+/-0.5 mm; p<0.001) and day 7 (2.2+/-0.4 vs. 0.96+/-0.73 mm; p=0.005). Epithelial gap measurements were also increased in knockout mice vs. wild-type controls at days 3 (0.62+/-0.02 vs. 0.54+/-0.07 mm; p<0.05) and 5 (0.58+/-0.06 vs. 0.39+/-0.08 mm; p<0.001). Immunohistochemistry showed equal numbers of macrophages in knockout and control wounds. These findings show that Mac-1 is required for normal wound healing but that the attenuation in the deposition of granulation tissue and wound epithelialization in Mac-1 knockout mice is not associated with decreased monocyte migration into the wound.     

Detecting pediatric autoimmune neuropsychiatric disorders associated with streptococcus in children with obsessive-compulsive disorder and tics.

BACKGROUND: A subgroup of children with obsessive-compulsive and tic disorders are proposed to have an infectious trigger. The purpose of this study was to investigate the relationship between group A streptococcal titers and symptom fluctuations in children with a clinical course resembling that described for pediatric autoimmune neuropsychiatric disorders associated with streptococcus. METHODS: Twenty-five children with obsessive-compulsive disorder and/or tic disorder were evaluated for neuropsychiatric severity and group A streptococcal antibody titers (streptolysin O, deoxyribonuclease B, and carbohydrate A) at 6-week intervals for > or = six consecutive evaluations (total visits=277). RESULTS: Children with large symptom fluctuations (n=15) were compared with children without dramatic fluctuations (n=10). Co-movements of obsessive-compulsive/tic severity and group A streptococcal antibodies were assessed. In subjects with large symptom changes, positive correlations were found between streptococcal titers and obsessive-compulsive severity rating changes (p=.0130). These subjects were also more likely to have elevated group A streptococcal titers during the majority of observations (p=.001). Tic symptom exacerbations occurred more often in the fall/winter months than spring/summer months (p=.03). CONCLUSIONS: Patients with marked obsessive-compulsive/tic symptom changes may be characterized by streptococcal titer elevations and exhibit evidence of seasonal tic exacerbations.     

Effects of amyotrophic lateral sclerosis serum on cultured chick spinal neurons

We used a quantitative immunoassay to examine the effects of human serum and immunoglobulins on neurofilament protein expression in cultures of chick spinal neurons. Compared with cultures grown in the presence of serum from healthy controls or patients with other neurologic disorders, ALS serum lowered the level of neurofilament proteins. Effects were similar with or without muscle-derived neurotrophic factors; there was no specificity for motor neurons. No neurotoxic activity was found in immunoglobulin fractions, and there was no evidence of circulating antibodies that might neutralize muscle-derived neurotrophic factors or induce cytolysis of spinal neurons.