Role of chloride transport proteins in the vasorelaxant action of nitroprusside in isolated rat aorta

Chloride ions play a key role in smooth muscle contraction, but little is known concerning their role in smooth muscle relaxation. Here we investigated the effect of chloride transport inhibitors on the vasorelaxant responses to nitroprusside in isolated and endothelium-denuded rat aorta, precontracted with phenylephrine 1 muM. Incubation of aortic rings in NO(3)(-) media strongly potentiated the vasorelaxant responses to nitroprusside. Bumetanide, DIDS (4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid) and acetazolamide strongly potentiated the vasorelaxant responses to nitroprusside (by 70-100%). EC(50) were 2.3+/-0.5 microM for bumetanide, 26+/-15 microM for DIDS and 510+/-118 microM for acetazolamide (n=6 for condition). Niflumic acid, a selective inhibitor of ClCa (calcium-activated chloride channels), potentiated nitroprusside relaxation to a similar extent as chloride transport inhibitors, in a non-additive manner. Zinc and nickel ions, both modestly potentiated nitroprusside vasorelaxation (by 20-30%). Cobaltum had negligible effect on nitroprusside vasorelaxation. CPA (p-chlorophenoxy-acetic acid), an inhibitor of volume-sensitive chloride channels (ClC), slightly potentiated nitroprusside vasorelaxation (by 15%), and the cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel inhibitors CFTR(inh)172 (5-[(4-Carboxyphenyl)methylene]-2-thioxo-3-[(3-trifluoromethyl)phenyl-4-thiazolidinone), DPC (diphenylamine-2,2'-dicarboxylic acid) and glibenclamide were without significant effect. In conclusion, inhibition of chloride transport proteins strongly potentiates the vasorelaxant responses to nitroprusside in isolated rat aorta. This effect seems mediated by chloride depletion and inhibition of a chloride channel activated by both, calcium and cyclic GMP (cGMP).     

Human cytomegalovirus-specific T-cell immune reconstitution in preemptively treated heart transplant recipients identifies subjects at critical risk for infection

Human cytomegalovirus (CMV) infection represents a major threat for heart transplant recipients (HTXs). CMV-specific T cells effectively control virus infection, and thus, assessment of antiviral immune recovery may have clinical utility in identifying HTXs at risk of infection. In this study, 10 CMV-seropositive (R(+)) pretransplant patients and 48 preemptively treated R(+) HTXs were examined before and after 100 days posttransplant. Preemptive treatment is supposed to favor the immune recovery. CMV DNAemia and gamma interferon enzyme-linked immunosorbent spot (ELISPOT) assay were employed to assess the viremia and immune reconstitution. HTXs could be categorized into three groups characterized by high (>100), medium (50 to 100), and low (<50) spot levels. Early-identified high responders efficiently controlled the infection and also maintained high immunity levels after 100 days after transplant. No episodes of grade ≥2R rejection occurred in the high responders. Midresponders were identified as a group with heterogeneous trends of immune reconstitution. Low responders were 41% and 21% of HTXs before and after 100 days posttransplant, respectively. Low responders were associated with a higher incidence of infection. The effect of viremia on immune recovery was investigated: a statistically significant inverse correlation between magnitude of viremia and immune recovery emerged; in particular, each 10-fold increase in viremia (>4 log(10) DNAemia/ml) was associated with a 36% decrease of the ELISPOT assay spot levels. All episodes of high viremia (>4 log(10) DNAemia/ml) occurred from 1 to 60 days after transplant. Thus, the concomitant evaluation of viremia and CMV immune reconstitution has clinical utility in identifying HTXs at risk of infection and may represent a helpful guide in making therapeutic choices.     

Atypical lesions as a sign of cutaneous dissemination of visceral leishmaniasis in a human immunodeficiency virus-positive patient simultaneously infected by two viscerotropic Leishmania species

Leishmaniasis is considered an emerging opportunistic disease in human immunodeficiency virus (HIV)-infected patients who have considerably variable clinical presentation. We report a patient with visceral leishmaniasis who had unexpected clinical aspects (atypical cutaneous lesions appearing after long-term evidence of visceral parasites). The patient had hepatoesplenomegaly in the absence of fever, but was otherwise generally healthy. The HIV viral load was low despite severe immunossupression (low lymphocyte proliferation and low level of interferon-γ, concomitant with a high lymphocyte activation status). Surprisingly, two Leishmania strains were isolated from his bone marrow (typical L. infantum sequence MON-1, type A) and skin (L. donovani MON-2 sequence); this second strain had not been previously identified in Brazil. The association of visceral leishmaniasis and HIV/acquired immunodeficiency syndrome is a largely unknown disease, particularly in areas in which leishmaniasis is not endemic. Such atypical cases indicate that this disease can be undiagnosed in clinical settings.     

Nursing staff absenteeism rates as a personnel management indicator

Absenteeism in nursing is a difficult problem for health organizations; hence it is an indicator that must be monitored. The objective of this study was to analyze the absenteeism rate of nursing professionals in a public hospital. Absenteeism data were collected monthly, from January to July 2008, and calculated by means of an electronic program. The mean absenteeism index for nurses varied from 5.6% to 9.7% for technicians/nursing aides. Sick leaves were the most prevalent reason for absences. The data revealed the major cause of absenteeism and pointed at the need to change policies for hiring nursing professionals, in addition to reviewing the working processes in order to improve the workers' health conditions.     

Difference in adhesion molecule expression (ICAM-1 and VCAM-1) in juvenile and adult dermatomyositis, polymyositis and inclusion body myositis

To assess the differential expression of adhesion molecules ICAM-1 and VCAM-1 in vessels and muscle fibers in acquired inflammatory myopathy, a series comprising thirty-seven muscle biopsy specimens from patients with JDM, fifteen with DM, fifteen with PM and seven with IBM was studied. Histochemical and immunohistochemical tests (StreptABCcomplex/HRP) for ICAM-1 and VCAM-1 (Dakopatts) were performed in serial frozen sections. ICAM-1 expression in vessels was significantly (p<0.0001) more present in JDM than PM, DM or IBM. However, in muscle fibers, ICAM-1 expression was absent in both JDM and IBM, but present in 33.4% and 40% in PM and DM respectively (p<0.0001). VCAM-1 expression in vessels was significantly more present in PM and DM than JDM and IBM (p<0.0001) while VCAM-1 expression in muscle fibers was almost absent in the four groups (p=0.2632). These findings emphasize the importance of adhesion molecules in the pathophysiology of the inflammatory myopathies, mainly the marked ICAM-1 expression in vessels in JDM, corroborating the microvascular involvement in this disease. In contrast, VCAM-1 seems not to play a major role in JDM, as previously described in PM, DM and IBM. Adhesion molecule expression in JDM presents a differential characteristic when compared to PM, DM and IBM.     

Prevalence of congenital heart disease in schoolchildren of sub-Saharan Africa, Mozambique

A survey conducted by cardiologists in Mozambique provided an opportunity for assessing the prevalence of congenital heart disease in public school children in Maputo. After randomization, a total of 2170 children were examined. Five children had clinical and echographic evidence of congenital heart disease, corresponding to a prevalence of 2.3 in 1000 (95% confidence interval: 1.0 to 5.4), 80% newly discovered during the survey. These findings confirm that congenital heart disease is at least as common in this South African black community as in Caucasians. Early detection of these cardiac diseases in children is important in order to prevent serious complications and to institute endocarditis prevention.     

Parallel increase of circulating CXCL11 and CXCL10 in mixed cryoglobulinemia, while the proinflammatory cytokine IL-6 is associated with high serum Th2 chemokine CCL2

The aim was to investigate circulating levels of interelukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α, chemokine (C–X–C motif) ligand (CXCL)10, CXCL11 and chemokine (C–C motif) ligand (CCL)2 in “mixed cryoglobulinemia and hepatitis C” (MC?+?HCV). Serum levels of CXCL11, IL-1β, TNF-α, IL-6, and CCL2 were evaluated in 52 MC?+?HCV vs 52 sex- and age-matched controls to correlate them to the clinical features of mixed cryoglobulinemia. CXCL11 was significantly higher in MC?+?HCV than in controls (264?±?279 vs 70?±?16 pg/mL, respectively; P?=?0.0002; univariate analysis of variance (ANOVA)), in particular in 23 MC?+?HCV with active vasculitis vs those without (293?±?221 vs 168?±?57 pg/mL, respectively; P?<?0.001; ANOVA). Significantly high IL-1β, IL-6, TNF-α, CXCL10, and CCL2 in MC?+?HCV vs healthy controls were confirmed. In a multiple linear regression model (CXCL11 or CCL2, vs age, alanine aminotransferase, IL-1β, IL-6, TNF-α, and CXCL10), CXCL11 was significantly associated with high CXCL10 (P?<?0.001), while CCL2 with high IL-6 (P?<?0.001). This study demonstrates in MC?+?HCV high serum levels of (a) T-helper 1 chemokines, CXCL11 and CXCL10 (related to each other) and (b) proinflammatory cytokines IL-6 and CCL2 (related to each other).     

Age-related dysfunction of the lacrimal gland and oxidative stress: evidence from the Cu,Zn-superoxide dismutase-1 (Sod1) knockout mice

An imbalance between free radical generation and radical scavenging antioxidant systems results in oxidative stress, which has been associated with cell injury observed in many age-related diseases. The superoxide dismutase (SOD) family is a major antioxidant system, and deficiency of Cu,Zn-superoxide dismutase-1 (Sod1) in mice leads to many different phenotypes that resemble accelerated aging. In this study we examined the morphologic features and the secretory functions of the lacrimal glands in Sod1(-/-) mice. Lacrimal glands showed atrophy of acinar units; fibrosis; infiltration with CD4(+) T cells, monocytes, and neutrophils; increased staining with both 4-hydroxy-2-nonenal and 8-hydroxy-2'-deoxyguanosine; increases in apoptotic cells; and the presence of the epithelial-mesenchymal transition in senescent Sod1(-/-) mice. Electron microscopy findings revealed evidence of epithelial-mesenchymal transition, presence of swollen and degenerated mitochondria, and the presence of apoptotic cell death in the lacrimal glands of senescent Sod1(-/-) mice. These alterations were also associated with the accumulation of secretory vesicles in acinar epithelial cells, decreased production of both stimulated and nonstimulated tears, and a decline in total protein secretion from the lacrimal glands. Our results suggest that Sod1(-/-) mice may be a good model system in which to study the mechanism of reactive oxygen species-mediated lacrimal gland alterations.