Acute and chronic regulation of thick ascending limb endothelial nitric oxide synthase by statins

Statins, 3-hydroxy-3-methylglutaryl CoA reductase inhibitors, acutely increase endothelial nitric oxide synthase (eNOS) activity and chronically increase eNOS expression in endothelial cells. NO decreases transport in thick ascending limbs (TAL). We hypothesized that statins inhibit TAL transport by acutely activating eNOS, thereby increasing NO production and chronically enhancing eNOS expression. Oxygen consumption (QO(2)) by TAL suspensions from Sprague-Dawley rats was used as a measure of active NaCl reabsorption. Na/K ATPase activity was assessed by measuring ATP hydrolysis in the presence and absence of ouabain. eNOS expression was measured by Western blot. A total of 50 micro M pravastatin decreased QO(2) by 18.6 +/- 3.4% (P < 0.01). In the presence of 500 micro M furosemide and 200 micro M amiloride, transport blockers, QO(2) remained the same after pravastatin was added. Na/K ATPase activity was not different from controls and TAL treated with 50 micro M pravastatin (0.33 +/- 0.07 versus 0.29 +/- 0.04 nmol P(i)/ micro g protein/min, where P(i) is inorganic phosphate). Nystatin stimulated QO(2) to 178 +/- 13.7 in pravastatin-treated TAL and 195 +/- 11.5 in furosemide-treated TAL. The inhibitory effect of pravastatin on QO(2) was blocked by L-nitroarginine methyl ester, an NOS inhibitor. In addition, pravastatin increased NO production as measured by the fluorescent dye DAF-2A. Pravastatin at a dose of 10 mg/kg per d had no effect on eNOS protein at 1 d (24.1 +/- 2.7 versus 25.5 +/- 1.1 arbitrary units [AU]) or 7 d (24.1 +/- 2.7 versus 20.9 +/- 1.3 AU). Similarly, at 1 d, 50 mg/kg per d had no effect on expression (24.1 +/- 2.7 versus 21.2 +/- 3.6 AU). At 7 d, this dose decreased eNOS protein from 24.1 +/- 2.7 to 11.8 +/- 4.4 AU. It is concluded that pravastatin acutely decreases NaCl entry into the TAL by releasing NO. Pravastatin does not chronically increase eNOS expression in TAL.     

Stabilization of asthma prevalence among adolescents and increase among schoolchildren (ISAAC phases I and III) in Spain

BACKGROUND: Most studies show a steep increase in asthma prevalence in the last decades, although few studies had applied the same methodology. Recent reports point out the possibility that the epidemic has come to an end. We have studied the prevalence of asthma in a very large sample of children, repeating the study eight years apart. METHODS: Repeated cross-sectional studies using the International Study of Asthma and Allergies in Childhood (ISAAC) protocol in a sample of Spanish schoolchildren 6-7 (parent-reported) and 13-14 (self-reported) years old in 1994-95 (phase I) and 2002-2003 (phase III). The number of participants was 42 417 in phase I and 42 813 in phase III. The participation rate was over 87% (13-14 years) and 70% (6-7 years). RESULTS: The prevalence of wheezing in the previous year in children aged 13-14 years was 9.0 and 9.3% for boys and 9.6 and 9.2% for girls for phases I and III, respectively. Children 6-7 years of age showed a substantial increase in wheezing in the previous year (7.0 and 10.7% for boys and 5.3 and 8.2% for girls). Other symptoms and severity indexes followed the same patterns. CONCLUSIONS: In the last 8 years, the prevalence of asthma has not changed in 13-14-year-old Spanish children but has increased substantially in 6-7-year olds.     

First culture isolation of Borrelia lonestari, putative agent of southern tick-associated rash illness

Southern tick-associated rash illness (STARI) is a Lyme disease-like infection described in patients in the southeastern and south-central United States, where classic Lyme disease is relatively rare. STARI develops following the bite of a lone star tick (Amblyomma americanum) and is thought to be caused by infection with an "uncultivable" spirochete tentatively named Borrelia lonestari. In this study, wild lone star ticks collected from an area where B. lonestari is endemic were cocultured in an established embryonic tick cell line (ISE6). The cultures were examined by dark-field microscopy for evidence of infection, and spirochete identity and morphology were evaluated by flagellin B and 16S rRNA gene sequence, by reaction to Borrelia-wide and B. burgdorferi-specific monoclonal antibodies, and by electron microscopy. Live spirochetes were first visualized in primary culture of A. americanum ticks by dark-field microscopy 14 days after the cell culture was inoculated. The sequences of the flagellin B and 16S rRNA genes of cultured spirochetes were consistent with previously reported sequences of B. lonestari. The cultured spirochetes reacted with a Borrelia-wide flagellin antibody, but did not react with an OspA antibody specific to B. burgdorferi, by indirect fluorescent antibody testing. Electron microscopy demonstrated organisms that were free and associated with ISE6 cells, with characteristic Borrelia sp. morphology. This study describes the first successful isolation of B. lonestari in culture, providing a much needed source of organisms for the development of diagnostic assays and forming a basis for future studies investigating the role of the organism as a human disease agent.     

Profile of nursing workers with RSI/WRMD diagnosis in Salvador-Bahia in 1998-2002

This quantitative study aimed at drawing the profile of nursing workers with a confirmed RSI/WRMD diagnosis, seen at the Center of Workers' Health Studies (Cesat) in Salvador, Bahia, from 1998 to 2002. Data collection was performed based on medical reports and, complementarily, guidelines with items of interest for this investigation. Out of the medical reports, only those of nursing workers were selected. There was the identification of 79 workers--four nurses, 74 assistants, and one technician. There was a prevalence of women aged between 30 and 49, with high school and a monthly income from three to six minimum wages. Out of the total numbers, at the time of data collection, 77.22% were employed, 15.19% were unemployed, and 7.5% were retired. Among the injuries found, carpal tunnel syndrome and cervicalgia prevailed.     

Giant pleural fibroma

Solitary fibrous tumors of the pleura are uncommon mesenchymal tumors that have been reported in adults. There are very few cases in children. These tumors are considered benign but their behavior is often unpredictable because they can invade nearby structures and transform into malignant variants after several years. Their clinical presentation is diverse but generally asymptomatic and they are detected incidentally in routine radiologic studies. Prognosis depends firstly on resectability of the tumour and secondly on its size, mitotic count, polymorphism, and necrosis within the tumour. Surgical resection is usually curative. Long-term follow-up is recommended because local recurrences can occur after surgery. We report the case of an asymptomatic 15-year-old girl with a giant thoracic mass revealed incidentally on a chest radiograph. Physical examination revealed thoracic asymmetry and no sounds of breathing were found in the right lung. Computerized tomography and magnetic resonance images showed the giant size of the mass. Preoperative fine needle biopsy was performed. Intraoperative biopsy confirmed the diagnosis. Although histologically benign, the tumors may enlarge rapidly. In the present case, because of the localization and size of the tumor, the patient was at increased risk. The tumour was resected and the postoperative course was uneventful. At present our patient remains under long term annual follow-up.     

Gene conversion (655G splicing mutation) and the founder effect (Gln318Stop) contribute to the most frequent severe point mutations in congenital adrenal hyperplasia (21-hydroxylase deficiency) in the Spanish population

This study addresses the contributions of gene conversion and a founder effect to the distribution of the two most frequent severe point mutations of the 21-hydroxylase (21OH) gene causing congenital adrenal hyperplasia: the 655G splicing mutation at intron 2, and Gln318Stop in a Spanish population. Direct and indirect analyses of segregated mutant and normal 21OH genes in 200 Spanish families (classic and nonclassic 21OH deficiency) were performed. Both mechanisms were found to contribute to different degrees to the defective investigated alleles. The 655G splicing mutation (62 alleles, 15.5%) seemed to be almost exclusively related to recent conversion events, whereas Gln318Stop (33 alleles, 8.3%) is more likely to be due to the dissemination of remotely generated mutant alleles. Other severe defective alleles, 8 bp-deletion (13 alleles, 3.3%), 306insT (5 alleles, 1.3%), and gene deletions (43 alleles, 11%), as well as the mild mutation Val281Leu (120 alleles, 30%), also appear to be strongly associated with particular D6S273 alleles. Although gene conversion contributes to the generation of severe 21OH alleles, the high frequency of some severe mutations in different geographic areas is consistent with a founder effect.     

An in vivo method for adenovirus-mediated transduction of thick ascending limbs

BACKGROUND: The thick ascending limb of the loop of Henle (THAL) plays an important role in the maintenance of salt, water, and acid-base balance. While techniques for gene transfer of renal vascular cells and some tubular segments have been described, in vivo transduction of THALs has not been successful. We hypothesized that in vivo injection of adenoviral vectors into the renal medulla would result in efficient transduction of THALs. METHODS: We injected recombinant adenoviruses containing the reporter gene, green fluorescent protein (GFP), driven by either the cytomegalovirus promoter (Ad-CMVGFP) or the promoter for the Na/K/2 Cl cotransporter (Ad-NKCC2GFP), which is THAL-specific, into the outer medullary interstitium of Sprague-Dawley rat kidneys. Kidneys were removed at various times after viral injection and analyzed for GFP expression. RESULTS: Western blots revealed strong GFP expression in the outer medulla (which is composed primarily of THALs) 5 days after Ad-CMVGFP injection. We quantified THAL transduction efficiency by scoring the number of fluorescent tubules in THALs suspensions, which showed that at least 77 +/- 3% of THAL expressed GFP. To specifically transduce THALs, we injected Ad-NKCC2GFP into the medullary interstitium. As determined by Western blot, GFP expression was only detected in the outer medulla. Immunohistochemistry and confocal microscopy showed that GFP was localized to tubular cells positive for Tamm-Horsfall protein. Thus, GFP fluorescence was only detected in THALs, not in cortical, inner medulla or vascular cells. Time-course studies showed that GFP expression in THALs was measurable from 4 to 14 days, peaked at 7 days, and had returned to background levels by 21 days. CONCLUSION: This method facilitates highly efficient, THAL-specific transduction. While application of this technique for gene therapy in humans is unlikely due to the transient gene expression observed and the impossibility for repeated injections of adenoviral vectors, this method provides a valuable tool for investigators studying regulation and mechanisms of THAL ion transport and its relationship to whole-kidney physiology and pathophysiology.     

Reliability,validity and psychometric properties of the Greek translation of the Major Depression Inventory

Background  

The Major Depression Inventory (MDI) is a brief self-rating scale for the assessment of depression. It is reported to be valid because it is based on the universe of symptoms of DSM-IV and ICD-10 depression. The aim of the current preliminary study was to assess the reliability, validity and psychometric properties of the Greek translation of the MDI.