Abnormal renal vasodilation to an amino acid infusion in congestive heart failure: normalization by enalapril

In congestive heart failure (CHF), the neurohormonal mechanisms that cause renal vasoconstriction, particularly those depending on the renin-angiotensin system, could interfere with renal vasodilating mechanisms. To elucidate this issue, we studied the kidney response to an amino acid infusion (known to cause renal vasodilation in healthy individuals) in eight patients with CHF. We found that the amino acid infusion (0.7 mL/kg/h of a 10% solution) elicited no renal hemodynamic response, in marked contrast to healthy subjects. We next hypothesized that the renin-angiotensin system (known to be activated in heart failure) has a role in the lack of response to the amino acid infusion. To test this hypothesis, we repeated the study after two 5-mg doses of enalapril, an inhibitor of the angiotensin-converting enzyme, administered 12 hours apart. After enalapril treatment, the amino acid infusion caused a 45% increase in mean renal blood flow (RBF) from 383 +/- 55 to 557 +/- 51 mL/min at the fifth hour (P < 0.05). This normalization of the renal response to the amino acid infusion occurred without changes in cardiac output or in systemic vascular resistance. Hence, the renal fraction of the cardiac output increased during the amino acid infusion. The recovery of the renal vascular response was not accompanied by an increase in glomerular filtration rate (GFR; filtration fraction decreased), suggesting a predominant efferent arteriole dilatation. Our study shows that, in heart failure, the kidney loses its ability to increase RBF in response to an amino acid load. This lack of renal vascular response can be restored by inhibiting the renin-angiotensin system and is unrelated to changes in systemic hemodynamics.     

School based screening for hypothyroidism in Down's syndrome by dried blood spot TSH measurement.

OBJECTIVE: To determine the feasibility of annual hypothyroid screening of children with Down's syndrome by measuring thyroid stimulating hormone (TSH) on dried blood spots at school, and to describe the outcome in positive children. DESIGN: Establishment of a register of school children with Down's syndrome, and procedures for obtaining permission from parents, annual capillary blood samples, TSH measurement, and clinical assessment of children with TSH values > 10 mU/litre. SUBJECTS: All school age children with Down's syndrome within Lanarkshire and Glasgow Health Boards during 1996-7 and 1997-8. RESULTS: 200 of 214 school children with Down's syndrome were screened. Four of the unscreened children were receiving thyroxine treatment, and only 5 remained unscreened by default. 15 of the 200 children had capillary TSH > 10 mU/litre, and all but 1 had evidence of Hashimoto's thyroiditis. Seven of the 15 children started thyroxine treatment immediately, 6 with a pronounced rise in venous TSH and subnormal free thyroxine (fT4), and one with mildly raised TSH and normal fT4 but symptoms suggesting hypothyroidism. Eight children with mildly raised venous TSH and normal fT4 were left untreated; 1 year after testing positive, fT4 remained > 9 pmol/litre in all cases, but 4 children were started on thyroxine because of a rise in TSH. TSH fell in 3 of the 4 remaining children and there was a marginal rise in 1; all remain untreated. The prevalence of thyroid disease in this population is >/= 8.9%. CONCLUSION: Dried blood spot TSH measurement is effective for detecting hypothyroidism in Down's syndrome and capillary sampling is easily performed at school. The existing programme could be extended to the whole of Scotland within a few years.     

The Prevalence of Cryptosporidium spp. in Children,Taiz District,Yemen

Background

This is the first work done on cryptosporidiosis among the children in Taiz, Yemen.

Methods

A number of 712 samples were collected from children of different ages (ranging from 1 month to 12 years) from Dec 2006 to Aug 2007. The collected samples were examined by Sheather''s sugar floatation and Modified Ziehl- Neelsen stain as well as ELISA methods. The test results were statistically analyzed by SPSS software.

Results

The overall positive percentage was 43.7%. The higher incidence (36.2%) was occurred in males while the lowest incidence (32.7%) was observed in females (r=0.876; P=0.001). The correlation between infected cases and the type of drinking water was r =0.121. Among the cases examined by ELISA (92 cases), 26.1% were infected. The correlation between seropositivity and gender was r=0.652 (P=0.031).

Conclusion

Cryptosporidium spp. is a significant pathogen among children at Taiz. Fresh water supplies, education, eating habits and domestic animals are considered the main sources for transmission of cryptosporidiosis.     

B-cell lymphoproliferative disorders in children after bone marrow transplantation: radiologic manifestations

The radiographic findings in five pediatric patients in whom unregulated B-cell lymphoproliferative disorders developed following bone marrow transplantation are described. Four patients received T-cell-depleted bone marrow from mismatched donors and one received nondepleted marrow from a matched sibling donor. These disorders are similar to B-cell lymphoproliferative disorders that have been described in other immunosuppressed hosts. They are associated with Epstein-Barr virus and range from polyclonal proliferation without cytogenetic abnormalities to monoclonal lymphoma with clonal cytogenetic changes. Unlike other postallograft lymphoproliferative processes, B-cell lymphoproliferative disorders in these patients have not responded to antiviral therapy, immunologic therapy, or chemotherapy. The radiographic patterns of disease include diffuse or focal hepatic involvement; gallbladder wall thickening; and pulmonary, soft-tissue, and basal-ganglion masses. These radiologic findings are not specific and evaluation of tissue histology is required for diagnosis.     

Toll-like receptor 9 in systemic sclerosis patients: relation to modified Rodnan skin score,disease severity,and functional status

Clinical Rheumatology - The objective of this study is to assess toll-like receptor-9 (TLR9) expression in CD3-positive T lymphocytes and CD19-positive B lymphocytes in systemic sclerosis (SSc)...