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.     

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)...     

Anatomical and functional outcomes in contusion injuries of posterior segment

Purpose

To evaluate the clinical features, and anatomical and visual outcomes in patients with closed-globe contusion injury involving the posterior segment.

Methods

Retrospective review of posterior segment contusion injuries admitted to our tertiary referral center.

Results

In all, 115 patients (115 eyes) with complete data were reviewed. Surgery had been performed in 79 (69%) patients. The mean follow-up period was 6 months (range, 2–34 months). Retinal detachment, in 31% of eyes, was the most frequently encountered posterior segment pathology. The presence of retinal detachment was associated with poor visual outcome (<20/100), (P<0.001). Coexisting (five patients, 4%) and postoperative proliferative vitreoretinopathy (PVR) (two patients, 2%) was the main cause of failure in these cases. A significant positive correlation was obtained between initial and final visual acuity levels in both the medical treatment group and the surgical treatment group (P<0.05). The presenting visual acuity of <20/400 was associated with poor visual outcome (P<0.05 for both groups). Poor visual outcome in 13 patients with successful repair of retinal detachment was due to the macular lesions and the optic atrophy.

Conclusion

Retinal detachment was the most frequently encountered posterior segment pathology subsequent to closed-globe contusion injuries. In addition to macular scarring and optic nerve damage, development of PVR has prognostic significance in these eyes.     

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.