Ebola Virus RNA Stability in Human Blood and Urine in West Africa’s Environmental Conditions

We evaluated RNA stability of Ebola virus in EDTA blood and urine samples collected from infected patients and stored in West Africa’s environmental conditions. In blood, RNA was stable for at least 18 days when initial cycle threshold values were <30, but in urine, RNA degradation occurred more quickly.     

t(8;21) prior to acute leukemia

A t(8;21)(q22;q22) without blood and bone marrow invasion by immature myeloid precursor cells occurred in a patient previously treated for polycythemia vera. The presence of a molecular rearrangement confirmed that the chromosomal abnormality was identical to that observed in acute leukemia with t(8;21). This case shows that the translocation, t(8;21), may occur in myelodysplasia and suggests that it can precede the appearance of overt leukemia.     

Predictive value of retinal function by the Purkinje test in patients scheduled for cataract surgery in Kinshasa, DR Congo

AIM: To assess the retinal function in patients with dense cataracts in resource poor settings in Kinshasa, DR Congo. METHODS: In a tertiary eye care center, the Purkinje entoptic test was performed as part of the ophthalmological examination in 98 eyes in patients with cataract, using a penlight. Totally 92 cataract patients including 86 patients suffered from unilateral and 6 from bilateral cataracts were included in the study. The investigator asked the patients about their perception of the vascular pattern most commonly described as a leafless or dead tree. Visual acuity≥6/60 was considered an indication of good visual function and visual acuity<6/60 of poor function. Following small incision cataract surgery, best corrected visual acuity (BCVA) was determined and compared with the preoperative findings. RESULTS: Out of 98 eyes, there were 80 (81.6%) where the Purkinje entoptic phenomenon was reported by the patients. After cataract surgery, out of the 80 eyes, there were 75 (93.8%) with a BCVA of better than 6/60, whereas in 5 eyes (6.2%), BCVA was 6/60 or less. Out of the 18 eyes (18.4%) where no Purkinje tree was recognized, there were 14 (77.8%) with BCVA of better than 6/60, whereas in 4 (22.2%) BCVA was 6/60 or less. CONCLUSION: The Purkinje entoptic test is successfully used for preoperative assessment of retinal function in patients with dense cataract. However, further investigation and refinement of the test is necessary to validate the method for use in sub-Saharan conditions.     

Effect of endothelin blockade on pressure natriuresis in nitric oxide-deficient hypertensive rats

OBJECTIVE: Chronic inhibition of nitric oxide synthesis has been shown to cause arterial hypertension and an important blunting of the pressure diuresis and natriuresis response. The mechanisms mediating these abnormalities are not completely established. We therefore studied the effects of endothelin on these alterations. MATERIALS AND METHODS: Pressure diuretic and natriuretic relationships were evaluated in rats treated chronically (3 weeks) with the nitric oxide synthesis inhibitor N(omega)-nitro-L-arginine methyl ester (L-NAME; 40 mg/kg per day), alone or in combination with bosentan sodium salt (acute treatment: 10 mg/kg, intravenously; chronic treatment: 10 mg/kg per day). RESULTS: Chronic treatment with L-NAME significantly elevated mean arterial pressure (143.7 +/- 2.8 mmHg versus 102.8 +/- 1.6 in controls), reduced the glomerular filtration rate and renal blood flow and shifted the pressure diuretic and natriuretic responses to the right. Treatment with bosentan, either acute or chronically, did not attenuate the arterial hypertension of the L-NAME-treated rats but normalized the glomerular filtration rate and renal blood flow. In spite of the normalization of renal hemodynamics, the pressure diuretic and natriuretic responses of the bosentan-treated groups were not normalized, although chronic bosentan significantly improved the pressure natriuretic response. CONCLUSIONS: These results indicate that endothelin participates in the renal hemodynamic and excretory alterations that follow chronic inhibition of nitric oxide synthesis. However, the arterial hypertension is not mediated by endothelin activation.     

Short-term variability in arterial pressure and heart rate in man

Short-term fluctuations in blood pressure (BP) and heart rate (HR) were analysed in a group of seventeen males with essential hypertension (n = 8) or with normotension (n = 9). Indirect finger BP was measured by a Finapres device. Analog-to-digital conversion of the BP was used to determine systolic, diastolic, and mean arterial pressure and HR every s. The equidistant sampling allowed a direct spectral analysis using a fast Fourier transform algorithm. BP recordings combined low frequency plus high frequency oscillations. The presence of high frequency oscillations of SBP probably reflects fluctuations in cardiac output. HR exhibited a combination of low and high frequency oscillations, such as systolic pressure. The corresponding spectra illustrate these observations. The high frequency (respiratory) oscillation corresponded to one peak easily detected on the spectrum of SBP and/or HR. Slow waves were detected in a 4-129 mHz range and divided into a 4-66 mHz low frequency region and a 66-129 mHz mid frequency region (Mayer waves). The sum of the values of consecutive bands was calculated to represent an integrated spectrum of each series of treatment. Controlled respiration produced at rest a marked increase in the high frequency component. HR variability increased with the level of HR. This study illustrates the applicability of a spectral procedures combined to an indirect BP measurement to study short-term oscillations of BP and HR.