Enteroviruses as a possible cause of hypertension,dilated cardiomyopathy (DCM) and hypertensive heart failure (HHF) in South western Nigeria

Background

Human enteroviruses have long been associated with various diseases of man resulting into a wide range of acute symptoms involving the cardiac and skeletal muscles, central nervous system, pancreas, skin and mucous membranes.

Objective

To assess the role of enteroviruses in the etiology of hypertension, DCM and HHF.

Methods

We obtained stool specimens from 70 subjects comprising 65 patients and 5 controls and isolation was carried out on RD, L20B, HEp-2C and Vero cell lines and identified by neutralization with standard antisera (RIVM). Thirty-six enteroviruses were isolated and identified to be Coxsackieviruses-B5, A9, Echoviruses 1, 6, 7, 9, 11, 12, 22, 30 and Poliovirus type 1 and 3.

Results

Three most frequently occurring enterovirus serotypes which constitute 60.0% of the 30 NPEV typed and 50.0% of all the isolates were Echoviruses, Coxsackie-B5-virus and Coxsackievirus-A9. Echoviruses constituted 50.0% of all the serotypes while Coxsackieviruses-B5 and A9 accounts for the 27.8 % and 5.6% respectively. Enteroviral isolation rate was higher in age groups 51 years and above. The percentage of study subjects who had Coxsackie-B5-viruses and echoviruses was significantly (P<0.05) higher in cases of hypertension, HHF and DCM than in control subjects. Coxackie-B5-virus, Echovirus-6 and Echovirus-11 were found in both study locations.

Conclusion

The findings of this study showed that Enteroviruses may likely be involved in the etiology of hypertension, DCM and HHF. Further studies would therefore be necessary for the prevention and control of these diseases.     

Membrane protein interactions in sickle red blood cells: evidence of abnormal protein 3 function

The pattern of membrane abnormalities in sickle red blood cells suggests that sickle hemoglobin damages membrane proteins. We have previously shown a functional defect in sickle ankyrin, poor spectrin- binding ability. Here we examine the other major binding interactions of sickle membrane proteins including spectrin self-association, binding of ankyrin and protein 4.1 to protein 3, and the formation of the spectrin-actin-protein 4.1 complex. We found that sickle spectrin was normal in self-association and ability to participate in the spectrin-actin-protein 4.1 complex. Sickle protein 4.1 bound normally to protein 3 and formed normal complexes with actin and spectrin, even when sickle spectrin was used. The only major abnormality we found was a reduced ability of sickle protein 3 to bind ankyrin. This functional defect could not be explained experimentally on the basis of cysteine modification or enhanced tyrosine phosphorylation. We conclude that damage of sickle membrane proteins is not a diffuse scattershot process, but is largely confined to regions near membrane-associated hemoglobin, the spectrin-binding domain of ankyrin and the ankyrin- binding domain of protein 3. The mechanism and consequences of this damage continues to be investigated.     

Effect of <Emphasis Type="Italic">Citrullus vulgaris</Emphasis> on some functional indices of selected tissues of Wistar rats

Citrullus vulgaris (watermelon) is a fruit with prophylactic and therapeutic potentials. In an attempt to maximize these potentials, the seed and rind are now often consumed together with the pulp. This study aimed at evaluating the implications of such consumption. Study involved the use of 35 Wistar rats grouped into seven with a control group administered distilled water, and the other groups administered varying concentrations of the pulp and whole fruit for 28 days. Alanine and aspartate aminotransferase (ALT, AST) were assayed in the serum and liver. Total protein of the serum and selected tissues was determined and malondialdehyde (MDA) level measured. Phytochemical screening revealed the presence of steroids, saponin, alkaloids, flavonoids, and terpenoids in both whole fruit and pulp. Significant increases (p < 0.05) were seen in the liver ALT levels while there was a decreased (p < 0.05) intestinal total protein in the treatment groups. No significant (p ? 0.05) difference was seen in the serum and pancreas MDA levels while an increased (p < 0.05) intestinal MDA level was observed. Increased liver ALT levels in all the treatment groups might be due to high glutamate levels of C. vulgaris. Decreased (p ? 0.05) intestinal total protein might be indicative of protein loss, while elevated (p < 0.05) intestinal MDA levels in the groups administered whole fruit is suggestive of a defect in absorption at the intestinal epithelium. Hence, whole fruit consumption of C. vulgaris should be done with caution as it has potential to cause intestinal oxidative stress.     

Endothelialization of Nonapposed Stent Struts Located over the Origin of a Side Branch: Results with Different Carbofilm-Coated Stents

Objective: To evaluate the degree of endothelialization of the nonapposed struts located at the ostia of side branches.
Background: Endothelialization of coronary stents has got considerable relevance because of the phenomenon of late thrombosis. Bifurcation location and incomplete stent apposition have been linked to this complication.
Methods: Domestic pigs (n = 11; weight: 25 ± 3 kg) were anesthetized and had one stent per coronary artery implanted: one stainless steel (Tecnic^®), one cobalt-chromium (Chrono^®), and one tacrolimus-eluting stent (Janus^®), all of them being Carbofilm^®-coated (Sorin). One, three, or seven days postprocedure, the pigs were sacrificed, the hearts explanted, and longitudinal sections examined by surface electron microscopy to quantify the percentage of the strut endothelialized over the branches and in the total surface.
Results: Forty-four side branches (25 stents) that had stent struts over their origin were evaluated. Different patterns of endothelialization were observed, from the total absence to the complete endothelialization. There were no significant differences in relation to type of stent or to the artery treated. The predictors of higher percentage of endothelialization were the ratio of metal to branch diameter (P = 0.04) and better endothelialization in the rest of the stent (P = 0.0002), only this parameter maintaining significant correlation (P = 0.03) in multivariate analysis.
Conclusions: Carbofilm^®-coated stent struts located over the origin of side branches follow the pattern of endothelialization for the rest of the stent, even in the case of tacrolimus-eluting stent.     

3-Methylcholanthrene and benzo(a)pyrene modulate cardiac cytochrome P450 gene expression and arachidonic acid metabolism in male Sprague Dawley rats

Background and purpose:

There is a strong correlation between cytochrome P450 (P450)-dependent arachidonic acid metabolism and the pathogenesis of cardiac hypertrophy. Several aryl hydrocarbon receptor (AhR) ligands were found to alter P450-dependent arachidonic acid metabolism. Here, we have investigated the effect of 3-methylcholanthrene (3-MC) and benzo(a)pyrene (BaP), two AhR ligands, on the development of cardiac hypertrophy.

Experimental approach:

Male Sprague Dawley rats were injected (i.p.) daily with either 3-MC (10 mg·kg⁻¹) or BaP (20 mg·kg⁻¹) for 7 days. Then hearts were removed, and the heart to body weight ratio and the gene expression of the hypertrophic markers and P450 genes were determined. Levels of arachidonic acid metabolites were determined by liquid chromatography-electron spray ionization-mass spectrometry.

Key results:

Both 3-MC and BaP increased the heart to body weight ratio as well as the hypertrophic markers, atrial natriuretic peptide and brain natriuretic peptide. 3-MC and BaP treatment increased the gene expression of CYP1A1, CYP1B1, CYP2E1, CYP4F4, CYP4F5 and soluble epoxide hydrolase. Both 3-MC and BaP treatments increased the dihydroxyeicosatrienoic acids (DHETs) : epoxyeicosatrienoic acids (EETs) ratio and the 20-hydroxyeicosatetraenoic acid (20-HETE) : total EETs ratio. Treatment with benzo(e)pyrene, an isomer of BaP that is a poor ligand for the AhR, did not induce cardiac hypertrophy in rats, confirming the role of AhR in the development of cardiac hypertrophy. Treatment with the ω-hydroxylase inhibitor, HET0016, significantly reversed BaP-induced cardiac hypertrophy.

Conclusions and implications:

3-MC and BaP induce cardiac hypertrophy by increasing the ratio of DHETs : EETs and/or the ratio of 20-HETE : total EETs, through increasing soluble epoxide hydrolase activity.     

The crown-rump length in early human pregnancy: a reappraisal

Summary. The crown-rump length (CRL) was measured by means of transvaginal sonography in 41 pregnancies resulting from in-vitro fertilization (IVF). The embryonic CRL could be determined as early as 25 days after follicle aspiration. A reference chart was constructed relating the CRL to the number of days following follicle aspiration. Comparison with the CRL chart by Robinson & Fleming (1975) currently in use revealed that transvaginal sonography allows earlier and more accurate measurement of embryonic CRL.     

The Effect of Sodium Depletion and Potassium Supplementation on Vasopressin,Renin and Catecholamines in Hypertensive Men

ABSTRACT Seventeen 50-year-old hypertensive men (157±4/110±2 mmHg, mean ± SE) were given low sodium diet for one week, which was supplemented with potassium the following week. The urinary Na⁺/K⁺ excretion ratio changed from 2:1 to 1:5 and 1:12, respectively, during dietary intervention. Arterial plasma vasopressin decreased by 3.4±1.7 ng/l (0.05>p<0.10) and urinary excretion of vasopressin was reduced by nearly 50% (p<0.001) during sodium depletion, while plasma noradrenaline increased by 38% (p<0.001) and plasma dopamine showed an increase by 58% (p<0.001). Plasma renin concentration increased four-fold during sodium depletion (p<0.001). With combined salt depletion and potassium supplementation, arterial plasma vasopressin decreased by 9.5±4.0 ng/l (p<0.05) compared to control. Urinary excretion of vasopressin together with plasma noradrenaline and dopamine were unchanged during the second week. The reduction of blood pressure was most marked during the first week (143±3/103±2 mmHg, p<0.05), but continued to fall also during the second week. Thus, during sodium restriction in middle-aged hypertensive men, blood pressure reduction occurs concomitantly with inhibited vasopressin release, despite enhanced renin and catecholamine release. Potassium supplementation during sodium restriction induces only minor changes in these variables.     

DEFECT IN BILE ACID CONCENTRATING ABILITY OF THE GALLBLADDER IN CONGENITAL CHLORIDE DIARRHOEA

Abstract. Bakkeren, J., Monnens, L. and van Os, C. (Departments of Paediatrics and Physiology, University of Nijmegen, Nijmegen, The Netherlands). Defect in bile acid concentrating ability of the gallbladder in congenital chloride diarrhoea. Acta Paediatr Scand, 70:43, 1981.–Congenital chloride diarrhoea is assumed to be caused by a defect in the coupled NaCl influx mechanism in the ileum. As a similar coupled NaCl transport mechanism has been postulated in the gallbladder, the concentrating ability of the gallbladder was studied in a patient with congenital chloride diarrhoea. Bile acid concentrations were measured in the duodenal fluid before and after stimulation of gallbladder contraction by cholecysto-kinin. In the chloride-diarrhoea patient no increase in bile acid concentration was established after cholecystokinin injection, in contrast to a pronounced increase in three control children, suggesting that the absorption of salt and water by the gallbladder may be disturbed in the patient. The results support the postulated similarity of the NaCl transport mechanisms in the ileum and gallbladder. In congenital chloride diarrhoea one defect in a NaCl transport protein could explain the disturbances in electrolyte absorption.