Ecological drivers of helminth infection patterns in the Virunga Massif mountain gorilla population.

The Virunga Massif mountain gorilla population has been periodically monitored since the early 1970s, with gradually increasing effort. The population declined drastically in the 1970s, but the numbers stabilized in the 1980s. Since then, the population has been steadily increasing within their limited habitat fragment that is surrounded by a dense human population. We examined fecal samples collected during the Virunga 2015-2016 surveys in monitored and unmonitored gorilla groups and quantified strongylid and tapeworm infections using egg counts per gram to determine environmental and host factors that shape these helminth infections. We showed that higher strongylid infections were present in gorilla groups with smaller size of the 500-m buffered minimum-convex polygon (MCP) of detected nest sites per gorilla group, but in higher gorilla densities and inhabiting vegetation types occurring at higher elevations with higher precipitation and lower temperatures. On the contrary, the impact of monitoring (habituation) was minor, detected in tapeworms and only when in the interaction with environmental variables and MCP area. Our results suggest that the Virunga mountain gorilla population may be partially regulated by strongylid nematodes at higher gorilla densities. New health challenges are probably emerging among mountain gorillas because of the success of conservation efforts, as manifested by significant increases in gorilla numbers in recent decades, but few possibilities for the population expansion due to limited amounts of habitat.

[Long-term use of prazosin alone and combined with propranolol in patients with essential hypertension]. / Dlitel'noe primenenie prazosina i ego sochetaniia s propranololom u bol'nykh gipertonicheskoi bolezn'iu.

Therapeutic efficiency and hemodynamic effects of prazosin were examined in 42 patients with essential hypertension in the course of prolonged treatment. Where the adrenoblocker showed low efficiency, the beta-blocker propranolol was added to the treatment scheme. The mechanism of the hypotensive effect was shown to be dependent on correlations between arteriolo- and venodilatation. In the presence of prevailing precapillary dilatation, BP dropped owing to reduced total and regional vascular resistance. If venodilatation was more pronounced, the hypotensive effect was due to reduced minute volume. The addition of propranolol eliminated the manifestations of sympathetic stimulation, enhanced the hypotensive effect and improved general condition of the patients. Combined treatment is indicated particularly in those cases of stable hypertension where prazosin alone has failed to produce an adequate effect.

[Clinical use of chloranolol (tobanum) in essential hypertension patients]. / Klinicheskoe primenenie khloranolola (tobanuma) u bol'nykh gipertonicheskoi bolezn'iu.

A clinical study of the efficiency of a new beta-blocker, chloranolol (Tobanum, Hungary), was carried out in 24 patients with second-stage essential hypertension. Central and intracardiac hemodynamics, left-ventricular myocardial function (echocardiography) and regional hemodynamics (occlusion plethysmography) were assessed in 14 patients before treatment and on days 10-15 and 25-30 of chloranolol administration. During the fourth or fifth week of chloranolol treatment, arterial BP diminished by 12/10% (p less than 0.01) owing to an 11.5% reduction in the cardiac index and a 15.7% reduction in heart rate (p less than 0.001), while the stroke index and total peripheral resistance showed no significant change. No basic changes in end diastolic and systolic left-ventricular size and volume, nor in the ejection fraction were seen during treatment. Myocardial contractility dropped by 9.8% (p less than 0.05), and intramyocardial tension, by 14% (p less than 0.001), while the thickness of the interventricular septum declined by 7% (p less than 0.001), and that of left-ventricular posterior wall, by 4.2% (p less than 0.005). Chloranolol treatment was particularly efficient in moderately hypertensive patients and also in some highly-hypertensive ones that had not responded to propranolol.

[Condition of the tissue oxygen regime of patients with essential hypertension with different types of hemodynamics]. / Sostoianie kislorodnogo rezhima tkanei u bol'nykh gipertonicheskoi bolezn'iu s razlichnymi tipami gemodinamiki.

Systemic and regional hemodynamic parameters were investigated using echocardiography, venous-occlusion plethysomography, and tissue oxygen regimen was studied polargraphically, in 51 patients with essential hypertension. Tissue oxygen supply becomes increasingly inadequate as the disease progresses, as reflected in limited oxygen delivery to tissues, its reduced utilization, and smaller reserve capacities of oxygen transport at the microcirculatory level. In patients with hyperkinetic circulation, increased blood stroke volume was combined with a significant increase in baseline tissue oxygen tension and the capillary-to-tissue oxygen diffusion rate, while changes in the resistive vascular element were basically functional. Changes in regional hemodynamics and tissue oxygen supply were particularly severe in patients with hypokinetic circulation.

[Treatment of hypertension with the calcium antagonist korinfar and its combination with obzidan]. / Lechenie gipertonicheskoi bolezni antagonistom kal'tsiia korinfarom i ego sochetaniem s obzidanom.

A hypotensive effect of corinfar and its effect on the indices of the central and peripheral hemodynamics were studied in 50 patients with stage II hypertension. In 3 weeks BP was lowered at the expense of a considerable decrease in the total peripheral vascular resistance (TPVR) (by 29.6%) and regional vascular resistance (by 48%). It was accompanied by an increase in the peripheral blood flow (by 61%), a reflex activation of the sympathetic-adrenal system with an increase in heart rate and cardiac output (by 22%, p less than 0.001). An index of vein distensibility remained unchanged. The addition of propranolol removed signs of the sympathetic stimulation of the cardiac activity, improved vasodilatator tolerance, enhanced a hypotensive effect of corinfar causing a transient increase in TPVR and tension of the resistive vessels only. By the end of the 4th month of therapy these indices significantly decreased. A prolonged combined therapy with corinfar and propranolol resulted in a significant decrease in the resistance of resistive vessels in maximum vasodilatation characterizing the regression of arteriole structural changes. Besides there was a decrease in the wall thickness (p less than 0.01) and left ventricular myocardial mass (by 7.88 +/- 2.66 g, p less than 0.05) that was interpreted as a tendency to a decrease in a degree of hypertrophy of the left ventricle. The efficacy of corinfar therapy was higher in the patients with hypertension with a high initial tension of the peripheral vessels.

[Venous distensibility in essential hypertension]. / Izuchenie rastiazhimosti ven u bol'nykh gipertonicheskoi bolezn'iu.

Using venous occlusive plethysmography, venous distensibility was examined in 85 hypertensive patients and in 21 normal men. Venous distensibility in the hypertensive versus normal subjects was significantly lower, being inversely depended on the blood pressure level. Venous distensibility depended directly on the blood flow in the forearm and inversely on the resistance of the resistive vessels at rest. This may indicate that the reduction of venous distensibility was caused by both functional and structural changes characteristic of both resistive and capacitance vessels. It appears that functional and structural alterations in the system of low pressure, along with an elevated resistance of the arterioles, were actively involved in changes of the peripheral resistance and the development of a hypertensive state.

[Therapeutic value of pratsiol and its effect on indicators of central and peripheral hemodynamics in patients with hypertension]. / Lechebnyi effekt pratsiola i ego vliianie na pokazateli tsentral'noi i perifericheskoi gemodinamiki u bol'nykh gipertonicheskoi bolezn'iu.

Thirty-eight patients with stage IIB essential hypertension have been studied to determine the therapeutic activity of prazosine (pratsiol, "Orion" company, Finland) and its influence on the parameters of the central and peripheral hemodynamics. It has been established that following the oral administration of the drug, a hypotensive effect develops in 90-120 min and lasts for about six h. After a three-week course of treatment, the arterial pressure in the majority of patients decreased due to a reduction in the total peripheral resistance and the tone of the resistant vessels (arterioles). Simultaneously, there was an increase in the heart rate, end diastolic and stroke volumes and in the cardiac output. In a smaller portion of patients, the arterial pressure decreased due to the predominant reduction in the venous tone; the elasticity of the veins increased sharply, the end diastolic stroke and minute volumes diminished. The heart rate and total peripheral resistance showed no statistically significant changes. It has been established that pratsiol acts as an arterial and venous vasodilator and that it is advisable to use the drug in combination with beta-blockers and diuretics.