Effects of acute renal denervation on kidney function in deoxycorticosterone acetate-hypertensive swine.

Deoxycorticosterone acetate-induced hypertension in Yucatan miniature swine appears to involve elevated peripheral sympathetic activity. Abnormalities in renal function in these hypertensive animals are also apparent. To determine the extent to which renal nerve activity controls kidney function in animals with established deoxycorticosterone acetate hypertension, the effects of acute renal surgical denervation were assessed in five normal and 10 deoxycorticosterone acetate-treated swine. After 12 to 16 weeks of treatment, mean arterial pressure rose from the normal level of 110 to 120 to 164 +/- 4 mm Hg but was decreased to 131 +/- 4 mm Hg by anesthesia. In the normal animals, blood pressure under anesthesia was 114 +/- 9 mm Hg. Acute left kidney surgical denervation significantly decreased renal vascular resistance and increased renal blood flow, glomerular filtration rate, urine flow, and sodium excretion only in the treated animals. In an additional group of six normal and eight deoxycorticosterone acetate-treated swine, the responses to renal pharmacological denervation with intrarenal guanethidine were evaluated. Guanethidine had no significant effect on renal blood flow, vascular resistance, glomerular filtration rate, urine flow, or sodium excretion in the normal animals. In contrast, in the mineralocorticoid-hypertensive animals, guanethidine significantly decreased renal vascular resistance and caused a diuresis and natriuresis with no change in glomerular filtration rate. We conclude that, in deoxycorticosterone acetate-treated miniature swine with established hypertension, renal nerve activity appears to be elevated and important in determining renal hemodynamics and sodium and water excretion.

Effects of aspirin treatment on kidney function in exercising man.

The effects of aspirin treatment on kidney excretory function were investigated in treadmill-exercised men. Six individuals ran for 30 min at 70% of their maximal oxygen consumption. Exercise tests were conducted for control and aspirin-treated conditions. Aspirin (3.25 g/d) was administered for 3 d prior to testing. Experiments were carried out with the subjects non-hydrated and hydrated (4 ml H2O/kg body weight). Aspirin treatment did not influence the alterations in creatinine clearance, urine volume, osmolar clearance, and/or sodium and potassium excretion seen with exercise. The only effect of aspirin was observed in the recovery samples of the non-hydrated tests in which aspirin treatment significantly decreased urine volume and increased urine specific gravity, osmolality, and the urine/plasma osmolality ratio. These results suggest that aspirin treatment does not have any significant effects on the renal excretory response to short-term moderate exercise.

Oxygen consumption in treadmill-exercised Yucatan miniature swine.

Oxygen consumption was measured in Yucatan miniature swine during various intensities of treadmill exercise. Nine animals were evaluated at rest and at various treadmill velocities ranging from 2.5-4.5 mph. Oxygen consumption was linearly related to treadmill speed during sub-maximal exercise work loads (r = 0.92, P less than 0.01). Maximal oxygen consumption was also determined in two groups of animals. In one group (N = 6) the highest attainable oxygen consumption was 24.0 +/- 1.31 ml . min-1 . kg-1. In the second group (N = 9) an electric prod was utilized to encourage the animals to run. Their maximal oxygen consumptions ranged from 33.9-51.1 ml . min-1 . kg-1 with a mean of 41.7 +/- 1.8 ml . min-1 . kg-1. These data indicated that Yucatan swine have a relatively low aerobic capacity compared to the rat or dog, but their oxygen consumptions are similar to that observed in untrained man.

Basic pharmacokinetics and the potential effect of physical therapy interventions on pharmacokinetic variables.

Pharmacokinetics involves the factors that influence drug absorption, distribution, and elimination. Pharmacokinetic variables determine how a specific dose of a drug will eventually reach target tissues and exert a response. Various factors can influence normal pharmacokinetics, including exercise, application of physical agents, and massage. These interventions produce hemodynamic and other physiologic changes that can potentially alter drug disposition within the body. The magnitude and specific type of pharmacokinetic changes, however, are highly variable depending on the specific intervention and the drug in question. Physical therapy interventions seem to have the greatest potential to affect absorption and distribution of drugs that are administered by transdermal techniques or by subcutaneous and intramuscular injections. Research is needed to determine exactly how physical therapy interventions can affect the pharmacokinetics of various medications, and how the clinical effects of these medications are affected by altered drug disposition.

Current trends in cardiovascular pharmacology.

To help resolve abnormalities in cardiovascular function, many different types of drugs have been developed. Only recently, however, has there been increased emphasis on determining flow these agents decrease morbidity and mortality. In some cases, standard drug therapy has been challenged somewhat by newer drugs or new applications of existing drugs that seem to provide better outcomes in terms of disease progression and survival. The purpose of this article is to provide an update on contemporary pharmacologic management of three common conditions: hypertension, congestive heart failure, and myocardial ischemia/infarction. Physical therapists should be aware of the rationale for using specific drugs in each condition and that these medications can have positive therapeutic effects and adverse side effects that can influence the patient's response to physical therapy.

Effects of ultrasound and trolamine salicylate phonophoresis on delayed-onset muscle soreness.

The purpose of this study was to determine the effects of ultrasound and phonophoresis using an anti-inflammatory-analgesic cream (trolamine salicylate) on delayed-onset muscle soreness (DOMS). Repeated eccentric contractions were used to induce DOMS in the elbow flexors of 40 college-aged women. Subjects were then assigned randomly to one of four groups: (1) group 1 (n = 10) received sham ultrasound using placebo cream, (2) group 2 (n = 10) received sham ultrasound using trolamine salicylate cream, (3) group 3 (n = 10) received ultrasound using placebo cream, and (4) group 4 (n = 10) received ultrasound using trolamine salicylate cream. Subjects were treated on 3 consecutive days. Muscle soreness and active elbow range of motion were assessed daily prior to each treatment. The subjects in group 3 experienced an increase in DOMS, whereas no increase in soreness was observed in the subjects in group 4. The authors concluded that ultrasound enhanced the development of DOMS but that this enhancement was offset by the anti-inflammatory-analgesic action of salicylate phonophoresis. These findings suggest that salicylate phonophoresis may be useful in clinical situations in which it is desirable to administer ultrasound without increasing inflammation.

Environmental pollution effects on reproductive health - clinical-epidemiological study in southern Italy.

UNLABELLED: This study aims to address the clinical, statistical and Epidemiological Relationship Between Birth Defects and Environmental Pollution, in the Campania Region and in Salerno. OBJECTIVES: WE EXAMINED FOUR GROUPS OF SUBJECTS AS FOLLOWS: a sample of pregnant women living in Salerno, a sample of pregnant women living in highly polluted areas, a sample of controls, pregnant women and residents out of the Campania Region, considered in unpolluted areas (Foggia) and in the Salerno area. METHODOLOGIES: a toxicological and genetic analysis was conducted on patients examined. CONCLUSIONS: there is an epidemiological link between environmental pollution and reproductive health in the Salerno area. Experimentally there are the first evidences of endocrine disruptors by the PCB. It has been inferred an overexpression of the mir-191 as a marker of pollution by dioxin-like compounds. Socially, correct information of populations at risk is necessary and a possible preventive and ongoing medical care must be ensured.

Induction of recurrent experimental allergic encephalomyelitis with myelin basic protein.

Recurrent experimental allergic encephalomyelitis (EAE) was induced in Lewis rats by inoculation of human myelin basic protein (MBP) and complete Freund's adjuvant (CFA). The animals developed clinical disease characterized by unsteadiness, ataxic gait, and abnormal posturing of the limbs. Spontaneous remissions and relapses were noted for periods up to 120 days. Histologically there were perivascular infiltrates of mononuclear cells, especially prominent in the cerebellar white matter. There was little evidence of demyelination. This study demonstrates that relapsing EAE may be induced with MBP in the rat. Sensitization with other myelin antigens is not required, although immunity to such antigens may be necessary to induce demyelination. It is postulated that relapsing EAE may be associated with a defect in suppressor cell function.

Effects of prostaglandin inhibition on renal function in deoxycorticosterone-acetate hypertensive Yucatan miniature swine.

This study evaluated the effect of prostaglandin (PG) on renal function in normal and deoxycorticosterone-acetate (DOCA) hypertensive Yucatan miniature swine. Eight animals were implanted with DOCA impregnated silicone strips. MAP increased in the conscious DOCA animals from a normal pressure of 110-115 mmHg, to 148 +/- 4 mmHg. After 3-4 weeks, the DOCA hypertensive and eight normal (sham or non-implanted) animals were anesthetized with sodium pentobarbital which reduced MAP in the DOCA pigs to normotensive levels. Under anesthesia, PG inhibition (indomethacin or meclofenamate, 2 mg/kg i.v.) increased MAP only in the normal group (P less than .05). PG inhibition caused a significant reduction in renal blood flow in both groups, but only decreased glomerular filtration rate in the DOCA animals (P less than .05). Radioactive microsphere distribution to the other cortex of the normal animals was significantly decreased with PG inhibition, (P less than .05). No consistent changes in electrolyte excretion or urine flow rate was seen in either group following PG inhibition. These data indicate that PG may influence renal hemodynamics in both normal and DOCA hypertensive Yucatan miniature swine. The finding that PG inhibition selectively decreases GFR in the DOCA animals suggests a possible protective role of these hormones in this hypertensive animal model.

Effects of phenoxybenzamine, metoprolol, captopril, and meclofenamate on cardiovascular function in deoxycorticosterone acetate hypertensive Yucatan miniature swine.

Eight adult Yucatan miniature swine were implanted with deoxycorticosterone acetate (DOCA) impregnated silicone strips (100 mg X kg-1). After 16 weeks of DOCA treatment mean arterial pressure (MAP) increased to 183 +/- 4 mmHg (1 mmHg = 133.322 Pa). In four normal animals arterial pressure was 126 +/- 8 mmHg. The increase in MAP in the DOCA animals was due to an elevated total peripheral resistance (TPR) with cardiac output remaining normal. In tests with conscious animals, phenoxybenzamine (1 mg X kg-1) significantly decreased arterial pressure via a selective decrease in TPR. Neither meclofenamate, metoprolol, nor captopril affected MAP in these DOCA hypertensive animals. Dose--response curves to exogenous norepinephrine and angiotensin II revealed that the DOCA animals had an increased pressor sensitivity to both of these agents. These data suggest that in the DOCA hypertensive Yucatan swine an increase in alpha adrenergic activity and (or) an increase in smooth muscle responsiveness to circulating catecholamines is responsible for the increase in blood pressure as a result of an increase in total peripheral resistance.

Effects of aortic constriction and renal denervation in DOCA-hypertensive swine.

The autoregulation of renal blood flow (RBF) and glomerular filtration rate (GFR) was examined in normal and deoxycorticosterone acetate (DOCA)-hypertensive Yucatan miniature swine (YMS). Aortic constriction (AC) was used to vary renal perfusion pressure (RPP) from 158 to 90 mmHg for DOCA-YMS and 124 to 50 mmHg for normals. DOCA animals had calculated RBF autoregulatory indexes demonstrating less effective autoregulation compared with controls. Over the pressure range of RBF autoregulation, control animals also autoregulated their GFR, whereas most DOCA animals did not. When renal function in DOCA-YMS was evaluated at the normotensive RPP of 115 mmHg, GFR, urine volume, and sodium excretion were decreased by approximately 60, 70, and 80%, respectively. In DOCA-YMS, after the normalization of RPP to 115 mmHg, renal denervation significantly increased RBF. In DOCA animals the relative decrease in sodium and water excretion in relation to decreased RPP was not altered by renal denervation. In this hypertensive model the excretion of water and sodium are closely linked to RPP. At a normotensive RPP the sodium retention in the DOCA animals may be even further exaggerated by their inability to autoregulate GFR.

The role of the sympathetic nervous system in 2-kidney DOCA-hypertensive Yucatan miniature swine.

To assess the mechanism responsible for maintaining the elevated arterial pressure in 2-kidney DOCA treated Yucatan miniature swine, cardiovascular parameters and the responses to hexamethonium bromide (HMB) were evaluated in normal and DOCA treated animals. Using chronically instrumented conscious animals, measurements of mean arterial pressure (MAP), cardiac output (CO), and calculated total peripheral resistance (TPR) revealed that with DOCA hypertension MAP was increased 50-60 mmHg above controls. This increased pressure was due to an increase in TPR with CO remaining normal. HMB normalized the MAP of the DOCA animals via a selective lowering of TPR to a value similar to that of the controls. In DOCA hypertensive animals these functional changes, due to increased peripheral sympathetic nerve activity, were reflected by significantly elevated plasma norepinephrine. In this animal DOCA administration produces a neurogenic form of hypertension which appears to be analogous to essential hypertension in man.

Anterior versus posterior walkers: a gait analysis study.

Eight children, who needed walkers to ambulate and who were able to use either anterior or posterior walkers, were selected for a comparative study of both types of walker. Data for gait analysis, using high-speed cinematography, were collected to determine stride length, time in double support and velocity. Trunk, hip and knee angles were also measured during four phases of the gait cycle. The results demonstrated significant improvements in both postural alignment and gait characteristics with the posterior walker.