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Biomedical subjects

A R Volpe

Publications and source records attributed to A R Volpe.

At least 145 records · Page 8Linked to original sources

Physiologic role of the peripheral enkephalinergic system in regulating cardiovascular homeostasis: evidence of interactions with the renin-angiotensin and kallikrein-kinin systems.

On isolated heart preparation, it was found that Leu5-Enkephalin (Leu5-ENK) did not influence the cardiac function. On the other hand, Leu5-ENK induced a specific dose-related inhibition, in the cardiac perfusate, of the activities of kininase II (KII) and angiotensin converting enzyme (ACE) (but not of kininase I-KI). Instead no detectable alterations of the above enzymatic activities with the used concentrations of Leu5-ENK were observed in vitro. This opioid also increased specifically the effects induced by some of the autacoids, related to both renin-angiotensin and kallikrein-kinin systems, on the KII and ACE activities. A specific correlation between these Leu5-ENK-induced modifications and the functional responses of the heart to the same autacoids was observed. Naloxone (NAL) and more significantly ICI 174864 (ICI) opposed or reversed the inhibitory effect of the used opioid whereas they had neither inhibitory nor synergic effect on both KII and ACE activity by themselves. The possible physiologic role of the enkephalins in regulating cardiovascular function by acting peripherally on some humoral systems through modulatory mechanism was discussed.

Animals↗

Clinical comparison of the anticalculus effect of two mouthrinses.

A three-month, double-blind clinical study was conducted to compare the effects of supragingival calculus deposits of a mouthrinse containing soluble pyrophosphate and a copolymer of methoxyethylene and maleic acid, as compared to a mouthrinse containing only soluble pyrophosphate and a placebo mouthrinse. Male and female adult subjects were stratified into three balanced groups according to baseline calculus scores obtained from a pre-test period. They received an oral prophylaxis and were assigned to the use of one of the three test mouthrinses. All subjects used a commercially available dentifrice containing 0.76% sodium monofluorophosphate in a silica base. The results from the three-month calculus examination indicated that the soluble pyrophosphate/copolymer mouthrinse reduced supragingival deposits by 31.70% (P less than 0.03), as compared to the placebo mouthrinse. The mouthrinse containing only soluble pyrophosphate did not provide a statistically significant reduction in calculus deposits, as compared to the placebo mouthrinse.

Adult↗

Effect of a dentifrice containing triclosan and a copolymer on plaque formation: a 6-week clinical study.

A 6-week, double-blind, clinical study was conducted to determine the effect on plaque formation of a dentifrice containing 0.3% triclosan and 2% of a copolymer of methoxyethylene and maleic acid as compared to a placebo dentifrice. Ninety-one male and female adult subjects with baseline Quigley-Hein Plaque Index scores of 1.5 or greater were entered into the study. Eighty-six subjects completed the entire 6 weeks of the study. Subjects were initially stratified into two balanced groups using their baseline Plaque Index score and each group was then randomly assigned to the use of one of the two test dentifrices. All subjects received an oral prophylaxis at the start of the study. Subjects were given either the triclosan/copolymer dentifrice or the placebo dentifrice and a soft-bristled toothbrush for home use and were instructed to brush their teeth twice daily (morning and evening) for 1 minute at each toothbrushing. At the end of the 2, 4 and 6 weeks' use of their assigned dentifrice, the subjects had their teeth evaluated for plaque formation. The results indicated that the group assigned to the triclosan/copolymer dentifrice had 11.89%, 11.83% and 20.01% less plaque formation after 2, 4 and 6 weeks' use of the dentifrices, respectively, than the group assigned to the placebo dentifrice. All reductions in plaque formation were statistically significant at the 97% level of confidence or greater. The effect was more pronounced on the tooth surfaces that had the heaviest plaque formation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Kininase I, kininase II and aminopeptidase levels in patients with gastrointestinal tumors.

Some indices of the kallikrein kinin system, namely kininase I (KI), kininase II or angiotensin converting enzyme (KII-ACE) and phenylalanine-arginine aminopeptidase (AP) were analyzed, to detect their levels in ten selected normal subjects and in 20 selected patients with colonic (n = 8) and gastric adenocarcinoma (n = 12). While AP and KI levels did not show differences in the groups under analysis, KII values showed a significant difference (P +/- 0.01), present since the early stages of the diseases and unrelated to the normal laboratory indices.

Adenocarcinoma↗

Urinary kallikrein and kininase activity in normal and complicated by hypertension pregnancy.

Kallikrein and kininase activities were determined in urine of 58 hospitalized pregnant patients: 15 with E.P.H. gestosis, 10 with chronic hypertension, 18 with non proteinuric pregnancy induced hypertension, 15 with no hemodynamic disease as controls. All our cases with hypertension were treated with alpha-methyl-dopa. A significant increase in urinary kininase activity was shown by only E.P.H. gestosis group vs. controls. In the same group we found a significant decrease in urinary kallikrein activity vs. controls, in contrast with the results obtained previously, perhaps because of the different measuring method. The kininase/kallikrein ratio, theoretically indicative of kinins activity, increased significantly only in the E.P.H. gestosis group.

Blood Pressure↗

Kallikrein and kininase activities excretion in newborns affected by jaundice.

In a homogeneous group of 30 newborns, aging between 10 hours--10 days, and affected by jaundice, urinary kallikrein and kininase activities were determined. The variable considered were: sex, time of life, weight and gestational age. Urinary samples were taken at the beginning and at the end of phototherapy.

Birth Weight↗

Kallikrein and kininase excretion in football players after psychophysical stress.

In eleven football players and in four football-reserve players urinary kallikrein and kininase activities were determined before and after an official match. The results showed a significant reduction of kallikrein after the match in football players when the football-reserve players were used for comparison (p less than 0.01). Kininase activity appears increased in football players after the match, but not significantly. The Kininase/Kallikrein ratio after the match resulted significantly increased in football players (p less than 0.05) and very significantly compared to the football-reserve players (p less than 0.01).

Adult↗