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Biomedical subjects

R Volpi

Publications and source records attributed to R Volpi.

173 records · Page 10Linked to original sources
PubMedDate not supplied

Effect of lysine vasopressin on basal and TRH stimulated TSH and PRL release in normal men.

In order to test the possible effects of lysine vasopressin (LVP) on basal and TRH stimulated TSH and PRL release, an iv bolus of LVP (0.06 IU/kg bw) was injected alone or just before TRH (20 or 400 micrograms iv) in 18 normal male subjects. The administration of LVP modified neither the basal secretion of TSH and PRL nor the TSH and PRL release induced by 20 or 400 micrograms TRH. These data suggest that in humans, vasopressin is not involved in the control of TSH and PRL release at the anterior pituitary level.

Adult↗
PubMedDate not supplied

Intravenously infused substance P enhances basal and growth hormone (GH) releasing hormone-stimulated GH secretion in normal men.

The effect of synthetic substance P (SP), infused intravenously (IV) in doses of 0.5, 1, or 1.5 pmol/kg-1/min-1 over 60 min, on GH secretion was evaluated in seven healthy men. Substance P tests and a control test with normal saline were randomly performed at weekly intervals. No untoward side effects or changes in blood pressure were observed during SP infusions. Serum GH concentrations did not change when normal saline, the lowest dose, or the middle dose of SP were infused. In contrast, GH levels rose significantly when the highest dose of SP was given, with a mean peak two times higher than baseline. Further studies were performed to test the possible influence of SP on the GH response to GH-RH. For this purpose, seven other healthy men were tested with GH-RH (1 micrograms/kg body weight in an IV bolus) during saline or SP (1.5 pmol/Kg-1/min-1 x 60 min) infusion. The GH-RH induced a significant GH rise, with a mean peak seven times higher than baseline. When subjects were infused with SP, the GH response to GH-RH was greatly enhanced, with a mean peak 12 times higher than baseline. These results demonstrate for the first time in humans that the systemic infusion of SP stimulates GH secretion, and suggest that SP might interact with GH-RH in the stimulation of GH secretion.

Adult↗
PubMedDate not supplied

Peripheral blood abnormalities in Alzheimer disease: evidence for early endothelial dysfunction.

Clinical and epidemiologic studies demonstrate that vascular risk factors may be involved in Alzheimer disease (AD). To evaluate whether vascular abnormalities are an early feature of AD, several parameters of coagulation and fibrinolysis were assessed. Thirty patients with mild AD and 30 age-matched control subjects entered the study. All subjects performed a standardized clinical and laboratory protocol. Persons with vascular risk factors and systemic diseases were excluded. AD patients present significant increased levels of thrombomodulin (p < 0.0001) and sE-selectin (p < 0.03). In contrast, no difference was found between the two diagnostic groups in the levels of beta-thromboglobulin, prothrombin fragment 1+2, fibrinogen, and von Willebrand factor. No other association but diagnosis was found with thrombomodulin and sE-selectin. These findings suggest that endothelial dysfunction is an early event in AD patients.

Aged↗
PubMedDate not supplied

[Heparin-induced thrombocytopenia syndrome and thrombosis in patients undergoing periodic haemodialysis].

Heparin-induced thrombocytopenia (HIT) is the most important immunological drug reaction that patients face today. Being unfractionated heparin the standard anticoagulation used in haemodialysis, acute or chronic uremic patients starting haemodialysis are at risk of developing HIT. Through the accurate description of two patients, one with chronic and the other with acute uraemia, who developed this complication at the start of haemodialysis, we compare the distinct clinical problems of haemodialysis-related HIT with the general clinical features of HIT. We report the occurrence of repeated clotting of both dialysers and catheters, as well as thrombosis of the central veins where the catheters are placed and of the fistulas. We also report an accurate review of the literature on haemodialysis-related HIT. We have observed that HIT seems to be particularly rare in haemodialysis patients. Since newly treated haemodialysis patients are at risk of developing HIT, and most of the studies were made on long-term chronic haemodialysis patients, we assume that the syndrome is poorly documented. Our own experience on 37 haemodialysis patients who developed HIT is reported by focusing on both the clinical presentation of HIT as well as the long-term follow up of the patients. We present some considerations on the treatment options of acute HIT in uremic patients as well as on the problem of heparin re-exposure subsequent to the HIT episode, a very prominent problem in chronic haemodialysis patient.

Anticoagulants↗
PubMedDate not supplied

[Occupational asthma due to para-tert-butylphenol: case report].

In a chemical industry worker with a history of work-related breathlessness, a bronchial provocation test with para-tert-butylphenol (PTBP) elicited a dual asthmatic reaction. As far as we know, this is the first documentation of occupational asthma due to PTBP. Previously PTBP has been associated with occupational leucoderma.

Asthma↗
PubMedDate not supplied

Thyroid hormone pattern and aggressiveness. (Isolated mice compared with dominant and submissive).

The aggressiveness induced by the forced isolation of animals may be mediated by endocrine changes. The present study focuses on the possible mediation of the pituitary-thyroid axis in the mouse (Mus musculus). The blood levels of the hormone fractions examined (T4, T3 and rT3) in isolated animals showed a significant increase in comparison with the individuals which were classified from an ethological point of view as submissive, whereas in comparison with the individuals which were classified as dominant, no difference was found for T4 and rT3, but a significant increase of T3 occurred. The choice of the categories of comparison (dominant and submissive as opposed to isolated mice) derives from the hypothesis, which has already been confirmed experimentally on an etiological level, that in this species the isolated individuals are homologous to socially dominant animals as far as aggressiveness is concerned. The endocrinological results obtained in this study support this hypothesis. Thus it is concluded that, in the species under study, isolation induces pituitary-thyroid axis activation which is similar to that found in dominant individuals and at least partially responsible for the isolation aggressiveness. The mediation of the action of TRH on the central nervous system in this phenomenon is suggested as an interesting hypothesis.

Animals↗
PubMedDate not supplied

[Choleretic and cholagogic effect of sulphuric sulfate water from the springs of Tobiano in cholestasis in alcohol related liver diseases].

Twenty male alcoholics (age: 40-60 years) abstinent for 2 weeks and affected by liver steatosis with positive laboratory indexes of biliary stasis (increased levels of total and free bilirubin, gamma glutamil transpeptidase and hepatic alkaline phosphatase) were treated for 3 weeks with 500 ml/day p.o. of placebo (aqua fontis) (Group I:N. 10) or sulfureous sulfate calcic water of the "Pergoli" spring-Tabiano (Parma, Italy) (Group II: N. 10). The abovementioned laboratory indexes of biliary stasis were measured in groups I and II before and after water treatments and were compared to values obtained in 10 age-matched normal male subjects. In addition, both before and after water treatments, alcoholic patients underwent a double blind test, where individual sensations of itch were scored. Finally, in order to establish the effect of water treatments on gallbladder contraction, the bidimensional areas at maximal longitudinal and transverse diameters were echographically evaluated in alcoholics before (time 0) and 20, 40 and 60 minutes after drinking in 10 minutes a 500 ml load of placebo (Group I) or Pergoli water (Group II). The results showed a significant reduction in the measured gallbladder area in group II alcoholics, but not in patients of group I. Furthermore, three weeks of treatment with Pergoli water significantly reduced to normal total and direct bilirubin levels, the enzyme markers of biliary stasis and the subjective sensation of itch. These parameters did not change in alcoholics of group I after placebo treatment. These data demonstrate that the oral administration of sulfureous sulfate calcic water Pergoli exerts a cholagogue activity in humans. The cholagogue activity together with the wellknown choleretic effect of this water argue in favor of the possibility for its use as support treatment to the therapy of biliary stasis in alcoholism.

Adult↗