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Biomedical subjects

F Strollo

Publications and source records attributed to F Strollo.

At least 37 records · Page 2Linked to original sources
PubMed1998

Outcome results of the Fosinopril Versus Amlodipine Cardiovascular Events Randomized Trial (FACET) in patients with hypertension and NIDDM.

OBJECTIVE: ACE inhibitors and calcium antagonists may favorably affect serum lipids and glucose metabolism. The primary aim of the Fosinopril Versus Amlodipine Cardiovascular Events Randomized Trial (FACET) was to compare the effects of fosinopril and amlodipine on serum lipids and diabetes control in NIDDM patients with hypertension. Prospectively defined cardiovascular events were assessed as secondary outcomes. RESEARCH DESIGN AND METHODS: Inclusion criteria included a diagnosis of NIDDM and hypertension (systolic blood pressure of > 140 mmHg or diastolic blood pressure of > 90 mmHg). Exclusion criteria included a history of coronary heart disease or stroke, serum creatinine > 1.5 mg/dl, albuminuria > 40 micrograms/min, and use of lipid-lowering drugs, aspirin, or antihypertensive agents other than beta-blockers or diuretics. A total of 380 hypertensive diabetics were randomly assigned to open-label fosinopril (20 mg/day) or amlodipine (10 mg/day) and followed for up to 3.5 years. If blood pressure was not controlled, the other study drug was added. RESULTS: Both treatments were effective in lowering blood pressure. At the end of follow-up, between the two groups there was no significant difference in total serum cholesterol, HDL cholesterol, HbA1c, fasting serum glucose, or plasma insulin. The patients receiving fosinopril had a significantly lower risk of the combined outcome of acute myocardial infarction, stroke, or hospitalized angina than those receiving amlodipine (14/189 vs. 27/191; hazards ratio = 0.49, 95% CI = 0.26-0.95). CONCLUSIONS: Fosinopril and amlodipine had similar effects on biochemical measures, but the patients randomized to fosinopril had a significantly lower risk of major vascular events, compared with the patients randomized to amlodipine.

Amlodipine↗
PubMed1998

The effect of microgravity on testicular androgen secretion.

BACKGROUND: Spaceflight causes a number of physiological changes in the human body. Most would consider space travel to be a stressful event even for well-trained astronauts. Should this be true, pituitary gonadotrophins (mainly LH) and testicular androgens, like testosterone (T), should decrease inflight in male astronauts. We therefore hypothesized that lowered testicular androgen levels might occur in men during spaceflight, due to stress-dependent lowered LH concentrations. METHODS: In order to test this hypothesis, on different day pre-, in- and postflight we assayed wake-time salivary and urinary T in four astronauts, as well as wake-time plasma levels of adrenocorticotropin (ACTH), cortisol (CS), LH, T and its peripherally active metabolite 3-alpha-diol glucuronide (3ADG). In order to compare clinical to subjective data, all 7 male crewmembers anonymously answered a daily questionnaire from pre- to postflight asking them to self-rate sexual drive and potency, muscle strength and mood. RESULTS: Salivary, urinary and plasma T, as well as 3ADG, decreased during flight, while LH unexpectedly increased inflight (p < 0.05). A parallel decrease in sexual drive was observed (p < 0.05). A dramatic recovery of salivary T was found on R + 1. CONCLUSIONS: This was the first time that spaceflight was demonstrated to cause temporary, still dramatic hypoandrogenism which was not due to blunted pituitary gonadotrophin secretion. The cause for hypoandrogenism is unknown but it may depend on fluid shift affecting testicular function or androgen distribution in various body compartments.

Adult↗
PubMed1998

Indirect evidence of CNS adrenergic pathways activation during spaceflight.

BACKGROUND: Microgravity causes cephalad fluid shift and compensatory mechanisms. Hormonal changes suggestive of peripheral sympathetic (catecholaminergic) nervous system activation have been recently found in astronauts during flight. Simulation studies showed increased perivascular sympathetic fiber density in the rat brain. HYPOTHESIS: Intracranial microcirculatory adaptations might also occur in astronauts, involving an increase in the turnover rate of catecholamines, i.e., norepinephrine (NE) and its precursor, Dopamine (DA). DA is known to inhibit prolactin (PRL) release and to enhance growth hormone (GH) secretion by the pituitary. Therefore, increased brain dopaminergic activity would result into lower circulating PRL concentrations. At the same time, plasma levels of GH and of its effector insulin-like growth factor-1 (IGF-1) would increase during flight. METHODS: Circulating cortisol (CS), PRL, GH and IGF-1 levels were measured 2 d preflight, inflight (4-5 d after launch) and on different days postflight in four astronauts involved in the Spacelab D-2 mission. RESULTS: No significant changes were found in CS concentrations. PRL decreased while GH and IGF-1 increased inflight (p < 0.05). After flight no statistically relevant hormonal changes were found with respect to preflight. CONCLUSION: The observed hormonal changes were consistent with the original hypothesis that spaceflight might activate CNS adrenergic pathways. They occurred in the absence of two typical markers of stress, namely CS and PRL increase, thus ruling out any non-specific effect of acute stress on the results. In agreement with the most recent results of real and simulated microgravity studies performed in both the experimental animal and in man, these data lend support to the hypothesis that the CNS adrenergic pathways are also activated in the human during spaceflight.

Adaptation, Physiological↗
PubMed1997

Changes in human adrenal and gonadal function onboard Spacelab.

Astronauts have to face chronic stress during the mission period. This might cause: (i) increased adrenocortico-trophin (ACTH) and cortisol (Cort) secretion; (ii) impaired luteinizing hormone (LH) output with consequent testosterone (T) hyposecretion in men. Moreover, should the subjects prove not to synchronize their inner clocks to the time shift protocols defined by NASA, most results would be questionable. The aim of this study was to verify if plasma testicular androgens were lower than baseline and Cort biorhythm was preserved in male astronauts during a short duration flight.

Adrenocorticotropic Hormone↗
PubMed1996

Hormonal, water balance, and electrolyte changes during sixty-day confinement.

The EXEMSI experiment has made it clear that it is difficult to perform psychological and physiological protocols satisfactorily in the same study. It is, therefore, essential that the objectives of study be defined clearly before the start. While behavioral and psychological studies may be possible and provide valid results for a small group of mixed gender, it is more difficult to conduct valid physiological studies due to large differences between individuals and even in the same individual over time. As stated before, it is unusual in space research on humans and even during space simulation studies to have large and homogeneous groups of subjects. The consequence is that the results remain tentative. For a better understanding of the physiological data collected during the ISEMSI ad EXEMSI experiments, they should be correlated with the results of the psychological studies. One of the conclusions drawn from the ISEMSI experiment was that confinement provides a valuable parallel to other simulations of weightlessness, such as bedrest. The same pattern of changes in parameters like the blood volume regulating hormones renin and aldosterone was observed as in bedrest. After the EXEMSI study we can say that the conditions imposed by confinement, high work load, and stress, potentiate these effects. This implies that in using head-down bedrest as a weightlessness simulation the confinement effects must be identified by setting adequate control conditions for the head-down position, for short-term as well as for long-term simulations. Indeed, we have seen in the two isolation studies that confinement may have its effects at the beginning of the isolation period (EXEMSI) as well as during the entire isolation period (ISEMSI). In planning for EXEMSI we wanted to obtain more insight in some of the phenomena observed during ISEMSI by the introduction of new techniques such as the doubly labeled water method for determination of total body water. However, in some cases the opposite effects of those encountered in ISEMSI were found. This was probably due to the many changes in the experimental scenario, like number of subjects, mixed gender, living space per subject, and workload. Thus, for future isolation studies the operational scenario should be better examined and preferably standardized. Nevertheless, in such studies as well as in long-term sojourns in a space station, the crew size will not be larger than that of the EXEMSI crew. Physiologists will, therefore, have to become familiar with the study of small groups of subjects and to try to overcome the problems of large individual differences and statistical analysis of data from small groups.

Adult↗
PubMed1995

Amenorrhea in gonadal dysgenesis, caused by chromosomal translocation.

A healthy 23-year-old woman with amenorrhea was examined at the Mendel Institute. She had been amenorrheic for 4 years, and had not responded to hormone treatment. We therefore decided to study her family tree and karyotype. We describe the results of our study here: the patient was found to have gonadal dysgenesis, caused by translocation of a fragment of the X to a 12 chromosome, resulting from a break at q21, at the end of the q-arm.

Adult↗
PubMed1995

Renal and endocrine responses in humans to isotonic saline infusion during microgravity.

It was the purpose of this study to investigate how the endocrine and renal mechanisms of fluid volume control in humans (n = 4) adapt to microgravity by applying an intravenous isotonic saline infusion. The acute ground-based supine (Sup) and seated (Seat) positions were chosen as references. During microgravity, renal sodium excretion (UNaV) was doubled during the second and third hours after infusion compared with during Seat (P < 0.05) but blunted during the first hour after infusion compared with during Sup, leading to a reduction in cumulative UNaV (59 +/- 15 vs. 108 +/- 12 mmol/5 h; P < 0.05). Plasma norepinephrine (NE) attained the highest value 3 h after infusion during microgravity (31 +/- 5 x 10(-2) ng/ml vs. 19 +/- 1 and 13 +/- 3 x 10(-2) ng/ml for Seat and Sup, respectively; P < 0.05). Inflight levels of plasma renin and aldosterone were very similar to levels during Seat. In conclusion, 1) the microgravity-adapted renal responses to infusion reflected a condition in between that of ground-based Seat and Sup, respectively, and 2) the plasma levels of NE, renin, and aldosterone were elevated inflight and not related to the changes in UNaV and urinary flow rate. These observations are in contrast to results of ground-based simulation experiments and might partly have been caused by a prior inflight reduction in extracellular fluid volume. The high levels of NE during microgravity warrant further investigation.

Adult↗
PubMed1995

Hormonal regulation during a 60-day confinement (ESA-EXEMSI'92) in humans.

EXEMSI'92 was a 60-day isolation and confinement experiment with an international crew. During this second experiment of the European Space Agency (the first one was a 28-day confinement with 6 men: ISEMSI'90), blood volume regulating hormones and water balance were studied. During ISEMSI'90, stress level was elevated as shown by specific markers and we observed some interesting results which have been already observed before, during bed-rest experiments. Thus, our conclusion was that some of the physiological effects observed during bed rest could be the consequence of the "confinement effect" and/or stress imposed to the subjects during such experiments. The aim of the present physiological study was: 1/to define the origin of the blood pressure increase seen during ISEMSI'90; 2/ to study the blood volume regulating hormones (ANP, renin, aldosterone) variations; 3/ to determine the dehydration level by measuring the total body water with the doubly labeled water (DLW) method and fluid balance in general.

Aldosterone↗
PubMed1992

Effects of an acute saline infusion on fluid and electrolyte metabolism in humans.

Several hormonal systems participating in body fluid and electrolyte homeostasis were investigated in six healthy volunteers in a supine body position during a period of 9 days and nights. Under strictly controlled conditions, striking circadian rhythms were observed for plasma levels of vasopressin, renin, aldosterone, guanosine 3',5'-cyclic monophosphate, cortisol, and epinephrine. Nocturnal decreases and diurnal increases in urine flow rate and urinary excretion of electrolytes were observed and closely paralleled the urinary excretion of urodilatin. During 48 h after an acute isotonic saline infusion (2 liters within 25 min) and after a 48-h control experiment the urinary excretion of H2O and electrolytes, and simultaneously the alterations in endocrine systems participating in body fluid homeostasis, were determined. Urine flow and urinary electrolyte excretion rates were significantly increased during 2 days after the saline infusion. The largest increase in urinary fluid and electrolyte excretion was observed between 3 and 22 h postinfusion. These long-term changes were paralleled by altered H2O and Na balances and also by elevated body weights that returned to baseline values with an approximate half-life of 7 h. These data suggest that vasopressin, atrial natriuretic peptide, and catecholamines are unlikely to be of major importance for the renal response to this hypervolemic stimulus. The renin-aldosterone system was suppressed during 2 days postinfusion. This suppression correlated with the effects of saline load on Na excretion. However, the closest relation with Na excretion was observed for the kidney-derived member of the atrial natriuretic peptide family, urodilatin, which was considerably increased during the long-term period up to 22 h postinfusion. Thus these data show that the human body in supine position requires approximately 2 days to regulate the amount of Na and H2O provided by an acute saline infusion. The data also suggest that urodilatin and the renin-aldosterone system might participate in the long-term renal response to an acute saline infusion and also in the mediation of circadian urinary excretion rhythms.

Adult↗
PubMed1990

Hormonal changes after parabolic flight: implications on the development of motion sickness.

Twenty-two different humoral parameters including stress-, gastrointestinal- and volume-regulating hormones were measured before and within 45 min after parabolic flight maneuvers of twenty healthy adult subjects. We compared hormonal data of motion sickness-affected participants with those unaffected. Changes in cortisol and vasoactive intestinal peptide plasma levels were significantly different (p less than 0.002 and p less than 0.004) between the two groups with increasing plasma levels of both hormones during motion sickness but decreasing levels within the control group. Growth hormone and prolactin plasma levels increased by 400% and 115% within the motion sickness-affected group and to a smaller degree (120% and 40% increases, respectively) within the control group, while ACTH levels were almost unchanged within both groups. Pancreatic polypeptide and gastrin plasma levels as well as plasma levels of insulin and C-peptide were significantly decreased within both groups after the parabolic flight. Plasma renin, aldosterone, atrial natriuretic peptide and cyclic GMP levels were unchanged within the control group. Within the motion sickness-affected group, plasma renin and aldosterone levels were decreased and atrial natriuretic peptide levels increased after the flight. Humoral parameters of the thyroid gland were neither changed within the groups nor different between the groups. The present data confirm previous results that increases in plasma levels of certain stress hormones participate in motion sickness. Furthermore, increases in vasoactive intestinal peptide levels participate in motion sickness. These increases could explain some of the gastrointestinal symptoms in motion sickness and might serve as markers for a discrimination between regular stress and motion sickness.

Female↗
PubMed1989

Right colonic hemangioma diagnosed by scintigraphy with 99-mTc sucralfate. A case report.

99-mTc-SF gastrointestinal scintigraphy used in recent years in the assessment of site and activity for ulcerative lesions, was shown to be very important for the diagnosis of a rare case of right colonic hemangioma. A young female patient suffering for some time from functional intestinal disorders, following negative radiologic and endoscopic findings, underwent 99-mTc-SF scintigraphy, which showed massive uptake of radioactivity in the ascending and right flexure of colon. A repeated colonoscopy with biopsy allowed the histologic diagnosis of capillary hemangioma.

Adult↗
PubMed1988

Thyrotropin-releasing hormone enhances event-related brain potentials and growth hormone release in man.

Changes in contingent negative variation (CNV), a brain-evoked potential related in arousal, as well as in serum triiodothyronine (T3), thyroxine (T4), thyroid-stimulating hormone (TSH), prolactin (PRL), cortisol and growth hormone (GH) levels were recorded in 12 male volunteers receiving either thyrotropin-releasing hormone (TRH) or saline infusion. Only during TRH administration an increase in CNV (P less than 0.02) and, 30 min later, in GH (P less than 0.05) occurred; thyroid hormones and PRL increased as well, in the absence of any correlation with CNV areas. Cortisol was not affected by TRH. As dopamine (DA) agonistic drugs notoriously increase both CNV areas and GH levels and experimental evidence for prodopaminergic properties of TRH has accumulated in animal models, a possible explanation of the results here presented might be the activation of DA pathways by TRH also in the human.

Adult↗
PubMed1982

[Effect of acute intravenous administration of thyroliberin on circulating reverse-T3].

Some of the Authors previously demonstrated a significant precocious serum T3 increase after 200 micrograms TRH acute intravenous administration (TRH test). Reverse-T3 (rT3) is now known to interfere with T4 conversion to T3. We therefore compared spontaneously occurring to TRH test-induced changes in T3 and rT3 serum levels within a group of four healthy women in fertile age. Maximum rT3 increase during TRH test did not differ significantly from the maximum spontaneous variation at the same time of the day. Maximum T3 increase, on the contrary, was significantly higher than observed maximum spontaneous variation (0,81 ng/ml versus 0,39 ng/ml increase, p less than 0,01). Possible implications are discussed in the text.

Adolescent↗
PubMed1982

[Comparison between spontaneous changes in circulating triiodothyronine (T3 and reverse-T3) and those induced by acute intravenous administration of thyroliberin].

Some of the Authors had previously observed a slight-non significant decrease in T3 serum levels 10 minutes after TRH intravenous administration. On the other hand, it is now well known that reverse T3 (rT3) inhibits T4 conversion to T3. We therefore investigated the changes in T3 and rT3 serum levels within the first ten minutes of a 200 micrograms TRH test in a group of 10 healthy women in fertile age. No significant change in T3 was demonstrated. On the other hand, rT3 showed a significant-yet slight-decrease 6 minutes after TRH injection (from 0,27 to 0,21 ng/ml, p less than 0,05). Some feasible explanations for this phenomenon are given in the text.

Adolescent↗