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Biomedical subjects

R Rossi

Publications and source records attributed to R Rossi.

At least 325 records · Page 18Linked to original sources
PubMed1992

Circadian patterns of drinking and eating in pygmy goats.

The eating and drinking patterns of pygmy goats fed ad lib and kept on a 12 h light/12 h dark cycle were recorded and analyzed. Eighty-four percent of drafts (drinking bouts) were associated with meals (feeding bouts). Only 42% of meals were associated with drafts. In the light phase meals associated with drafts were significantly larger than meals not associated with drafts, suggesting that meal size is increased by water intake around meals. Cumulative food intake was positively correlated with cumulative water intake, but the correlation was weaker during the dark phase than during the light phase. The results demonstrate that water intake in ruminants is associated with food intake, but the link between water and food intake seems to be more pronounced during the light phase than during the dark phase.

Animals↗
PubMed1992

Functional analysis of the pertussis toxin promoter.

The expression of the pertussis toxin ptx operon is positively regulated in cis by a promoter region of about 170 base pairs and in trans by the bvg locus, which codes for the transcriptional activator protein BvgA. The promoter contains two direct repeats which are essential for its activity. When the position of these direct repeats relative to the transcription start point was changed, the activity of the promoter was strongly impaired. The repeated sequences therefore do not represent enhancer-like elements similar to those which have been identified in other positively regulated promoters; instead, the integrity of the whole promoter region seems to be an important feature of ptx regulation. A transcription interference assay was carried out to analyze in vivo binding of regulatory proteins to the ptx promoter. The results suggest that the direct repeats are the recognition sequence of a protein, which binds to them only under conditions in which the promoter is activated. In vitro DNA binding experiments with BvgA protein purified from an overproducing Escherichia coli strain were performed. However, no binding of BvgA to the ptx promoter was observed under conditions where binding of BvgA to the fha and bvg promoters occurred. This suggests that factors in addition to the bvg system are involved in the regulation of the Bordetella virulence regulon.

Bordetella pertussis↗
PubMed1992

Bone mass status in different degrees of chronic renal failure.

Bone mineral density (BMD) was evaluated in 69 patients with chronic renal failure (CRF) and in healthy controls matched for age, sex, and, for women, menopausal status. Both appendicular (predominantly cortical) and axial (predominantly trabecular) bone mass were measured. Appendicular BMD was measured by single photon absorptiometry on the distal forearm and axial BMD was measured by dual photon absorptiometry on the lumbar spine. Patients were divided into three groups on the basis of creatinine clearance: group 1, 58 to 36 ml/min; group 2, 30 to 18 ml/min; group 3, 15 to 9 ml/min. Both appendicular and axial BMD decreased with the worsening of renal failure. Parathyroid hormone levels were inversely correlated with the values of appendicular BMD. BMD values were significantly lower in postmenopausal than in premenopausal women. Months of menopause were inversely correlated with axial BMD values. Appendicular BMD was lower in CRF patients than in controls, and both appendicular and axial BMD were significantly lower in postmenopausal uremic women than in postmenopausal healthy women.

Absorptiometry, Photon↗
PubMed1992

Circadian rhythm of calcitonin gene-related peptide in uncomplicated essential hypertension.

OBJECTIVE: To assess the existence of an altered circulating pattern of calcitonin gene-related peptide (CGRP) in hypertension. DESIGN: The 24 h variation in plasma CGRP was measured and compared in 10 patients affected by uncomplicated essential hypertension and in nine age- and sex-matched healthy volunteers. The diurnal variations in blood pressure, atrial natriuretic peptide (ANP), plasma renin activity (PRA), plasma aldosterone and plasma cortisol were also assessed. METHODS: Recumbency studies were performed under standardized, drug-free conditions beginning at 0800 h. Venous samples were drawn every 4 h for 24 h and hormone levels were assessed with specific radioimmunoassays. The blood pressure was measured every 15 min with a SpaceLabs 90207 monitor. RESULTS: The mean 24-h plasma CGRP concentrations were significantly lower in the hypertensive group than in the control group. In both groups a circadian rhythm was present with the same pattern, but at a lower level in hypertension. A temporal sequence starting with the nocturnal rise in plasma CGRP concentrations and progressing with the elevations of ANP, PRA, and plasma aldosterone and cortisol was apparent in both groups. The nocturnal rise in the CGRP and ANP concentrations coincided with the blood pressure and the heart rate falls. CONCLUSIONS: Our data show that CGRP is lower than normal but maintains its circadian variability and its relationship with the diurnal variations in blood pressure and other hormones known to be active on the cardiovascular system.

Adult↗
PubMed1992

Effect of endothelin 1 on plasma glucose and lipid levels in pygmy goats.

The effect of endothelin 1, a recently discovered vasoconstrictor hormone, on levels of plasma glucose and lipids was investigated in pygmy goats. Endothelin 1 was injected intraperitoneally (1.72 micrograms/kg BW) and blood samples were taken by puncturing the jugular vein immediately before and 60, 150 and 240 min post injection. Endothelin 1 in comparison to vehicle significantly increased plasma glucose and FFA levels, whereas plasma triglycerides were significantly reduced. Thus, beside its vasoconstrictive action, endothelin 1 also has metabolic effects. Whether these effects are directly caused by endothelin 1 or whether they are due to a release of a metabolic hormone, e.g. epinephrine, remains to be investigated.

Animals↗
PubMed1992

delta-Opioid receptors and the secretion of growth hormone in man: effect of opioid delta-receptor agonist deltorphin on GH responses to GH-releasing hormone and insulin-induced hypoglycemia.

To investigate the role of delta-opioid receptors in the modulation of growth hormone (GH) secretion, we compared in normal subjects the effect of the highly selective delta-opioid receptor agonist Deltorphin (DT) on the GH secretion responses to pituitary (GH-releasing hormone, GHRH)- and hypothalamic (insulin-induced hypoglycemia, IIH)-mediated stimuli. DT blunted the GH response to IIH, whereas it had no effect on the GH response to GHRH. It is concluded that in man DT-induced activation of delta-opioid receptors exerts an inhibitory action on hypoglycemia-stimulated GH secretion. Based on the lack of an effect of DT on the GH response to GHRH, we suggest that DT may modulate the secretion of GH through suprapituitary mechanisms.

Adult↗
PubMed1992

Bilateral and simultaneous inferior petrosal sinus sampling in the early diagnosis of an ACTH-producing pituitary microadenoma and its detection by magnetic resonance one year later.

This study describes a case of pituitary-dependent Cushing's syndrome where standard biochemical and radiological techniques were discordant in localizing the origin of the autonomous adrenocorticotropic hormone (ACTH) hypersecretion in the pituitary. Hormonal evaluation suggested a pituitary genesis for the disease, but both sellar computed tomography and cranial magnetic resonance (MR) were unable to give clear-cut evidence for a pituitary neoplasm. Simultaneous and bilateral inferior petrosal sinus sampling (SBIPS) correctly identified the left side of the pituitary gland as the source of autonomous ACTH production. One year later, the shaded signs of a pituitary lesion in the left side of the gland were seen with MR imaging, and a 0.5-cm in height adenoma was surgically removed. At the 2-year follow-up the patient's symptoms had completely disappeared, and her menses were restored. In this case, SBIPS correctly diagnosed the presence of an ACTH-secreting pituitary microadenoma one year before shaded signs of the pituitary lesion appeared with MR imaging. This is a clear-cut demonstration of the accuracy of the SBIPS technique in localizing small pituitary lesions.

Adenoma↗
PubMed1992

Effect of deltorphin on pituitary-adrenal response to insulin-induced hypoglycemia and ovine corticotropin-releasing hormone in healthy man.

To determine the role of delta-opioid receptors in the modulation of hypothalamic-pituitary-adrenal activity, we studied in normal subjects the effect of the highly selective delta-opioid receptor agonist deltorphin (DT) on the secretion of ACTH, cortisol, and arginine vasopressin in response to insulin-induced hypoglycemia. In an attempt to clarify the site of opiate modulation of ACTH secretion, we also studied in normal subjects the effect of DT on the ACTH response to ovine CRH-41. DT blunted the ACTH, cortisol, and arginine vasopressin responses to insulin-induced hypoglycemia, whereas it had no effect on the ACTH and cortisol responses to CRH. We conclude that DT-induced activation of delta-opioid receptors exerts an inhibitory influence on hypoglycemia-stimulated ACTH secretion. Based on the lack of an effect of DT on the ACTH response to CRH, we postulate that DT may modulate the secretion of ACTH through suprapituitary mechanisms.

Adrenocorticotropic Hormone↗
PubMed1992

The ultrastructure of the capsule surrounding Pomphorhynchus laevis (Acanthocephala) in its intermediate host Echinogammarus stammeri (Amphipoda).

The capsule or the membranous layer surrounding larvae of Pomphorhynchus laevis Müller, 1776 in its intermediate host, Echinogammarus stammeri S. Karaman, 1931, was studied by electron microscopy. Some observations were also made with a light microscope. Capsule components mainly show a tubular profile; capsule thickness can reach up to 8 microns. In some instances, within the hemocoel of E. stammeri, the parasite was encapsulated by amphipod hemocytes.

Acanthocephala↗
PubMed1992

Hypervolemic pulmonary edema and severe coagulopathy after intrauterine dextran instillation.

A healthy young woman with recurrent spontaneous abortion and septate uterus underwent hysteroscopic metroplasty with intracavitary instillation of 1350 mL of 10% dextran 40 in normal saline. After the operation, the patient developed acute hypervolemic pulmonary edema and severe coagulopathy due to temporary impairment of platelet function. Fluid overload, which could have been caused by the hyperosmolar properties of dextran, worsened progressively as fluids were drawn from the interstitial space and urine output was reduced. The use of a dilute and/or low-molecular-weight dextran solution to distend the uterine cavity during operative hysteroscopy is not without risk of complications.

Acute Disease↗
PubMed1992

[Warthin's tumor of the parotid. The signs of a case].

The authors report a case of Warthin's tumor associated with cat scratch disease placed in 2 nodes. Both arose at the same time and evolved rapidly. Diagnosis was made by histology after their removal. We underline the rarity of the pathology, the frequent diagnosis made after operation and recommend enuclouresection of neoplasm as the first choice, considering the benignity of the lesion and the modest aggression allowed.

Adenolymphoma↗
PubMed1992

[Long-term surgical prognosis of aortic valve diseases with pulmonary hypertension. Apropos of 34 cases].

Thirty-four patients underwent isolated aortic valve replacement with mean pulmonary artery pressures greater than 40 mmHg between 1972 and 1988. The aortic valve disease was stenotic in 10 cases, regurgitant in 14 cases and mixed in 10 cases. Thirty patients (88%) had invalidating cardiac failure (NYHA Classes III and IV). The mean preoperative ejection fraction was 44 +/- 15%. The hospital mortality was 17.6%. Ten patients died secondarily, five with terminal cardiac failure. The 5 year actuarial survival was 70 +/- 16%; the 10 year survival was 60 +/- 18% with an average follow-up of 115 +/- 61 months. None of the patients was lost to follow-up. Fifteen of the 18 survivors (83%) are asymptomatic or pauci-symptomatic after a follow-up of 126 +/- 62 months. Doppler echocardiography (n = 12) showed normal prosthetic valve function in 11 cases and aortic regurgitation in 1 case. Eight patients had tricuspid regurgitation with pulmonary artery systolic pressures less than 30 mmHg in 6 cases and between 30 and 40 mmHg in 2 cases. Severe pulmonary hypertension is therefore a poor early postoperative prognostic factor in aortic valve replacement surgery due to the associated left ventricular dysfunction. However, the long-term results are satisfactory: clinical improvement is usually related to a reduction of pulmonary hypertension.

Actuarial Analysis↗
PubMed1992

MS2/Cardio: towards a multi-service medical software for cardiology.

Many clinics are interested to use software packages in daily practice, but lack of integration of such packages seriously limits their scope. In practice this often entails switching between programs and interrupting the run of an individual program. A multi-task approach would not solve this problem as it would not eliminate the need to input the same data many times, as often occurs when using separate packages. The construction of a Multi-Service Medical Software package (MSx2) is described, which was also developed as an example of practical integration of some clinically relevant functions. The package runs on a personal computer in an MS-DOS environment and integrates a time-oriented medical record management unit (TOMRU) for data of ambulatory patients, and a drug information management unit (DIMU) concerning posology, content, effects, and possible interactions. Of the possible database configurations allowed by MSx2, the cardiology patient database (MSx2/C) and hypertensive patient database (MSx2/H) were developed and described here. Clinical information to be included in the configurations was obtained after discussion and consensus of clinical practitioners. MSx2/C was distributed to several hundred clinical centers during computerized courses to train future users. MSx2 can easily transfer patient data to statistical processing packages.

Ambulatory Care Information Systems↗
PubMed1991

[Creation of a colostomy using a circular mechanical stapler].

The paper describes the method used to create a preternatural anus in terminal stomas using a mechanical circular stapler (Model EEA-31). Two methods are put forward: Chung's and Burke's methods (the latter of which was used by our department). A mechanical circular stapler has been used several times (13) to perform this type of stoma, with excellent esthetic and functional results, both immediate and long-term. It was only necessary to reoperate in one case in order to suspend the affected colic loop.

Colostomy↗