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Biomedical subjects

R Rossi

Publications and source records attributed to R Rossi.

At least 289 records · Page 16Linked to original sources
PubMed1994

Evidence that enhancement of cholinergic tone increases basal plasma levels of calcitonin gene-related peptide in normal man.

To investigate the influence of the cholinergic system on the modulation of the circulating levels of calcitonin gene-related peptide (CGRP) under basal conditions in normal man, the effects of an acetylcholinesterase inhibitor, pyridostigmine bromide, and a muscarinic receptor blocker, pirenzepine, were studied in 16 normal subjects (8 females and 8 males). Pyridostigmine (120 mg, orally) induced a significant (P < 0.01) rise in basal plasma CGRP, while it reduced systolic and diastolic blood pressure. In all subjects, pirenzepine (0.6 mg/kg, i.v. bolus) was unable to modify the basal CGRP level. In conclusion, a pharmacologically induced enhancement of cholinergic tone resulted in an increase in CGRP, whereas muscarinic receptor blockade had no effect on CGRP levels or blood pressure. Therefore, the cholinergic system seems to be involved in the control of CGRP release in man, acting as a positive modulator. However, the available data do not indicate that there is a tonic cholinergic tone responsible for CGRP secretion under physiological conditions.

Adult↗
PubMed1994

[Surgical plasty of the coronary trunks: an alternative to bypass techniques].

Between January 1991 and December 1993, surgical coronary angioplasty was performed in 12 patients with an average age of 59 years: right coronary artery (17), left main coronary artery (3) and bilateral angioplasty (2). Internal mammary or gastroepiploic artery bypass grafts were associated on another vessel in 5 patients and 1 patient also underwent aortic valve replacement. There was no early mortality (1 month), or perioperative myocardial infarction. At the 15th postoperative day, the angiographic result was satisfactory in all patients. At 6 months, exercise testing was negative in all cases (maximum load 140 +/- 20 watts). Reoperation for bypass surgery was necessary in 1 patient because of symptomatic occlusion of the left anterior descending left anterior descending artery, one year after angioplasty of the left main coronary extending to the proximal left anterior descending. With a mean postoperative follow-up of 19 +/- 7 months (6 to 31 months), all patients are asymptomatic: 5 of the 6 angioplasties controlled angiographically at 1 year were patent without any signs of progression (1 occlusion/reoperation). Surgical angioplasty of the main coronary vessels is a sure and reliable procedure: it restores physiological coronary perfusion, economises venous and arterial vessels and is no obstacle to percutaneous transluminal coronary angioplasty.

Adult↗
PubMed1994

Expression of all-trans-retinoic acid receptor RNA in human thyroid cells.

The expression of all-trans-retinoic acid receptor (RAR) RNA was investigated by Northern blot and Reverse Transcription-Polymerase Chain Reaction in tissues and primary cultures of human thyrocytes. In normal and adenomatous samples the RAR alpha RNA was expressed, whereas the expression of RAR beta and gamma was undetectable. In carcinoma samples RAR alpha RNA expression could decline, whereas the RAR beta RNA expression could become detectable. TSH and retinoic acid did not significantly modify RAR alpha mRNA levels, whereas RA caused a significant decrease in basal and TSH-induced thyroid peroxidase (TPO) mRNA levels, and a decrease in DNA synthesis. These results demonstrate that RAR alpha gene is predominantly expressed in human thyrocytes, and suggest a molecular link between this gene and the negative regulation by RA of proliferation and function of follicular cells.

Adenoma↗
PubMed1994

Calcitriol and calcium carbonate therapy in early chronic renal failure.

The aim of this study was to evaluate the effects of a combined low-dose therapy of calcitriol and calcium carbonate on bone metabolism in the early phases of chronic renal failure. A 30-month study involving 17 patients with ECRF was made: 6 months of observation were followed by 24 months of therapy (calcitriol 0.25 microgram/day plus calcium carbonate 1 g/day). The most important results were that renal function was stable throughout the study and there was an increase in calcaemia and a decrease in plasma alkaline phosphatase, plasma osteocalcin, plasma PTH and urinary hydroxyproline. We observed a progressive slowing of the rate of loss of appendicular bone density as well as a decrease of osteoblastic and osteoclastic activity and an improvement of bone mineralization. In conclusion, low doses of calcitriol plus calcium carbonate seem to improve the biochemical and bone derangements in early renal failure.

Adult↗
PubMed1994

[Effect of dopexamine in splanchnic perfusion during surgery of the abdominal aorta].

Abdominal aortic surgery has significant effects on cardiac and splanchnic perfusion. The purpose of this study was to examine the effects of dopexamine, an inodilator drug, on hemodynamic and splanchnic perfusion with measurement of gastric intramucosal pH, by the method of gastric tonometry, during abdominal aneurysm resection. Twenty-five patients undergoing excision of an aortic abdominal aneurysm were randomly divided into two groups. During aortic cross-clamping Group II patients received dopexamine infusion, at a dose of 1 microgram/kg/m, and at a dose of 0.5 micrograms/kg/m from declamping to the end of the surgery. Whereas Group I patients did not receive a dopexamine infusion. During aortic cross-clamping the intramucosal pH value decreased in Group I patients, but did not change in Group II patients. Heart rate, cardiac index, and mixed venous oxygen saturation increased significantly during dopexamine infusion, whereas systemic vascular resistance was reduced. During aortic cross-clamping dopexamine was a useful agent in improving splanchnic blood flow, cardiac index venous saturation. Also, since the drug produces dose related hemodynamic changes of rapid onset and reversibility, it is possible to interrupt the infusion before aortic declamping to avoid the decrease in the intramucosal pH value.

Aged↗
PubMed1994

Monoethylglycinexylidide production as a measure in predicting hepatic histology.

To clarify whether monoethylglycinexylidide (MEGX) production can be useful in predicting the severity of chronic liver disease, 51 subjects were enrolled in this study: 13 mild-moderate CAH (group A), 9 severe CAH (group B), 29 cirrhosis, 18 compensated and 11 decompensated disease (group C). The patients were injected with a 1 mg/Kg lidocaine bolus i.v. and serum-sampled for MEGX values (time 15, 30 and 60 minutes), determined by TDX-immunoassay. MEGX formation was significantly different (Mann-Whitney U test) in the three groups at each time interval, especially at 30 min: group A = 70.5 +/- 9.9 ng/ml (mean +/- SD); group B = 49.7 +/- 7.2; group C = 37.2 +/- 19.5 (in A vs B, p = 0.0003; in A vs C, p < 0.0001; in B vs C, p = 0.0237). The difference between compensated and decompensated cirrhosis was always significant (p = 0.0099, 0.0005, 0.0113 respectively) but between severe CAH and compensated cirrhosis it was marginal only at 15min (p = 0.0763) and absent at 30 and 60min. At 30min MEGX values > 60 suggest mild-moderate CAH, < 40 cirrhosis, < 30 decompensated cirrhosis, between 40 and 60 severe CAH or compensated cirrhosis. We are of the opinion that the MEGX test could be utilized to predict hepatic histology.

Adult↗
PubMed1994

[Anesthesia with isoflurane in air and with isoflurane and nitrous oxide].

BACKGROUND: The aim of this study is to control the depth, the quality of recovery of total inhalation isoflurane anesthesia with or without nitrous oxide. DESIGN: Controlled comparative study was carried out on 51 patients, aged 40-54 yr, ASA 1, undergoing saphenectomy, in an University Clinic. METHODS: Induction: thiopental (3.5 mg kg), atracurium (0.6 mg kg) i.v. Patients were randomly assigned to: group 1 (26 patients), 5% isoflurane in air, by mask; group 2 (25 patients), 3% isoflurane and 60% N2O, by mask. Maintenance: group 1, 2% isoflurane in air; group 2, 1.2% isoflurane and 60% N2O. During anesthesia, consciousness and analgesia level were monitored by EEG Compressed Spectral Array, and clinical signs of pain by Evans' test; arousal time evaluation by "Time to correct response test". The subjective impressions, eventual dreams and recalls were collected using a standard set of questions one hour after the end of anesthesia and 24 hours later. One hour before anesthesia and two hours after the end of surgical procedures, a psychomotor performance recovery evaluation was performed using Zazzo's "deux barrages" test. DATA ANALYSIS: Student's "t" test. RESULTS: Adequate anesthetic depth was documented in all patients. Recovery time was statistically longer in isoflurane group (group 1 16.7 sd 2.2 minutes vs 10.3 sd 1.9 minutes group 2, p < 0.01). No patient reported recalls relative to anesthetic period. Two hours after recovery no significant differences in psychomotor performance tests were recorded. CONCLUSIONS: Isoflurane anesthesia in air, in adequate concentrations, provides a sufficient level of analgesia, hypnosis, amnesia, without clinical side effects.

Adult↗
PubMed1994

[Use of ultrasonic surgery in laparoscopic cholecystectomy].

INTRODUCTION: Laparoscopic cholecystectomy now represents a valid alternative to traditional surgery in the treatment of gallstone diseases. For the past twenty years laparotomic cholecystectomy has represented the golden standard of gallstone treatment given its extremely low mortality rate (0.5%) and equally acceptable morbidity rate. Laparoscopic cholecystectomy now appears to have taken over the position of elective treatment. Sophisticated techniques, such as ultrasound scalpels make this form of surgery particularly safe. MATERIALS AND METHODS: The authors report a series of 50 patients who underwent laparoscopic cholecystectomy in which ultrasound surgery was used in 40 cases using the CUSA system. The gallbladder hilus is prepared using ultrasound manipulation following the secure identification, respect and clipping of the cystic artery and duct. DISCUSSION AND CONCLUSIONS: Laparoscopic cholecystectomy appears to be the ideal treatment for gallstone diseases. In the series reported here the use of the ultrasound scalpel allowed the gallbladder hilus to be reach skeletization, preserving the main structures and keeping the operating field clean and blood-free, without increasing operating times. The possibility of severe accidents, such as vascular lesions to the hepatic artery or vena portae, or damage to the common bile duct or other abdominal organs are reduced using this technique.

Adult↗
PubMed1993

Morphological studies of the corpus callosum by MRI in children with malformative syndromes.

A morphological analysis of the corpus callosum has been carried out in an MRI study of 34 children with malformative syndromes and 35 normal children. We used a new morphometric method based on measurement of five specific angles. Values outside the range of normality have been found in patients with malformations of the skull, including turricephaly, acrocephaly and frontonasal dysplasia. The results have confirmed the reliability of this method for study of the conformation of the corpus callosum and of its topographical relations with the other cerebral structures.

Abnormalities, Multiple↗
PubMed1993

Partial and complete de Toni-Debré-Fanconi syndrome after ifosfamide chemotherapy of childhood malignancy.

Ten out of 79 patients treated with ifosfamide (IFO) developed a complete (n = 2) or partial (n = 8) de Toni-Debré-Fanconi syndrome (RFS). All but one of these patients had been treated in addition with cisplatinum (CPL) or had undergone radiotherapy to the abdomen or nephrectomy as part of the overall treatment for malignancy. A detailed nephrological work-up of proximal tubular function showed decreased fractional phosphate and percent aminoacid reabsorption in 37.1 and 56.7% of cases, respectively, and the excretion of alpha 1-microglobulin and N-acetyl-beta-D-glucosaminidase was elevated in 44.4 and 23.5%. Glomerular function was well preserved in the majority of patients. Tubular dysfunction was confirmed by silver-stained SDS PAGE of urine which showed mostly low molecular weight proteinuria. CPL has been shown to result in renal magnesium loss and reduced glomerular filtration rate, and its toxicity clearly differs from IFO-mediated tubulopathy. Our data suggest that subclinical impairment of proximal tubular function was significantly increased by additional CPL therapy. We conclude that CPL may enhance IFO-mediated nephrotoxicity and that a substantial number of patients is at risk of developing persistent tubular dysfunction leading to metabolic bone disease.

Child↗
PubMed1993

Retinoic acid-induced decrease of DNA synthesis and peroxidase mRNA levels in human thyroid cells expressing retinoic acid receptor alpha mRNA.

In order to clarify the effect of retinoids on thyroid cell growth and function, the presence of retinoic acid receptors (RARs) and the action of retinoic acid (RA) on DNA synthesis and on thyroid peroxidase (TPO) and thyroglobulin (TGB) mRNA expression were investigated in primary cultures of human thyroid follicular cells. A time and dose-dependent reduction in 3H-thymidine (3H-thy) incorporation was found in cells exposed for 48 h to all-trans-RA up to 1 microM. A cytotoxic effect was found only with the higher dose of 50 microM. The RA-induced decrease of 3H-thy incorporation was reflected by parallel change in DNA content of cell monolayers. The inhibitory effect of 1 microM RA on 3H-thy incorporation ranged from 28.5 +/- 4.6% in normal cells to 42 +/- 3.2% in adenomatous cells. In addition, 1 microM RA significantly reduced basal and TSH-induced TPO mRNA levels in normal, goitrous and adenomatous cells, but did not alter TGB mRNA levels. Furthermore, in these cells the study of RAR alpha and beta mRNA showed the presence of two major RAR alpha mRNA transcripts of approximately 3.5 and 2.8 Kb in size, whereas RAR beta mRNA was undetectable. Overall, our data indicate that RAR alpha gene is expressed in human thyrocytes and that RA may be involved in the regulation of the human thyroid by reducing proliferation and function of follicular cells.

Adenoma↗
PubMed1993

Epithelioid leiomyoma of the breast with granular cell change: a case report.

A 42-year-old woman with an epithelioid granular cell leiomyoma of the right breast is reported. The cells were spindle to polygonal and displayed finely granular cytoplasm. The smooth muscle differentiation of this tumor was shown by the immunohistochemical positivity of the neoplastic cells with anti-alpha smooth actin and antidesmin antisera. Microfilaments with focal densities were present in the cytoplasm at an ultrastructural level. The granular cytoplasmic changes are related to a relevant number of lysosomes within the neoplastic cells.

Actin Cytoskeleton↗
PubMed1993

Mechanisms of the effects of vasopressin on plasma levels of free fatty acids and triglycerides in pygmy goats.

1. Intraperitoneal injection of vasopressin (VP, 0.4 or 0.75 microgram/kg body wt) produced a decrease in plasma free fatty acids (FFA) and an increase in plasma triglyceride (TG) levels in pygmy goats. 2. These effects were not attenuated by prior or co-injection of a vasopressin antagonist with a selective affinity to V1-receptors. 3. A vasopressin antagonist with predominant affinity to V2-receptors prevented vasopressin's effect on plasma lipid levels whereas a V2-receptor agonist did not significantly influence plasma lipids. 4. The effect of vasopressin on plasma lipids in pygmy goats therefore seems to be mediated by receptors being neither identical with V1- or V2-receptors.

Animals↗
PubMed1993

Biological activities of terthiophenes and polyynes from the Asteraceae.

We evaluated a number of terthiophenes and polyynes, from the Asteraceae, for biological activities against microorganisms, viruses, and tumor cells, with and without the aid of UVA (long wavelength ultraviolet) radiation. The terthiophenes, which represented the basic alpha-terthienyl nucleus with simple side chains, showed impressive UVA-dependent activities, some of which were superior to alpha-terthienyl itself. In contrast, the polyynes had no significant biological activity, with or without UVA. We believe that these terthiophenes would be worthwhile evaluating in animal models of infectious diseases.

Alkynes↗