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Biomedical subjects

G Guarnieri

Publications and source records attributed to G Guarnieri.

At least 55 records · Page 3Linked to original sources
PubMed1983

Muscle biopsy studies in chronically uremic patients: evidence for malnutrition.

Evidence for muscle protein wasting and abnormal muscle metabolism is common in uremia. Muscle DNA content is considered a reliable reference standard in normal and undernourished adults. Muscle RNA content rapidly changes during starvation and refeeding. The ratio of noncollagen alkali-soluble proteins (ASP) to DNA is considered to be an estimate of the cytoplasmic volume of a single cell, and the RNA: DNA ratio is an index of the ribosomal capacity for protein synthesis. Muscle DNA, RNA, ASP, water, and fat content were determined in muscle biopsy specimens from chronically uremic patients receiving conservative treatment (CT), maintenance hemodialysis (two centers), or CAPD. Nutrient intake was low and the anthropometric indices were decreased in all groups of patients, except in the hemodialysis patients from one center. Serum proteins and muscle ASP: DNA and RNA: DNA ratios were decreased. The nutritional status was reassessed in some malnourished CAPD patients after about one year of careful nutritional advice and was unchanged. These results suggest that chronically uremic patients on CT are often malnourished, primarily because of an inadequate protein and/or energy intake. Muscle nucleic acid and protein content are useful tools for nutritional assessment at a cellular level in humans with chronic renal failure and can be used to monitor the response to nutritional therapy.

Adult↗
PubMed1982

The effects of the gabaergic drug, sodium valproate, on prolactin secretion in normal and hyperprolactinemic subjects.

To find out whether the gamma-aminobutyric acid (GABA)ergic system affects PRL secretion in humans, sodium valproate (DPA or Na-dipropyl-acetate), a drug inducing increase of endogenous GABA, was administered to 20 normal and 15 hyperprolactinemic subjects. PRL circulating levels were measured by RIA in the samples obtained after acute oral treatment with 400 mg DPA. A significant decrease (P less than 0.01) in comparison with basal levels was observed in normal women from 30-180 min after drug administration. DPA treatment also lowered blood PRL levels in hyperprolactinemic subjects (seven females) without evidence of pituitary tumor. A decrease very similar to the one found in normal subjects (P less than 0.05 vs. basal levels) was observed within 180 min from drug ingestion. Conversely, no significant changes were found after the same treatment in hyperprolactinemic patients with evidence of prolactinoma (seven females and one male). Taken together, these data seem to demonstrate that pharmacological enhancement of endogenous GABAergic tone is followed by inhibition of PRL secretion. They also suggest that GABA may exert an inhibitory control on PRL release in humans. In hyperprolactinemic subjects, this GABAergic control appears to be present only when a pituitary tumor cannot be demonstrated.

Adenoma↗
PubMed1981

Inhibitory effect of the dopamine agonist bromocriptine on the postcastration gonadotrophin rise in women.

Basal or stimulated gonadotrophin plasma levels were measured after bilateral ovariectomy in untreated and bromocriptine (BCT)-treated normal women. BCT was orally administered from the 7th to the 14th day after ovariectomy at a dose of 3.75 mg/day. BCT significantly (P less than 0.05) inhibited LH release, both basally and after LRF stimulation. Plasma FSH levels were also reduced in treated subjects, but this decrease did not reach statistical significance relative to controls. The blunted postcastration gonadotrophin rise found with BCT administration suggests that pituitary gonadotropin secretion is, in part, under dopaminergic inhibitory control.

Adult↗
PubMed1980

Simple methods for nutritional assessment in hemodialyzed patients.

Uremic patients undergoing hemodialysis are often catabolic and malnourished. To treat malnutrition effectively, a preliminary nutritional assessment is needed. Available techniques should enable the clinician to readily detect the presence of malnutrition and to follow the response to nutritional therapy. In a group of chronic uremic patients undergoing maintenance hemodialysis, the authors evaluated the nutritional status with the following indices: 1) assessment of the somatic fat and protein compartments by means of anthropometric measurements (weight/height ratio, triceps and subscapular skinfold thickness, and arm muscle circumference); 2) assessment of the visceral protein compartment (serum total protein, albumin, transferrin, pseudocholinesterase, C3, and immunoglobulin content); 3) assessment of cell-mediated immunity by means of skin tests ("skin window," PPD and phytohemagglutinin) and blood lymphocyte content; and 4) assessment of the dietary intake of nutrients with dietary diaries. Anthropometric indices, serum protein content (except immunoglobulins), and the immune response was generally lower than in normal subjects, suggesting a mixed marasmus-like and kwashiorkor-like pattern of protein-calorie malnutrition. The protein intake was normal, whereas the energy intake tended to be low. Protein intake was significantly correlated with the predialysis serum urea nitrogen. Due to the difficulties in improving oral energy intake and the negative nitrogen balance reported during the days of dialysis therapy, patients were given intravenous supplements of essential or essential and nonessential amino acids for 2 months. The effects of this short-term supplementation were limited.

Adult↗
PubMed1975

Response of plasma lipid fractions to the administration of exogenous phospholipids.

Plasma lipidic fractions (total lipids, free and total cholesterol, triglycerides, total phospholipids and low density lipoproteins) of 16 hyperlipemic subjects have been followed up over a 4-week period. Intravenous injection of exogenous phospholipids prepared from pig heart resulted in a significant decrease of all the examined lipidic fractions. The possible mechanims of exogenous phospholipids action is discussed.

Adolescent↗
PubMedDate not supplied

Dose-related effects of gamma-amino beta-hydroxy butyric acid (GABOB) infusion on growth hormone secretion in normal women.

The effect of gamma-amino beta-hydroxy butyric acid (GABOB) infusion on GH secretion has been investigated in 3 groups of 6 normal women. Different doses (100 mg/min, 20 mg/min, 3.5 mg/min) of GABOB diluted with normal saline solution were infused iv over a 20 min period and compared with control tests performed using only saline solution. The infusions with GABOB at the doses of 100 mg/min and 20 mg/min were followed by a significant rise (p less than 0.01) in GH plasma levels, in comparison to control tests. The quantitative GH secretion after 100 mg/min GABOB infusion was significantly greater (p less than 0.05) in comparison with quantitative GH secretion after 20 mg/min GABOB infusion. After 3.5 mg/min infusion, only 3 out of 6 subjects showed an increase in the hormone concentrations. The acute injection with sulpiride (5 mg iv, bolus), performed either before or after the start of GABOB infusion, failed to affect GH response to GABOB. These results show that GABOB infusion induce a dose-dependent rise in GH plasma levels in normal women. The dopaminergic system does not seem to be involved in this effect.

Adult↗
PubMedDate not supplied

Use of alkaline rinsing solution to prevent hypersensitivity reactions during hemodialysis: data from a multicentre retrospective analysis.

BACKGROUND: Hypersensitivity reactions (HSRs) can be enhanced by contact phase system activation leading to bradykinin (BK) generation. In patients treated with angiotensin converting enzyme inhibitors (ACE-I), an impaired kinin degradation can magnify the phenomenon. We have previously demonstrated that the electronegative charge of the dialysis membrane (e.g. AN69) and other cofactors including diluted blood buffer power promote BK generation, and that kallikrein synthesis on diluted plasma may be inhibited by keeping the pH value above 7.4. Our in vitro and ex vivo studies have demonstrated that the use of an alkaline solution to rinse both filter fluid compartments before their clinical use can inhibit the activation of mediators that are likely to be involved in HSRs. METHODS: The present study was aimed at gathering data from a multicenter retrospective analysis of HSRs in 15 Italian centers, with special attention to the precautions chosen to avoid recurrence, and at evaluating whether a rinsing procedure maintaining the pH of the diluted blood above 7.4 may prevent further HSRs. RESULTS: HSRs were reported in 54 patients on dialysis treatment between January 1995 and June 1997. 39/54 HSRs occurred when AN69 was used. In 44.4% of cases, HSRs were associated with ACE-I treatments. The HSR prevention modalities varied considerably among the centers. Two thirds of the nephrologists did not change their dialysis prescription but tried to modify the acidic environment of the patient's diluted blood at the first contact with the dialysis device using an alkaline rinsing procedure (BioPrime with alkaline solution). In other cases ACE-I withdrawal or a change of dialysis membrane was adopted. Thirty-six patients who received alkaline rinsing of the filters were monitored for a total of 686 months (median 17.6 months/patient) to control HSR recurrences. None of the patients enrolled in this study developed new episodes of HSRs. CONCLUSIONS: Even if considered with the caution called for by this kind of study, which was retrospective and uncontrolled, our data suggest a protective effect of the alkaline rinsing procedure with buffered solutions in the development of HSRs.

Anaphylaxis↗