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Biomedical subjects

M Rossi

Publications and source records attributed to M Rossi.

At least 523 records · Page 29Linked to original sources
PubMed1989

In vitro short-term chemosensitivity test in head and neck tumors.

A new method to test the sensitivity of human tumor cells has been developed. A suspension of mechanically dissociated tumor cells is kept in continuous incubation for 24h, in cultures with antineoplastic agents. Drug induced cell cycle perturbations are monitored by flow cytometric computer analysis and DNA distributions of the cells stained with propidium iodide are expressed in percentage. The test is used in 15 head and neck human solid tumors. The drugs tested were: VCR, EpiDx, CDDP, MTX, 5-FU, CPM, BLM. The results obtained reveal that tumor sensitivity varies independently from the stage and malignity grading. Therapeutic combinations are assigned by selecting the drugs on the basis of the individual in vitro response.

Aged↗
PubMed1989

Cross correlation of heart rate and respiration versus deep breathing. Assessment of new test of cardiac autonomic function in diabetes.

Cross correlation is a mathematical function whereby spectral analysis is used to describe the relationship between heart-rate fluctuations (256 R-R intervals) and respiration (simultaneously obtained by pneumotacograph). To assess its usefulness for testing autonomic integrity, cross correlation and deep breathing were compared in 141 diabetic subjects (aged 39 +/- 14 yr) and in 77 control subjects (aged 33 +/- 13 yr). To characterize patients, Valsalva maneuver, 30:15 ratio, tilt, and handgrip tests were performed in 96 of these patients; 23 had two or more abnormal tests (group A), 28 had one (group B), and 45 had none (group C). Sensitivity to parasympathetic withdrawal was compared in 9 control subjects (aged 26 +/- 4 yr) by four sequential 0.01-mg/kg i.v. atropine administrations. Reproducibility was compared in 11 control subjects (aged 25 +/- 2 yr) by repeating the tests four times for 2 consecutive days. Considering all 141 patients, cross correlation and deep breathing were less than 2SD of the mean of control subjects in 64 and 36 subjects, respectively. Considering patients who also performed other tests of autonomic function, cross correlation and deep breathing were less than 2SD of the mean of controls in 42 and 30 subjects, respectively (group A, 20 and 15; group B, 12 and 9; group C, 10 and 6). Cross correlation had better reproducibility than deep breathing (C.V. 10.3 vs. 30.6% at 6 breaths/min) and greater sensitivity to atropine (after the 1st injection, cross correlation and deep breathing decreased to 34.6 and 48.2% of baseline values, respectively; P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

[Transplantation of the pancreas: surgical aspects].

Based on their personal as well as international experiences, the authors describe different surgical techniques employed in pancreatic allograft related to different complications rate and patient and graft outcome. In fact, the surgical technique represents an only partially solved problem, because of the high percentage of complications dealing with the different approaches. Even though several procedures concerning either the site of implantation either the treatment of the exocrine function have been so far used, the results up to now obtained are the main limiting factor for a large clinical application of pancreatic transplantation.

Diabetic Nephropathies↗
PubMed1989

Synthesis, antibacterial activity and structure-activity relationships of N-substituted 3-methyl-4-diazo-5-pyrazolecarboxamides.

A number of N-substituted 3-methyl-4-diazo-5-pyrazolecarboxamides (IVa-p) have been synthesized and tested for their in vitro antibacterial activity. All the compounds have been assayed against several representative Gram-negative and Gram-positive bacteria, as well as against some intestinal bacterial species. Some of the 4-diazopyrazoles IVa-c have shown a quite interesting broad-spectrum activity, while they are ineffective against the "protective" intestinal flora. The structure-activity relationships of the series have been studied quantitatively, via both univariate and multivariate methods: the results are consistent and permit some rationalization of the behaviour of the compounds investigated.

Anti-Bacterial Agents↗
PubMed1989

[Use of activated charcoal plasmafiltration in the treatment of hyperthyroidism].

We evaluated the use of activated charcoal plasmaperfusion in four patients already treated with synthetic antithyroid agents affected by severe hyperthyroid. Our patients showed no significant side-effect and a rapid improvement of their symptoms. Thyroid hormone levels were 30% lower after the procedure, but returned to previous levels after 7-10 days. Activated charcoal plasmaperfusion may represent a useful therapeutic adjunct to antithyroid drugs in patients affected by severe hyperthyroidism or thyrotoxic storm.

Adult↗
PubMed1989

Near-ultraviolet circular dichroism of bovine high molecular weight alpha-crystallin.

High molecular weight (HMW) alpha-crystallin isolated from cow nucleus has a molecular weight greater than 5 x 10(6) Daltons. Its particle dimensions have been reported to be over 500 nm. It is derived mainly from low molecular weight (LMW) alpha-crystallin. The conformational change as LMW alpha-crystallin is converted into HMW alpha-crystallin was studied by near-ultraviolet circular dichroism (NUV-CD). The main concern in measuring CD for protein aggregates with particle dimensions as high as HMW alpha-crystallin and with an irregular shape is the contribution of differential scattering. The differential scattering becomes increasingly more important for particles with dimensions greater than 1/20th the wavelength of light. This contribution was minimized by increasing the acceptance half-angle of detection. The present data indicate that bovine HMW alpha-crystallin has a different tertiary structure from LMW alpha-crystallin.

Absorption↗
PubMed1988

Oxalacetate decarboxylase and pyruvate carboxylase activities, and effect of sulfhydryl reagents in malic enzyme from Sulfolobus solfataricus.

Malic enzyme (S)-malate: NADP+ oxidoreductase (oxaloacetate-decarboxylating, EC 1.1.1.40) purified from the thermoacidophilic archaebacterium Sulfolobus solfataricus, strain MT-4, catalyzed the metal-dependent decarboxylation of oxaloacetate at optimum pH 7.6 at a rate comparable to the decarboxylation of L-malate. The oxaloacetate decarboxylase activity was stimulated about 50% by NADP but only in the presence of MgCl2, and was strongly inhibited by L-malate and NADPH which abolished the NADP activation. In the presence of MnCl2 and in the absence of NADP, the Michaelis constant and Vm for oxaloacetate were 1.7 mM and 2.3 mumol.min-1.mg-1, respectively. When MgCl2 replaced MnCl2, the kinetic parameters for oxaloacetate remained substantially unvaried, whereas the Km and Vm values for L-malate have been found to vary depending on the metal ion. The enzyme carried out the reverse reaction (malate synthesis) at about 70% of the forward reaction, at pH 7.2 and in the presence of relatively high concentrations of bicarbonate and pyruvate. Sulfhydryl residues (three cysteine residues per subunit) have been shown to be essential for the enzymatic activity of the Sulfolobus solfataricus malic enzyme. 5,5'-Dithiobis(2-nitrobenzoic acid), p-hydroxymercuribenzoate and N-ethylmaleimide caused the inactivation of the oxidative decarboxylase activity, but at different rates. The inactivation of the overall activity by p-hydroxymercuribenzoate was partially prevented by NADP singly or in combination with both L-malate and MnCl2, and strongly enhanced by the carboxylic acid substrates; NADP + malate + MnCl2 afforded total protection. The inactivation of the oxaloacetate decarboxylase activity by p-hydroxymercuribenzoate treatment was found to occur at a slower rate than that of the oxidative decarboxylase activity.

Archaea↗
PubMed1988

Evaluation of the dilator capacity of skin blood vessels of hypertensive patients by laser Doppler flowmetry.

Knowledge of regional circulation in the skin of hypertensive patients is largely incomplete. We examined the vasodilator capacity of skin blood vessels in the foot in 20 hypertensives and in 20 age- and sex-matched normal control subjects. Vasodilator capacity was assessed by measuring skin blood flow (laser doppler flowmetry) and cutaneous vascular resistance at rest and at the peak of the postocclusive reactive hyperemia response. Skin blood flow was higher in hypertensive patients than in controls at rest (69.4 +/- 23.6 vs. 44.2 +/- 17.5 mV; P less than 0.003), but did not differ significantly after reactive hyperemia (89.2 +/- 23.5 vs 88.2 +/- 25.4 mV; N.S.). Calculated cutaneous vascular resistance was higher in controls at rest (2.99 +/- 1.06 vs 2.22 +/- 0.81 a.u.; P less than 0.3), but lower after reactive hyperemia (1.43 +/- 0.44 vs 1.64 +/- 0.43 a.u.; N.S.). Laser Doppler flowmetry is a technique suitable for studying the alterations in cutaneous microcirculation induced by hypertension. These data are compatible with structural changes in the vascular wall of hypertensive patients.

Adult↗
PubMed1988

Solitary arterial trunk with pulmonary atresia and arteries with supply to the left lung from both an arterial duct and systemic-pulmonary collateral arteries.

We report a case of pulmonary atresia with ventricular septal defect and absent pulmonary trunk. The sources of pulmonary blood supply were the arterial duct and systemic pulmonary collateral arteries. The left lung received blood from both sources which is very rare. One of the systemic pulmonary collateral arteries arose from the right coronary artery in an unusual fashion.

Collateral Circulation↗
PubMed1988

Continuous computerized monitoring of hemodynamic parameters during acetate dialysis, bicarbonate dialysis, and acetate-free biofiltration.

The effects of continuous, computerized, non-invasive hemodynamic monitoring on the appearance of intradialytic symptoms, aided by preventive therapeutic maneuvers, were evaluated in 30 critically ill patients undergoing regular acetate dialysis. The hemodynamic behavior was assessed by a system that interfaces a personal computer with a blood pressure monitor and to a transthoracic electrical impedance-measuring instrument. Monitoring allowed us to reduce significantly the frequency of some important intradialytic symptoms such as nausea, vomiting, and hypotension. The same monitoring system was used acutely to characterize differing hemodynamic behaviors during acetate dialysis (AD), bicarbonate dialysis (BD), and acetate-free biofiltration (AFBF). AD showed a prevalent vasodilation effect with a compensatory increase in heart rate and higher cardiac output values, which were not sufficient to maintain blood pressure stability. BD and AFBF were characterized by a more efficient vasoconstrictor effect and good hemodynamic stability. AFBF, despite a 1 h reduction in session length compared to BD, did not present significant differences in hemodynamic response resulting from session shortness or other technical changes.

Acetates↗
PubMed1988

[Prognostic factors in surgery of ruptured aneurysms of the abdominal aorta].

From 1978 to 1986 83 patients underwent surgery for ruptured abdominal aortic aneurysm. The intraoperative and post-operative mortality rates was 34%. This multivariant analysis has been performed with intention of identifying the specific factors that affected the surgical outcome of ruptured abdominal aortic aneurysms. Increased intraoperative mortality rates were associated with heart disease, while postoperative mortality rates were associated with preoperative hypotension, BUN, levels higher than 40 mg/dl and other factors like duration of operation, blood less, blood transfusion and pre-operative hematocrit.

Aorta, Abdominal↗
PubMed1988

Prostatic tissue concentrations and serum levels of Myocamicin in human subjects.

The diffusion of Myocamicin in the prostatic tissue of patients undergoing prostatectomy after a single oral dose of 600 mg has been studied. The maximum concentration of antibiotic in the prostatic tissue and the serum peak are reached at the first hour with mean values respectively of 3.8 micrograms/g and 2.6 micrograms/ml. The concentrations of Myocamicin remain more elevated in the prostatic tissue compared with the serum levels, at the second, fourth and sixth hours. Myocamicin has shown itself to be an antibiotic with optimal capabilities of diffusion in the prostatic tissue, where it rapidly reaches good therapeutic concentrations.

Humans↗
PubMed1988

Empiric antimicrobial therapy for febrile granulocytopenic cancer patients: lessons from four EORTC trials.

The results of the four EORTC trials conducted over the past 15 years suggest: (1) early empiric therapy with broad spectrum antibiotics directed against gram-negative bacterial bacteremia (GNBB) is a reasonable approach in febrile granulocytopenic patients (GCP); (2) the level and dynamics of the granulocyte count are extremely important in determining the outcome of bacteremia; severely and/or persistently neutropenic patients are the true tests of antibiotic efficacy and they benefit from antimicrobial synergism; (3) mortality from GNBB in GCP is not related directly to a given empiric antimicrobial regimen which may 'buy time' and allow appropriate therapeutic alterations; (4) only microbiologically documented infections and especially bacteremias are useful to compare responses to antimicrobial regimens; (5) the response rate of GNBB is clearly influenced by the susceptibility of the causative pathogen to the beta-lactam component of the empiric regimen and emergence of resistance to some antibiotics (cephalothin, carbenicillin, ticarcillin, azlocillin) has rendered some combinations less effective. The combination of an anti-Pseudomonas beta-lactam plus an aminoglycoside is recommended as the 'standard' for empiric therapy in febrile GCP; (6) gram-positive pathogens have become a common cause of bacteremia in GCP and although the response rate to empiric regimens may be marginal, the associated mortality is low. A general conclusion from these trials is that studies of the management of infection in GCP should include sufficient numbers of eligible patients to allow for evaluation of bacteremic patients at highest risk of death. The need for large collaborative studies stems directly from these considerations.

Agranulocytosis↗