Biomedical subjects
Publications and source records attributed to B Grassi.
The identification of Gc (vitamin D binding protein) with the anionic polypeptide cochemotaxin has recently been reported. In this paper we investigate its dose dependent cochemotactic activity and report the inhibition of Gc enhanced chemotaxis by vitamin D3. These results further support the role of immunomodulating hormone played by vitamin D.
End tidal O2 and CO2 (PETCO2) pressures, expired volume, blood lactate concentration ([Lab]), and arterial blood O2 saturation [dry breath holds (BHs) only] were assessed in three elite breath-hold divers (ED) before and after deep dives and BH and in nine control subjects (C; BH only). After the dives (depth 40-70 m, duration 88-151 s), end-tidal O2 pressure decreased from approximately 140 Torr to a minimum of 30.6 Torr, PETCO2 increased from approximately 25 Torr to a maximum of 47.0 Torr, and expired volume (BTPS) ranged from 1.32 to 2.86 liters. Pulmonary O2 exchange was 455-1,006 ml. CO2 output approached zero. [Lab] increased from approximately 1.2 mM to at most 6.46 mM. Estimated power output during dives was 513-929 ml O2/min, i.e. approximately 20-30% of maximal O2 consumption. During BH, alveolar PO2 decreased from approximately 130 to less than 30 Torr in ED and from 125 to 45 Torr in C. PETCO2 increased from approximately 30 to approximately 50 Torr in both ED and C. Contrary to C, pulmonary O2 exchange in ED was less than resting O2 consumption, whereas CO2 output approached zero in both groups. [Lab] was unchanged. Arterial blood O2 saturation decreased more in ED than in C. ED are characterized by increased anaerobic metabolism likely due to the existence of a diving reflex.
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A portable ECG recorder was used during breath-hold dives at sea by 3 elite divers to 65 and 45 m. ECG was also recorded during nonimmersed maximal breath holds in the divers and 8 control subjects. Heart rate in the dives decreased rapidly to 20-24 beats.min(-1). During the surface experiments in the divers, bradycardia was much slower in onset, reaching 28-36 beats.min(-1) at the end of the breath holds. The divers showed a more consistent bradycardial response than the controls. The difference in temporal pattern of bradycardia, in the dives and in the breath holds by the divers, may have been due to face immersion in cold water, chest compression, and/or redistribution of blood into the chest with concomitant stimulation of cardiac and other mechanoreceptors. Arrhythmias, mostly supraventricular and ventricular premature complexes, were observed coincidently with the lowest heart rates, presumably reflecting a high vagal tone. In addition, cardiac distention at depth might have made the heart more prone to arrhythmias, while in the surface breath holds hypoxia might have accounted for a similar effect.
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The aim of this work was to evaluate the phytohaemagglutinin-induced aggregation of circulating neutrophils isolated from 25 patients affected by chronic myeloproliferative syndromes (polycythaemia vera, chronic myeloid leukaemia in chronic phase, and essential thrombocythaemia). The results showed a lesser aggregating capacity in chronic myeloid leukaemia (CML) and an opposite behaviour in polycythaemia vera and essential thrombocythaemia. Patients with polycythaemia vera whose neutrophils showed a greater aggregating capacity were shown to have had various vascular complications.
Hepatoprotective actions of metadoxina and ubiquinone have been studied in alcoholic rats by evaluating hepatic triglyceride accumulation and serum biochemical parameters of liver function. The two drug-treated groups displayed significantly lower triglyceride concentrations as compared to the ethanol-treated group. No significant differences were found among the two drug-treated and the control groups. Electron-microscopic abnormalities were found only in ethanol-treated rats. Serum biochemical parameters of liver function did not show any significant difference among all four groups. These results suggest a possible protective role of metadoxina and ubiquinone in ethanol-induced liver triglyceride accumulation.
It has been recently shown that 1,25(OH)2D3 induces differentiation and inhibits the proliferation of normal and leukemic cells in vitro. A review of the literature and the preliminary clinical applications of this vitamin in hematology are reported.
Serum levels of total cholesterol and triglycerides were studied in 202 patients affected by various hematological malignancies at the time of diagnosis. A hypocholesterolemia was found in 44% of patients affected by lymphoproliferative diseases and acute lymphoblastic leukemia, with an evident correlation with the clinical stage (5.7% of patients in nonadvanced stages, 67.8% in advanced stages). In acute and chronic myeloproliferative diseases, the overall incidence of hypocholesterolemia was 71%. In particular, a greater incidence of low cholesterol values was found in chronic myeloid leukemia and in idiopathic myelofibrosis than in polycythemia vera. No significant correlation was found in this group of diseases between the values of cholesterol and the main hematological parameters studied (WBC, number of circulating blasts, degree of splenomegaly, levels of hemoglobin, hematocrit). The incidence of significant alterations of triglycerides appeared negligible. It is thus possible to affirm that hypocholesterolemia constitutes an interesting biological aspect in hematological malignancies, and that total cholesterol could represent a parameter, even though secondary, in the follow-up of hematological neoplastic pathologies.
In human heart transplant recipients (HTR) an impairment of the cardiac function was expected to reduce peak oxygen consumption and the kinetics of the adjustment of respiratory gas exchange at the onset of rectangular work loads. In nine patients (males, 23-59 yr) 1 to 8 months after cardiac transplantation average peak VO2 (VO2p) was 1.1 L.min-1 +/- 0.3 (SD), i.e. 45% of that of the controls, the corresponding VCO2p value being 1.4 L.min-1 +/- 0.3 (SD). Mean VEp was 62.9 L.min-1 +/- 20.3 (SD), mean HRp was 136 beats.min-1 +/- 11 (SD), i.e. 45 beats.min-1 higher than preexercise values. Mean [Lab]p was 7.7 mM +/- 1.7 (SD), indicating that at the heaviest load the HTR were performing work at or above their maximum aerobic power. During the initial 60-90 sec of the transition from rest to graded rectangular exercise HR did not change from the resting value, increasing thereafter almost linearly with time. The half time (t1/2) of the VE on-response was 112 sec +/- 30 (SD) (controls values: 59 sec +/- 16), that of the VCO2 on- was 95 sec +/- 18 (SD) (58 sec +/- 11), and that of the VO2 on- was 78 sec +/- 24 (SD) (38 sec +/- 6). In spite of the slow kinetics of the VO2 on- response, no massive accumulation of lactate was found in the early phase of exercise. The limitation of the peak exercise in HTR appears to be imposed by a reduced maximal cardiac performance. The slow readjustment of the latter, as expected from the sluggish heart rate response, however, does not impair substantially the work load transients nor reduce the anaerobic threshold.
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A patient with copper deficiency and renal failure was suffering from pancytopenia. Marrow examination showed cytoplasmic and nuclear vacuolizations of the erythroid and myeloid series. These abnormalities disappeared after oral copper therapy. Possible mechanisms causing the pancytopenia are discussed. Copper supplementation is needed for patients receiving dietary changes.
Corticosteroids and cytostatic drugs possess a documented lesive action on upper digestive mucosa, making epigastric pain and/or pyrosis common complaints among patients on antitumor treatment. The selective antimuscarinic pirenzepine and the H2-receptor antagonist ranitidine were tested against the ulcerogenic action of antiblastic chemotherapy. Thirty-eight patients affected with malignant lymphoproliferative disorders were endoscopically examined and the endoscopic pictures were quantified by using an arbitrary score. According to a double-blind randomized sequence, 19 out of the 38 patients received pirenzepine 100 mg/die/p.o. and the other 19 received ranitidine 300 mg/die/p.o. along with antitumoral therapy for periods of 3-6 months. Seven patients died of hematologic complications before ending the treatment. In the 31 surviving patients (13 pirenzepine- and 18 ranitidine-treated) a second endoscopic examination was performed at the end of the treatment and the lesion score repeated. No significant difference was found between initial and final scores in both groups. The antisecretive action of the two drugs may account for their effectiveness, but other mechanisms such as cytoprotection cannot be ruled out.
The modifications in the concentration of circulating myoglobin have been studied by means of a radioimmunoassay in 15 cancer patients undergoing polychemotherapy including adriamycin. In 8 patients significant increases in myoglobin levels were found after injection of low doses of the drug (25-50 mg/m2). Moreover, a disturbance of the normal biorhythm of the protein was evident in 12 patients. Creatine kinase-MB was evaluated by means of a radioimmunoassay, but there was no relation between an increase in the isoenzyme and an increase in myoglobin. No ECG modifications were detected. These data indicate that the measurement of myoglobin may offer an indication of myocardial or skeletal muscle damage caused by adriamycin.
Both prednisone and cytostatic drugs have an ulcerogenic effect on digestive mucosa. The protective action of the antisecretory drugs pirenzepine and ranitidine are compared against gastroduodenal lesions induced by antiblastic therapy. Twenty patients affected with lymphoproliferative disorders were endoscopically examined: none of them suffered from gastric or duodenal peptic ulcers or erosions. Ten out of the 20 patients received pirenzepine 100 mg/die/p.o. and the other 10 received ranitidine 300 mg/die/p.o. The study was performed according to a double-blind, randomized sequence. The antisecretory medication was administered together with antitumoral therapy for periods of 3-6 months. Four patients died of haematological complications before the course of treatment was completed. A further endoscopic examination was performed at the end of treatment: no patient showed evidence of gastric or duodenal peptic ulcers or erosions. Among the pirenzepine-treated cases, 1 out of the 7 evaluable patients showed a histological worsening of a pre-existing gastritis, while a slight duodenitis was observed in 1 out of the 9 ranitidine-treated patients. The comparable effectiveness of the two drugs is probably related to their antisecretory action, but cytoprotective mechanisms cannot be excluded.
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The effects of lithium carbonate on leukocyte functions in a case of chronic benign neutropenia are presented. Lithium was able to induce leukocytosis and to bring about increases in chemotaxis, marrow granulocyte reserve test and phagocytosis. After lithium interruption, leukocyte functions returned to initial values. Some hypotheses are advanced to account for lithium action.