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Biomedical subjects

M Castagneto

Publications and source records attributed to M Castagneto.

At least 163 records · Page 9Linked to original sources

Quantification of the determinants of arterial hypoxemia in critically ill patients.

A quantification of the determinants of arterial hypoxemia was performed in 376 cardiorespiratory measurements obtained from 180 critically ill patients. Statistical analysis showed that pulmonary venous admixture (Qsp/Qt) could explain only 48% of the PaO2 variability in the sample of measurements taken (r2 = 0.48), while the effect of central venous O2 tension (PVO2) brought the total explained PaO2 variability up to 82% (total r2 = 0.82). These findings imply that pulmonary function is not the only determinant of PaO2; the PVO2-mediated effect of other cardiovascular and metabolic determinants must be recognized in the clinical setting.

Cardiac Output↗

Cardiorespiratory and metabolic adequacy and their relation to survival in sepsis.

Cardiorespiratory and metabolic data were collected in 36 septic patients and 80 patients critically ill after nonseptic general surgery or trauma. Septic patients, particularly nonsurviving septics, showed early and sustained increases in metabolic rate, oxygen consumption, cardiac work, and minute ventilatory volume. They had lower levels of respiratory quotient and total peripheral resistance than nonseptic patients. High cardiac work was related to increasing oxygen transport. Both increases in metabolic utilization with high CO2 production, and abnormal increases in VD/VT appeared responsible for the higher minute ventilatory volumes. Respiratory quotient was negatively related to metabolic rate; this relation was modulated by the rate of caloric intake and, in nonseptic patients, was also influenced by the hemodynamic state. These data suggest that poor prognosis in sepsis is characterized by an early sustained stress response with more severe abnormalities in cardiovascular, metabolic, and respiratory function than is seen in the nonseptic stress response. The need for early support of physiologic functions and early and aggressive nutritional intervention is emphasized.

Carbon Dioxide↗

Ogilvie's syndrome (acute colonic pseudo-obstruction): review of the literature (October 1948 to March 1980) and report of four additional cases.

Four additional cases of Ogilvie's syndrome (acute colonic pseudo-obstruction), representing the first cases described in Italy, are reported. The medical literature concerning the subject is also thoroughly reviewed. Ogilvie's syndrome is an acute massive dilatation of the large bowel without organic obstruction of the distal colon. Three hundred and fifty-one cases have been described in the literature to date. Eighty-eight per cent of the cases were associated with various extracolonic affections (metabolic and organ dysfunctions, postoperative and posttraumatic states, etc.). Twelve per cent of cases were not associated with known disorders and were defined as idiopathic. The pathophysiology of the syndrome is still unknown. Ogilvie, who first described the syndrome in 1948, suggested an imbalance between the sympathetic and parasympathetic innervation of the colon: this neurogenic hypothesis has been shared by other authors, although explanations may differ slightly. The clinical and radiologic picture closely resembles mechanical obstruction of the large bowel. The most marked dilatation usually takes place in the right colon and cecum: if the distended cecum reaches a diameter larger than 9 to 12 cm, perforation is likely to occur; if perforation occurs, the mortality rate increases from 25 to 31 per cent to about 43 to 46 per cent. If conservative management fails to control the dilatation and cecal rupture is impending or suspected emergency surgery is indicated, the surgical procedure of choice is dictated by the general conditions of the patient as well as by the intestinal findings: operation may consist of cecostomy, colostomy, or right hemicolectomy or simply emptying the bowel.

Adult↗

Lipid composition in jaundiced rat liver by radio-thin-layer chromatography and photodensitometry.

In vitro hepatic synthesis of lipids starting from (1-14C)acetate was investigated for 14 days in rats with biliary obstruction by ligation of the common bile duct using radio-thin-layer chromatography (radio-TLC). This study was correlated with a quantitative assay of the various hepatic lipids using TLC correlated with photodensitometry. Hepatic total lipid synthesis increased progressively with time. With concern to the single fractions, the major modifications were verified on the 3rd day with a decreased incorporation of the labelled acetate into the triglycerides. On the other hand, using photodensitometry, they demonstrated a percentage increase. These variations can be justified by the presence of a feedback mechanism. The syntheses of cholesterol and the other fractions were maximum during this period. Histologic examination revealed, especially on the 3rd day, a neoformation of biliary ductules and on the 14th day, a regression of these histological changes.

Acetates↗

Imbalances in peripheral blood T-cell subpopulations in renal transplant patients.

The distribution of T-lymphocyte subpopulations bearing receptors for the Fc portion of IgG (TG) or IgM (TM) was monitored in 22 renal allograft recipients treated with immunosuppressive therapy and in 10 uraemic patients on haemodialysis. No significant difference in the distribution of T cells and T-cell subsets was found between normal controls and haemodialysed patients. In transplanted patients, however, a significant reduction of the total T-cell percentage (P less than 0.005), of TM subset percentage (P less than 0.025) and absolute number (P less than 0.005) and of TG absolute number (P less than 0.05) was observed. Considering patients with allografts functioning for more than 1 year only, the reduction in TM cells in terms of percentage (P less than 0.0005) and absolute number (P less than 0.025) was significant, while TG subset levels did not change significantly. In patients transplanted less than 1 year previous to our study, total T cells and T-cell subsets were reduced significantly only as absolute numbers. During the 1st year we observed several increments of TM values towards normal levels, especially in the first 2 months after transplantation. During this period, TM subset levels sharply increased at acute rejection crisis and returned to previous values with rejection reversal. Our results suggest that the TM subset plays a prominent role in the mechanisms involved in the immunological response to allografts, and therefore repeated TM cell monitoring could be useful in the follow-up of renal transplant patients.

Graft Rejection↗

[Transplantation of the isolated pancreas in rats. Technical aspects].

An original microsurgical technique of pancreatic transplantation in the rat using the intact organ without duodenum is presented. Exocrine secretion was blocked by injection of an acrylate glue in the ductal system. This model seems to be simple and suitable to transplantation and metabolic research.

Animals↗

[Homotransplant of the isolated pancreas in the rat, with suppression of exocrine secretion. Results and considerations].

Twenty isolated pancreas allotransplantations were performed in "inbred" diabetic rats, after suppression of the exocrine secretion by injecting an acrylate glue into the ductal system. Metabolic investigations have demonstrated that the transplanted organ is able to restore the glycidic balance, whole histologic studies have shown that the acrylate glue produces pancreatic exocrine athrophy, without damaging Langerhans islets.

Alloxan↗