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Biomedical subjects

M Colombo

Publications and source records attributed to M Colombo.

At least 289 records · Page 16Linked to original sources
PubMed1982

Geographic differences in HBV related, autoimmune, and cryptogenic chronic active hepatitis.

To clarify the importance of ethnic and geographic factors in chronic active hepatitis (CAH), HBV markers and autoantibodies (AMA, ANA, SMA), have been compared in 158 patients with biopsy-proven CAH from New York City and in 92 patients with CAH from Milan. HBsAg-positive CAH was more frequently observed in Milan (49%) than in New York City (27%). However, among HBsAg-positive patients, HBcAg, HBeAg, and epidemiologic risk factors for acquisition of HBV infection were more frequently found in New York than in Italy. The prevalence of HBsAg-negative, anti-HBc-positive CAH and cryptogenic CAH was similar in the two cities, while autoimmune CAH was more frequently observed in New York (20%) than in Milan (2%). In particular, the prevalence of autoimmune hepatitis was higher among Jewish patients than among patients of Anglo-Saxon or Latin ethnic background in New York. Thus, environmental and/or ethnic factors may influence the prevalence of the four major types of CAH.

Antibodies↗
PubMed1982

Nonprogressive course of non-A, non-B chronic hepatitis in multitransfused hemophiliacs.

Eleven hemophiliacs with chronic liver disease were studied prospectively for 6 yr, with liver function tests and liver biopsies carried out at intervals of 3 yr. The second series of biopsies, compared with the first series, showed continuation of chronic persistent hepatitis in four patients, change to chronic lobular hepatitis in two, and spontaneous improvement of the disease in the four cases who had had chronic active hepatitis characterized by moderate piecemeal necrosis. One patient with active cirrhosis died of liver failure during the follow-up period. Study of the serum and intrahepatic markers for hepatitis B and delta viruses suggests that chronic liver disease is nonprogressive in hemophiliacs who have no intrahepatic viral marker.

Adolescent↗
PubMed1982

Blood T and B cells in patients with acute viral hepatitis A, B and non-A non-B.

We studied the blood distribution of T and B cells in relation to the etiology and the course of the hepatitis process, in 61 consecutive patients with acute viral hepatitis (AVH). Patients with acute viral hepatitis B showed a significant increase in total T, active T and SmIg cells, lasting the first two weeks of disease. These alterations disappeared in patients with resolving hepatitis. SmIg cells remained persistently elevated in the blood of three patients, who developed chronic hepatitis B. In patients with other types of viral hepatitis, lymphocytes were unaltered, with the exception of a transitory increase in SmIg cells, during the convalescence phase of hepatitis A. The finding that lymphocytes were activated exclusively in patients with acute hepatitis B, but not in those with other types of hepatitis, suggests that the mechanisms of liver injury in hepatitis B may differ from those involved in the pathogenesis of hepatitis A and nAnB.

Adolescent↗
PubMed1980

Expression of alien minor histocompatibility antigens distinct from tumor-specific transplantation antigen on a murine fibrosarcoma.

The fibrosarcoma ST2, induced by 3-methylcholanthrene in BALB/c (H-2d) mice, also expressed alien histocompatibility antigens of the C3Hf and B10 background not encoded by the MHC. To examine the relationship between these alien, minor antigens and the tumor-specific transplantation antigen (TSTA) of the tumor, in vivo immunogenicity test were performed in BALB/c mice and in hybrids between BALB/c and C3Hf (H-2k), C3H.OH (H-2o2), C3H.SW (H-2b), BALB.K (H-2k), B10.BR (H-2k), and B10.D2 (H-2d) mice. A significant loss of TSTA immunogenicity was found in (BALB/c x C3Hf) and in (BALB/c x C3H.OH)F1 animals and, to a lesser extent, in (BALB/c x C3H.SW)F1 mice as compared to the immunogenicity of the tumor in BALB/c mice. Immunogenicity tests with ST2 in BALB/c x (BALB/c x C3Hf) or in BALB/c x (BALB/c x B10.D2) backcross mice, respectively, revealed that half of the BALB/c x (BALB/c x C3Hf) and 97% of the BALB/c x (BALB/c x B10.D2) animals were able to mount an immune response to ST2. To see whether the loss of TSTA immunogenicity in (BALB/c x C3Hf) was due to common determinants shared between TSTA and alien non-H-2 C3Hf antigens or to a genetically linked low responsiveness to TSTA introduced by C3Hf and C3H.OH strains, BALB/c mice were immunized with normal tissues of some BALB/c x (BALB/c x C3Hf) backcross, anti-ST2 resistant mice. Normal tissues of anti-ST2 resistant, dd and dk typed backcrosses were able to immunize BALB/c mice against a challenge of an otherwise lethal dose of ST2 cells. Some but not all BALB/c x (BALB/c x B10.D2) anti-ST2 resistant donors had tissues able to immunize BALB/c hosts aginst the ST2 growth. Since resistance to tumor growth and expression of minor "alien" antigens shared with the tumor segregate independently, we concluded that alien, minor C3Hf and B10 antigens of the BALB/c sarcoma ST2 are distinct from the TSTA of this tumor.

Animals↗
PubMed1979

Effects of chlordiazepoxide on maze performance of rats subjected to undernutrition in early life.

The purpose of this research was to study the isolated effects of and interactions between undernutrition and emotional reactivity upon maze performance in rats. This work compares the effects of chlordiazepoxide on learning performance in two groups of adult rats: one undernourished early in life and then rehabilitated, and the other normally nourished. Chlordiazepoxide was used at 5 mg/kg body weight administered i.p. 30 min before each test. The response was evaluated in a Hebb-Williams maze. Water was used as reinforcement. Chlordiazepoxide improved performance in the early undernourished group 197 +/- 55.9 errors to 149 +/- 33.6 (mean +/- SD). Chlordiazepoxide impaired performance of the normal group from 107 +/- 22.7 errors to 197 +/- 42.2 errors. Analysis of variance gave an F = 6.64, which is significant (P less than 0.01). This supports the hypothesis that the high emotional level of previously undernourished subjects acts negatively upon problem-solving performance.

Animals↗
PubMed1979

Effects of anticalcifying and antifibrobrotic drugs on pre-established atherosclerosis in the rabbit.

The effects of the anticalcifying drug, ethane-hydroxydiphosphonate (EHDP) and the inhibitors of collagen biosynthesis, colchicine, penicillamine and azetidine were studied in the rabbit with pre-established atherosclerosis. The drugs were administered with a cholesterol-free diet (regression diet) for 8 weeks following the induction of atherosclerosis by feeding a hypercholesterolemic diet containing 2% cholesterol and 8% peanut oil for 8 weeks. The extent and severity of aortic atherosclerosis, as revealed by the morphological and biochemical findings, increased significantly during the regression period. In rabbits treated with EHDP (5 mg/kg/day) the aorta had fewer gross lesions and contained significantly less cholesterol, collagen and elastin than did the aorta of the rabbits fed the regression diet alone. These changes were associated with a significant reduction in aortic calcium caused by EHDP. The aortic content of cholesterol, collagen and elastin in the EHDP-treated rabbits, although less than that of the rabbits fed the regression diet alone, was about the same as that of the rabbits fed a high cholesterol diet for 8 weeks. Both colchicine (0.2 mg/kg/day) and penicillamine (100 mg/kg/day) had a selective action on the induced plaques in that they suppressed the fibrous proliferation in the lesions without preventing lipid and calcium accumulation in the lesions. Neither colchicine nor penicillamine reduced the extent of aortic atherosclerosis as determined by gross examination of the vessel. Azetidine had no significant effect on the pre-established atherosclerotic lesions. The lipid, fibrous protein and calcium content of the aorta of the azetidine-treated animals was not significantly different from that of the untreated animals. The biochemical findings in the aorta were consistent with the microscopic changes.

Animals↗
PubMed1979

Effect of indoprofen on prostaglandin and thromboxane A2 synthesis in the guinea pig lung.

Indoprofen has been studied in vitro as a possible selective inhibitor of thromboxane-synthetase in guinea pig lungs perfused with arachidonic acid. Indoprofen does not show selectivity of action since KB values for prostaglandin and TXA2 synthesis are not significantly different. Indoprofen might therefore act at the cyclooxygenase level as has already been demonstrated for indomethacin.

Animals↗
PubMed1979

Long-term effects of early undernutrition and environmental stimulation on learning performance of adult rats.

Early undernutrition was achieved in rats by increasing litter size; the undernourished groups were reared from birth to 21 days in litters of 18 pups per dam and the control groups in litters of six pups per dam. Each of these groups was divided at weaning into two sub-groups: previously undernourished, stimulated (PUS+) and non-stimulated (PUS-); and control, stimulated (CS+) and non-stimulated (CS-). From weaning, all animals were fed ad libitum. Environmental manipulation began at weaning and lasted 11 weeks. "Stimulated" rats were maintained in colonies of three per cage, were handled for 5 minutes each day and allowed to explore a "stimulation chamber" for 30 minutes. All groups were tested in a Hebb-Williams maze at 100 approximately 10 days of age. The nutritional treatment did not impair Hebb-Williams performance, and environmental stimulation improved the learning performance both in control and previously undernourished groups. Neither nutritional nor stimulation treatment affected intraproblem learning. Total DNA and cholesterol were reduced in forebrain and cerebellum in undernourished rats. Brain stem was the region of the CNS least affected by early undernutrition. Environmental manipulation did not modify neurochemical parameters.

Animals↗
PubMed1978

Tartrazine and prostaglandin-system.

Tartrazine, a dye largely employed for colouring foods, drinks, drugs and cosmetics, induces in some aspirin-sensitive subjects a bronchoconstriction similar to that caused by aspirin and other nonsteroidal anti-inflammatory drugs. The interference of tartrazine on prostaglandin system of guinea pig lungs perfused with arachidonic acid has been studied. This compound is able to inhibit in the same manner the formation both of prostaglandins and of thromboxane A2 acting at the cyclooxygenase level as has already been demonstrated for aspirin and indomethacin. Preliminary experiments on aspirin asthmatic patients treated or not with tartrazine are discussed.

Animals↗
PubMed1978

A clinicopathological study of liver disease in haemophiliacs.

Chronic liver disease is not often reported in patients with haemophilia. Although a high incidence of abnormal liver function tests has been reported, the clinical significance of these findings and their relation to chronic liver disease cannot be established without a liver biopsy. The results of this procedure, carried out in 11 patients with severe haemophilia A and B, in whom SGOT had been persistently raised for three years, are reported. Five patients had chronic active hepatitis, four had chronic persistent hepatitis, one had cirrhosis, and one alcoholic hepatitis. No haemorrhagic complication followed the biopsy procedure, which was carried out in patients given prophylactic clotting factor concentrates. These results suggest that duration of abnormal liver function tests is likely to represent liver disease in haemophiliacs, and that biopsy should be considered to establish the diagnosis and plan a suitable therapeutic programme.

Adolescent↗