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Biomedical subjects

M Giralt

Publications and source records attributed to M Giralt.

At least 145 records · Page 8Linked to original sources

Differences between pregnant and nulliparous rats in basal and stress levels of metallothionein.

The present experiment was designed to examine the influence of pregnancy on basal and stress levels of serum and liver metallothionein (MT). Eighteen-day pregnant rats showed higher serum MT levels and lower liver MT levels than nulliparous rats, suggesting that a great MT mobilization from the liver into the serum was present in the former rats. Serum MT levels were not changed by either restraint or starvation. It is unlikely that the lower liver MT levels showed by pregnant rats were due to competition by progesterone for glucocorticoid receptors, as previously suggested, since the corticosterone/progesterone ratio was unchanged in pregnant rats. Liver MT response to food and water deprivation with or without restraint was somewhat different in nulliparous and pregnant rats. Thus, food and water deprivation for 24 h caused higher liver MT induction in pregnant than in nulliparous rats. When food and water deprivation was accompanied by restraint stress a further increase in liver MT was observed in nulliparous but not in pregnant rats. This suggests that food and water deprivation may be a more severe stress in pregnant rats because of the additional demands of the growing fetuses. Fetal liver MT was increased by restraint stress but not by food and water deprivation. The role of Zn influx into the liver is discussed.

Animals↗

Long-lasting effects of chronic chlorimipramine treatment of rats on exploratory activity on a hole-board, and on immobility in the forced swimming test.

The study concerned the effects of acute and chronic clomipramine administration to male rats on exploratory activity in a novel environment (hole-board) and on immobility in the forced swimming test. Acute clomipramine administration did not alter either exploratory activity on a hole-board as measured 3 or 20 h after drug administration, or immobility in the forced swimming test as measured 20 h after drug administration. Approximately 20 h after the last injection of clomipramine, the rats chronically treated with the drug showed reduced exploratory activity on the hole-board. In contrast, chronic clomipramine treatment significantly increased the activity in the forced swimming test. The effects of the drug on exploratory and forced swimming activities persisted for 14 days after the cessation of clomipramine administration. These data indicate that chronic clomipramine administration exerted profound and long-lasting effects on central nervous system function. The long-lasting action of the drug on behaviour in the forced swimming test might explain the long-term beneficial effect of antidepressant drugs in counteracting behavioral depression.

Animals↗

Nonsecretory multiple myeloma.

Among 186 patients with multiple myeloma (MM), five women were diagnosed as having MM without M-component in serum and or urine at the diagnosis and along the evolution. Bone marrow plasmacytosis at greater than 30% was found in all patients and bone x-rays showed lytic lesions in all but one case, osteoporosis in all, and pathologic fractures in two. Serum electrophoresis showed a striking hypogammaglobulinemia in all, and polyclonal immunoglobulin levels were markedly reduced. The immunofluorescence of plasma cells in bone marrow was positive for monoclonal light chain polypeptides in four patients, and the ultrastructure showed mature plasmocytes with a wide rough endoplasmic reticulum (RER) and an intact Golgi apparatus. In three patients, therapy with melphalan plus prednisone was started. The remaining two were treated with an M-2 protocol. Death was an early event in two patients; the response was good in the remaining patients, without differences regarding secretory MM. Despite some reports stressing an unfavourable prognosis in MM without M-component, in our series it is roughly the same as in MM with secretion.

Agammaglobulinemia↗

Previous chronic ACTH administration does not protect against the effects of acute or chronic stress in male rats.

The effect of previous chronic ACTH administration on the physiological response to acute and chronic immobilization stress was studied in adult male rats. Chronic ACTH administration slightly reduced food intake and drastically inhibited body weight gain. Serum corticosterone levels were similar in saline- and ACTH-treated rats twenty hours after the last administration. However, the corticosterone response to 1 hr immobilization was greatly reduced by previous ACTH administration. When the exposure to the stressor was prolonged up to 18 hours, the corticosterone response was similar in saline, and ACTH-treated rats. While body weight loss caused by starvation and acute stress was lower in ACTH-treated rats, stomach ulceration was greater in the latter animals. Although ACTH-treated rats showed higher body weight gain than saline-treated animals during chronic immobilization, this was probably due to catch-up growth as food intake inhibition caused by the stressor was similar in the two groups. Pituitary-adrenal adaptation to the repeated stressor was the same in saline- and ACTH-treated rats. Therefore, the effects of previous ACTH treated on the physiological response to either acute or chronic stress appear to be mixed, depending on the variable studied.

Adrenal Glands↗

Sex and restraint stress differences in rat metallothionein and Zn levels.

Sex differences in serum and liver metallothionein (MT) levels were studied in adult male and female rats. Whereas it was found that female rats had higher hepatic MT levels than male rats in basal, unstressed conditions, no significant differences were found in serum MT levels. Restraint stress increased both serum and liver MT in both sexes. The increase in serum MT was greater in male than in female rats, whereas no significant differences between sexes were found in liver MT content after restraint stress. It is suggested that MT regulation might be sex-dependent and that MT might play some extrahepatic function during stress.

Analysis of Variance↗

Impaired basal and noradrenaline-induced iodothyronine 5'-deiodinase activity in brown adipose tissue from pregnant and lactating rats.

Basal iodothyronine 5'-deiodinase activity is lowered in brown fat from 20-day pregnant, 5 and 15-day lactating rats when compared with virgin controls. Acute noradrenaline treatment caused a seven fold increase in 5'-deiodinase activity in brown fat from virgin control rats. Late pregnant and lactating rats showed a reduction in noradrenaline-induced 5'-deiodinase activity in brown adipose tissue and the maximum impairment was observed in 15-day lactating rats. Lowered 5'-deiodinase activity in brown fat during late pregnancy and lactation correlates with the known reduction in the thermogenic activity of the tissue during these situations and agrees with the proposal that the rate of 3,5,3'-triiodothyronine generated in situ because of thyroxine 5'-deiodination could be an essential event related to thermogenesis in brown fat. Even though the relationship between 3,5,3'-triiodothyronine generation in the tissue and the specific thermogenic mechanisms of brown fat is unknown, present results indicate a close link between the thermogenic and 5'-deiodinase activities in physiological situations when brown adipose tissue needs to adapt to a low activity, such as that of the breeding cycle.

Adipose Tissue, Brown↗

Acute nonlymphocytic leukemia (M7 subtype) with erythrocytic internalization.

A case of acute nonlymphocytic leukemia of megakaryocytic lineage or M7 with a conspicuous phenomenon of erythrocytic internalization present in nearly 3% of the leukemic megakaryocytic precursors (LMP) is reported. The phagocytosis was detected at light microscopy and ultrastructural levels. The erythrocyte might have reached the interior of the LMP through cytoplasmic vacuoles that are connected with the extracellular space and that can be considered rudimentary equivalents of the demarcation membrane system (DMS). Erythrocytic internalization is not a specific feature of the mononuclear phagocytic system and can be misleading in the classification of undifferentiated blast cells.

Bone Marrow↗

Fanconi's anemia. Clinical study of six cases.

Six cases of constitutional aplastic anemia (Fanconi's anemia), including four boys and two girls who were between 6 and 10 years of age, are presented. Congenital abnormalities were observed in all the patients, especially skin pigmentations, renal anomalies, and growth retardation. The initial symptoms were insidious, mainly related to the anemia. All patients were anemic and thrombocytopenic, but only three were leukopenic. Five cases showed increased levels of fetal hemoglobin, which was marked in two. Bone marrow obtained by aspiration and/or biopsy was hypocellular in all cases. Chromosomal studies showed breaks, ring- or cross-chromosomes, chromosome exchanges, and endoreduplications. Five cases were treated with androgens and a good response was obtained in all of them. Four patients died, and the remaining two are alive and well. The clinical and biological features of these patients are in accordance with those of previous reports. The importance of the androgen therapy is stressed; androgen dependence was observed in all cases.

Androgens↗

Treatment of chronic lymphocytic leukemia in advanced stages. A randomized trial comparing chlorambucil plus prednisone versus cyclophosphamide, vincristine, and prednisone.

Ninety-six patients with advanced chronic lymphocytic leukemia (CLL) (Stage C; anemia and/or thrombocytopenia of nonimmune origin) were randomized to receive either chlorambucil (CLR) (0.4 mg/kg orally, day 6) plus prednisone (PDN) (60 mg/m2 orally, days 1-5) every 2 weeks or cyclophosphamide (600 mg/m2 intravenously, day 6), vincristine (1 mg/m2 intravenously, day 6) and prednisone (60 mg/m2 orally, days 1-5) (COP) each month for 5 months. Complete remission (CR) was defined as the total disappearance of signs and symptoms related to the disease. Partial remission (PR) was considered to be achieved when, after treatment, the clinical stage changed to a less advanced one. Thirty (59%) responses (8% CR) with CLR plus PDN and 14 (31%, 2% CR) with COP were observed (P less than 0.01). The survival was not significantly different for the two groups. Patients previously treated had a lower number of responses (11/35, 31%) than those with no previous treatment (33/61, 54%) (P less than 0.05). Patients who attained a CR or a good PR had longer survivals (median not reached) than those with a poor PR (median, 25.2 months) or those who did not respond to treatment (median, 11.5 months) (P less than 0.005).

Aged↗