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Biomedical subjects

D Jacob

Publications and source records attributed to D Jacob.

At least 73 records · Page 4Linked to original sources
PubMed1991

Laparoscopic appendectomy using a clip applier.

The diagnostic worth and therapeutic value of laparoscopic surgery are known for ovarian cysts and ectopic pregnancies. Diagnosis of appendicitis is difficult, and laparoscopy is useful in these cases. The present study was done to assess the feasibility, efficacy, and advantages of a new laparoscopic appendectomy technique. Between August 1, 1989, and July 31, 1990, patients exhibiting right pelvic pain associated with fever were divided into three groups according to the pre-operative diagnosis: appendicitis, pelvic inflammatory disease (PID), and diagnostic doubt between appendicitis and PID. An intra-peritoneal appendectomy was performed if the diagnosis was not PID. Via three suprasymphyseal trocars, the appendix was exposed and the mesoappendix was coagulated. The appendix stump was closed using a clip applier (Ethnor T1300). In all, 20 patients underwent laparoscopic appendectomies. The mean duration of the procedure was 36.5 min; in no case was laparotomy necessary. There were no post-operative complications, and digestive transit returned on the 2nd day post-surgery. Both patients and nurses appreciated the technique. The subjects experienced comfortable post-operative periods and gained aesthetic advantages. The operative procedure could be completed on each attempt. We conclude that this technique is sure, quick, and easily reproducible in young patients presenting with right pelvic pain associated with fever.

Appendectomy↗
PubMed1991

Mechanism of action of the urinary bladder carcinogen N-nitrosobutyl-3-carboxypropylamine.

The carcinogenic action of N-nitrosodibutylamine in the urinary bladder is related to omega-oxidation of a butyl chain. N-Nitrosobutyl-4-hydroxybutylamine and its proximate metabolite N-nitrosobutyl-3-carboxypropylamine (NBCPA) selectively induce urinary bladder tumours in different animal species. The mechanism by which NBCPA exert its carcinogenic action is not known. We found a small but significant dealkylation of NBCPA with microsomes from rat liver or pig urinary bladder, which could be inhibited by SKF 525A. NBCPA was not mutagenic to Salmonella typhimurium (with or without external metabolizing systems from rat liver or pig urinary bladder) and did not induce DNA strand breaks in tumour cell lines (with or without external activation) or primary cells (rat hepatocytes, pig urinary bladder epithelia). Significant induction of sister chromatid exchange and micronuclei, however, was observed in human tumour cells. N-Nitrosoureas that generate the same electrophiles as NBCPA after alpha- or via beta-oxidation (N-butyl-N-nitrosourea, N-3-carboxypropyl-N-nitrosourea and N-2-oxopropyl-N-nitrosourea) induced single-strand breaks in Namalva cells, the oxopropyl compound being more potent than the butyl or carboxypropyl compounds. Our data suggest that NBCPA is activated via alpha-oxidation in the urinary bladder, even though the activation rate in vitro is so low that a positive response is not detectable by classical short-term tests. Provided that beta-oxidation to a highly genotoxic agent proceeds at an adequate rate, it might also be a relevant activation pathway.

Animals↗
PubMed1989

Investigations on organ-specific metabolism and genotoxic effects of the urinary bladder carcinogen N-nitrosobutyl-3-carboxypropylamine (BCPN) and its analogs N-nitrosodibutylamine (NDBA) and N-nitrosobutyl-4-hydroxybutylamine (4-OH-NDBA).

N-Nitrosodibutylamine (NDBA) and its omega-oxidized metabolites N-nitrosobutyl-4-hydroxybutylamine (4-OH-NDBA) and N-nitrosobutyl-3-carboxypropylamine (BCPN) are potent urinary bladder carcinogens. To study putative organ specific activation of BCPN, its alpha-oxidation by liver and urinary bladder microsomal fractions was investigated in comparison to NDBA and 4-OH-NDBA. Additionally, induction of DNA single strand breaks (SSB) was monitored in hepatocytes and in a human lymphoblastoid cell line (Namalva) in the presence and absence of external metabolic activation, including N-nitroso-t-butyl-n-butylamine as a negative control. BCPN was alpha-hydroxylated and dealkylated at both alkyl chains in small rates (about 1 nmol x mg protein-1 x 60 min-1) by microsomes from rat liver and pig urinary bladder epithelium. NDBA and 4-OH-NDBA were dealkylated at similarly low rates by pig urinary bladder microsomes, in strong contrast to the high debutylation rates observed for rat liver microsomes. Correspondingly, SSB induction by NDBA and 4-OH-NDBA was observed in Namalva cells with NDBA and 4-OH-NDBA in the presence of PB-induced rat liver microsomes but not with urinary bladder microsomes or without external activation. BCPN did not induce DNA-damage in Namalva cells (with or without external activation) or in rat hepatocytes. Significant induction of sister chromatid exchanges (SCEs) and micronuclei, however, was observed in Namalva cells after incubation with NDBA and BCPN. Our data suggest activation of BCPN via alpha-oxidation in the urinary bladder, even though activation rate in-vitro is so low that a positive response is not detectable by several short-term tests.

Animals↗
PubMed1983

[3 years' observation of the clinical course of non-A, non-B hepatitis].

The three-year course of the cure after falling ill with a non-A/non-B hepatitis may be regarded as benign in 27 female patients. In several patients slight subjective complaints developed. Seven women even took the load of a new pregnancy. Transitions into a chronically aggressive hepatitis or cirrhosis were not observed.

Female↗
PubMed1976

Seasonal study of the adrenal gland of some Indian avian species.

Adrenal glands of eight Indian species of birds, namely Columba livia, Passer domesticus, Corvus splendens, Acridotheres tristis, Acridotheres ginginianus, Milvus migrans, Francolinus pondicerianus and Bubulcus ibis were examined during the sexually active and inactive phases of their annual reproductive cycles. Excepting A ginginianus and M. migrans, among members of either sex of the remaining six species the weight of the adrenal gland increases during the period of sexual activity. Histologically, the interrenal tissue of these birds could be divided into a peripheral subcapsular zone and a central zone. The cytochemical content of these two zones varies between sexual activity and inactivity. In sexually active birds of both sexes, interrenal cells of the central zone exhibit an increased concentration of alkaline phosphatase, glycogen, acid mucopolysaccharides and gross lipids, while in the subcapsular interrenal cells there is a prominent increase of ascorbic acid content. Cytochemical contents of chromaffin cells remain unchanged except acid phosphatase, which increases during the sexually active phase.

Acid Phosphatase↗
PubMed1975

Effect of sex steroids on the male reproductive organs of the monitor lizard Varanus monitor (Linn.).

Exogenous sex steroids were administered to adult males of the monitor lizard Varanus during the retrogressive and inactive phases of their annual reproductive cycle. Androgen treatment renews spermatogenetic activity and causes an increase in the number of Leydig cells of the testis during the retrogressive phase; during the inactive phase the testicular response to androgen is only slight. In either reproductive phase oestradiol treatment has an inhibitory action on the germ tubules. Progesterone has no effect on the testis in the inactive phase. The vasa deferentia are well developed during the retrogressive phase and thus the effect of androgens is not appreciable. However, during the inactive phase testosterone highly stimulates the deferent ducts. In the inactive phase oestrogen and progesterone also seem to stimulate slightly the deferent tubules; progesterone increases the interstitial tissue of the deferent ducts. Renal sexual segments hypertrophy and become secretory by androgen treatment in either phase of the reproductive cycle, whereas oestrogen and progesterone have no effect. The hemipenes are also stimulated by androgen treatment.

Animals↗