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Biomedical subjects

C Konen

Publications and source records attributed to C Konen.

10 recordsLinked to original sources
PubMed1986

Intrauterine contiguity influences regulatory activity in adult female and male mice.

Female mice located in utero between two female fetuses exhibited higher levels of locomotor activity in adulthood than did females located between two male fetuses. Male mice, which were less active than females, also were influenced by intrauterine contiguity. Males located in utero between two female fetuses were more active than males which resided between two male fetuses. These results indicate that intrauterine position influences behaviors involved in the maintenance of metabolic homeostasis.

Animals↗
PubMed1984

The role of progesterone in pregnancy-induced aggression in mice.

A series of six experiments was performed in order to explore the potential involvement of progesterone (P) in pregnancy-induced aggression (PIA) displayed by Rockland-Swiss mice toward adult male intruders. In Experiment 1, circulating levels of P and aggression were low on gestation Days 6 and 10 while both the behavior and the steroid reached peak levels by gestation Day 14. By gestation Day 18 (the day prior to parturition), serum P was at its lowest level yet aggressive behavior was still intense. Also, individual differences in the display of fighting behavior by pregnant females were not related to circulating P. Experiments 2 and 3 showed that supplemental P treatment to early pregnant female mice did not advance the onset of aggression. Experiment 4 showed that P treatment promoted the onset and elevated the incidence of aggression in virgin mice, but only in those females with intact ovaries. Experiment 5 showed that the aggressive behavior of P-stimulated virgin females was qualitatively and quantitatively different from that exhibited by pregnant mice in that the former exhibited fewer attacks and lunges than the latter. Finally, Experiment 6 showed that the removal of P from aggressive, P-stimulated virgins dramatically attenuated levels of the behavior. This contrasts sharply with the continued fighting behavior observed in late pregnant P-deficient mice. Thus, although P augments aggression in female mice it apparently is not a sufficient stimulus for producing pregnancy-like aggressive behavior.

Aggression↗
PubMed1983

Intermale aggression and infanticide in aged C57BL/6J male mice: behavioral deficits are not related to serum testosterone (T) levels and are not recovered by supplemental T.

Healthy aged adult (24-26 months of age) and young adult (2-4 months of age) c57BL/6J male mice were assessed for intermale aggression, pup-killing behavior (infanticide), and circulating levels of testosterone (T). When compared to young adult male mice, aged adult males were highly variable in the exhibition of both androgen-dependent behaviors. Significant numbers of aged males exhibited deficits in aggression and pup-killing while other animals were as behaviorally active as their young male counterparts. Assessment of serum T showed that aging did not produce a reduction in levels of the steroid and individual variability in androgen-dependent behavior of aged males was not related to plasma levels of the hormone. When aged non-aggressive and non-killer males were exposed to supplemental T by way of subcutaneously implanted silastic capsules, circulating levels of the steroid were elevated but T-dependent behavior was not recovered. These findings, in combination with those previously reported for copulatory behavior, indicate that the deficits observed in the androgen-dependent behavior of aged male mice cannot be attributed to a breakdown in the production of testicular androgens. While neural refractoriness to T may account in part for deficits in androgen-dependent behavior of aged males, the variability that is observed in the reproductive behaviors of aged male rodents ultimately may be related to other sources of variation such as the perinatal environment.

Aggression↗
PubMed1982

[Experiences with the 1st 1400 posterior chamber lens implantations after phacoemulsification].

Since May 1979 the authors have performed 3000 posterior chamber lens implantations; the purpose of this report is to present interim data on the first 1400 cases. The mean age of the patient was 69 years; lens power was determined biometrically, and the diopter range of the implant lenses was between 10 and 30 D. Postoperatively 93.7% of the patients had a visual acuity of 0.5 or better, 70% between 0.8 and 1.0. Serious complications, such as corneal edema, lens luxation and expulsive choroidal hemorrhage have not occurred so far; slight complications such as decentration of the lens, secondary, glaucoma and synechiae have seldom been observed and have reacted favorably to therapy.

Aged↗
PubMed1975

Bioavailability of m-octopamine in man related to its metabolism.

The diminished sympathomimetic pressor activity of monohydroxylated phenylalkylamines after oral administration has been attributed to incomplete enteric absorption. Therefore, urinary excretion of the unchanged drug and its metabolites has been compared after intravenous and oral administration of 3H-m-octopamine to eight patients. Identical amounts of 3H-activity (80% of the dose) were excreted after the two routes of dosing, so enteric absorption has been assumed to be complete. Significant differences were found in the fraction of free urinary m-octopamine, which amounted to 10.5% of the dose after infusion and 0.58% after oral administration. The only metabolic pathways for m-octopamine are deamination and conjugation. Following oral administration the percentage of conjugates was considerably higher than after intravenous infusion. This metabolic pattern appears typical of all phenylalkylamines with a hydroxyl group in the meta position. Ring hydroxylation to catecholamines was not observed. The enzymes mainly responsible for conjugation after oral administration are located in the gut wall. The resulting ""first pass effect'', i.e. metabolism prior to the access to the central compartment, can account for the diminished pharmacodynamic effect after dosing by this route.

Administration, Oral↗