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Biomedical subjects

K Lee

Publications and source records attributed to K Lee.

At least 559 records · Page 31Linked to original sources
PubMed1995

Effects of cage density on fear-related behavioral response and activity of layers.

Two experiments were conducted to study the effects of cage density on fear-related behavioral response and activity of White Leghorn layers. In Experiment 1, 20-wk old pullets were placed into 30.5 x 50.8 cm cages at the rate of one, two, three, and four birds per cage for Treatments 1, 2, 3, and 4, respectively. In Experiment 2, birds were placed into cages (30.5 x 50.8 cm) at the rate of one, two, three, four, three, two, and three birds per cage for Treatments 1, 2, 3, 4, 5, 6, and 7, respectively, at 20 wk of age. At 28 wk of age, one bird was removed from each cage in Treatment 5, and one bird was added to each cage in Treatments 6 and 7. Fear-related behavioral response of the birds, as determined by the duration of induced tonic immobility (TI), and bird activity, as determined by the head movement (HM) count, were measured at 52 wk of age in Experiment 1, and at 29, 36, and 52 wk of age in Experiment 2. Increasing cage density had no effect on fear-related response of the birds in both experiments. Cage density effect on bird activity was not consistent. In Experiment 1, HM count was not affected by cage density, whereas in Experiment 2, pullets in the multiple-bird cage had a lower (P < or = .05) HM count (three-period average) than the birds housed individually. There was no correlation between the duration of induced TI and HM count in both experiments.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Effects of population density on layer performance.

Four experiments were conducted to study the effects of population density on layer performance. in each experiment, 20-wk--old White leghorn pullets were housed in 30.5 x 50.8 cm cages at the rate of one, two, three, and four birds per cage for Treatments 1, 2, 3, and 4, respectively. in Experiment 4, there were three additional treatments: for Treatments 5, 6, and 7, birds were placed into identical cages (30.5 x 50.8 cm) at the rate of three, two, and three birds per cage, respectively, at 20 wk of age. At 28 wk of age, one bird was removed from each cage in Treatment 5, and one bird was added to each cage in Treatments 6 and 7. In the first three experiments, all eggs that were collected for 2 consecutive d every 8 wk starting at 28 wk of age were used to measure egg traits. In Experiment 4, egg traits were determined once at 52 week of age. Birds at the highest population density had the lowest percentage hen-day egg production and had one of the poorest feed efficiencies. Egg production was negatively correlated (P < or = .01, Experiments 1, 2, 3; P < or = .05, Experiment 4) with population density. Feed required to produce a dozen eggs was positively correlated (P < or = .01, Experiments 1, 2; P < or = .05, Experiment 3) with population density in three out of the four experiments. The addition or removal of a cage mate to or from a multiple-bird cage in Experiment 4 did not (P > .05) affect egg production or feed efficiency. Final BW, mortality, and egg weight were not (P > .05) affected by population density. Only in one out of the four experiments was feed consumption (Experiment 1), eggshell thickness (Experiment 2), or albumen height (Experiment 3 lowered (P < or = .05) by having more than one bird per cage. This study showed that increasing population density decreased laying performance of the birds.

Animals↗
PubMed1995

[Radical prostatectomy in a patient with hemophilia B].

We describe our experience with radical prostatectomy in a patient with hemophilia B. whose factor IX activity was 7% and partial thromboplastin time was 55.9 sec. A total of 43,000 units of factor IX concentrate (PCC) was given perioperatively for 2 weeks. No abnormal hemorrhage was noted. An algorithm for perioperative management of hemophilia B patient is discussed.

Adenocarcinoma↗
PubMed1995

Comparison of antitumor activities of 2-chlorodeoxyadenosine and 9-beta-arabinosyl-2-fluoroadenine in chronic lymphocytic leukemia and marrow cells in vitro.

The in vitro antitumor activities of the nucleoside analogs, 2-chlorodeoxyadenosine (CdA) and 9-beta-arabinosyl-2-fluoroadenine monophosphate (Flu), and the alkylating agent, chlorambucil (CLB), were compared in leukemic cells from 28 patients with chronic lymphocytic leukemia (CLL). On a molar basis, the median sensitivities of the cells to these agents were CLB > CdA > Flu. CLL cells from 90% of the patients had similar relative orders of sensitivities to CdA and Flu, while cells from 10% of the patients showed differential sensitivities to these agents. There was no relationship between the sensitivities of the cells to the nucleoside analogs and sensitivity to CLB. CdA and CLB produced similar toxicities to human marrow progenitor cells in vitro, while Flu was less toxic to these cells. An 18 h exposure to CdA produced significantly greater cell kill of both CLL and marrow progenitor cells than an equivalent 2 h treatment; however, the difference in cytotoxicity was greater for the tumor cells resulting in a higher therapeutic index with the 18 h treatment. The intracellular accumulation of drug varied 5-fold for CdA, with the major metabolite being CdAMP, and 15-fold for Flu, with the major metabolite being F-ara-ATP. However, the accumulation of CdA, Flu or their metabolites did not predict for drug sensitivity. These studies suggest that CdA and Flu cross-resistance cannot be assumed in all CLL patients. The therapeutic effectiveness of CdA may be enhanced by use of a prolonged, low-dose drug regimen.

Antineoplastic Agents↗
PubMed1995

Metastatic pleural cancer in radionuclide angiocardiography. A pulmonary time-activity curve mimicking left-to-right cardiac shunt.

A 55-year-old man, with a history of nephrectomy for renal cell carcinoma, was evaluated using radionuclide angiocardiography to exclude cardiac shunts as the cause of vascular bruits heard at auscultation. A pulmonary time-activity curve derived from the right lung showed a pattern typical of a large left-to-right shunt, whereas that from the left lung was normal. Increased systemic arterial flow to the lateral right chest was noted in early dynamic images. Subsequent studies revealed that this flow and the abnormal time-activity curve of the right lung were due to systemic arterial supply to metastatic pleural cancer, originating from the kidney. The authors conclude that special caution should be undertaken in the interpretation of the radionuclide angiocardiography for determining left-to-right cardiac shunts, especially in those showing a asymmetric pulmonary time-activity curve.

Carcinoma, Renal Cell↗
PubMed1994

Biochemical changes, early brain growth suppression and impaired detour learning in nicotine-treated chicks.

Fetal growth suppression associated with chronic maternal intake of cigarette smoke is frequently observed in humans and studies using animal models suggest that in utero nicotine exposure is an important component of this growth suppression. The developing fetal central nervous system (CNS) is sensitive to the growth inhibitory effect of nicotine and morphological as well as functional CNS deficits may result from fetal nicotine exposure. The studies presented here show that nicotine exposure during early embryonic development ultimately inhibits the ability of 7-11 day old chicks to learn a detour task. The brain growth suppression caused by nicotine is paralleled by a failure of the early embryo brain to express the normal developmental increase in ornithine decarboxylase (ODC) activity. This biochemical change may be germane to the mechanism of nicotine-induced growth inhibition and/or nicotine-induced behavioral changes because the appropriate expression of ODC activity is essential to normal growth and differentiation in the fetal CNS. In the chick embryo, nicotine exposure alters several important signaling pathways that regulate ODC expression. For example, nicotine exposure lowers embryonic brain glucose levels and causes significant decreases in whole brain cyclic adenosine 3',5'-monophosphate (cyclic AMP) levels and in cyclic AMP binding proteins (protein kinase-A regulatory activity). Also, in cultured chick cells, nicotine inhibits the ability of a potent mitogen (insulin) to induce ODC activity, but, paradoxically, in ovo nicotine exposure increased insulin binding and stimulated insulin receptor autophosphorylation in brain membranes.

Animals↗
PubMed1994

The Doa locus encodes a member of a new protein kinase family and is essential for eye and embryonic development in Drosophila melanogaster.

Mutations at the Darkener of apricot (Doa) locus of Drosophila cause roughened eyes and increase transcript accumulation from the retrotransposon copia up to fourfold. Cloning of the gene and sequencing of cDNAs reveals that it encodes a putative serine/threonine protein kinase. Sequence data base searches identify it is a member of a novel highly conserved protein kinase family, with homologs in humans, mice, and Saccharomyces cerevisiae, not related to each other previously. Family members are characterized by a peptide motif reading EHLAMMERILG at kinase subdomain X, which is virtually 100% identical in all homologs. We therefore refer to this new family as the LAMMER protein kinases. As predicted from its primary sequence, Doa protein possess intrinsic protein kinase activity when expressed in bacteria, as assayed via autophosphorylation. The gene is expressed throughout development, and both stage and tissue-specific RNAs are found. Its function is essential, because maternally deposited or zygotically transcribed mRNA is required for development to larval stages, and defects in segmentation and development of the nervous system are observed in embryos derived from heteroallelic mothers. Doa function is also critical to Drosophila eye development, because the organization and development of pigment cells, bristles, and photoreceptors are affected in various mutant classes. In the most extreme cases that survive to adulthood, retinal photoreceptors degenerate prior to eclosion. These results demonstrate that the kinase encoded by Doa is required at multiple stages of development, for both differentiation and maintenance of specific cell types.

Amino Acid Sequence↗