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Biomedical subjects

L S Keller

Publications and source records attributed to L S Keller.

10 recordsLinked to original sources
PubMed1997

Superovulation of New Zealand white rabbits by continuous infusion of follicle-stimulating hormone, using a micro-osmotic pump.

A successful method for superovulation of rabbits, which is more time effective than current protocols, has been established and consistently yields large numbers of fertilized ova. Subcutaneous microosmotic pumps were used to administer follicle-stimulating hormone (FSH) over a 3-day period to mature ovarian follicles. The amount of FSH administered was based on baseline serum FSH concentration in unmated New Zealand White does; as determined by radioimmunoassay. Treatment with FSH was followed by intravenous administration of human chorionic gonadotropin (hCG) to enhance ovulation. Hormonally primed does were then mated to mature, fertile bucks. Ova were collected 18 to 20 h after mating. This procedure resulted in an average yield of 37 ova/doe, with a 72.3% fertilization rate. These results were consistent with those published for superovulation using multiple subcutaneous injections of FSH. This method provided a consistent high yield of fertilized ova per doe and required only a simple surgical procedure.

Animals↗
PubMed1991

Immunomodulation in an apparently non-immunogenic murine tumor.

Madison lung carcinoma (M109), a murine tumor of spontaneous origin, appears to be non-immunogenic, according to 2 commonly employed tests for tumor immunogenicity. However, C.parvum-induced immunopotentiation during the growth of M109 tumor results in post-excision anti-tumor immunity to M109 tumor implants. The C.parvum-potentiated post-excision immunity to M109 is tumor-specific and T-cell-dependent. T cells from mice whose progressive M109 tumors have been excised are capable, on passive transfer, of inhibiting adoptive immunotherapy of T-cell-deficient recipients by spleen cells from mice immunized with an admixture of M109 cells and C.parvum. The data are interpreted as evidence supporting the hypothesis that the apparent lack of anti-tumor immunity in this tumor model is not due to the absence of tumor-associated antigens. We suggest that, instead, in this model the balance between the effector and suppressor arms of the immune response favors tumor-induced immunosuppression, resulting in a magnitude of anti-tumor immunity insufficient for detection by commonly employed tests for tumor immunogenicity. Our study shows that shifting the balance in favor of the effector arm by means of immunopotentiation results in a measurable immune response to an apparently non-immunogenic tumor.

Animals↗
PubMed1991

Effects of computerized nurse careplanning on selected health care effectiveness measures.

A computerized nurse careplanning system (CNCP) was implemented on two nursing units of the Veterans' Affairs Medical Center, Washington, DC. This pretest, post-test experimental study sought to determine the effects of implementing this system on selected nursing care activities and associated patient outcomes. Effects on outcomes of job satisfaction, use of careplanning and competency of staff nurses were also examined. The sample consists of four medical nursing wards with registered nurses (n = 40) and patients (n = 160 as subjects). Data collection included nurse questionnaires, patient interviews and chart reviews. Results of the multiple regression analyses will be summarized here. Plans for further enhancement of CNCP will be discussed.

District of Columbia↗
PubMed1989

An evaluation of intra-cage ventilation in three animal caging systems.

Although temperature and relative humidity have been quantitated and their effects on research data studied, few studies have measured the air turnover rates at cage level. We evaluated the air distribution and air turnover rates in unoccupied shoe-box mouse cages, filter-top covered cages and shoe-box mouse cages housed in a flexible film isolator by using discontinuous gas chromatography/mass spectrometry and smoke. Results showed that air turnover was most rapid in the unoccupied shoe-box mouse cage and slowest in the filter-top covered cage. Placing mice in the filter-top covered cage did not significantly improve the air turnover rate. Although filter-top covered cages reduce cage-to-cage transmission of disease, the poor airflow observed within these cages could lead to a buildup of gaseous pollutants that may adversely affect the animal's health.

Air Conditioning↗
PubMed1988

An evaluation of three anaesthetic regimes in the gray short-tailed opossum (Monodelphis domestica).

The effect of several anaesthetic agents on the gray short-tailed opossum (Monodelphis domestica) was investigated. Pentobarbitone sodium at a dose of 50 mg/kg sedated the animals but did not produce analgesia or anaesthesia. A combination of ketamine hydrochloride and xylazine at 40 mg/kg and 5 mg/kg, respectively, sedated the animals, but anaesthetic levels were not attained. Halothane was most effective in producing anaesthesia in Monodelphis domestica. Hypothermia was a major side effect with all three anaesthetic regimes.

Anesthesia↗
PubMed1987

Reproductive failure associated with cystic rete ovarii in guinea pigs.

Cystic ovaries were found at necropsy in 54 of 71 (76%) female guinea pigs between 18 and 60 months of age. Histologic appearance and location of the cysts within the ovary were consistent with cystic rete ovarii. Microscopic appearance of the large ovarian cysts suggested reproductive performance in these guinea pigs should be compromised. Breeding records indicated that fertility was markedly reduced in affected females over fifteen months of age. Cystic endometrial hyperplasia, mucometra, endometritis in appropriate placental tissue, or fibroleiomyomas were seen in 21 of 54 (39%) guinea pigs with cystic ovaries, but in only one of 17 (6%) guinea pigs without cystic ovaries.

Age Factors↗