Biomedical subjects

J L Cowley

Publications and source records attributed to J L Cowley.

3 recordsLinked to original sources

PubMed1985

Luteal function in cows following destruction of ovarian follicles at midcycle.

Luteal function was studied in the absence of non-ovulatory ovarian follicles to determine if these follicles are involved in luteal regression in cattle. After at least one estrous cycle, cows were assigned randomly to treatment (n=5) or control (n=5). All cows were laparotomized on day 10 postestrus (Estrus = day 0). During laparotomy of treated cows, all visible follicles on both ovaries were destroyed by electrocautery, and follicular growth was prevented by ovarian x-irradiation. In controls, laparotomy and ovarian manipulation were as in treated cows but follicles were not destroyed and ovaries were not irradiated. On day 22 postestrus, ovaries of 4 treated cows contained no visible follicles and concentrations of estradiol-17beta in jugular plasma (0.4 +/- 0.1 pg/ml) were less (P<0.05) than in controls (3.2 +/- 0.4 pg/ml). Daily mean concentrations of LH from surgery to day 22 postestrus in treated cows did not differ from controls. On day 22 postestrus, progesterone in jugular plasma and weights of corpora lutea in treated cows were greater (P<0.05) than in controls. Between days 12 and 18 postestrus, concentrations of estradiol-17beta and PGF(2)alpha in utero-ovarian venous plasma of controls increased prior to detectable declines in concentrations of progesterone. Therefore, non-ovulatory ovarian follicles present during mid to late diestrus are necessary for luteal regression in non-pregnant cattle.

Journal Article↗

PubMed1984

Production of estradiol by each ovary during the estrous cycle of cows.

The objective of our experiment was to examine changes in serum concentrations of estradiol in each utero-ovarian vein before, during and after gonadotropin surges. Four cows were given prostaglandin F2 alpha (PGF2 alpha) during diestrus and three cows were allowed to cycle spontaneously. All cows had a cannula in each utero-ovarian vein and in one jugular vein. Most cows had two transient rises in estradiol, primarily coming from a single ovary, preceding and after luteinizing hormone (LH) surges. The first rise in estradiol began after luteal regression and was sustained from 48 h before a pre-ovulatory LH surge to the end of the LH surge. The second rise in estradiol was sustained from 72 to 168 h after the end of an LH surge. To determine how rapidly asymmetrical production of estradiol began during luteolysis, several cows were injected with PGF2 alpha during the luteal phase. Blood samples were taken from a jugular and both utero-ovarian veins at hourly intervals before and after PGF2 alpha. Asymmetrical production of estradiol began within 3 h after an injection of PGF2 alpha. We concluded: (1) that a single ovary was responsible for the sustained increases in concentration of estradiol that occur during proestrus to estrus and early diestrus in cows and (2) that cows may have at least one follicle capable of producing estradiol during most days of an estrous cycle, thus little delay in selection of which follicle eventually ovulates occurs after luteal regression.

Animals↗

PubMed1984

Matrix organization increases physician, management cooperation.

Because of the development of multihospital systems and the establishment of diagnosis related groups, hospitals increasingly will establish matrix organizations for their corporate structures. St. Luke's Hospital adopted the matrix concept in the mid-1970s, utilizing program administrators for each specialty service or "clinical center of excellence." Such centers have been developed in digestive diseases, cardiovascular and pulmonary medicine, orthopedics and rheumatology, ophthalmology, and behavioral health. The program administrator's functions are diverse: To serve as primary liaison between physicians and the hospital; To project levels of program utilization and patient and physician satisfaction, to identify areas requiring administrative and marketing emphasis, and to develop the program's marketing plan; To develop, implement, and evaluate the program's strategic, operational, and financial plans; To recruit physicians to practice at St. Luke's and to cultivate referrals from outside physicians; To participate in selecting members of all board and medical staff committees relating to the particular specialty area; and To determine the need for new programs within the specialty area and to develop services. As indicated by a medical staff survey, most physicians at St. Luke's believe that the program administrator system has improved communication with the hospital administration, that the program administrator is able to respond effectively to physician requests and problems, and that the quality of patient care has been enhanced. A great majority said they would recommend the system to other hospitals.

Arizona↗