PubMed Health⌕ Search

Biomedical subjects

E Gootwine

Publications and source records attributed to E Gootwine.

24 records · Page 2Linked to original sources
PubMed1989

Pituitary response to GnRH and ovariectomy in Booroola-Awassi and Awassi ewe lambs.

Booroola-Awassi ewe lambs were heterozygous (F+) for a major gene F, influencing their ovulation rate, while Awassi lambs were non-carriers (++). Basal plasma FSH concentration (mean +/- s.e.m.) in Booroola-Awassi ewe lambs at 4 weeks of age was significantly higher than in Awassi lambs of the same age (5.06 +/- 0.60 and 2.04 +/- 0.32 ng/ml respectively; P less than 0.001). After GnRH administration, FSH increased from 3.89 +/- 1.10 to 10.58 +/- 1.30 ng/ml in Booroola-Awassi (N = 6) and from 1.87 +/- 0.29 to 4.64 +/- 0.33 ng/ml in Awassi (N = 6) ewe lambs (P less than 0.05). Ovariectomy caused an increase in plasma FSH in Booroola-Awassi (N = 4) and Awassi (N = 4) ewe lambs. At 1 week after ovariectomy plasma FSH increased from 5.96 +/- 1.02 to 7.06 +/- 1.05 ng/ml in F+ and from 1.67 +/- 1.06 to 5.21 +/- 0.66 ng/ml in ++ ewe lambs, suggesting a stronger negative feed-back effect exerted by the ovaries of Awassi lambs. At 15 weeks after ovariectomy FSH values were similar in Booroola-Awassi (18.28 +/- 1.96 ng/ml) and Awassi (16.07 +/- 0.70 ng/ml) lambs. Although the overall pattern of pituitary response to ovariectomy was similar in the F+ and ++ ewe lambs, Booroola-Awassi lambs had small ovaries (132.5 +/- 24.9 mg) and follicular development did not proceed beyond the preantral stage in 3/4 animals, and Awassi lambs had large ovaries (600.0 +/- 233.9 mg) (P less than 0.05) with many preantral and antral follicles.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

Developmental potential of myeloid leukemia cells injected into midgestation embryos.

Cells from a clone of mouse myeloid leukemic cells that can be induced to differentiate in vitro to mature cells by the normal macrophage- and granulocyte-inducing protein, MGI-2, were injected into mouse embryos at 10 days gestation. The leukemic cells, derived from an SJL/J mouse, were microinjected into the placentae of C3HeB fetuses and the viable progeny were tested for chimerism by analysis of glucose phosphate isomerase isozymes. Fifty-five percent out of 201 viable progeny died prior to weaning due to tumors derived from the injected cells. Of the remaining 91 apparently healthy adult animals, 2 had chimeric populations. One mouse had a chimeric population of granulocytes and the other mouse a chimeric population of macrophages. The animal with a chimeric population of macrophages was chimeric at 1 and 2 months of age and had lost any detectable donor derived contribution by the age of 3 months. The chimeric granulocyte population in the other animal was still stable at 3 months. The myeloid leukemic cells injected into midgestation embryos thus participated in the development of two different cell types in apparently healthy adult animals. Our results indicate that malignant cells of more restricted developmental potential than teratocarcinoma cells may participate in normal development. It remains to be determined whether this participation in normal development was due to normal differentiation of the malignant cells, or the production of nonmalignant segregants derived from the malignant cells.

Animals↗
PubMed1983

Appearance of functional EGF receptor kinase during rodent embryogenesis.

Mouse and rat embryonic tissues at various stages of development were examined for epidermal growth factor (EGF) receptor kinase activity. The phosphorylated EGF receptor from embryonic tissues appeared as a band of mol. wt. 170 000 daltons on SDS gels. It was clearly demonstrable in the developing mouse fetus from 10 days of gestation onwards. The distribution of the EGF receptor kinase was studied in various tissues of 13 day mouse fetuses. The activity was apparent in the skin, developing skeletal muscles and various internal organs but was notably absent in the liver and brain. The amnion was found to be one of the richest sources of activity while the yolk sac was negative, and the placenta was weakly positive. In 16 day rat fetuses the distribution was quite similar to that of the 13 day mouse fetus. The liver acquired EGF receptor kinase activity by 18 days of gestation and had high activity in neonates. Phosphoamino acid analysis revealed that phosphotyrosine was the major labelled amino acid residue in the embryonic tissues. Thus, the EGF receptor of fetal tissues as studied by immune precipitation and phosphorylation appears to be a similar entity to that found in adult mammalian tissues. This functional EGF receptor kinase activity could first be detected at the time of onset of organogenesis.

Age Factors↗
PubMedDate not supplied

Non-clinical intramammary infection in lactating ewes and its association with clinical mastitis.

A bacteriological survey for the study of non-clinical intramammary infection in the sheep udder was carried out in 88 Assaf ewes. A mean infection prevalence in the first few weeks of lactation was 55%. The most common bacterial isolates were Micrococcus spp. followed by coagulase negative staphylococcus, together accounting for 93% of the total number of isolates. An infection prevalence of 54% was found in ewelambs 2 days after their first lambing, indicating a marked new infection rate around lambing. Generally, the course of lactation was characterized by dynamic changes of new infection and spontaneous resolution. About 5% of half udders examined developed clinical mastitis. The comparison of bacteriological data from mastitic milk samples and from samples taken from the same half udders before the appearance of the clinical disease could not support the theory that in sheep, mastitis is a clinical exacerbation of a non-clinical intramammary infection.

Animals↗