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Biomedical subjects

A M Schmidt

Publications and source records attributed to A M Schmidt.

At least 127 records · Page 7Linked to original sources
PubMed1988

Serum concentrations of oestradiol and progesterone, and sexual behaviour during the normal oestrous cycle in the leopard (Panthera pardus).

Three mature nulliparous female leopards were studied for 5 years. During three separate 6-month periods serum oestradiol and progesterone concentrations were measured at weekly intervals. Oestradiol was elevated over 21 pg/ml for 54 weeks during these 3 periods, and 36 oestradiol peaks (65.8 +/- 6.3 pg/ml (mean +/- s.e.m.), range 21-172 pg/ml) were identified. Daily frequency of feline reproductive behaviours averaged over each week increased from 1.9 +/- 0.2 (n = 93) during weeks with low serum oestradiol concentrations (less than 21 pg/ml) to 5.3 +/- 0.6 (n = 54) during weeks when serum oestradiol concentrations (greater than 21 pg/ml) were high. Increased serum progesterone concentrations (13-98 n/gml) were observed on 5 occasions in 2 leopards housed together. These presumptive luteal phases lasted from 1 to 5 weeks. Baseline progesterone values were 1.6 +/- 0.4 ng/ml (n = 131). No progesterone increments were observed in isolated animals, and serum concentrations remained at baseline levels. These limited observations suggest that female leopards do not require intromission to induce ovulation and luteal function. The average interval between oestradiol peaks for cycles with no progesterone increment was 3.4 weeks (range 1-6 weeks). The interval for the 3 complete cycles associated with elevated progesterone concentrations was 7.3 weeks. Analysis of sexual behaviours over the 5-year study period revealed no evidence of seasonality in these captive leopards.

Animals↗
PubMed1986

Cisplatin and vinblastine chemotherapy for metastatic non-small cell carcinoma followed by irradiation in patients with regional disease.

Forty-four patients with non-small cell carcinoma of the lung were treated every 3 weeks with vinblastine (4 mg/m2/day iv X 2) and cisplatin (20 mg/m2/day iv X 3). Of the 28 patients with metastatic disease, eight (29%; 90% confidence interval of true response, 17%-47%) achieved objective response, for a median duration of 27 weeks. Median survival in this group was 47 and 28 weeks for responders and nonresponders, respectively. Of the 16 patients with advanced regional disease, 11 (69%; 90% confidence interval of true response, 49%-86%) achieved objective response. Thirteen of these patients received consolidation radiotherapy (4500 cGy/25 fractions/5 weeks), with a boost of 1000 cGy/5 fractions/1 week in those patients who achieved response. In the three patients who did not receive radiotherapy, two died during the induction phase, one from grade 4 leukopenia and sepsis and the second from unrelated factors. The third patient had systemic progression of disease during induction chemotherapy. Six patients experienced overall improvement in their chemotherapy response from the radiotherapy. Two patients who did not respond to the chemotherapy achieved partial response with irradiation. Four patients who had partial response to the chemotherapy achieved complete response with irradiation, and seven patients had no further change in their degree of response to irradiation. The overall median survival of this group was 81 weeks. Maintenance chemotherapy was not given. After radiotherapy, the site of first failure was outside the radiation field in nine of 13 patients (69%). Hematologic toxicity was dose-limiting. Other toxic effects that were not dose-limiting included nephrotoxicity, neurotoxicity, and acute nausea and vomiting. In the patients with advanced regional disease, there was no increase in the radiation toxicity attributable to the chemotherapy. We conclude that: (a) this dose schedule of vinblastine and cisplatin has reproducible activity in non-small cell carcinoma of the lung; (b) the response and median survival of patients with advanced regional disease are superior to those of patients with metastatic disease; and (c) in patients with advanced regional disease, treatment with chemotherapy followed by radiotherapy yielded an overall response rate of 81% (90% confidence interval of true response, 60%-93%) and improved survival compared to a similar group of patients studied by others receiving radiotherapy alone. We recommend further testing of this concept.

Adult↗
PubMed1984

Phase II trial of cyclophosphamide and cis-platinum for non-small cell bronchogenic carcinoma.

We hypothesized that cyclophosphamide and cis-platinum, without adriamycin, which had been used in previous studies, may be equally efficacious, but less toxic. We treated 27 patients with non-small cell bronchogenic carcinoma with the combination of cyclophosphamide and cis-platinum. We report six responses (25% response rate), with median survival of 79 weeks as compared to 28 weeks in nonresponders (p less than 0.01). Our regimen had acceptable hematologic toxicity and tolerable gastrointestinal toxicity. However, cumulative nephrotoxicity and neurotoxicity were observed. We conclude that cyclophosphamide and cis-platinum may compare favorably to the cyclophosphamide, adriamycin and cis-platinum combination, with respect to response and toxicity.

Adult↗
PubMed1979

Serum concentrations of oestradiol and progesterone during the normal oestrous cycle and early pregnancy in the lion (Panthera leo).

During a 6-month study period weekly serum samples demonstrated 9 oestradiol surges above 14 pg/ml (range 19-108 pg/ml) among 3 lionesses isolated from male lions. Intervals between peaks ranged from 3 to 8 weeks. Progesterone surges of more than 17 ng/ml (range 17-282 ng/ml) and lasting for 2-6 weeks were recorded after 7 of the oestradiol peaks. Sexual behaviour correlated well with the oestradiol peaks. Except for cornification following oestradiol peaks, there was no obvious vaginal cytology pattern at other times of the cycle. Pregnancy occurred after a 12-h contact with a male during behavioural oestrus. During gestation (108 days) oestradiol values remained low, while progesterone was elevated to 49 ng/ml within 12 h after mating, reaching a peak of 143 ng/ml at the 4th week, and remaining elevated during the next 2 months.

Animals↗