Seasonal analysis of 1239 captive births of Siberian tigers (Panthera tigris altaica) indicated a peak in April to June (P less than 0.001). Studies on seven animals in Minnesota indicated that behavioral heat cycles and ovarian follicular phase cycles began in late January and ceased in early June. Behavioral observation of 12 heat cycles in four tigers yielded an estrous length of 5.3 +/- 0.2 days and an interestrous interval of 25.0 +/- 1.3 days. Hormone assays on weekly blood samples (N = 180) from three female tigers indicated 16 cycles in two breeding seasons. Peak estradiol-17 beta levels were 46.7 +/- 6.0 pg/ml (N = 17) and interestrous concentrations were 8.7 +/- 0.66 pg/ml (N = 28) during the breeding season. Anestrous estradiol levels were 4.2 +/- 0.5 pg/ml (N = 70). The interestrous interval between estradiol peaks was 24.9 +/- 1.3 days (N = 9) with two outliers of 42 days. Serum progesterone concentrations from February to June were 1.2 +/- 0.15 ng/ml (N = 32), providing no evidence for ovulation or corpus luteum formation. Luteinizing hormone (LH) levels were 0.56 +/- 0.04 ng/ml (N = 180). Serum testosterone (r=0.71, P less than 0.001) and androstenedione levels (r=0.75, P less than 0.001) were correlated with estradiol during the breeding season. The duration of anestrus was 8 mo in two of these tigers. The interval was shortened in one tiger by exposure to a 16L:8D photoperiod. The Siberian tiger appears to be a polyestrous seasonal breeder and an induced ovulator whose breeding season may be synchronized by photoperiod.

Androstenedione↗

PubMed1984

Carcinoma of the gallbladder.

Carcinoma of the gallbladder does not present with any specific signs or symptoms, frequently mimicking benign gallbladder disease. Thus the diagnosis often is not made pre- or intraoperatively. A retrospective review of the Louisiana State University Medical Center-Shreveport experience was done to evaluate stage at diagnosis, therapy, and outcome. Thirty cases of gallbladder carcinoma were diagnosed between 1952 and 1982. The mean age of the patients was 67.4 years with 23 women and seven men. Six patients had the diagnosis made only after final pathologic examination of the specimen and had a mean survival of 7.4 months. Only three patients had the diagnosis made at operation with the tumor localized and the procedure thought to be curable with a mean survival 13.0 months. A biopsy alone or autopsy diagnosis was performed in 11 patients and a palliative procedure done in ten patients, with mean survival 0.9 months and 3.6 months, respectively. Successful surgical therapy is usually more fortuitous than planned. Surgeons must maintain a high index of suspicion and obtain frozen section diagnosis of any suspected tumor.

Adenocarcinoma↗

PubMed1983

How bad were the good old days?

Explore the source record for details and available documents.

Education, Medical↗

PubMed1981

Quality control in pediatrics.

The origin, growth, and development of the American Board of Pediatrics throughout 45 years is traced. The principles that have guided and the problems overcome in the establishment of an acceptable mechanism for primary certification are discussed. Relevance to the process of developing a mechanism for recertification is suggested.

Adult↗

PubMed1980

Survey of pediatricians certified by the American Board of Pediatrics up to 1975.

Explore the source record for details and available documents.

Canada↗

PubMed1976

A method for defining competency in Pediatrics.

In 1972 the American Board of Pediatrics (ABP) initiated studies leading to a report which identifies the important components of competency needed in the practice of pediatrics. The development of the report involved a group process engaging ABP board members and examiners. The outcome has been (a) the delineation of a process for establishing definitions of competency in a medical discipline; (b) the development of a framework for specifying the abilities needed to perform the tasks required of pediatricians; (c) an elaboration of samples of pediatric subjects to which these abilities and tasks are relevant; and (d) the development of a basis for choice of methods to use for purposes of certification.

Certification↗

PubMed1974