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Biomedical subjects

J F Hasler

Publications and source records attributed to J F Hasler.

At least 19 recordsLinked to original sources
PubMed1992

Current status and potential of embryo transfer and reproductive technology in dairy cattle.

Significant use of embryo transfer in dairy cattle commenced with the introduction of nonsurgical embryo recovery in the mid-1970s and developed with the use of nonsurgical transfers in the late 1970s. Numbers of registered Holstein calves from embryo transfer doubled yearly through 1980, after which the rate of increase slowed; the total reached nearly 19,000 calves in 1990. However, the efficacy of superovulation procedures and commercial success rates of transferred fresh embryos have not improved the past 10 to 15 yr. Fertilization rates in superovulated donors remain low. Although embryo-splitting techniques were perfected in the early 1980s, they are not used widely. A practical, commercial embryo-sexing procedure remains unavailable. Recent significant improvement is apparent in the technology of ultrasound-guided oocyte collection and in vitro oocyte maturation, fertilization, and embryo culture. In the future, this technology may be used in conjunction with sperm separated by sex with a flow cytometer. Modest numbers of embryo clones have been produced in several commercial programs via nuclear transfer techniques. However, the efficiency of gene transfer experiments involving ova of cattle and other domestic species has been low. Recently, DNA probe technology has begun to provide genotype information for cattle and will ultimately be applied to embryos.

Animals↗
PubMed1987

Occult radiopaque jaw lesions in familial adenomatous polyposis coli and hereditary nonpolyposis colorectal cancer.

The purposes of this study were to determine the association, in 10 pedigrees, between adenomatous polyposis coli, hereditary nonpolyposis colorectal cancer, and occult radiopaque jaw lesions, and to assess whether these radiodensities are predictors for adenomatous polyposis. In seven kindreds with adenomatous polyposis, all patients with polyps had jaw lesions; in one kindred, no jaw lesions were found. In one of two kindreds with hereditary nonpolyposis colorectal cancer, no affected individuals had jaw lesions. In the other, the 1 affected patient with dental radiographs had generalized jaw lesions. Twelve children less than 16 yr old at risk for adenomatous polyposis were observed. Seven children with jaw lesions developed polyps after a mean interval of 4 yr. Five children without jaw lesions were polyp-free during a 5-10-yr follow-up. Thus, occult jaw lesions are consistently found only in some families with adenomatous polyposis coli, providing support for heterogeneity in polyposis syndromes. Jaw lesions are good predictors for polyp development in kindreds with adenomatous polyposis coli and jaw lesions. Their role as markers in hereditary nonpolyposis colorectal cancer needs exploration.

Adenomatous Polyposis Coli↗
PubMed1986

The isolation of fungi from laboratory dental pumice.

Samples of used dental laboratory pumice from the two dental laboratories were cultured for the isolation of fungi. The resulting supernatant fluid from sedimentation of each pumice sample after suspension in sterile saline was serially diluted and plated onto Sabouraud agar. After incubation, fungal colonies observed were enumerated, isolated, and identified. The mean number of fungal colonies recovered from 10 pumice samples in laboratories I and II was 51.0 X 10(2) and 22.6 X 10(2), respectively. In both laboratories the predominant fungi recovered were Aspergillus niger and Fusarium sp. Other fungi recovered included Cephalosporium and Penicillium species and A. flavus. Many of these organisms have been involved in human disease. It is suggested that the presence of fungi in used dental laboratory pumice presents an unhygienic condition in the dental laboratory and may place dental laboratory technicians and denture patients at increased risk of fungal sensitization and disease.

Aspergillus niger↗
PubMed1983

Searching for markers in the hereditary intestinal polyposes.

Oral abnormalities in the intestinal polyposes have been reported by numerous authors. Detection of occult osteomatous and other dental changes in the jaws before development of polyps would be of considerable importance in the early diagnosis of premalignant gastrointestinal disorders. More than 425 individuals from families in whom intestinal polyposis is segregating have received oral-facial examinations. The dental findings may permit early, noninvasive identification of individuals at risk for polyposis.

Adolescent↗
PubMed1983

Acinetobacter contamination of laboratory dental pumice.

Micro-organisms of the genus Acinetobacter, implicated as opportunistic pathogens, have been recovered from dentures after laboratory repair. A study was undertaken to determine if Acinetobacter could be isolated from used dental pumice. Cultural studies demonstrated that Acinetobacter calcoaceticus variety lwoffi was present in high numbers in used pumice and was a major gram-negative microbial contaminant.

Acinetobacter↗
PubMed1982

Parotid enlargement: a presenting sign in anorexia nervosa.

The purpose of this article is to present the pertinent medical and dental features of anorexia nervosa and to add an additional oral-facial finding, parotid gland enlargement, which has been described infrequently in a few scattered reports. Pertinent differential diagnoses for the systemic and oral-facial findings are discussed, including a review of the factors producing salivary gland enlargement. Early recognition of the psychiatric and pathophysiologic components of this disorder are essential to diagnosis and successful treatment. The dentist should consider the diagnosis of anorexia nervosa in the presence of such abnormal dental findings as perimylolysis and chronic salivary gland enlargement, especially in underweight and amenorrheic young women.

Adolescent↗
PubMed1982

Milk progesterone concentration and production in superovulated Holstein cows.

Six Holstein cows in a commercial herd (three superovulated and three controls) and eight Holstein cows superovulated a total of 12 times in an experimental herd were studied. Superovulation was induced primarily by treatment with follicle stimulating hormone and prostaglandin F2 alpha. Milk was weighed twice daily for 30 days following treatment in the commercial herd with no effect on production. Milk samples were saved on Monday, Wednesday, and Friday to determine progesterone content. Last milk at mid-cycle averaged 8.2 ng/ml of progesterone for the cows in the experimental herd, and 7 days after superovulation they averaged 52.6 +/- 10.2 ng/ml (mean +/- standard error) of progesterone. The correlation with number of embryos recovered was .86. Therefore, milk progesterone may be useful in monitoring superovulatory response. Also, injection of prostaglandin F2 alpha into superovulated cows 9 days after a previous injection did not initiate a new estrous cycle, a fact accurately monitored by milk progesterone determinations.

Animals↗
PubMed1982

Resolved: that a fifth year of dental education be a requirement. Remarks for the affirmative.

Evidence has been presented that leading deans of dental schools and leaders of the AADS support the assertion that the current four-year dental curriculum is overcrowded. Furthermore, it has been shown that the magnitude of the problem of overcrowding is regarded as serious and has been so recognized for at least twenty years. Evidence was also presented that educators, students, and the practicing profession support the assertion that the current four-year curriculum does not prepare students adequately for dental practice. Evidence was then presented that the overcrowding and inadequacies of the current curriculum cannot be corrected by merely manipulating or restructuring curricular elements within the context of predental and four years of predoctoral education. Finally, it was shown that, in the opinion of educators and students, the overcrowding and inadequacies of the current four-year curriculum can be overcome by establishing a fifth year of dental education as a requirement.

Clinical Competence↗
PubMed1980

Serum progesterone concentrations in cows receiving embryo transfers.

Progesterone concentrations in systemic blood were determined by radioimmunoassay in crossbred cattle used as recipients in an embryo transfer programme. An embryo was transferred surgically to the uterine horn of 528 females which were in oestrus within one half-day of the donor. Jugular blood was obtained at the time embryos were transferred (3-7 days after oestrus) and again from most females between Days 9 and 14. Pregnancy was determined by rectal palpation 45-65 days after oestrus. There were no significant differences between serum progesterone levels of females which remained pregnant and those which did not. Out of 177 pregnant recipients, none had serum progesterone levels less than 0.5 ng/ml on Days 10, 11, or 12 but in 8, values were less than 1.0 ng/ml. Blood samples were also taken on Days 20, 21, or 22 from 113 of these recipients. The mean +/- s.e.m. concentration of progesterone in the pregnant females (5.14 +/- 0.34 ng/ml) was significantly higher (P less than 0.001) than in the non-pregnant females (1.17 +/- 0.25 ng/ml). The correlation coefficients between progesterone levels on Days 3, 4, 5 or 6 and 10-12 ranged from 0.18 to 0.37 (all P less than 0.02). Progesterone levels were not related to length of the previous cycle, the time of day an animal was first noticed in oestrus or the side of the corpus luteum. However, cows with a short oestrus had higher progesterone levels on Days 3-7 (P less than 0.01) than those in oestrus for a longer time.

Animals↗
PubMed1980

The reliability of new patient screening data.

Screening is an important component in selecting patients for predoctoral dental education, particularly in maintaining compatibility between a system of comprehensive patient care and each student's individual departmental requirements. To meet these goals it is necessary that the information obtained at screening be a reliable predictor of the ultimate treatment plan. This paper evaluates the reliability of screening by comparing original screening data to the final treatment plan. The results indicate that there is a significant positive correlation between screening and treatment planning data. When screening data can reliably identify the dental needs of school clinic patients, the goals of accurate assignment, comprehensive care, and student requirements can be achieved in the process.

Comprehensive Dental Care↗