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Biomedical subjects

M Stanton

Publications and source records attributed to M Stanton.

At least 19 recordsLinked to original sources
PubMed1992

Combined inter-observer and inter-method variation in bone histomorphometry.

Manual methods for the measurement of bone biopsies have largely been superseded by semi-automatic computerised techniques. Histomorphometrists often use control data obtained by other observers using different methods, thus combining inter-observer and inter-method variation. We have examined the combined effect of inter-method and inter-observer variation on measurements of bone area, osteoid perimeter, and osteoid width in iliac crest biopsies from healthy subjects, one observer using the manual grid system and the other using a semi-automated technique. Inter-observer and inter-method variation were independently determined, and the proportion of each expressed as a percentage of combined error. Our results indicate that the combination of inter-method and inter-observer variation causes significant differences in the values obtained for osteoid perimeter, whereas inter-method variation is mainly responsible for differences in osteoid width values; differences in bone area are largely due to inherent sampling variation. These variations indicate that caution is required when comparison is made with control data from other sources, especially if different techniques are employed.

Analysis of Variance↗
PubMed1989

Treatment of homosexual alcoholics in government-funded agencies: provider training and attitudes.

Alcoholism treatment providers in 36 government-funded agencies in New York City were surveyed for information about their training for and attitudes toward the treatment of homosexual patients. The 164 respondents had limited knowledge about how to evaluate and treat homosexual alcoholics and frequently did not discuss sexual orientation with their clients even though they considered it important. The training and supervision of most providers in the treatment of alcoholic homosexual clients was substandard or nonexistent. About half of the providers believed that treatment programs would benefit from having openly gay staff and felt that being openly gay carried little professional risk. Respondents also reported that development of programs for homosexual alcoholics had little priority in their facilities. Many believed that homosexual alcoholics are less likely to seek help and may have more difficulty achieving sobriety.

Adolescent↗
PubMed1984

Age of first appearance of simultaneous and successive negative contrast in infant rats.

Simultaneous (SimNC) and successive negative contrast (SNC), two paradoxical effects that are related to shifts in reward magnitude, were studied in rats from 11 to 17 days of age. Experiments 1 and 2 looked at the emergence of SimNC at 11, 14, and 17 days. At all of these ages, rats were able to discriminate between the large (milk suckling) and small (dry suckling) reward odor cues as measured by attachment latencies, but only the 14- and 17-day-olds showed SimNC. At none of the three ages was a discrimination formed to the differential odor cues in the alley in terms of runway speeds. Experiment 3 was designed as a further test of the absence of SimNC at 11 days. In this experiment, the pups were placed directly on the dam's ventrum to facilitate attachment. As in the earlier experiment, the 11-day-old pups discriminated between the odors signaling the two reward conditions but did not show the SimNC effect. In Experiment 4, SNC was measured in pups 14 and 17 days of age. SNC was shown at 17 days but not at 14 days in the attachment latency measure and at neither age in the run measure. These four experiments extend our earlier findings that the paradoxical effects that emerge out of intermittent schedules of reward magnitude occur earlier than those associated with single abrupt shifts in reward magnitude.

Aging↗
PubMed1981

Adjustment of weanling and adolescent rats to a reward condition requiring slow responding.

The effects of a schedule of discontinuously negatively correlated reinforcement (DNC), in which only approach responses that take 5 sec or longer are reinforced, were studied in weanling rats that began training at 18 days of age and adolescents that began training at 60 days. Yoked partially reinforced subjects (PRF) received rewards on the same trials as corresponding DNC subjects of the same age, whereas continuously reinforced subjects (CRF) were rewarded on all trials. At the end of DNC training (210 trials), the older but not the younger DNC subjects were running slower than their yoked-PRF controls. The results are consistent with development of inhibition and suppression related to the developing brain, particularly the hippocampus.

Adaptation, Psychological↗
PubMed1980

Ultrastructural observations on preneoplastic epidermoid metaplasia in the lungs of rats.

Epidermoid metaplasia, of a type that consistently progresses to epidermoid carcinoma, was induced in rats at the interface of pulmonary tissue and intrapulmonary deposits of beeswax that contained either benzo(alpha)pyrene or the heptane-soluble fraction of cigarette smoke condensate. The preneoplastic epithelium was searched for morphological harbingers of neoplasia and compared with the type of reactive bronchial metaplasia, rarely associated with cancer, that results from chronic murine pneumonitis. The carcinogen-laden beeswax caused both proliferation and migration of epithelial cells from bronchi adjacent to the wax deposits. These initial proliferating cells were characterized by a lack of differentiation and were similar to the basal cells of bronchial epithelium. The migrating epithelium rapidly established itself at the interface of wax and viable lung tissue as a highly differentiated, stratified squamous epithelium. This epithelium was not qualitatively different from normal squamous epithelium. However, quantitative differences were evident from both normal epithelium and the metaplastic epithelium resulting from nonspecific injury. In the preneoplastic epithelium, the first indications of aggressive behavior occurred in foci of dysplastic basal cells that sent cytoplasmic intrusions through defects in the basement membrane. Characteristically, these dyplastic basal cells had numerous infoldings of the nuclear membrane and prominent nucleolar alterations. All strata of preneoplastic cells contained excessively complex interdigitations of the plasma membrane and unusually large numbers of desmosomes and tonofilaments. In contrast, the nonspecific metaplastic epithelium consisted almost entirely of multilayered uniform cells that closely resembled immature but otherwise normal basal cells of respiratory epithelium.

Animals↗
PubMed1977

Calcium and magnesium contents of malignant hyperpyrexia-susceptible human muscle.

The calcium and magnesium contents of muscle obtained by muscle biopsy of patients referred for malignant hyperpyrexia screening were determined. The susceptibility to malignant hyperpyrexia was made on the basis of the halothane contracture test. No difference in cation concentrations was found between the normal and malignant hyperpyrexia-susceptible groups.

Adolescent↗