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Biomedical subjects

A R Chang

Publications and source records attributed to A R Chang.

At least 37 records · Page 2Linked to original sources
PubMed1990

Carcinoma in situ of the cervix and its malignant potential. A lesson from New Zealand.

An overview of studies attempting to define the natural history of carcinoma in situ of the cervix suggests that 20-30% of lesions progress to invasive carcinoma within 5-10 years. This risk of invasion and the inability to predict when invasion might occur has been reinforced by a judicial enquiry in New Zealand so that protocols that include withholding treatment are no longer justifiable. Once a diagnosis of cervical carcinoma in situ is established appropriate treatment is mandatory.

Carcinoma↗
PubMed1990

Measurements of unsaturated vitamin B12-binding capacity and myeloperoxidase as indices of severity of acute inflammation in serial colonoscopy biopsy specimens from patients with inflammatory bowel disease.

Measurements of tissue content of myeloperoxidase, a constituent of neutrophil azurophil granules and of unsaturated vitamin B12-binding protein from neutrophil-specific granules, have been used to assess intestinal inflammation. This paper reports results of a prospective evaluation of such measurements in serial colonoscopy biopsy specimens from patients with inflammatory bowel disease. Histologic grading of acute inflammation was based on perceived numbers of neutrophil polymorphs in sections from an immediately adjacent biopsy specimen. The mean + 2 SD range for unsaturated vitamin B12-binding protein activity in homogenates of histologically normal specimens was 62 pg mg protein-1. Values increased progressively up to 900 pg mg-1 protein in the most severely inflamed specimens. Unsaturated vitamin B12-binding protein measurements generally distinguished among histologic grades of inflammation, whereas myeloperoxidase activities failed to do this, probably because substantial myeloperoxidase activity was found in uninflamed colonic mucosa, suggesting a non-neutrophil source for this enzyme.

Acute Disease↗
PubMed1989

The socioeconomic status of women attending a New Zealand colposcopy clinic.

An analysis of a group of predominantly Caucasian women with cervical intraepithelial neoplasia grade 3 lesions seen at the Dunedin Hospital Colposcopy Clinic during a period when it was the only colposcopic service in the region, showed that patients in the lowest socioeconomic class, as judged by two parameters unique in New Zealand were overrepresented. This finding is in agreement with the social class gradient for cervical cancer and precursor lesions observed in other countries. Poverty, more liberal sexual activity and smoking may be factors in the genesis of cervical neoplasia amongst the women studied. In providing cervical smear facilities for at-risk women, special provision should be made for women in the lowest social stratum.

Adolescent↗
PubMed1989

Hormonal contraceptives, human papillomaviruses and cervical cancer; some observations from a colposcopy clinic.

Observations from a colposcopy clinic from 1982-1985 are presented and show that in women with histologically proven precancerous lesions, those using hormone contraception had a significantly higher infection rate with human papillomavirus (HPV). Hormone contraception was preferred by younger women. Because information relating to sexual behaviour was not available for analysis, the findings in this study need to be interpreted with caution. The association of HPV and cervical cancers is well established. If hormonal contraceptive use and simultaneous HPV infection are associated with cervical neoplasia, and laboratory evidence supports this thesis, then further urgent investigations are needed for the implications are grave.

Adolescent↗
PubMed1989

An evaluation of cervical smears consisting of spatula and Cytobrush samples.

Analysis of 100 paired spatula and Cytobrush cervical smear samples taken and evaluated by one person showed that the combined smear was excellent for sampling the transformation zone and for detecting lesions. However, care in obtaining and evaluating smears are still vital if false-negative smears are to be eliminated. The greater use of the 2-sample smear is advocated.

Female↗
PubMed1985

An analysis of abnormal cervical smears at Dunedin Hospital 1963-82.

Analysis of the abnormal cervical smears seen in the Dunedin Hospital during the 20 year period 1963-82 showed a significant increase in abnormal smears in patients 34 years of age and younger during 1978-82. There were also a number of abnormal smears seen in teenagers; indicating early onset of sexual activity. The increase in abnormal smears is expected to continue; especially in the younger subjects and a one yearly screening programme for all sexually active females is advocated. The possible role of the human papilloma virus in cervical neoplasia is discussed.

Adolescent↗
PubMed1983

Rapid induction of gastric ulceration in guinea pigs by sequential exposure to a barrier breaker and indomethacin.

In short term experiments under halothane anesthesia, guinea pig total gastric pouches were initially and terminally exposed to 0.1 M HCl for 30 min. During an intervening 50-min test period, the gastric mucosa was exposed at pH 7.3, either to a barrier breaker (lysolecithin or diluted bile or sodium taurocholate) or to phosphate buffered saline (PBS) for half of the period, followed by exposure to indomethacin or further PBS for the second half of the test period. Scoring of mucosal damage was assessed from coded photographs and histological slides and by measurement of the transmucosal potential difference. In comparison with controls exposed only to PBS in the test period, indomethacin did produce minor but significant mucosal damage, whereas over this short time interval, the barrier breaking agents did not. Sequential exposure of pouches to lysolecithin and indomethacin caused a highly significant increase in ulceration, compared to controls or to indomethacin or lysolecithin exposure separately.

Animals↗