Loss of heterozygosity of p53 gene of oral cancer detected by exfoliative cytology.

The p53 tumor suppressor gene is a 16-20-kb section of cellular DNA located on the short arm of human chromosome 17 at position 17 P 13.1. Allelic deletions and/or point mutations in p53 gene are now known to be associated with the development of carcinogenesis. A hallmark of p53 is that both alleles are generally altered during transformation, which usually represents a loss of heterozygosity (LOH). In this study 30 normal dental students and 22 oral cancer patients were collected from the affiliated hospital of Chung Shan Medical and Dental College, Taichung, Taiwan. Extractions of DNA from the buccal mucosa or cancer surface were sampled by cytology brush. The two polymorphic restriction sites exon 4 and intron 6 within the p53 gene were amplified with polymerase chain reactions followed by restriction fragment length polymorphism assay. In heterozygous individuals, 66% of oral cancers demonstrated loss of p53 gene heterozygosity at the exon 4 site, and 50% showed LOH at the intron 6 site. These results indicate that inactivation of p53 gene is associated with development and/or progression of oral cancer. The essential advantages of oral exfoliative cytology are the non-invasiveness, painlessness, rapidity, ease and cost-effectiveness of cell sampling and DNA extraction. Furthermore, this experimental assay might be useful for preliminary screening of carcinogenesis in human beings.

Neurologic and ophthalmologic findings in children exposed to cocaine in utero.

We studied a cohort of 73 children exposed to cocaine in utero to characterize the spectrum of neurologic and ophthalmologic abnormalities; 36 children with no documented in utero drug exposure were selected as a control group. Most referrals of cocaine-exposed children to the child neurologist were made in the 1st year of life (81%). Reasons for referral were hypertonia (29%), seizures (22%), developmental delay (11%), tremulousness (11%), and hypotonia (4%). The most common abnormal finding in the cocaine-exposed children was hypertonia/hyperreflexia (63%), which was rarely seen in the control group. In addition, hypertonia/hyperreflexia was underdiagnosed by referring physicians. Similarly, hypotonia was seen on neurologic examination of cocaine-exposed children more frequently than documented by referral (16% versus 4%). Hypotonia was rarely seen in the control group. Twelve (43%) of 28 cocaine-exposed children seen by a pediatric ophthalmologist had structural ophthalmologic abnormalities. Neurologic and ophthalmologic findings suggesting structural lesions of the nervous system must be considered in cocaine-exposed children.

[An epidemiological study of oral cancer in Taiwan].

Southeast Asia, which includes Taiwan, has one of the highest incidences of oral cancer in the world. From a public health or a clinical dental viewpoint, it is important to study the epidemiologic characteristics of oral cancer in Taiwan. This paper presents epidemiologic data on oral cancer in Taiwan from 1981-1986. The data, gathered from Cancer Registry Center, Department of Health, Executive Yuan, ROC, is studied using the descriptive method. The age-standardized incidence rates for males and females were 4.45/100,000 and 1.42/100,000, respectively. The cumulative incidence rate (0-79 years) was 0.59% for males and 0.19% for females, respectively. The average age was 52.0 years for males and 53.4 years for females. The male/female ratio was 3:1. The most frequently affected sites were the tongue for males and major salivary glands for females. The incident rates were found to be significantly higher in central Taiwan, especially for males. Epidermoid carcinoma was the most common histopathologic type of oral cancer for both sexes.

[Harlequin fetus--a case report].

A one-day-old male premature baby was born to a G4P4 mother with the gestation age of 30 weeks. His birth weight was 2000 gm. He was noted to be covered with a thick, armor-like skin which is split by deep fissures and makes the feature of Ectropion and eclabium. His nose was flattened, only the nostrils were visible, and the external ears were underdeveloped. The hands and feet appeared to be swollen and crumpled. The genital organ was covered with thick fissured skin and it was impossible to distinguish sex by external appearance. Three days after delivery, the patient died of respiratory distress. He was found normal through general laboratory and chromosome study. However, dermatohistology showed hyperkeratosis, focal parakeratosis and hypogranulosis. Pathology showed PDA (patent ductus arteriosus), enlarged thymus and congestion of internal organs. Its etiology and pathogenesis somehow remain unknown. We hereby reported this harlequin fetus, the most severe type of lamellar ichthyosis, and discussed its incidence, pathogenesis, pathohistology, prognosis and the recent development in treatment.