Apoptosis, or programmed cell death, is a process fundamental to the homeostasis of multicellular organisms. Therefore, the development of methods for detecting dying and dead cells is of great importance. In the present study, four methodologies for identifying thymocyte apoptosis were evaluated and compared: a classical Haematoxylin and Eosin staining method, two histochemical methods (DNA polymerase-mediated in situ end-labelling and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end-labelling) and flow cytometry. Aspects important for the quantitation of apoptosis in the mouse thymus after a low dose (below 1 Gy) of X-ray irradiation were emphasized. The nick-end-labelling method had the highest sensitivity among the four methods in detecting apoptotic cells; however, the in situ end-labelling method showed sensitivity similar to nick-end-labelling and possessed better response to incremental increase in radiation. The sensitivity of the Haematoxylin and Eosin staining was lower than the above two methods. Flow cytometry could not detect low-frequency apoptosis after a low radiation dose of below 30 cGy (cGy = 0.01 Gy) and did not respond linearly to increasing radiation. We conclude, therefore, that the in situ end-labelling method is the most adequate of the methods tested, especially for the detection of low-frequency apoptosis.

Animals↗

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Statistical analysis of symptoms and signs in pediatric patients with peptic ulcer.

It is not well known which symptoms or signs related to peptic ulcer are crucial for its diagnosis in children. In order to clarify this problem, we evaluated the sensitivity, specificity, and positive and negative predictability of 13 ulcer-related symptoms and signs. The data of 160 patients, who were suspected of having peptic ulcer and had undergone endoscopic examinations, were studied. It was significant that five symptoms, i.e., presence of pain in the epigastrium, relationship between the time of pain and that of eating, family history, vomiting, and bleeding, were frequently found in ulcer patients. There was, however, no symptom or sign that predicted by itself precisely the existence of a peptic ulcer. Thus, we computed a discriminant function by combining the data by multivariate analysis. With this score, we could predict the existence of ulcer more precisely. Finally, it was concluded that epigastric pain, food-related pain, vomiting, bleeding, and family history were crucial factors for the diagnosis of peptic ulcer in childhood and that an overall consideration of symptoms and signs was needed for the evaluation of these factors.

Adolescent↗