mechanism for the t4 lymphopenia of aids i suggest that the t4 lymphopenia of aids may be caused by antibodies raised against the human immunodeficiency virus that block the generation of t4 cells duodenal ulcer in systemic mastocytosis two cases of systemic mastocytosis are presented both patients had peptic ulceration greatly raised values on investigation of gastric acid secretion in patients with therapyresistant peptic ulceration and normal serum gastrin should raise the suspicion of systemic mastocytosis a dermatoglyphic survey of kenyan schoolchildren the article reports on progress in the analysis of data from a dermatoglyphic survey of 6235 kenyan schoolchildren drawn from some 60 ethnic populations the findings indicate considerable variation within kenya for a majority of dermatoglyphic traits examined often approaching the full subsaharan african range the examination of interpopulation relationships within kenya is complex owing to inconsistencies in population rankings both between phenetically unrelated traits and between the sexes moreover no appreciable clustering of populations along linguistic or ethnic lines was detected during multivariate investigation