Epidemiologists in the United States: an assessment of the current supply and the anticipated need

We provide 1985 estimates of the work force of epidemiologists in the United States, the number of graduates from training programs in epidemiology, and a projection of the future need for these health professionals. Our methods included a search of mailing lists from professional organizations, mail contact with graduate training programs, telephone interviews with experts, and a review of job announcements in professional journals. The study indicates that the current work force of epidemiologists in the United States is estimated to include 4,600 persons, more than half of whom are physicians; most epidemiologists are located in either a state with a major federal public health agency or one with a large population; and programs in epidemiology graduate an average of 475 persons with one or two years of master's level education and approximately 80 with doctoral-level education each year. After considering the factors that influence the supply of epidemiologists, we project a substantial need for more epidemiologists in the future than current sources will provide.     

Vascular and soft tissue calcification in systemic oxalosis: CT diagnosis

Hyperoxaluria may result in diffuse deposition of calcium oxalate crystals in multiple organs. A patient with primary hyperoxaluria presented with peripheral ischemia on this basis. Computed tomography clarified the diagnosis and helped to direct the appropriate management.     

Incidence of cancer in the wilaya of Setif, Algeria

Preliminary results are presented for a general population-based cancer registry in Setif, Algeria, for 1986-88. Standardised incidence rates for all sites, excluding non-melanoma skin cancer, are 70.1 for men and 59.9 for women: these rates are lower than those reported for most populations. The most frequent cancers are lung, stomach and liver in men, and cervix, liver and breast in women. Nasopharyngeal carcinoma is frequent in both sexes. Incidence of cancers of the gallbladder and extrahepatic bile ducts in women appears particularly high. These results represent the first detailed incidence data for all cancers in an Algerian population.     

Chronic bullous disease of childhood--another cause for potential misdiagnosis of sexual abuse?

There have been several reports of unusual skin conditions producing genital lesions that can be mistaken for sexual abuse. We report on another unusual skin condition, well known to dermatologists, that can again lead to potential misdiagnosis of sexual abuse.     

Postnatal dendritic development of Y-like geniculocortical relay neurons.

We describe the dendritic development of neurons in the dorsal lateral geniculate nucleus (LGNd) projecting to cortical area 18 in the postnatal cat. LGN neurons were identified by retrograde labeling from area 18 with fluorescent latex microspheres and injected in the fixed slice with Lucifer yellow (LY) and horseradish peroxidase (HRP) to visualize their dendritic arborizations. Both topological (measures of the patterns of dendritic branching and their territorial coverage) and metric parameters (measures of the quantitative parameters describing the size, length, extent and diameter of the dendritic arbors) were measured in three-dimensions for 25 LGN neurons in cats between 1 and 18 postnatal weeks. In addition, dendritic growth was compared to the changing dimensions of the LGNd. At all ages, neurons projecting to area 18 have large somata and radiate dendrites. From 1 to 18 weeks neurons increase in size--both soma area and the length of all dendritic segments double during this period. Intermediate and terminal dendritic segments show comparable growth until 5 weeks. However, only terminal segments continue to grow significantly from 5 until 18 weeks. Dendrites become straighter during development, the angle between daughter branches decreases and dendritic segment diameter increases, with terminal segments showing a greater increase relative to intermediate segments. The density of dendritic appendages increases transiently at 5 weeks and a differential redistribution occurs, so that by 18 weeks dendrites further from the soma have a greater density of appendages than those near the soma. Some dendritic relationships remain invariant during development--intermediate segments are always shorter, thicker and straighter than terminal segments. During these changes however, area 18 projecting neurons maintain a constant number of primary dendrites and have, on average, a constant branching pattern. The relative volume of the LGNd occupied by an area 18 projecting neuron increases 2.4-fold between 1 and 18 weeks as the dendrites grow with the result that the coverage of a given point of the LGNd by dendrites of area 18 projecting nearly doubles from 24 to 45 neurons per unit volume. This increased net dendritic overlap provides a substrate for enhanced numerical synaptic divergence of the Y-cell pathway from a point source in the retina to the visual cortex.