BY intent and by design, the Ten-State Nutrition Survey (TSNS) of 1968-1970 was concerned with both undernutrition and overnutrition. One concern was caloric and nutrient insufficiency and the effects of inadequate nutrition on growth and development. A second concern was caloric excess, as reflected by the level of fatness, and especially the prevalence of obesity, in different socioeconomic groupings and in different population segments. In the design of the TSNS, it was obvious that weight alone—or even weight relative to height—was an inadequate measure of fatness. A child might be "overweight," yet of less than average fatness; another child or adult might be underweight, yet actually obese. Accordingly, two fatfold measurements (commonly but improperly called "skinfolds") were incorporated into the anthropometric program. One benefit of the TSNS may be seen in the fact that we now have nine-decade triceps or subscapular fatfold data on more than 40,000 individuals; nearly one half of them are American Negro (i.e., black), for whom scant data were previously available. A second benefit is that these new data are sufficient in scope to describe lifelong changes in fatness, including some phases not previously known in detail. A third benefit is the socioeconomic partitioning of fatness, showing both an economic-related fatness increase in the male at all ages and an economic "reversal" of fatness in the female at adolescence and beyond. The TSNS was conducted on a household and family-line basis, including both parents and their children.1 So we have the opportunity to compare true family-lines, parents and their children, brothers and sisters, and husbands with wives.

In sections of human dentine (carious and sound) and bone examined with the electron microscope, apatite crystallites were seen to present long thin profiles somewhat suggestive of a cylindrical shape, broad profiles indicative of a plate-like shape, and profiles intermediate between these two extremes. With a special stereoscopic specimen holder allowing the specimen to be tilted through an angle of 30 ° it was possible to record images of two profiles of the same crystallite from different angles and thus gain information concerning the 3-dimensional morphology of crystallites showing a thin profile. In all fields so examined, the thin-profile crystallites that were properly oriented with respect to the axis of tilt exhibited a different width dimension in each of the two micrographs. From this it is concluded that the thin profiles actually represented edge views of plate-like crystallites.

No abstract

No abstract

In the process of dentinal caries both the organic and the inorganic components of the tissue are ultimately destroyed and eliminated, with resulting cavitation. Since ultrastructural studies of dentin in various stages of decay should almost certainly contribute importantly to a better understanding of the carious process, an electron-microscopic survey of carious dentin was undertaken in our laboratories.A number of papers have already appeared dealing with electron-microscopic observations on both artificially demineralized and undecalcified carious dentin. The distribution of micro-organisms in the carious lesionl-5 and the presence of typical cross-striated collagenous fibrils in the matrix1' 2 have been described. Lenz6 found large calcified bodies in dentinal canals, but, to our knowledge, no detailed information concerning the mineral phase of carious dentinal matrix has been reported. This paper deals with soft carious dentin presumed to be in an advanced state of decay. The character and distribution of the mineral moiety (apatite crystallites) of carious dentinal matrix are described. Dense mineral deposits lacking a collagenous matrix are also reported at the periphery of the dentinal canals. Finally, the appearance of the collagenous fibrillar component of carious dentinal matrix is described as it appears in sections stained with phosphotungstic acid and in homogenized tissue. The implications of certain of these findings as they relate to the carious mechanism are discussed. MATERIALS AND METHODSPermanent human teeth with apparently active carious lesions were obtained from the Dental Clinic of Strong Memorial Hospital, Rochester, New York. The whole teeth or soft carious materials excavated from carious lesions were fixed immediately after operative removal in cold (40 C.) 1 per cent osmic acid solution containing sucrose (0.22 M) and buffered to pH 7.2-7.4 with 0.025 M veronal acetate buffer, in neutral 10 per cent formalin, or in 70 per cent alcohol. Some of the material was dehydrated in alcohol and imbedded in butyl methacrylate catalyzed with 1 per cent benzoyl peroxide. Some material was stored in 70 per cent alcohol and sectioned without further treatment. A few observations were also made on fresh, untreated tissue. Sections were cut with a microtome* equipped with a glass knife.