Objective: Total body and lumbar spine bone mineral density (BMD-TB, BMD-L) and total body bone mineral content (BMC-TB) were measured to establish the course of bone demineralization in anorexia nervosa and the clinical factors in¯uencing BMC-TB and BMD changes during treatment. Method: Forty-two girls with DSM III-R anorexia nervosa, age 14.7t2.4 years. BMC-TB, BMD-TB and BMD-L were measured in approximately 7-month intervals for 27.8t4.1 months using DXA. Results: Despite nutritional improvement, there was an initial decrease of BMD-L, and no change in BMC-TB and BMD-TB. an increase in BMC-TB and BMD was observed after approx. 21 months from the beginning of the study.
Candidate carbon fiber reinforced carbon (CFRC) porous implant materials were evaluated for tissue compatibility in a rat model. Six different CFRCs of constant pore size (about 30 microm) were fabricated that had 9, 12, and 17% porosity with 2-nm3 matrix crystallites and 6, 12, and 20% at 25 nm3. They were implanted as femoral transverse diaphyseal pins that were 1.5 mm in diameter. At 5 and 45 weeks, implant and bone histologic specimens were evaluated histologically and by a scanning electron microscope and an electron microprobe. Also, regional lymph nodes and spleens were examined. By 45 weeks, direct implant-bone contact was observed over most of the interface in most specimens. At the implant surface, there was partial replacement of CFRC with host tissue. However, the microprobe showed that the implant-bone interface was chemically abrupt with no cross-diffusion of ionic species. Besides the surface effects, there was partial filling of the implant pores with tissue, including bone organized de novo deep within. This was observed histologically and confirmed by microprobe. Lymph nodes and spleens were histologically normal, and no carbon particles were found. None of the results were influenced by porosity or matrix crystallite size over the ranges studied. In summary, these porous CFRCs are partially degraded when in contact with bone and appear substantially tissue compatible. They may be useful as scaffolds for regrowth of bone.
There is evidence that the renal collecting tubule is involved in the final concentration of urine, but the fact that its wall is built up of two different kinds of cells has not hitherto been taken into account. The possible r6le of one of these, the "dark" cell, has been investigated by quantitative and qualitative methods. Collecting tubules were isolated by digestion in collagenase from the kidneys of normal rats and of rats deprived of water for 48 hr.; the dark cells were identified by staining with the Nitro BT method for succinic dehydrogenase. The number of dark cells was counted; the tubules were classified on a percentage basis into three groups, containing less than 30, 30-50, and more than 50 dark cells respectively; cytological and cytochemical observations were also made. It was found that both quantitative and qualitative changes occurred in the dark cells of the dehydrated rats. It seems that these cells secrete into the tubule lumen. It is suggested that collecting tubules may differ from each other functionally. The results are discussed in relation to Ginetzynski's hypothesis that ADH causes hyaluronidase to be secreted into the collecting tubule.THE view that the collecting tubule takes an active part in the concentration of urine rests upon two kinds of evidence. There is first, the measurement of osmotic pressures of tubular fluids obtained by micropuncture methods as reported by Wirz [1957] and Gottschalk and Mylle [1959]; and second, the histological and histochemical approach as typified by the work of Ginetsynski. In 1954 he reported that urine contains hyaluronidase and that more is present during osmotic diuresis. Later Ginetsynski [1958] described histological and histochemical investigations on the kidneys of rats deprived of water or injected with antidiuretic hormone (ADH); the mucopolysaccharides in the basal membranes of the collecting tubules became depolymerized and surrounding lymphatics were dilated. He concluded that ADH acts by stimulating the collecting tubule epithelium to produce hyaluronidase which depolymerizes polysaccharides in the tubule walls and surrounding connective tissue. They become permeable to water, which leaves the tubule and enters the lymphatics.
Better conditions for osteoblast phenotype expression on T after 7 days of culture coincided with greater adhesion and spreading of cells after 24 h on T, as compared with S. The initial contact of cells with underlying surface may influence osteoblast functions and possibly, bone regeneration and implant osteointegration in vivo. Early cell spreading may be an indicator of further expression of osteoblast phenotype and may be important for application of osteogenic cells in reconstructive surgery.
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