Operative and non-operative treatment of rachitic lower extremity deformities. A long term study with forty-six year average follow-up.

The long term sequelae of rachitic deformities includes degenerative arthritis. Surgery at an early age will be beneficial in preventing degenerative arthritis in children with severe deformities. Of the many metabolic processes involved with Vitamin D, there must be some that vary quantitatively so that a small alteration may produce rickets in one child, go completely unnoticed in another, and persist in still another as a subclinical disease. Furthermore, it is entirely probable that some children then diagnosed as having classical D-deficiency rickets, in fact, would now be found to have D-resistant states.     

The characterization of lodoxamide,a very active inhibitor of mediator release,in animal and human models of asthma

A most active biologue of disodium cromoglycate (DSCG) available, lodoxamide tromethamine (LT), has been studied and characterized pharmacologically, in animal and human models of asthma. It has self-tachyphylaxis, but has oral activity (lodoxamide ethyl) in rats, primates, and man. In rats (LT) was 2,500× more active than DSCG (ID₅₀=0.001 mg/kg), in primates the drug was also active by several routes (inhalation 1 g/kg, IV 0.001 mg/kg, and oral 10 mg/kg). In isolated rat peritoneal mast cells, the compound displayed a biphasic dose response inhibition to histamine release initiated by (48/80, anti-IgE, and the calcium ionophore A23,187) with IC₅₀ values of 0.1–50 M. The consistent finding relating to its mode of action was its ability to inhibit⁴⁵calcium flux into the mast cell in response to antigen or A23,187.Clinical evaluations of lodoxamide tromethamine showed that at aerosol doses of 1.0 mg or less, it demonstrated significant inhibitory activity against antigen or exercise induced bronchospasm. However, in pilot evaluation studies in clinical asthma settings, the compound could not be shown to spare bronchodilator usage, relative to placebo, or be shown to be more effective than placebo treated patients based on other clinical endpoints. The reason for rat and primate models not being predictive for human long-term clinical asthma in the characterization of anti-release compounds is not known.     

Effect of the insecticide Zectran (Mexacarbate) on several algae

Summary Field samples of freshwater algae were examined to determine the effect of the insecticide Zectran on photosynthesis rate. Concentrations of Zectran between 10 and 10³ parts per billion (ppb) affected neither O₂ production nor NaH¹⁴CO₃ uptake in any of the seven genera tested. However, Zectran at a concentration of 10⁴ ppb after 1 hour effected a reduction in photosynthesis ofChroococcus,Oedogonium and in a mixed sample composed ofZygnema,Mougeotia andSpirogyra. Mougeotia,Spirogyra andSchizogonium were not affected by exposure to 10⁴ ppb Zectran after 1 hour, but O₂ production was significantly reduced after 24 hours of exposure to this same concentration.This work was supported by an Environmental Protection Agency grant -68-01-2672.     

An autoradiographic and immunocytochemical study of the neonatal rat pituitary gland

Two-day-old female rats were injected with 5 nmole/kg of 6,7-³H-11β-methoxy-17-ethylestradiol (R 2858 = moxestrol) and killed one hour later. The animals were decapitated and, the pituitary glands were removed, mounted on tissue holders and frozen in liquified propane. The tissue was then processed for autoradiography according to the thaw mount technique. At the end of the exposure time, prior to photographic development, some of the tissue was fixed in 10% formalin and then photographically developed for autoradiography. The fixed tissue was subsequently stained immunocytochemically using antibodies to luteinizing hormone or prolactin. Between 10 and 15% of the cells of the pars distalis concentrated the synthetic estrogen or its metabolite. The immunocytochemical procedure revealed that both LH-gonadotrophs and lactotrophs concentrated the steroid. These studies along with earlier studies suggest that the neonatal rat pituitary contains only a small portion of the adult complement of estrogen receptors and that these receptors are dispersed across a number of cell types.     

Lyophilized bone allografts in periodontal intraosseous defects.

Nine patients with 10 pairs of intraosseous periodontal defects were treated. Most of the patients had identical bilateral lesions (referred to as "mirror-image" defects). In each pair, one of the defects was randomly selected and treated as a flap and currettage control whereas the other defect was grafted with freeze-dried cortical powdered allografts of bone. Evaluation was based on radiographs, photographs, and measurements taken during both the initial surgery and at reentry approximately 1 year after transplantation. Control procedures (flap and curettage) demonstrated the same amount of osseous regeneration as that seen with the graft procedure. The amount of osseous regeneration demonstrated with the grafting procedures agreed with previously published studies. Evaluation revealed that (1) an autologous control such as incorporated in the "mirrow-image" design of this study is probably the most valid experimental model available for evaluating the clinical effectiveness of any human periodontal grafting procedures; (2) the effectiveness of freeze-dried cortical powdered bone allografts in human periodontal osseous defects is questionable and needs additional study; and (3) nongrafting procedures may be more effective in generating new attachments or reattachments in human periodontal osseous defects than previously believed.