Biomedical subjects
Publications and source records attributed to D Kaplan.
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The cases of two patients with acute necrotizing ulcerative infections are reported. One had involvement of the tonsil and the other, of the gingivae. In both cases a Gram stain revealed abundant fusiform rods and spirochetes. Both patients responded to treatment with oral penicillin, showing improvement and/or healing in three to six days. These two cases demonstrate the usefulness of the Gram stain in supporting a diagnosis which would otherwise rest solely on clinical grounds.
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We have measured high-resolution x-ray absorption spectra of lanthanide (Ln) and heavy transition metal complexes that display prominent narrow absorption peaks near the L2 and L3 absorption edges. The anomalous scattering factors (f' and f"), which are mathematically related to the absorption cross section, have correspondingly sharp changes in their magnitude within 5-10 eV of the absorption edge. Calculations of the magnitude of the change in f' and f" demonstrate that significant changes (on the order of 20 electrons in f') can be expected for these materials. These substantial changes in the anomalous scattering factors have applications to deriving structural information for macromolecules from x-ray diffraction studies. The magnitude of the changes indicate that the anomalous scattering technique is a powerful means of obtaining structural characteristics for macromolecules in single crystals, in solution, and in biological membranes.
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In a prospective study of 226 patients with systemic lupus erythematosus (SLE), 91 patients (40%) had Raynaud's phenomenon. These patients were compared to 135 patients without Raynaud's phenomenon. Patients with Raynaud's phenomenon had a greater incidence of arthritis (P less than 0.02), malar rash (P less than 0.003), and photosensitivity (P less than 0.03), and a lesser incidence of severe renal disease as manifested by serum creatinine over 3.0 mg/dl (P less than 0.007) or creatinine clearance below 60 ml/minute. Patients with Raynaud's phenomenon were less likely to have severe, life threatening disease and received a lower average monthly (P less than 0.01) and a lower peak daily corticosteroid dose (P less than 0.01). Fourteen patients (16%) with Raynaud's phenomenon died, compared to 41 without (30%) (P less than 0.03). Raynaud's phenomenon in patients with SLE is associated with milder disease and may be regarded as a favorable prognostic sign.
A computer analysis was made of the data from a prospective study of the clinical course of systemic lupus erythematosus (SLE) in 234 patients followed for an average of 46 months. All fulfilled four ARA criteria for the diagnosis of SLE. Sixteen of the 234 patients were aged 51 or older. They were compared with the 218 younger SLE patients to determine the influence of age on the signs and symptoms of the disease, the organ systems involved, the laboratory data, amount and duration of corticosteroid or azathioprine therapy, and the prognosis. The older group showed more discoid lupus, photosensitivity and pulmonary fibrosis than did the younger group, but a similar incidence of malar rash, alopecia, arthritis, arthralgia, myalgia and serositis, and a lower incidence of oral ulcers, Raynaud's phenomenon, cutaneous vasculitis, neuropsychiatric manifestations, leukopenia, hypocomplementemia and profus proteinuria. The older patients needed a lower dosage of corticosteroids, and a shorter course of azathioprine therapy. These findings suggest a milder form of SLE with better response to therapy in the older group.
Minimum bactericidal concentrations of salicylate, nicotinaldehyde singly, and in combination with nicotinic acid, or nicotinamide were determined for Staphylococcus aureus 79 and 80, and Escherichia coli 95, at inocula of 10(7)--10(2). The bactericidal dose of salicylate was affected markedly by the inoculum size. The bactericidal dose of nicotinic acid, or nicotinamide was affected only slightly by the size of the inoculum. Escherichia coli 95 was least affected by the inoculum size. Nicotinaldehyde is a far more bactericidal agent than is nicotinic acid, or nicotinamide; its bactericidal dose was approximately a tenth that of nicotinic acid, or nicotinamide. S. aureus 79 and 80 were affected synergistically by the combinations of nicotinic acid, or nicotinamide with salicylate. Nicotinaldehyde reduced the effectiveness of nicotinic acid, at all inoculum sizes, of S. aureus 79, while the reduction of effectiveness of nicotinamide was only found with inocula of 10(7)--10(5). At low inocula, 10(4)--10(2), an additive effect was demonstrated. S. aureus 80 was antagonistically affected, at all inoculum sizes, by the combination of nicotinaldehyde with nicotinamide, while with nicotinic acid a slight synergy was noted. In contrast, Escherichia coli 95 was antagonistically affected, at all inoculum sizes, by combinations of nicotinic acid, nicotinamide with salicylate, or nicotinaldehyde.
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Although telephone calls comprise almost one fourth of all childhood patient-physician contacts, the content of telephone care is not emphasized in most educational and service programs. In response to the need to improve management of telephone calls to our pediatric emergency room, we developed 28 protocols to deal with the 25 most common complaints presented by phone. This paper describes the content of these protocols, the training of the health assistants who administered them, and the measures we took to assure their safety and general utility in pediatric practice settings. The study demonstrates the feasibility of an organized system for telephone care based on protocols which include: (1) basic data to be collected for each chief complaint category; (2) a range of appropriate dispositions; and (3) advice for home management when the patient does not require an immediate medical visit. Potential uses of these protocols for medical and nursing education and for clinical service needs are discussed.
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The necessity of studying on an animal model the effects of the space environment on the major physiological functions has led the Centre de Recherches de Medecine Aeronautique to develop a two-primate experiment biological facility for SPACELAB. The general principle followed throughout all the phases of this project is that the facility is designed to be used, not for one specific experiment, but by the largest possible number of researchers. We describe here the justification for a primate animal model, the technological features of the biological module and several experiments designed to test certain hypotheses with regard to physiology and pathology.
The deoxyribonucleic acid (DNA)-degrading potential of metronidazole was evaluated in vitro by three techniques: determination of melting curve, measurement of viscosity, and centrifugation in neutral or alkaline sucrose gradients. Studies were performed on calf thymus DNA and on (3)H-labeled or unlabeled pneumococcal and T7 phage DNA after treatment with metronidazole alone or metronidazole reduced by sodium dithionite in the presence of DNA. This latter process is known to elicit covalent binding of metronidazole to DNA. Reduced or unreduced metronidazole had no effect on the melting properties, viscosity, or sedimentation velocity of the nucleic acids studied. Sodium dithionite alone, however, caused a 25% decrease in the intrinsic viscosity of pneumococcal DNA, and decreased the sedimentation velocity of pneumococcal and T7 phage DNA in both neutral and alkaline sucrose gradients. These data suggest that degradation of DNA is not important in the interaction of metronidazole with nucleic acids, an interaction assumed relevant to the cytotoxic, radiosensitizing, and mutagenic activities of this compound.
SLE is an illness of unknown cause(s) affecting multiple organ systems, whose diagnosis depends upon a high index of suspicion and knowledge of its clinical manifestations. The American Rheumatism Association criteria may be used as a guide to help direct one's clinical and laboratory approaches. Survivorship appears to be improving and a wider spectrum of disease is appreciated today.
A computer analysis of 234 patients with SLE followed for an average of 31 months revealed 22 patients with aseptic necrosis of bone (AN) (9%), with projected frequency approaching 30% at 10-15 years of follow-up. Most patients developed between four and seven years after diagnosis of SLE. When compared to all other patients with SLE and no AN or to three computer-selected groups matched by age of SLE diagnosis, duration of disease, or cumulative corticosteroid dose, AN did not correlate with any of the preliminary ARA criteria, total number of criteria fulfilled, renal disease, skin vasculitis, or disease activity. Although all patients received corticosteroid therapy prior to development of AN, no correlation was found with duration, peak dose, or cumulative dose of corticosteroid therapy.
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