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S Ott

Publications and source records attributed to S Ott.

62 records · Page 4Linked to original sources

Bone aluminum and histomorphometric features of renal osteodystrophy.

To evaluate the relationship between aluminum and the characteristics of bone disease in uremia, bone aluminum content and quantitative histomorphometric analysis of bone were evaluated in bone biopsies from 59 uremic patients undergoing maintenance hemodialysis. Biopsies were classified as showing 1) pure osteomalacia (OM) in 23 cases, 2) osteitis fibrosa (OF) in 13, 3) mixed in 7, and 4) mild lesions in 16. There were no significant differences in levels of serum calcium or alkaline phosphatase between the groups, but serum phosphorus levels were slightly higher in those with OF. Serum immunoreactive parathyroid hormone levels were greater in the patients with OF and mixed lesions than in patients with OM or mild lesions (P less than 0.01). Bone aluminum exceeded normal in all groups (P less than 0.01), with values of 175 +/- 18 mg/kg dry wt in OM patients, 46 +/- 7 of OF patients, 81 +/- 29 in mixed subjects, and 67 +/- 7 in patients with mild lesions. Bone aluminum was significantly higher in the OM patients than in any other group (P less than 0.01); also, bone aluminum correlated with the quantitative measure of unmineralized osteoid in OM (r = 0.67; P less than 0.001); no correlations existed for the other groups. There were inverse correlations between bone aluminum and the serum immunoreactive parathyroid hormone (r = -0.35; P less than 0.01) and resorbing surface on biopsy (r = -0.44; P less than 0.001). Bone aluminum correlated with the duration of hemodialysis in patients with OF with mixed and mild lesions (r = 0.49); no relation was seen in OM patients, and bone aluminum was higher for the duration of dialysis, suggesting that aluminum may accumulate more rapidly in OM subjects. These findings are consistent with but do not prove the hypothesis that aluminum plays a pathogenic role in dialysis osteomalacia; the mechanism by which aluminum accumulates remains unknown.

Aluminum↗

[Elementary diet as an alternative to parenteral feeding in severe gastrointestinal diseases].

21 patients with gastroenterological disease and indication for the use of intravenous nutrition received an elemental diet (ED) for 5-44 days. In 6 out of 8 patients with exacerbation of Crohn's disease remissions were achieved, apart from 3 persistent fistulas. In 5 out of 9 cases with various primary diseases and postoperative intestinal fistulas, spontaneous healing was observed. Furthermore, 2 patients with ulcerative colitis, 1 with radiation enteritis and 1 with pancreatitis were treated with ED. On ED, hemoglobin increased from 11.3 +/- 0.4 (m +/- SEM) to 12.0 +/- 0.5 g% (p less than 0.01) and serum albumin from 2.7 +/- 0.1 to 3.4 +/- 0.1 g% (p less than 0.001). Nitrogen requirements were studied in 11 patients receiving various quantities of ED. Nitrogen balance was found to be in equilibrium or positive in 7 patients, and negative in 4. In one patient with severe ulcerative colitis, fecal nitrogen losses were higher than urinary nitrogen losses. The unpleasant taste of ED resulting from free amino acids limited the ED supply in 3 patients and led to premature ending of ED administration in 3 other patients. In such cases ED may be given by nasogastric tube feeding. From the results presented it appears that ED is indicated in Crohn's disease and intestinal fistulas. However, the results obtained require confirmation by further observations and comparison with an intravenously fed control group.

Adolescent↗

Immunologic classification of Neisseria gonorrhoeae with micro-immunofluorescence.

A reproducible immunologic classification of Neisseria gonorrhoeae strains has been achieved by the micro-immunofluorescence (Micro-IF)3 method by using formalinized whole organisms as test antigens and mouse antisera prepared by i.v. immunization with the whole organisms as antibody. Immunologic differences among Neisseria species were also distinct in this test system. Immunologic differences among gonococcal strains were not influenced by gonococcal colony type. Classification of gonococci was facilitated by use of antisera absorbed with an antigenically unique gonococcus strain. Of 180 gonococcal strains, 175 could be classified into three immunotypes: A, B, and C. Each type was further divided into subtypes designated A1, A2, A3, B1, B2, B3, C1, and C2. Minor antigenic differences still exist within each subtype. The two gonococcal isolates from each of 17 pairs of sexual contacts fell into the same subtype. Seventy-one of 73 isolates which required arginine, hypoxanthine, and uracil for growth (Arg-Hyx-Ura-) and seven of 107 other auxotypes belonged to subtypes A2 and A3. Marked geographical differences in distribution of gonococcal immunotypes were observed among those available for testing. Subtypes A2 and A3 were predominant in Seattle whereas types B and C were predominant in Southeast Asia. The only Arg-Hyx-Ura- isolates not belonging to subtypes A2 or A3 were the only two that were serum sensitive. This Micro-IF immunotyping appears potentially useful for future immunologic, epidemiologic, and genetic studies of N. gonorrhoeae.

Asia, Southeastern↗

[Long-term results of fasting. Results from 132 consecutive patients after 1-6 1/2 years].

132 consecutive patients were reexamined 1-6.5 years (m = 2.8) after total fasting in hospital. 37 patients had continued to lose weight, 20 patients had maintained their fasting result (+/-2 kg) and 7 patients had slightly regained (less than 1/3 of their weight loss during fast). These 3 groups, totalling 64 patients (48%), were considered successful. Their mean overweight was diminished from 57 to 29%, corresponding to a 60% reduction of mortality in certain age groups. On the other hand, 63 patients (48%) had regained more than 1/3 of their original weight loss. Five patients (4%) were lost to follow-up. Selection of patients and long-term follow-up appeared to have a decisive bearing on long-term results of fasting, whereas factors such as age, sex, degree of overweight, onset of overweight in childhood and sports were without significant effect. From the long-term results presented, it is concluded that under certain conditions fasting in hospital is warranted. Behaviour therapy is a possible alternative in the treatment of obesity.

Adolescent↗

Temperature-dependent kinetics of the activities of influenza virus.

The temperature dependence of membrane interactions between PR8 influenza virus and virus receptor (GD1a)-containing liposomes was studied. For quantitation, the octadecylrhodamine B chloride (R18) membrane marker was incorporated into liposomes at quenched concentrations. Upon interaction with target membranes, the marker gets diluted, and dequenching can be measured in a fluorescence spectrophotometer. Rate constants were calculated from the dequenching curves under low pH conditions, which allow for fusion, and at neutral pH, where no specific fusion occurs. Activation energies were determined from Arrhenius plots. The results were compared with the temperature dependence of other viral activities like infectivity, hemolysis, and fusion with erythrocytes. For the slow reaction at pH 7.4, where only non-specific lipid transfer takes place, the activation energy was about 24 kcal/mole between 15 degrees C and 45 degrees C. For the fast, hemagglutinin (HA)-specific fusion reaction (pH 5.3), a very low activation energy (approximately 7 kcal/mole) was found between 25 degrees C and 37 degrees C, whereas below 25 degrees C it was much higher (approximately 34 kcal/mole). The temperature range with low activation energy coincides with the one for optimal infectivity, hemolysis, and fusion with erythrocytes. Furthermore, it is the same range in which the conformational change of HA takes place, which in the absence of a partner membrane leads to an irreversible inactivation of the fusion protein.

Animals↗

A preliminary study of joint surface changes after an intraarticular fracture: a sheep model of a tibia fracture with weight bearing after internal fixation.

OBJECTIVE: To evaluate the changes in the articular cartilage and subchondral bone after an osteotomy designed to simulate an articular fracture. DESIGN: The contribution of the cartilage and subchondral bone was evaluated twelve weeks after creating a 1.0-millimeter step-off in the medial plateau of the tibia of twelve adult domestic sheep. All animals surviving were labeled with fluorescent markers for bone production, oxytetracycline (fifty milligrams per kilogram), and calcein (twelve milligrams per kilogram) nine and 11.5 weeks after surgery. The knees were loaded in compression using an Instron materials tester with pressure-sensitive film to record joint contact pressures above and below the medial meniscus. SETTING: The studies were performed in the research laboratories of the Orthopaedic Laboratory at Harborview Medical Center in Seattle, Washington and the Madigan Army Medical Center in Tacoma, Washington. ANIMALS: Twelve adult domestic sheep. INTERVENTION: An intraarticular osteotomy of the medial tibial plateau with 1.0 millimeter of displacement was performed. The osteotomy was stabilized with 3.5-millimeter lag screws. MAIN OUTCOME MEASURES: The contact pressures of the knee joint and articular histology were evaluated twelve weeks after surgery. Samples of the articular cartilage were analyzed by light microscopy and electron microscopy to evaluate the response of the articular cartilage and subchondral bone of the differential joint loading because of the irregularity in the articular surface caused by the osteotomy. RESULTS: The knees with an intraarticular step-off had two major contact areas with an intervening zone of reduced load corresponding to the edge of the depressed fragment. Coronal histologic sections through the articular surface showed the presence of thinning and fibrillation on the high side of the step-off and some compensatory hypertrophy of the cartilage. The subchondral bone was not responsible for restoring articular congruity because the rate of bone production was similar between the low side of the articular fracture (1.85 micrometers per day) and the high side of the fracture (1.67 micrometers per day). Scanning electron microscopy showed partial cartilage remodeling by deformation of the high side cartilage with bending of the vertical collagen fibrils, even in the unloaded state. CONCLUSIONS: In this model with a small fracture displacement (1.0 millimeter), which was less than the thickness of the articular cartilage (1.5 millimeters), the contour of the joint improved despite residual articular surface incongruency after the fracture healing.

Animals↗