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Biomedical subjects

S Rabinovich

Publications and source records attributed to S Rabinovich.

At least 37 records · Page 2Linked to original sources
PubMed1983

Ultrastructure of normal rabbit mesentery.

The ultrastructure of the mesentery was examined by electron microscope (EM) after in vivo fixation in 7 normal rabbits. In 1, the fixation was performed after intravenous injection of an electron-dense tracer (iron dextran) and intraperitoneal infusion of dialysate 4.25% for 1 h. We studied morphometric data of what is considered to be the active peritoneal dialysis membrane, i.e. capillary endothelial cells, interstitium and mesothelial cells. The mesothelial cells are flattened and overlapping with tight junctions between them. They lie on a continuous basement membrane and they contain numerous intracytoplasmic vesicles, separated or in clusters. The mesenteric microvessels were mainly true capillaries of continuous type and postcapillary venules. Capillary lymphatics and larger lymphatic channels (lacunae) seem to be more extensive than the blood capillaries and venules. The endothelial cells contain many vesicles. The interstitium consists of bundles of collagen, fibroblasts and occasional macrophages. The electron-dense tracer was found in the vesicles of the mesothelial cells suggesting that vesicular transport may play an important part in the transportation of at least molecules of a certain size.

Animals↗
PubMed1983

Effect of silica on the susceptibility of mice to experimental histoplasmosis.

The role of macrophages in the innate immunity of mice to histoplasmosis was investigated using silica, which selectively inactivates macrophages. Mice given silica IV 1 day prior to challenge with live yeast cells of Histoplasma capsulatum were more susceptible to infection than were untreated controls. This increased susceptibility to Histoplasma was observed when mice were given silica at 1, 14, and 21 days prior to infection but not at 3 and 7 days. Silica treated mice that survived 30 days after challenge with a sublethal dose of Histoplasma had 23 times more viable organisms in their spleens than in those of untreated controls. The blastogenic response of spleen cells to concanavalin A and phytohemagglutinin was unaffected at 12 hr after silica injection but was significantly depressed between 1 and 21 days. In contrast, silica treatment did not affect the blastogenic response of spleen cells to lipopolysaccharide. Silica particles were cytotoxic for mouse peritoneal macrophages but not to lymphocytes in vitro. These results indicate that macrophages play an essential role in natural immunity to histoplasmosis.

Animals↗
PubMed1983

Practical procedures in internal medicine: a workshop for fourth-year medical students.

A series of workshops demonstrating technical skills and practical procedures in internal medicine was conducted for fourth-year medical students. With the chance to observe and in some situations to perform the technical procedures under supervision, the students could become familiar with these techniques before beginning their residencies. Students from 13 medical schools participated. The consensus of the students was that this aspect of their training was neglected in medical school, that the experience was very valuable, and that additional procedure-oriented opportunities were necessary.

Clinical Competence↗
PubMed1983

Avascular necrosis of bone with rheumatoid vasculitis.

A 76-year-old woman with classical rheumatoid arthritis presented with a left groin mass associated with radiologic erosion of the adjacent bony public ramus. The hip joint was not involved. Computerized tomography showed an encapsulated cyst of the pubic ramus that was surgically excised and measured about 6 x 8 cm. Histologic examination of the cystic mass and adjacent bone showed marked avascular necrosis, surrounded by an acute necrotizing vasculitis with fibrinoid necrosis. We postulate that, in this case, rheumatoid vasculitis caused an avascular necrosis of the pubic ramus.

Aged↗
PubMed1981

Treatment of renal osteodystrophy with 1,25-dihydroxycholecalciferol.

Nine patients with renal osteodystrophy were tested for 6.5 to 35 months with 1,25-dihydroxycholecalciferol (1,25-DHCC). A close biochemical follow-up was performed during the first 6 months of treatment, including biweekly determinations of serum calcium, phosphorus, magnesium, alkaline phosphatase and creatinine levels. A bone biopsy, radiologic investigations and determinations of plasma levels of immunoreactive parathyroid hormone (IPTH) and intestinal absorption of calcium 47 were performed before and after the 6 months. Although the five patients with osteitis fibrosa showed a significant improvement, the four with predominantly osteomalacic lesions showed no response to treatment. These four had a normal initial plasma iPTH level, higher serum calcium levels than the other five patients, extreme sensitivity to 1,25-DHCC, with frequent episodes of hypercalcemia, and only a slightly increased serum alkaline phosphatase level, which remained unchanged during treatment. All but one of the patients, irrespective of the histologic abnormality, showed a decrease in the uptake of radionuclide by bone after treatment. The renal function of one patient, a man with long-standing stable renal failure who had not undergone dialysis, deteriorated during treatment.

Calcitriol↗
PubMed1978

Unusual fractures associated with osteoporosis in premenopausal women.

Two premenopausal women (aged 40 and 34 years) and multiple undisplaced, often asymptomatic fractures of the femurs, ribs, metatarsals and other bones. The fractures, which appeared on roentgenograms as transverse radiolucent zones with variable callus formation, healed slowly or not at all despite treatment with calcium and vitamin D. They resembled pseudofractures (Looser's transformation zones) radiologically, but the biochemical and histologic findings were those of idiopathic osteoporosis rather than osteomalacia. Since neither patient had been subjected to unusual stress it was concluded that the fractures had resulted from normal activity in abnormal bone.

Adult↗
PubMed1978

Detection and pathogenesis of visceral calcification in dialysis patients and patients with malignant disease.

Scintiscanning to detect the uptake of bone-seeking radioactive isotopes by soft tissue is a promising technique for the in vivo study of visceral calcification. Visceral uptake of such radioisotopes was studied in 40 patients: 22 undergoing long-term dialysis, 9 with malignant disease and hypercalcemia and 9 with primary hyperparathyroidism and hypercalcemia.Fifteen patients, 11 undergoing dialysis and 4 with malignant disease, had radioisotope uptake in the lungs, and 5, 3 undergoing dialysis and 2 with malignant disease, had uptake in the stomach. None of the patients with primary hyperparathyroidism had visceral uptake, nor did the patients with uptake have radiologic evidence of pulmonary or gastric calcification. The dialysis patients with visceral uptake had a mean calcium x phosphate product of 84.3 +/- 23.7 (standard deviation), which was significantly greater (P < 0.001) than that of patients without such uptake (59.2 +/- 14.0). Similarly, in patients with malignant disease and visceral uptake the Ca x P product was 72.2 +/- 6.4 - significantly greater (P < 0.005) than that of patients without such uptake (49.3 +/- 6.7).These findings indicate that scintiscanning for the visceral uptake of a bone-seeking radioisotope is a simple and effective technique for the in vivo study of visceral calcification. An elevation in the Ca x P product seems to be the single most important factor in the production of visceral calcification.

Adult↗
PubMed1978

Visceral calcification and the CaXP product.

The authors studied the presence of visceral calcification as evidenced by the visceral uptake of bone-seeking radionuclides during the course of a bone scan among 22 patients with terminal renal failure maintained on dialysis, nine patients with hypercalcemia secondary to malignancy, and nine patients with primary hyperparathyroidism. Uptake by the lungs or stomach was observed in 11 renal failure patients (50%) and in four of those with malignancy and hypercalcemia (44%). None of the patients with primary hyperparathyroidism had evidence of visceral calcification. The serum CaXP product was significantly higher among those with visceral calcification than those without. The results of this study indicate that a CaXP product of 60 represents the saturation product of calcium phosphate in serum above which spontaneous precipitation of this salt may occur in such viscera as stomach and lungs.

Adult↗
PubMed1977

Purpura associated with hypergammaglobulinemia, renal tubular acidosis and osteomalacia.

Two patients with hyperglobulinemia associated with purpura were studied. One had features of Sjögren's syndrome, while the other appeared to have a primary condition -- "chronic benign purpura". Both patients also had renal tubular acidosis, osteomalacia and renal calculi, with disturbed calcium metabolism and acid-base balance. Autoantibodies were detected in the serum of both patients, and mononuclear cell infiltrates were noted in skin and kidney biopsies from both.

Acid-Base Equilibrium↗
PubMed1977

Partial body calcium measurements on patients with renal failure.

The bone calcium status of 39 patients with chronic renal failure on hemodialysis has been measured by in vivo neutron activation analysis (IVNAA) and reported in terms of a calcium bone index (CaBl) which relates the calcium in a patient to that in a normal person of the same height. In 20 of the 39 cases sequential measurements were made over periods of up to 40 mo. The results are compared with data obtained by radiology and by histological examination of bone biopsies. CaBl values varied from below normal to, in one case, above the range of normal. Many of the higher values were associated with demonstrable osteosclerosis. As found in previous work here with IVNAA, significantly low values of CaBl were associated with vertebral deformities; however, some patients with deformity had normal CaBl values, indicating that these had both local mineral loss (resulting in fracture) and osteosclerosis. Taken all together, the data suggest that more than half the patients have osteosclerosis. Sequential data showed no uniform response to treatment.

Adult↗
PubMed1973

5-Fluorocytosine in the treatment of experimental candidiasis in immunosuppressed mice.

A model infection with Candida albicans was established in mice. The animals were pretreated for 1 week with azathioprine, given dexamethasone, and then infected intravenously with Candida. Mortality for the group given Candida infection alone was 20%, 38% when azathioprine was added, and 50% when dexamethasone and azathioprine were given with infection. The titers of Candida in most mice were 10(6) per gram of kidney. The rest of the mice were killed at 30 days. At this time, 16% had no evidence of Candida in the kidneys, but 40% of the mice had titers of 10(6) or more. Mice treated with 5-fluorocytosine had a mortality of less than 4% in 30 days. Five percent of the treated mice killed at 30 days had titers of Candida of 10(6). Therefore, 5-fluorocytosine increases survival in the presence of continued therapy with azathioprine with or without pretreatment with dexamethasone. The survival is associated with decreased titers of Candida in the kidneys.

Animals↗