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Biomedical subjects

R S Goldsmith

Publications and source records attributed to R S Goldsmith.

At least 19 recordsLinked to original sources
PubMed1994

The development of new foci of echinococcosis in northern Israel: prevalence in domestic animals.

In a survey carried out in 1991-1992 in the town of Yirka in Northern Israel, 49 dogs were examined for Echinococcus granulosus infection and abattoir data, based on organs condemned for the presence of parasites, was collected. The presence of E. granulosus by arecoline test was demonstrated in 7 (14.2%) of the dogs examined, but not parasites were found in the intestines of five stray dogs shot in the area. A survey of sheep slaughtered in the local abattoir during a one-month period revealed Echinococcus cysts in 10% of the 255 animals examined. No Echinococcus parasites were detected in 21 dogs examined 3 months after the initiation of praziquantel treatment. Echinococcosis seems to be a very serious public health problem in Israel and a control programme needs to be given a high priority.

Abattoirs↗
PubMed1994

Detection by immunoblot assay of antibodies to Taenia solium cysticerci in sera from residents of rural communities and from epileptic patients in Bali, Indonesia.

Several studies from Bali have indicated the presence of Taenia solium. Relatively little has been reported, however, implicating human exposure to this parasite on Bali based upon the prevalence of anti-T. solium antibodies in asymptomatic and epileptic individuals. This study was conducted to determine by immunoblot assay and ELISA the frequency of anti-cysticercus antibodies in two groups of Balinese. Among 746 residents of four ecologic zones, 94 (13%) were positive by immunoblot. Of 74 epileptic patients from throughout the island, 10 (14%) were positive by immunoblot and 8 (11%) by ELISA; however, only 4 (22%) of the 18 sera positive in either test were positive in both assays. The previously defined high specificity and sensitivity of immunoblot indicates that T. solium cysticercosis is well established in Bali and that a significant amount of epilepsy may be due to neurocysticercosis.

Adolescent↗
PubMed1992

Clinical and epidemiologic studies of Chagas' disease in rural communities of Oaxaca, Mexico, and an eight-year followup: II. Chila.

A seroepidemiologic survey conducted in 1971 in the rural Pacific coastal community of Chila in the Mexican state of Oaxaca showed an unusually high prevalence of antibody against the Chagas' disease agent Trypanosoma cruzi. Further studies were undertaken in 1973 and 1981 to (1) determine the pathologic impact of T. cruzi infection in humans, (2) investigate the natural history of the disease, (3) confirm that serologically positive persons were parasitologically positive, and (4) evaluate whether T. cruzi transmission continued into the next decade. This article reports results derived from those studies.

Adolescent↗
PubMed1990

Intestinal helminthic and protozoal infections and urinary schistosomiasis in Egyptian children.

To extend information on the current distribution and frequency of parasitic infections in Egypt, one stool and one urine specimen from 2945 children, aged 6 to 12 years old were examined. The children were from 10 schools, one in Cairo, 2 in Giza Governorate, and 7 in the Nile delata. Frequency rates for S. mansoni by school were 0.3% in Cairo, 8-15% in Giza, and 3-79% in the delta; for S. haematobium, rates were 3% in Cairo, 25-71% in Giza, and 0-33% in the delta. Rates for strongyloidiasis, trichuriasis, and trichostrongliasis were low in each location never exceeding 1%. Frequency rates for ascariasis were 3-31%, ancylostomiasis 3-8%, enterobiasis 2-22%, hymenolepiasis 4-20%, amebiasis 13-52%, and giardiasis 5-25%. F. hepatica infections (0.01%) were found in Sobtas, and an 8% H. heterophyes infection rate was found in Mataryia.

Child↗
PubMed1989

Occupational exposure to hepatitis B virus in hospital personnel in Cairo, Egypt.

To identify hospital occupational categories at potential risk of hepatitis B virus infection, a serologic survey was conducted for hepatitis B surface antigen (HBsAg) and antibody (anti-HBs) by enzyme-linked immunosorbent assay in 765 employees at 4 hospitals in Cairo, Egypt. Overall, 3% HBsAg and 28% anti-HBs seromarkers. Combined HBsAg and anti-HBs frequencies by occupational group were: nonprofessional staff (60%), dentists (32%), graduate nurses (33%), physicians (29%), and student nurses (26%). The main risk factors for hepatitis B infection were frequency of exposure to patients' blood (for physicians, p less than 0.001) and to patients with jaundice (for dentists, p less than 0.01), and years of exposure to patients, as reflected by duration of occupation (for physicians, p less than 0.001) and by age of health care worker. Seropositivity by sex was greater for males (p less than 0.01). Physician specialties with highest risk of infection (29 to 53%) were surgery, infectious diseases, obstetrics-gynecology, and emergency medicine.

Adolescent↗
PubMed1988

The etiology of acute hepatitis in adults in Egypt.

The causes of acute hepatitis were prospectively studied in 141 patients admitted to Embaba Fever Hospital, Cairo, Egypt in 1983. Serologic diagnosis showed: hepatitis A (0.7%), hepatitis B (46.8%), dual infections with A and B (1.4%), acute hepatitis in HBsAg carriers (14.2%), drug induced hepatitis (5.7%), and hepatitis non-A non-B (NANB) (31.2%). Among hepatitis B patients tested for the following seromarkers, 40% had HBeAg, 8% anti-delta antibody, and 6 simultaneous presence of HBsAg and anti-HBs; in convalescence, a 9% HBsAg carrier rate was found. Clinical, epidemiological, and biochemical findings did not distinguish one cause of hepatitis from another. For 32% of NANB patients parenteral injection was a likely source of infection.

Adolescent↗
PubMed1985

Serum concentration of 1,25-dihydroxyvitamin D in the human: diurnal variation.

The serum concentrations of many hormones exhibit regular circadian rhythms. To determine if the serum concentration of 1,25-dihydroxyvitamin D [1,25-(OH)2D], undergoes periodic changes during the day, we measured the serum concentration of 1,25-(OH)2D every 30 min for 28 h in five normal men. Serum concentrations and urinary excretion rates of calcium (Ca) and inorganic phosphate (Pi) also were measured. The results indicate that the serum concentration of 1,25-(OH)2D does not undergo any large fluctuations during the day, but, rather, is maintained within approximately 20% of its overall 24-h mean. In two of five men, part of the observed daily variation could be attributed to a low amplitude (less than or equal to 10%) circadian rhythm, with the mean acrophase occurring at 1645 h. The previously reported circadian rhythms in serum concentration and urinary excretion rates of Ca and Pi were confirmed. Although the rhythmic changes in serum 1,25-(OH)2D in two subjects were not correlated with the diurnal changes in the serum concentrations of Ca or Pi, a significant negative correlation (r = 0.61; P less than 0.001) was found between the circulating concentrations of Ca and Pi.

Adult↗
PubMed1984

Use of the enzyme-linked immunosorbent assay (ELISA) for detection of Entamoeba histolytica antigen in faecal samples.

A promising new ELISA method developed by Root et al. to diagnose amoebiasis by the detection of Entamoeba histolytica coproantigen was tested in Mexico City and was reported to be more than twice as sensitive as microscopy. In this study the same procedure was compared to microscopy for paired specimens from 107 patients in San Francisco. Microscopy was more than twice as sensitive as ELISA: of 12 specimens positive by microscopy only 5 were also positive by ELISA. The ELISA did not detect a single specimen not detected by microscopy. Over-all, there was a 93% agreement between the two tests: 5% were positive and 89% negative by both tests. Possible reasons for the differences in the San Francisco and Mexican City findings are discussed.

Antigens, Protozoan↗
PubMed1984

Plasma vitamin D metabolite concentrations in chronic renal failure: effect of oral administration of 25-hydroxyvitamin D3.

The circulating concentrations of 1,25-dihydroxyvitamin D and 24,25-dihydroxyvitamin D are abnormally low in patients with chronic renal failure (CRF). To determine the importance of substrate (25-hydroxyvitamin D) concentration in this phenomenon, five patients with end stage renal disease treated with hemodialysis were given 25-hydroxyvitamin D3 (25-OH-D3) orally for 4 weeks. The serum concentration of 25-OH-D3 increased from a mean (+/- SEM) of 26 +/- 5 ng/ml immediately before therapy to a maximum of 108 +/- 5 ng/ml 4 weeks after beginning administration of 25-OH-D3. The concentrations of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3), 24,25-dihydroxyvitamin D3 (24,25(OH)2D3), and 25,26-dihydroxyvitamin D3 (25,26(OH)2D3) increased from 6.6 +/- 0.8 pg/ml, 0.29 +/- 0.10 ng/ml, and 0.36 +/- 0.06 ng/ml, respectively, immediately before 25-OH-D3 administration to 21.7 +/- 2.2 pg/ml, 0.48 +/- 0.09 ng/ml; and 0.78 +/- 0.12 ng/ml, respectively, after 4 weeks of administration of 25-OH-D3. These results suggest that substrate availability may be an important determinant of the circulating concentrations of these metabolites in patients with CRF. It seems possible that the therapeutic effects of 25-OH-D3 administration to the CRF patient may be mediated through the normal actions of 1,25-dihydroxyvitamin D3, 24,25-dihydroxyvitamin D3, and perhaps other metabolites rather than through analog effects of 25-OH-D3.

24,25-Dihydroxyvitamin D 3↗
PubMed1983

Mucosal calcium uptake by rat cecum: identity with transcellular calcium absorption.

Unidirectional intestinal calcium uptake (JCame) at the mucosal surface of rat cecum was investigated in vitro with intact tissue. Uptake is linear for 2-3 min with no indication of rapid calcium binding. Kinetic parameters reveal a maximal velocity of 333 nmol . cm-2 . h-1 with a half-maximal concentration of 0.98 mM. High-calcium diet decreased JCame by more than 60% with respect to both control and low-calcium diets; 1 mM N-ethylmaleimide caused a similar reduction. The activation energy of JCame is significantly less than that of transepithelial mucosal-to-serosal calcium absorption. Mucosal uptake was compared with transepithelial calcium fluxes in rat cecum and revealed a 1:1 correlation over a wide range of transport rates. These results are interpreted to implicate a feedback control system between basolateral calcium efflux and brush-border calcium influx.

Animals↗
PubMed1982

Hyperphosphatemic tumoral calcinosis: association with elevation of serum 1,25-dihydroxycholecalciferol concentrations.

Seven siblings with hyperphosphatemic tumoral calcinosis were studied using metabolic measures. Serum phosphorus and 1, 25-dihydroxycholecalciferol concentrations were significantly increased and serum parathyroid hormone and 25-hydroxycholecalciferol concentrations were significantly decreased in these subjects. Metabolic balance studies done in three of the siblings showed positive calcium and phosphorus balances, reflected by increased gastrointestinal absorption and decreased renal excretion. These data suggest that a hereditary abnormality of vitamin D metabolism may be present in patients with hyperphosphatemic tumoral calcinosis. Failure of the normal feedback mechanism regulating the 25-hydroxy-1-alpha-hydroxylase enzyme is suggested as the major cause. Although this defect could lead to many of the metabolic abnormalities seen in these patients, the overall contribution of altered vitamin D metabolism to the pathogenesis of tumoral calcinosis is not fully understood.

Adolescent↗
PubMed1981

Transepithelial calcium transport by rat cecum: high-efficiency absorptive site.

Transepithelial calcium transport has been investigated in rat cecum under in vitro voltage-clamp conditions. Under short-circuit conditions, the cecum behaves as a relatively tight epithelium for calcium fluxes, where mucosal-to-serosal (JCam leads to s) flux exceeds the reverse flux by at least 15-fold. JCanet is abolished in the presence of 1 mM N-ethylmaleimide, is inhibited by 40% with 1 mM ouabain, and is decreased by at least 60% when medium sodium is replaced by choline. Voltage-clamping experiments suggest that both electroneutral- and electrogenic-mediated calcium fluxes traverse the cell in the mucosal-to-serosal direction. Serosal-to-mucosal flux is purely diffusional and probably constrained to the paracellular pathway. In rats weighing less than 175 g, a low-calcium diet has no significant stimulatory effect on JCam leads to s, but a high-calcium diet markedly reduces this flux. These results suggest that the cecum possesses the highest density of calcium transport sites in the rat intestine and is ideally suited for bulk calcium absorption, which may be "down regulated" in response to an increased calcium load in growing animals.

Animals↗