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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
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↗
PubMed1979

Calcium, phosphate, and vitamin D.

It is evident that there has been enormous progress within the last decade in our understanding of vitamin D metabolism and its interaction with calcium, phosphate, parathyroid hormone, and a number of other factors. As a result largely of therapeutic trials with various metabolites of vitamin D, we now know something of their probable involvement in the development of rickets and osteomalacia. We do not yet have a clear comprehension of exactly how these metabolites influence bone mineralization other than through their indirect effect on serum calcium and phosphate. Nonetheless it seems likely that at least one, and perhaps more, of the metabolites do exert a more direct effect. One must conclude that a deficiency of the 1alpha-hydroxylase is probably not the only defect in renal insufficiency, although it currently that there must well known. It is premature to go so far as to suggest that there must be another metabolite not being synthesized in the diseased or absent kidney.

25-Hydroxyvitamin D3 1-alpha-Hydroxylase↗
PubMed1979

Seroepidemiologic studies in Oaxaca, Mexico. II. Survey for arbovirus antibody.

A serologic survey was conducted in south-western Mexico to obtain information on human experience with arbovirus infections. Sera were collected from two semitropical areas along the Pacific coast of Oaxaca State, two mountain areas above 1,700 meters and the interior valley at 1,500 meters. Of the 610 sera tested for group A antibody, 4.9 per cent were positive in the hemagglutination-inhibition (HI) test to Venezuelan (VE), 11 per cent to Eastern, and none to Western encephalitis viruses. In neutralization tests the antibody was shown to be probably due to VE virus infections. When sera were screened for group B antibodies in the HI test, 32 per cent were positive with St. Louis encephalitis (SLE), 19 per cent with Ilhéus, and 4 per cent with yellow fever viruses. The pattern of reactions suggested that SLE or an antigenically related virus was responsible for the antibody detected. An unusually high rate was found in a mountain area at 2,000 meters: 41 per cent of 113 persons tested were seropositive to SLE. Of 493 sera screened by complement-fixation test, 6 per cent were positive to Nepuyo, 4 per cent to Patois, and 3 per cent to Tlacotalpan viruses.

Adolescent↗
PubMed1978

Chronic diarrhea in returing travelers: intestinal parasitic infection with the fluke Metagonimus yokogawai.

An unusual intestinal infection with the parasite Metagonimus yokogawai was acquired by an American traveling in the Orient. Diarrhea began abroad, and recurred at intervals until she was seen 1 1/2 years later. Stool examinations resulted in the recovery of small operculated ova characteristic of intestinal or biliary fluke infection. Treatment with hexylresorcinol failed to eradicate the infection, but subsequent use of tetrachloroethylene was successful and facilitated recovery of adult parasites, leading to the specific diagnosis of metagonimiasis. Metagonimiasis and related intestinal fluke infections should be considered as a possible cause of persistent diarrhea in travelers returning from endemic areas abroad.

Chronic Disease↗
PubMed1978

Calcium flux during hemodialysis.

A system of equations has been derived, and examined, to decribed membrane permeability and calcium fluxes within a commonly used hemodialyzer, the Mini-Kiil. By a statistical technique of sequential multiple regression analysis, factors which might influence these variables were tested on data derived from 74 hemodialysis periods in 5 patients. Calcium flux from plasma to dialysate was influenced positively by dialysate calcium concentration and plasma volume flow and negatively by dialysate volume flow. Calcium flux from dialysate to plasma was influenced positively by dialysate calcium concentration and plasma volume flow and negatively by plasma phosphate concentration. Net calcium flux from dialysate to plasma was influenced positively by the calcium gradient (dialysate calcium minus plasma ultrafiltrable calcium) and plasma volume flow and negatively by plasma phosphate concentration (coefficient of multiple correlation =0.970). Because of the magnitude of regression coefficients, manipulations of the dialysate calcium concentration and plasma phosphate concentration were concluded to be the most practical means of adjusting calcium delivery during dialysis.

Calcium↗