Biomedical subjects

J S Reif

Publications and source records attributed to J S Reif.

At least 37 records · Page 2Linked to original sources

PubMed1993

Risk factors for exposure to arsenic at a hazardous waste site.

Communities surrounding the Rocky Mountain Arsenal (RMA), a Superfund site in Colorado, were studied in order to determine whether exposures to arsenic were greater among persons who resided there than among residents of a comparison area. A census was conducted in areas adjacent to the RMA and in a comparison area 12-15 miles distant. From a stratified random sample, 469 persons were interviewed and urine samples obtained. Arsenic was detected in urine from 43 (9.2%) of the 469 persons sampled at a detection limit of 10 ppb. Trace levels of arsenic (detectable, but non-quantifiable) were found in 184 (39.2%) of those persons sampled. Neither the frequency of detection, the arithmetic mean nor the geometric mean values for urine arsenic was found to be statistically different when persons living near the site were compared to persons from the more distant comparison area. Therefore, the data were pooled across the study areas to evaluate risk factors for exposure to arsenic in this population-based sample. Multivariate logistic regression analyses were conducted to evaluate the risk of arsenic exposure associated with variables included in the interviews while controlling for confounding. Pathways for exposure to arsenic were evaluated through analysis of residence history, occupation, hobbies, dietary habits, water supply, housing and activity patterns. Children of Hispanic origin or non-white race, children who drank less than three glasses of water daily, and children who spent more time outdoors had an increased risk of having > or = 10 ppb of arsenic in their urine. Among adults, younger persons, especially those less than 40 years of age, persons of Hispanic origin or nonwhite race, and those employed in occupations where arsenic is likely to be found had an increased risk of having > or = 10 ppb of urine arsenic. Consumption of red wine or fish during the week prior to sampling was associated with trace levels of arsenic in urine.

Adolescent↗

PubMed1992

Serologic prevalence of selected infectious diseases in cats with uveitis.

Serologic evidence of infection by Toxoplasma gondii, feline leukemia virus, feline coronaviruses, or feline immunodeficiency virus (FIV) is commonly found in cats with uveitis. Serum samples from 124 cats with uveitis were assayed by use of ELISA for the detection of T gondii-specific immunoglobulin M (IgM), IgG, and circulating antigens (Ag), as well as an ELISA for feline leukemia virus Ag, an ELISA for antibodies to FIV, and an indirect fluorescent antibody assay for antibodies to feline coronaviruses. Serologic evidence of infection by 1 or more of the infectious agents was detected in 83.1% of the samples. Serologic evidence of T gondii infection, defined as the detection of T gondii-specific IgM, IgG, or Ag in serum, was found in 74.2% of the samples. The seroprevalence of T gondii infection was significantly greater in cats with uveitis than in healthy cats from a similar geographic area. Serum samples from cats with serologic evidence of both T gondii and FIV infections were more likely to contain T gondii-specific IgM without IgG than samples from cats with serologic evidence of T gondii infection alone. Cats with serologic evidence of FIV and T gondii coinfection had a higher T gondii-specific IgM titer geometric mean and a lower T gondii-specific IgG titer geometric mean than did cats with serologic evidence of T gondii infection alone. Serologic evaluation for T gondii infection should include assays that detect IgM, IgG, and Ag, particularly in cats coinfected with FIV.

Animals↗

PubMed1992

Enzyme-linked immunosorbent assays for the detection of Toxoplasma gondii-specific antibodies and antigens in the aqueous humor of cats.

Serum and aqueous humor samples, collected from 14 clinically normal cats and 96 cats with clinical evidence of intraocular inflammation, were assayed with ELISA for Toxoplasma gondii-specific immunoglobulin M (IgM), T gondii-specific IgG, T gondii-specific antigens, total IgG, and total IgM. Additionally, serum was assayed with ELISA for feline leukemia virus p27 antigen and antibodies against the feline immunodeficiency virus as well as with an immunofluorescent antibody assay for antibodies against feline coronaviruses. Calculation of the Goldmann-Witmer coefficient (C-value) for the T gondii-specific antibodies detected in aqueous humor established the likelihood of local antibody production. Serologic evidence of present or prior infection by an infectious agent was found in 81.9% of the clinically affected cats from which serologic results were available (77/94 cats). Seropositive results for toxoplasmosis were found in 74.0% of the clinically affected cats. Anterior segment inflammation was found in 93.1% (81/87 cats from which information was available) of the clinically affected cats, most of which were older males. Toxoplasma gondii-specific antibodies were not detected in the aqueous humor of 6 seropositive, clinically normal cats. The C-values for aqueous T gondii antibodies were greater than 1 in 44.8% of the cats and greater than 8 in 24.0% of the cats. Response to treatment with clindamycin HCl was positive in 15/20 (75%) of the T gondii-seropositive, clinically affected cats treated with this drug. In 13/15 (86.7%) T gondii-seropositive, clinically affected cats having a C-value greater than 1, response to treatment with clindamycin HCl was positive.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1992

Passive smoking and canine lung cancer risk.

A case-control study was conducted to determine whether household exposure to environmental tobacco smoke is associated with an increased risk for lung cancer in pet dogs. Lung cancer cases and controls with other forms of cancer were obtained from two veterinary teaching hospitals during 1985-1987. Exposures assessed included the number of smokers in the household, the amount smoked, and the proportion of time spent indoors by the pet. A weak relation was found for exposure to a smoker in the home (odds ratio = 1.6, 95% confidence interval 0.7-3.7), after controlling for confounding in stratified analyses. Strong evidence for a further increase in risk associated with more than one smoker in the home was not found, nor was a significant trend observed for increasing number of packs of cigarettes smoked per day or an exposure index based on number of smokers in each household, packs smoked per day, and the proportion of time the dog spent within the home. However, skull shape appeared to exert effect modification; the risk was restricted to breeds with short and medium length noses (odds ratio = 2.4, 95% confidence interval 0.7-7.8). Despite the inconclusive findings of the current study, epidemiologic studies in pet animals may add to our understanding of environmental tobacco smoke effects in human populations.

Animals↗

PubMed1991

Low concentrations of primaquine inhibit degradation but not receptor-mediated endocytosis of asialoorosomucoid by HepG2 cells.

Asialoorosomucoid (ASOR) is internalized and degraded by HepG2 cells after binding to the asialoglycoprotein (ASGP) receptor, internalization through the coated pit/coated vesicle pathway, and trafficking to lysosomes. Primaquine, an 8-aminoquinoline antimalarial compound, inhibits ASOR degradation at concentrations greater than 0.2 mM by neutralizing intracellular acid compartments. This leads to alterations in surface receptor number, receptor-ligand dissociation, and receptor recycling. We have investigated the effects of primaquine on 125I-ASOR uptake and degradation as a function of primaquine concentration and duration of exposure. Concentrations below those required for neutralization of acidic compartments block 125I-ASOR degradation in HepG2 cells and lead to intracellular ligand accumulation. This effect is maximal at 80 microM primaquine. The intracellular 125I-ASOR is undegraded, dissociated from the ASGP receptor, and contained within vesicular compartments distinct from lysosomes, plasma membrane, or endosomes. In addition, the effect of 80 microM primaquine on 125I-ASOR degradation is very slowly reversible (greater than 6 h), in contrast to primaquine's rapidly reversible effect on receptor recycling and ligand uptake (10 min). Furthermore, the effect is ligand-specific. 125I-asialofetuin, another ASGP receptor ligand, is internalized and degraded in lysosomes at normal rates in HepG2 cells exposed to 80 microM primaquine. These findings indicate that primaquine has multiple effects on the uptake and degradation of ligand occurring in the endosome-lysosome pathway. These effects of primaquine differ in their concentration-dependence, site of action, reversibility, and ligand selectivity.

Asialoglycoprotein Receptor↗

PubMed1991

Multivariable prediction model for the need for surgery in horses with colic.

A survey of 1,965 equine colic cases was conducted from August 1985 to July 1986 at 10 equine referral centers located throughout the United States. The purpose of this study was to develop and validate a multivariable model for the need for surgery. Two-thirds of the cases were randomly selected for model development (1,336), whereas the remaining cases (629) were used only for subsequent validation of the model. If a lesion requiring surgical correction was found at either surgery or necropsy, the case for the horse was classified as surgical, otherwise the case was classified as medical. Only variables that were significant (P less than 0.05) in an initial bivariable screening procedure were considered in the model development. Because of the large number of missing values in the data set, only variables for which there were less than 400 missing values were considered in the multivariable analysis. A multivariable logistic regression model was constructed by use of a stepwise algorithm. The model used 640 cases and included variables: rectal findings, signs of abdominal pain, peripheral pulse strength, and abdominal sounds. The likelihood ratio for surgery was calculated for each horse in the validation data set, using the logistic regression equation. Using Bayes theorem, the posttest probability was calculated, using the likelihood ratio as the test odds and the prevalence of surgery cases (at each institution) as an estimate of the pretest odds. A Hosmer-Lemeshow goodness-of-fit chi 2 statistic indicated that the model fit the validation data set poorly, as demonstrated by the large chi 2 value of 26.7 (P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1990

Epidemiologic studies of cancer in agricultural workers.

The incidence of cancer in agricultural workers is generally low, in part due to the low prevalence of cigarette smoking in this group. However, agricultural workers have elevated risks for several specific cancer types including leukemia, Hodgkin's disease, non-Hodgkin's lymphoma, multiple myeloma, and cancers of the lip, stomach, prostate, brain, and connective tissue. Two major groups of risk factors have been proposed as causes of hematologic malignancies in agricultural workers. The first group includes various agricultural chemicals. In particular, several studies have found increased risks of malignant lymphoma and soft tissue sarcoma in persons exposed to phenoxy herbicides. However, the evidence is inconsistent and there is a wide variation in relative risk estimates. The second group of risk factors includes various animal viruses. There is currently little evidence concerning the zoonotic nature or human carcinogenicity of these viruses. However, leads have been suggested by recent evidence of increased risks of hematologic malignancies in abattoir workers, veterinarians, and meat inspectors. A third hypothesis, for which little evidence is currently available, is that agricultural work may involve prolonged antigenic stimulus leading to lymphoproliferation. The factors responsible for the increased risks for cancers other than hematologic malignancies are not well understood but may also involve exposure to chemicals or viruses.

Abattoirs↗

PubMed1990

Chlorinated hydrocarbon insecticides in Colorado beef cattle serum--a pilot environmental monitoring system.

A pilot project was initiated to test an existing animal disease surveillance system for use in monitoring environmental pollutants. Eleven chlorinated hydrocarbon insecticides were assayed to provide an indication of environmental contamination. A total of 241 bovine serum samples from 53 Colorado beef ranches was tested; 123 samples (51%) were found to contain detectable concentrations of 1 or more of 11 chlorinated hydrocarbons. There were a total of 203 occurrences of a compound being found at a level exceeding the detection limit. Heptachlor, heptachlor epoxide, lindane, and oxychlordane were the insecticides detected most frequently in bovine sera. This pilot study supports the use of domestic food-producing animals as sentinels of environmental contamination with insecticides.

Animals↗

PubMed1990

An analysis of occupational risks for brain cancer.

We evaluated the risks of brain cancer in relation to employment history in a case-control study of 312 cases and 1,248 cancer controls. Subjects were identified through the Missouri Cancer Registry for the period 1984 through 1988. Job classification was based on data routinely abstracted from hospital records. Elevated risks were identified for certain white collar occupations: for men employed in engineering, the odds ratio (OR) = 2.1; 95% confidence interval (CI) = 0.4, 10.3; for social science professionals, the OR = 6.1; 95% CI = 1.5, 26.1. Among occupations with potential exposure to occupational carcinogens, increased risks were observed for men employed in agricultural crop production (OR = 1.5; 95% CI = 1.0, 2.4), printing and publishing (OR = 2.8; 95% CI = 1.0, 8.3), and brickmasons and tilesetters (OR = 2.5; 95% CI = 0.5, 11.5). Most of elevated brain cancer risks were due to astrocytic cancers, but the excess among agricultural workers occurred in other cell types. No increase in risk was noted for current cigarette smokers (OR = 0.9; 95% CI = 0.7, 1.5) or ex-smokers (OR = 1.0; 95% CI = 0.7, 1.5). This exploratory study indicates a need for further studies of occupational risks of brain cancer.

Astrocytoma↗

PubMed1989

Cancer risks among Missouri farmers.

A series of case-control studies was conducted to investigate cancer risks among farmers. These studies were based on Missouri Cancer Registry data for 15,000 white male patients, including 1720 subjects classified as farmers, registered between 1984 and 1988. For each cancer site, all other cancer registrations formed the control group. The largest risks among farmers were found for lip cancer (odds ratio [OR], 3.07; 95% confidence interval [CI], 1.99 to 4.73) and cancer of the bone (OR, 2.02; 95% CI, 0.66 to 5.81). Elevated risks were observed for several other sites, including the nasal cavity and sinuses (OR, 1.66; 95% CI, 0.54 to 4.70), prostate (OR, 1.33; 95% CI, 1.18 to 1.51), non-Hodgkin's lymphoma (OR, 1.40; 95% CI, 1.04 to 1.85), and multiple myeloma (OR, 1.40; 95% CI, 0.87 to 2.24). Other smaller elevations in risk were noticed for cancer of the rectum (OR, 1.21; 95% CI, 0.95 to 1.53), liver (OR, 1.19; 95% CI, 0.58 to 2.37), malignant melanoma (OR, 1.26; 95% CI, 0.63 to 2.45), kidney (OR, 1.21; 95% CI, 0.89 to 1.65), and leukemia (OR, 1.12; 95% CI, 0.81 to 1.55); however, some of these estimates were imprecise due to small numbers. The overall OR for lymphatic and hematopoietic cancers was 1.28 (95% CI, 1.06 to 1.56). Consistent with previous studies, a decreased risk of lung cancer was observed among farmers (OR, 0.67; 95% CI, 0.60 to 0.76). The current findings are presented in the context of other recent studies, including discussions of possible causes of farming-associated excess cancer risk and possible sources of bias.

Adult↗

PubMed1989

Chronic exposure of sheep to a zinc smelter in Peru.

Liver levels of arsenic, cadmium, copper, lead, manganese, and zinc were assessed in adult female sheep living in the vicinity of a zinc smelter in Peru. The study was conducted on a large sheep-raising cooperative divided into seven management units, operated under a standardized husbandry system. Soil samples were analyzed for the same metals at varying distances from the smelter. A gradient of concentration of heavy metals in soil was found between 1 and 56 km from the smelter. Soil concentrations for all metals except manganese decreased significantly with increasing distance from the smelter. The strongest correlations were found for copper, lead, and zinc (P less than 0.001). Topographic features and prevailing wind direction appeared to play a role in the dispersion of pollutants. Liver samples were obtained from 153 sheep on five units of the cooperative. The centers of the units sampled were between 13 and 56 km from the smelter. Hepatic concentrations of arsenic, lead, manganese, and zinc decreased significantly with increasing distance from the smelter. Liver arsenic and liver zinc were significantly related to soil concentrations. Liver levels of arsenic, cadmium, lead, and manganese in sheep from the cooperative were significantly higher than those detected in control sheep from southern Peru. Sheep populations may serve as biological monitors for heavy metal accumulation and environmental carcinogenesis.

Animals↗

PubMed1989

Epidemiologic study of insecticide exposures, obesity, and risk of bladder cancer in household dogs.

A case-control study of household dogs was conducted to determine if exposure to sidestream cigarette smoke and chemicals in the home, use of topical insecticides, and obesity are associated with the occurrence of bladder cancer. Information was obtained by interview from owners of 59 dogs with transitional-cell carcinoma of the bladder and 71 age- and breed size-matched control dogs with other chronic diseases or neoplasms. Bladder cancer risk was unrelated to sidestream cigarette smoke and household chemical exposures. Risk was significantly increased by topical insecticide use (OR = 1.6 for 1-2 applications per year and OR = 3.5 for greater than 2 applications per year; chi 2 trend; p = .008). This risk was enhanced in overweight or obese dogs. Further studies of this canine model may facilitate identification of specific carcinogens present in insecticides commonly used on pet animals and in the environment.

Administration, Cutaneous↗

PubMed1989

Occupational risks for brain cancer: a New Zealand Cancer Registry-based study.

Occupational risks for brain cancer were evaluated in a New Zealand Cancer Registry-based case-control study. The case subjects were 452 men aged 20 years or older registered under classifications 191 (Cancer of the brain) and 192 (Cancer of other and unspecified parts of the nervous system) of the International Classification of Disease (9th ed) from 1980 to 1984 for whom occupational information was available. The remaining 19,452 men with other cancers registered during an excess of professional and technical workers. An increased risk among workers in agriculture, forestry, and fishing was due to an excess of brain cancer in farmers, with the highest risk found for livestock farmers. Although many comparisons have been made, some of the findings support previous studies and several new hypotheses are suggested.

Adult↗

PubMed1989

Human cryptosporidiosis associated with an epizootic in calves.

An outbreak of human cryptosporidiosis occurred among previously healthy persons in a veterinary medical teaching hospital. Human illness began after admission of calves from a farm which had been experiencing an epizootic of neonatal diarrhea due to Cryptosporidium. The clinical syndrome in humans was characterized by watery diarrhea, abdominal cramping, flatulence, and headache. Cryptosporidiosis was confirmed by zinc sulfate flotation of fecal specimens in four persons, three of whom had been responsible for the care and treatment of infected calves. A fourth patient had washed her husband's soiled clothing and appeared to have been infected indirectly through fomite contamination. Among 112 persons surveyed, 26 (23.2 percent) had a diarrheal illness during the outbreak and nine met the case definition of a diarrheal illness lasting at least three days. These persons were more likely to have had contact with a calf with diarrhea than were 52 referents who did not become ill during the outbreak.

Adult↗

PubMed1989

Cancer risks among New Zealand meat workers.

The study reports a series of case-referent studies based on the New Zealand Cancer Register and involving 19,904 male cancer patients aged 20 years or more at the time of registration during the period 1980-1984. For each cancer site, the registrations for the remaining sites formed the reference group. An increased risk for lung (OR 1.30, 95% CI 1.06-1.58) and laryngeal (OR 2.01, 95% CI 1.19-3.39) cancer was found among meatworkers. It was confined to men aged less than 65 years at registration. The risk for soft-tissue sarcoma was elevated (OR 1.90, 95% CI 0.90-4.02). The risk estimate for all types of leukemia was elevated moderately (OR 1.45, 95% CI 0.90-2.31), but cell type-specific analyses revealed a greater effect for acute myeloid leukemia (OR 2.12, 95% CI 1.09-4.12). This study adds to the evidence that employment as a meatworker is associated with increased risk for several forms of cancer.

Abattoirs↗

PubMed1988

Rates of diseases and their associated costs in two Colorado sheep feedlots (1985-1986).

Data related to rates of disease and their associated costs were collected for 12 months from 2 sheep feedlots in northern Colorado. There was an apparent seasonal occurrence of many of the diseases. Pneumonia, enterotoxemia, acidosis, and transport tetany accounted for most of the diseases seen in these feedlots and were responsible for most of the economic losses. There was a large difference in the incidence of diseases between the 2 feedlots and in the expenditures for disease prevention between the 2 feedlots.

Acidosis↗

PubMed1988

Validation of disease diagnoses reported to the National Animal Health Monitoring System from a large Colorado beef feedlot.

Clinical observation and collection of biological specimens from a large beef feedlot (approximately 30,0000 animals) were used to evaluate 6 approaches for validation of a disease reporting system. Data collected during a 12-month period were used to evaluate each approach. A subsample of disease cases reported to the National Animal Health Monitoring System (NAHMS) was compared with the clinical observations of the investigators. Although the agreement between clinical diagnosis by the NAHMS veterinarian and by feedlot health crews was high, the sensitivity and specificity of specific diagnoses varied from 100 to 18% and from 99 to 76%, respectively, which suggests that regular clinical observations by a veterinarian are needed to validate disease diagnoses reported to NAHMS by producers. Subsampling of a group of cattle by means of paired serologic determination of antibodies to infectious bovine rhinotracheitis virus, bovine viral diarrhea virus, bovine respiratory syncytial virus, and parainfluenza-3 virus revealed a high serologic conversion rate to infectious bovine rhinotracheitis, and high levels of preexisting antibody to bovine respiratory syncytial and parainfluenza-3 viruses. It was concluded that the current method of data collection for Colorado feedlots provides an acceptable level of sensitivity and specificity for the program. However, disease events that are not of economic importance to the feedlot operator will be underestimated. If an objective of NAHMS is to develop a base line of animal health conditions, diagnosis of diseases by current methods will be satisfactory. Occasional validation through clinical observations by a veterinarian will suffice to monitor quality of collected data.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1988

Increased risks of soft tissue sarcoma, malignant lymphoma, and acute myeloid leukemia in abattoir workers.

This paper presents a review and further analysis of a series of New Zealand case-control studies which have found elevated risks for soft tissue sarcoma (STS), non-Hodgkin's lymphoma (NHL), and acute myeloid leukemia (AML) in abattoir workers. The first published study involved 82 cases of STS (ICD 171) and found a relative risk of 2.8 (90% confidence interval 1.3-6.3). Interviews with an additional 51 cases reported here revealed a relative risk of 1.6 (90% confidence interval 0.9-3.0). Two further studies involved interviews with 100 cases of the category of NHL involving lymphosarcoma and reticulosarcoma (ICD 200) and 83 cases of other NHL (ICD 202). Relative risk estimates were 1.8 (90% confidence interval 1.1-2.9) and 1.7 (90% confidence interval 1.0-2.8), respectively. A study of 150 cases of AML (ICD 205.0) found a relative risk of 2.5 for abattoir workers (90% confidence interval 1.3-4.7). Finally, a United States cohort study found a standardized mortality ratio of 2.4 (90% confidence interval 0.8-5.4) for Hodgkin's disease (ICD 201) and 2.2 (90% confidence interval 0.8-4.5) for cancer of other lymphatic tissue (ICD 202, 203, 208) among abattoir workers. Abattoir workers are potentially exposed to oncogenic viruses, including bovine leukemia virus. Some workers may also be exposed to the animal carcinogen 2,4,6-trichlorophenol when treating pelts.

Abattoirs↗