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Biomedical subjects

H A Anderson

Publications and source records attributed to H A Anderson.

At least 37 records · Page 2Linked to original sources
PubMed1999

Serum PCB and DDE levels of frequent Great Lakes sport fish consumers-a first look. The Great Lakes Consortium.

Great Lakes (GL) sport fish consumption is a potential human exposure route for polychlorinated biphenyls (PCBs) and dichlorodiphenyl dichloroethene (DDE). Because of fish tissue contamination, frequent consumers of Great Lakes sport caught fish (GLSCF) may be at risk for PCB and DDE accumulation. To examine this problem, the Health Departments of Wisconsin, Illinois, Indiana, Ohio, and Michigan formed a health assessment consortium. Participants were contacted by telephone to complete a detailed demographic and fish consumption survey. Frequent and infrequent GLSCF consumers were identified, and a participant subset was then asked to donate blood for PCB and DDE analysis. Analysis of variance (ANOVA) was done to study exposure group mean differences, while correlation and regression analyses were performed to examine relationships between demographic characteristics, GLSCF consumption, PCB, and DDE body burdens. A total of 4206 individuals participated in the study. Of these, 2542 were habitual GLSCF consumers (mean greater than 35 meals/year males; greater than 27 meals/year females), while 1664 did not eat GLSCF. A subset of 538 participants donated blood and included 439 frequent and 99 infrequent GLSCF consumers. PCB levels were significantly higher in the group of GLSCF consumers (geometric mean: 4.8 ppb males, 2.1 ppb females) when compared to their referents (geometric mean: 1.5 ppb males, 0.9 ppb females), while DDE levels were also higher for GLSCF consumers. PCB and DDE body burdens varied by exposure group, gender, and great lake (Michigan, Huron, Erie). PCB and DDE levels were significantly correlated to age, body mass index, and sport fish and Great Lakes sport fish consumption histories. Regression analysis identified years of consuming sport caught fish as the most robust predictor of PCBs (r2=25%), while age was the best predictor of DDE levels (r2=21%). This study corroborated previous findings relating frequent GLSCF consumption to a higher body burden for PCBs and DDE.

Adolescent↗
PubMed1998

Phosphorylation regulates the delivery of MHC class II invariant chain complexes to antigen processing compartments.

Transport of newly synthesized MHC class II glycoproteins to endosomal Ag processing compartments is mediated by their association with the invariant chain (Ii). Targeting to these compartments is dependent upon recognition of leucine-based endo. somal/lysosomal targeting motifs in the Ii cytosolic domain. Ii, like many molecules that contain leucine-based endosomal targeting motifs, is phosphorylated in vivo. In this report we demonstrate that the cytosolic domain of the p35 Ii isoform is phosphorylated in class II Ii complexes isolated from human B lymphoblastoid cell lines or freshly obtained PBMC. Mutation of serine residue 6 or 8 prevents phosphorylation of Ii-p35 expressed in HeLa cells. Treatment of B lymphoblastoid cell lines with the serine/threonine kinase inhibitor staurosporine prevented Ii phosphorylation and significantly delayed trafficking of newly synthesized class II Ii complexes to endosomal Ag processing compartments. By contrast, staurosporine had no effect on the rate of transport of class I or class II glycoproteins through the Golgi apparatus and did not inhibit the delivery of the chimeric molecule Tac-DM, to endocytic compartments, suggesting that staurosporine does not nonspecifically inhibit protein transport to the endocytic pathway. These results demonstrate that phosphorylation regulates the efficient targeting of MHC class II Ii complexes to Ag processing compartments and strongly suggest that this effect is mediated by phosphorylation of the MHC class II-associated Ii chain.

Antigen Presentation↗
PubMed1998

Targeting of SNAP-23 and SNAP-25 in polarized epithelial cells.

SNAP-23 is the ubiquitously expressed homologue of the neuronal SNAP-25, which functions in synaptic vesicle fusion. We have investigated the subcellular localization of SNAP-23 in polarized epithelial cells. In hepatocyte-derived HepG2 cells and in Madin-Darby canine kidney (MDCK) cells, the majority of SNAP-23 was present at both the basolateral and apical plasma membrane domains with little intracellular localization. This suggests that SNAP-23 does not function in intracellular fusion events but rather as a general plasma membrane t-SNARE. Canine SNAP-23 is efficiently cleaved by the botulinum neurotoxin E, suggesting that it is the toxin-sensitive factor previously found to be involved in plasma membrane fusion in MDCK cells. The localization of SNAP-25 in transfected MDCK cells was studied for comparison and was found to be identical to SNAP-23 with the exception that SNAP-25 was transported to the primary cilia protruding from the apical plasma membrane, which suggests that subtle differences in the targeting signals of both proteins exist. In contrast to its behavior in neurons, the distribution of SNAP-25 in MDCK cells remained unaltered by treatment with dibutyryl cAMP or forskolin, which, however, caused an increased growth of the primary cilia. Finally, we found that SNAP-23/25 and syntaxin 1A, when co-expressed in MDCK cells, do not stably interact with each other but are independently targeted to the plasma membrane and lysosomes, respectively.

Animals↗
PubMed1998

The spectrum of respiratory disease associated with exposure to metal working fluids.

Occupational respiratory diseases have been reported following exposure to metal working fluids. We report a spectrum of respiratory illnesses occurring in an outbreak in 30 workers of an automobile parts engine manufacturing plant. Workers presented with respiratory complaints and, after clinical and laboratory evaluations, were classified as those having hypersensitivity pneumonitis, occupational asthma, or industrial bronchitis, or those without occupational lung disease. Hypersensitivity pneumonitis affected seven workers, with six exhibiting serum precipitins to Acinetobacter Iwoffii. Occupational asthma and industrial bronchitis affected 12 and six workers, respectively. Oil-mist exposures were below current recommendations. Gram-negative bacteria, but no fungi, Thermophiles, or Legionella, were identified. Although specific agents responsible for each individual case could not be identified, probably both specific sensitizing agents and non-specific irritants from metal working fluids, additives, or contaminants contributed to this spectrum of occupational respiratory illness.

Adult↗
PubMed1998

MHC class I molecules are enriched in caveolae but do not enter with simian virus 40.

Simian virus 40 (SV40) binds to MHC class I molecules anywhere on the cell surface and then enters through caveolae. The fate of class I molecules after SV40 binding is not known. Sensitivity of 125I-surface-labelled class I molecules to papain cleavage was used to distinguish internalized class I molecules from class I molecules remaining at the cell surface. Whereas the caveolae-enriched membrane microdomain was found to also be enriched for class I molecules, no internalized papain-resistant 125I-surface-labelled class I molecules could be detected at any time in either control cells or in cells preadsorbed with saturating amounts of SV40. Instead, 125I-surface-labelled class I molecules, as well as preadsorbed 125I-labelled anti-class I antibodies, accumulated in the medium, coincident with the turnover of class I molecules at the cell surface. The class I heavy chains that accumulated in the medium were truncated and their release was specifically prevented by the metalloprotease inhibitor 1,10-phenanthroline. Thus, whereas class I molecules mediate SV40 binding, they do not appear to mediate SV40 entry.

Animals↗
PubMed1998

Profiles of Great Lakes critical pollutants: a sentinel analysis of human blood and urine. The Great Lakes Consortium.

To determine the contaminants that should be studied further in the subsequent population-based study, a profile of Great Lakes (GL) sport fish contaminant residues were studied in human blood and urine specimens from 32 sport fish consumers from three Great Lakes: Lake Michigan (n = 10), Lake Huron (n = 11), and Lake Erie (n = 11). Serum was analyzed for 8 polychlorinated dioxin congeners, 10 polychlorinated furan congeners, 4 coplanar and 32 other polychlorinated biphenyl (PCB) congeners, and 11 persistent chlorinated pesticides. Whole blood was analyzed for mercury and lead. Urine samples were analyzed for 10 nonpersistent pesticides (or their metabolites) and 5 metals. One individual was excluded from statistical analysis because of an unusual exposure to selected analytes. Overall, the sample (n = 31) consumed, on average, 49 GL sport fish meals per year for a mean of 33 years. On average, the general population in the GL basin consume 6 meals of GL sport fish per year. The mean tissue levels of most persistent, bioaccumulative compounds also found in GL sport fish ranged from less than a twofold increase to that of PCB 126, which was eight times the selected background levels found in the general population. The overall mean total toxic equivalent for dioxins, furans, and coplanar PCBs were greater than selected background levels in the general population (dioxins, 1.8 times; furans, 2.4 times; and coplanar PCBs, 9.6 times). The nonpersistent pesticides and most metals were not identified in unusual concentrations. A contaminant pattern among lake subgroups was evident. Lake Erie sport fish consumers had consistently lower contaminant concentrations than consumers of sport fish from Lake Michigan and Huron. These interlake differences are consistent with contaminant patterns seen in sport fish tissue from the respective lakes; GL sport fish consumption was the most likely explanation for observed contaminant levels among this sample. Frequent consumers of sport fish proved to be effective sentinels for identifying sport fish contaminants of concern. In the larger study to follow, serum samples will be tested for PCBs (congener specific and coplanar), DDE, dioxin, and furans.

Animals↗
PubMed1997

Streamwater nitrate concentrations in six agricultural catchments in Scotland.

The concentrations of nitrate-N (NO3-N) in catchment inputs and outputs have been compared and contrasted between 6 farm catchments in Scotland, 3 in the West and 3 in the North-East. Forms of intensive animal farming ranging between beef and dairy cattle, sheep and poultry give different sources for potential NO3-N leakage from the systems. While stream reaches bordered by intensive cereal production give rise to the largest inputs to surface waters, climatic influences result in the more-efficient use of fertilizer- and farm waste-N in the West, and an enhanced potential for N-loss to waters in the cooler North-East, regardless of the N-inputs being considerably lower in the latter region. Although the EC Nitrate Directive limit of 11.3 mg NO3-N 1(-1) was not exceeded, peak values occurring during summer baseflows and autumn soil rewetting were commonly larger than the 'target' maximum concentration of 5.65 mg NO3-N 1-1.

Agriculture↗
PubMed1997

Correlations among human blood levels of specific PCB congeners and implications for epidemiologic studies.

Specific congeners of PCBs may differ with respect to their human health risks. For epidemiologic studies, however, measuring levels of specific congeners--as compared with estimating the concentration of total PCBs present, may be of limited value if levels of specific congeners are highly correlated. We examined the correlations among levels of specific congeners in three groups: controls from a case-control study of breast cancer in North Carolina and two groups from Wisconsin with exposure to fish from contaminated waters. Levels of specific congeners were, in general, highly correlated (Pearson r > 0.80). However, the level of congener 180, a heptachlorobiphenyl, tended to be less correlated with levels of lower-chlorinated biphenyls. Among the implications of these findings are that measurement of a select group of congeners may yield essentially the same information as measurement of a large panel, and may be more cost efficient.

Adult↗
PubMed1996

Silicosis among foundry workers. Implication for the need to revise the OSHA standard.

To evaluate the risk of pneumoconiosis among workers in a Midwestern automotive foundry, medical records and silica sand exposure data were analyzed for 1,072 current and retired employees with at least 5 years of employment as of June 1991. Approximately half of these employees had worked at the foundry for 20 or more years. Sixty workers were found to have radiographic evidence of pneumoconiosis. Twenty-eight workers had radiographs consistent with silicosis, of which 25 were consistent with simple silicosis and three with progressive massive fibrosis. The prevalence of radiographic changes consistent with silicosis increased with: number of years worked at the foundry (6% for 20-29 years and 12% for 30 or more years); cigarette smoking (12.2% among smokers with high silica exposure vs. 4.4% among never smokers with high silica exposure); work area within the foundry (cleaning room, core room, mold area, core knockout); and quantitative silica exposure (0.3-2.7% of workers at the current Occupational Safety and Health Administration (OSHA) standard and 4.9-9.9% of workers above the OSHA standard). In addition, the odds of developing radiographic changes consistent with silicosis were increased for African Americans (odds ratio = 2.14, 95% confidence interval 0.85-5.60) in comparison with whites. (The risk was similar when silica exposure was equal, but African-American workers on average had greater exposure to silica, despite having a similar duration of work as white workers.) Another eight workers had radiographic evidence of asbestosis, and 24 had pleural plaques. These asbestos-related changes were not associated with increasing exposure to silica but rather were associated with being in the maintenance department and performing repair work. After controlling for cigarette smoking, race, and exposure to silica at another job besides the foundry, the authors found a 1.45 increased risk of developing a radiograph consistent with silicosis after 20 years of work at the current OSHA standard, and a 2.10 increased risk after 40 years of work at the current OSHA standard. On the basis of these findings, the authors recommend maintaining silica air levels no higher than the exposure level of 0.05 mg/m3 recommended by the National Institute for Occupational Safety and Health.

Black People↗
PubMed1996

Bound simian virus 40 translocates to caveolin-enriched membrane domains, and its entry is inhibited by drugs that selectively disrupt caveolae.

Simian virus 40 (SV40) entry leading to infection occurred only after the virus was at the cell surface for 1.5 to 2 h. SV40 infectious entry was not sensitive to cytosol acidification, a treatment that blocks endocytosis via clathrin-coated vesicles. Instead, SV40 infectious entry was blocked by treating cells with the phorbol ester PMA or nystatin, which selectively disrupts caveolae. In control experiments, transferrin internalization was sensitive to cytosol acidification but was not sensitive to PMA or nystatin. Also, absorbed transferrin entered cells within minutes. Finally, bound SV40 translocated to caveolin-enriched membrane complexes isolated by a Triton X-100 insolubility protocol. Treatment with nystatin did not impair SV40 binding but did block the partitioning of virus into the caveolin-enriched complexes.

Animals↗
PubMed1996

Extracellular simian virus 40 induces an ERK/MAP kinase-independent signalling pathway that activates primary response genes and promotes virus entry.

Simian virus 40 (SV40) binding to growth-arrested cells activated an intracellular signalling pathway that induced the up-regulation of the primary response genes c-myc, c-jun and c-sis within 30 min and of JE within 90 min. The up-regulation of the primary response genes occurred in the presence of cycloheximide and when UV-inactivated SV40 was adsorbed to cells. SV40 binding did not activate Raf or mitogen-activated protein kinase (MAP/ERK1), or mobilize intracellular Ca2+. The SV40-induced up-regulation of c-myc and c-jun was blocked by the tyrosine kinase inhibitor, genistein, and by the protein kinase C (PKC) inhibitor, calphostin C, but not by expression of the MAP kinase-specific phosphatase, MKP-1. These results suggest that the SV40-induced signalling pathway includes the activities of a tyrosine kinase and a Ca(2+)-independent isoform of PKC, but not of Raf or MAP kinase. Finally, SV40 infectious entry into cells was specifically and reversibly blocked by genistein.

Animals↗
PubMed1996

Wisconsin farmer cancer mortality, 1981 to 1990: selected malignancies.

Cancer mortality risks for Wisconsin white male farmers were examined during the years 1981 to 1990. Four malignancies were studied: Non-Hodgkin's lymphoma, melanoma, colon cancer, and rectal cancer. Occupation coded deaths were segmented into farmer and nonfarmer groups and population counts for the groups were estimated from 1980 and 1990 Bureau of the Census data. Standardized mortality ratios (SMRs) were constructed from the ratio of observed farmer deaths and the expected number of farmer deaths. Expected deaths were generated from the underlying statewide nonfarmer rate for the malignancy multiplied into the farmer population at risk. Farmers had significantly lower mortality risks for melanoma (SMR: 0.659; 95% CI: 0.993-0.326) and colon cancer (SMR: 0.763; 95% CI: 0.928-0.599). Farmers also exhibited a nonsignificant decrement for non-Hodgkin's lymphoma (SMR: 0.930; 95% CI: 1.214-0.645). For rectal cancer, farmers experienced a slightly higher but essentially the same risk as nonfarmers (SMR: 1.013; 95% CI: 1.418-0.608)--the SMR was not significant. This study corroborates a number of cancer incidence and mortality investigations demonstrating that farmers generally experience the same or lower mortality risks for these malignancies.

Agriculture↗
PubMed1996

Surveillance in environmental public health: issues, systems, and sources.

This article describes environmental public health surveillance and proposes a framework to enhance its practice in the United States. Special issues for surveillance in environmental public health are examined, and examples of existing systems useful for environmental public health practice are provided. Current and projected surveillance needs, as well as potential sources of data, are examined. The proposed framework for conducting environmental public health surveillance involves data from three points in the process by which an agent in the environment produces an adverse outcome in a host: hazards, exposures, and outcomes. Environmental health practitioners should build on efforts in other fields (e.g., infectious diseases and occupational health) to establish priorities in the surveillance of health conditions associated with exposure to environmental toxicants. For specific surveillance programs, existing data systems, as well as data gaps, should be identified. Coordinated surveillance systems can facilitate public health efforts to prevent and control disease, injury, and disability related to the interaction between people and their environment.

Environmental Exposure↗
PubMed1995

Imported seabass as a source of mercury exposure: a Wisconsin case study.

The Wisconsin Division of Health investigated mercury exposure in a 40-year-old man, his 42-year-old wife, and their 2.5-year-old son. At the time of our investigation, these individuals had blood mercury levels ranging from 37 to 58 micrograms/L (normal < 5 micrograms/L) and hair samples from the adults contained 10-12 micrograms mercury/g dry weight. A personal interview and home inspection failed to identify any occupational or household sources of mercury exposure. The family's diet included three to four fish meals per week. The fish was purchased from a local market and included Lake Superior whitefish, Lake Superior trout, farm-raised trout and salmon, and imported seabass. Analysis of these fish found that only one species, the imported seabass, contained significant mercury levels. Two samples of the seabass obtained from the vendor on different days contained mercury concentrations of 0.5 and 0.7 mg/kg. Based on consumption estimates, the average daily mercury intakes for these individuals ranged from 0.5 to 0.8 micrograms/kg body weight. Six months after the family stopped consuming the seabass, blood mercury levels in this man and woman were 5 and 3 micrograms/L, respectively. Analysis of sequential blood samples confirmed that mercury elimination followed first-order kinetics with a half-life of approximately 60 days.

Adult↗
PubMed1994

Trends in the surgical treatment of prostate cancer in Wisconsin, 1989-1991.

BACKGROUND: Radical prostatectomy (removal of the prostate gland and seminal vesicles) is usually considered a definitive treatment for localized prostate cancer. Although a sharp increase and wide geographic variation in radical prostatectomy rates have been recently documented, the reasons for this increase and the factors that make men diagnosed with the disease more likely to be treated surgically are not well known. PURPOSE: Our purpose was to examine trends in the use of surgical treatment for prostate cancer, as well as the factors associated with the choice of surgical treatment and how these factors changed in Wisconsin in the period 1989 through 1991. METHODS: We carried out a population-based cohort study. A cohort of Wisconsin men diagnosed from 1989 through 1991 with prostate cancer was identified through the Wisconsin cancer reporting system. To determine which men diagnosed with prostate cancer were treated with surgery, we linked prostate cancer records to the Wisconsin hospital discharge database. The outcome measured was radical prostatectomy within 6 months from the date of the diagnosis of prostate cancer. RESULTS: The yearly number of prostate cancer cases reported from 1989 through 1991 rose 33%, from 2468 to 3278. During the same period, the yearly number of radical prostatectomies rose 226%, from 283 to 922. Patients diagnosed in 1991 were twice as likely to have surgery as those diagnosed in 1989, the proportion of cases receiving surgical treatment rising from 12% to 25%. Patients who were white, less than 65 years of age, had a cancer reported to be at regional stage, and who were first reported by large hospitals were more likely to be treated surgically. CONCLUSIONS: The use of surgery to treat prostate cancer has increased dramatically in Wisconsin, doubling in a 3-year period, despite the fact that studies have not shown surgery to be more effective than other options for many patients. The increase observed in the rate of surgery was about the same across age, race, stage at diagnosis, and hospital size. The reasons for this increase are probably multifactorial. IMPLICATIONS: Risks, costs, and benefits of surgical treatment should be carefully compared with those of alternative management approaches. Patients should be enabled to make an informed decision, based on the current best evidence, on the treatment option they prefer.

Aged↗
PubMed1993

Silicosis surveillance--Michigan, New Jersey, Ohio, and Wisconsin, 1987-1990.

PROBLEM/CONDITION: Improved surveillance for silicosis is needed to target interventions to prevent this occupational lung disease caused by the inhalation of crystalline silica dust. REPORTING PERIOD COVERED: 1987-1990. DESCRIPTION OF SYSTEMS: State-based silicosis surveillance and intervention programs have been developed in Michigan, New Jersey, Ohio, and Wisconsin as part of the Sentinel Event Notification System for Occupational Risks (SENSOR) Program, initiated in 1987 by the National Institute for Occupational Safety and Health (NIOSH). RESULTS: From 1987 through 1990, the SENSOR program confirmed a total of 430 cases of silicosis reported from these four states. Overall, approximately 60% of these cases were in workers employed in primary metal industries, although the types of industries in which cases occurred varied by state. Some cases were attributable to relatively recent exposure, including new cases in seven persons first exposed since 1980 in New Jersey. Silicosis case reports have prompted measurement of respirable silica concentrations at 25 Michigan work sites, and 14 (56%) of these sites were found to have levels that exceeded the legally permissible exposure level. INTERPRETATION: The silicosis surveillance and intervention strategies piloted by state health departments in the NIOSH-funded SENSOR Program have demonstrated the feasibility and effectiveness of identifying specific silica-using work sites that need preventive intervention. ACTIONS TAKEN: On the basis of initial experience in these four states, NIOSH developed guidelines for state-based silicosis surveillance and awarded SENSOR cooperative agreements to three additional states where the applicability of these surveillance methods will be further evaluated.

Humans↗