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Biomedical subjects

S M Gordon

Publications and source records attributed to S M Gordon.

At least 109 records · Page 6Linked to original sources
PubMed1988

Pyrogenic reactions associated with the reuse of disposable hollow-fiber hemodialyzers.

We investigated 18 pyrogenic reactions (PRs) that occurred between July 1 and 13, 1987, in 16 patients receiving long-term hemodialysis at one dialysis center in Illinois. We defined a case of PR as the onset of chills or fever (oral temperature, greater than or equal to 37.8 degrees C) in a patient who was afebrile and had no signs or symptoms of infection before a dialysis treatment. Pyrogenic reactions to dialysis sessions during the epidemic period (July 1 through 14) were associated with the use of a reused dialyzer (risk ratio, 6.2; 95% confidence interval, 0.8 to 45). The water used to rinse the dialyzers after use and to dilute the germicide for disinfecting the dialyzers contained high concentrations of endotoxins (greater than 6 ng/mL) and bacteria (greater than 10(4) colony forming units/mL). After reuse of dialyzers was discontinued at the center, the PR rate fell to pre-epidemic levels. We concluded that PRs were associated with reuse of dialyzers, probably contaminated with endotoxins. Active surveillance for PRs among patients undergoing long-term hemodialysis should be routine at all dialysis centers; an increase in PRs should prompt timely review of water treatment and dialyzer reprocessing systems.

Bacteria↗
PubMed1988

Neuropsychologically impaired alcoholics: assessment, treatment considerations, and rehabilitation.

Recently there has been a resurgence of interest in the neuropsychological status of the alcoholic. The research documenting neuropsychological deficits has consistently shown impairments in abstract reasoning ability, visuospatial and visuomotor ability, and learning and memory skills. Despite these findings, it appears that many alcohol treatment clinicians interpret patient behavior from a psychological perspective and treatment programs make unwarranted assumptions about patients' ability to profit from standard treatment approaches. This paper discusses these issues, and presents an outline of an innovative cognitive rehabilitation program designed specifically to meet the needs of neuropsychologically impaired alcoholic patients.

Alcoholism↗
PubMed1988

A computerized classification technique for screening for the presence of breath biomarkers in lung cancer.

A simple computer-based screening technique has been developed for classifying human expired air components into 16 chemical classes, based on empirical formulas. The sort procedure was developed to simplify the screening of the composition of expired air samples by sorting all components into chemical classes and classifying components at the greater than 75% and greater than 90% occurrence levels. Both occurrence-rate components are then evaluated as diagnostic markers in a discriminant function model for their ability to detect lung cancer. Of the 386 components detected in the gas chromatography/mass spectrometry (GC/MS) data files, 45 components were present at the greater than 75% occurrence level and 28 components at the greater than 90% occurrence level. Thus, this preliminary sort routine, performed by using a simple macro program installed into a standard personal-computer spread-sheet, greatly reduces the amount of data required for statistical treatment. Such a sort routine can also be applied as easily to other complex GC/MS data files for the purpose of data reduction.

Biomarkers, Tumor↗
PubMed1987

Identification of isoprenoid-type components in human expired air: a possible shunt pathway in sterol metabolism.

Expired air samples have been analyzed from three groups of human subjects (normal, liver dysfunction, lung cancer) and the baboon (Papio anubus). Of the several hundred compounds present, three compounds were of particular interest due to their structural relationship to the isoprenoid-type intermediates in the sterol pathway. These compounds were 1-methyl-4-(1-methyl-ethenyl)-cyclohexene, 6-methyl-5-hepten-2-one, and 6,10-dimethyl-5,9-undecadien-2-one. Hydroxyacetone was also found in all samples screened. The relationship of these compounds to the non-sterol pathway of mevalonate metabolism is discussed.

Animals↗
PubMed1985

Volatile organic compounds in exhaled air from patients with lung cancer.

Using a specially developed breath collection technique and computer-assisted gas chromatography/mass spectrometry (GC/MS), we have identified in the exhaled air of lung cancer patients several volatile organic compounds that appear to be associated with the disease. The GC/MS profiles of 12 samples from lung cancer patients and 17 control samples were analyzed by using general computerized statistical procedures to distinguish lung cancer patients from controls. The selected volatile compounds had sufficient diagnostic power in the GC/MS profiles to allow almost complete differentiation between the two groups in a limited patient population.

Adenocarcinoma↗
PubMed1976

Detection of beta2-microglobulin in sera from diverse vertebrate species by the use of a heterologous radioimmunoassay.

The strong cross-reaction between rabbit and human beta2-microglobulins, as detected by goat antisera, has permitted the development of heterologous radioimmunoassays to detect homologues of beta2-microglobulin (beta2mu) in the sera of various vertebrate species. The assay based on the inhibition of the binding reaction between goat anti-rabbit beta2 mu and human beta2 mu divided the sera examined into two groups, one giving high levels of inhibition (approximately 80%). and the other lower levels (approximately 20%). There was no evident correlation between this division and phylogenetic classification. When the same group of sera was tested using the assay based on the inhibition of binding of rabbit beta2 mu to goat anti-human beta2 mu, a wide range of maximal levels of inhibition was observed, with clustering of phylogenetically related species.

Animals↗
PubMedDate not supplied

Residential environmental measurements in the national human exposure assessment survey (NHEXAS) pilot study in Arizona: preliminary results for pesticides and VOCs.

A major objective of the National Human Exposure Assessment Survey (NHEXAS) performed in Arizona was to conduct residential environmental and biomarker measurements of selected pesticides (chlorpyrifos, diazinon), volatile organic compounds (VOCs; benzene, toluene, trichloroethene, formaldehyde, 1,3-butadiene), and metals for total human exposure assessments. Both personal (e.g., blood, urine, dermal wipes, 24 h duplicate diet) and microenvironmental (e.g., indoor and outdoor air, house dust, foundation soil) samples were collected in each home in order to describe individual exposure via ingestion, inhalation, and dermal pathways, and to extrapolate trends to larger populations. This paper is a preliminary report of only the microenvironmental and dermal wipe data obtained for the target pesticides and VOCs, and provides comparisons with results from similar studies. Evaluations of total exposure from all sources and pathways will be addressed in future papers. The pesticides and VOCs all showed log-normal distributions of concentrations in the Arizona population sampled, and in most cases were detected with sufficient frequency to allow unequivocal description of the concentration by media at the 90th, 75th, and 50th (median) percentiles. Those combinations of pollutant and media, in which a large fraction of the measurements were below the detection limit of the analysis method used, included trichloroethene, 1,3-butadiene, and formaldehyde in outdoor air; chlorpyrifos and diazinon in outdoor air; and diazinon in dermal and window sill wipes. In general, indoor air concentrations were higher than outdoor air concentrations for all VOCs and pesticides investigated, and VOC levels were in good agreement with levels reported in other studies. In addition, the agreement obtained between co-located VOC samplers indicated that the low-cost diffusional badges used to measure concentrations are probably adequate for use in future monitoring studies. For the pesticides, the median levels found in indoor samples agreed well with other studies, although the levels corresponding to the upper 0.1-1% of the population were considerably higher than levels reported elsewhere, with indoor air levels as high as 3.3 and 20.5 microg/m3 for chlorpyrifos and diazinon, respectively. These data showed excellent correlation (Pearson and Spearman correlation coefficients of 0.998 and 0.998, respectively) between chlorpyrifos in indoor air and in the corresponding dermal wipes, and relatively poor correlation between chlorpyrifos in dust (microg/g or microg/ml) and dermal wipes (Pearson=0.055 microg/g and 0.015 microg/m2; Spearman=0.644 microg/g and 0.578 microg/m2). These data suggest the importance of dermal penetration of semi-volatiles as a route of residential human exposure.

Air Pollutants↗
PubMedDate not supplied

Evaluations of primary metals from NHEXAS Arizona: distributions and preliminary exposures. National Human Exposure Assessment Survey.

NHEXAS AZ is a multimedia, multipathway exposure assessment survey designed to evaluate metals and other analytes. This paper reports the analyte-specific concentration distributions in each of the media examined (air, soil, house dust, food, beverage, and water), for various methodologies used (inductively coupled plasma-atomic emission spectroscopy and hydride generation-atomic absorption spectroscopy). Results are reported for the five primary metals (Pb, As, Cd, Cr, and Ni). Ingestion was the most important pathway of exposure. Metal concentrations in air were very low (ng/m3) and found only above the 90th percentile. Metals were commonly found in house dust and soil. Exposure transfer coefficients minimize the importance of this component for those over the age of 6 years. When ranked by exposure, food, beverage, and water appeared to be the primary contributors of metal exposure in NHEXAS AZ. For instance, at the 90th percentile, Pb was undetected in air, found at 131 and 118 microg/m3 in floor dust and soil, respectively, and measured at 16 microg/kg in food, 7.1 microg/kg in beverage, and 2.0 and 1.3 microg/l in drinking and tap water, respectively. We calculated preliminary estimates of total exposure (microg/day) for each participant and examined them independently by age, gender, and ethnicity as reported by the subjects in the NHEXAS questionnaire. At the 90th percentile for Pb, total exposures were 64 microg/day across all subjects (n=176); adult men (n=55) had the greatest exposure (73 microg/day) and children (n=35) the least (37 microg/day). Hispanics (n=54) had greater exposure to Pb (68 microg/day) than non-Hispanics (n=119; 50 microg/day), whereas non-Hispanics had greater exposure for all other metals reported. These results have implications related to environmental justice. The NHEXAS project provides information to make informed decisions for protecting and promoting appropriate public health policy.

Adolescent↗
PubMedDate not supplied

Oral herpes simplex virus infection with cardiac transplantation.

Oral herpes simplex virus infection is a common complication of cardiac transplantation. Lesions are secondary to reactivation of the virus, are atypical in appearance, and can involve any oral and perioral surface. Diagnosis on clinical grounds is difficult and should be confirmed with laboratory testing. A case report and review of the literature are presented to support the features of this infection.

Adult↗
PubMedDate not supplied

Dental fear and anxiety as a barrier to accessing oral health care among patients with special health care needs.

Persons with special health care needs due to physical and cognitive impairment can be at increased risk for dental disease which can be attributed to, as well as exacerbate, existing medical conditions. This study assessed the nature of perceived barriers to obtaining oral health care among a special-needs population and the influence of these factors (in particular, fear and anxiety) on utilization of dental services. A total of 27.9% of the sample reported fear/anxiety about dental visits, with approximately half of those reporting to be very nervous or "terrified". There was an inverse relationship between the frequency of dental visits and the proportion of respondents reporting themselves as very nervous or terrified, and between the perception of oral health status and the level of dental fear/anxiety (P < 0.001). A large difference was reported between patient preference for pharmacologic modalities for anxiety control and those received at dental visits, with 40% of the youngest age group indicating that they would go to the dentist more frequently if sedation or general anesthesia were offered. The levels of self-reported fear/anxiety and the high proportion of respondents indicating an unmet need for adjunctive anesthesia services suggest that fear/anxiety acts as a barrier to dental care among this special-needs group which could be ameliorated with greater use of these services.

Activities of Daily Living↗