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S L Sauter

Publications and source records attributed to S L Sauter.

10 recordsLinked to original sources
PubMed1992

Expression of carcinoembryonic antigen and its predicted immunoglobulin-like domains in HeLa cells for epitope analysis.

Carcinoembryonic antigen (CEA) is a member of the immunoglobulin gene superfamily with one predicted variable domain-like region (N domain; 108 amino acids) and three sets of constant domain-like regions (A1B1, A2B2, and A3B3; 92 amino acids for A domains and 86 amino acids for B domains). In addition, CEA possesses two signal peptides, one at the amino terminus and one at the carboxyl terminus. Both are removed during posttranslational processing, with the one at the carboxyl terminus being replaced by a glycosylphosphatidylinositol (GPI) moiety. We have previously expressed the full length complementary DNA clone for CEA in Chinese hamster ovary cells and murine L cells, demonstrating proper processing of nascent polypeptide chains to mature, fully glycosylated CEA including the GPI anchor. Using the same full length CEA complementary DNA clone and the polymerase chain reaction, we have now constructed expression clones for secreted versions of the N domain, the A3B3 domain, and the A3 and B3 subdomains. The clones were expressed in HeLa cells using the beta-actin promoter. A stop codon was introduced at the end of the A3B3 and the A3 and B3 domains to allow secretion instead of retention on plasma membranes with the GPI anchor. Expressed products were purified to homogeneity by affinity chromatography using monoclonal antibodies specific for each domain and by reversed phase high pressure liquid chromatography. Purified domains were characterized by Western blotting, antibody binding and inhibition studies, amino-terminal sequence and amino acid analyses, and laser desorption/time of flight mass spectrometry. These analyses revealed that the monomeric N domain is of size 15,990, with a glycosylation mass of about 4100, in good agreement with two N-linked glycosyl units of about mass 2100. There is some evidence that the N domain forms dimers. The N domain reacted with antibodies specific for this domain with an affinity similar to that of intact CEA. The A3B3 domain had a mass of 34,462, with a glycosylation mass of 14,900, in good agreement with seven N-linked glycosylation sites of average mass 2100. The A3B3 domain reacted only with antibodies specific for this domain, with a slightly lower affinity than that of native CEA. The amino-terminal sequences of the N domain and A3B3 domain proteins demonstrated proper processing of the signal peptide.(ABSTRACT TRUNCATED AT 400 WORDS)

Amino Acid Sequence↗
PubMed1991

Finger tremor after carbon disulfide-based pesticide exposures.

Index finger tremor accompanying voluntary movement was studied in 19 age-matched control subjects and in 19 grain industry employees chronically exposed to carbon disulfide-based fumigants. Visual judgments of tremor amplitude made by neurologists during clinical examinations equaled the sensitivity of computerized tremor amplitude measurements. Tremor frequency variations detectable only with computerized measurement were present in grain workers with and without increased tremor amplitudes. Frequency differences discriminated between normal subjects and 74% of the grain workers. The distribution of tremor frequency power in the grain workers was often sequestered at 5 to 7 Hz, reminiscent of tremor in idiopathic Parkinson's disease. These findings suggest that the measurement of subtle tremor frequency changes may provide an early indication of chronic carbon disulfide poisoning.

Adult↗
PubMed1991

Binding of nonspecific cross-reacting antigen, a granulocyte membrane glycoprotein, to Escherichia coli expressing type 1 fimbriae.

Nonspecific cross-reacting antigen (NCA) is a well-characterized membrane glycoprotein on granulocytes, macrophages, and lung epithelium. Structural studies at the protein and genomic levels have revealed that NCA is a member of the immunoglobulin supergene family, and hybridization studies showed that the transcript level of NCA is induced by treatment with gamma interferon. These studies, as well as the expression of NCA on granulocytes, suggest a role for NCA in immune response. For a first step in studying this possible role, we have examined the binding of two glycoforms of NCA designated NCA-50 (Mr, 50,000) and TEX-75 (Mr, 75,000). Here we report the results from binding assays which demonstrate carbohydrate-mediated binding of Escherichia coli expressing type 1 fimbriae and of isolated type 1 fimbriae to NCA-50. TEX-75 did not bind to the purified fimbriae but bound slightly to the bacterial strain. Inhibition studies showed that the binding to NCA-50 involved interaction of mannose moieties on NCA-50 and lectins on the fimbriae. The binding of NCA-50 to bacterial fimbriae was confirmed by electron microscopy studies, using immunolabeling techniques. In addition, we show that the surface expression of NCA-50 (and presumably of other NCA species) on isolated polymorphonuclear leukocytes is increased following activation with the bacterial peptide formylmethionyl-leucyl-phenylalanine, consistent with a role for NCA in immune response.

Antigens, Neoplasm↗
PubMed1991

Work posture, workstation design, and musculoskeletal discomfort in a VDT data entry task.

Self-report data on musculoskeletal discomfort were collected from several hundred VDT users in two agencies of a state government. Aspects of worker posture and workstation design were objectively assessed for 40 of the VDT users. Multiple regression analyses were used to examine the relationship between these ergonomic variables and musculoskeletal discomfort. Effects of ergonomic factors on musculoskeletal discomfort were clearly evident in the analyses. Regression models explained up to 38% of the variance in discomfort at different body sites. Of special interest was that leg discomfort increased with low, soft seat pans, suggesting that postural constraint is more important than thigh compression as a risk factor for leg discomfort in VDT work. In addition, arm discomfort increased with increases in keyboard height above elbow level, supporting arguments for low placement of the keyboard. Finally, high levels of neck and shoulder girdle discomfort observed in the study population suggest the need for further attention to the control of cervicobrachial pain syndromes in VDT work.

Adult↗
PubMed1990

Prevention of work-related psychological disorders. A national strategy proposed by the National Institute for Occupational Safety and Health (NIOSH).

The National Institute for Occupational Safety and Health (NIOSH) recognizes psychological disorders as a leading occupational health problem. This document, developed by a NIOSH working group led by the present authors, represents a first attempt to fashion a comprehensive national strategy to protect and promote the psychological health of workers. Roles are identified for industry, labor, government, and academia. Key initiatives include (a) steps to improve working conditions and employee mental health services and (b) increased research and surveillance to advance understanding of the problem. Because work-related psychological disorders appear to be a rapidly developing problem lacking complete definition in terms of scope and etiology, this strategy is not to be considered a final statement of NIOSH policy.

Humans↗
PubMed1990

Differences in frequency of finger tremor in otherwise asymptomatic mercury workers.

Tremor was measured from the index finger during low force, position holding in 18 control subjects and 18 battery workers with low level exposure to mercury. All workers were asymptomatic on clinical neurological examination. No differences were found in average tremor amplitudes between the groups, but statistically significant abnormalities in tremor frequency distribution existed. Tremor power spectra in the group of mercury workers were shifted toward the higher frequencies and compressed into narrow frequency peaks. These results suggest that measurements of finger tremor that evaluate the frequency distribution can produce a higher diagnostic yield than traditional visual clinical judgement. The findings also confirm other reports that currently permitted exposures to mercury are associated with subtle but distinctive differences in tremor accompanying voluntary movement.

Adult↗
PubMed1990

Behavioral effects of increased CO2 load in divers.

The behavioral effects of elevated PACO2 were examined to clarify risks due to CO2 retention in diving. In two separate laboratory studies, experienced divers breathed 6% CO2 mixtures under normobaric conditions. Normoxic study: Subjects (n = 8) first breathed air (control); then 6% CO2, 21% O2, balance N2 (exposure); and then air again (postexposure). Hyperoxic study: Subjects (n = 10) first breathed 100% O2; then 6% CO2 in O2; and then O2 again. Subjects performed a test battery in each condition. In the control and postexposure conditions, tests consisted of simple and choice reaction time, postural sway, tremor, and hand steadiness. In the exposure conditions, only the simple and choice reaction time tests were performed. No significant performance decrements during CO2 exposure were found in either study. However, regression analyses indicated that changes in postural sway, tremor, and decision-making time after normoxic CO2 exposure were proportional to decrements in individual end-tidal PCO2 levels following CO2 exposure. We conclude that divers may be at risk for performance impairment immediately after a period of CO2 retention.

Adolescent↗
PubMed1989

Microbreak length, performance, and stress in a data entry task.

The effects of brief rest pauses on performance and well-being were evaluated for a highly repetitive, data entry task. Experienced data entry operators (N = 20) performed the task in a two-day experiment in a simulated office environment. Each day was divided into six, 40-min work periods. Subjects took a brief rest pause at the workstation (microbreak) in the middle of each work period. Subjects were instructed to terminate this microbreak when ready to resume work. Keystroke rate, error rate, correction rate, heart rate and heart rate variability were scored for each half of the work period. In addition, mood states before and during the work period were assessed. Microbreaks were found to average 27.4 s in duration. High ratings of fatigue and boredom during the work period were associated with longer microbreaks, suggesting that the break period was self-adjusted relative to mood state. In addition, correction rate and heart rate were lower following long microbreaks, implying that the degree of recovery was linked to the length of the microbreak. Comparison of keystroke output and correction rate before and after the microbreak, however, revealed that performance worsened after the microbreak, suggesting that subjects terminated microbreaks before complete recovery could occur.

Adolescent↗
PubMed1988

Isolation and characterization of high-molecular mass DNA from hair shafts.

Experiments to identify species by DNA analysis of their hair failed so far because no DNA could be isolated from hair shafts. In this work the preparation of DNA from human--as well as from animal hair shafts (alpaca, angora-rabbit, cashmere, cashgora, mohair, merino and yak) is described for the first time. In general the isolated DNA shows a length of more than 20 kbp. The species of the hair shaft samples could be exactly identified by DNA hybridization experiments. The isolated DNA from hair shafts allow new possibilities to identify species and individuals employing techniques from molecular biology.

Animals↗