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Biomedical subjects

T L Thomas

Publications and source records attributed to T L Thomas.

At least 109 records · Page 6Linked to original sources
PubMed1979

Mortality among workers employed in the pharmaceutical industry: a preliminary investigation.

The cause-specific mortality experience of 826 plant employees and 249 sales representatives employed by a large U.S. pharmaceutical firm was examined to determine if there were unusual patterns of fatal disease that might relate to factors in the work environment. Deaths that occurred between 1954 and 1976 among actively employed or retired workers were identified through company records and a proportionate mortality analysis was carried out using the total U.S. as a standard. PMRs were computed for male and for female workers and for several broad occupational categories. A significant difference between observed and expected mortality from suicide was present in both males and females and there was an indication that drug overdoses were over-represented. PMRs for several cancer sites were elevated, but excesses were not always confined to particular occupational categories. Excesses of respiratory cancer were present in male maintenance workers and in female production workers. Increased relative frequencies of melanoma among males and of leukemia among females were confined to the production worker category. Some of the findings may provide leads for further investigations of the pharmaceutical industry.

Adult↗
PubMed1978

Cross-cultural analysis of students' sexual standards.

Our purpose was to investigate, cross-culturally, university students' premarital sexual standards. A number of predictions were derived from the work of Cristensen, Reiss, and Burr. Data were collected via self-administered questionnaires from over 1100 English-speaking respondents in five "cultures" (four countries). These cultural contexts had a strong effect on the attitudes and behavior of individual respondents. As predicted, the difference in the standards held by males and females was small in highly permissive societies. Negative consequences of premarital intercourse (i.e., guilt) were reported by the highest proportion of sexually experienced respondents in the most restrictive society. An unsuccessful effort was made to predict how the correlation between permissiveness and such variables as religiosity would change in different cultures. Across all five cultures, greater courtship participation, less religiosity, greater physical attractiveness, and spending less time with one's family were associated with greater permissiveness. Finally, students from high-status backgrounds were generally more permissive.

Adolescent↗
PubMed1978

Characteristics of individual repetitive sequence families in the sea urchin genome studied with cloned repeats.

Cloned repetitive sequences from the S. purpuratus genome a few hundred to approximately 1000 nucleotides long were used to investigate the characteristics of individual repetitive sequence families. They wer terminally labeled by the kinase procedure and reacted with sheared S. purpuratus DNA. Repetition frequencies were measured for 26 individual families and were found to vary from a few to several thousand copies per genome. Estimates of sequence divergence were made for 18 cloned repeat families by measuring thermal stability of the heteroduplexes formed between the genomic DNA and the cloned fragments, compared with that of the renatured cloned fragments. The difference was less than 4 degrees C for three of the 18 families, and less than 10 degress C for 13 of the 18 families. These 13 repetitive sequence families lack any detectable highly divergent sequence relatives, and the results reported are shown not to change when the renaturation criterion is lowered below 55 degrees C in 0.18 M Na+. Five of the 18 cloned families displayed greater sequence divergence. The average sequence divergence of the total short repetitive sequence fraction of S. purpuratus DNA was found to match closely the average of the divergences of the cloned repeat sequences.

Base Sequence↗
PubMed1978

Increased risk of lymphoma in sicca syndrome.

The risk of cancer was ascertained in 136 women with sicca syndrome followed at the National Institutes of Health (NIH). Seven patients developed non-Hodgkin's lymphoma from 6 months to 13 years after their first admission to NIH. This was 43.8 times (P less than 0.01) the incidence expected from the rates of cancer prevailing among women of the same age range in the general population during this time. In addition, three cases of Waldenström's macroglobulinemia occurred in this study group. Eight patients developed cancers other than lymphoma, similar to the number expected based on the rates prevailing in the general population. Patients with a history of parotid enlargement, splenomegaly, and lymphadenopahy had an increased risk of lymphoma. These clinical conditions did not appear to be early manifestations of undiagnosed lymphoma but rather seemed to identify a subgroup of patients with sicca syndrome with marked lymphoid reactivity, who had a particularly high risk of subsequently developing lymphoma.

Adult↗
PubMed1976

Optimal conditions and specificity of interaction of a distinct class of nonhistone chromosomal proteins with DNA.

A subclass of nonhistone chromatin proteins with high DNA affinity has been isolated from rat liver. The interaction of the isolated proteins with DNA in vitro was characterized utilizing a nitrocellulose filter binding technique. The temperature, time, concentration, ionic strength, and pH dependence were characterized. Optimal interaction was observed at 0.19 M naCl, pH 7.5 with a protein to DNA ratio of 13 (w/w). Equilibrium and kinetic competition experiments indicated that these proteins interact optimally with A-T rich and single-stranded DNA. The data also suggest that these proteins might affect the helixcoil transiton of DNA.

Animals↗
PubMed1976

Gallstone obstruction and perforation of the duodenal bulb.

A case of gallstone ileus is presented in which the stone became impacted in the first part of the duodenum and then caused perforation at the site of impaction. This is only the second published British case of gallstone impaction at this site. Perforation of the duodenum by a gallstone has not previously been recorded. The clinical and radiological features of this case are discussed.

Aged↗
PubMed1976

DNA unwinding component of the nonhistone chromatin proteins.

A subclass of nonhistone chromatin proteins from rat liver, previously shown to exhibit high affinity for DNA, has been fractionated by single-stranded DNA-agarose affinity chromatography. The protein fraction that bound to DNA-agarose in 0.19 M NaCl-buffer and was eluted with 2 M NaCl-buffer is enriched for a protein component of approximately 20,000 daltons and exhibits preferential binding to denatured DNA. This nonhistone protein fraction specific for single strands binds to DNA in a non-species-specific manner, and causes helix-coil transition of synthetic poly[d(A-T)-d(A-T)] at 25 degrees, as indicated by the increase in absorbance of ultraviolet light at 260 nm. The observed hyperchromicity does not result from any nuclease activity in the protein fraction, because addition of Mg+2 results in partial hypochromic shift, and the protein/DNA complex is retained by nitrocellulose filters.

Animals↗
PubMed1973

Some binding parameters of chromatin acidic proteins with high affinity for deoxyribonucleic acid.

A fraction of chromatin acidic protein from rat liver, predominantly comprised of low-molecular-weight species, showed highest in vitro affinity for DNA when compared with other fractions of nuclear acidic protein. Maximum binding of this protein fraction was observed at physiological ionic strength of 0.14 M NaCl and DNA/protein ratio > 1. Comparison of their binding to homologous and heterologous DNAs showed partial species specificity. All molecular species of this protein fraction appear to bind to DNA.

Animals↗
PubMedDate not supplied

International emergency medical services: assessment of developing prehospital systems abroad.

Many developing countries are experiencing a greater need for prehospital systems because of urbanization and changing population demographics, leading to greater death rates from trauma and cardiac illnesses. While emergency medical services (EMS) systems may take a variety of forms, they usually contain some system components similar to those found in the United States. In evaluating EMS abroad, it may be useful to compare the developing system type to one of five models of EMS delivery: hospital-based, municipal, private, volunteer, and complex. Using community-based services and available health providers can enable a developing system to function within a primary health network without overtaxing scarce resources. Developing such an approach can lead to creative and effective solutions for prehospital care in developing countries.

Developing Countries↗
PubMedDate not supplied

Exposure of prehospital care providers to violence.

OBJECTIVE: To evaluate the experience of prehospital care providers with violence. METHODS: A survey addressing experiences with prehospital violence was administered to a convenience sample of emergency medical services (EMS) providers in a southern California metropolitan area. Descriptive statistics are reported. RESULTS: Of 774 EMS providers surveyed, 522 (67%) returned the questionnaire. Members of law enforcement were excluded because their experience with violence, weapons, and tactics is not typical of most paramedics. This left a sample of 490 for further analysis. These prehospital care providers had a median of ten years' experience on the job. They tended to be male (93%) and white (80%). All together, 61% recounted assault on the job, with 25% reporting injury from the assault. Respondents reported a median of three episodes, and the number of assaults for each individual was unrelated to the number of years of experience on the job (r = 0.068). Of those injured, 37% required medical attention. On the other hand, 35% reported that their company had a specific protocol for managing violent situations and 28% stated ever having received formal training in the management of violent encounters. This limited training notwithstanding, nearly all (95%) providers described restraining patients. Use of protective gear was reported (73%), and some (19%) admitted to ever carrying a weapon on the job. CONCLUSIONS: By their own report, EMS providers encounter a substantial amount of violence and injury due to assault on the job. Formal training and protocols to provide a standardized safe approach for such encounters are lacking. Although the limitations of survey data are recognized, further research characterizing the level of violence and potential interventions seems warranted.

Adult↗