PubMed HealthSearch

Biomedical subjects

E Sampson

Publications and source records attributed to E Sampson.

18 recordsLinked to original sources

Elevated soluble c-erbB-2 antigen levels in the serum and effusions of a proportion of breast cancer patients.

PURPOSE: An enzyme-linked immunosorbent assay (ELISA) for the extracellular domain of the c-erbB-2 oncogene product was developed and evaluated to determine if soluble c-erbB-2 could be detected in the serum and effusions of cancer patients. PATIENTS AND METHODS: Sera from 208 previously untreated or progressing cancer patients and 69 healthy controls were assayed in a double-antibody sandwich ELISA that used two monoclonal antibodies to the native extracellular domain of the c-erbB-2 receptor. Fisher's exact test was used to analyze the statistical significance of the frequency of elevated serum c-erbB-2 levels. Immunoprecipitation and Western blotting were used to characterize further the c-erbB-2 immunoreactivity in the serum of four breast cancer patients. RESULTS: Sera from 12 of 53 patients (23%) with metastatic or locally advanced breast cancer, zero of 69 controls, one of 31 patients with ovarian cancer (3%), and two of 124 other cancer patients (2%) had soluble c-erbB-2 values greater than or equal to 5 U/mL. The number of breast cancer patients with elevated serum c-erbB-2 levels was significantly greater than that of the control group (P less than .0001), the ovarian cancer group (P less than .03), and the other cancers group (P less than .0001). Also, two of five effusions (40%) from breast cancer patients had an elevated soluble c-erbB-2 antigen level, compared with zero of 17 effusions from patients with benign diseases. Western blotting of four sera from breast cancer patients with elevated serum c-erbB-2 antigen levels produced bands of approximately 105 kD that seemed to correlate in intensity with increasing ELISA serum levels. CONCLUSION: Serum c-erbB-2 levels are elevated in approximately one fourth of patients with locally advanced or metastatic breast cancer.

Adult

Mucoepidermoid odontogenic cyst.

This unusual cystic lesion was previously described as a lesion that has features of both botryoid odontogenic cyst and mucoepidermoid tumor and later was named as glandular odontogenic cyst. An additional case is reported and its clinicopathologic features described. The name "mucoepidermoid odontogenic cyst" is proposed.

Aged

Recombination of bacteriophage lambda in recD mutants of Escherichia coli.

RecBCD enzyme is centrally important in homologous recombination in Escherichia coli and is the source of ExoV activity. Null alleles of either the recB or the recC genes, which encode the B and C subunits, respectively, manifest no recombination and none of the nuclease functions characteristic of the holoenzyme. Loss of the D subunit, by a recD mutation, likewise results in loss of ExoV activity. However, mutants lacking the D subunit are competent for homologous recombination. We report that the distribution of exchanges along the chromosome of Red-Gam-phage lambda is strikingly altered by recD null mutations in the host. When lambda DNA replication is blocked, recombination in recD mutant strains is high near lambda's right end. In contrast, recombination in isogenic recD+ strains is approximately uniform along lambda unless the lambda chromosome contains a chi sequence. Recombination in recD mutant strains is focused toward the site of action of a type II restriction enzyme acting in vivo on lambda. The distribution of exchanges in isogenic recD+ strains is scarcely altered by the restriction enzyme (unless the phage contains an otherwise silent chi). The distribution of exchanges in recD mutants is strongly affected by lambda DNA replication. The distribution of exchanges on lambda growing in rec+ cells is not influenced by DNA replication. The exchange distribution along lambda in recD mutant cells is independent of chi in a variety of conditions. Recombination in rec+ cells is chi influenced. Recombination in recD mutants depends on recC function, occurs in strains deleted for rac prophage, and is independent of recJ, which is known to be required for lambda recombination via the RecF pathway. We entertain two models for recombination in recD mutants: (i) recombination in recD mutants may proceed via double-chain break--repair, as it does in lambda's Red pathway and E. coli's RecE pathway; (ii) the RecBC enzyme, missing its D subunit, is equivalent to the wild-type, RecBCD, enzyme after that enzyme has been activated by a chi sequence.

Bacterial Proteins

Infection control in North American dental schools.

A questionnaire concerning infection control issues was sent to all North American dental schools in 1987. The results were compared with a similar survey conducted by the same authors in 1982. The purposes of the survey were to identify changes that have occurred in dental school infection control policies in the past six to seven years, and to study strengths and weaknesses of current policies. The results of the survey indicate a much greater emphasis on instrument sterilization and the use of barriers during dental treatment than in 1982. Compliance with the policy is not always satisfactory, however. It also shows some inconsistency and confusion in areas dealing with hepatitis B and HIV carrier patients and dental school personnel. Several respondents included written infection control protocols with the questionnaire. Information gained from the survey and the enclosures were used to develop guidelines to help schools improve and update their infection control policies.

Acquired Immunodeficiency Syndrome

Infection control in North American dental schools.

Treatment of patients with transmissible infections is a particular concern in an institutional setting. This paper discusses the results of a questionnaire relating to infection control that was sent to all North American dental schools. The purpose of the survey was to aid in the development of a comprehensive protocol at Marquette University for treating patients with transmissible infections and, in particular, hepatitis B carriers. Currently, the dental community is reluctant to treat patients with a history of hepatitis and hepatitis B carriers. The protection offered by the recently available hepatitis B vaccine should contribute greatly to the reduction of transmission of hepatitis B. It is emphasized that the use of this vaccine in dental schools in no way obviates the need for meticulous infection control protocols.

Canada

A controlled trial of the impact of the family practice nurse on volume, quality, and cost of rural health services.

Rural Newfoundland communities with and without expanded role nurses were compared on a before and after basis. The rural communities are located in a geographically isolated area served by a 40-bed hospital staffed by salaried physicians. Primary care visits within the community increased by 186 per cent after establishment of the family practice nurse community clinic and attendance at the hospital decreased by 35 per cent. Acute care days in hospital decreased 5 per cent in the experimental group and increased by 39 per cent in the control group. A major portion of the community based visits provided to the experimental group were classed as preventive. The total annual health service cost per 1,000 persons in the experimental group increased slightly more than in the control group (26 versus 21 per cent). Adequate management of certain indicator conditions and drugs was maintained by the family practice nurse when compared to the adequacy rating for the physician during the same time period.

Community Health Nursing

Plasma and urinary aldosterone measurement in healthy subjects with a radioimmunoassay kit not requiring chromatography.

We examined the application of a radioimmunoassay kit, not requiring chromatography, to the measurement of aldosterone in healthy human subjects. Plasma aldosterone, urinary aldosterone, and plasma renin activity measurements were performed on samples from 47 subjects under conditions in which dietary sodium intake, posture, and times of sample collection were rigidly controlled. Nomograms are presented to illustrate the continuous, rather well defined, inverse relationship between 24 h sodium excretion and aldosterone measurements in plasma and urine. Mean plasma and urinary aldosterone values for subjects on normal sodium diets were 0.332+/-0.211 nmol/liter and 36.6+/-18.6 nmol/24 h and agreed well with previously reported values. A significant (p less than 0.05 increase in 24 h urinary aldosterone, plasma aldosterone and plasma renin activity resulted with decreased dietary sodium intake and conversely, a significant (p less than 0.05) decrease in each hormone occurred with increased dietary sodium intake. Rising from the supine to upright position resulted in a 230% increase in plasma aldosterone concentrations and a 284% increase in plasma renin activity.

Aldosterone

A pilot epidemiologic study of possible health effects associated with 2,3,7,8-tetrachlorodibenzo-p-dioxin contaminations in Missouri.

In 1971, 2,3,7,8-tetrachlorodibenzodioxin (TCDD)-containing waste oils were sprayed for dust control on residential, recreational, and work areas in Missouri. In several of these areas, the magnitude and the extent of this environmental contamination were not known until late 1982 or 1983. In the first phase of the investigation, a group of persons considered to be at highest risk of exposure and an appropriate comparison group were selected from reviews of Health Effects Survey screening questionnaires. These persons received complete medical examinations and a series of laboratory tests focused on detecting presymptomatic effects in key target organ systems (i.e., hepatic, dermatologic, immunologic, and neurologic effects). Comparisons of these two groups did not produce any firm indications of increased disease prevalence directly related to the putative exposures; of significance is the fact that no cases of chloracne or porphyria cutanea tarda were seen. Nevertheless, no overall definitive conclusion should be based just on this initial pilot study. Insights were provided that are being examined in more refined epidemiologic studies using different designs and strategies--especially of larger, more homogeneous population groups in which exposure status can be better characterized--focused primarily on discerning any potential effects on the urinary tract, liver, neurological, and immune systems. Concurrently, research into the development of replicable laboratory analytical methods and reference ranges for measuring TCDD body burden are being pursued.

Adolescent

The public health response to 2,3,7,8-TCDD environmental contamination in Missouri.

In 1971, waste oil containing 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) was sprayed for dust control on a number of residential, recreational, and work areas in Missouri. In several of them, the level and extent of environmental contamination were not known until late 1982 or 1983. Extrapolation from existing toxicological data indicated the potential for substantial adverse health effects in highly exposed populations. As a result, the Missouri Division of Health and the Centers for Disease Control initiated close collaboration with the Environmental Protection Agency (EPA) on review and evaluation of environmental data, the development of health advisories to EPA on the need for remedial or preventive actions at specific contaminated sites, a health education effort for the medical community and general public, establishment of a dermatological screening clinic, establishment of a central listing of potentially exposed persons through administration of a health effects survey questionnaire, and a pilot medical study of a "highest risk" cohort. Strategies for additional interventions will continue to be based on findings derived from this first phase of the investigation.

Animals