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Biomedical subjects

A G Dean

Publications and source records attributed to A G Dean.

At least 19 recordsLinked to original sources
PubMed2000

Enteritis necroticans (pigbel) in a diabetic child.

BACKGROUND AND METHODS: Enteritis necroticans (pigbel), an often fatal illness characterized by hemorrhagic, inflammatory, or ischemic necrosis of the jejunum, occurs in developing countries but is rare in developed countries, where its occurrence is confined to adults with chronic illnesses. The causative organism of enteritis necroticans is Clostridium perfringens type C, an anaerobic gram-positive bacillus. In December 1998, enteritis necroticans developed in a 12-year-old boy with poorly controlled diabetes mellitus after he consumed pig intestines (chitterlings). He presented with hematemesis, abdominal distention, and severe diabetic ketoacidosis with hypotension. At laparotomy, extensive jejunal necrosis required bowel resection, jejunostomy, and ileostomy. Samples were obtained for histopathological examination. Polymerase-chain-reaction (PCR) assay was performed on paraffin-embedded bowel tissue with primers specific for the cpa and cpb genes, which code for the alpha and beta toxins produced by C. perfringens. RESULTS: Histologic examination of resected bowel tissue showed extensive mucosal necrosis, the formation of pseudomembrane, pneumatosis, and areas of epithelial regeneration that alternated with necrotic segments--findings consistent with a diagnosis of enteritis necroticans. Gram's staining showed large gram-positive bacilli whose features were consistent with those of clostridium species. Through PCR amplification, we detected products of the cpa and cpb genes, which indicated the presence of C. perfringens type C. Assay of ileal tissue obtained during surgery to restore the continuity of the patient's bowel was negative for C. perfringens. CONCLUSIONS: The preparation or consumption of chitterlings by diabetic patients and other chronically ill persons can result in potentially life-threatening infectious complications.

Animals↗
PubMed1999

Distribution of Epi Info software: an evaluation using the Internet.

INTRODUCTION: Epi Info and Epi Map are computer programs for word processing, database management, epidemiologic statistics, and mapping designed for public health professionals. The programs are in the public domain, and distribution outside the Centers for Disease Control and Prevention (CDC) has been through a variety of informal channels. METHOD: Individuals and organizations known to have distributed Epi Info or Epi Map since 1987 provided information. Distributors included CDC, the World Health Organization (WHO), commercial vendors, translators, instructors in university and public health settings, and other public health professionals. Reports documented a minimum number of 145,320 copies distributed. CONCLUSIONS: Since 1994, the Internet has become a major means of propagation, accounting for 66% of the copies for which the method of distribution was known. The Internet also was a major information source for this study.

Centers for Disease Control and Prevention, U.S.↗
PubMed1998

DoEpi. Computer-assisted instruction in epidemiology and computing and a framework for creating new exercises.

DoEpi is a series of computer exercises and a framework for making new exercises based on the Epi Info programs for epidemiologic computing. The system contains three outbreak investigations, a research survey, four exercises in advanced Epi Info programming, and four exercises in public health surveillance. The exercises are available via the Internet (www.cdc.gov, under "Publications, Products, and Software") with provision for CME and CEU credit from the Centers for Disease Control and Prevention. They can serve as a useful adjunct to lectures and textbooks in teaching epidemiology or epidemiologic computing. A new DoEpi exercise with hypertext, low-resolution photographs, questions, answers, and an examination can be constructed in hours rather than weeks or months using an Exercise Development "wizard" provided as part of the instructor's module. Epi Info exercises with data files and customized programs require more work to construct but can be added by those with the necessary skills. DoEpi exercises can be used in a variety of ways for different curricula and students of different background levels, including those with English as a second language. Translation of DoEpi exercises into other languages is facilitated by the instructor's module, and construction of new exercises with locally suitable materials is encouraged. DoEpi is based on DOS programs to allow the widest use. The format lends itself to conversion to hypertext programs in the Microsoft Windows and Internet formats at a future date.

Centers for Disease Control and Prevention, U.S.↗
PubMed1993

Evaluation of a method for detecting aberrations in public health surveillance data.

The detection of unusual patterns in routine public health surveillance data on diseases and injuries presents an important challenge to health workers interested in early identification of epidemics or clues to important risk factors. Each week, state health departments report the numbers of cases of about 50 notifiable diseases to the Centers for Disease Control and Prevention, and these reports are published weekly in the Morbidity and Mortality Weekly Report. A new analytic method and a horizontal bar graph were introduced in July 1989 to facilitate easy identification of unusual numbers of reported cases. Evaluation of the statistical properties of this method indicates that the results are fairly robust to nonnormality and serial correlation of the data. An epidemiologic evaluation of the method after the first 6 months showed that it is useful for detection of specific types of aberrations in public health surveillance.

Bias↗
PubMed1990

Software for data management and analysis in epidemiology.

The collection of data is a lengthy and time-consuming process, but is not an end in itself. For the data to be useful, it is necessary for an appropriate analysis to be made and its results applied. This article describes a computer program for the analysis of epidemiological studies.

Data Interpretation, Statistical↗
PubMed1988

Adjusting morbidity ratios in two communities using risk factor prevalence in cases.

Available data on cancer incidence for 1969-1971 showed statistically elevated rates for breast cancer in St. Louis Park, Minnesota, a community with creosote contamination of the water supply, when compared with the rest of the Minneapolis-St. Paul area taken as the reference population. In order to assess the effect of other known risk factors for breast cancer, 75 persons with breast cancer in each of the two populations were interviewed to obtain frequencies of known risk factors. An adjusted morbidity ratio in the two populations and an expected case rate in the exposed community were calculated from these frequencies, using relative risk values from the medical literature. The adjusted morbidity ratio was less than 1.0, and the observed rate was almost identical to the new expectation, although the age-adjusted rates alone had suggested a significant difference in incidence. This method makes use of relative risks from published studies rather than those associated with local cases and controls. It allows more refined evaluation of differences in cancer rates between communities than can be provided by age- and sex-specific calculations alone, and may allow use of available statistics in situations where cost, temporal considerations, or population size do not favor large new studies.

Adult↗
PubMed1985

Evidence for exposure to HTLV-III in Uganda before 1973.

Fifty of 75 serum samples collected in the West Nile district of Uganda between August 1972 and July 1973 contained antibodies reactive with human T-cell leukemia (lymphotropic) virus type 3 (HTLV-III; mean titer, 601), while 12 of 75 samples were positive in a similar test for HTLV type 1 (HTLV-1) antibodies (mean titer, 236). The samples were screened by enzyme-linked immunosorbent assay and positive results were confirmed by a newly developed unlabeled antibody-peroxidase procedure with enhanced sensitivity for detection of antibody binding to immunoblots of HTLV-III antigen, demonstrating antibodies to proteins with molecular weights of 24,000, 41,000, and 76,000 in nearly all positive samples. Analysis of titration data indicated enhanced titers of antibody against HTLV-III and HTLV-I when coinfection occurred. The high prevalence and relatively low titers [compared to serum from patients with acquired immune deficiency syndrome (AIDS)] of antibodies recognizing HTLV-III proteins in sera from this population at a time that may predate or coincide with the appearance or spread of the AIDS agent (HTLV-III) suggest that the virus detected may have been a predecessor of HTLV-III or is HTLV-III itself but existing in a population acclimated to its presence. It further suggests an African origin of HTLV-III.

Acquired Immunodeficiency Syndrome↗
PubMed1983

A 1957 outbreak of Legionnaires' disease associated with a meat packing plant.

Retrospective study shows that a 1957 outbreak of pneumonia in Austin, Minnesota, was Legionnaires' disease. Between June 7 and August 9, 1957, 78 persons were hospitalized with acute respiratory disease of unknown cause. Most had fever, headache, cough, and pneumonitis; two died. Ages ranged from 14-83 years; half of the patients were aged 55 years or older. Eighty-seven per cent were men. There were no secondary cases. Forty-six (59%) of the 78 patients were employees at a local meat packing plant, in distinction to the area's total working population (32%). Serosurvey of 15 of the 1957 outbreak cases and 30 controls matched for age, sex, and either occupation or residence was carried out in 1979. Antibody titers were determined for Legionella pneumophila serogroups 1-4 by means of indirect immunofluorescence. Twelve (80%) of the 15 cases and 13 (43%) of the 30 controls had antibody titers of 1:64 or greater to one or more of the L. pneumophila serogroups. Significant differences in L. pneumophila antibody titers (prevalence and level) were found between cases and control groups matched for residence (serogroups 1-3) or occupation (serogroups 2 and 3). Only three of 20 Austin residents with pneumonia diagnosed between 1978 and 1980 had L. pneumophila antibody titers of 1:128 or greater (p less than 0.001), in comparison to cases. These serologic data and the 1957 clinical and epidemiologic observations support the contention that this is the earliest documented outbreak of Legionnaires' disease.

Adolescent↗
PubMed1982

An epidemic of Kawasaki syndrome in Hawaii.

A community-wide outbreaks of Kawasaki syndrome, apparently the first in the United States, occurred in Hawaii in the first half of 1978. Twenty-seven of the 33 cases were subjected to intensive epidemiologic and microbiologic study. Patients with Kawasaki syndrome, compared to the general population, more often had Japanese ancestry, high-income status, and possibly a history of respiratory infection in the preceding month (44%). Staphylococcus aureus was not found in high frequency in the patients (15%), and viral cultures and serologic studies, immune electron microscopy, and guinea pig and primate inoculation did not reveal a causative microorganism. Febrile illnesses in guinea pigs inoculated with a skin biopsy specimen should not be further passaged.

Child↗