Search PubMed⌕ Search

Biomedical subjects

M Nelson

Publications and source records attributed to M Nelson.

At least 253 records · Page 14Linked to original sources

Development of a scoring system to judge the scientific quality of information from case-control and cohort studies of nutrition and disease.

A scoring system was developed to help judge the scientific quality of observational epidemiologic studies linking diet with risk of cancer. The scoring system was developed from key headings used in developing research protocols and included questions under headings: three for case-control studies (dietary assessment, recruitment of subjects, and analysis) and four for cohort studies (dietary assessment, definition of cohort, ascertainment, and analysis). Points were awarded for questions in each section, and a total score was derived. Interobserver variation was assessed for five case-controls and five cohort studies for 13 observers: 1 observer repeated the assessment of each paper. Absolute scores and ranking within observer were assessed. There was good agreement between observers in the ranking of studies. Papers that scored higher presented sufficient detail to enable the questions in the scoring system to be answered more easily. For some studies, the information required was either not collected or, if it was collected, not presented. In either case, the frequent lack of information available to judge papers raises questions about the editorial policy and review process of journals publishing dietary studies as much as it does about the scoring system. Applying the scoring system to a review of meat and cancer risk suggested that, taking the score into account, from what seemed like a large literature, there were relatively few studies that scored well (defined as a score > 65%), but these studies tended to provide more consistent information.

Case-Control Studies↗

A pseudoepidemic of Rhodotorula rubra: a marker for microbial contamination of the bronchoscope.

Rhodotorula rubra was isolated from bronchoscopy specimens from 11 patients. An investigation of the bronchoscopy equipment and the bronchoscopy suite revealed contamination of the suction channel with R rubra, as well as potentially pathogenic bacteria. Disinfection control methods included gas sterilization of the bronchoscope and the institution of an alcohol and air flush through the suction channel to allow complete drying of the scope between each patient use. We have had no further isolates of R rubra from bronchoscopy specimens since these measures were instituted, and repeat cultures from the suction channel have been negative.

Adult↗

Use and safety of acellular pertussis vaccine among adult hospital staff during an outbreak of pertussis.

During May and June 1993, 10 patients and 5 members of the clinical staff at a hospital in California were diagnosed with Bordetella pertussis infection. In addition to erythromycin prophylaxis, 630 (48%) of 1330 staff members received a half dose of acellular pertussis vaccine with tetanus and diphtheria toxoids (DTaP). To identify side effects of the vaccine, a questionnaire was completed by 344 (54%) of 630 vaccinated staff. Side effects were reported by 117 respondents (34%); 64 were classified as mild (local reaction at injection site) and 50 as moderate (systemic complaints or local reaction resulting in limitation of arm movement). Three vaccinees (< 1%) reported missing 1 or more days of work because of their symptoms. Local reactions at the injection site occurred in 100 (29%), systemic symptoms in 38 (11%), and limitation of arm movement in 18 (5%). This study indicates that use of half dose of DTaP in adults appears safe and should be considered as an adjunct to chemoprophylaxis during institutional outbreaks.

Adult↗

Validation of self-reported history of acute myocardial infarction: experience of the Minnesota Heart Survey Registry.

Accurate separation of new cases of acute myocardial infarction from prevalent cases is critical for assessing trends in morbidity in population-based studies. This report presents data on the validity of self-reported history of previous acute myocardial infarction among 3,703 patients admitted to a coronary care unit with suspicion of acute myocardial infarction. We substantiated the history of a prior event for 60% of those who reported one (629 of 1,053) and found 40% to be false-positive histories. Much of the false-positive reporting was related to previous cardiac hospitalizations, predominantly (40%) for unstable angina.

Adult↗

Teaching Spanish to emergency medicine residents.

OBJECTIVE: To determine the effects of teaching medical Spanish to eight PGY1 emergency medicine residents on their subsequent interactions with Spanish-speaking patients. METHODS: Eight PGY1 residents completed a 45-hour medical Spanish course administered during their first residency month. Thirty-four subsequent physician-patient interactions by these residents were audiotaped over a six-month period at a suburban teaching ED. The tapes were transcribed and analyzed for errors by a professional medical Spanish interpreter and a native Spanish speaker. RESULTS: Minor errors (e.g., technically incorrect grammar or vocabulary with generally appropriate patient understanding) were found in more than half of the interactions and major errors (e.g., misunderstanding duration of symptoms, misunderstanding of vocabulary) were found in 14% of the interactions. In addition, although the course was designed to supplement, not replace, professional interpreters, the residents called for an interpreter only 46% of the time. CONCLUSION: Although medical language courses may be a useful adjunct to interpreters, they are not designed to replace them. Significant errors may occur when participants in such courses assume their knowledge is sufficient to obtain a good history, give patient release instructions, and provide medical care in general without an interpreter present.

Adolescent↗

Interpersonal team leadership skills.

To say that a team leader's job is a tough one is certainly not saying enough. It is up to the team leader to manage a group of people to be individuals but yet work as a team. The team leader must keep the peace and yet create a revolution with this group all at the same time. The good leader will require a lot of education, training, and tons of practical application to be a success. The good news, however, is that the team leader's job is a rewarding one, one that they'll always feel good about if they do it right. How many of us get the opportunity to take a group of wonderful, thinking individual minds and pull from them ideas that a whole team can take to success? Yes, the job is indeed tough, but the paybacks are many.

Conflict, Psychological↗

Living in space: results from Biosphere 2's initial closure, an early testbed for closed ecological systems on Mars.

The following summary of results from the first 2-year closure experiment (September 26, 1991 to September 26, 1993) in Biosphere 2 is excerpted from a chapter written by William Dempster and myself for a book, Strategies for Mars, edited by Carol Stoker and Carter Emmart of NASA Ames Research Center. The book will be published later this year by Krieger Publishers. It brings together a number of the most striking initial results, including food production and nutrition; ecosystem changes; oxygen and carbon dioxide dynamics; and the human role and response to living in a small, recycling life support system. The references cited are useful as a guide to currently available articles in journals. Hopefully, the next year will see a proliferation of papers presenting more data from the first 2 years of Biosphere 2's operation. There was a wealth of data collected during the closure and by teams of researchers who had access to the facility during the 5-month transition period following the departure of the first crew and the commencement of the second closure experiment in March, 1994.

Agriculture↗

New restriction endonuclease CviRI cleaves DNA at TG/CA sequences.

A new type II restriction endonuclease, CviRI, was isolated from virus XZ-6E infected chlorella cells. CviRI is the first restriction endonuclease to recognize the sequence 5'-TGCA-3' and cleaves DNA between the G and C residues to produce blunt-end termini. Methylation of the adenine or cytosine in 5'-TGCA-3' sequences prevents CviRI cleavage. Due to its sequence specificity, CviRI may be especially useful for detecting mutant alleles of many heritable human genetic diseases.

Animals↗

Testing for antibody to hepatitis A to decrease the cost of hepatitis A prophylaxis with immune globulin or hepatitis A vaccines.

BACKGROUND: The introduction of new vaccines to prevent hepatitis A infection raises the question of the cost of these vaccines relative to immune globulin when short-term protection against hepatitis A is required. Since the prevalence of hepatitis A antibodies (anti-HAV) in the US population increases rapidly with age, testing for anti-HAV may decrease the cost of vaccination programs. METHODS: A cost-analysis model was developed that incorporates the cost of immune globulin or hepatitis A vaccine, the number of doses of vaccine, the cost of testing for anti-HAV in either commercial or public-sector laboratories, and the prevalence of anti-HAV in the general population by age. RESULTS: In comparison with hepatitis A vaccines, with expected costs between $10 and $25 per dose, use of immune globulin for postexposure prophylaxis or preexposure short-term (< or = 6 months) prophylaxis is much less expensive for all age groups. Testing for anti-HAV does not significantly diminish the cost of immune globulin regimens. In contrast, if anti-HAV testing is performed in a public-sector laboratory at $10 per test, and hepatitis A vaccine costs $10 per dose, testing reduces vaccination costs in those 40 years of age or older for a two-dose vaccine regimen and in those 30 years of age or older for a three-dose regimen. At the other end of the spectrum, if vaccine costs $35 per dose, commercial testing for anti-HAV at $25 per person reduces the costs in those 30 years of age or older if either a two- or three-dose regimen is elected. However, vaccine savings are realized in those 10 years and older if public-sector testing is performed and three doses of vaccine at $35 per dose are utilized. In an intermediate scenario of public-sector testing and vaccines costing $25 per dose, the cost would also be reduced in those 30 years old or older. CONCLUSIONS: Testing for anti-HAV in frequent travelers, international government, business, and volunteer workers, military personnel, etc, may be an effective means of decreasing costs of hepatitis A prevention.

Adolescent↗

Atmospheric dynamics and bioregenerative technologies in a soil-based ecological life support system: initial results from Biosphere 2.

Biosphere 2 is the first man-made, soil-based, bioregenerative life support system to be developed and tested. The utilization and amendment of local space resources, e.g. martian soil or lunar regolith, for agricultural and other purposes will be necessary if we are to minimize the requirement for Earth materials in the creation of long-term off-planet bases and habitations. Several of the roles soil plays in Biosphere 2 are 1) for air purification 2) as a key component in created wetland systems to recycle human and animal wastes and 3) as nutrient base for a sustainable agricultural cropping program. Initial results from the Biosphere 2 closure experiment are presented. These include the accelerated cycling rates due to small reservoir sizes, strong diurnal and seasonal fluxes in atmospheric CO2, an unexpected and continuing decline in atmospheric oxygen, overall maintenance of low levels of trace gases, recycling of waste waters through biological regeneration systems, and operation of an agriculture designed to provide diverse and nutritionally adequate diets for the crew members.

Agriculture↗