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Biomedical subjects

W Butler

Publications and source records attributed to W Butler.

At least 19 recordsLinked to original sources
PubMed2001

Evidence of probable scurvy in subadults from archeological sites in North America.

The authors surveyed subadult human skeletons from Native American archeological sites in the United States for evidence of skeletal lesions associated with scurvy. Geographic regions surveyed include the Midatlantic area, the Southeast (Florida), the Southwest, and the Plains. The prevalence of probable subadult scurvy ranged from zero in the Plains samples to 38% in a small sample from Florida. These data indicate the likelihood that scurvy was a significant childhood disease in many Native American groups. Reasons for variation in prevalence remain speculative but include regional and seasonal variation in food types and abundance, cultural patterns of storage and utilization, periodic food shortages, and the relative importance of corn in the diet. These factors are part of a nutritional complex that is related to disease prevalence which can be studied through evidence seen in archeological human remains.

Adolescent↗
PubMed2001

Tobacco hypersensitivity and environmental tobacco smoke exposure in a pediatric population.

BACKGROUND: Skin testing and RAST have verified the existence of tobacco-specific IgE. However, published studies report conflicting results concerning the clinical significance of tobacco IgE. Previous studies have not focused on the role of environmental tobacco smoke (ETS) as it relates to tobacco hypersensitivity (TH) in nonsmoking children. OBJECTIVE: We used nonsmoking pediatric patients to investigate the relationship between ETS and TH. METHODS: Children, ages 4 to 10 years, were prospectively enrolled. ETS exposure and smoke-triggered symptoms were recorded by questionnaire and physician history. Patients were given a skin test (ST) with a panel of aeroallergens plus tobacco extract. A ST reaction to at least one aeroallergen classified a patient as atopic; a ST reaction to tobacco classified a patient as TH. RESULTS: We enrolled 170 patients, mean age 7.2 years. We found 58 (34%) patients reported routine exposure to ETS and 78 (46%) patients reported ETS-induced symptoms. We found 121 (71%) atopic patients and 61 (36%) TH patients. TH was more common in atopic patients (P < .0001) and those routinely exposed to ETS (P < .05). However, TH failed to predict ETS-induced symptoms in either atopic or non-atopic patients (PPV = 0.40, NPV = 0.69). CONCLUSIONS: We evaluated the clinical significance of TH in a nonsmoking patient population related to ETS exposure. We concluded that although TH is statistically related to atopy and ETS exposure, the low predictive values of skin testing for TH limit its clinical usefulness.

Asthma↗
PubMed2000

American brachytherapy society recommendations for clinical implementation of NIST-1999 standards for (103)palladium brachytherapy. The clinical research committee of the American Brachytherapy Society.

PURPOSE: Recent important developments in palladium-103 ((103)Pd) dosimetry mandate a reevaluation of (103)Pd brachytherapy prescribing practices. METHODS AND MATERIALS: The clinical research committee of the American Brachytherapy Society (ABS) convened a consensus session of brachytherapists and physicists to develop recommendations regarding future dose prescribing guidelines for National Institute of Standards and Technology (NIST-1999) calibrated (103)Pd sources. RESULTS: The ABS recommends that clinicians attempt to reproduce the implant doses delivered and reported in the literature through the past decade. CONCLUSIONS: The following should be immediately implemented for (103)Pd dosimetry: 1) All practicing physicians, physicists, dosimetrists, and suppliers implement NIST-1999 air-kerma strength standard for (103)Pd brachytherapy. 2) All treatment planning systems and dose calculation algorithms must be updated to reflect new dose rate constants. The AAPM-recommended validated value for Theraseed model 200 is 0.665 cGy h(-1) U(-1). The dose rate constant for the Mentor MED3633 seed is currently reported as 0.68 cGy h(-1) U(-1). This latter value and the values for seeds from other manufacturers are awaiting independent confirmation. 3) Physicians who previously prescribed 115 Gy for (103)Pd monotherapy prostate implants should now prescribe 125 Gy. When using (103)Pd as a boost following 45 Gy of external beam irradiation, 100 Gy should be prescribed instead of the previous 90 Gy. It is critical that all three changes be implemented concurrently, because they are interdependent.

Brachytherapy↗
PubMed2000

Identification of bacteria from a non-healing diabetic foot wound by 16 S rDNA sequencing.

Approximately 10-20% of diabetic foot wounds fail initial antibiotic treatment. It is generally believed that several bacterial species may be present in these types of wounds. Because some of these organisms cannot be easily cultured, proper identification is problematic and thus, appropriate treatment modalities cannot be applied. This report examined the bacterial flora present in a chronic diabetic foot wound that failed antibiotic treatment. A tissue sample was collected from the base of the wound and used for standard microbiological culturing. DNA from the sample was used to amplify bacterial 16 S rDNA gene sequences and a library of these sequences was made. The clones were placed into two major groups on the basis of their melting temperatures. Representatives of these groups were sequenced, and information was used to identify the bacteria present in the wound. The culture-based method identified a single anaerobic species, Bacteroides fragilis. The method employing rDNA sequencing identified B. fragilis as a dominant organism and Pseudomonas (Janthinobacterium) mephitica as a minor component. The results indicate that rDNA sequencing approach can be an important tool in the identification of bacteria from wounds.

Aged↗
PubMed2000

An analysis of the possibility for health implications of joint actions and interactions between food additives.

The possibility that structurally unrelated food additives could show either joint actions or interactions has been assessed based on their potential to share common sites and mechanisms of action or common pathways of elimination. All food additives approved in the European Union and allocated numerical acceptable daily intake values were studied, initially based on the reports by the FAO-WHO Joint Expert Committee for Food Additives. Target organs were identified based on the effects reported at doses above the no-observed-adverse-effect level (NOAEL) in animal and human studies. The descriptions of the pathological and other changes reported were used to assess whether different additives, sharing the same target organ, would produce a common toxic effect. In all but a very few cases, the possibility of joint actions or interactions could be excluded on scientific grounds. The exceptions were on the liver (curcumin, thiabendazole, propyl gallate, and BHT), the kidney (diphenyl, o-phenylphenol, and ferrocyanide salts), the blood (azorubine and propyl gallate), and the thyroid (erythosine, thiabendazole, and nitrate). Toxicokinetic interactions were considered unlikely because of the low dosages involved, the diverse nature of the routes of metabolism and elimination, and the fact that enzyme induction or inhibition would have influenced selection of the NOAEL. Many of those additives which could not be excluded from showing joint actions or interactions would have low intakes; in some cases they were alternatives for the same application, thereby further lowering the combined intake. In consequence, joint actions or interactions between additives do not represent a significant health concern.

Drug Interactions↗
PubMed1998

Towards new paradigms for the treatment of hypobaric decompression sickness.

Altitude induced (hypobaric) decompression sickness (DCS) has long been treated with ground level oxygen and U.S. Navy Treatment Tables 5 and 6. These treatment tables originate from surface excursion diving and, when implemented, require significant resource allocation. Although they are effective treatment regimens, these tables were not developed for treating hypobaric DCS which has an etiology similar to saturation diving DCS. In this review, different treatment options for hypobaric DCS are presented. These options include more aggressive use of ground level oxygen and treatment tables using a maximum pressure of 2 atmospheres (ATA). Specific attention is given to USAF Table VIII, an experimental hypobaric DCS treatment-table, and space suit overpressurization treatment. This paradigm shift for DCS treatment is based on a projected increase in hypobaric DCS treatment from exposure to low pressure during several operational conditions: cruise flight in the next generation aircraft (e.g., F-22); high altitude, unpressurized flight by special operations forces; and the extraordinary amount of extravehicular activity (EVA) required to construct the international space station. Anticipating the need to treat DCS encountered during these and other activities, it is proposed that 2 ATA or less hyperbaric oxygen (HBO) treatment conjoined with new collapsible chamber technology can be used to address these issues in a safe and cost effective fashion.

Aerospace Medicine↗
PubMed1996

Subdermal contraceptive implant (Norplant) continuation rates among adolescents and adults in a family planning clinic.

STUDY OBJECTIVE: The purpose of this study was to prospectively evaluate the continuation rate of subdermal contraceptive implants (Norplant) among adolescent (< 20 years) and adult (> or = 20 years) women in the clinic population of a tertiary care medical center. DESIGN: Adolescents and adults desiring contraception for greater than a 6-month period were eligible for Norplant insertion. Prior to insertion, personal counseling and extensive education were provided. Following insertion, rapid access, personal counseling, and prompt treatment were provided for complications that occurred. Device removal was available to all individuals at any time upon patient request or if side effects could not be ameliorated. Patient demographic, historical, physical, and follow-up data were entered into a computer data base. RESULTS: Since February 1991, 1800 subdermal contraceptive implants were inserted. Of these 1688 patients were prospectively followed, providing 45,576 women-months of data for analysis. Adolescents comprised 40% of the study population. Over a 50-month period, the cumulative continuation rate for adolescents was 93.6%, and for adults it was 91.1%. The mean duration of use among adolescents was 26.5 months and for adults was 27.6 months. CONCLUSIONS: There was no significant difference between adolescent and adult subdermal contraceptive implant continuation rates for up to 50 months of use. In this patient population, high continuation rates may result from a combination of extensive patient education and intensive surveillance by a well-trained and dedicated multidisciplinary staff. When all patients are enrolled in a program that provides aggressive education and supportive follow-up, age is not a significant factor in continuation rates.

Adolescent↗
PubMed1996

The Department of Defense blood lead level survey program for young children.

Blood lead testing has been conducted in a large group of children who receive their health care from the Department of Defense. The blood lead levels were comparable to levels detected in civilian suburban settings. Among the 90,976 children who were tested, the incidence of children with blood lead levels > or = 10 micrograms/dl was 2.13%.

Chi-Square Distribution↗
PubMed1994

Multiple recurrent benign schwannomas of deep and superficial nerves of the upper extremity: a new variant of segmental neurofibromatosis.

Benign schwannomas of the brachial plexus are uncommon tumors, first described in the late 19th century. These lesions, which are histologically benign, can generally be excised without sacrifice of neural elements. We present the first known case of multiple concurrent and recurrent benign schwannomas of the upper extremity in an individual who demonstrated no other evidence of neurofibromatosis, and we suggest that this case may represent a new subtype of type V neurofibromatosis.

Adult↗
PubMed1988

Are monocular arrays discriminable from binocular arrays?

On each trial of this experiment, a subject was visually stimulated by one or two shadows on a translucent background in a Telebinocular. For each subject, there were 40 trials of monocular stimulation by one shadow, 40 trials of monocular stimulation by two shadows (one in each hemifield), and 40 trials of binocular stimulation by two shadows (one in the left hemifield of one eye and another in the right hemifield of the other eye). Across these randomly ordered trials, 52 subjects were unable to discriminate two right-eye shadows from two left-eye shadows and were unable to discriminate two monocularly perceived shadows from two binocularly perceived shadows. Generally, subjects tended to misidentify right-hemifield shadows as right-eye shadows and tended to misidentify two-hemifield shadows as two-eye shadows.

Attention↗
PubMed1985

Fucokinase, its anomeric specificity and mechanism of phosphate group transfer.

Fucokinase phosphorylates L-fucose at the anomeric position and, as such, might use either the alpha or beta anomer as its substrate. Examination of the utilization of radiolabelled alpha and alpha,beta mixtures established beta-L-fucose as the required substrate. Phosphorylation at the anomeric center might involve either the loss or retention of the anomeric oxygen. The mechanism has been shown to involve anomeric oxygen retention through mass spectrometric analysis of the product phosphate derived from 18O-labelled L-fucose.

Fucose↗
PubMed1985

GM allotypes in Native Americans: evidence for three distinct migrations across the Bering land bridge.

We report the results of typings, for immunoglobulin G allotypes, of 5392 Native Americans from ten samples, the typings having been performed over the last 20 years. Four cultural groups are represented: the Pimans-Pima and Papago; the Puebloans-Zuni and Hopi; the Pai-Walapai; and the Athabascans-Apache and Navajo. The haplotype Gm1;21 has the highest frequency in each population while Gm1,2;21 is polymorphic in all except the Hopi. The Mongoloid marker Gm1;11,13 is found primarily in the Athabascans. The Caucasian haplotype Gm3;5,11,13 is found at polymorphic frequencies in several of the populations but its frequency is very low or absent among nonadmixed individuals. Although Nei's standard genetic distance analysis demonstrates genetic similarity at the Gm and Km loci, the heterogeneity that does exist is consistent both with what is known about the prehistory of Native Americans and traditional cultural categories. When the current Gm distributions are analyzed with respect to the three-migration hypothesis, there are three distinct Gm distributions for the postulated migrants: Gm1;21 and Gm1,2;21 for the Paleo-Indians 16,000 to 40,000 years ago; Gm1;21, Gm1,2;21, and Gm1;11,13 for the second wave of Na-Dene hunters 12,000 to 14,000 years ago; and Gm1;21 and Gm1;11,13 for the Eskimo-Aleut migration 9,000 years ago. The Pimans, Puebloans, and the Pai are descendents of the Paleo-Indians while the Apache and Navajo are the contemporary populations related to the Na-Dene. Finally, the Gm distribution in Amerindians is found to be consistent with a hypothesis of one migration of Paleo-Indians to South American, while the most likely homeland for the three ancestral populations is found to be in northeastern Asia.

Chromosome Mapping↗
PubMed1985

Describing the severity of mottling in a community: a different approach.

Dean's community mottling index, though a useful summary measure, suffers from the use of arbitrary scores and the inability to describe the frequency in each of the levels of mottling. An alternative statistical approach, based on the proportional odds model, is used here to describe the severity of mottling in a community. The use of this model is demonstrated on prevalence data collected on 16 Texas communities.

Fluorides↗