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Biomedical subjects

H Williamson

Publications and source records attributed to H Williamson.

13 recordsLinked to original sources
PubMed2001

Management of Group A beta-hemolytic streptococcal pharyngitis.

Bacteria are responsible for approximately 5 to 10 percent of pharyngitis cases, with group A beta-hemolytic streptococci being the most common bacterial etiology. A positive rapid antigen detection test may be considered definitive evidence for treatment; a negative test should be followed by a confirmatory throat culture when streptococcal pharyngitis is strongly suspected. Treatment goals include prevention of suppurative and nonsuppurative complications, abatement of clinical signs and symptoms, reduction of bacterial transmission and minimization of antimicrobial adverse effects. Antibiotic selection requires consideration of patients' allergies, bacteriologic and clinical efficacy, frequency of administration, duration of therapy, potential side effects, compliance and cost. Oral penicillin remains the drug of choice in most clinical situations, although the more expensive cephalosporins and, perhaps, amoxicillin-clavulanate potassium provide superior bacteriologic and clinical cure rates. Alternative treatments must be used in patients with penicillin allergy, compliance issues or penicillin treatment failure. Patients who do not respond to initial treatment should be given an antimicrobial that is not inactivated by penicillinase-producing organisms (e.g., amoxicillin-clavulanate potassium, a cephalosporin or a macrolide). Patient education may help to reduce recurrence.

Adult↗
PubMed2001

A survey of general surgeons in rural Missouri: potential for rapid decrease in work force.

General surgeons have an essential role in the rural health care system. This telephone survey of 39 rural general surgeons in Missouri found that more than half were 55 or older. Most reported they practiced a broader scope of surgery than colleagues in urban areas, and half believed that current residency graduates are not prepared for surgical practice in rural areas. One-fifth had sought special training experiences to prepare them for rural practice. On balance, 70 percent of the respondents' practices was general surgery, 13 percent "specialty surgery" and 17 percent primary care. Many reported feeling professionally isolated. One-fourth had literally "returned home" to practice. The results suggest that if present trends continue, the next 10 years will see a substantial reduction in the number of general surgeons in rural Missouri.

Adult↗
PubMed1998

Impact of managed waiting for coronary artery bypass graft surgery on patients' perceived quality of life.

BACKGROUND: Current demand for CABG surgery remains high, often exceeds available resources, and has led to the development of managed waiting lists. This study was designed to determine how being placed on a managed waiting list for > 6 weeks for CABG surgery affected patients' perceived quality of life in a Canadian center. METHODS AND RESULTS: Telephone interviews were carried out in the setting of a large urban hospital in northern Alberta. All participants were identified from 3 waiting lists of adult patients waiting for open heart surgery. A master list of patient statements was compiled to formulate the 47-item Waiting List Impact Questionnaire (WLIQ). A total of 102 patients completed the WLIQ by telephone interview. Patients (87.5%) indicated that their quality of life had deteriorated since being placed on the waiting list. None of the patients perceived an improvement in their quality of life. Frequency data for the WLIQ provided a broad, multidimensional perspective of the experience of waiting for CABG surgery and its impact on perceived quality of life. Negative impact was found in each of 5 main themes: employment and income, physical stress, social support, frustration, and quality of life. CONCLUSIONS: This study indicates that patients perceived a negative impact on their quality of life after being placed on a managed waiting list for CABG surgery. In the allocation of healthcare resources, attention should be paid to the impact of waiting on patients' physical well-being as well as on quality of life.

Adult↗
PubMed1995

A hybrid sigma subunit directs RNA polymerase to a hybrid promoter in Escherichia coli.

Most of the sigma (transcriptional initiation specificity) subunits of RNA polymerase, from a wide range of eubacteria, show strong elements of amino acid sequence similarity. There is evidence that two of the "conserved" regions, 2.4 and 4.2, are involved in recognition of the consensus DNA sequences centred near -10 and -35, respectively, which define promoter sites for the initiation of transcription. Since all the alternative sigma subunits of the above type function by binding to a common core polymerase enzyme in a given bacterium, it can be predicted that a hybrid sigma might be functional, and if so should permit RNA polymerase to initiate only at a correspondingly hybrid promoter. To test these predictions, a hybrid gene encoding the amino-proximal 529 amino acids of the major Escherichia coli sigma protein, sigma 70 (including region 2.4) followed by the last 82 amino acids of the heat-shock sigma protein, sigma 32 (including region 4.2) was constructed and fused to Plac on a plasmid. Major-consensus, heat-shock and hybrid promoters were fused to a chloramphenicol acetyl transferase (CAT) reporter gene on a compatible plasmid. CAT assays showed that, as predicted, a promoter with a "heat-shock" -35 consensus and a "major" -10 consensus sequence (PHM) required Plac-dependent production of the hybrid sigma (sigma 70-32) for activity in vivo. PHM then became a strong promoter. The hybrid sigma gene has potential advantages over its parents for structure-function studies.

Amino Acid Sequence↗
PubMed1995

Investigation of the factor VIII intron 22 repeated region (int22h) and the associated inversion junctions.

A region of intron 22 of the factor VIII gene, which contains factor VIII-associated gene A (F8A), is repeated twice more nearer the Xq telomere. It has been proposed that intrachromosomal homologous recombination occurs between the intron 22 repeat and either of the two extragenic copies, resulting in the recurrent inversions that cause almost half of all cases of severe haemophilia A. We have precisely defined the repeated region as 9.5 kb of DNA which we have termed int22h (intron 22 homologous region). The junctions of the inversions examined were shown to represent precise exchanges between the int22h repeats, thus providing conclusive evidence for homologous recombination. The three copies of int22h were compared along 8 kb of their length, using chemical mismatch analysis, and found to be 99.9% similar. The presence of such long, almost identical inverted repeats near the Xq telomere could account for the high frequency at which the inversions occur.

Base Sequence↗
PubMed1989

Loss of a rural hospital obstetric unit: a case study.

As family and general practitioners who provide a substantial portion of the obstetric care in rural areas quit their obstetric practice, small rural hospital obstetric units are at risk of closing. Using a case study design, we examined the impact of the loss of obstetric services at a small rural hospital in Missouri. This unit was the site of delivery for less than one-half of the infants born to women living within its service area. However, it was the most likely source of care for women who were young, undereducated and unmarried (p less than 0.01). Evidence derived from birth certificates showed that women who delivered there had good perinatal outcomes compared with local women who delivered at larger hospitals. A gradual decline in the number of physicians providing obstetric care preceded the closing of the hospital unit. Women from the hospital service area who presented late for prenatal care were twice as likely to have had a low birthweight infant in the year after the local hospital unit closed (16.7% versus 7.4%), although this difference and other comparisons of outcomes were not statistically significant.

Evaluation Studies as Topic↗
PubMed1983

Melittin induces fusion of unilamellar phospholipid vesicles.

Melittin, the soluble lipophilic peptide of bee venom, causes fusion of phospholipid vesicles when vesicle suspensions are heated or cooled through their thermal phase transition. Fusion was detected using a new photochemical method (Morgan, C.G., Hudson, B. and Wolber, P. (1980) Proc. Natl. Acad. Sci. U.S.A. 77, 26-30) which monitors lipid mixing. Electron microscopy and gel filtration confirmed that most of the lipid formed large vesicular structures. Fluorescence experiments with a water-soluble, membrane-impermeable complex of terbium (Wilschut, J. and Papahadjopoulos, D. (1979) Nature 281, 690-692) demonstrate that these ionic contents are released during fusion. The large structures formed by melittin-induced fusion are impermeable to these ions and are resistant to further fusion. This is in contrast to the behavior observed for the cationic detergent cetyltrimethylammonium bromide (CETAB). The large size of the vesicles formed, the extreme speed of the fusion event and the appearance of electron microscope images of the vesicles prior to fusion suggest that the mechanism of the fusion process includes a preaggregation step.

Bee Venoms↗
PubMed1975

A Review of Commonly Used Intrauterine Contraceptive Devices.

The radiographic appearances of the most commonly used intrauterine contraceptives devices are reviewed, and methods are suggested to determine the extrauterine location of these devices. Complications resulting from the use of these devices are also discussed.

Foreign Bodies↗