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Biomedical subjects

J A Wilde

Publications and source records attributed to J A Wilde.

At least 19 recordsLinked to original sources

Effectiveness of influenza vaccine in health care professionals: a randomized trial.

CONTEXT: Data are limited and conflicting regarding the effectiveness of influenza vaccine in health care professionals. OBJECTIVE: To determine the effectiveness of trivalent influenza vaccine in reducing infection, illness, and absence from work in young, healthy health care professionals. DESIGN: Randomized, prospective, double-blind, controlled trial over 3 consecutive years, from 1992-1993 to 1994-1995. SETTING: Two large teaching hospitals in Baltimore, Md. PARTICIPANTS: Two hundred sixty-four hospital-based health care professionals without chronic medical problems were recruited; 49 participated for 2 seasons; 24 participated for 3 seasons. The mean age was 28.4 years, 75% were resident physicians, and 57% were women. INTERVENTION: Participants were randomly assigned to receive either an influenza vaccine or a control (meningococcal vaccine, pneumococcal vaccine, or placebo). Serum samples for antibody assays were collected at the time of vaccination, 1 month after vaccination, and at the end of the influenza season. Active weekly surveillance for illness was conducted during each influenza epidemic period. MAIN OUTCOME MEASURES: Serologically defined influenza infection (4-fold increase in hemagglutination-inhibiting antibodies), days of febrile respiratory illness, and days absent from work. RESULTS: We conducted 359 person-winters of serologic surveillance (99.4% follow-up) and 4746 person-weeks of illness surveillance (100% follow-up). Twenty-four(13.4%) of 179 control subjects and 3 (1.7%) of 180 influenza vaccine recipients had serologic evidence of influenza type A or B infection during the study period. Vaccine efficacy against serologically defined infection was 88% for influenza A (95% confidence interval [CI], 47%-97%; P=.001) and 89% for influenza B (95% CI, 14%-99%; P=.03). Among influenza vaccinees, cumulative days of reported febrile respiratory illness were 28.7 per 100 subjects compared with 40.6 per 100 subjects in controls (P=.57) and days of absence were 9.9 per 100 subjects vs 21.1 per 100 subjects in controls (P=.41). CONCLUSIONS: Influenza vaccine is effective in preventing infection by influenza A and B in health care professionals and may reduce reported days of work absence and febrile respiratory illness. These data support a policy of annual influenza vaccination of health care professionals.

Absenteeism

Medically unnecessary pediatric ambulance transports: a medical taxi service?

OBJECTIVE: To characterize ambulance utilization in a pediatric population and pediatric emergency physicians' judgement of the medical need for ambulance transport. METHODS: A convenience sample of ambulance transports were studied prospectively during a 5-week period. Exclusion criteria included transfer from another medical facility, study physician not available, need for immediate resuscitation, or trauma team activation. A questionnaire completed by the physician assessed medical need for the ambulance based on chief complaint, general appearance, vital signs, and ambulance run sheet information. A separate questionnaire was administered to the parents regarding reasons for ambulance use and other available means of transportation. Caregivers were contacted by telephone 2-3 days later to determine the mode of transportation home and the clinical outcome. RESULTS: Of 172 eligible patients, 92 (53%) were enrolled. Most (61%; 56/92) transports were considered medically unnecessary. Interestingly, 40% (37/92) of the subjects had no other means of transportation; 86% (32/37) of ambulance transports for this group were judged medically unnecessary. Overall, 86% (79/92) of families had not called their physician. There was no association between having spoken with the physician and medical need for an ambulance. Many (82%; 46/56) Medicaid transports were judged medically unnecessary Overall, follow-up was achieved for 91% (85/92) of the patients. No patient for whom transport was medically unnecessary had a repeat ED visit for the same complaint or required admission. Most patients (74%; 68/92) returned home without any assistance. Among the medically unnecessary transports, 52% (32/60) of the caregivers cited no other means of transportation, yet 34% (11/32) of these patients returned home by private car. CONCLUSIONS: Most pediatric ambulance transports in this sample, which excluded patients requiring immediate resuscitation or trauma team care, were judged to be medically unnecessary. Caregivers often use an ambulance as a convenience or as the only means of transportation. An alternate, less resource-intensive transportation system may be more appropriate for this population.

Adolescent

Characterization of conformational features of DNA heteroduplexes containing aldehydic abasic sites.

The DNA duplexes shown below, with D indicating deoxyribose aldehyde absic sites and numbering from 5' to 3', have been investigated by NMR. The 31P and 31P-1H correlation data indicate [formula: see text] that the backbones of these duplex DNAs are regular. One- and two-dimensional 1H NMR data indicate that the duplexes are right-handed and B-form. Conformational changes due to the presence of the abasic site extend to the two base pairs adjacent to the lesion site with the local conformation of the DNA being dependent on whether the abasic site is in the alpha or beta configuration. The aromatic base of residue A17 in the position opposite the abasic site is predominantly stacked in the helix as is G17 in the analogous sample. Imino lifetimes of the AT base pairs are much longer in samples with an abasic site than in those containing a Watson-Crick base pair. The conformational and dynamical properties of the duplex DNAs containing the naturally occurring aldehyde abasic site are different from those of duplex DNAs containing a variety of analogues of the abasic site.

Aldehydes

Identification of residues involved in a conformational change accompanying substitutions for glutamate-43 in staphylococcal nuclease.

A recent paper from our laboratories [Hibler, D. W., Stolowich, N. J., Reynolds, M. A., Gerlt, J. A. Wilde, J. A., & Bolton, P. H. (1987) Biochemistry 26, 6278] described the generation of site-directed substitutions for the putative general base Glu-43 in the active site of Staphylococcal nuclease (SNase) and the use of 1H NMR spectroscopy to characterize the effect of the substitutions on the conformations of the mutant proteins. The replacements for Glu-43 (Asp, Gln, Asn, Ser, and Ala) both decreased the catalytic efficiency and changed the one- and two-dimensional NMR spectral properties of the mutant enzymes. We have prepared and studied the NMR spectral properties of several samples of deuteriated wild-type SNase that allow sequence-specific resonance assignments for several aromatic and aliphatic amino acid side chains that experience changes both in normal one-dimensional spectra and in two-dimensional NOESY spectra. Due to severe spectral congestion of resonances in the one- and two-dimensional spectra of protiated SNase, the assignments would have been difficult, if not impossible, to obtain without deuteriation of selected amino acids. The spectra we have obtained demonstrate that changes in NOE intensities involve a valine residue that is spatially adjacent to two phenylalanine residues; given the X-ray structure for SNase [Cotton, F. A., Hazen, E. E., & Legg, M. J. (1979) Proc. Natl. Acad. Sci. U.S.A. 76, 2551], these residues must be Val-74, Phe-34, and Phe-76. In addition, a leucine residue experiencing changes in NOE intensities spatially adjacent to Val-74 and Phe-34 can be assigned to Leu-25.(ABSTRACT TRUNCATED AT 250 WORDS)

Binding Sites