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Biomedical subjects

D Hubbard

Publications and source records attributed to D Hubbard.

17 recordsLinked to original sources
PubMed2002

In vitro activity of levofloxacin against contemporary clinical isolates of Legionella pneumophila, Mycoplasma pneumoniae and Chlamydia pneumoniae from North America and Europe.

OBJECTIVE: To assess the activities of levofloxacin and the comparator agents erythromycin, clarithromycin, azithromycin and doxycycline against atypical respiratory pathogens. METHODS: One hundred and forty-six Legionella pneumophila, 41 Mycoplasma pneumoniae and nine Chlamydia pneumoniae isolates were procured from various culture collections in North America and Europe and tested for susceptibility to the above agents by broth microdilution. The isolates came primarily from clinical sources and were collected from patients between 1995 and 1999. RESULTS: Against L. pneumophila, levofloxacin was the most active agent, with an MIC(90) of 0.03 mg/L, twofold more active than clarithromycin (0.06 mg/L), 16-fold more active than erythromycin and azithromycin (0.5 mg/L) and 64-fold more active than doxycycline. Against M. pneumoniae, azithromycin (MIC(90) < or = 0.0005 mg/L) was the most active agent. However, two isolates of M. pneumoniae, one from the USA and one from Finland, were macrolide resistant (MIC > or = 4 mg/L), but levofloxacin susceptible (MIC 0.25 mg/L). The geographic origin of L. pneumophila and M. pneumoniae did not affect the MIC range for any antimicrobial agent tested. Against C. pneumoniae, clarithromycin was the most active agent, with an MIC range of < or =0.008-0.03 mg/L. CONCLUSIONS: Levofloxacin had comparable activity to the other agents tested against the atypical respiratory pathogens, confirming its potential as an alternative for empirical therapy of community-acquired pneumonia.

Anti-Bacterial Agents↗
PubMed1998

Accuracy of clinical evaluation in pediatric obstructive sleep apnea.

Eighty-two children underwent polysomnography (PSG) for symptoms suggestive of obstructive sleep apnea (OSA). Symptoms reported included snoring, witnessed apneic episodes, daytime somnolence, mouth breathing, and enuresis. Tonsillar size, nasal airway patency, and percentile weight were recorded. OSA was diagnosed on PSG when obstructive events were noted and apnea + hypopnea index was five or more per hour. The overall predictive accuracy of clinical suspicion of OSA was 25 (30%) of 82. Predictive accuracies (as a percentage of those with symptoms/signs who have OSA) and prevalences (as a percentage of those with OSA who have the symptom/sign), respectively, were for moderate snoring 29% (12 of 41), 48%; loud snoring 31% (11 of 35), 44%; witnessed apneas 32% (22 of 69), 88%; enuresis 46% (11 of 24), 44%; 2+ tonsillar size 37% (21 of 57), 84%; 3+ tonsillar size 33% (3 of 9), 12%; 90th percentile weight or greater 26% (7 of 27), 28%; 10th percentile weight or less 33% (5 of 15), 20%. Multiple regression analysis did not reveal a significant association between clinical parameters and the presence of OSA as defined by PSG.

Adolescent↗
PubMed1997

Interrater reliability in myofascial trigger point examination.

The myofascial trigger point (MTrP) is the hallmark physical finding of the myofascial pain syndrome (MPS). The MTrP itself is characterized by distinctive physical features that include a tender point in a taut band of muscle, a local twitch response (LTR) to mechanical stimulation, a pain referral pattern characteristic of trigger points of specific areas in each muscle, and the reproduction of the patient's usual pain. No prior study has demonstrated that these physical features are reproducible among different examiners, thereby establishing the reliability of the physical examination in the diagnosis of the MPS. This paper reports an initial attempt to establish the interrater reliability of the trigger point examination that failed, and a second study by the same examiners that included a training period and that successfully established interrater reliability in the diagnosis of the MTrP. The study also showed that the interrater reliability of different features varies, the LTR being the most difficult, and that the interrater reliability of the identification of MTrP features among different muscles also varies.

Adult↗
PubMed1996

The nematode Caenorhabditis elegans is up to 39 times more sensitive to gamma radiation generated from 137Cs than from 60Co.

Survival after gamma irradiation (generated from either a 137Cs or 60Co source) was determined for two strains of the nematode Caenorhabditis elegans. Animals were between 1.3 and 39 times more sensitive to cesium than to cobalt. The magnitude of this differential sensitivity was dependent upon the strain, developmental stage and sex tested. Several control experiments eliminated trivial explanations for this difference. Since cobalt- and cesium-generated gamma particles have nearly identical energy depositions, the differential sensitivity likely reflects different mechanisms of processing the slightly different spectra of DNA damage induced by these two radiations. Sex-specific differences in radiation sensitivity were also noted and were likely due to the fact that males possess a single X chromosome rather than two, as do hermaphrodites.

Animals↗
PubMed1996

Urologic manifestations of postpolio syndrome.

To determine the character and prevalence of bladder dysfunction among persons with a history of polio, we conducted a survey of randomly selected polio survivors. The survey solicited information on the acute episode of polio and the nature of late-onset neurologic symptoms that could be attributed to postpolio syndrome. There were 242 female and 88 male respondents to the study. Symptoms attributable to postpolio syndrome were present in 87.2% of female subjects and 73.9% of male subjects. Respondents with postpolio syndrome had a significantly greater prevalence of urologic symptoms than seen among respondents without postpolio syndrome, although no dominant pattern of voiding dysfunction was noted. The early onset of erectile dysfunction was more common among male subjects with postpolio syndrome than among male subjects without postpolio syndrome. Genuine stress incontinence was seen in 36.3% of the survey population. Sixteen women with postpolio syndrome underwent surgical repair for urinary incontinence, with a success rate of 60.5%. Bladder disorders are common among persons with PPS, but further clinical and urodynamic data are necessary to define the nature and magnitude of this dysfunction.

Adult↗
PubMed1995

High sun protection factor sunscreens in the suppression of actinic neoplasia.

BACKGROUND AND DESIGN: A controlled trial was undertaken from December 1987 to December 1990 to test the hypothesis that a strong sunscreen can reduce the number of cancerous and precancerous skin lesions. Candidates were selected from a high-risk population attending either a university- or Veterans Affairs-based dermatology practice in Lubbock, Tex, for a prospective, double-blind, controlled trial of daily application of sunscreen vs placebo over a 2-year period. Participants were asked to volunteer if they had demonstrated premalignant changes (actinic keratoses) or nonmelanoma skin cancer (basal cell carcinoma or squamous cell carcinoma), had continuing sun exposure, and were not using sunscreen on a regular basis. Fifty-three volunteers were initially enrolled in the study, and 37 came for the final 24-month visit. RESULTS: The rate of appearance of new precancerous skin lesions was less for the treatment group than for control subjects. People with darker skin had fewer actinic keratoses, women had fewer lesions than men, and people with fewer lesions at enrollment had fewer lesions during the study. The numbers of new nonmelanoma skin cancers appearing during the study period were too small for statistical analysis. CONCLUSIONS: The regular use of sunscreens can significantly reduce cutaneous neoplasia, as indicated by its suppression of precancerous lesions. A longer and/or larger study would be necessary to demonstrate an effect on malignant lesions.

Adult↗
PubMed1994

An ethical framework for operating room infection control.

The operating room nurse has an ethical obligation to provide patients with safe, effective care during surgical intervention. Most basic to this care is surgical asepsis. Bioethics principles of autonomy, beneficence, nonmaleficence, justice, as well as the professional's character in meeting the responsibilities of competence and accountability, are presented as an ethical framework for surgical infection control.

Ethics, Nursing↗
PubMed1991

Cultured human atherosclerotic plaque smooth muscle cells retain transforming potential and display enhanced expression of the myc protooncogene.

The proliferation of vascular smooth muscle cells (SMC) is critical to atherosclerotic plaque formation. The monoclonal hypothesis proposes that the stimulus for this SMC proliferation is a mutational event. Here we describe a procedure for growing human plaque smooth muscle cells (p-SMC) in culture. We show that p-SMCs derived from two patients differ from SMC cultured from normal vascular tissue in expression of the protooncogene myc. One p-SMC strain was extensively characterized; these diploid, karyotypically normal cells have a finite life span in culture. Ultrastructural examination revealed two populations, one with classic contractile SMC appearance, the other, modulated to a synthetic state. Northern blotting showed a 2- to 6-fold and a 6- to 11-fold enhanced expression of myc by p-SMC, compared to SMC derived from healthy human aorta (HA-SMC) and saphenous vein (HV-SMC), respectively. In contrast, the p-SMC and HV-SMC expressed similar levels of message for the genes N-myc, L-myc, Ha-ras, fos, sis, myb, LDL receptor, EGF receptor, IGF I receptor, IGF II, and HMG CoA reductase. Finally, although p-SMCs are not tumorigenic, DNA isolated from these cells is positive in the transfection-nude mouse tumor assay. Myc, however, does not appear to be the transforming gene because no newly introduced human myc gene was detected in the p-SMC-associated nude mouse tumor. Thus human atherosclerotic p-SMCs possess both an activated myc gene and a transforming gene that is retained throughout many cell passages.

Animals↗
PubMed1990

Cultured cell lines from human breast cancer biopsies and xenografts.

Eighty-five breast cancer specimens were processed as part of a program in tumor acquisition, propagation, and preservation for biotherapy. Nine long-term culture cell lines were developed. Four cell lines were from solid tumor metastases, two lines were from pleural fluid specimens, and three were from xenograft tumors grown in nude mice. Two of the xenograft-derived cell lines were from biopsies which produced tumor cell lines as well. Success in establishing cultures did not correlate with the viability of the biopsy received. Poor tumor cell attachment to culture plastic was the most common problem. For certain specimens, attachment and growth were enhanced on collagen and extracellular matrix substrates. Collagen was beneficial in the development of one cell line. The cell lines were characterized and each of the lines contained more nuclear DNA than found in normal cells. Four of five lines tested were tumorigenic in nude mice. Five of nine were clonogenic in soft agar. Each of the cell lines tested reacted with at least two anti-tumor monoclonal antibodies. Xenograft and biopsy-derived cell lines from the same tumor were similar in their characteristics. While breast cancers are indeed difficult to establish and propagate in culture, the use of xenografts and special substrates appears to be beneficial in the development of cell lines from some tumors.

Animals↗
PubMed1989

Tumor acquisition, propagation, and preservation. The culture of human colorectal cancer.

Fourteen new colorectal cancer cell lines were developed as part of a tumor acquisition, propagation, and preservation program for biotherapy. Fifty-six specimens were received. Nine cell lines were generated from biopsies; seven of these cell lines were from metastatic lesions. Five additional cell lines were developed from xenografts grown in nude mice. Biopsies that produced three of these xenografts gave rise to parallel culture cell lines. Biopsy-derived and xenograft-derived cell lines from the same tumor behaved similarly in culture and exhibited similar markers when assessed immunohistochemically. Collagen substrate was beneficial in the primary culture of 50% of the specimens tested. Collagen was required for the successful propagation of two cell lines.

Animals↗
PubMedDate not supplied

Refining a tool to measure cues to action in encouraging health-promoting behavior--the CHAQ.

A convenience sample of 99 questionnaire respondents was used to develop an instrument to measure "cues to action" for health-promoting behaviors. The questionnaire contained 32 items producing an alpha coefficient of 0.88. Because of the small sample size and limitations of the convenience sample, the authors recommend that their findings be considered preliminary.

Adult↗
PubMedDate not supplied

Gender differences in attrition from orthopaedic surgery residency.

We conducted a national survey of orthopaedic surgery residency program directors regarding resident attrition. Female residents had a statistically higher attrition rate than male residents (p < 0.001). The female early withdrawal residents left voluntarily and for personal reasons more often than their male counterparts. These tendencies, however, were not statistically significant. We feel that more in-depth counseling of female medical students and increased mentoring for women in orthopaedic residency could help prevent this attrition.

Career Choice↗