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Biomedical subjects

G Davis

Publications and source records attributed to G Davis.

At least 55 records · Page 3Linked to original sources
PubMed2000

Consensus and comprehensive linkage maps of bovine chromosome 7.

The objective of this project was to integrate the currently available linkage maps for bovine chromosome 7 (BTA7) by combining data sets from eight research groups. A total of 54 unique markers were typed in eight pedigrees. Multilocus linkage analysis with CRI-MAP produced a bovine chromosome 7 consensus framework map of 27 loci ordered with odds greater than 1000:1. Furthermore, we present a bovine chromosome 7 comprehensive map integrating 54 loci. The locus order is in general agreement with the recently published linkage maps except for one discrepancy. The order of loci BM9289, BMS713, and ILSTS001 was reversed in the consensus framework map relative to the published USDA-MARC bovine chromosome 7 linkage map.

Animals↗
PubMed2000

Long-term renal effects of unilateral ureteral obstruction and the role of endothelin.

BACKGROUND: Angiotensin II (Ang II) and endothelin (ET) are involved in the alteration of renal function in unilateral ureteral obstruction (UUO). The renal response to Ang II following the reversal of a 24-hour UUO and the effect of ET blockade by bosentan during the time of obstruction were investigated. METHODS: Following blockade of the endogenous production of Ang II by captopril, the renal response to Ang II was studied in rats 15 to 18 days after a 24-hour UUO (N = 10) or a sham operation (N = 9) both with (N = 10) and without (N = 8) bosentan treatment in the periobstruction period. Similar studies were performed in another group (N = 9) two months following the reversal of obstruction. RESULTS: In the sham-operated group, Ang II reduced renal blood flow (RBF) by 42 +/- 9% (P < 0.01), glomerular filtration rate (GFR) by 30 +/- 8% (P < 0.01), urine volume (UV) by 44 +/- 9% (P < 0.001), and absolute (UNaV) and fractional sodium excretion (FENa) by 52 +/- 9% (P < 0.001) and 33 +/- 9% (P = 0.054), respectively. In the previously obstructed kidney, Ang II did not change RBF but increased GFR by 106 +/- 40% (P < 0.01), UV by 75 +/- 21% (P < 0.001), UNaV by 190 +/- 60% (P < 0.001), and FENa by 40 +/- 13% (P < 0.05). Bosentan treatment in the obstructed group prevented these Ang II-induced effects and did not have any effect on the sham-operated kidney. Two months following reversal of the obstruction, the response of the kidney was similar to that of the control kidney. CONCLUSION: Twenty-four-hour UUO results in a temporary abnormality in the renal response to Ang II, which is due, in part, to the actions of ET at the time of obstruction.

Angiotensin II↗
PubMed2000

Patients with a prior failed transvaginal cerclage: a comparison of obstetric outcomes with either transabdominal or transvaginal cerclage.

OBJECTIVE: Our purpose was to compare the incidence of preterm birth after a prior failed vaginal cerclage in patients who had a subsequent transabdominal or a transvaginal cerclage. STUDY DESIGN: We conducted a retrospective cohort study of singleton pregnancies in women who had undergone (9-14 weeks) either a transabdominal or a transvaginal prophylactic cerclage after >/=1 prior failed transvaginal cerclage. Prior failed transvaginal cerclage was defined as a preterm birth at <33 weeks' gestation in the immediate prior pregnancy despite a transvaginal cerclage. All transabdominal cerclage procedures were performed by a single attending physician (George Davis, DO). Patients with a cervix too short for transvaginal cerclage placement, placenta previa, or major fetal anomalies were excluded. Primary outcome was preterm birth at <35 weeks' gestation. RESULTS: Forty transabdominal and 24 transvaginal cerclage pregnancies were analyzed. These 2 groups were similar in race and payer status but differed in age (34.0 +/- 4.2 vs 31.3 +/- 4.6 years, respectively; P =.01). The transabdominal cerclage group had more prior failed cerclage procedures per patient (1.8 +/- 1.0 vs 1.1 +/- 0.3; P =.02) and more prior 14- to 24-week spontaneous abortions per patient (2.4 +/- 1.3 vs 1.5 +/- 1.0; P =.02) than the transvaginal cerclage group. Preterm delivery at both <35 and <33 weeks' gestation was less common in the transabdominal cerclage group (18% vs 42%, P =.04; 10% vs 38%, P =.01; respectively) than in the transvaginal cerclage group. Gestational age at delivery was 36. 3 +/- 4.1 weeks in the transabdominal cerclage group and 32.8 +/- 8. 6 weeks in the transvaginal cerclage group (P =.03). Preterm premature rupture of membranes also occurred less often in the transabdominal cerclage group than in the transvaginal cerclage group (8% vs 29%, P =.03). CONCLUSION: In patients with a prior failed transvaginal cerclage, transabdominal cerclage is associated with a lower incidence of preterm delivery and preterm premature rupture of membranes in comparison with transvaginal cerclage.

Abdomen↗
PubMed2000

Intra- and post-operative assessment of renal cortical perfusion by laser Doppler flowmetry in renal transplantation in the rat.

Renal blood flow (RBF) in the period immediately following transplantation has an important prognostic value. Here we report for the first time on the use of laser Doppler flowmetry (LDF) for the measurement of renal cortical perfusion (RCP) during all the important steps in renal transplantation. Left orthotopic kidney transplantation was performed in Lewis rats (n = 14) after 2 h of cold ischaemia and preservation in EuroCollins solution. Under baseline conditions, RCP in the donor and recipient kidneys were similar with a coefficient of variability of 11 and 12%, respectively. There was a progressive increase in RCP during the first 60 min after transplantation with a return to normal values 2 weeks later. In conclusion, LDF provides a rapid and continuous measure of RCP without interference to the operative site and may prove a useful tool for the measurement of RBF during kidney transplantation.

Animals↗
PubMed2000

The role of endothelin in early renal cortical reperfusionin renal transplantation.

The role of specific endothelin receptors in the early renal reperfusion and long-term survival in renal transplantation was investigated in Lewis rats. Left renal transplantation was performed following 2 h cold ischaemia without and with ET(A) receptor antagonism and following 16 h cold ischaemia with no treatment, with ET(A) receptor antagonism and with ET(B) receptor antagonism. The ET(A) and ET(B) receptor antagonists, BQ-610 and A-192621 respectively, were added to the preservation solution. Renal cortical perfusion (RCP) was measured postoperatively using laser Doppler flowmetry. All rats in the 2-hour groups survived for 15 days. Animals in the untreated 16-hour group or in the A-192621-treated group died between days 3 and 6 after surgery. Fifty percent of the rats in the 16-hour and BQ-610-treated group died between days 4 and 7 after surgery while the other 50% survived for 15 days. Survival rates correlated well with both the postoperative serum creatinine and the recovery of RCP. We conclude that addition of an ET(A) receptor antagonist to the preservation solution improves renal reperfusion and long-term survival following prolonged ischaemia, whereas ET(B) receptor antagonism does neither.

Animals↗
PubMed2000

CD45 tyrosine phosphatase inhibitory components from Aspergillus niger.

Two inhibitors of CD45 tyrosine phosphatase, dihydrocarolic acid (1) and penitricin D (2), were isolated from a fermentation broth of the fungus Aspergillus niger and purified by HSCCC (high speed countercurrent chromatography) followed by HPLC. The structures were determined by NMR. The inhibitory activities of both compounds were specific to tyrosine phosphatases.

Aspergillus niger↗
PubMed2000

Self-administered topical imiquimod treatment of vulvar intraepithelial neoplasia. A report of four cases.

BACKGROUND: Vulvar intraepithelial neoplasia (VIN) generally can be classified into viral and nonviral etiologies. The histopathologic diagnosis is often separable into basaloid and warty types. A large percentage of VIN lesions have been shown to harbor human papillomavirus (HPV), principally type 16. Imiquimod, an immune response modifier, has been shown to be safe and effective for the treatment of external and perianal genital warts caused by HPV. CASES: Four cases occurred of clinical and histopathologically diagnosed viral VIN 3. An imiquimod treatment protocol, previously used in a study of this drug for the treatment of external genital warts, was followed. Imiquimod 5% cream was patient applied three times per week until all lesions cleared, for a maximum of 16 weeks. CONCLUSION: Imiquimod may be an effective treatment modality for viral VIN 3 in the future.

Adjuvants, Immunologic↗
PubMed2000

Early metabolic defects for developing diabetes mellitus among offspring of patients with type 2 diabetes are independent of gender.

The aim of the study was to investigate if the female offspring of patients with Type 2 diabetes have more metabolic defects for developing diabetes mellitus than their male counterparts. Thirty-four offspring (10 males, 24 females) of patients with Type 2 diabetes mellitus aged 28.9 +/- 1.5 years (mean +/- SEM) underwent a standard oral glucose tolerance tests (OGTT; 75 g glucose in 300 ml water). Anthropometric indices, plasma lipids and blood pressure were measured while insulin resistance (IR) and sensitivity (%S) were assessed using the Homeostasis Model Assessment (HOMA) method. All the offspring had normal glucose tolerance but high HOMA-derived IR values (27.2 +/- 4.2 vs. 22.5 +/- 2.7 pmol/mmol/l, p > 0.05) and low %S (48.1 +/- 5.1 vs. 50.6 +/- 3.9%, p > 0.05), all of which did not differ on gender comparisons. Multiple linear regression analyses suggest that gender had no influence on the outcome of the result (p = 0.37). Again, body mass index (BMI), fasting serum insulin, plasma glucose, triglyceride, total cholesterol, HDL-cholesterol and LDL-cholesterol were all similar in both genders (p > 0.05). The results suggest that though the offspring manifested metabolic defects for developing diabetes in later life, this susceptibility is independent of gender in the population studied. Further studies with a larger sample size are warranted to confirm these findings in this population.

Adult↗
PubMed1999

Retrograde intubation dacryocystorhinostomy for proximal and midcanalicular obstruction.

OBJECTIVE: Retrograde intubation of canaliculi during dacryocystorhinostomy can restore canalicular patency in cases otherwise managed with bypass tubes. The surgical technique and success for this procedure are discussed. DESIGN: A retrospective, noncomparative case series with clinic or telephone interview for long-term follow-up of patients' symptoms. PARTICIPANTS: One hundred two patients who had undergone this particular lacrimal drainage surgery at Moorfields Eye Hospital between 1992 and 1997. INTERVENTION: All patients underwent a dacryocystorhinostomy and retrograde canaliculostomy while under general anesthetic. MAIN OUTCOME MEASURES: Relief or reduction of epiphora and discharge. RESULTS: One hundred twenty-three lacrimal systems of 102 patients were included. There were 53 females and 49 males, with ages at surgery ranging from 6 to 83 years (mean, 49 years). The etiology was idiopathic (30%), herpetic canaliculitis (24%), punctal agenesis (18%), and trauma (11%); less-common causes included dacryocystitis, Stevens-Johnson syndrome, eczema, and prior radiation therapy. Both upper and lower canalicular systems were involved in the majority (73%) of patients, and in 13 (11%) systems a dacryocystorhinostomy had previously been performed. The silicone tube was placed for a mean of 2 months (range, 1 week-9 months), and the mean postoperative follow-up was 8 months (range, 2-24 months). Epiphora subjectively improved in 90 (73%) of 123 systems, of which 27 (22%) of 123 were asymptomatic. In 33 systems (27%) in which epiphora persisted, 14 (11%) have undergone closed placement of a Jones canalicular bypass tube with control of symptoms. CONCLUSIONS: Retrograde canaliculostomy and intubation can spare a significant number of patients the long-term inconvenience of Jones tubes. Failure of this technique does not, however, compromise or complicate the future placement of a bypass tube.

Adolescent↗
PubMed1999

Longitudinal study of predictive factors for periodontal disease and tooth loss.

Longitudinal assessment of risk factors for periodontal disease is necessary to provide evidence that a putative risk factor or risk indicator is a true risk factor. The purpose of the present study was to explore longitudinally a variety of markers as possible periodontal risk factors in subjects with little or no periodontal disease at baseline. 415 subjects with mild or little periodontal disease were examined: medical and dental history; socioeconomic profile, clinical measurements, microbial samples and radiographic assessment of bone height were performed at baseline, and at a follow-up examination 2 to 5 years later. Mean probing pocket depth (PPD) at baseline was 1.99+/-0.37 mm while mean overall change was 0.1 mm which amounts to an annual rate of 0.04 mm. Overall mean clinical attachment level (1.75+/-0.6 mm) at baseline resulted in mean attachment change of 0.28 mm (0.12 mm annually). Alveolar crestal height (ACH) at baseline (mean 2.05+/-0.85 mm) resulting in a mean net loss of 0.1 mm. Approximately 10% of all sites presented for the second visit with attachment loss exceeding the threshold (4.4% annually), while only 2.2% of all sites exhibited attachment gain (0.88% annually). Older individuals exhibited greater mean bone loss but the least amount of attachment loss. Current smokers exhibited greater disease progression compared to non-smokers. Tooth morbidity (0.17 teeth/patient/year) was associated with greater baseline CAL and ACH loss, and an assortment of systemic conditions. Subjects who harbored Bacteroides forsythus (Bf) at baseline had greater loss in ACH; likewise, these subjects experienced greater proportions of losing sites and twice as much tooth mortality compared to Bf-negative patients. Baseline clinical parameters correlated strongly with the outcome, i.e., subjects with deeper mean pocket depth at baseline exhibited greater increase in pocket depth overtime; while subjects with greater attachment loss at baseline exhibited greater attachment loss between the 1st and 2nd visits.

Adult↗
PubMed1999

An interactive, computer-based program to educate patients about genital herpes.

BACKGROUND AND OBJECTIVES: Education and counseling constitute a substantial portion of management of patients with genital herpes. Innovative methods for education about genital herpes are needed. GOAL: To test the ability of an interactive, computer-based program to educate patients about genital herpes. STUDY DESIGN: Persons seeking care at five urban offices were asked to participate. A knowledge test about genital herpes was administered before and after participation. Participants' satisfaction was assessed with a questionnaire. RESULTS: Four hundred thirty-five participants enrolled, and 428 completed the herpes knowledge test. Of six questions evaluated, a statistically significant increase in the proportion of correct answers was noted on five of six questions. Fifty-one percent of participants answered all the questions correctly after the program, compared with 39% before the program. Satisfaction with the program was very high. CONCLUSIONS: Innovative, computer-based programs can provide education and assist in the management of chronic sexually transmitted infections.

Adolescent↗
PubMed1999

Gibberellin Biosynthesis in Maize. Metabolic Studies with GA(15), GA(24), GA(25), GA(7), and 2,3-Dehydro-GA(9).

[17-(14)C]-Labeled GA(15), GA(24), GA(25), GA(7), and 2,3-dehydro-GA(9) were separately injected into normal, dwarf-1 (d1), and dwarf-5 (d5) seedlings of maize (Zea mays L.). Purified radioactive metabolites from the plant tissues were identified by full-scan gas chromatography-mass spectrometry and Kovats retention index data. The metabolites from GA(15) were GA(44), GA(19), GA(20), GA(113), and GA(15)-15,16-ene (artifact?). GA(24) was metabolized to GA(19), GA(20), and GA(17). The metabolites from GA(25) were GA(17), GA(25) 16alpha,17-H(2)-17-OH, and HO-GA(25) (hydroxyl position not determined). GA(7) was metabolized to GA(30), GA(3), isoGA(3) (artifact?), and trace amounts of GA(7)-diene-diacid (artifact?). 2,3-Dehydro-GA(9) was metabolized to GA(5), GA(7) (trace amounts), 2,3-dehydro-GA(10) (artifact?), GA(31), and GA(62). Our results provide additional in vivo evidence of a metabolic grid in maize (i.e. pathway convergence). The grid connects members of a putative, non-early 3,13-hydroxylation branch pathway to the corresponding members of the previously documented early 13-hydroxylation branch pathway. The inability to detect the sequence GA(12) --> GA(15) --> GA(24) --> GA(9) indicates that the non-early 3,13-hydroxylation pathway probably plays a minor role in the origin of bioactive gibberellins in maize.

Journal Article↗
PubMed1999

Summary report of the TD-3 workshop: characterization of 83 antibodies against prostate-specific antigen.

Twelve research groups participated in the ISOBM TD-3 Workshop in which the reactivity and specificity of 83 antibodies against prostate-specific antigen (PSA) were investigated. Using a variety of techniques including cross-inhibition assays, Western blotting, BIAcore, immunoradiometric assays and immunohistochemistry, the antibodies were categorized into six major groups which formed the basis for mapping onto two- and three-dimensional (2-D and 3-D) models of PSA. The overall findings of the TD-3 Workshop are summarized in this report. In agreement with all participating groups, three main antigenic domains were identified: free PSA-specific epitopes located in or close to amino acids 86-91; discontinuous epitopes specific for PSA without human kallikrein (hK2) cross-reactivity located at or close to amino acids 158-163; and continuous or linear epitopes shared between PSA and hK2 located close to amino acids 3-11. In addition, several minor and partly overlapping domains were also identified. Clearly, the characterization of antibodies from this workshop and the location of their epitopes on the 3-D model of PSA illustrate the importance of selecting appropriate antibody pairs for use in immunoassays. It is hoped that these findings and the epitope nomenclature described in this TD-3 Workshop are used as a standard for future evaluation of anti-PSA antibodies.

Antibodies, Monoclonal↗
PubMed1999

Analysis of monoclonal antibodies to prostate-specific antigen: reactivity with native and recombinant prostate-specific antigen.

Epitope mapping analysis was performed on 53 antibodies submitted to the ISOBM TD-3 PSA Workshop. Western blotting and N-terminal amino acid sequencing, using both native and recombinant human prostate-specific antigen (rPSA), identified four different epitope groups for native PSA. Under reducing conditions native PSA was not recognized by 18/53 antibodies suggesting they reacted with conformation-dependent epitopes. Nine other antibodies reacted with a rPSA polypeptide doublet of 34-35 kD corresponding to different rPSA glycoforms. From sequence mapping studies 22/53 antibodies bound epitopes within amino acid residues 25-85, 3/53 antibodies bound to epitopes within residues 86-220, while 10/53 antibodies bound epitopes within residues 221-261. These results indicate that there are multiple immunogenic epitopes localized on the PSA molecule.

Antibodies, Monoclonal↗
PubMed1999

Urinary incontinence among female soldiers.

A self-administered questionnaire was developed to assess the prevalence of urinary incontinence among active duty female soldiers. The questionnaire also addressed basic demographic information, including height, age, weight, and the subjects' present and past military activities. Adaptive measures that the soldiers commonly used to continue exercising and perform their duties were also explored. Seven hundred thirteen questionnaires were handed out to female soldiers at Fort Lewis (Washington), Fort Benning (Georgia), and Fitzsimons Army Medical Center (Colorado) during preparation for physical fitness tests. Of the 563 soldiers (79%) who returned completed questionnaires, 31% indicated that they commonly experienced urinary incontinence during duty and/or training to the extent that it interfered with job performance, hygiene, or was socially embarrassing. Thus, urinary incontinence is a pervasive problem among female soldiers.

Activities of Daily Living↗
PubMed1999

The female athlete triad: prevalence in military women.

The objective of this study was to define the prevalence of the female athlete triad, i.e., the simultaneous occurrence of disordered eating, amenorrhea, and osteoporosis, in military women. A total of 423 active duty female soldiers participated in a three-part prospective, cross-sectional study. Part 1 entailed completing the Eating Disorder Inventory and a clinical interview with those women "at risk" for an eating disorder. Part 2 consisted of a clinical evaluation and laboratory studies of any woman with menstrual irregularities. Part 3 evaluated the bone mineral density of all women meeting the inclusion criteria for parts 1 and 2 using dual-energy X-ray absorptiometry. Of the 423 active duty women who participated in the study, no subject exhibited the full female athlete triad. Thirty-three women (8%) had an eating disorder and 109 women (26%) were at risk for an eating disorder. Our results suggest that the female athlete triad is not a clinically significant problem for the Army.

Adolescent↗