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Biomedical subjects

T Quinn

Publications and source records attributed to T Quinn.

At least 19 recordsLinked to original sources
PubMed2003

Effect of standard vs extended Roux limb length on weight loss outcomes after laparoscopic Roux-en-Y gastric bypass.

BACKGROUND: Increasing the length of the Roux limb in open Roux-en-Y gastric bypass (RYGB) effectively increases excess weight loss in superobese patients with a body mass index (BMI) >50 kg/m2. Extending the RYGB limb length for obese patients with a BMI < 50 could produce similar results. The purpose of this study was to compare the outcomes of superobese patients undergoing laparoscopic RYGB with standard (< or =100-cm) with those undergoing the procedure with an extended (150-cm) Roux limb length over 1-year period of follow-up. METHODS: Retrospective data over 2.5 years were reviewed to identify patients with a BMI < 50 who underwent primary laparoscopic RYGB with 1-year follow-up ( n = 58). Forty-five patients (sRYGB group) received limb lengths < or = 100 cm, including 45 cm ( n = 1), 50 cm ( n = 2), 60 cm ( n = 6), 65 cm ( n = 1), 70 cm ( n = 1), 75 cm ( n = 3), and 100 cm ( n = 31). Thirteen patients (eRYGB group) received 150-cm limbs. Postoperative weight loss was compared at 3 weeks, 3 months, 6 months, and 1 year. RESULTS: Comparing the sRYGB vs the eRYGB group (average +/- SD), respectively: There were no significant differences in age (41.5 +/- 11.0 vs 38.0 +/- 11.9 years), preoperative weight (119.2 +/- 11.9 vs 127.8 +/- 12.5 kg), BMI (43.7 +/- 3.0 vs 45.2 +/- 3.5 kg/m2), operative time (167.1 +/- 72.7 vs 156.5 +/- 62.4 min), estimated blood loss (129.9 +/- 101.1 vs 166.8 +/- 127.3 cc), or length of stay (median, 3 vs 3 days; range, 2-18 vs 3-19). Body weight decreased over time in both groups, except in the sRYGB group between 3 and 6 months and 6 and 12 months after surgery and in the eRYGB group between 6 and 12 months. BMI also decreased over time, except in the eRYGB group between 6 and 12 months. Absolute weight loss leveled out between 6 and 12 months in both groups, with no increase after 6 months. Percent of excess weight loss did not increase in the eRYGB group after 6 months. An extended Roux limb did not significantly affect body weight, BMI, absolute weight loss, or precent of excess weight loss at any time point when the two groups were compared. A trend toward an increased proportion of patients with >50% excess weight loss ( p = 0.07) was observed in the extended Roux limb group. CONCLUSIONS: In this series, no difference in weight loss outcome variables were observed up to 1 year after laparoscopic RYGB. Thus, extending Roux limb length from < or =100 cm to 150 cm did not significantly improve weight loss outcome in patients with a BMI < 50 kg/m2.

Adult↗
PubMed2002

Alpha-helically constrained phage display library.

The library described here is a collection of phages with six degenerate codons in gene VIII, specifying amino acids 12, 13, 15-17 and 19 of the major coat protein. The randomized positions are surface exposed in the wild-type protein and thus might be expected to tolerate a great diversity of side chains without compromising phage viability. In agreement with this supposition, the new library showed great diversity of amino acids at the randomized positions and diversity did not diminish noticeably during repeated subculture. Despite their diversity, however, the randomized positions should be strongly constrained conformationally because they lie in an extended alpha-helical portion of the protein, stabilized by numerous inter- and intra-subunit contacts--a presupposition corroborated by circular dichroism spectroscopy of many library members. To reflect this conformational homogeneity and the fact that random amino acids subtend a major fraction of the surface 'landscape' of the particle, we call the new construct an alpha landscape library. It can be used as a source of alpha-helical ligands and substitute antibodies.

Capsid Proteins↗
PubMed2001

Role of prostaglandin E(2) and Ca(2+) in bradykinin induced contractions of guinea-pig gallbladder in vitro.

In this study, we investigated the contribution of prostaglandin E(2) to bradykinin induced contractions of guinea-pig gallbladder in vitro and characterized the sources of activator Ca(2+) for the bradykinin mediated contractions. Contractions induced by bradykinin in guinea-pig gallbladder smooth muscle strips were significantly attenuated by the cyclooxygenase inhibitor piroxicam (10 microM). In the presence of piroxicam, a threshold concentration of prostaglandin E(2) (1 nM) significantly enhanced the contractile response to subsequent challenge with bradykinin. Contractile responses to bradykinin were abolished in a Ca(2+)-free medium plus EDTA. The inhibitor of receptor mediated Ca(2+) entry, SK&F 96365 (1-[beta-[3-(4-methoxyphenyl)-propoxy]-4-methoxyphenethyl]-1H-imidazole hydrochloride, 10-50 microM) dose dependently abolished the response to bradykinin, while this response was only partially attenuated by nifedipine (10-50 microM; a voltage-operated Ca(2+) channel antagonist). Thapsigargin (an inhibitor of the sarcoplasmic reticulum calcium ATP-ase pump, 1 microM) produced sustained contractions of guinea-pig gallbladder strips that were dependent on extracellular Ca(2+). After incubation of strips in a Ca(2+)-free medium with thapsigargin, replacement of Ca(2+) caused a large sustained contraction. We conclude that the contractile response of guinea-pig gallbladder to bradykinin is modulated by prostaglandin E(2). Bradykinin induced contractions of guinea-pig gallbladder are highly dependent on extracellular Ca(2+) which enters through store-operated Ca(2+) channels and partially through voltage-operated Ca(2+) channels.

Animals↗
PubMed2001

Intracranial distribution of the sympathetic system in mice: DiI tracing and immunocytochemical labeling.

The intracranial distribution of the cephalic branches of the superior cervical ganglion (scg) was studied in mice using indocarbocyanine dye (DiI) anterograde tracing. Two main branches were traced from the scg. The first branch joined the nerve of the pterygoid canal (the vidian nerve), npc, from which several intracranial sympathetic branches passed to the branches of the trigeminal nerve (tgn), abducent nerve (abn), trochlear nerve (trn), and oculomotor nerve (ocn). Most of the second branch joined the abn, from which sympathetic fibers dispersed in the distal region of the trigeminal ganglion (tgg) to form a plexus close to the ganglion's branches. Branches from this plexus joined the branches of the tgn, trn, and ocn. Several minor branches arising from the second branch of the scg were also observed. One formed a sympathetic plexus around the internal carotid artery (ica); a second formed a sympathetic plexus in the proximal region of tgg, close to its root; and a third branch coursed laterally to reach the ear by passing along the greater petrosal nerve (gpn). All of the intracranial trajectories traced from scg were found to be catecholaminergic, and likely sympathetic, using tyrosine hydroxylase (TH) immunocytochemistry.

Abducens Nerve↗
PubMed2001

Down's syndrome, precocious puberty, and transverse vaginal septum: an unusual cause of abdominal pain.

Hematocolpos should be considered in adolescent girls who present with lower abdominal pain, a pelvic mass, and primary amenorrhea. The authors describe a rare case of a young child with Down's syndrome, precocious puberty, and hematocolpos caused by a transverse vaginal septum. The diagnosis was facilitated using a combination of computed tomography and ultrasound scanning. J Pediatr Surg 36:641-643.

Abdominal Pain↗
PubMed2001

Sources of calcium in neurokinin A-induced contractions of human colonic smooth muscle in vitro.

OBJECTIVES: Tachykinins have been implicated in the pathogenesis of colonic dysmotility. The sources of activator calcium for neurokinin A (NKA)-induced contraction of human colonic smooth muscle have not been assessed. We evaluated the contribution of extracellular and intracellular Ca2+ to NKA-induced contractions. METHODS: Circular smooth muscle strips of human colon were suspended under 1 g of tension in organ baths containing Krebs solution at 37 degrees C gased with 95% O2/5% CO2. Contractile activity was recorded isometrically. RESULTS: Cumulatively applied NKA (0.1 nmol/L-0.3 micromol/L), produced concentration-dependent contractions of human colonic smooth muscle strips that were not affected by tetrodotoxin (1 micromol/L). The contractile response to NKA was abolished in a Ca2+-free medium containing ethylenediaminetetraacetate (EDTA) (1 mmol/L). Pretreatment of muscle strips with nifedipine (1 micromol/L), an L-type voltage-operated Ca2+ channel antagonist, abolished the contractile responses to NKA. Pretreatment with SK&F 96365 (10 micromol/L and 30 micromol/L), a putative receptor-activated and voltage-operated Ca2+ channel antagonist, attenuated the contractile responses. Depletion of intracellular Ca2+ stores with thapsigargin (1 micromol/L), an inhibitor of the sarcoplasmic reticulum Ca2+ ATP-ase, had no effect on NKA-induced contractions. CONCLUSIONS: NKA-mediated contraction of human colonic smooth muscle is dependent on an influx of extracellular Ca2+ through L-type voltage-operated Ca2+ channels. Intracellular Ca2+ release seems to have little role to play in NKA-mediated contractions.

Calcium↗
PubMed2001

Multicenter evaluation of the BDProbeTec ET System for detection of Chlamydia trachomatis and Neisseria gonorrhoeae in urine specimens, female endocervical swabs, and male urethral swabs.

The performance of the Becton Dickinson BDProbe Tec ET System Chlamydia trachomatis and Neisseria gonorrhoeae Amplified DNA Assays (BD Biosciences, Sparks, Md.) was evaluated in a multicenter study. Specimens were collected from 2,109 men and women, with or without symptoms, attending sexually transmitted disease, family planning, and obstetrics and gynecology clinics. Both swab and urine samples were collected, and the results obtained from 4,131 specimens were compared to those from culture and the LCx nucleic acid amplification test (Abbott Industries, Abbott Park, Ill.). PCR and cytospin of the culture transport medium with chlamydia direct fluorescent antibody staining were used to adjudicate chlamydia culture-negative results. Sensitivity and specificity were calculated both with and without use of the amplification control (AC), with little apparent difference in the results. Without the AC result, sensitivity for C. trachomatis and N. gonorrhoeae were 92.8 and 96.6%, respectively, for cervical swabs and 80.5 and 84.9% for urine from women. C. trachomatis and N. gonorrhoeae sensitivities were 92.5 and 98.5%, respectively, for male urethral swabs and 93.1 and 97.9% for urine from men. This amplified DNA system for simultaneous detection of chlamydial and gonococcal infections demonstrated superior sensitivity compared to chlamydia culture and has performance characteristics comparable to those of other commercially available nucleic acid-based assays for these organisms.

Cervix Uteri↗
PubMed2001

Laparoscopic exclusion of a splenic artery aneurysm using a lateral approach permits preservation of the spleen.

Splenic artery aneurysms have commonly accepted therapeutic indications. Operative therapy for splenic artery aneurysms has traditionally consisted of aneurysm resection with a possible splenectomy. Recently, laparoscopic splenic artery aneurysm exclusion has been shown to provide adequate therapy without incurring the morbidity associated with aneurysmectomy and splenectomy. However, an anterior approach to exclusion may result in short gastric and left gastroepiploic artery disruption leading to splenic infarction. Preservation of the spleen can best be assured by a lateral approach, which preserves collateral splenic perfusion. A 51-year-old woman with a distal splenic artery aneurysm, who underwent an uncomplicated laparoscopic splenic artery aneurysm exclusion using a lateral approach, is described.

Aneurysm↗
PubMed2000

Screening females for chlamydia trachomatis (CT) In a large managed care organization (Mco). A new hedis measure

Background: Since CT testing for females is a new Health Plan Employer Data and Information Set (HEDIS) measure to assess MCO quality of care, we determined the proportion of females enrolled in a large closed panel vertically integrated MCO serving a demographically diverse population who were tested for CT at least once during 1998 and resulting CT prevalences.Methods: A data base with MCO members >/= 12 yrs old tested with CT DNA probes (GenProbe) from 1/1/98-12/30/98 was examined. Only females 12-24 yrs old and enrolled at least 11 continuous months in 1998 were included in the analysis.Results: In 1998, 5425 (13.1%) of 41,566 females 12-24 yrs were CT tested and 849 (2.0%) tested positive at least once. Proportion of females tested and proportion of females testing positive at least once varied by age and clinic location. Among 11, 562 12-14 yr females, 277 (2.4%) were CT tested and 48 (0.4%) tested positive; among 18,155 15-19 yr females, 2,424 (13.4%) were tested and 572 (3.2%) tested positive; and among 11,849 20-24 yr females, 2, 724 (23.0%) were tested and 229 (1.9%) tested positive. The proportion 12-24 yr females tested was 579/3,945 (14.7%) with 92/3, 945 (2.3%) testing positive in the Baltimore area; in Washington, DC/Maryland area 2,999/21,085 (14.2%) were tested with 601/21,085 (2. 9%) testing positive; in Northern Virginia 1,847/16,536 (11.2%) were tested with 156/16,536 (0.9%) testing positive.Proportion of females with at least one positive test among those females who were tested for CT also varied by age and clinic location. Among 277 of 12-14 yr females tested 48 (17.3%) tested positive at least once; among 2,424 of 15-19 yr females tested, 572 (23.6%) tested positive at least once; and among 2,724 of 20-24 yr females tested, 229 (8.4%) tested positive at least once. The proportion of females tested with at least one positive test among 12-24 yr females was 92/579 (15.9%) in the Baltimore area, 601/2,999 (20.0%) in Washington DC/Maryland area, and 156/1,847 (8.4%) in Northern Virginia.Conclusion: CT testing of adolescent females 12-19 yrs revealed a high proportion of positive tests. The lower proportion of positive tests in young adults 20-24 yrs may be due to differences in prevalence and increased number of tests performed. CT testing practices and rates varied by location. Therefore, in a large MCO, a uniform system wide approach in identifying and screening sexually active adolescent females may identify a large reservoir or asymptomatic infection.

Journal Article↗
PubMed2000

Determining chest pain patients' suitability for transfer to a general ward following admission to a cardiac care unit.

The objective of this study was to assess the performance of a consensus-derived decision algorithm in determining chest pain patients' suitability for early transfer to a lower dependency ward by predicting complications. The sample comprised 516 patients with chest pain presumed to be cardiac in origin, admitted to a cardiac care unit (CCU) in northern England from the community or from the accident and emergency department. A decision algorithm was designed following a review of the literature and amended to take into account a clinical consensus of consultant physicians. Patients were assessed on admission by CCU nurses using the algorithm, and 'triage' decisions recorded (keep on CCU or suitable for early transfer to a general ward). Admission ECGs (electrocardiographs) and baseline clinical data were recorded independently by a researcher 'blinded' to actual clinical course, and applied to the algorithm using statistical software. On discharge or death, patients' case notes were retrieved and the hospital course examined for death or severe complications. Performance of the algorithm and CCU nurses were compared for sensitivity, specificity, positive predictive value and negative predictive value. The main outcome measures were death or severe complications occurring during hospitalization, and during the first 2 days following CCU admission. While sensitivity of both the algorithm (0.98) and CCU nurses (0.95) was high, specificity was low in both groups (0.11 and 0.21, respectively), making it unlikely that the algorithm would prove useful in clinical practice. Further studies are required to develop the optimal triage tool for the assessment of patients with acute chest pain.

Aged↗
PubMed2000

Improving door to needle times with nurse initiated thrombolysis.

OBJECTIVE: To evaluate the effect of nurse initiated thrombolysis on door to needle time (the interval between arriving at the hospital and starting thrombolytic treatment) in patients with acute myocardial infarction. DESIGN: Comparison of door to needle times before and after the employment of nurses trained and approved to initiate thrombolysis without prescription by a doctor but with a protocol for rapid triage of patients with chest pain. SETTING: A district general hospital. SUBJECTS: All patients admitted with suspected myocardial infarction between April 1995 and March 1999. MAIN OUTCOME MEASURES: Speed (door to needle time) and appropriateness of administration of thrombolytic drugs to patients with acute myocardial infarction who gave a characteristic history and had appropriate criteria on the admission ECG. RESULTS: During seven periods (each of four months) before the introduction of nurse initiated thrombolysis and a new chest pain triage protocol, the median door to needle time varied from 50-58 minutes. In four periods (each of 4-6 months) following the introduction of the changes, the median door to needle time was 25-30 minutes. The improvement was significant (p < 0.001). Nurses trained to initiate thrombolysis currently provide cover for 66% of the time. Median door to needle time for nurses was 15 minutes. Median door to needle time for junior doctors improved to 35 minutes. The median door to needle times when nurses initiated thrombolysis was significantly shorter than when doctors did so (p < 0.001). There have been no inappropriate management decisions by nurses approved to initiate thrombolysis. CONCLUSIONS: The use of nurse initiated thrombolysis has resulted in a clinically important reduction in the time taken for thrombolysis to be started in patients with acute myocardial infarction.

Coronary Care Units↗
PubMed1999

Short-term effects of large-dose vitamin A supplementation on viral load and immune response in HIV-infected women.

Vitamin A supplementation has been suggested for treatment and prevention of HIV infection. However, some in vitro data indicate that vitamin A may activate HIV. Randomly, 40 HIV-seropositive women of reproductive age were allocated to receive a single oral dose of 9900 micromol (300,000 IU) vitamin A or placebo. Plasma HIV-1 RNA concentration, total lymphocytes, selected lymphocyte subsets and activation markers, and in vitro lymphocyte proliferation to phytohemagglutinin (PHA) and Candida were measured before dosing and at various time points over an 8-week follow-up period. No differences were found between treatment groups in the frequency of signs or symptoms of acute vitamin A toxicity, nor were differences evident in any lymphocyte subset or activation marker at any time during follow-up. Mean and median viral load concentration at each time point and change in viral load from baseline to each follow-up point did not differ between treatment groups. No difference was measured between treatment groups in the proportion of women who responded to PHA or Candida. This study provides no evidence that high dose vitamin A supplementation of HIV-infected women is associated with significant clinical or immunologic adverse effects.

Adult↗
PubMed1999

History and development of coronary care.

The first coronary care units (CCUs) were opened in the 1960s in an attempt to reduce mortality from acute myocardial infarction (AMI). Nurses were closely involved in the development and success of these early units. This paper will provide an overview of the history and development of the CCU, including nurses' crucial involvement in pioneering the first CCUs in the 1960s through to the emerging role of nurses in the care of cardiac patients in the late 1990's.

Coronary Care Units↗
PubMed1999

Mutations in a gene encoding a new oxygen-regulated photoreceptor protein cause dominant retinitis pigmentosa.

The autosomal dominant retinitis pigmentosa (RP) locus, designated RP1, has been mapped through linkage studies to a 4-cM interval at 8q11-13. Here we describe a new photoreceptor-specific gene that maps in this interval and whose expression is modulated by retinal oxygen levels in vivo. This gene consists of at least 4 exons that encode a predicted protein of 2,156 amino acids. A nonsense mutation at codon 677 of this gene is present in approximately 3% of cases of dominant RP in North America. We also detected two deletion mutations that cause frameshifts and introduce premature termination codons in three other families with dominant RP. Our data suggest that mutations in this gene cause dominant RP, and that the encoded protein has an important but unknown role in photoreceptor biology.

Amino Acid Sequence↗
PubMed1998

Patterns of HIV-1 evolution in individuals with differing rates of CD4 T cell decline.

Evolution of HIV-1 env sequences was studied in 15 seroconverting injection drug users selected for differences in the extent of CD4 T cell decline. The rates of increase of either sequence diversity at a given visit or divergence from the first seropositive visit were both higher in progressors than in nonprogressors. Viral evolution in individuals with rapid or moderate disease progression showed selection favoring nonsynonymous mutations, while nonprogressors with low viral loads selected against the nonsynonymous mutations that might have resulted in viruses with higher levels of replication. For 10 of the 15 subjects no single variant predominated over time. Evolution away from a dominant variant was followed frequently at a later time point by return to dominance of strains closely related to that variant. The observed evolutionary pattern is consistent with either selection against only the predominant virus or independent evolution occurring in different environments within the host. Differences in the level to which CD4 T cells fall in a given time period reflect not only quantitative differences in accumulation of mutations, but differences in the types of mutations that provide the best adaptation to the host environment.

Base Sequence↗