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Biomedical subjects

T O'Connor

Publications and source records attributed to T O'Connor.

At least 55 records · Page 3Linked to original sources
PubMed1999

Validation of the Brief Pediatric Asthma Screen.

STUDY OBJECTIVES: The purpose of this study was to confirm the validity of a brief screen for pediatric asthma in schools. BACKGROUND: Asthma is the most common chronic disease of childhood, yet the frequency with which this condition is recognized among school-aged children varies widely. Several methods are used to increase the accuracy of detection of asthma, but many are cumbersome and difficult to apply on a large scale. DESIGN: We elected to validate a five-question instrument, the Brief Pediatric Asthma Screen (BPAS), to screen for the presence of asthma among children attending school in Region 5 of the Chicago school district, where the schools report a 2.7% frequency of asthma. The questionnaire was distributed to the parents of grade-school children at the time of report-card pick-up. SETTING: A clinical assessment was performed on a selected group of children whose parents completed the questionnaire in a school and in a hospital outpatient clinic. PARTICIPANTS: Of 4,147 questionnaires that we distributed, 1,796 (43%) were returned. We excluded 341 children (19% of the total sample) whose parents reported that they had been diagnosed with asthma. The remaining pool indicated that the children of 183 responders (10%) had symptoms suggestive of asthma, while 1,272 parents (71%) indicated that their children did not have symptoms of asthma. MEASUREMENTS AND RESULTS: We selected 90 of the respondents who did not indicate that their children had a diagnosis of asthma. Of this group, 81 completed the validation, in which their responses suggested symptoms of asthma (n = 34) or no asthma symptoms (n = 47). The children of these respondents were given a blinded clinical evaluation consisting of history, physical examination, and spirometry. The survey demonstrated a sensitivity of 75% and a specificity of 81.2% for the presence of asthma among those who were unaware of the diagnosis. CONCLUSIONS: The BPAS is brief, can be filled out by parents, and appears accurate in detecting asthma.

Asthma↗
PubMed1999

Genetics and child psychiatry: I Advances in quantitative and molecular genetics.

Advances in quantitative psychiatric genetics as a whole are reviewed with respect to conceptual and methodological issues in relation to statistical model fitting, new genetic designs, twin and adoptee studies, definition of the phenotype, pervasiveness of genetic influences, pervasiveness of environmental influences, shared and nonshared environmental effects, and nature-nurture interplay. Advances in molecular genetics are discussed in relation to the shifts in research strategies to investigate multifactorial disorders (affected relative linkage designs, association strategies, and quantitative trait loci studies); new techniques and identified genetic mechanisms (expansion of trinucleotide repeats, genomic imprinting, mitochondrial DNA, fluorescent in-situ hybridisation, behavioural phenotypes, and animal models); and the successful localisation of genes.

Adolescent↗
PubMed1999

Genetics and child psychiatry: II Empirical research findings.

Key substantive findings from quantitative and molecular genetic research are reviewed in relation to affective disorder, schizophrenia, autism, hyperkinetic/attention deficit disorder, oppositional and conduct disorders, drug/alcohol problems, and Tourette's syndrome/chronic tics.

Adolescent↗
PubMed1998

Restriction endonuclease-mediated selective polymerase chain reaction: a novel assay for the detection of K-ras mutations in clinical samples.

The enriched polymerase chain reaction (PCR) assay has been used extensively in the detection of ras gene mutations in many types of human malignancies. Although it is very sensitive, it has a number of features that limit its use in the routine diagnostic laboratory. The aim of this study was to develop a novel enriched PCR strategy, in which the concurrent activity of the restriction enzyme BstNI and Taq polymerase allowed the amplification of mutant K-ras while inhibiting the formation of wild-type product. This restriction endonuclease-mediated selective PCR assay uses three sets of primers, together with BstNI, in the reaction mix, and the amplification products are analyzed by gel electrophoresis. The reliability of the restriction endonuclease-mediated selective PCR assay to detect activated K-ras was determined in a variety of clinical samples, including 139 fresh colorectal carcinomas and 113 paraffin-embedded blocks from 80 separate tumors of the colon and rectum, pancreas, breast, or kidney. Codon 12 mutations of the K-ras oncogene were identified in DNA from both fresh and paraffin-embedded tumors in a rapid, sensitive, and reproducible manner. Mutations were detected in 33 (24%) of the fresh colorectal cancers and 16 (20%) of the paraffin-embedded tumors. These results were 97% concordant in cases in which paraffin blocks and fresh specimens from the same tumor were available for analysis. We conclude that restriction endonuclease-mediated selective PCR is a sensitive, rapid, and robust assay for the detection of point mutations in a variety of clinical samples. Importantly, there is no need for manipulation of the sample once the PCR has been set up, and therefore, the chance of contamination is significantly reduced. In contrast to previous assays, restriction endonuclease-mediated selective PCR is not labor intensive, and its format is suitable for use in routine diagnostic laboratory.

Adenocarcinoma↗
PubMed1998

Urokinase protocol for free-flap salvage following prolonged venous thrombosis.

The incidence of free-flap failure is reported at 4 to 5 percent. Often, these failures are attributed to postoperative venous thrombosis with salvage rates reported at 42 percent. The use of thrombolytics has been effective in laboratory protocols; however, there have been only case reports to substantiate their use in humans. In this study, we establish a protocol for the administration of urokinase for postoperative venous thrombosis. Upon clinical evidence of venous thrombosis, all patients were urgently returned to the operating room, where the venous anastomosis was resected and a new venous anastomosis was performed. A solution of 250,000 units of urokinase was then infused over 30 minutes through a 25-gauge butterfly inserted into the recipient artery just proximal to the arterial anastomosis. Patients were continued on a daily aspirin (325 mg). More than 600 free flaps have been performed by our group since 1990. In that group of patients, five were diagnosed with postoperative venous thrombosis. Flaps consisted of four radial forearm flaps and one free transverse rectus abdominis muscle flap. All patients were diagnosed late based upon significant changes within the flap. Thromboses were clinically apparent on postoperative days 1 through 6, with an average of 3.6 days. All five patients received urokinase as described. The average age of the patients treated was 43. There were no postoperative hematomas, blood transfusions, or bleeding complications. There were no allergic or anaphylactic reactions to the urokinase. All flaps survived (100 percent) with a mean follow-up of 27 months. The use of urokinase as described in our protocol has been an effective thrombolytic, capable of reversing clinically advanced venous thrombosis when combined with repeated venous anastomosis. We believe this protocol provides a viable option for the treatment of postoperative venous thrombosis.

Adult↗