PubMed Health⌕ Search

Biomedical subjects

J Collins

Publications and source records attributed to J Collins.

At least 37 records · Page 2Linked to original sources
PubMed2003

Modest evidence for linkage and possible confirmation of association between NOTCH4 and schizophrenia in a large Veterans Affairs Cooperative Study sample.

Wei and Hemmings [2000: Nat Genet 25:376-377], using 80 British parent-offspring trios, identified a number of NOTCH4 variants and haplotypes that showed statistically significant evidence of association to schizophrenia. Specifically, the 10 repeat allele of a (CTG)(n) marker and the 8 repeat allele of a (TAA)(n) marker demonstrated excess transmission to affected individuals; SNP21 and haplotypes SNP2-(CTG)(n) and SNP12-SNP2-(CTG)(n) also showed significant associations. In an attempt to replicate these findings, we tested for linkage and association between the same five markers used by Wei and Hemmings in 166 families collected from a multi-center study conducted by the Department of Veterans Affairs (DVA) Cooperative Study Program (CSP). The families include 392 affected subjects (schizophrenia or schizoaffective disorder, depressed) and 216 affected sibling pairs. The families represent a mix of European Americans (n = 62, 37%), African Americans (n = 60, 36%), and racially mixed or other races (n = 44, 27%). We identified moderate evidence for linkage in the pooled race sample (LOD = 1.25) and found excess transmission of the 8 (P = 0.06) and 13 (P = 0.04) repeat alleles of the (TAA)(n) marker to African American schizophrenic subjects. The 8 and 13 repeat alleles were previously identified to be positively associated with schizophrenia by Wei and Hemmings [2000: Nat Genet 25:376-377] and Sklar et al. [2001: Nat Genet 28:126-128], respectively.

Alleles↗
PubMed2003

Risk factors for locoregional recurrence among breast cancer patients: results from International Breast Cancer Study Group Trials I through VII.

PURPOSE: To explore prognostic factors for locoregional failures (LRF) among women treated for invasive breast cancer within clinical trials of adjuvant therapies. PATIENTS AND METHODS: The study population consisted of 5,352 women who were treated with a modified radical mastectomy and enrolled in one of seven International Breast Cancer Study Group randomized trials. A total of 1,275 women with node-negative disease received either no adjuvant therapy or a single cycle of perioperative chemotherapy, and 4,077 women with node-positive disease received adjuvant chemotherapy of at least 3 months' duration and/or tamoxifen. Median follow-up is 12 to 15.5 years. RESULTS: In women with node-negative disease, factors associated with increased risk of LRF were vascular invasion (VI) and tumor size greater than 2 cm for premenopausal and VI for postmenopausal patients. Of the 1,275 patients, 345 (27%) met criteria for the highest risk groups, and the 10-year cumulative incidences of LRF with or without distant metastases were 16% for premenopausal and 19% for postmenopausal women. For the node-positive cohort, number of nodes and tumor grade were factors for both menopausal groups, with additional prediction provided by VI for premenopausal and tumor size for postmenopausal patients. Of the 4,077 patients, 815 (20%) met criteria for the highest risk groups, and 10-year cumulative incidences were 35% for premenopausal and 34% for postmenopausal women. CONCLUSION: LRFs are a significant problem after mastectomy alone even for some patients with node-negative breast cancer, as well as after mastectomy and adjuvant treatment for some subgroups of patients with node-positive disease. In addition to number of positive lymph nodes, predictors of LRF include tumor-related factors, such as vascular invasion, higher grade, and larger size.

Breast Neoplasms↗
PubMed2003

The effects of pregnancy and estrogen on the expression of calcitonin gene-related peptide (CGRP) in the uterine cervix, dorsal root ganglia and spinal cord.

Before parturition the uterine cervix undergoes a ripening process ("softens" and dilates) to allow passage of the fetus at term. The exact mechanism(s) responsible for cervical ripening are unknown, though a role for peptidergic sensory neurons is emerging. Previous work demonstrated that administration of substance P (SP) to ovariectomized rats caused events associated with cervical ripening, that production of SP in cervix-related dorsal root ganglion (DRG) is estrogen responsive, and that release of SP from neurons terminating in the cervix and spinal cord peaks prior to parturition. The present study was designed to test the hypothesis that calcitonin gene-related peptide (CGRP), a neuropeptide co-stored with SP in many sensory neurons, undergoes changes with pregnancy and hormonal environment. Immunohistochemistry, in situ hybridization, reverse transcriptase-polymerase chain reaction (RT-PCR) and radioimmunoassay (RIA) were used to investigate CGRP in L6-S1 DRG, spinal cord and cervix during pregnancy and the role of estrogen in CGRP synthesis. CGRP-immunoreactive primary sensory neurons expressed estrogen receptors (ER-alpha and ER-beta). In the cervix, CGRP concentrations decreased, but in the L6-S1 DRG and the spinal cord segments, CGRP levels increased, with peak effects observed at day 20 of gestation. CGRP mRNA synthesis increased in DRG over pregnancy. Sensory neurons of ovariectomized rats treated with estrogen showed increased CGRP mRNA synthesis in a dose-related manner, an effect blocked by the ER antagonist ICI 182 780. From these results, we postulate that synthesis of CGRP in L6-S1 DRG and utilization in the cervix increase over pregnancy and this synthesis is the under influence of the estrogen-ER system. Collectively, these data are consistent with the hypothesis that CGRP plays a role in cervical ripening and, consequently in the birth process.

Animals↗
PubMed2002

Long-term survival of aortic atresia following biventricular corrective surgery.

A female born with aortic atresia, large ventricular septal defect, normal mitral valve, and left ventricle is well at 21 years of age following biventricular repair. She had palliative surgery at 15 days and closure of ventricular septal defect with placement of a valved conduit from the left ventricular apex to descending aorta at 15 months. Conduit was replaced at 34 months and at 10 and 21.5 years of age.

Adult↗
PubMed2002

Duration of adjuvant chemotherapy for breast cancer: a joint analysis of two randomised trials investigating three versus six courses of CMF.

Cyclophosphamide, methotrexate and fluorouracil adjuvant combination chemotherapy for breast cancer is currently used for the duration of six monthly courses. We performed a joint analysis of two studies on the duration of adjuvant cyclophosphamide, methotrexate and fluorouracil in patients with node-positive breast cancer to investigate whether three courses of cyclophosphamide, methotrexate and fluorouracil might suffice. The International Breast Cancer Study Group Trial VI randomly assigned 735 pre- and perimenopausal patients to receive 'classical' cyclophosphamide, methotrexate and fluorouracil for three consecutive cycles, or the same chemotherapy for six consecutive cycles. The German Breast Cancer Study Group randomised 289 patients to receive either three or six cycles of i.v. cyclophosphamide, methotrexate and fluorouracil day 1, 8. Treatment effects were estimated using Cox regression analysis stratified by clinical trial without further adjustment for covariates. The 5-year disease-free survival per cents (+/-s.e.) were 54+/-2% for three cycles and 55+/-2% for six cycles (n=1024; risk ratio (risk ratio: CMFx3/CMFx6), 1.00; 95% confidence interval, 0.85 to 1.18; P=0.99). Use of three rather than six cycles was demonstrated to be adequate in both studies for patients at least 40-years-old with oestrogen-receptor-positive tumours (n=594; risk ratio, 0.86; 95% confidence interval, 0.68 to 1.08; P=0.19). In fact, results slightly favoured three cycles over six for this subgroup, and the 95% confidence interval excluded an adverse effect of more than 2% with respect to absolute 5-year survival. In contrast, three cycles appeared to be possibly inferior to six cycles for women less than 40-years-old (n=190; risk ratio, 1.25; 95% confidence interval, 0.87 to 1.80; P=0.22) and for women with oestrogen-receptor-negative tumours (n=302; risk ratio, 1.15; 95% confidence interval, 0.85 to 1.57; P=0.37). Thus, three initial cycles of adjuvant cyclophosphamide, methotrexate and fluorouracil chemotherapy were as effective as six cycles for older patients (40-years-old) with oestrogen-receptor-positive tumours, while six cycles of adjuvant cyclophosphamide, methotrexate and fluorouracil might still be required for other cohorts. Because endocrine therapy with tamoxifen and GnRH analogues is now available for younger women with oestrogen-receptor-positive tumours, the need for six cycles of cyclophosphamide, methotrexate and fluorouracil is unclear and requires further investigation.

Adult↗
PubMed2001

Examination of genetic linkage of chromosome 15 to schizophrenia in a large Veterans Affairs Cooperative Study sample.

Previous studies have reported genetic linkage evidence for a schizophrenia gene on chromosome 15q. Here, chromosome 15 was examined by genetic linkage analysis using 166 schizophrenia families, each with two or more affected subjects. The families, assembled from multiple centers by the Department of Veterans Affairs Cooperative Study Program, consisted of 392 sampled affected subjects and 216 affected sibling pairs. By DSM-III-R criteria, 360 subjects (91.8%) had a diagnosis of schizophrenia and 32 (8.2%) were classified as schizo-affective disorder, depressed. Participating families had diverse ethnic backgrounds. The largest single group were northern European American families (n = 62, 37%), but a substantial proportion was African American kindreds (n = 60, 36%). The chromosome 15 markers tested were spaced at intervals of approximately 10 cM over the entire chromosome and 2-5 cM for the region surrounding the alpha-7 nicotinic cholinergic receptor subunit gene (CHRNA7). These markers were genotyped and the data analyzed using semiparametric affecteds-only linkage analysis. In the European American families, there was a maximum Z-score of 1.65 between markers D15S165 and D15S1010. These markers are within 1 cM from CHRNA-7, the site previously implicated in schizophrenia. However, there was no evidence for linkage to this region in the African America kindreds.

Adult↗
PubMed2001

Influence of endocrine-related factors on response to perioperative chemotherapy for patients with node-negative breast cancer.

PURPOSE: We investigated tumor- and patient-related features that might influence the response to perioperative chemotherapy (PeCT) compared with no adjuvant therapy for patients with node-negative breast cancer. PATIENTS AND METHODS: A total of 1,275 patients were randomized to either no adjuvant treatment (427 patients) or PeCT (848 patients). The following variables thought to have prognostic significance were evaluated: grade, tumor size, estrogen (ER) and progesterone receptor (PgR) content (absent; low, 1 to 9 fmol/mg cytosol protein; or positive, > or = 10 fmol/mg cytosol protein), c-erbB-2 overexpression, menopausal status, and age. Cox proportional hazards regression models were used to assess the relative influence of these factors to predict the effect of PeCT on disease-free survival (DFS). Median follow-up was 13.5 years. RESULTS: The 10-year DFS percentage for 692 premenopausal patients did not significantly differ between the PeCT and no-adjuvant-treatment groups: 61% and 59%, respectively (relative risk [RR], 0.95; 95% confidence interval [CI], 0.75 to 1.20; P = .70). No predictive factors were identified. For 583 postmenopausal patients, 10-year DFS percentages for the groups were 63% and 58%, respectively (RR, 0.75; 95% CI, 0.58 to 0.93; P = .03). The absence of expression of ER, PgR, or both ER and PgR was the most important factor predicting improved outcome with PeCT among postmenopausal patients. The 10-year DFS percentages were 85% and 53% for the steroid hormone receptor-absent cohort of treated and untreated patients, respectively (RR, 0.18; 95% CI, 0.06 to 0.49; P = .0009). CONCLUSION: The role of PeCT should be explored for patients whose primary tumors do not express steroid hormone receptors, because it is likely that early initiation of treatment is exclusively relevant for such patients.

Adult↗
PubMed2001

Mice lacking the chemokine receptor CCR1 show increased susceptibility to Toxoplasma gondii infection.

Chemokines are critical for the recruitment of effector immune cells to sites of infection. Mice lacking the chemokine receptor CCR1 have defects in neutrophil trafficking and proliferation. In the present study, we tested the susceptibility of CCR1 knockout mice to infection with the obligate intracellular protozoan parasite Toxoplasma gondii. In comparison with parental wild-type mice, CCR1(-/-) mice exhibited dramatically increased mortality to T. gondii in association with an increased tissue parasite load. No differences were observed in Ag-specific T cell proliferation or in cytokine responses between mutant and wild-type mice. However, the influx of PMNs to the peripheral blood and to the liver were reduced in CCR1(-/-) mice during early infection. Our results suggest that CCR1-dependent migration of neutrophils to the blood and tissues may have a significant impact in controlling parasite replication.

Animals↗
PubMed2001

Acceleration of lung disease in children with cystic fibrosis after Pseudomonas aeruginosa acquisition.

As part of the ongoing Wisconsin Cystic Fibrosis (CF) Neonatal Screening Project, we had the unique opportunity to study the longitudinal relationship between Pseudomonas aeruginosa (Pa) acquisition and infection and developing lung disease in children with CF. The primary objective was to determine whether acquisition of Pa was associated with a measurable change in the progression of lung disease. Two outcome measures were used to study 56 patients who were diagnosed through newborn screening: 1) Wisconsin additive chest radiograph score (WCXR), based on the average of scores from a pulmonologist and a radiologist, and 2) the highest forced expired volume in 1 sec (FEV(1))/forced vital capacity (FVC) ratio. We used two measures of Pa acquisition: 1) time of first positive protocol-determined oropharyngeal (with cough) culture, and 2) the magnitude of antibody titer detected by ELISA assays, using as antigen a crude cell lysate, purified exotoxin A, or an elastase toxoid prepared from three Pa strains. Other predictor variables included age, pancreatic status, height-for age, and weight-for-age-percentiles. The best regression model for predicting changes in the WCXR included time to first positive culture and antibody titer for Pa elastase. Prior to Pa acquisition, WCXR worsened by 0.45 points/year (P > 0.25); after Pa acquisition, the rate of worsening increased significantly (P < 0.001) to 1.40 points/year. Each antibody titer level (log base 2) increased the score by 0.48 points (P < 0.001). The best regression model for predicting change in the FEV(1)/FVC included only time to first positive culture. Prior to Pa acquisition, the FEV(1)/FVC ratio declined by 1.29%/year; after Pa infection, the rate of decrease significantly accelerated to 1.81%/year (P = 0.001). Our data show that Pa acquisition is associated with declining pulmonary status in children with CF, and that this effect is probably gradual rather than precipitous. Because these patients were diagnosed and treated aggressively, our estimates of the effects of Pa acquisition may be conservative. We also conclude that the WCXR appears to be more sensitive than FEV(1)/FVC in detecting early changes in lung disease associated with CF.

Age Distribution↗
PubMed2001

Bioavailability of penclomedine and systemic exposure to 4-O-demethylpenclomedine in patients receiving oral and intravenous penclomedine.

PURPOSE: Oral administration of penclomedine was investigated based on preclinical studies indicating that an oral schedule of penclomedine treatment may prevent the neurotoxicity observed in phase I studies of an intravenous (i.v.) formulation, possibly by reducing maximum plasma concentrations (Cmax) of the neurotoxic parent species. METHODS: Penclomedine was administered i.v. (200 mg/m2) and orally (250 mg/m2) in alternate sequences to patients with solid tumor malignancies. Plasma concentrations of parent drug and the principal metabolite, 4-O-demethylpenclomedine, were determined by a reversed-phase HPLC assay. RESULTS: Penclomedine was detectable in the plasma of all patients within 1 h of oral penclomedine treatment and Cmax was reached within 1 to 4 h. Consistent with the hypothesis that an oral schedule of administration may circumvent neurotoxicity, a paired data analysis demonstrated a significant reduction in Cmax values following oral administration (P=0.017). However the magnitude of this reduction was highly variable. Similarly an extensive range in the relative exposure to both parent drug and metabolite were observed. The bioavailability of penclomedine ranged from 28% to 98% (median 73%). CONCLUSIONS: Oral penclomedine does produce systemic exposure, but substantial interpatient variability in absorption and systemic exposure is present which may limit the clinical role of the oral route of administration.

Administration, Oral↗
PubMed2001

CT signs and patterns of lung disease.

The ground-glass pattern is a common but nonspecific finding on CT. In certain clinical circumstances, it can suggest a specific diagnosis, indicate a potentially treatable disease, and guide a clinician to an appropriate area for biopsy. A pattern of centrilobular ground-glass nodules is fairly specific for the diagnosis of hypersensitivity pneumonitis with the appropriate clinical history. The tree-in-bud pattern indicates disease affecting the small airways. The differential diagnosis is lengthy; however, the most common process leading to this CT appearance is infection. Although commonly associated with M. tuberculosis, many infectious organisms can produce this pattern. When honeycombing is seen on HRCT, a confident diagnosis of lung fibrosis can be made. The most common causes of interlobular septal thickening on HRCT are pulmonary edema, pulmonary hemorrhage, and lymphangitic spread of cancer, and smooth thickening is characteristic of all three. Diffuse lung cysts in patients who are not immunocompromised generally signify Langerhans' cell histiocytosis, lymphangioleiomyomatosis, or centrilobular emphysema. Centrilobular emphysema can be diagnosed when the centrilobular artery is seen as a small nodular opacity in the center of the cyst. Langerhans' cell histiocytosis is often associated with parenchymal nodules, helping to distinguish it from lymphangioleiomyomatosis. When a nodular pattern is seen on HRCT, the differential diagnosis is very long, but can be narrowed by noting whether the nodules are random, centrilobular, or perilymphatic in distribution. A mosaic pattern of lung attenuation can represent an infiltrative, small airway, or vascular process. The distinction can often be made by noting the size of the pulmonary vessels in the abnormal areas of lung, and whether air trapping is present on expiratory scanning. Computed tomographic signs can be useful indicators of a specific disease process. For instance, the air bronchogram sign indicates that an opacity is intrapulmonary in location, and signals the possibility of two types of neoplasm: lymphoma and bronchioloalveolar cell carcinoma. An air crescent sign indicates recovery of the immune system in an immunocompromised patient with invasive pulmonary aspergillosis. The fallen lung sign is diagnostic of a bronchial transection in the correct clinical setting. The gloved finger sign is very suggestive of allergic bronchopulmonary aspergillosis. The halo sign is highly suggestive of early angioinvasive pulmonary aspergillosis in patients with acute leukemia. When a split pleura sign is seen, the diagnosis is often empyema, although other causes of pleuritis can lead to a similar CT appearance.

Diagnosis, Differential↗
PubMed2001

Journal publications in radiologic education: a review of the literature, 1987-1997.

RATIONALE AND OBJECTIVES: This study was designed to analyze articles on radiologic education quantitatively and qualitatively, comparing those published in 1987-1997 with those published in 1966-1986. MATERIALS AND METHODS: An initial literature search used four major databases to identify and retrieve articles related to radiologic education. Additional articles were identified through manual cross-checking of references from the original articles. All articles were reviewed by two radiologists as to type of article (editorial, expository, survey, correlational, or experimental, including preexperimental, quasi-experimental, or true experimental), statistics used (inferential or descriptive), educational emphasis (medical student, resident, postgraduate, or other), and topic of article (philosophical or political, technology, program evaluation, program description, examinations, or career decisions). Interrater agreement was estimated by means of the kappa statistic. A chi2 test for independence was used to assess whether the relative distribution of articles was similar for the two periods. RESULTS: More articles per year were published in 1987-1997 (n = 12.6, P < .01) compared with 1966-1986 (n = 9.2). Articles pertinent to radiologic resident education predominated (50.7% vs 29.9% in the prior study, P < .01). In both periods, most articles were expository (37.7% vs 49.5%), and the most common topic was program description (34% vs 35%). Editorials decreased from 35.5% to 18.1%. Experimental studies accounted for 12.3%, increased from 8.7%. The fastest-growing topic of study was technology (30.4% vs 17.5%, P < .01). CONCLUSION: The increased number of articles addressing radiologic education is encouraging. Although the percentage of experimental studies increased slightly in this period, there is still little empirical research in radiologic education.

Bibliometrics↗
PubMed2001

2001 Joseph E. and Nancy O. Whitley Award. Teaching noninterpretive skills to radiology residents: a collaborative effort between the American College of Radiology and the Association of Program Directors in Radiology.

RATIONALE AND OBJECTIVES: The authors' purpose was to develop, implement, and evaluate a series of videotapes for teaching noninterpretive skills to radiology residents. MATERIALS AND METHODS: An Association of Program Directors in Radiology/American College of Radiology working group developed a series of seven videotapes to teach residents job search and contracting skills; business aspects of radiology; American College of Radiology standards, accreditation programs, and appropriateness criteria; critical thinking skills; ethics; service orientation and interpersonal skills; and medical organizational politics. Residents viewed the videotapes, evaluated the learning experience, and completed both pre- and posttests. RESULTS: From 85 to 264 residents completed each of six pre- and posttests. Mean total pretest scores ranged from 55.0% to 76.9% and improved significantly (P < .05) to 73.8% to 94.9% on posttests. Each videotape was evaluated by 90-336 residents using a Likert-type scale, with a rating of 5 representing the most positive response. The proportion of residents who gave each tape an overall rating of either 4 or 5 varied from 75.9% to 95.9%. CONCLUSION: Significant resident learning occurred as a result of viewing the videotapes. Program director support of the learning experience was strong, and use of the videotapes as a teaching modality received strong support by residents. Local moderators and question-and-answer sessions would optimize the learning experience.

Awards and Prizes↗