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Biomedical subjects

J Collins

Publications and source records attributed to J Collins.

At least 19 recordsLinked to original sources
PubMed2006

Among patients treated for IVF with gonadotrophins and GnRH analogues, is the probability of live birth dependent on the type of analogue used? A systematic review and meta-analysis.

This systematic review and meta-analysis aimed to answer the following clinical question: among patients treated for IVF with gonadotrophins and GnRH analogues, is the probability of live birth per randomized patient dependent on the type of analogue used? Eligible studies were randomized controlled trials (RCTs), published as a full manuscript in a peer-reviewed journal, that contained sufficient information to allow ascertainment of whether randomization was true and whether equality was present between the groups compared. A literature search identified 22 RCTs comparing GnRH antagonists and GnRH agonists that involved 3176 subjects. Where live birth was not reported in a study that fulfilled the inclusion criteria, an effort was made to contact the corresponding authors to retrieve the missing information. If this was not possible, the reported outcome measure, clinical pregnancy or ongoing pregnancy was converted to live birth in 12 studies using published data (Arce et al., 2005). No significant difference was present in the probability of live birth between the two GnRH analogues [odds ratio (OR), 0.86; 95% confidence intervals (CI), 0.72 to 1.02]. This result remains stable in subgroup analysis that ordered the studies by type of population studied, gonadotrophin type used for stimulation, type of agonist protocol used, type of agonist used, type of antagonist protocol used, type of antagonist used, presence of allocation concealment, presence of co-intervention and the way the information on live birth was retrieved. In conclusion, the probability of live birth after ovarian stimulation for IVF does not depend on the type of analogue used for pituitary suppression.

Female↗
PubMed2006

Batten disease: features to facilitate early diagnosis.

AIMS: To ascertain the clinical and electrophysiological features in patients with juvenile neuronal ceroid lipofuscinosis (jNCL/Batten disease) and to identify those features that facilitate early diagnosis. METHODS: Nine patients with jNCL were identified retrospectively and their case notes reviewed. All had undergone an extensive clinical examination, including electrophysiology. Blood and molecular genetic testing confirmed the diagnosis. RESULTS: Age at onset ranged from 4-8 years. At presentation, two of nine patients had normal fundi; only two of nine patients had a bull's eye maculopathy. The electroretinogram (ERG) findings in this series included undetectable rod specific ERGs, an electronegative maximal response, reduced and delayed cone flicker ERGs, reduction in the b:a ratio in the photopic single flash ERG, and an undetectable pattern ERG. Vacuolated lymphocytes on peripheral blood film testing were present in eight of nine patients. Five of eight patients were homozygous for the 1.02 kb deletion on the CLN3 gene on molecular genetic testing; two of eight patients were heterozygous for that deletion. CONCLUSION: jNCL should be considered in children of 10 years and under presenting with visual loss and fundal changes ranging from normal through to pigmentary/atrophic changes or a bull's eye maculopathy. Electrophysiology may suggest jNCL. Although currently untreatable, early diagnosis is important to institute appropriate counselling and support.

Child↗
PubMed2006

Identifying breast cancer patients at risk for Central Nervous System (CNS) metastases in trials of the International Breast Cancer Study Group (IBCSG).

BACKGROUND: We sought to determine whether a high-risk group could be defined among patients with operable breast cancer in whom a search of occult central nervous system (CNS) metastases was justified. PATIENTS AND METHODS: We evaluated data from 9524 women with early breast cancer (42% node-negative) who were randomized in International Breast Cancer Study Group clinical trials between 1978 and 1999, and treated without anthracyclines, taxanes, or trastuzumab. We identified patients whose site of first event was CNS and those who had a CNS event at any time. RESULTS: Median follow-up was 13 years. The 10-year incidence (10-yr) of CNS relapse was 5.2% (1.3% as first recurrence). Factors predictive of CNS as first recurrence included: node-positive disease (10-yr = 2.2% for > 3 N+), estrogen receptor-negative (2.3%), tumor size > 2 cm (1.7%), tumor grade 3 (2.0%), < 35 years old (2.2%), HER2-positive (2.7%), and estrogen receptor-negative and node-positive (2.6%). The risk of subsequent CNS recurrence was elevated in patients experiencing lung metastases (10-yr = 16.4%). CONCLUSION: Based on this large cohort we were able to define risk factors for CNS metastases, but could not define a group at sufficient risk to justify routine screening for occult CNS metastases.

Breast Neoplasms↗
PubMed2006

The seasonal fertility of North American bison (Bison bison) bulls.

The objective of this study was to determine the presence and magnitude of seasonal fluctuations in semen quality and other reproductive indices in bison bulls. Testicles from 288 commercially slaughtered bison bulls were collected monthly over a 1-year period. Carcass and testicle weight were determined and measurements of seminiferous tubule lumen, diameter, and epithelial thickness were made. Sperm cell morphology and defects were described and quantified using epididymal semen from each testicle. Twenty-one Plains (Bison bison bison) and Wood bison (Bison bison athabascae) breeding bulls, averaging 6.0 years of age (range 2.5-8.0), from three farms were selected for semen collection and evaluation on the basis of producer co-operation. Semen was collected by electro-ejaculation on four seasonal occasions during a 12-month period. Ejaculate quality was judged on the basis of volume, density, gross and individual motility, morphology, live/dead ratio, and concentration. Sperm cell morphologies were evaluated microscopically and classified according to criteria used for bovine semen. Fecal testosterone was measured at each semen collection using a commercial competitive binding radioimmunoassay. There was an increase in carcass weights over the study period and testis weights were moderately correlated (r=0.44) with carcass weights. However, mean testes weights were heavier (P<0.05) in the summer than in winter, spring, or fall periods. There were no differences in the proportion of normal and abnormal epididymal sperm between seasons but there were seasonal changes in the testicular parenchyma. Seminiferous tubule and lumen diameter, and epithelial thickness were greatest (P<0.05) in summer. Live bulls gained weight between April and November, but lost weight over the winter. Normal sperm cell percentages as well as individual sperm cell motility in electro-ejaculated sperm samples were higher (P<0.05) at the pre-breeding collection relative to other collections, but no change in sperm cell concentrations occurred over the study period. Fecal testosterone concentrations were highest at the pre-breeding period (June) but decreased (P<0.05) in each subsequent collection to reach their lowest levels in the April. While many changes in seen characteristics were not significant, overall results indicate the presence of some reproductive seasonality and increased testicular capacity in the summer breeding season. Bulls showing marginal semen quality in the winter but otherwise carrying desirable genetic traits may warrant another evaluation in late spring prior to being culled from a breeding program.

Animals↗
PubMed2006

Gradual formation of an operative corridor by balloon dilation for resection of subependymal giant cell astrocytomas in children with tuberous sclerosis: specialized minimal access technique of balloon dilation.

BACKGROUND: Major sources of morbidity and mortality in patients with tuberous sclerosis who develop subependymal giant cell astrocytomas (SEGAs) relate to tumor growth and resultant hydrocephalus. We describe a modification of a specialized minimal access resection technique in which an operative corridor is formed with balloon dilation over the course of a week prior to tumor resection. METHODS: Three patients with tuberous sclerosis who had an enlarging SEGA and concomitant hydrocephalus underwent surgical resection with this modified technique. A frontal craniotomy was performed and the optimal trajectory for tumor resection was confirmed by image guidance. After initial insertion of the deflated balloon into the ventricle and removal of the peel-away sheath, inflation of the balloon with a 1-mL saline injection sealed the tract. Additional 1-mL saline injections were continued during the next week until the balloon reached a 15-mm diameter, thus creating the operative corridor. One week after the first operation, the balloon was deflated and removed, and the patient underwent tumor resection via the newly formed operative corridor. RESULTS: Three patients with tuberous sclerosis underwent gross total resections of SEGAs and experienced subsequent resolution of ventricular dilation. Postoperative imaging confirmed minimal cortical disruption. CONCLUSIONS: Use of balloon dilation for the gradual formation of an operative corridor eliminated the need for additional retraction during SEGA resection, potentially decreasing injury to the surrounding neural tissue. In our three patients, the dilation tract retained its integrity during the operation and had sealed completely on postoperative imaging.

Adolescent↗
PubMed2005

Genome scan of schizophrenia families in a large Veterans Affairs Cooperative Study sample: evidence for linkage to 18p11.32 and for racial heterogeneity on chromosomes 6 and 14.

Genome-wide linkage analyses of schizophrenia have identified several regions that may harbor schizophrenia susceptibility genes but, given the complex etiology of the disorder, it is unlikely that all susceptibility regions have been detected. We report results from a genome scan of 166 schizophrenia families collected through the Department of Veterans Affairs Cooperative Studies Program. Our definition of affection status included schizophrenia and schizoaffective disorder, depressed type and we defined families as European American (EA) and African American (AA) based on the probands' and parents' races based on data collected by interviewing the probands. We also assessed evidence for racial heterogeneity in the regions most suggestive of linkage. The maximum LOD score across the genome was 2.96 for chromosome 18, at 0.5 cM in the combined race sample. Both racial groups showed LOD scores greater than 1.0 for chromosome 18. The empirical P-value associated with that LOD score is 0.04 assuming a single genome scan for the combined sample with race narrowly defined, and 0.06 for the combined sample allowing for broad and narrow definitions of race. The empirical P-value of observing a LOD score as large as 2.96 in the combined sample, and of at least 1.0 in each racial group, allowing for narrow and broad racial definitions, is 0.04. Evidence for the second and third largest linkage signals come solely from the AA sample on chromosomes 6 (LOD = 2.11 at 33.2 cM) and 14 (LOD = 2.13 at 51.0). The linkage evidence differed between the AA and EA samples (chromosome 6 P-value = 0.007 and chromosome 14 P-value = 0.004).

Adult↗
PubMed2005

Are endogenous LH levels during ovarian stimulation for IVF using GnRH analogues associated with the probability of ongoing pregnancy? A systematic review.

The aim of this systematic review was to evaluate, among women with normal ovulation or World Health Organization (WHO) II oligoanovulation who undergo ovarian stimulation for IVF using GnRH analogues, whether endogenous LH levels predict the likelihood of ongoing pregnancy beyond 12 weeks. A literature search identified six studies that answered the research question, among which two were prospective studies (one in GnRH agonist and one in GnRH antagonist cycles). None of the retrospective studies suggest that low endogenous LH levels are associated with a significantly decreased probability of ongoing pregnancy beyond 12 weeks in such patients. In the two prospective studies high endogenous LH levels during down-regulation were associated with a decreased probability of ongoing pregnancy beyond 12 weeks. Until further prospective studies modify the existing evidence summarized here, an adverse effect of low endogenous LH levels on the probability of ongoing pregnancy beyond 12 weeks is not a sensible rationale for LH supplementation during ovarian stimulation for IVF using GnRH analogues.

Female↗
PubMed2005

Resolving methodological and clinical issues in the design of efficacy trials in assisted reproductive technologies: a mini-review.

The validity, importance and relevance of randomized controlled trials depend on identifying an appropriate target population, ensuring adequate power, careful attention to the details of randomization and blinding, and selection of an endpoint that is important to the target population. With efficacy trials more than effectiveness trials, additional constraints are needed to reduce the variability that is typical of clinical practice: a narrowly defined sample, unvarying pre-randomization procedures and post-randomization treatments and follow-up that are as identical as possible for all patients. Efficacy trials comparing ovarian stimulation protocols should have strict protocol definitions, specific concomitant medications and minimal variability between centres with respect to stimulation goals and dose adjustments. Additionally, there should be narrowly defined criteria for administration of chorionic gonadotrophin, type of luteal support, embryo transfer and freezing policies. The goal of efficacy trials is to minimize the variability that is extrinsic to the comparison. When efficacy has been proven, effectiveness trials are needed to determine whether the effect of the new intervention is robust in the variability of typical clinical settings.

Adult↗
PubMed2005

Fertility and ageing.

The late 20th century trend to delay birth of the first child until the age at which female fecundity or reproductive capacity is lower has increased the incidence of age-related infertility. The trend and its consequences have also stimulated interest in the possible factors in the female and the male that may contribute to the decline in fecundity with age; in the means that exist to predict fecundity; and in the consequences for pregnancy and childbirth. In the female, the number of oocytes decreases with age until the menopause. Oocyte quality also diminishes, due in part to increased aneuploidy because of factors such as changes in spindle integrity. Although older male age affects the likelihood of conception, abnormalities in sperm chromosomes and in some components of the semen analysis are less important than the frequency of intercourse. Age is as accurate as any other predictor of conception with assisted reproductive technology. The decline in fecundity becomes clinically relevant when women reach their mid-30s, when even assisted reproduction treatment cannot compensate for the decline in fecundity associated with delaying attempts at conceiving. Pregnancies among women aged >40 years are associated with more non-severe complications, more premature births, more congenital malformations and more interventions at birth.

Adult↗
PubMed2005

Timing of CMF chemotherapy in combination with tamoxifen in postmenopausal women with breast cancer: role of endocrine responsiveness of the tumor.

BACKGROUND: Controversy persists about whether chemotherapy benefits all breast cancer patients. PATIENTS AND METHODS: In the International Breast Cancer Study Group (IBCSG) trial VII, 1212 postmenopausal patients with node-positive disease were randomized to receive tamoxifen for 5 years or tamoxifen plus three concurrent courses of cyclophosphamide, methotrexate and 5-fluorouracil ('classical' CMF) chemotherapy, either early, delayed or both. In IBCSG trial IX, 1669 postmenopausal patients with node-negative disease were randomized to receive either tamoxifen alone or three courses of adjuvant classical CMF prior to tamoxifen. Results were assessed according to estrogen receptor (ER) content of the primary tumor. RESULTS: For patients with node-positive, ER-positive disease, adding CMF either early, delayed or both reduced the risk of relapse by 21% (P=0.06), 26% (P=0.02) and 25% (P=0.02), respectively, compared with tamoxifen alone. There was no difference in disease-free survival when CMF was given prior to tamoxifen in patients with node-negative, ER-positive tumors. CONCLUSIONS: CMF given concurrently (early, delayed or both) with tamoxifen was more effective than tamoxifen alone for patients with node-positive, endocrine-responsive breast cancer, supporting late administration of chemotherapy even after commencement of tamoxifen. In contrast, sequential CMF and tamoxifen for patients with node-negative, endocrine-responsive disease was ineffective.

Adult↗
PubMed2005

Single-photon emission computed tomography perfusion imaging in the differential diagnosis of dementia: a retrospective regional audit.

A retrospective audit of (99m)Tc-HMPAO SPECT scans was undertaken to assess the utility of brain perfusion imaging in a cohort of young cognitively impaired patients in whom diagnostic uncertainty remained after standard clinical and neuropsychological assessment and structural brain imaging. SPECT scans were assessed by five raters (two neurologists and three nuclear medicine specialists) on two occasions 6 months apart, first without any clinical data and second with brief pertinent clinical information. SPECT diagnoses were compared with criterion diagnoses subsequently established by the two neurologists with access to all clinical, neuropsychological and neuroimaging data. Despite reasonable intra- and interrater reliability, diagnostic accuracy ranged from 32 to 58%. SPECT scan normality or abnormality in blind and informed viewings gave respective sensitivities of 77 and 71%, specificities of 44 and 38%, positive predictive values of 88 and 87% and negative predictive values of 27 and 18%. Calculating pairwise disease group comparisons, likelihood ratios suggested some diagnostic gain in differentiating AD from 'not AD' and from FTD/focal syndromes. SPECT scanning was of little help in establishing diagnoses in this cohort of patients, a finding which supports the conclusion of the American Academy of Neurology evidence-based review that SPECT imaging cannot be recommended for either the initial or the differential diagnosis of suspected dementia because it has not demonstrated superiority to clinical criteria.

Adult↗
PubMed2005

Quality of care for women presenting with benign breast conditions.

The aim of the study was to investigate the management of women with benign breast problems. A consecutive sample of women (n = 194) was assessed who presented to public or private sector providers. The main reasons for referral were breast lumps (62%); 56% of women who attended the public sector did not receive any recommendation compared to 40% who attended the private sector and clinical/general practitioner reviews were recommended to more women in the private sector (54%). Reasons for the discrepancy between public and private patients require further investigation.

Australia↗
PubMed2004

Quantifying trade-offs: quality of life and quality-adjusted survival in a randomised trial of chemotherapy in postmenopausal patients with lymph node-negative breast cancer.

We evaluated quality of life (QL) and quality-adjusted survival in International Breast Cancer Study Group Trial IX, a randomised trial including 1669 eligible patients receiving tamoxifen for 5 years or three prior cycles of cyclophosphamide, methotrexate and 5-fluorouracil (CMF) followed by 57 months tamoxifen. During the time with CMF toxicity (Tox), without symptoms and toxicity (TWiST), and following relapse (Rel), patients scored their QL indicators and a utility indicator for subjective health estimation between 'perfect' and 'worst' health. Scores were averaged within Tox, TWiST and Rel and transformed to utilities. Mean durations for the three transition times were weighted with utilities to obtain mean quality-adjusted TWiST (Q-TWiST). Patients receiving CMF reported significantly worse scores for most QL domains at month 3, but less hot flushes. After completing chemotherapy, there were no differences by treatment groups. Benefits evaluated by Q-TWiST favoured the additional chemotherapy. CMF provided 3 more months of Q-TWiST for patients with ER-negative tumours, but CMF provided no benefit in Q-TWiST for patients with ER-positive tumours. Q-TWiST analysis based on patient ratings is feasible in large-scale cross-cultural clinical trials.

Adult↗
PubMed2004

Impacts of dredged material disposal on a tropical soft-bottom benthic assemblage.

The soft-bottom benthic macrofauna in a spoil-ground of dredged material in Cleveland Bay, North Queensland, Australia, was studied to detect possible impacts of the disposal of sediments. The spatial distribution of the assemblage was studied in relation to the source of the impact at 28 stations on four occasions during 1998 and 1999. Additionally, environmental variables were measured on each occasion at each station. Macrobenthic assemblages inside the spoil-ground were different from assemblages outside the spoil ground only immediately after (15 days) the disposal of dredged material. Given the decrease in the abundance of organisms and number of species, it is suggested that this effect was due to direct burial of the macrobenthic assemblage inside the spoil-ground. Macrobenthic assemblages inside the spoil ground were not different from assemblages outside the spoil ground 3 months after dumping. These results suggest that the soft-bottom macrobenthic assemblages may respond quickly to the disturbance associated with the dumping of dredged material.

Animals↗
PubMed2004

Body mass index as a prognostic feature in operable breast cancer: the International Breast Cancer Study Group experience.

BACKGROUND: Current information on the prognostic importance of body mass index (BMI) for patients with early breast cancer is based on a variety of equivocal reports. Few have data on BMI in relationship to systemic treatment. PATIENTS AND METHODS: Patients (6792) were randomized to International Breast Cancer Study Group trials from 1978 to 1993, studying chemotherapy and endocrine therapy. BMI was evaluated with eight other factors: menopausal status, nodal status, estrogen receptor status, progesterone receptor status, tumor size, vessel invasion, tumor grade and treatment. BMI was categorized as normal (< or =24.9), intermediate (25.0-29.9) or obese (> or =30.0). RESULTS: Patients with normal BMI had significantly longer overall survival (OS) and disease-free survival (DFS) than patients with intermediate or obese BMI in pairwise comparisons adjusted for other factors. Subset analyses showed the same effect in pre- and perimenopausal patients and in those receiving chemotherapy alone. When assessed globally and adjusted for other factors, BMI significantly influenced OS (P = 0.03) but not DFS (P = 0.12). CONCLUSIONS: BMI is an independent prognostic factor for OS in patients with breast cancer, especially among pre-/perimenopausal patients treated with chemotherapy without endocrine therapy.

Aged↗
PubMed2004

Towards less confusing terminology in reproductive medicine: a proposal.

The use of the term "infertility" and related terms in reproductive medicine is reviewed. Current terminology is found to be ambiguous, confusing and misleading. We recommend that the fertility investigation report of a couple should consist of statements concerning description, diagnosis and prognosis. The description concerns the duration of non-pregnancy before consulting the clinician. A system for prognostic grading is proposed. The fertility investigation report forms the basis for further action, including the possibility of waiting with treatment in case of almost normal or only slightly reduced fertility. The use of the terms infertility, subfertility and fecundity is not necessary, and it is recommended to avoid them.

Humans↗