Biomedical subjects

M Collins

Publications and source records attributed to M Collins.

At least 37 records · Page 2Linked to original sources

PubMed2003

Exploring core relationships between insight and communication and social skills in mentally disordered offenders.

This paper reports collective data analysis for the Behavioural Status Index insight and communication and social skills subscales. This is an instrument designed specifically for health care practitioners to measure behavioural and social functioning among mental health clients, in particular those in forensic care. Data were collected, using a repeated measures method by primary nurses, from a sample of 503 patients in two high security mental health hospitals in the UK. Results are reported for interscalar item correlations and factor analysis. Data trends are indicative of clinically interesting relationships. A six-factor structure emerged suggesting groupings of intra- and interscalar behaviours. The first of these contained all the Behavioural Status Index insight items. Significant differences were found on a number of factors between independent groups. Generally, results indicate that patients on lower dependency wards scored more normatively on the factors, adding to instrument validity. Men were found to score more normatively than women. According to Mental Health Act 1983 classifications, psychopathically disordered patients scored more normatively than mentally ill patients, who in turn scored more normatively than patients with learning disability. Clinical practice implications and ongoing European studies examining the use of the instrument in clinical practice and its association to treatment planning are discussed.

Attitude to Health↗

PubMed2002

Complete genome sequence of the model actinomycete Streptomyces coelicolor A3(2).

Streptomyces coelicolor is a representative of the group of soil-dwelling, filamentous bacteria responsible for producing most natural antibiotics used in human and veterinary medicine. Here we report the 8,667,507 base pair linear chromosome of this organism, containing the largest number of genes so far discovered in a bacterium. The 7,825 predicted genes include more than 20 clusters coding for known or predicted secondary metabolites. The genome contains an unprecedented proportion of regulatory genes, predominantly those likely to be involved in responses to external stimuli and stresses, and many duplicated gene sets that may represent 'tissue-specific' isoforms operating in different phases of colonial development, a unique situation for a bacterium. An ancient synteny was revealed between the central 'core' of the chromosome and the whole chromosome of pathogens Mycobacterium tuberculosis and Corynebacterium diphtheriae. The genome sequence will greatly increase our understanding of microbial life in the soil as well as aiding the generation of new drug candidates by genetic engineering.

Bacterial Proteins↗

PubMed2002

The genome sequence of Schizosaccharomyces pombe.

We have sequenced and annotated the genome of fission yeast (Schizosaccharomyces pombe), which contains the smallest number of protein-coding genes yet recorded for a eukaryote: 4,824. The centromeres are between 35 and 110 kilobases (kb) and contain related repeats including a highly conserved 1.8-kb element. Regions upstream of genes are longer than in budding yeast (Saccharomyces cerevisiae), possibly reflecting more-extended control regions. Some 43% of the genes contain introns, of which there are 4,730. Fifty genes have significant similarity with human disease genes; half of these are cancer related. We identify highly conserved genes important for eukaryotic cell organization including those required for the cytoskeleton, compartmentation, cell-cycle control, proteolysis, protein phosphorylation and RNA splicing. These genes may have originated with the appearance of eukaryotic life. Few similarly conserved genes that are important for multicellular organization were identified, suggesting that the transition from prokaryotes to eukaryotes required more new genes than did the transition from unicellular to multicellular organization.

Base Sequence↗

PubMed2002

Actinobacillus pleuropneumoniae serotype 1 carrying the defined aroA mutation is fully avirulent in the pig.

The aroA gene from Actinobacillus pleuropneumoniae serotype 1 reference strain 4074 was isolated and sequenced. The gene complemented the aroA mutation in Escherichia coli AB2829. A kanamycin resistance cassette was inserted into the aroA gene and the mutant gene was reintroduced into A. pleuropneumoniae by allelic replacement. Intratracheal infection of susceptible pigs with A. pleuropneumoniae aroA caused no signs of respiratory disease or lung lesions in any of the animals at a dose 10(4) times the dose reliably known to induce acute pleuropneumonia; all animals infected with the unaltered control strain developed acute disease. The aroA mutant was rapidly eliminated from the lungs and tonsil of infected animals. The mutant may represent a safely attenuated strain for use in live bacterial vaccination or the delivery of antigen by the intranasal route. However, the residence time of the mutant in the respiratory tract of the pig may be too short for it to be useful in generating a protective immune response.

3-Phosphoshikimate 1-Carboxyvinyltransferase↗

PubMed2001

Microfocus small angle X-ray scattering reveals structural features in archaeological bone samples: detection of changes in bone mineral habit and size.

Microfocus X-ray scattering provides a powerful nondestructive technique capable of providing important information about the size, habit, and arrangement of mineral crystals in bone. The technique is capable of probing textural differences in a sample at a micron scale resolution. The study presented here involved the analysis of a number of archaeological bones by microfocus X-ray scattering at the ESRF Grenoble in order to determine local changes in mineral durability. The results showed that regions of bone with a modified microscopic morphology contained a greater dispersion of crystal shape when compared with more intact regions and control contemporary bone samples, but the crystal thickness values showed similar consistency. We speculate that the persistence of collagen in the archaeological bone may allow diagenetic remodeling of bone in terms of crystallite shape but defines the size of remodelled crystallites. The ability to detect such local changes in texture has wide potential for determining crystal characteristics in healthy and diseased bone samples.

Archaeology↗

PubMed2001

Anti-human immunodeficiency virus drugs are ineffective against Pneumocystis carinii in vitro and in vivo.

Human immunodeficiency virus (HIV) protease inhibitors (PIs) recently have been reported to be active against Pneumocystis carinii in cell culture. Twelve anti-HIV drugs were analyzed for their effects against rat P. carinii by an ATP cytotoxicity assay. Indinavir and saquinavir exhibited slight anti-P. carinii activity at concentrations above those that can be clinically achieved in serum; other PIs and nucleoside and nonnucleoside reverse-transcriptase inhibitors were inactive against the organism. Anti-HIV drugs, alone or in combination, did not materially reduce the organism count in the treatment of P. carinii pneumonia in immunosuppressed mice. Thus, anti-HIV drugs have little or no activity against P. carinii in these in vitro and in vivo systems. Caution should be used when interpreting reports of the susceptibility of P. carinii to anti-HIV drugs on the basis of in vitro testing only.

Administration, Oral↗

PubMed2001

Risk factors for meningococcal disease in college students.

CONTEXT: Elevated rates of meningococcal disease were noted among 18- to 22-year-olds in the mid-1990s. However, national data on rates of meningococcal disease in US college students were not collected until 1998. OBJECTIVES: To determine rates of meningococcal disease in US college students and to identify risk factors for meningococcal disease in this population. DESIGN, SETTING, AND PATIENTS: Prospective surveillance study with nested case-control study of US college students with meningococcal infection from September 1, 1998, to August 31, 1999. Fifty state health departments and 231 college health centers participated. MAIN OUTCOME MEASURES: Incidence of and risk factors for meningococcal disease in US college students. RESULTS: Ninety-six cases of meningococcal disease were identified. The incidence rate for undergraduates was 0.7 per 100 000 persons vs 1.4 per 100 000 for the general population of 18- to 23-year-old nonstudents (P<.001). Freshmen living in dormitories had the highest incidence rate at 5.1 per 100 000. Of the 79 case-patients for whom information was available, 54 (68%) had illness due to vaccine-preventable meningococcal serogroups. On multivariable analysis of case-control study data, freshmen who lived in dormitories had an elevated risk of meningococcal disease (matched odds ratio, 3.6; 95% confidence interval, 1.6-8.5; P =.003) compared with other college students. CONCLUSIONS: Freshmen who live in dormitories have an independent, elevated risk of meningococcal disease compared with other college students. Use of the currently available quadrivalent polysaccharide vaccine among college students could substantially decrease their risk of meningococcal disease.

Adolescent↗

PubMed2001

Differential expression of inducible costimulator-ligand splice variants: lymphoid regulation of mouse GL50-B and human GL50 molecules.

The process of immunological costimulation between APC and T cells is mediated by protein ligand:receptor interactions. To date, costimulatory receptors known to be expressed by T cells include the structurally related proteins CD28 and the inducible costimulator (ICOS). The ligands to human and mouse ICOS, human GL50 (hGL50), and mouse GL50 (mGL50) were recently cloned and demonstrated to have sequence similarity to the CD28 ligands B7-1 and B7-2. Examination of mGL50 cDNA transcripts by 3'RACE revealed an alternatively spliced form, mGL50-B, that encoded a protein product with a divergent 27-aa intracellular domain. Both mGL50- and mGL50-B-transfected cells exhibited binding to human and mouse ICOS-Ig fusion protein, indicating that the alternate cytoplasmic domain of mGL50-B does not interfere with extracellular interactions with ICOS receptor. Flow cytometric and RT-PCR analysis of BALB/c and RAG1(-/-) mice splenocytes demonstrate that freshly isolated B cells, T cells, macrophages, and dendritic cells express both splice variant forms of ICOS ligand. Comparative analyses with the human ICOS ligand splice variants hGL50 and B7-H2 indicate that differential splicing at the junction of cytoplasmic exon 6 and exon 7 may be a common method by which GL50-ICOS immunological costimulatory processes are regulated in vivo.

Alternative Splicing↗

PubMed2001

The combination of chemotherapy and systemic immunotherapy with soluble B7-immunoglobulin G leads to cure of murine leukemia and lymphoma and demonstration of tumor-specific memory responses.

Major mechanisms underlying poor immune responses to autologous tumor-associated antigens are overwhelming tumor kinetics and the absence of effective T-cell costimulation by antigen-presenting cells. To address these issues, leukemia and lymphoma mice were treated with the combination of chemotherapy and systemic immunotherapy with recombinant soluble murine B7-immunoglobulin G (IgG) molecules. In this report, 3 murine models were used, a radiation-induced SJL acute myeloid leukemia, a transplantable spontaneous SJL lymphoma, and the C57BL/6 EL-4 thymic lymphoma. Various treatment modalities were evaluated: single treatments with either B7-IgG or chemotherapy as well as combination therapies. The results demonstrate the following: (1) in all tumor models, the combination of chemotherapy and soluble B7-IgGs is more potent than either therapy alone, leading to cure of tumor-bearing animals; (2) the therapeutic responses are T-cell-dependent, because combined therapy is not efficacious in severe combined immunodeficient mice; (3) the rejection of tumor cells leads to the development of tumor-specific immunity, because cured mice are immune to the rejected tumor but not to a different syngeneic tumor; and (4) (51)Cr release assays show that rejection of tumor cells leads to the development of very potent tumor-specific cytotoxic T-lymphocyte activity. On the basis of these results, it is proposed that chemotherapy-mediated tumor reduction, together with consequent augmented tumor-antigen presentation to activated T cells, are primary mechanisms leading to curative responses. The safety profile of the B7-IgG fusion proteins and their synergy with chemotherapy strongly suggest that the combination regimen is a promising strategy in cancer treatment.

Acute Disease↗

PubMed2001

Brachytherapy for in-stent restenosis through the internal mammary artery.

We report five cases treated with brachytherapy through the internal mammary artery (IMA) for in-stent restenosis at the distal anastomosis (n = 3) and in the left anterior descending coronary artery beyond the distal anastomosis (n = 2). After angioplasty, catheter-based gamma radiation was performed. There was no delivery failure of the radiation system. All cases had angiographic success and no procedural or in-hospital complications.

Aged↗

PubMed2001

Assembly and annotation of human chromosome 2q33 sequence containing the CD28, CTLA4, and ICOS gene cluster: analysis by computational, comparative, and microarray approaches.

Human chromosome 2q33 is an immunologically important region based on the linkage of numerous autoimmune diseases to the CTLA4 locus. Here, we sequenced and assembled 2q33 bacterial artificial chromosome (BAC) clones, resulting in 381,403 bp of contiguous sequence containing genes encoding a NADH: ubiquinone oxidoreductase, the costimulatory receptors CD28, CTLA4, and ICOS, and a HERV-H type endogenous retrovirus located 366 bp downstream of ICOS in the reverse orientation. Genomic microarray expression analysis using differentially activated T-cell RNA against a subcloned CTLA4/ICOS BAC library revealed upregulation of CTLA4 and ICOS sequences, plus antisense ICOS transcripts generated by the HERV-H, suggesting a potential mechanism for ICOS regulation. We identified four nonlinked, polymorphic, simple repetitive sequence elements in this region, which may be used to delineate genetic effects of ICOS and CTLA4 in disease populations. Comparative genomic analysis of mouse genomic Icos sequences revealed 60% sequence identity in the 5' UTR and regions between exon 2 and the 3' UTR, suggesting the importance of ICOS gene function.

Abatacept↗

PubMed2001

Effect of sildenafil in patients with erectile dysfunction taking antihypertensive therapy. Sildenafil Study Group.

Oral sildenafil is an effective treatment for erectile dysfunction (ED), which is a common complaint for patients with hypertension and those taking antihypertensive agents. This post hoc subanalysis assessed the efficacy and safety of sildenafil in men with ED who were receiving concomitant antihypertensive medication. Efficacy was assessed in 3414 men (1218 of whom were taking antihypertensive medication) who received sildenafil (5 to 200 mg) or placebo for 6 weeks to 6 months in 10 double-blind, placebo-controlled studies. The significant improvements in erectile function demonstrated by sildenafil-treated patients were comparable in patients taking and those not taking antihypertensive medication. Safety was assessed in 3975 men (1094 of whom were taking one or more antihypertensive agent, classified as a diuretic, beta-blocker, alpha1-blocker, angiotensin converting enzyme inhibitor, or calcium channel blocker), who received sildenafil or placebo in 18 double-blind, placebo-controlled studies. For patients taking sildenafil and antihypertensive medication, the incidence of treatment-related adverse events (34%) was similar to that for sildenafil-treated patients not taking any antihypertensive agent (38%). The incidences of the most common adverse events and of adverse events potentially related to blood pressure decreases (eg, hypotension, dizziness, and syncope) were similar in both sildenafil groups. The number of antihypertensive medications taken from among the five classes had no effect on the adverse event profile of sildenafil. Sildenafil is an effective and well-tolerated treatment for ED in patients taking concomitant antihypertensive medication, including those on multidrug regimens.

Adult↗

PubMed2001

11C-methionine PET imaging of leptomeningeal metastases from primary breast cancer--a case report.

Leptomeningeal metastases (LM) is often an elusive disease frequently diagnosed at an advanced clinical stage. Early diagnosis may allow for prompt initiation of treatment with minimal tumor burden and maximal chance of survival, especially in solid tumors such as breast cancer. Although the method of choice for imaging LM currently is by gadolinium enhanced magnetic resonance imaging (MRI), the technique has a high sensitivity but low specificity. We report the first case of Carbon 11-labelled methionine (Cmet) positron emission tomography (PET) imaging of leptomeningeal metastases in a patient with primary breast cancer. This patient presented with clinical features suggestive of LM, but had inconclusive cerebrospinal fluid (CSF) findings. Although, the contrast enhanced MRI revealed calvarial and meningeal lesions, it is known that meningeal enhancement on MRI does not always indicate metastases. In this clinical dilemma the strong methionine uptake on PET helped steer the diagnosis in favor of cancerous infiltration even before the CSF cytology became positive for malignancy.

Breast Neoplasms↗

PubMed2001

The effect of monochromatic aberrations on Autoref R-1 readings.

The Canon Autoref R-1 is used extensively to investigate aspects of the accommodation response of the human eye. The measurement zone of the Autoref R-1 is known to lie outside the central pupil and the instrument's readings are therefore potentially influenced by the monochromatic aberrations of the eye. Since these aberrations are known to change as a function of accommodation, the error associated with the aberrations might influence the stimulus-response slope. We used masks and contact lenses with known amounts of spherical aberration to establish the region of the pupil used by the Autoref R-1 in deriving a reading of the refractive power of the eye. This region was estimated to be narrowly centred on a 3.5-mm diameter. The spherical aberration of the eye was measured for five subjects across a range of accommodation levels and used to predict the likely effect upon Autoref R-1 readings. Positive spherical aberration will result in an apparent lead of accommodation, while negative spherical aberration causes an apparent lag of accommodation. For eyes with normal levels of spherical aberration, the slope of the stimulus-response will appear to be marginally flatter when measured with the Autoref R-1. An example of an eye with coma-like aberrations is also shown to produce Autoref R-1 results that will differ significantly from more central refractive measurements.

Accommodation, Ocular↗

PubMed2001

African American children's ability to identify emotion in facial expressions and tones of voice of European Americans.

This study examined whether African American children's ability to identify emotion in the facial expressions and tones of voice of European American stimuli was comparable to their European American peers and related to personality, social competence, and achievement. The Diagnostic Analysis of Nonverbal Accuracy (DANVA ; Nowicki & Duke, 1994) was administered to 84 African American children. It was found that they performed less accurately on adult and child tones of voice and adult facial expressions. Further, girls' ability to read emotion in tones of voice was related to better social competence and achievement, whereas boys' ability to identify emotion in adult tones of voice was related to teacher-rated social competence. Results suggest that more research is needed with ethnic groups to clarify the impact of nonverbal processing skills on social and achievement outcomes.

Achievement↗

PubMed2001

Right hemisphere contributions to the comprehension of low-imagery words.

A priming experiment, with normal university students as subjects, was used to investigate whether the right cerebral hemisphere contributes to the comprehension of low-imagery words. Each hemisphere's access to semantic representations of low-imagery words was gauged by comparing responses to low-imagery targets preceded by associated low-imagery primes (e.g., BELIEF-IDEAL) with responses to the same targets when they were preceded by unrelated primes (e.g., FATE-IDEAL). All primes and targets were independently projected to the left or right visual fields (LVF or RVF), and temporally separated by a stimulus onset asynchrony of 250 ms. There was a clear RVF advantage in response speed and accuracy measures, confirming the left hemisphere's advantage in processing low-imagery words. Nonetheless, the priming effects provided evidence that the right hemisphere contributes to the comprehension of low-imagery words, as primes projected to the RVF equally facilitated responses to associated targets subsequently appearing in either visual field. In contrast, primes directed to the LVF did not facilitate responses to associated targets projected to the LVF or RVF. The results suggest that low-imagery words projected to the left hemisphere activated low-imagery associates in both hemispheres to an equivalent degree, whereas low-imagery primes directed to the right hemisphere failed to activate low-imagery associates in either hemisphere. Like Kounios and Holcomb's (1994) study of event-related response potentials evoked by abstract and concrete words, the findings indicate that while the left hemisphere is the primary processor of low-imagery/abstract words, the right hemisphere plays a subsidiary role in the comprehension of these words.

Journal Article↗

PubMed2001

Sildenafil citrate (VIAGRA) improves erectile function in elderly patients with erectile dysfunction: a subgroup analysis.

BACKGROUND: The prevalence of erectile dysfunction (ED) increases with advancing age, with a particularly high prevalence of ED in elderly patients with diabetes. In the United States it is estimated that approximately 45% of men aged 65 to 69 years have moderate or complete ED. The efficacy and safety of oral sildenafil (VIAGRA) for treating ED in elderly men (aged > or = 65 years or older) were assessed. METHODS: We analyzed data obtained from five double-blind, placebo-controlled studies of the efficacy and tolerability of oral sildenafil taken as required (but not more than once daily) over a 12-week to 6-month period. Two subgroups were evaluated: (i) elderly patients with ED of broad-spectrum etiology (n = 411), and (ii) elderly patients with ED and diabetes (n = 71). Efficacy was assessed using a global efficacy question, questions 3 and 4 of the International Index of Erectile Function (IIEF). and the five sexual function domains of the IIEF. RESULTS: All efficacy assessments indicated that sildenafil significantly improved erectile function both in elderly patients with ED of broad-spectrum etiology and in elderly patients with ED and diabetes. The most common adverse events were mild-to-moderate headache, flushing, and dyspepsia. The rates of discontinuation due to adverse events were low and were comparable to the rates with placebo. CONCLUSIONS: Sildenafil is an efficacious and well-tolerated treatment for ED in elderly men.

Aged↗

PubMed2001

In vitro and in vivo effects of quinupristin-dalfopristin against Pneumocystis carinii.

Quinupristin-dalfopristin (Q-D), which is active against bacteria and Toxoplasma gondii, was examined for its activity against Pneumocystis carinii. After 72 h of incubation with rat P. carinii in an ATP cytotoxicity assay, the 50% inhibitory concentration of Q-D was 10.6 microg/ml, a level that can be achieved in serum with high-dose administration. Q-D administered intraperitoneally at doses of 50 to 200 mg per kg of body weight per day in the treatment and 100 mg/kg/day three times per week in the prophylaxis of pneumocystosis in immunosuppressed mice reduced the organism burden up to 15- and 302-fold, respectively. We conclude that Q-D has activity against P. carinii in vitro and in vivo.

Adenosine Triphosphate↗