PubMed Health⌕ Search

Biomedical subjects

James Morris

Publications and source records attributed to James Morris.

16 recordsLinked to original sources
PubMed2006

Opinion formation in evaluating the adjudicative competence and restorability of criminal defendants: a review of 8,000 evaluations.

Evaluations of competence to stand trial (CST) are the most common type of criminal forensic evaluation conducted, and courts tend to defer to clinician opinions regarding a defendant's competence. Thus, it is important to study the ways in which clinicians arrive at opinions regarding adjudicative competence and the data they consider in forming their opinions. We reviewed 8,416 evaluations conducted by forensic evaluators in Virginia over a 12 year period, and examined (a) the clinical, demographic, and criminal characteristics of a defendant as related to opinions regarding competence, predicted restorability, and impairment on "prongs" of the Dusky standard, (b) process and outcome differences in evaluations conducted by psychiatrists versus psychologists and inpatient versus outpatient evaluators, and (c) the consistency of incompetence base rates over a 10 year period. Overall, clinicians opined that 19% of defendants were incompetent and considered 23% of these unlikely to be restored to competence. Not surprisingly, psychotic and organic/intellectual disorders were most strongly associated with findings of incompetence. However, there were some notable differences between evaluations by psychologists versus psychiatrists and between evaluations conducted in inpatient versus outpatient settings.

Adult↗
PubMed2005

The treatment of primary central nervous system lymphoma in 122 immunocompetent patients: a population-based study of successively treated cohorts from the British Colombia Cancer Agency.

BACKGROUND: The objective of this study was to evaluate the clinical outcome of a population-based cohort of immunocompetent patients with primary central nervous system lymphoma (PCNSL) treated with 3 different strategies over 13 years. METHODS: One hundred twenty-two consecutive patients (median age, 66 years) with PCNSL were identified. Three treatment strategies were employed: 1) whole-brain irradiation with (from January, 1990, to June, 1991) or without (from April, 1995, to December, 1999) cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP)-type chemotherapy (n=50 patients); 2) combined-modality therapy, including 1 g/m2 methotrexate plus whole-brain irradiation (from July, 1991, to March, 1995; n=34 patients); and 3) 8 g/m2 methotrexate alone (from January, 2000, to March, 2003) with whole-brain irradiation reserved for those with progressive disease (n=38 patients). Treatment failure was defined as progressive disease, disease recurrence, death from toxicity or lymphoma, or toxicity that necessitated a change in primary treatment. RESULTS: The median failure-free survival was 7 months, and the median overall survival (OS) was 17 months. The median OS was similar in all 3 eras. In this population-based analysis, one-third of patients did not receive the treatment strategy of the era. Therefore, the data also were analyzed by treatment received. On multivariate analysis (including era of treatment), 3 factors-age > 60 years, lactate dehydrogenase > normal, and omission of methotrexate-were associated significantly with poorer OS (hazard ratio: 2.3, 2.2, and 2.3, respectively). CONCLUSIONS: Outcomes for a general population with PCNSL remained constant despite different treatment strategies over three eras. For the two-thirds of patients who could receive potentially curative treatment, age, lactate dehydrogenase level, and receipt of > or = 1 g/m2 methotrexate appeared to be important determinants of OS.

Adult↗
PubMed2005

3D needle-tissue interaction simulation for prostate brachytherapy.

This paper presents a needle-tissue interaction model that is a 3D extension of a prior work based on the finite element method. The model is also adapted to accommodate arbitrary meshes so that the anatomy can effectively be meshed using third-party algorithms. Using this model a prostate brachytherapy simulator is designed to help medical residents acquire needle steering skills. This simulation uses a prostate mesh generated from clinical data segmented as contours on parallel slices. Node repositioning and addition, which are methods for achieving needle-tissue coupling, are discussed. In order to achieve realtime haptic rates, computational approaches to these methods are compared. Specifically, the benefit of using the Woodbury formula (matrix inversion lemma) is studied. Our simulation of needle insertion into a prostate is shown to run faster than 1 kHz.

Brachytherapy↗
PubMed2005

Influenza treatment with neuraminidase inhibitors: cost-effectiveness and cost-utility in healthy adults in the United Kingdom.

We assessed the cost-effectiveness and cost-utility of treating influenza with neuraminidase inhibitors (oseltamivir and zanamivir) from a health care payer's and societal perspective in the United Kingdom. A simulation model was developed to predict morbidity and mortality due to influenza and its specified complications, comparing neuraminidase inhibitors with usual care in an otherwise healthy adult population. Robustness of the results was tested by one-way and multiway as well as probabilistic sensitivity analyses. Treatment with either neuraminidase inhibitor results in reduced morbidity and faster return to normal activities. However, oseltamivir dominates zanamivir in cost-utility analysis due to its lower costs. Comparing oseltamivir with usual care, the costs are pound14.36 per day of normal activity gained and pound5,600 per quality-adjusted life-year gained from the healthcare payer perspective. Oseltamivir dominates usual care from the societal perspective. Treatment with oseltamivir is a cost-effective strategy for otherwise healthy adults in the UK from both the healthcare payer and societal perspective.

Acetamides↗
PubMed2005

Computing intraoperative dosimetry for prostate brachytherapy using TRUS and fluoroscopy.

RATIONALE AND OBJECTIVES: There is a need to provide real-time dosimetric feedback during prostate brachytherapy based on the location of the implanted seeds. The objective of our approach is to develop a system to accurately locate seeds with minimal impact on the current protocol for prostate brachytherapy and without additional imaging equipment. MATERIALS AND METHODS: A new approach for intraoperatively computing dosimetry for prostate brachytherapy is presented. The approach uses transrectal ultrasound (TRUS) and fluoroscopic images. A fluoroscopic image of the TRUS probe is required to register the fluoroscopic and ultrasound images. The C-arm is not moved during the procedure and all images are acquired from the same C-arm angles. A needle path is interpolated for each needle based on the location of the needle tip in TRUS images and the known entry point of the needle. Throughout the procedure, fluoroscopic images are acquired to determine the coronal plane coordinates of the seeds and the remaining coordinate of each seed is computed from the needle path. For accurate results, intraoperative seed motion tracking is advised and a method to achieve such tracking is also presented. RESULTS: Experimentally, the TRUS and fluoroscopic images are registered with a mean and maximum error of 1.3 mm and 5.8 mm, respectively. In a phantom, 12 seeds are located using our approach and compared with the known locations, with a mean error in the x, y, and z direction of 0.96 mm, 0.33, and 0.68 mm, respectively, and a corresponding maximum error of 1.85 mm, 0.56 mm, and 1.63 mm. Experimental results show motion tracking in the y-direction with submillimeter accuracy. The feasibility of our approach is tested on five cases of clinical data using a semiautomated version of our system and the resulting dosimetry is compared with that found using postoperative computed tomography images. The D90 and V100 metrics computed using our approach and the computed tomography images differ by a maximum of 16.6% and 1.7%, respectively. CONCLUSIONS: TRUS can be combined with single pose fluoroscopic images to compute delivered dose intraoperatively for prostate brachytherapy. Phantom results demonstrate the accuracy of the method and preliminary clinical results show its potential.

Brachytherapy↗
PubMed2005

Urinary incontinence in prostate cancer patients treated with external beam radiotherapy.

BACKGROUND AND PURPOSE: To describe the incidence of urinary incontinence among prostate cancer patients treated with external beam radiotherapy (RT) and to investigate associated risk factors. PATIENTS AND METHODS: One thousand and hundred ninety-two patients with >or=24 months follow-up were the subjects of this series. All patients received between 50 and 72 Gy in 20-37 fractions (median 66 Gy/33#). Post-RT urinary incontinence was scored by direct patient interviewing according to the modified RTOG/SOMA scale: Grade 1--occasional use of incontinence pads, Grade 2--intermittent use of incontinence pads, Grade 3--persistent use of incontinence pads, and Grade 4--permanent catheter. Risk-factors investigated were: age, diabetes, TURP prior to RT, elapsed time from TURP to RT, clinical stage, RT dose and presence of Grade >or=2 acute GU and GI toxicity. Non-parametric, actuarial univariated (Kaplan-Meier) and multivariated tests (MVA, Cox regression) were performed. RESULTS: Median follow-up for the group is 52 months (24-109). Thirty-four patients (2.9%) had incontinence prior to RT, which was more common in TURP patients (7.8% vs 1.6% P<0.001). These are excluded from further analysis. Fifty-seven patients (4.9%) developed Grade 1 incontinence, 7 (0.6%) Grade 2, and 7 (0.6%) Grade 3. There was no Grade 4 incontinence. Actuarial rates for Grade >or=1 and >or=2 incontinence at 5 years are 7 and 1.7%, respectively. Risk factors on MVA associated with the development of Grade 1 or worse incontinence are pre-RT TURP (5-year rates 10% vs 6%, P=0.026), presence of Grade >or=2 acute GU toxicity (5-year rates 11% vs 5%, P=0.002). Age, diabetes, clinical stage, elapsed time from TURP to RT, RT dose or fraction size, acute GI toxicity were not significant. Patients who underwent post-RT TURP or dilatation for obstructive symptoms (4.3%), were more likely to develop Grade 2-3 incontinence (5-year rate 8 vs 1.5%, P=0.0015). CONCLUSIONS: Grade 2 or greater urinary incontinence is rare among patients who have been treated with external beam radiotherapy. Associated risk factors are pre-RT TURP and the presence of increased acute GU toxicity. Post-radiaton TURP increases the risk of incontinence five-fold.

Acute Disease↗
PubMed2004

Transposon mutagenesis of Trypanosoma brucei identifies glycosylation mutants resistant to concanavalin A.

We have engineered Trypanosoma brucei with a novel mariner transposition system that allows large populations of mutant cells to be generated and screened. As a proof of principle, we isolated and characterized two independent clones that were resistant to the cytotoxic action of concanavalin A. In both clones, the transposon had integrated into the locus encoding a homologue of human ALG12, which encodes a dolichyl-P-Man: Man(7)GlcNAc(2)-PP-dolichyl-alpha6-mannosyltransferase. Conventional knock-out of ALG12 in a wild-type background gave an identical phenotype to the mariner mutants, and biochemical analysis confirmed that they have the same defect in the N-linked oligosaccharide synthesis pathway. To our surprise, both mariner mutants were homozygous; the second allele appeared to have undergone gene conversion by the mariner-targeted allele. Subsequent experiments showed that the frequency of gene conversion at the ALG12 locus, in the absence of selection, was 0.25%. As we approach the completion of the trypanosome genome project, transposon mutagenesis provides an important addition to the repertoire of genetic tools for T. brucei.

Amino Acid Sequence↗
PubMed2004

Impact of neoadjuvant androgen ablation and other factors on late toxicity after external beam prostate radiotherapy.

PURPOSE: To evaluate the late toxicity profile of prostate cancer patients treated with external beam radiotherapy, to investigate the possible risk factors for late toxicity, and to determine whether neoadjuvant androgen ablation (NAA) is a factor. METHODS AND MATERIALS: The study population consisted of 1192 patients with > or =24 months' follow-up. Late GI and GU toxicities were scored with a modified Radiation Therapy Oncology Group/Subjective, Objective, Management, and Analytic scale. All patients were treated with external beam radiotherapy (52.5 Gy in 20 fractions to 72 Gy in 36 fractions), using either conventional or three-dimensional conformal techniques. Of the 1192 patients, 40% received NAA (median 5 months). Risk factors investigated on multivariate analysis were age, past medical history, use of pelvic fields, dose, fractionation, use and duration of neo- and adjuvant androgen ablation, and acute toxicity (Grade 2 or greater). RESULTS: The median follow-up for the group was 49 months (range 24-105). The incidence of late Grade 2-3 GI or GU toxicity was 30% at 5 years (GI 12% and GU 20%). The incidence of late Grade 3 GI or GU toxicity was 8% at 5 years (GI 2.7% and GU 5.5%). No Grade 4 toxicity occurred. The risk factors of significance in relation to the development of late Grade 3 GU toxicity were coexisting GU disease (p = 0.02), prior transurethral resection of the prostate or transurethral resection of bladder tumor (p <0.0001), and presence of acute GU toxicity (p = 0.012). For late Grade 3 GI toxicity, short-term (< or =2 months) NAA (p = 0.0002) and coexisting GI disease (p = 0.017) were risk factors. CONCLUSION: Short-term (< or =2 months) NAA, but not longer durations of NAA, increases the risk of developing Grade 3 GI late toxicity. The possible mechanism of this phenomenon is unclear.

Aged↗
PubMed2004

Opinion formation in evaluating sanity at the time of the offense: an examination of 5175 pre-trial evaluations.

Sanity evaluations are high-stake undertakings that explicitly examine the defendant's culpability for a crime and implicitly explore clinical information that might inform a plea agreement. Despite the gravity of such evaluations, relatively little research has investigated the process by which evaluators form their psycholegal opinions. In the current study, we explore this process by examining 5175 sanity evaluations conducted by a cohort of forensic evaluators in Virginia over a ten-year period. Our analyses focus on (i) the clinical, criminal, and demographic attributes of the defendant correlated with opinions indicative of insanity; (ii) the clinical content of the evaluations and the legal criteria referenced as the basis for the psycholegal opinion; (iii) the process and outcome differences in the sanity evaluations conducted by psychologists versus psychiatrists; and (iv) the consistency in these opinions over a ten year period. Analyses predicting an opinion of insanity indicate a positive relationship with psychotic, organic, and affective diagnoses and previous psychiatric treatment. Analyses also indicate a negative relationship with prior criminal history, drug charges, personality disorder diagnosis, and intoxication at the time of the offense. Modest racial disparities were observed with evaluators offering opinions that the defendant was insane more often for white than for minority defendants despite comparable psychiatric and criminal characteristics.

Adolescent↗
PubMed2003

A family of ductile intermetallic compounds.

Stoichiometric intermetallic compounds have always been touted for their attractive chemical, physical, electrical, magnetic and mechanical properties, but few practical uses have materialized because they are brittle at room temperature. Here we report on a large family of fully ordered, stoichiometric binary rare-earth intermetallic compounds with high ductility at room temperature. Although conventional wisdom calls for special conditions, such as non-stoichiometry, metastable disorder or doping to achieve some ductility in intermetallic compounds at room temperature, none of these is required in these unique B2 rare-earth compounds. Ab initio calculations of YAg, YCu and NiAl crystal defect energies support the observed deformation modes of these intermetallics.

Anisotropy↗
PubMed2003

Parasitic exploitation as an engine of diversity.

Parasitic exploitation occurs within and between a wide variety of taxa in a plethora of diverse contexts. Theoretical and empirical analyses indicate that parasitic exploitation can generate substantial genetic and phenotypic polymorphism within species. Under some circumstances, parasitic exploitation may also be an important factor causing reproductive isolation and promoting speciation. Here we review research relevant to the relationship between parasitic exploitation, within species-polymorphism, and speciation in some of the major arenas in which such exploitation has been studied. This includes research on the vertebrate major histocompatibility loci, plant-pathogen interactions, the evolution of sexual reproduction, intragenomic conflict, sexual conflict, kin mimicry and social parasitism, tropical forest diversity and the evolution of language. We conclude by discussing some of the issues raised by comparing the effect of parasitic exploitation on polymorphism and speciation in different contexts.

Animals↗
PubMed2003

Assessment of behavioral mechanisms maintaining encopresis: Virginia Encopresis-Constipation Apperception Test.

OBJECTIVE: To develop and test a scale for parent and child, evaluating theoretical and clinical parameters relevant to children with encopresis. Encopretic children were hypothesized to have more bowel-specific, but not more generic, psychological problems, as compared with nonsymptomatic control children. In addition, mothers were also believed to be more discerning than children. METHODS: The Virginia Encopresis-Constipation Apperception Test (VECAT) consists of 9 pairs of bowel-specific and 9 parallel generic drawings. Respondents selected the picture in each pair that best described them/their child. It was administered to encopretic children (N = 87), nonsymptomatic siblings (N = 27), and nonsymptomatic nonsiblings (N = 35). The mothers of all the participants also completed the VECAT. Encopretic children were retested 6 and 12 months posttreatment with Enhanced Toilet Training. RESULTS: The VECAT demonstrated good test-retest reliability and internal consistency. Encopretic children and their mothers reported more bowel-specific, but not more generic, problems. Bowel-specific scores improved significantly posttreatment only for those patients who demonstrated significant symptom improvement. Mothers were significantly more discerning than children. CONCLUSION: The VECAT is a reliable, valid, discriminating, and sensitive test. Bowel-specific problems appear to best differentiate children with and without encopresis.

Child↗