A comparative evaluation of two head and neck immobilization devices using electronic portal imaging

A study was performed to compare the positioning reproducibility and the cost efficiency for two head and neck immobilization devices: the Uvex (Uvex Safety, Smithfield, USA) plastic mask system and the Finesse Frame with Ultraplast System (PLANET Medical, Svendborg, Denmark). 20 patients treated with 3D conformal radiation therapy for head and neck cancers were randomly selected (10 for each of the two different immobilization systems) and electronic portal images acquired during their course of treatment were saved and used in this study. The anatomical landmark coordinates and their shifts in the anteroposterior (AP) and craniocaudal (CC) directions with respect to the digitized simulator films for lateral fields were analysed using an in-house developed portal image registration system. Statistically, no evidence was found to indicate that the systematic components of the displacement for the Uvex system and the Finesse Frame with Ultraplast System were different from each other or from zero. The random component of displacement was slightly smaller in the AP direction for the Uvex than the Ultraplast system (sigma = 1.9 mm and 2.9 mm, respectively, p = 0.007), but larger in the CC direction (sigma = 3.8 mm and 2.2 mm, respectively, p<10(-9)). Production time and required materials for a radiation therapy department were also quantified to assess costs for each system. The overall costs per patient were estimated at 141.50 dollars (CAD) and 82.10 dollars for the Uvex and Ultraplast systems, respectively. The Finesse Frame with Ultraplast System of immobilization for head and neck cancer treatment provides a field placement reproducibility that is equal to, or greater than, that of the Uvex plastic mask immobilization system and, while it requires more expensive materials, the workload and consequently overall cost is greatly reduced.

Virtual outreach: a randomised controlled trial and economic evaluation of joint teleconferenced medical consultations

OBJECTIVES

To test the hypotheses that virtual outreach would reduce offers of hospital follow-up appointments and reduce numbers of medical interventions and investigations, reduce numbers of contacts with the health care system, have a positive impact on patient satisfaction and enablement, and lead to improvements in patient health status. To perform an economic evaluation of virtual outreach.

DESIGN

A randomised controlled trial comparing joint teleconsultations between GPs, specialists and patients with standard outpatient referral. It was accompanied by an economic evaluation.

SETTING

The trial was centred on the Royal Free Hampstead NHS Trust, London, and the Royal Shrewsbury Hospital Trust in Shropshire. The project teams recruited and trained a total of 134 GPs from 29 practices and 20 consultant specialists.

PARTICIPANTS

In total, 3170 patients were referred, of whom 2094 consented to participate in the study and were eligible for inclusion. In all, 1051 patients were randomised to the virtual outreach group and 1043 to standard outpatient appointments. The patients were followed 6 months after their index consultation.

INTERVENTIONS

Patients randomised to virtual outreach underwent a joint teleconsultation, in which they attended the general practice surgery where they and their GP consulted with a hospital specialist via a videolink between the hospital and the practice.

MAIN OUTCOME MEASURES

Outcome measures included offers of follow-up outpatient appointments, numbers of tests, investigations, procedures, treatments and contacts with primary and secondary care, patient satisfaction (Ware Specific Visit Questionnaire), enablement (Patient Enablement Instrument) and quality of life (Short Form-12 and Child Health Questionnaire). An economic evaluation of the costs and consequences of the intervention was undertaken. Sensitivity analysis was used to test the robustness of the results.

RESULTS

Patients in the virtual outreach group were more likely to be offered a follow-up appointment. Significant differences in effects were observed between the two sites and across different specialities. Virtual outreach increased the offers of follow-up appointments more in Shrewsbury than in London, and more in ENT and orthopaedics than in the other specialities. Fewer tests and investigations were ordered in the virtual outreach group, by an average of 0.79 per patient. In the 6-month period following the index consultation, there were no significant differences overall in number of contacts with general practice, outpatient visits, accident and emergency contacts, inpatient stays, day surgery and inpatient procedures or prescriptions between the randomised groups. Tests of interaction indicated that virtual outreach decreased the number of tests and investigations, particularly in patients referred to gastroenterology, and increased the number of outpatient visits, particularly in those referred to orthopaedics. Patient satisfaction was greater after a virtual outreach consultation than after a standard outpatient consultation, with no heterogeneity between specialities or sites. However, patient enablement after the index consultation, and the physical and psychological scores of the Short Form-12 for adults and the scores on the Child Health Questionnaire for children under 16, did not differ between the randomised groups at 6 months' follow-up. NHS costs over 6 months were greater for the virtual outreach consultations than for conventional outpatients, pound 724 and pound 625 per patient, respectively. The index consultation accounted for this excess. Cost and time savings to patients were found. Estimated productivity losses were also less in the virtual outreach group.

CONCLUSIONS

Virtual outreach consultations result in significantly higher levels of patient satisfaction than standard outpatient appointments and lead to substantial reductions in numbers of tests and investigations, but they are variably associated with increased rates of offer of follow-up according to speciality and site. Changes in costs and technological advances may improve the relative position of virtual consultations in future. The extent to which virtual outreach is implemented will probably be dependent on factors such as patient demand, costs, and the attitudes of staff working in general practice and hospital settings. Further research could involve long-term follow-up of patients in the virtual outreach trial to determine downstream outcomes and costs; further study into the effectiveness and costs of virtual outreach used for follow-up appointments, rather than first-time referrals; and whether the costs of virtual outreach could be substantially reduced without adversely affecting the quality of the consultation if nurses or other members of the primary care team were to undertake the hosting of the joint teleconsultations in place of the GP. Qualitative work into the attitudes of the patients, GPs and hospital specialists would also be valuable.

Instability of the fragile X syndrome repeat in mice: the effect of age, diet and mutations in genes that affect DNA replication, recombination and repair proficiency

Repeat expansion diseases such as fragile X syndrome (FXS) result from increases in the size of a specific tandem repeat array. In addition to large expansions, small changes in repeat number and deletions are frequently seen in FXS pedigrees. No mouse model accurately recapitulates all aspects of this instability, particularly the occurrence of large expansions. This may be due to differences between mice and humans in CIS and/or TRANS-acting factors that affect repeat stability. The identification of such factors may help reveal the expansion mechanism and allow the development of suitable animal models for these disorders. We have examined the effect of age, dietary folate, and mutations in the Werner's syndrome helicase (WRN) and TRP53 genes on FXS repeat instability in mice. WRN facilitates replication of the FXS repeat and enhances Okazaki fragment processing, thereby reducing the incidence of processes that have been suggested to lead to expansion. p53 is a protein involved in DNA damage surveillance and repair. We find two types of repeat instability in these mice, small changes in repeat number that are seen at frequencies approaching 100%, and large deletions which occur at a frequency of about 10%. The frequency of these events was independent of WRN, p53, parental age, or folate levels. The large deletions occur at the same frequency in mice homozygous and heterozygous for the repeat suggesting that they are not the result of an interallelic recombination event. In addition, no evidence of large expansions was seen. Our data thus show that the absence of repeat expansions in mice is not due to a more efficient WRN protein or p53-mediated error correction mechanism, and suggest that these proteins, or the pathways in which they are active, may not be involved in expansion in humans either. Moreover, the fact that contractions occur in the absence of expansions suggests that these processes occur by different mechanisms.

Patients with small duct primary sclerosing cholangitis have a favourable long term prognosis

BACKGROUND

Patients with cholestatic liver function tests and histological features of primary sclerosing cholangitis (PSC) but a normal cholangiogram are considered to have small duct PSC. The natural history of this condition is unknown.

METHODS

Thirty three patients with small duct PSC were identified among patients admitted for diagnostic workup of cholestatic liver function tests in one centre in the UK (Oxford) and one centre in Norway (Oslo). A total of 260 patients with large duct PSC were compared, and prognosis in terms of death, cholangiocarcinoma, biochemical features, histological features, and symptoms analysed.

RESULTS

Mean age at diagnosis was 38 years and 39 years in small duct and large duct PSC, respectively. Mean follow up was 106 months in small duct and 105 months in large duct patients. Four patients originally considered to have small duct developed large duct PSC. Two of these underwent liver transplantation during follow up. Of the remainder who did not develop large duct PSC, two patients died during follow up: one of liver failure and the other of cardiac death unrelated to her liver disease. A total of 122 (47%) large duct patients either required liver transplantation (34 patients) or died (88 patients). Small duct patients had a significantly better survival compared with large duct patients. Among small duct patients, none developed cholangiocarcinoma compared with 28 of 260 (11%) large duct patients.

CONCLUSIONS

Patients with small duct PSC seem to have a good prognosis in terms of survival and development of cholangiocarcinoma. Small duct PSC progresses to large duct PSC in a small proportion of patients.

Effects of risperidone on aberrant behavior of persons with developmental disabilities: I. A double-blind crossover study using multiple measures

The efficacy of the atypical antipsychotic risperidone was evaluated in the treatment of aberrant behavior (e.g., aggression, self-injury) in 20 individuals with developmental disabilities. A double-blind, crossover design was used to compare risperidone with placebo in a 22-week trial with a 6-month follow-up phase. Based on a 50% reduction in mean Aberrant Behavior Checklist--Community total scores, 50% of the participants were identified as responders. Naturalistic observations of a subset of five individuals showed that for 4 out of 5 participants, risperidone was effective in reducing aberrant behavior. Side effects included weight gain (84% of participants) and sedation (40% of participants). The advantages of conducting a comprehensive analysis of the effects of medication on aberrant behavior are discussed.

Clozapine enhances neurocognition and clinical symptomatology more than standard neuroleptics

Neurocognition and clinical symptomatology were evaluated in 27 patients with schizophrenia during a double-blind, placebo-controlled, cross-over study involving clozapine, an atypical antipsychotic agent, and haloperidol, a conventional neuroleptic. Patients were assessed 5 to 6 weeks after initiation of each phase. Clinical symptomatology, based on Brief Psychiatric Rating Scale and Scale for the Assessment of Negative Symptoms ratings, markedly improved after treatment with both haloperidol and clozapine. The beneficial effects of clozapine were statistically significantly greater than the effects from the haloperidol treatment. Regarding neurocognition, both agents proved efficacious in improving performance on nearly all measures compared with placebo. In addition, as compared with haloperidol, clozapine significantly improved performance on Trails B, Verbal Fluency, and measures of delayed verbal memory, and it tended to increase performance on most measures. Additional analyses indicated that the improvement on neurocognitive measures was not because of symptom amelioration; rather, neurocognitive deficits seem to be an intrinsic enduring feature of schizophrenia. The superiority of clozapine over haloperidol may be related to clozapine's unique psychopharmacologic profile.

Brain metabolic and clinical effects of rivastigmine in Alzheimer's disease

In-vivo metabolic measures with positron emission tomography using (18)F-fluorodeoxyglucose (FDG-PET) have demonstrated hypometabolism in temporal, frontal, and hippocampal areas during the early stages of Alzheimer's disease (AD). Progression of the dementia in AD involves compromised cholinergic functioning. Cholinesterase inhibitors have demonstrated efficacy in improving cognition and behaviour in AD. In this study, we demonstrate the usefulness of FDG-PET in measuring the progression of untreated AD and its modification by treatment with rivastigmine (Exelon, Novartis Pharmaceuticals, East Hanover, New Jersey, USA), a centrally selective cholinesterase inhibitor of the carbamate type. Patients with mild to moderate probable AD (Mini-Mental Status Exam scores of 10-26, inclusive) were enrolled in a double-blind, placebo controlled comparison of three fixed daily doses of rivastigmine (3, 6, or 9 mg/d) or placebo for 26 wk. FDG-PET scans were obtained on 27 patients at baseline and following 26 wk of treatment using the Snodgrass Picture Naming activation task. A total of 71.4% of the patients treated with placebo deteriorated clinically compared to only 25.0% of the patients treated with rivastigmine (chi2 = 4.8; p & 0.03). Rivastigmine-responders (i.e. those who clinically improved or remained clinically stable as measured by the Clinicianaposs Interview-Based Impression of Change-plus) showed a marked increase in brain metabolism (p <0.01) involving, but not limited to, structures comprising the memory-related cortices and the prefrontal system. These metabolic changes were not observed in the placebo-treated patients or the rivastigmine non-responders. Of note is that responders increased hippocampal metabolism by 32.5% (p < 0.03) compared to a non-significant decrease in the non-responders (6.4%) and placebo-treated patients (4.1%). These results are consistent with the literature suggesting that FDG-PET can sensitively measure the progression of AD and its improvement with cholinesterase inhibitors. Rivastigmine prevented the expected deterioration in clinical status and dramatically increased brain metabolic activity in a majority of patients.

The solution structure of PapGII from uropathogenic Escherichia coli and its recognition of glycolipid receptors

Uropathogenic Escherichia coli (UPEC) is the primary cause of symptomatic urinary tract infection. The P-pili, a bacterial surface organelle, mediates the bacterial host--cell adhesion. The PapG adhesin has generated much interest in recent years, not only because of its clinical value, i.e. in the prevention of microbial adherence, but also because of its ability to promote virulence. Using multidimensional nuclear magnetic resonance (NMR) and deuteration we have determined the solution structure of the adhesin domain from PapGII (PapGII-198). The novel structure of PapGII-198 is composed of a large elongated jellyroll motif. Despite an automated search of the structural database failing to reveal any similar proteins, PapGII adhesin shares some structural similarities with FimH. Furthermore, interpretation of NMR-titration data has enabled us to identify the putative binding site for the globoseries of oligosaccharides. This work provides insight into UPEC pathogenesis as well as aiding the development of preventative therapies and the guidance of future mutagenesis programmes.

Cellulose crystallites

This article discusses advances in understanding the structural and physicochemical characteristics of suspensions of cellulose crystallites prepared by acid hydrolysis of natural cellulose fibres. Consideration of recent developments in visualization of crystallite ultrastructure may provide clues to suspension behavior. In addition, novel applications in a diverse range of fields are presented, from iridescent pigments to biomolecular NMR studies.

The marketing function in managed care systems

As managed care spreads through the health care service industry, marketing professionals are faced with the challenge of marketing highly integrated systems. This paper explores three questions related to this development: (1) what is unique about managed care marketing, (2) how has managed care impacted health care marketing, and (3) what new strategies and trends will shape these developing markets?

Learning and forgetting in schizophrenia

Recent studies of patients with schizophrenia have consistently demonstrated marked deficits on measures of initial learning. However, contradictory results have been reported concerning retention and forgetting. The present study examined the level of initial and delayed recall of stories and visual figures in a group of 76 patients with schizophrenia and 51 normal controls. Schizophrenia patients demonstrated marked impairments in initial and delayed recall as well as significantly worse percentage retention scores. However, schizophrenia patients and healthy controls individually matched on level of initial recall had nearly identical delayed recall performance. The results suggest a primary deficit in the initial acquisition of information rather than an accelerated rate of forgetting in schizophrenia.

Structure of the cell-adhesion fragment of intimin from enteropathogenic Escherichia coli

Enteropathogenic Escherichia coli (EPEC) induce gross cytoskeletal rearrangement within epithelial cells, immediately beneath the attached bacterium. The C-terminal 280 amino acid residues of intimin (Int280; 30.1 kDa), a bacterial cell-adhesion molecule, mediate the intimate bacterial host-cell interaction. Recently, interest in this process has been stimulated by the discovery that the bacterial intimin receptor protein (Tir) is translocated into the host cell membrane, phosphorylated, and after binding intimin triggers the intimate attachment. Using multidimensional nuclear magnetic resonance (NMR) and combining perdeuteration with site-specific protonation of methyl groups, we have determined the global fold of Int280. This represents one of the largest, non-oligomeric protein structures to be determined by NMR that has not been previously resolved by X-ray crystallography. Int280 comprises three domains; two immunoglobulin-like domains and a C-type lectin-like module, which define a new family of bacterial adhesion molecules. These findings also imply that carbohydrate recognition may be important in intimin-mediated cell adhesion.

Is P50 suppression a measure of sensory gating in schizophrenia?

BACKGROUND

Abnormal P50 response has been hypothesized to reflect the sensory gating deficit in schizophrenia. Despite the extensive literature concerning the sensory filtering or gating deficit in schizophrenia, no evidence has been provided to test the relationship of the P50 phenomenon with patients' experiences of perceptual anomalies.

METHODS

Sixteen drug-free DSM-IV diagnosed schizophrenic patients who reported moderate to severe perceptual anomalies in the auditory or visual modality were examined as compared to 16 schizophrenic patients who did not report perceptual anomalies, and 16 normal subjects. Both control groups were age- and gender-matched with the study group.

RESULTS

Patients reporting perceptual anomalies exhibited P50 patterns that did not differ from normal subjects. In contrast, patients who did not report perceptual anomalies showed the abnormal P50 ratios previously found to be associated with schizophrenia.

CONCLUSIONS

These paradoxical findings do not support the hypothetical relationship between the P50 and behavioral measures of sensory gating, suggesting that additional studies are needed to further explore the clinical correlates of the P50.

Structure and functional relationships in human pur H

1. The human pur H (ATIC) gene encoding a bifunctional protein, hPurH, which carries the penultimate and final enzymatic activities of the purine nucleotide synthesis pathway, AICARFT & IMPCH, has been cloned and sequenced. The gene product, hPurH has been overexpressed in E. coli, purified to homogeneity and crystallized. 2. The human pur H gene lies on chromosome 2, between band q34 and q35. There is at least one intron of 278 bp near the 5' end. 3. Truncation mutant studies demonstrate two non-overlapping functional domains in the protein arranged as indicated in Figure 5. The existence of a linker or interaction region between the catalytic domains remains to be established. 4. Cleland-type kinetic inhibition experiments indicate that the AICARFT reaction is of the ordered, sequential type with the reduced folate cofactor binding first. 5. The reaction has a broad pH optimum in the alkaline range, with a maximum at about pH 8.2. 6. Preliminary transient phase kinetic studies show the presence of a "burst" indicating that a late step in the reaction sequence is rate limiting. 7. A PurH crystal structure is that of a dimer, with a putative single binding site for the reduced folate cofactor formed using elements from each of the monomer subunits. Probable binding sites for AICAR and FAICAR can be identified on each monomer. 8. Equilibrium sedimentation studies show hPurH apoprotein to be a monomer:dimer equilibrium mixture with a kD of 0.55 uM. 9. The crystal structure has permitted identification of a number of candidate amino acid residues likely to be involved in catalysis and/or substrate binding. Among these, we have thus far completed studies on two, Lysine 265 and Histidine 266. These appear to be critically involved in the AICARFT reaction, although whether their role(s) are in catalysis or binding remains to be determined.

Uncoupling cognitive workload and prefrontal cortical physiology: a PET rCBF study

Working memory is a fundamental cognitive building block involved in the short-term maintenance and transformation of information. In neuropsychological studies, working memory has been shown to be of limited capacity; however, the neurophysiological concomitants of this capacity limitation have not been explored. In this study we used the [15O] water PET rCBF technique and statistical parametric mapping to examine normal subjects while they performed two cognitive tasks, both individually and simultaneously. One task was the Wisconsin Card Sorting Test, a complex reasoning task involving working memory, and the other was a rapidly paced auditory verbal shadowing task. When both tasks were performed simultaneously, there were significant decrements in performance compared with the individual task performance scores, indicating that cognitive workload had been increased. Analysis of the rCBF maps showed that when the two tasks were performed together, in contrast to when they were performed separately, there was less prefrontal activation. These results suggest that increases in cognitive workload do not necessarily recruit and then sustain cortical neurophysiological resources to a maximum, but rather may actually be accompanied by a diminution in cortical activity.

Patterns and associates of hyperphagia in patients with dementia

This study examined patterns and associates of excessive eating (hyperphagia) in a community-based registry of patients with dementia. From patients enrolled in the Mayo Clinic Alzheimer's Disease Patient Registry (n = 439), 39 were identified with excessive eating reported on the Behavior Symptom Checklist at some time during their illness. They were matched for age, gender, duration of disease, and Global Deterioration Scale (GDS) score to "normal eaters." Annualized weight change was determined based on weight from the 6 months before the evaluation to weight 6 months after the evaluation. Annualized weight change scores were not significantly different between excessive eaters and normal eaters nor between wanderers and nonwanderers. In cross-sectional analysis, univariate modeling suggested age at onset, GDS, and Mini-Mental State Examination score to be significant predictors of excessive eating. Using multivariate logistic model with backward elimination, only age of onset and GDS were retained as associates of excess eating. Rater type also emerged as a significant predictor for excessive eating with family raters reporting this behavior in 16% of patients compared to 5% for other raters. In chi-square analyses excessive eating was associated with greater frequency of wandering, unpredictable behavior, inappropriate dressing, inappropriate bodily concerns, and threatening self-harm. Associates of excess eating were subsequently examined separately in wandering and nonwandering excessive eaters. Logistic modeling suggested that among nonwanderers, patients who were younger but more severely demented were likely to have reported excessive eating. These results suggest hyperphagia to be present in approximately 10% of a community-based cohort of patients with dementia and associated with increasing functional decline. Excessive eating does not appear to arise from memory dysfunction, but for wanderers may result from needing increased caloric intake because of increased activity levels. Thus, for wandering excessive eaters, it may be appropriate to endure the eating to ensure appropriate caloric intake. Nonwandering excessive eaters were younger, had greater dementia severity, and had more unpredictable behavior. They may have dementia with prominent frontal lobe involvement and may respond to any food stimulus respective of hunger. Restricting food exposure may be an effective management intervention for them.

Latex foam and staple fixation of skin grafts

Skin grafts are time consuming to secure effectively. We report our experience with a simple, versatile and rapid technique utilising staples and a latex foam dressing.