Long-term cost-effectiveness of Dexcom G6 real-time continuous glucose monitoring system in people with type 1 diabetes in Australia

INTRODUCTION

Real-time continuous glucose monitoring (rt-CGM) allows patients with diabetes to adjust insulin dosing, potentially improving glucose control. This study aimed to compare the long-term cost-effectiveness of the Dexcom G6 rt-CGM device versus self-monitoring of blood glucose (SMBG) and flash glucose monitoring (FGM) in Australia in people with type 1 diabetes (T1D).

METHODS

Long-term costs and clinical outcomes were estimated using the CORE Diabetes Model. Clinical input data for the analysis of rt-CGM versus SMBG and FGM were sourced from the DIAMOND study and a network meta-analysis, respectively. Rt-CGM and FGM were associated with quality of life (QoL) benefits due to reduced fear of hypoglycaemia (FoH) and fingerstick testing. Analyses were performed over a lifetime time horizon from an Australian healthcare payer perspective, including direct costs from published data. Future costs and clinical outcomes were discounted at 5% per annum.

RESULTS

Rt-CGM was associated with an increased quality-adjusted life expectancy of 1.199 quality-adjusted life years (QALYs), increased mean total lifetime costs of AUD 21,596 and an incremental cost-effectiveness ratio (ICER) of AUD 18,020 per QALY gained compared with SMBG. Compared with FGM, rt-CGM was associated with an increased quality-adjusted life expectancy of 0.569 QALYs, increased mean total lifetime costs of AUD 11,064 and an ICER of AUD 19,455 per QALY gained. Key drivers of outcomes included HbA_1c benefits and QoL benefits associated with reduced FoH and fingerstick testing.

CONCLUSIONS

Due to improved clinical outcomes and QoL gains rt-CGM is highly cost-effective compared with SMBG and FGM in people with T1D in Australia.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Romidepsin and lenalidomide-based regimens have efficacy in relapsed/refractory lymphoma: Combined analysis of two phase I studies with expansion cohorts

Romidepsin (histone deacetylase inhibitor), lenalidomide (immunomodulatory agent), and carfilzomib (proteasome inhibitor), have efficacy and lack cumulative toxicity in relapsed/refractory lymphoma. We performed two investigator initiated sequential phase I studies to evaluate the maximum tolerated dose (MTD) of romidepsin and lenalidomide (regimen A) and romidepsin, lenalidomide, and carfilzomib (regimen B) in relapsed/refractory lymphoma. Cohorts in T-cell lymphoma (TCL), B-cell lymphoma (BCL) were enrolled at the MTD. Forty-nine patients were treated in study A (27 TCL, 17 BCL, 5 Hodgkin lymphoma (HL)) and 27 (16 TCL, 11 BCL) in study B. The MTD of regimen A was romidepsin 14 mg/m² IV on days 1, 8, and 15 and lenalidomide 25 mg oral on days 1-21 of a 28-day cycle. The MTD of regimen B was romidepsin 8 mg/m² on days 1 and 8, lenalidomide 10 mg oral on days 1-14 and carfilzomib 36 mg/m² IV on days 1 and 8 of a 21-day cycle. In study A, 94% had AEs ≥Grade 3, most commonly neutropenia (49%), thrombocytopenia (53%), and electrolyte abnormalities (49%). In study B 59% had AEs ≥Grade 3, including thrombocytopenia (30%) and neutropenia (26%). In study A the ORR was 49% (50% TCL, 47% BCL, 50% HL). In study B the ORR was 48% (50% TCL, 50% BCL). For study A and B the median progression free survival (PFS) was 5.7 months and 3.4 months respectively with 11 patients proceeding to allogeneic transplant. The combinations of romidepsin and lenalidomide and of romidepsin, lenalidomide and carfilzomib showed activity in relapsed/refractory lymphoma with an acceptable safety profile.

'Maybe I will give some help…. maybe not to help the eyes but different help': an analysis of care and support of children with visual impairment in community settings in Malawi

BACKGROUND

Visual impairment in children is common in low and middle-income settings. Whilst visual impairment (VI) can impact on the development of children, many reach full potential with appropriate early intervention programmes. Although there is increased emphasis on early child development globally, it is not yet clear how to provide specific programmes for children with VI in low and middle-income settings. This study aims to identify facilitators and barriers to the provision of a developmental stimulation programme for children with VI in rural and urban Malawi.

METHODS

We undertook 6 focus groups, 10 home observations and 20 in-depth interviews with carers of children with VI under 6 years in urban and rural Southern Malawi. We utilised topic guides relating to care, play, communication and feeding. Qualitative data were subject to thematic analysis that included placing themes within Bronfenbrenner's ecological framework. We established authenticity of themes through feedback from participants.

RESULTS

We identified themes within Bronfenbrenner's framework at five levels: (1) blindness acting as a barrier to stimulation and communication, health and complex needs all affecting the individual child; (2) understanding of VI, ability to be responsive at the microsystem level of the carer; (3) support from other carers at microsystem level within a mesosystem; (4) support from other professionals (knowledge of, identification and management of children with VI, responsibilities and gender roles, environmental safety and prejudice, stigma and child protection all at the level of the exosystem.

DISCUSSION

This study has revealed the requirements needed in order to produce meaningful and appropriate programmes to support nutrition, care and early stimulation for children with VI in this and similar African settings. This includes supporting carers to understand their child's developmental needs, how to better communicate with, feed and stimulate their child; offering advice sensitive to carers' responsibilities and professional training to better support carers and challenge community stigma.

Clients with intellectual disabilities on psychiatric units: care coordination for positive outcomes

The transition from residential facilities to and from the psychiatric hospital setting is difficult for individuals with intellectual disabilities (ID). In the U.S.A., specialized psychiatric units for individuals with ID are uncommon and this population is usually served in generalized services. Nevertheless, providers of mental health services in the U.S.A. receive little training in their specific needs. Best practices call for coordination of plans between psychiatric units and community agencies, multidisciplinary care plans, staff education and comprehensive discharge planning in order to improve outcomes of psychiatric hospitalization. An inner city psychiatric unit in a major academic medical centre and a community agency providing residential care for individuals with ID cooperated to provide a plan of care for a client with ID both for hospitalization and for discharge leading to improved outcomes.

Socioeconomic impact on device-associated infections in limited-resource neonatal intensive care units: findings of the INICC

PURPOSE

To evaluate the impact of country socioeconomic status and hospital type on device-associated healthcare-associated infections (DA-HAIs) in neonatal intensive care units (NICUs).

METHODS

Data were collected on DA-HAIs from September 2003 to February 2010 on 13,251 patients in 30 NICUs in 15 countries. DA-HAIs were defined using criteria formulated by the Centers for Disease Control and Prevention. Country socioeconomic status was defined using World Bank criteria.

RESULTS

Central-line-associated bloodstream infection (CLA-BSI) rates in NICU patients were significantly lower in private than academic hospitals (10.8 vs. 14.3 CLA-BSI per 1,000 catheter-days; p < 0.03), but not different in public and academic hospitals (14.6 vs. 14.3 CLA-BSI per 1,000 catheter-days; p = 0.86). NICU patient CLA-BSI rates were significantly higher in low-income countries than in lower-middle-income countries or upper-middle-income countries [37.0 vs. 11.9 (p < 0.02) vs. 17.6 (p < 0.05) CLA-BSIs per 1,000 catheter-days, respectively]. Ventilator-associated-pneumonia (VAP) rates in NICU patients were significantly higher in academic hospitals than in private or public hospitals [13.2 vs. 2.4 (p < 0.001) vs. 4.9 (p < 0.001) VAPs per 1,000 ventilator days, respectively]. Lower-middle-income countries had significantly higher VAP rates than low-income countries (11.8 vs. 3.8 per 1,000 ventilator-days; p < 0.001), but VAP rates were not different in low-income countries and upper-middle-income countries (3.8 vs. 6.7 per 1,000 ventilator-days; p = 0.57). When examined by hospital type, overall crude mortality for NICU patients without DA-HAIs was significantly higher in academic and public hospitals than in private hospitals (5.8 vs. 12.5%; p < 0.001). In contrast, NICU patient mortality among those with DA-HAIs was not different regardless of hospital type or country socioeconomic level.

CONCLUSIONS

Hospital type and country socioeconomic level influence DA-HAI rates and overall mortality in developing countries.

Comparison of the MMSE and RUDAS cognitive screening tools in an elderly inpatient population in everyday clinical use

We compared test score and performance times of Folstein's Mini Mental State Examination (MMSE) and the Rowland Universal Dementia Assessment Scale (RUDAS). Forty-six patients were recruited. The mean score was 20.6 for the MMSE and 20.5 for the RUDAS. Linear regression analysis revealed an r value of 0.83 (P < 0.05). The mean performance time was 9.4 min for both the MMSE and the RUDAS. Patient satisfaction was similar for both tests. Surveyed clinicians preferred the MMSE because of greater familiarity. We concluded that the RUDAS correlates well with the MMSE and is no more time-consuming to perform. It has good clinical utility as a cognitive screening tool.

Variations in oxytocin regimes in Scottish labour wards in 1998

Oxytocin (Syntocinon, Sandoz Pharmaceuticals) is a commonly used drug in the modern management of labour. A recently published British survey found that 38% of low risk primigravid labours were augmented, most commonly by intravenous syntocinon. Unfortunately the misuse of syntocinon can lead to potentially serious problems for the fetus and mother. Despite the frequency of usage there appears to be no consensus as to the optimal dose and mode of administration. This paper explores the extent of this variation among Scottish obstetric units, the reasons for any variation in its use and makes some suggestions as to the way forward based on the current literature.

Diabetes care in hospital--the impact of a dedicated inpatient care team

AIMS

At any given time, people with diabetes occupy approximately 5-10% of acute hospital beds. In addition, diabetes is associated with a greater length of stay (LOS). This is partially because of increased complexity of the cases but also because of unfamiliarity of dealing with the condition by other specialist teams.

METHODS

In 2002, with increasing pressure on acute hospital beds, a team was established to improve the care of inpatients with diabetes admitted to Derriford Hospital. The team consisted of five diabetes specialist nurses dedicated to inpatient care, supported by a consultant and specialist registrar diabetologist. A link nurse responsible for diabetes was appointed on every ward and each individual with a diagnosis of diabetes was identified on admission. We have compared LOS of all patients with diabetes admitted between January 2002 and December 2006.

RESULTS

LOS fell from a mean +/- se of 8.3 +/- 0.18 days in 2002 to 7.7 +/- 0.10 days in 2006 (P = 0.002). Significant falls were seen for emergency admissions (9.7 +/- 0.23 vs. 9.2 +/- 0.20, P < 0.001) but not elective admissions. The data show significant reductions in LOS for medical admissions (9.2 +/- 0.24 vs. 8.4 +/- 0.20, P < 0.001) but not surgical admissions. Over the same period, LOS for the total hospital population fell by 0.3 days (P < 0.001).

CONCLUSION

In conclusion, a team specifically employed to focus on inpatient diabetes care has a significant impact on LOS of this patient group.

Bundling and Diameter Selectivity in HiPco SWNTs Poly(p-phenylene vinylene-co-2,5-dioctyloxy-m-phenylene vinylene) Composites

Temperature-dependent (TD) Raman measurements at laser excitation 514.5 nm were performed at different concentrations. The spectral profile of the radial breathing modes were investigated up to a polymer concentration of 1 g/L and were found to be dominated by approximately 1.2-1.4 nm diameter tubes at room temperature. Upon heating above the glass transition of the polymer (60 degrees C) the smaller tubes around approximately 0.9 nm increased significantly in relative intensity. This suggests that below the glass transition of the polymer (60 degrees C) RBMs within the composite are damped and spectral changes cannot be interpreted as diameter selective solubilization. The observed RBM damping at room temperature only occurred up to a concentration of approximately 1.2 x 10(-4) g/L and below this no damping was observed. Photoluminescence intensity (PL) measurements were taken for a range of PmPV concentrations, in which HiPco single walled carbon nanotubes (SWNTs) at 100%, 10%, 1%, 0.1%, 0.01%, and 0% mass fractions were added. Fitting of the concentration dependence to a dynamic absorption/desorption model indicates that the polymer interacts with nanotube bundles until a critical concentration of approximately 1.2 x 10(-4) g/L is reached, below which the nanotubes are isolated. The polymer and or solvent has a significant effect on the debundling and aggregation within these systems. Aggregation and/or interaction with the polymer at higher concentrations can effect the RBM profile in the composite at ambient temperatures, providing an incomplete representation of the selection of diameters present within composites at a particular wavelength.

Measles case imported from Europe to Victoria, Australia, March 2006

A 33 year old man returned home to the Australian state of Victoria on 11 March 2006, after a three week holiday travelling through Europe

CO2 molecule as a quantum realization of the 1:1:2 resonant swing-spring with monodromy

We consider the wide class of systems modeled by an integrable approximation to the 3 degrees of freedom elastic pendulum with 1:1:2 resonance, or the swing-spring. This approximation has monodromy which prohibits the existence of global action-angle variables and complicates the dynamics. We study the quantum swing-spring formed by bending and symmetric stretching vibrations of the CO2 molecule. We uncover quantum monodromy of CO2 as a nontrivial codimension 2 defect of the three dimensional energy-momentum lattice of its quantum states.

Cavitary Legionella pneumonia in a liver transplant recipient

This report describes the clinical course of a liver transplant recipient in whom cavitary pneumonia developed due to Legionella pneumophila. We review the experience with cavitary pulmonary processes caused by Legionella species in liver allograft recipients and describe the diagnostic microbiology of this organism. The clinical course of this patient demonstrates the importance of considering legionellosis in the differential diagnosis of lung abscesses after liver transplantation and the diagnostic difficulties encountered with this bacterium.

Social problems in oncology

A study was undertaken to describe, evaluate and categorise the social problems experienced by cancer patients. Ninety-six adult cancer patients at all stages of disease participated in either a telephone focus group discussion, a face to face focus group or an individual interview which were tape recorded and transcribed. Six experts analysed the transcripts. A total of 32 social problems were identified categorized under eight headings plus four single items. The categories were: problems with (1) managing in the home, (2) health and welfare services, (3) finances, (4) employment, (5) legal matters, (6) relationships, (7) sexuality and body image and (8) recreation. Problems with relationships and communication were the most frequently reported with financial, employment, body image and domestic problems also being widely endorsed. Female groups, younger patient groups and groups where the aim of treatment was palliative reported more social problems than other groups. Social problems are common and important to cancer patients. The social problems identified in this study will contribute to an item pool generated for developing a Social Problems Inventory that may be included in patient centred assessment as part of routine oncology practice.

Detection of sequence variations in the adenomatous polyposis coli (APC) gene using denaturing high-performance liquid chromatography

We have evaluated the usefulness of denaturing high performance liquid chromatography (dHPLC) for scanning the adenomatous polyposis coli (APC) gene for point mutations, small deletions, and insertions. Our assay consists of 28 sets of primers to amplify the 15 exons of the APC gene. All PCR reactions were amplified simultaneously using the same reaction conditions in a 96-well format and then analyzed by dHPLC, using empirically determined optimum temperatures for partial fragment denaturation. Previously studied DNA specimens from 47 familial adenomatous polyposis (FAP) patients were analyzed by dHPLC and all mutations were correctly identified and confirmed by sequence analysis. This approach identified a single-base substitution in exon 6 and a 2-bp insertion in exon 15 that initially had not been detected by single-strand conformational polymorphism (SSCP) analysis. A novel mutation in exon 15 of the APC gene, 2065delG (codon 689) that had previously been undetected by the protein truncation test (PTT) was also identified by dHPLC. We present our validation studies of dHPLC technology for APC gene analysis in terms of sensitivity and specificity and compare it to current standard scanning technologies including PTT, SSCP, and conformational sensitive gel electrophoresis (CSGE).

Infection control dogma: top 10 suspects

As infection control evolved into an art and science through the years, many infection control practices have become infection control dogmas (principles, beliefs, ideas, or opinions). In this "Reality Check" session of the 4th Decennial International Conference on Nosocomial and Healthcare-Associated Infections, we assessed participants' perceptions of prevalent infection control dogmas. The majority of participants agreed with all dogmas having evidence of efficacy, except for the dogma on the frequency of changing mechanical-ventilator tubing. In contrast, the majority of participants disagreed with dogmas not having evidence of efficacy, except for the dogma on perineal care, umbilical cord care, and reminder signs for isolation precaution. As for controversial dogmas, many of the responses were almost evenly distributed between "agree" and "disagree." Infection control professionals were knowledgeable about evidence-based infection control practices. However, many of the respondents still believe in some of the non-evidence-based dogmas.

Improved overall survival among responders to preoperative chemoradiation for locally advanced rectal cancer

The aim of this study was to determine if the response to preoperative radiation and chemotherapy with continuous infusion 5-fluorouracil (5-FU) was predictive for survival among patients with locally advanced rectal cancer. Preoperative chemoradiation (CTX/XRT) that delivered 45 Gy in 25 fractions over 5 weeks with continuous infusion 5-FU (300 mg/m2/day) was given to 117 patients. The pretreatment stage distribution, as determined by endorectal ultrasound (u), included uT2N0 in 2%, uT3N0 in 47%, uT3N1 in 49%, and uT4N0 in 2% of cases; endorectal ultrasound was not performed in 13% of cases (15 patients). Approximately 6 weeks after completion of CTX/XRT, surgery was performed. Adjuvant chemotherapy, consisting of 400 to 425 mg/m2 of 5-FU plus 20 mg/m2 leucovorin for 5 days, was administered every 28 days for 4 to 6 cycles after surgical resection. Among the 74 patients treated with adjuvant chemotherapy, the preoperative stage of disease was 31 with T3N0 and 43 T3N1. Median follow-up was 46 months (range 2 to 89 months). The pathologic tumor stages were Tis-2N0 in 26%, T2N1 in 5%, T3N0 in 21%, T3N1 in 15%, T4N0 in 5%, and T4N1 in 1%; a complete response (CR) to preoperative CTX/XRT was pathologically confirmed in 32 (27%) of patients. Tumor down-staging occurred in 72 (62%) cases. A sphincter-saving procedure (SP) was possible in 59% of patients. The median DFS and overall survival rates for responders were 46 months and 47 months, respectively; for non-responders these outcome measures were 38 months and 41 months, respectively. Log-rank analysis showed that the distant metastatic-free survival rates improved with any response to CTX/XRT (p < 0.00001), CR to CTX/XRT (p < 0.009) and SP (p < 0.012). Likewise, these parameters also significantly influenced DFS rates (CTX/XRT p < 0.00001; CR p < 0.006; and SP p < 0.008). Control of pelvic disease was influenced by clinical size (p < 0.002) and SP (p < 0.016) on univariate analysis. On multivariate analysis only clinical size (p < 0.002) continued to be a significant factor for local control. Factors on multivariate analysis that resulted in significant improvements in cancer-specific survival included any response to preoperative CTX/XRT (p < 0.017) and administration of adjuvant chemotherapy (p < 0.034). Any response to preoperative CTX/XRT improved distant metastatic-free and disease-free survival rates. Multivariate analysis confirmed that a response to preoperative CTX/XRT predicted for improvements in overall survival among patients with locally advanced rectal cancer. Patients who fail to respond to preoperative 5-FU based chemotherapy given concomitantly with radiation have higher rates of distant metastases with adjuvant 5-FU therapy.

Research Priorities Project, year 2000: establishing a direction for infection control and hospital epidemiology

BACKGROUND

The field called "infection control" has expanded beyond hospitals to include many health care locations, some aspects of personnel health, elements of noninfectious complications, and occasionally the epidemiology of other problems that occur in care facilities. A research agenda that addresses these newer segments and provides a framework for answering fundamental questions is essential for the field and for the work of The Research Foundation for Prevention of Complications Associated with Health Care (formerly APIC Research Foundation).

METHODS

We used a multiple-round iterative consensus process (Delphi technique) with 50 experts and a validation round among participants at the 4th Decennial Conference.

RESULTS

The expert panel reduced 102 separate items to 21 high-ranked research priorities. The highest-ranked subject areas involved research to improve compliance with excellent practices, to study antibiotic usage and resistance, to measure the financial impact of complications and value of interventions, to perform surveillance of infectious and noninfectious complications across the spectrum of care delivery, and to study effectiveness of interventions to prevent complications at specific sites. There were differences in education and discipline between the expert panel and the 4th Decennial participants and with respect to ranking some of the individual priorities. Among respondents from outside the United States and Canada, occupational health issues were ranked more highly.

CONCLUSIONS

The research priorities provide a blueprint for future progress and will require a collaborative, multicenter, multinational approach.

Effective pelvic symptom control using initial chemoradiation without colostomy in metastatic rectal cancer

PURPOSE

To assess pelvic chemoradiotherapy (CXRT) without colostomy as a component of the multidisciplinary management of patients presenting with metastatic rectal cancer.

METHODS AND MATERIALS

Eighty patients with synchronous distant metastases from rectal cancer were treated with initial CXRT. Hypofractionated radiotherapy was administered usually with concurrent 5-FU (92%, 300 mg/m(2)/day, M-F). Three-field belly-board technique was used in 89%. Group 1 had CXRT alone (n = 55). Group 2 (n = 25) patients were selected for primary disease resection, and sometimes HAI chemotherapy (n = 10) or hepatic resection (n = 5). Subsequently, 78% received systemic chemotherapy.

RESULTS

Symptoms from primary tumor resolved in 94%. Endoscopic complete clinical response rate was 36%. Two-year survival (11% vs. 46%, p < 0.0001) and symptomatic pelvic control (PC, 81% vs. 91%, p = 0.111) were higher in Group 2, but colostomy-free rate (CFR) was lower (79% vs. 51% p = 0.02). CFR was 87% in Group 1 patients managed initially without fecal diversion (n = 50). Examining all patients using multivariate analysis, pelvic pain at presentation (p < 0.00001), BED (biologic equivalent dose at 2 Gy/fraction) < 35 Gy (p = 0.077), and poor differentiation (0.079) predicted worse PC. Poor differentiation (p = 0.017) and selection for CXRT alone (p < 0.0001) predicted worse survival. There were 4 RTOG of Grade 3 or greater acute complications, 5 severe perioperative complications, and no significant late treatment-related complications.

CONCLUSION

Durable PC can be safely achieved without colostomy in most patients presenting with primary rectal cancer and synchronous systemic metastases using hypofractionated pelvic chemoradiation. A BED greater than 35 Gy is recommended. Selected patients appear to benefit from resection of primary disease. Higher doses should be investigated in patients with pelvic pain.

X-ray diffraction line broadening from thermally deposited gold films

Diffraction profiles were analysed from thermally deposited 111-oriented gold films, ranging in thickness from 300 to 1900 Å. The data were collected using the high-resolution powder diffractometer on beamline BM16 at the European Synchrotron Research Facility (ESRF) set at a wavelength of 0.3507 Å. The profiles were measured under conventional symmetric θ–2θ reflection conditions and by asymmetric transmission diffraction to ensure that only crystallites oriented normal to the substrate contribute to the diffraction. An analysis of the instrument profile shape of the diffractometer was undertaken using the SRM 660 LaB6line profile standard. A parallel study of the films using atomic force microscopy and transmission electron microscopy was also undertaken to provide information on the dimensions of the crystallite columns in the films and the presence of dislocations. All the films displayed diffraction broadening arising from both crystallite-size effects and dislocation-induced strain effects. Analysis of the magnitude and anisotropy of the dislocation-induced broadening withhklindicates that the dislocations have a mixed screw/edge character and tend to form primarily on (111) slip planes parallel to the substrate at densities of ∼1015to 1016 m−2.

Diurnal variation in the quantitative EEG in healthy adult volunteers

AIMS

To define the change in power in standard waveband frequencies of quantitative cortical electroencephalogram (EEG) data over a 24 h period, in a drug free representative healthy volunteer population.

METHODS

This was an open, non randomised study in which 18 volunteers (9 male and 9 female) were studied on 1 study day, over a 24 h period. Volunteers had a cortical EEG recording taken at 0, 2, 4, 6, 8, 10, 12, 16 and 24 h. Each recording lasted for 6 min (3 min eyes open, 3 min eyes closed). All EEG recordings were taken in a quietened ward environment with the curtains drawn round the bed and the volunteer supine. During the 3 min eyes open, volunteers were asked to look at a red circle on a screen at the foot of the bed, and refrain from talking.

RESULTS

Plots produced of geometric mean power by time of the standard wave band frequencies gave some indication of a circadian rhythm over the 24 h period for theta (4. 75-6.75 Hz), alpha1 (7.0-9.5 Hz) and beta1 (12.75-18.50 Hz) wavebands. Mixed models were fitted to both the eyes open and eyes closed data which confirmed a change in mean waveband power with time with statistical significance at the conventional 5% level (P < 0.05).

CONCLUSIONS

These data indicate the presence of a diurnal variation in the cortical quantitative EEG. They support the use of a placebo control group when designing clinical trials which utilize quantitative EEG to screen for central nervous system (CNS) activity of pharmaceutical agents, to control for the confounding variable of time of day at which the EEG recordings were made.

A novel ryanodine receptor mutation and genotype-phenotype correlation in a large malignant hyperthermia New Zealand Maori pedigree

Malignant hyperthermia (MH) is a pharmacogenetic disorder that predisposes to a sometimes fatal hypermetabolic reaction to halogenated anaesthetics. MH is considered to originate from abnormal regulation of skeletal muscle Ca(2+) release. Current diagnosis of MH susceptibility (MHS) relies on in vitro contracture testing (IVCT) of skeletal muscle. The ryanodine receptor (RYR1) encoding the major Ca(2+) release channel in the skeletal muscle sarcoplasmic reticulum has been shown to be mutated in a number of MH pedigrees. The large Maori pedigree reported here is the largest MHS pedigree investigated to date and comprises five probands who experienced clinical episodes of MH and 130 members diagnosed by the IVCT. Sequencing of the 15 117 bp RYR1 cDNA in a MHS individual from this pedigree identified a novel C14477T transition that results in a Thr4826 to Ile substitution in the C-terminal region/transmembrane loop of the skeletal muscle ryanodine receptor. This is the first mutation in the RyR1 C-terminal region associated solely with MHS. Although linkage analysis showed strong linkage (max LOD, 11.103 at theta = 0.133) between the mutation and MHS in the pedigree using the standardized European IVCT phenotyping protocol, 22 MHS recombinants were observed. The relationship between the IVCT response and genotype was explored and showed that as IVCT diagnostic cut-off points were made increasingly stringent, the number of MHS discordants decreased with complete concordance between the presence or absence of the C14477T mutation and MHS and MH normal phenotypes, respectively, using a cut-off of 1.2 g tension at 2.0 mM caffeine and 1.8 g tension at 2.0% halothane. Many MHS pedigrees investigated have been excluded from linkage to the RYR1 gene on the basis of a small number of recombinants; however, the linkage analysis reported here suggests that other recombinant families excluded from linkage to the RYR1 gene may actually demonstrate linkage as the number of members tested within the pedigrees increases. The high number of discordants observed using the standardized diagnostic cut-off points is likely to reflect the presence of a second MHS susceptibility locus in the pedigree.

Prospective trial of preoperative concomitant boost radiotherapy with continuous infusion 5-fluorouracil for locally advanced rectal cancer

RATIONALE

To evaluate the response to a concomitant boost given during standard chemoradiation for locally advanced rectal cancer.

METHODS AND MATERIALS

Concomitant boost radiotherapy was administered preoperatively to 45 patients with locally advanced rectal cancer in a prospective trial. Treatment consisted of 45 Gy to the pelvis with 18 mV photons at 1.8 Gy/fraction using a 3-field belly board technique with continuous infusion 5FU chemotherapy (300mg/m(2)) 5 days per week. The boost was given during the last week of therapy with a 6-hour inter-fraction interval to the tumor plus a 2-3 cm margin. The boost dose equaled 7.5 Gy/5 fractions (1.5 Gy/fraction); a total dose of 52.5 Gy/5 weeks was given to the primary tumor. Pretreatment tumor stage, determined by endorectal ultrasound and CT scan, included 29 with T3N0 [64%], 11 T3N1, 1 T3Nx, 2 T4N0, 1 T4N3, and 1 with TxN1 disease. Mean distance from the anal verge was 5 cm (range 0-13 cm). Median age was 55 years (range 33-77 years). The population consisted of 34 males and 11 females. Median time of follow-up is 8 months (range 1-24 months).

RESULTS

Sphincter preservation (SP) has been accomplished in 33 of 42 (79%) patients resected to date. Three patients did not undergo resection because of the development of metastatic disease in the interim between the completion of chemoradiation (CTX/XRT) and preoperative evaluation. The surgical procedures included proctectomy and coloanal anastomosis (n = 16), low anterior resection (n = 13), transanal resection (n = 4). Tumor down-staging was pathologically confirmed in 36 of the 42 (86%) resected patients, and 13 (31%) achieved a pathologic CR. Among the 28 tumors (67%) located <6 cm from the anal verge, SP was accomplished in 21 cases (75%). Although perioperative morbidity was higher, toxicity rates during CTX/XRT were comparable to that seen with conventional fractionation. Compared to our contemporary experience with conventional CTX/XRT (45Gy; 1.8 Gy per fraction), improvements were seen in SP (79% vs. 59%; p = 0.02), SP for tumors <6 cm from the anal verge (75% vs. 42%; p = 0.003), and down-staging (86% vs. 62%; p = 0.003).

CONCLUSION

The SP rate with concomitant boost radiation has been highly favorable with rates of response which are higher than those previously reported for chemoradiation without administration of a boost. Further evaluation of this radiotherapeutic strategy appears warranted.

Toward designing the optimal total cavopulmonary connection: an in vitro study

BACKGROUND

Understanding the total cavopulmonary connection (TCPC) hemodynamics may lead to improved surgical procedures which result in a more efficient modified circulation. Reduced energy loss will translate to less work for the single ventricle and although univentricular physiology is complex, this improvement could contribute to improved postoperative outcomes. Therefore to conserve energy, one surgical goal is optimization of the TCPC geometry. In line with this goal, this study investigated whether addition of caval curvature or flaring at the connection conserves energy.

METHODS

TCPC models were made varying the curvature of the caval inlet or by flaring the anastomosis. Steady flow pressure measurements were made to calculate the power loss attributed to each connection design over a range of pulmonary flow splits (70:30 to 30:70). Particle flow visualization was performed for each design and was qualitatively compared to the power losses.

RESULTS

Results indicate that curving the cavae toward one pulmonary artery is advantageous only when the flow rate from that cavae matches the flow to the pulmonary artery. Under other pulmonary flow split conditions, the losses in the curved models are significant. In contrast, fully flaring the anastomosis reduced losses over the range of pulmonary flow splits. Power losses were 56% greater for the curving as compared to flaring. Fully flaring without caval offset reduced losses 45% when compared to previous models without flaring. If flaring on all sides was implemented with caval offset, power losses reduced 68% compared to the same nonflared model.

CONCLUSIONS

The results indicate that preferentially curving the cavae is only optimal under specific pulmonary flow conditions and may not be efficient in all clinical cases. Flaring of the anastomosis has great potential to conserve energy and should be considered in future TCPC procedures.

SMAD genes in juvenile polyposis

Juvenile polyposis (JP) is a dominantly inherited condition characterized by the development of multiple hamartomatous tumors, juvenile polyps, in the gastrointestinal tract. The aim of this study was to clarify the role of SMAD4 in JP. DNA from four unrelated JP kindreds and three sporadic JP cases was available for mutation screening. Two truncating defects (one in a familial and one in a sporadic case) and one missense change (in a familial case) that was absent in 55 control samples were detected. To study the possibility that germline mutations in other genes encoding different components of the TGF-beta signaling pathway may be present in these JP patients, mutation analyses of the SMAD2, SMAD3, and SMAD7 genes were also performed. No mutations of these genes were detected in any of the patients. Our results confirm that SMAD4 is a gene predisposing to JP and suggest the existence of further JP loci other than the SMAD2, SMAD3, or SMAD7 genes. Genes Chromosomes Cancer 26:54-61, 1999.

Electroencephalographic and psychomotor effects of chlorpromazine and risperidone relative to placebo in normal healthy volunteers

AIMS

To investigate the effects of single oral doses of chlorpromazine (50 mg) and risperidone (2 mg) relative to placebo on topographical electroencephalometry (CATEEMTM ) and psychomotor tests in 12 healthy male volunteers.

METHODS

A double-blind, placebo-controlled, three-way crossover design using a double dummy blinding technique was utilized. Chlorpromazine was selected as representative of the 'typical' neuroleptics, being also highly sedative. Risperidone has been suggested as representative of the newer 'atypical' neuroleptics and is claimed to be only minimally sedative. Volunteers were dosed on 3 separate days with a minimum of 7 days interval between trial days. On each trial day volunteers were dosed twice. Dose 1 consisting of either chlorpromazine 50 mg or placebo to chlorpromazine, and dose 2 either risperidone 2 mg or placebo to risperidone. The volunteers were randomized so that each received either chlorpromazine or risperidone (or neither), but not both on an individual trial day. A 17 electrode quantitative topographical electroencephalograph (EEG) recording was taken for each volunteer before and after each dosing period. Seven psychomotor function tests were used to determine the effects of each treatment on psychomotor performance.

RESULTS

The data confirm the cited reports of sedation following single oral doses of chlorpromazine 50 mg. However, 7 of the 12 volunteers dosed with risperidone 2 mg also reported drowsiness/lethargy which was of greater severity and duration than 5 of the 12 volunteers who reported somnolence following dosing with chlorpromazine 50 mg. Objective assessment of psychomotor impairment using a short battery of psychomotor function tests mirrored the subjective reports of somnolence in that the impairment in volunteers dosed with risperidone 2 mg was greater in extent and magnitude than in volunteers dosed with chlorpromazine 50 mg. With respect to the cortical quantitative electroencephalogram, both chlorpromazine (50 mg) and risperidone (2 mg) increased power (4.75-6.75 Hz) in keeping with cited effects of other neuroleptics on the quantitative EEG. In addition, there was a statistically significant increase (P<0.05) in alpha1 (7.0-9.5 Hz) and beta1 (12.75-18.5 Hz) wavebands in volunteers dosed with risperidone 2 mg. Furthermore, based on estimates of variability, we propose that a 3 min eyes open and 3 min eyes closed quantitative EEG recording is sufficient to maintain adequate power for this technique, whilst allowing its application to early volunteer trials of novel neuroleptic agents.

CONCLUSIONS

This study demonstrates that quantitative EEG can be utilized in the profiling of neuroleptic agents, and could be readily applied to the early profiling of novel neuroleptics in limited numbers of volunteers, early in drug development. The chosen battery of psychomotor tests has clearly demonstrable sensitivity to the quantification of the subjective reports of somnolence secondary to both chlorpromazine and risperidone.

Reduction in hMSH2 mRNA levels by premature translation termination: implications for mutation screening in hereditary nonpolyposis colorectal cancer

We have used single-strand conformational polymorphism (SSCP) and heteroduplex analysis to examine DNA from 50 colorectal carcinoma patients coming from families meeting the Amsterdam criteria for hereditary nonpolyposis colorectal cancer (HNPCC) or having developed colorectal carcinoma at age 45 or younger. We identified mutations in 12 of these patients, with seven of these being novel mutations. We examined four of the truncating mutations using in vitro transcription and translation (IVTT) assays and determined that the mutation causing an in-frame deletion of exon 5 could easily be detected by the IVTT assay, but the three mutations resulting in premature translation termination were not detected because the steady-state levels of the mutant allele transcripts are too low. Our findings suggest that some but not all mutant hMSH2 alleles have significantly lower steady-state mRNA levels than the normal allele. Under ideal circumstances, where lymphoblastoid cell lines are available for RNA extraction, IVTT may be useful for detecting truncating mutations. However, our data suggest that caution should be taken in using IVTT in routine screening of clinical samples for truncating HNPCC mutations, as many mutations may go undetected.

RNA binding by the novel helical domain of the influenza virus NS1 protein requires its dimer structure and a small number of specific basic amino acids

The RNA-binding/dimerization domain of the NS1 protein of influenza A virus (73 amino acids in length) exhibits a novel dimeric six-helical fold. It is not known how this domain binds to its specific RNA targets, one of which is double-stranded RNA. To elucidate the mode of RNA binding, we introduced single alanine replacements into the NS1 RNA-binding domain at specific positions in the three-dimensional structure. Our results indicate that the dimer structure is essential for RNA binding, because any alanine replacement that causes disruption of the dimer also leads to the loss of RNA-binding activity. Surprisingly, the arginine side chain at position 38, which is in the second helix of each monomer, is the only amino-acid side chain that is absolutely required only for RNA binding and not for dimerization, indicating that this side chain probably interacts directly with the RNA target. This interaction is primarily electrostatic, because replacement of this arginine with lysine had no effect on RNA binding. A second basic amino acid, the lysine at position 41, which is also in helix 2, makes a strong contribution to the affinity of binding. We conclude that helix 2 and helix 2', which are antiparallel and next to each other in the dimer conformation, constitute the interaction face between the NS1 RNA-binding domain and its RNA targets, and that the arginine side chain at position 38 and possibly the lysine side chain at position 41 in each of these antiparallel helices contact the phosphate backbone of the RNA target.

A web-based risk management and medical-legal curriculum for graduate medical education

An educational Web site on the topic of risk management and medical-legal issues was designed. The site incorporates a 25-question multiple-choice quiz where resident responses were stored in a database for quantitative analysis. Residents who browsed the educational module scored significantly higher on the quiz (81%) than those who did not (62%). The authors conclude that the Web site and accompanying quiz database offer a practical solution for the uniform delivery of risk management in graduate medical education.