Magnification in undergraduate endodontic teaching in the UK and Ireland: a survey of teaching leads in Endodontology.

AIM: To investigate the use of magnification in undergraduate endodontic teaching in dental schools within the UK and Ireland and identify factors that may impact on levels of adoption. METHODOLOGY: An electronic questionnaire was distributed to teaching leads in undergraduate endodontics in all UK and Ireland dental schools. RESULTS: Completed questionnaires were received from 15 of 18 course leads. The study revealed magnification is not universally embedded within the undergraduate curricula, and the majority of schools had no expectation for students to use magnification, although it was encouraged. The study provided insight into teaching staff factors, student factors and institutional factors that impact upon the adoption of magnification in undergraduate endodontic teaching. Although course leads utilized magnification in their own practice, this did not translate into institutional expectation for students to use magnification. Barriers to adoption of such an institutional expectation included cost and lack of staff training. CONCLUSIONS: Magnification has become viewed as an essential part of endodontic practice. The dental operating microscope has the most significant impact on endodontic visualization; however, the use of dental loupes in nonsurgical endodontics could be considered the minimum standard. The pedagogical dilemma faced by dental educators training undergraduates to behave in a manner that they themselves would not, cannot be rationalized on the basis of cost and lack of staff training. It is proposed that although significant, these barriers are not insurmountable and the use of dental loupe should become an expectation in undergraduate training in the UK and Ireland.

The undivided patient: a retrospective cohort analysis of specialty referrals made from inpatient general medical units comparing regional to metropolitan practice.

BACKGROUND: In an era of growing subspecialisation there has been significant research into the role, determinants and outcomes of outpatient referrals but very little on inpatient specialty referrals from general medical units. AIMS: This study aims to describe and compare the rate of specialty referrals from inpatient general medical units in a regional general and a metropolitan tertiary hospital, and review associated outcomes. METHODS: Retrospective cohort analysis of general medical admissions over the 10-week period extending from 28 March to 5 June 2011. Two hospitals were included in the study; West Gippsland Hospital (WGH) and Monash Medical Centre (MMC). For all admissions, details of patient demographics, episode of care and number of inpatient referrals made per admission were extracted from the medical records. Rates and outcomes of inpatient referrals were calculated and compared. RESULTS: There were 116 admissions to MMC and 108 (107 available for analysis) to WGH during the study period. There were no significant differences in patient demographics between the two sites. However, there were significantly fewer active conditions (2.87 vs 4.01, P < 0.01), fewer specialty fields represented (2.50 vs 3.51, P < 0.01) and fewer specialty referrals made per admission at WGH compared with MMC (0.69 vs 1.74, P < 0.01). The referral rate per diagnosis and the rate of referrals per specialty field represented were significantly higher at MMC compared with WGH (P < 0.01). CONCLUSION: This preliminary study suggests that patients admitted to rural hospital general medical units have fewer active conditions with fewer specialty referrals made per admission, compared with a comparator metropolitan hospital general medical unit. Further research is required to investigate the reasons for such differences and implications for policy and practice.

Dengue virus serotypes in Jamaica, 2003-2007.

BACKGROUND: Dengue virus (DENV) infection is increasing in prevalence and severity globally. The severity of dengue is influenced by several factors including the immune response, viral and host genetic factors. METHOD: The DENV serotypes were determined in 770 serum samples from dengue immunoglobulin (Ig) M antibody positive (n = 469), dengue IgM negative (n = 185) and dengue antibody negative (n = 116) patients with suspected dengue who presented during (n = 150) or after (n = 620) the acute phase of illness during 2003-2007. Dengue antibodies were detected by enzyme-linked immunosorbent assays and DENV RNA by reverse transcriptase-polymerase chain reaction (RT-PCR) performed on serum and cell culture supernatants of C6/36 mosquito cells inoculated with acute phase serum (n = 150). RESULTS: Based on serological profiles, 41% of acute phase sera and 66% of post acute sera were from patients with current primary or secondary dengue, while 41% and 35% of acute and post-acute phase sera, respectively, were from patients with secondary dengue or past exposure only. Dengue virus RNA was found in 20/770 samples (2.6%). Only 1.5% (9/620) of sera collected after the acute phase of illness tested positive for DENV RNA compared with 2.6% (4/150) of sera collected during the acute phase and 7.3% of cell culture supernatants inoculated with acute phase serum (11/150, p = 0.001). All four serotypes including DENV-1 (3/20, 15%), DENV-2 (7/20, 35%), DENV-3 (3/20, 15%) and DENV-4 (7/20, 35%) were identified over the five-year period. These results also showed that DENV-1, 2 and 4 were present during 2007 and that DENV-2 and DENV- 4 were the likely causative viruses of the 2007-2008 dengue outbreak in Jamaica. The three strains of DENV-3 were isolated from infants less than three years of age with primary infection during 2006. CONCLUSION: This study highlights the increasing threat of dengue and severe dengue disease to the Jamaican population. Preventative measures including laboratory surveillance and vector control should be strictly maintained at the highest level.

Molecular epidemiology of dengue in Jamaica dengue virus genotypes in Jamaica, 2007.

The genotypes of dengue viruses (DENV) isolated from patients with dengue in Jamaica during 2007 were determined using DNA sequencing and phylogenetic analysis of the C-prM gene junction. The 17 DENV analysed included strains of DENVserotypes 1 (DENV-1, n = 3), DENV-2 (n = 7) and DENV-4 (n = 7). All strains ofDENV-1 were classified as genotype III, while 1 of 7 strains of DENV-2 belonged to the Asian American/Asian genotype, genotype I/III (Jamaica genotype), 2 were genotype V, the American genotype and 4 strains clustered with reference strains belonging to genotype IV. The 6 DENV-4 strains from Jamaica and the control strain clustered together in a separate clade from Caribbean/American reference strains, which belong to genotype II and Asian strains, classified as genotypes I and III. There has been little evolution in the DENV-1 strains circulating in Jamaica over the years and this might reduce the risk of outbreaks due to this serotype. In contrast, the high genetic diversity in strains of DENV-2 viruses in circulation, the presence of more recently introduced genotypes and a new clade of DENV-4 might contribute to the epidemic potential of these DENV serotypes. These preliminary data clearly indicate the need to maintain laboratory surveillance, and other control measures against hyperendemicity of dengue in Jamaica.

Dengue HLA associations in Jamaicans.

BACKGROUND: Polymorphisms in the human leukocyte antigen (HLA) genes might predispose certain individuals to dengue fever (DF) and the severe forms of the disease: dengue haemorrhagic fever/ dengue shock syndrome (DHF/DSS). SUBJECTS AND METHOD: A DNA-based HLA typing method was used to determine the HLA class I and II alleles in 50 patients with dengue, including 45 cases of DF 5 cases of DHF and 177 healthy individuals in Jamaica. RESULTS: HLA-A*24 and - DRbeta5*01/02 were significantly associated with dengue infection while possession of HLA-A*23, -CW*04, -DQbeta*02, -DQbeta*03 and DQbeta*06 were protective. No other significant associations were found after correction for the number of alleles tested at each HLA-locus. CONCLUSION: This is the first study to report a significant association with HLA-A*24 and DF although this allele is associated with DHF and DSS in Vietnamese patients. The other HLA associations observed in the Jamaican cohort also are different from those reported in other ethnic groups. Further studies which involve larger numbers of patients with DHF and explore functional aspects of HLA allelic associations with dengue in Jamaicans are necessary.

Disease progression among multiple sclerosis patients before and during a disease-modifying drug program: a longitudinal population-based evaluation.

Randomized controlled trials have demonstrated the efficacy of disease-modifying drugs (DMDs) in persons with relapsing-remitting multiple sclerosis (MS) and secondary progressive MS with superimposed relapses. However, these brief studies of selected patients have focused mainly on reducing attacks and must be complemented by evaluations in 'realworld' clinical settings to establish the effectiveness of DMD programs in slowing disease progression and to inform health policy and program decision-making. We assessed the effectiveness of DMDs as administered in a comprehensive publicly funded drug insurance program that provides DMDs to a geographically defined population of MS patients who meet specific eligibility criteria. Data from 1752 MS patients (10,312 assessments) seen between 1980 and 2004 at a regional MS Clinic serving the entire population of Nova Scotia, Canada were analysed. Using survival methods we observed a statistically significant reduction in disease progression to specific Expanded Disability Status Scale endpoints following the introduction of this program. Subgroup analyses of patients eligible for treatment using hierarchical linear regression methods also suggested that disease progression was slowed in patients treated with the first DMD prescribed. These findings provide evidence supporting DMD program effectiveness that can be used to inform the broader implementation of such programs.

How effective are disease-modifying drugs in delaying progression in relapsing-onset MS?

OBJECTIVE: Our objective was to estimate the effectiveness of disease-modifying drugs (DMDs) in delaying multiple sclerosis (MS) disability progression in relapsing-onset (R-onset) definite MS patients under "real-world" conditions. METHODS: Treatment effect size, for DMDs as a class, was estimated in absolute terms and relative to MS natural history. A basic model estimated annual Expanded Disability Status Scale (EDSS) change before and after treatment. An expanded model estimated annual EDSS change in pretreatment years, treatment years on first drug, treatment years after drugs were switched, and in years after treatment stopped. Models were populated with 1980 through 2004 clinical data, including 1988 through 2004 data for all Nova Scotians treated with DMDs. Estimates were made for relapsing-remitting MS (RRMS), secondary progressive MS (SPMS), and R-onset groups. RESULTS: Estimated pretreatment annual EDSS increases were approximately 0.10 of one EDSS point for the RRMS group, 0.31 for the SPMS group, and 0.16 for the R-onset group. Estimates of EDSS increase avoided per treatment year on the first drug were significant for the RRMS group (-0.103, 0.000), the SPMS group (-0.065, 0.011), and the R-onset group (-0.162, 0.000); relative effect size estimates were 112%, 21%, and 105%. Estimated EDSS progression was faster in years after drug switches and treatment stops. CONCLUSIONS: Our estimates of disease-modifying drug (DMD) relative treatment effect size, in the context of "real-world" clinical practice, are similar to DMD treatment efficacy estimates in pivotal trials, though our findings attained statistical significance. DMDs, as a class, are effective in delaying Expanded Disability Status Scale progression in patients with relapsing-onset definite multiple sclerosis (MS) (90%), although effectiveness is much better for relapsing-remitting MS than for secondary progressive MS groups.

Day case laparoscopic cholecystectomy is safe and feasible: a case controlled study.

BACKGROUND: Day case laparoscopic cholecystectomy (DC-LC) is being practised in the USA and at sporadic centres in the UK including our department. The aim was to evaluate the admission rate after DC-LC. PATIENTS AND METHODS: Prospectively collected data was analysed retrospectively. The case notes of all patients were retrieved from the medical records and reviewed individually. Inclusion criteria for DC-LC were cholelithiasis, non-acute cholecystitis, ASA I-III and informed consent. Standard laparoscopic cholecystectomy was performed. All patients had anti-DVT prophylaxis (pneumatic compression and enoxaparin), per-operative antibiotic, oro-gastric tube, paracetamol suppository and local anaesthetic to all wounds. They were discharged the same day. The end point was 6-week follow-up (86% overall). RESULTS: Over a 32-month period, 164 consecutive patients with symptomatic cholelithiasis and ASA score of III or less were included. M:F was 1:5 and median age 45y. There were two conversions. The direct admission rate (DAR) was 26/164 (14%). The indication for direct admission included observation alone (7/26), wound pain (6/26), nausea (3/26), suction drain (2/26) and operation in the afternoon (2/26). Six (3.6%) required re-admission. One had a cystic artery pseudo-aneurysm presenting with colonic bleeding and another with an injury to CBD. One had post-operative mild pancreatitis and three had wound pain and bruising. Fourteen out of 41 were admitted in the >55y age group compared to 12/123 from <55y age group (p=0.00054). CONCLUSION: DC-LC is safe and feasible in non-acute patients with symptomatic cholelithiasis. Over-55y age group had a higher chance of admission, mainly due to caution.

Robust transport barriers resulting from strong Kolmogorov-Arnold-Moser stability.

Hamiltonian systems that locally violate the twist condition arise in many applications. Numerical simulations reveal that, when systems of this type are perturbed, the degenerate or nontwist tori are remarkably stable. This phenomenon, which we refer to as strong Kolmogorov-Arnold-Moser (KAM) stability, is shown to be linked to very small resonance widths near degenerate tori. Quantitative estimates of degenerate resonance widths are derived and bifurcations of degenerate resonances are described. Strong KAM stability leads to robust transport barriers, which are important in all of the many applications in which Hamilitonians with the nontwist property arise.

Inflamed solitary caecal diverticulum - it is not appendicitis, what should I do?

We describe three cases that presented with symptoms suggestive of appendicitis but were found at operation to have an inflamed solitary caecal diverticulum. All were treated successfully with diverticulectomy or inversion of the diverticulum. We wish to highlight this diagnosis and its surgical management so that informed decisions can be made if this is first encountered in the operating theatre.

Ambulatory laparoscopic cholecystectomy outcomes.

BACKGROUND: Outpatient laparoscopic cholecystectomy is an established practice in the United States, but it is not well established in the United Kingdom, and evidence of experience is scarce. The aim of this study was to evaluate the effect of ambulatory laparoscopic cholecystectomy on postoperative morbidity and possible cost savings. We tried to elucidate possible predictors of unplanned admission and readmission rates after discharge. METHODS: This study was conducted in 2 phases. The first phase involved 112 patients and was a retrospective analysis from January 2002 to July 2003 (19 months). The second was a prospective study involving 86 patients from August 2003 to April 2005 (21 months). Consultants, associate specialists, or higher surgical trainees performed the surgeries in a dedicated outpatient procedure unit. The study ended 6 weeks after the operation. RESULTS: Hospital mortality was zero. Overall, 29 (15%) patients required unplanned admissions. Three (1.5%) patients required conversion to open cholecystectomy. Other causes included simple observations (7), wound pain (6), nausea and vomiting (6), suction drain (2), urinary retention (2), operation in the afternoon (2), and shoulder pain (1). Of the patients discharged, 7 (3.5%) required readmission after the initial discharge. Five of the 7 readmissions were wound related and treated conservatively. Two patients underwent laparotomy. CONCLUSION: Ambulatory laparoscopic cholecystectomy appears to be safe, feasible, and cost-effective with a low conversion rate. The unplanned admission rate can be reduced by better training, criteria for discharge, and improvement in anesthesia. This will have implications for surgical training and healthcare resources.

Persistent transport barrier on the West Florida Shelf.

Analysis of drifter trajectories in the Gulf of Mexico has revealed the existence of a region on the southern portion of the West Florida Shelf (WFS) that is not visited by drifters that are released outside of the region. This so-called "forbidden zone" (FZ) suggests the existence of a persistent cross-shelf transport barrier on the southern portion of the WFS. In this letter a year-long record of surface currents produced by a Hybrid-Coordinate Ocean Model simulation of the WFS is used to compute Lagrangian coherent structures (LCSs), which reveal the presence of a persistent cross-shelf transport barrier in approximately the same location as the boundary of the FZ. The location of the cross-shelf transport barrier undergoes a seasonal oscillation, being closer to the coast in the summer than in the winter. A month-long record of surface currents inferred from high-frequency (HF) radar measurements in a roughly 60 km × 80 km region on the WFS off Tampa Bay is also used to compute LCSs, and these also reveal the presence of transient transport barriers. While the HF-radar-derived transport barriers cannot be unambiguously linked to the boundary of the FZ, this analysis does demonstrate the feasibility of monitoring transport barriers on the WFS using a HF-radar-based measurement system. The implications of a persistent cross-shelf transport barrier on the WFS for the development of harmful algal blooms on the shoreward side of the barrier are considered.

A comparison of health utility measures for the evaluation of multiple sclerosis treatments.

OBJECTIVES: To evaluate the practical application and psychometric properties of three health utility measures in a sample of MS patients with a broad range of neurological disability as measured by the Extended Disability Status Scale (EDSS). METHODS: Patients randomly selected from two MS clinic registries were assessed using standard clinical methods and completed three generic measures of health utility (EQ-5D, HUI Mark III, SF-6D). The proportion of missing data, test/retest reliability, and construct validity of each health utility measure were examined. RESULTS: The assessments were completed by 187 patients. Less than 10% of data were missing for the subscales of the SF-6D (< 3.2%), HUI Mark III (<1.6%), and EQ-5D (< or =7.5%). Severely disabled patients were more likely to omit physical function questions for the SF-6D (20%), and EQ-5D (43%). Retest reliability for the SF-6D (ICC = 0.83), EQ-5D (ICC = 0.81), and HUI Mark III (ICC = 0.87) were adequate for population surveys. Correlations between assessment of clinical function and each health utility measure were strongest for the HUI Mark III (HUI Mark III EDSS rho = -0.77, HUI Mark III ambulation index rho = -0.76, HUI Mark III timed 25 foot walk rho = -0.73, HUI Mark III nine hole peg test rho = -0.65). CONCLUSIONS: The health utility measures were generally feasible and reliable but the HUI Mark III demonstrated highest concordance with the EDSS across the full range of neurological disability. Of the three measures studied, the HUI Mark III may be the most appropriate for cost effectiveness evaluations of MS therapies.

Ray stability in weakly range-dependent sound channels.

Ray stability is investigated in environments consisting of a range-independent background sound-speed profile on which a range-dependent perturbation is superimposed. Theoretical arguments suggest and numerical results confirm that ray stability is strongly influenced by the background sound speed profile. Ray instability is shown to increase with increasing magnitude of alpha(I)=(I/omega)d omega/dI, where 2pi/omega(I) is the range of a ray double loop and I is the ray action variable. This behavior is illustrated using internal-wave-induced scattering in deep ocean environments and rough surface scattering in upward refracting environments.

Natural killer gene complex (Nkc) allelic variability in inbred mice: evidence for Nkc haplotypes.

Allelic variability for mouse Chromosome 6 Nkc loci was assessed in 22 common laboratory strains of mice using selected natural killer gene complex (Nkc)-linked sequence tagged site markers. Most Nkc markers distinguished three or more alleles for a particular locus in the assessed mouse strains. Nkc locus alleles were highly conserved among genealogically related inbred strains, whereas far less similarity was observed among unrelated strains. Concurrent strain-to-strain comparisons for all Nkc-linked loci revealed common and uncommon Nkc haplotypes, including some that were likely recombinant. Nkc allele and haplotype assignments in inbred mouse strains and correlation with phenotypic traits should facilitate positional gene cloning strategies for unknown Nkc-linked trait modification loci.

Hydrogen bond breaking dynamics of the water trimer in the translational and librational band region of liquid water.

The effect of exciting each of the three classes of intermolecular vibrations on the hydrogen bond lifetime (tau(H)) of the isolated water trimer is investigated by far-infrared laser spectroscopy. Single excitation of a librational vibration decreases tau(H) by 3 orders of magnitude to tau(H) = 1-6 ps, comparable to the time scale of a number of important bulk water dynamical relaxation processes. In contrast, excitation of translational or torsional vibrations has no significant effect (tau(H) = 1-2 ns). Although such a dependence of tau(H) on intermolecular motions has also been proposed for liquid water via computer simulations, these are the first experiments that provide a detailed molecular picture of the respective motions without extensive interpretation.

Water at hydrophobic surfaces: weak hydrogen bonding and strong orientation effects.

Vibrational studies that selectively probe molecular structure at CCl4/H2O and hydrocarbon/H2O interfaces show that the hydrogen bonding between adjacent water molecules at these interfaces is weak, in contrast to generally accepted models of water next to fluid hydrophobic surfaces that suggest strong hydrogen bonding. However, interactions between these water molecules and the organic phase result in substantial orientation of these weakly hydrogen-bonded water molecules in the interfacial region. The results have important implications for understanding water adjacent to hydrophobic surfaces and the penetration of water into hydrophobic phases.

Vital involvement of a natural killer cell activation receptor in resistance to viral infection.

Natural killer (NK) cells are lymphocytes that can be distinguished from T and B cells through their involvement in innate immunity and their lack of rearranged antigen receptors. Although NK cells and their receptors were initially characterized in terms of tumor killing in vitro, we have determined that the NK cell activation receptor, Ly-49H, is critically involved in resistance to murine cytomegalovirus in vivo. Ly-49H requires an immunoreceptor tyrosine-based activation motif (ITAM)-containing transmembrane molecule for expression and signal transduction. Thus, NK cells use receptors functionally resembling ITAM-coupled T and B cell antigen receptors to provide vital innate host defense.