Key enabling technologies for optical communications at 2000 nm

This paper discusses the potential for opening a new wavelength window at the 2 μm waveband for optical communications, showing current limitations of the system's performance. It focuses on novel results for key enabling technologies, including the analysis of laser injection locking at this waveband, an improved responsivity for bulk and strained InGaAs edge-couple detectors, and also an increased gain profile for thulium-doped fiber amplifiers.

Central venous Access device SeCurement And Dressing Effectiveness for peripherally inserted central catheters in adult acute hospital patients (CASCADE): a pilot randomised controlled trial

Background

Peripherally inserted central catheters (PICCs) are commonly used for delivering intravenous therapy. PICC failure is unacceptably high (up to 40%) due to mechanical, infectious and thrombotic complications. Poor securement potentiates all complication types. This randomised controlled trial (RCT) aimed to examine the feasibility of a large RCT of four dressing and securement methods to prevent PICC failure.

Methods

This single-centre pilot RCT included 124 admitted medical/surgical/cancer patients aged ≥ 16 years with a PICC. Interventions were: (i) standard polyurethane dressing and sutureless securement device (SPU + SSD, control); (ii) polyurethane with absorbent lattice pad dressing (PAL + Tape); (iii) combination securement-dressing (CSD); and (iv) tissue adhesive (TA + SPU). All groups except TA + SPU had a chlorhexidine-gluconate (CHG) impregnated disc. Feasibility outcomes were recruitment and safety/acceptability of the interventions. The primary outcome was PICC failure, a composite of PICC removal for local infection, catheter-associated bloodstream infection, dislodgement, occlusion, and/or catheter fracture. Secondary outcomes included individual complications, dressing failure and dwell time, PICC dwell time, skin complications/phlebitis indicators, product costs, and patient and staff satisfaction. Qualitative feedback was also collected.

Results

PICC failure incidence was: PAL + CHG + Tape (1/5; 20%; 17.4/1000 days), SPU + SSD + CHG (control) (4/39; 10%; 9.0/1000 days), TA + SPU (3/35; 9%; 9.6/1000 days), and CSD + CHG (3/42; 7%; 9.4/1000 days). Recruitment to PAL + CHG + Tape was ceased after five participants due to concerns of PICC dislodgement when removing the dressing. CSD + CHG, TA + SPU (TA applied only at PICC insertion time), and control treatments were acceptable to patients and health professionals.

Conclusion

A large RCT of CSD + CHG and TA + SPU (but not PAL + CHG + Tape) versus standard care is feasible.

Trial registration

Australian and New Zealand Clinical Trials Registry, ACTRN12616000027415. Registered on 15 January 2016.

Who wants to be an acute medic? A survey of junior doctors attitudes towards and beliefs surrounding a career in acute medicine

AIM

Survival of Acute Medicine (AM) depends on successful recruitment. Local juniors were unaware of training requirements and opportunities in AM. We conducted a survey to establish whether this was a nationwide issue.

METHODS

A survey was distributed nationally with participants responding to statements on a Likert Scale.

RESULTS

397 responses from four deaneries were received. 50% of respondents were unaware of AM training opportunities. 20% of juniors did not know of entry requirements for training. Juniors felt that becoming a medical registrar would discourage them from careers in AM.

DISCUSSION

This study reveals poor awareness of training opportunities in AM and reluctance to pursue the medical registrar role, which is unrelated to confidence in dealing with acute medical emergencies. Promotional work will be invaluable in future workforce planning.

Distrust in the healthcare system and organ donation intentions among African Americans

The purpose of this study is to further understanding of the association between distrust in the healthcare system and written and verbal expressions of donation intentions among African Americans. We hypothesize that distrust in the healthcare system will be significantly, positively associated with both verbal and written donation intentions. Five hundred and eighty five participants completed a 98-item survey that included scales on distrust in the healthcare system and donation intentions. Bivariate analyses (t-tests, ANOVA, chi-square tests and odds ratios) were used to explore the extent to which donation intentions and distrust in the healthcare system varied by demographic characteristics and the association between the distrust in the healthcare system scale and verbal and written donation intentions. Separate logistic regressions were performed with each of the dependent variables to see if significant associations remained while controlling for confounders. Findings based on the multiple regression indicate that when controlling the participant's education level, distrust in the healthcare system was not significantly related to written donation intentions (OR = 1.04; P = .12). When controlling for education level, health insurance status, Community Health Advocates group and marital status, distrust in the healthcare system was significantly associated with verbal donation intentions (OR = 1.08; P < 0.05). Our results suggest that distrust in the healthcare system varies in the way that it is associated with donation intentions. Future organ donation studies should be conducted to determine the pathways through which distrust in the healthcare system impacts different types of organ donation intentions.

Residential racial composition, spatial access to care, and breast cancer mortality among women in Georgia

We explored the association between neighborhood residential racial composition and breast cancer mortality among Black and White breast cancer patients in Georgia and whether spatial access to cancer care mediates this association. Participants included 15,256 women living in 15 metropolitan statistical areas in Georgia who were diagnosed with breast cancer between 1999 and 2003. Residential racial composition was operationalized as the percent of Black residents in the census tract. We used gravity-based modeling methods to ascertain spatial access to oncology care. Multilevel Cox proportional hazards models and mediation analyses were used to test associations. Black women were 1.5 times more likely to die from breast cancer than White women. Residential racial composition had a small but significant association with breast cancer mortality (hazard ratios [HRs] = 1.04-1.08 per 10% increase in the percent of Black tract residents). Individual race did not moderate this relationship, and spatial access to care did not mediate it. Residential racial composition may be part of the socioenvironmental milieu that produces increased breast cancer mortality among Black women. However, there is a lack of evidence that spatial access to oncology care mediates these processes.

DISC1 exon 11 rare variants found more commonly in schizoaffective spectrum cases than controls

We previously performed a linkage study using families identified through probands meeting criteria for DSM-IV schizoaffective disorder, bipolar type (SABP) and observed a genome-wide significant signal (LOD = 3.54) at chromosome 1q42 close to DISC1. An initial sequencing study of DISC1 using 14 unrelated DSM-IV SABP samples from the linkage study identified 2 non-synonymous coding SNPs in exon 11 in 2 separate individuals. Here we provide evidence of additional rare coding SNPs within exon 11. In sequencing exon 11 in 506 cases and 1,211 controls for variants that occurred only once, 4 additional rare variants were found in cases (P-value = 0.008, Fisher's exact trend test).

The bipolar disorder risk allele at CACNA1C also confers risk of recurrent major depression and of schizophrenia

Molecular genetic analysis offers opportunities to advance our understanding of the nosological relationship between psychiatric diagnostic categories in general, and the mood and psychotic disorders in particular. Strong evidence (P=7.0 × 10(-7)) of association at the polymorphism rs1006737 (within CACNA1C, the gene encoding the α-1C subunit of the L-type voltage-gated calcium channel) with the risk of bipolar disorder (BD) has recently been reported in a meta-analysis of three genome-wide association studies of BD, including our BD sample (N=1868) studied within the Wellcome Trust Case Control Consortium. Here, we have used our UK case samples of recurrent major depression (N=1196) and schizophrenia (N=479) and UK non-psychiatric comparison groups (N=15316) to examine the spectrum of phenotypic effect of the bipolar risk allele at rs1006737. We found that the risk allele conferred increased risk for schizophrenia (P=0.034) and recurrent major depression (P=0.013) with similar effect sizes to those previously observed in BD (allelic odds ratio ∼1.15). Our findings are evidence of some degree of overlap in the biological underpinnings of susceptibility to mental illness across the clinical spectrum of mood and psychotic disorders, and show that at least some loci can have a relatively general effect on susceptibility to diagnostic categories, as currently defined. Our findings will contribute to a better understanding of the pathogenesis of major psychiatric illness, and such knowledge should be useful in providing an etiological rationale for shaping psychiatric nosology, which is currently reliant entirely on descriptive clinical data.

Genetic utility of broadly defined bipolar schizoaffective disorder as a diagnostic concept

BACKGROUND

Psychiatric phenotypes are currently defined according to sets of descriptive criteria. Although many of these phenotypes are heritable, it would be useful to know whether any of the various diagnostic categories in current use identify cases that are particularly helpful for biological-genetic research.

AIMS

To use genome-wide genetic association data to explore the relative genetic utility of seven different descriptive operational diagnostic categories relevant to bipolar illness within a large UK case-control bipolar disorder sample.

METHOD

We analysed our previously published Wellcome Trust Case Control Consortium (WTCCC) bipolar disorder genome-wide association data-set, comprising 1868 individuals with bipolar disorder and 2938 controls genotyped for 276 122 single nucleotide polymorphisms (SNPs) that met stringent criteria for genotype quality. For each SNP we performed a test of association (bipolar disorder group v. control group) and used the number of associated independent SNPs statistically significant at P<0.00001 as a metric for the overall genetic signal in the sample. We next compared this metric with that obtained using each of seven diagnostic subsets of the group with bipolar disorder: Research Diagnostic Criteria (RDC): bipolar I disorder; manic disorder; bipolar II disorder; schizoaffective disorder, bipolar type; DSM-IV: bipolar I disorder; bipolar II disorder; schizoaffective disorder, bipolar type.

RESULTS

The RDC schizoaffective disorder, bipolar type (v. controls) stood out from the other diagnostic subsets as having a significant excess of independent association signals (P<0.003) compared with that expected in samples of the same size selected randomly from the total bipolar disorder group data-set. The strongest association in this subset of participants with bipolar disorder was at rs4818065 (P = 2.42 x 10(-7)). Biological systems implicated included gamma amniobutyric acid (GABA)(A) receptors. Genes having at least one associated polymorphism at P<10(-4) included B3GALTS, A2BP1, GABRB1, AUTS2, BSN, PTPRG, GIRK2 and CDH12.

CONCLUSIONS

Our findings show that individuals with broadly defined bipolar schizoaffective features have either a particularly strong genetic contribution or that, as a group, are genetically more homogeneous than the other phenotypes tested. The results point to the importance of using diagnostic approaches that recognise this group of individuals. Our approach can be applied to similar data-sets for other psychiatric and non-psychiatric phenotypes.

Sub-threshold manic symptoms in recurrent major depressive disorder are a marker for poor outcome

OBJECTIVE

A small but significant proportion of patients with major depressive disorder (MDD) report mild manic symptoms which are below the diagnostic threshold for a hypomanic episode.

METHOD

We tested for an association between sub-threshold manic symptoms and clinical outcome in almost 600 patients with recurrent MDD who also had no known family history of bipolar disorder.

RESULTS

9.6% of this large sample had a life-time history of sub-threshold manic symptoms. These patients were significantly more likely to have a history of poor response to antidepressants (OR 2.84; 95% CI 1.23-6.56; P < 0.02) and more likely to have experienced psychosis (OR 2.07; 95% CI 1.05-4.09; P < 0.04). They had also experienced more depressive episodes on average (P = 0.006) and were more likely to have been admitted to hospital (P < 0.03).

CONCLUSION

Sub-threshold manic symptoms in patients with recurrent MDD may be a useful clinical marker for poor response to antidepressants and a more morbid long-term clinical course.