Low-noise φ-OTDR employing nonlinear optical preamplification for distributed acoustic sensing

A phase sensitive optical time domain reflectometry sensing scheme employing a two-stage nonlinear optical preamplification system is proposed to reduce the blind spot effect in Rayleigh scattering by improving the optical power distribution and to enhance the resolution at locations of low-backscatter intensity measurements, providing a higher signal-to-noise ratio for distributed acoustic measurements; the developed system has been tested in-laboratory and on in-field monitoring of a survey well in Cottessen, The Netherlands. The characterization shows strain noise levels below 1 nɛ for a 10 kHz sampling rate.

IMPACT OF THE COVID-19 PANDEMIC ON PUBLIC HOSPITALS IN THE UNITED STATES

The country's public hospitals, guided by the principles established by the first such hospital in 1736 and codified through the policies of the Surgeon General in 1936, have played an outsized role as safety net institutions for disadvantaged populations. Public hospitals are predominantly located in urban, under-resourced neighborhoods and treat a larger percentage of low-income individuals who are uninsured or enrolled in Medicaid. In assessing the status of public hospitals and urban communities in the twenty-first century, the impact of the COVID-19 pandemic was evaluated at two high-performing public hospitals, Grady Memorial Hospital and Rush University Medical Center, and a network of safety hospitals affiliated with the Missouri Hospital Association. COVID-19 infections and death rates stratified by race and ethnicity were examined. The results suggest a trend toward lower mortality in African American patients in the first year of the pandemic and possible adverse outcomes in a subset of rural hospitals in Missouri. This study highlights the need to expand funding and support for the nation's essential hospitals.

A highly virulent variant of HIV-1 circulating in the Netherlands

We discovered a highly virulent variant of subtype-B HIV-1 in the Netherlands. One hundred nine individuals with this variant had a 0.54 to 0.74 log₁₀ increase (i.e., a ~3.5-fold to 5.5-fold increase) in viral load compared with, and exhibited CD4 cell decline twice as fast as, 6604 individuals with other subtype-B strains. Without treatment, advanced HIV-CD4 cell counts below 350 cells per cubic millimeter, with long-term clinical consequences-is expected to be reached, on average, 9 months after diagnosis for individuals in their thirties with this variant. Age, sex, suspected mode of transmission, and place of birth for the aforementioned 109 individuals were typical for HIV-positive people in the Netherlands, which suggests that the increased virulence is attributable to the viral strain. Genetic sequence analysis suggests that this variant arose in the 1990s from de novo mutation, not recombination, with increased transmissibility and an unfamiliar molecular mechanism of virulence.

Multiform antimicrobial resistance from a metabolic mutation

A critical challenge for microbiology and medicine is how to cure infections by bacteria that survive antibiotic treatment by persistence or tolerance. Seeking mechanisms behind such high survival, we developed a forward-genetic method for efficient isolation of high-survival mutants in any culturable bacterial species. We found that perturbation of an essential biosynthetic pathway (arginine biosynthesis) in a mycobacterium generated three distinct forms of resistance to diverse antibiotics, each mediated by induction of WhiB7: high persistence and tolerance to kanamycin, high survival upon exposure to rifampicin, and minimum inhibitory concentration-shifted resistance to clarithromycin. As little as one base change in a gene that encodes, a metabolic pathway component conferred multiple forms of resistance to multiple antibiotics with different targets. This extraordinary resilience may help explain how substerilizing exposure to one antibiotic in a regimen can induce resistance to others and invites development of drugs targeting the mediator of multiform resistance, WhiB7.

Waveguide-based absorption measurement system for visible wavelength applications

We present a miniaturized waveguide-based absorption measurement system operating at a wavelength of 635 nm, based on a silicon nitride integrated photonic platform, suitable for lab-on-chip applications. We experimentally demonstrate a high correlation between the bulk dye concentration and the measured absorption loss levels in the waveguides. We explain a photonic design process for choosing the ideal waveguide to minimize the coefficient of variation on the analyte concentration. The approach is designed for camera readout, allowing multiple readouts and easy integration for lab-on chip cartridge approach.

Whole Cell Active Inhibitors of Mycobacterial Lipoamide Dehydrogenase Afford Selectivity over the Human Enzyme through Tight Binding Interactions

Tuberculosis remains a leading cause of death from a single bacterial infection worldwide. Efforts to develop new treatment options call for expansion into an unexplored target space to expand the drug pipeline and bypass resistance to current antibiotics. Lipoamide dehydrogenase is a metabolic and antioxidant enzyme critical for mycobacterial growth and survival in mice. Sulfonamide analogs were previously identified as potent and selective inhibitors of mycobacterial lipoamide dehydrogenase in vitro but lacked activity against whole mycobacteria. Here we present the development of analogs with improved permeability, potency, and selectivity, which inhibit the growth of Mycobacterium tuberculosis in axenic culture on carbohydrates and within mouse primary macrophages. They increase intrabacterial pyruvate levels, supporting their on-target activity within mycobacteria. Distinct modalities of binding between the mycobacterial and human enzymes contribute to improved potency and hence selectivity through induced-fit tight binding interactions within the mycobacterial but not human enzyme, as indicated by kinetic analysis and crystallography.

COVID-19 Clinical Phenotypes: Presentation and Temporal Progression of Disease in a Cohort of Hospitalized Adults in Georgia, United States

BACKGROUND

The epidemiological features and outcomes of hospitalized adults with coronavirus disease 2019 (COVID-19) have been described; however, the temporal progression and medical complications of disease among hospitalized patients require further study. Detailed descriptions of the natural history of COVID-19 among hospitalized patients are paramount to optimize health care resource utilization, and the detection of different clinical phenotypes may allow tailored clinical management strategies.

METHODS

This was a retrospective cohort study of 305 adult patients hospitalized with COVID-19 in 8 academic and community hospitals. Patient characteristics included demographics, comorbidities, medication use, medical complications, intensive care utilization, and longitudinal vital sign and laboratory test values. We examined laboratory and vital sign trends by mortality status and length of stay. To identify clinical phenotypes, we calculated Gower's dissimilarity matrix between each patient's clinical characteristics and clustered similar patients using the partitioning around medoids algorithm.

RESULTS

One phenotype of 6 identified was characterized by high mortality (49%), older age, male sex, elevated inflammatory markers, high prevalence of cardiovascular disease, and shock. Patients with this severe phenotype had significantly elevated peak C-reactive protein creatinine, D-dimer, and white blood cell count and lower minimum lymphocyte count compared with other phenotypes (P < .01, all comparisons).

CONCLUSIONS

Among a cohort of hospitalized adults, we identified a severe phenotype of COVID-19 based on the characteristics of its clinical course and poor prognosis. These findings need to be validated in other cohorts, as improved understanding of clinical phenotypes and risk factors for their development could help inform prognosis and tailored clinical management for COVID-19.

Caught in the Act: Variation in plastid genome inverted repeat expansion within and between populations of Medicago minima

The inverted repeat (IR) lacking clade (IRLC) is a monophyletic group within the Papilionoideae subfamily of Fabaceae where plastid genomes (plastomes) do not contain the large IR typical of land plants. Recently, an IRLC legume, Medicago minima, was found to have regrown a ~9 kb IR that contained a number of canonical IR genes, and closely related M. lupulina contained an incomplete IR of ~425 bp. Complete plastomes were generated for seven additional species, putative members of the M. minima clade. Polymerase chain reaction was employed to investigate the presence of the IR across M. minima and M. lupulina including individuals of nine and eight Eurasian and North African accessions and 15 and 14 Texas populations, respectively. While no sequence similar to the ~9 kb IR was detected among the seven newly sequenced plastomes, all Eurasian and North African accessions of M. minima contained the IR. Variation in IR extent was detected within and between the Texas populations. Expansions of 13 bp and 11 bp occurred at the boundaries of both IR/small single-copy regions, and populations had one or the other expansion, but not both. Expansion of the IR was not detected in the accessions from Eurasia and North Africa suggesting recent mutations yielded at least two additional plastid haplotypes in M. minima.

Predictors at admission of mechanical ventilation and death in an observational cohort of adults hospitalized with COVID-19

Background

Coronavirus disease (COVID-19) can cause severe illness and death. Predictors of poor outcome collected on hospital admission may inform clinical and public health decisions.

Methods

We conducted a retrospective observational cohort investigation of 297 adults admitted to eight academic and community hospitals in Georgia, United States, during March 2020. Using standardized medical record abstraction, we collected data on predictors including admission demographics, underlying medical conditions, outpatient antihypertensive medications, recorded symptoms, vital signs, radiographic findings, and laboratory values. We used random forest models to calculate adjusted odds ratios (aORs) and 95% confidence intervals (CI) for predictors of invasive mechanical ventilation (IMV) and death.

Results

Compared with age <45 years, ages 65–74 years and ≥75 years were predictors of IMV (aOR 3.12, CI 1.47–6.60; aOR 2.79, CI 1.23–6.33) and the strongest predictors for death (aOR 12.92, CI 3.26–51.25; aOR 18.06, CI 4.43–73.63). Comorbidities associated with death (aORs from 2.4 to 3.8, p <0.05) included end-stage renal disease, coronary artery disease, and neurologic disorders, but not pulmonary disease, immunocompromise, or hypertension. Pre-hospital use vs. non-use of angiotensin receptor blockers (aOR 2.02, CI 1.03–3.96) and dihydropyridine calcium channel blockers (aOR 1.91, CI 1.03–3.55) were associated with death.

Conclusions

After adjustment for patient and clinical characteristics, older age was the strongest predictor of death, exceeding comorbidities, abnormal vital signs, and laboratory test abnormalities. That coronary artery disease, but not chronic lung disease, was associated with death among hospitalized patients warrants further investigation, as do associations between certain antihypertensive medications and death.

High Treatment Uptake in Human Immunodeficiency Virus/Hepatitis C Virus-Coinfected Patients After Unrestricted Access to Direct-Acting Antivirals in the Netherlands

Background

The Netherlands has provided unrestricted access to direct-acting antivirals (DAAs) since November 2015. We analyzed the nationwide hepatitis C virus (HCV) treatment uptake among patients coinfected with human immunodeficiency virus (HIV) and HCV.

Methods

Data were obtained from the ATHENA HIV observational cohort in which >98% of HIV-infected patients ever registered since 1998 are included. Patients were included if they ever had 1 positive HCV RNA result, did not have spontaneous clearance, and were known to still be in care. Treatment uptake and outcome were assessed. When patients were treated more than once, data were included from only the most recent treatment episode. Data were updated until February 2017. In addition, each treatment center was queried in April 2017 for a data update on DAA treatment and achieved sustained virological response.

Results

Of 23574 HIV-infected patients ever linked to care, 1471 HCV-coinfected patients (69% men who have sex with men, 15% persons who [formerly] injected drugs, and 15% with another HIV transmission route) fulfilled the inclusion criteria. Of these, 87% (1284 of 1471) had ever initiated HCV treatment between 2000 and 2017, 76% (1124 of 1471) had their HCV infection cured; DAA treatment results were pending in 6% (92 of 1471). Among men who have sex with men, 83% (844 of 1022) had their HCV infection cured, and DAA treatment results were pending in 6% (66 of 1022). Overall, 187 patients had never initiated treatment, DAAs had failed in 14, and a pegylated interferon-alfa-based regimen had failed in 54.

Conclusions

Fifteen months after unrestricted DAA availability the majority of HIV/HCV-coinfected patients in the Netherlands have their HCV infection cured (76%) or are awaiting DAA treatment results (6%). This rapid treatment scale-up may contribute to future HCV elimination among these patients.

Global longitudinal strain to predict left ventricular dysfunction in asymptomatic patients with severe mitral valve regurgitation: literature review

The optimal treatment strategy for asymptomatic patients with severe mitral valve regurgitation (MR) and preserved left ventricular (LV) function is challenging. This manuscript reviews the available literature on the value of left ventricular global longitudinal strain (LV-GLS) in predicting LV dysfunction after mitral valve surgery in these patients and discusses its current place in the treatment strategy. Studies were identified from Cochrane Library, SCOPUS, PubMed and Web of Science up to February 2018. The domain used was MR. The determinant was LV-GLS; other methods of deformation imaging were excluded. The examined outcome was LV dysfunction after surgery. A total of 144 articles were retrieved, of which 11 publications met the inclusion criteria, including a total of 2415 patients. Ten studies showed a significant correlation between preoperative LV-GLS and LV dysfunction postoperatively; one study reported a negative correlation. These studies suggest that LV-GLS is a predictor of LV dysfunction after surgery in asymptomatic patients with chronic MR. Hence, incorporation of LV-GLS for clinical decision-making in these patients might be of additional value. Further research is needed to confirm the role of LV-GLS in postoperative patients, and additionally in asymptomatic MR patients during a ‘watchful waiting’ strategy.

Lost and Found: Return of the Inverted Repeat in the Legume Clade Defined by Its Absence

The plant genome comprises a coevolving, integrated genetic system housed in three subcellular compartments: the nucleus, mitochondrion, and the plastid. The typical land plant plastid genome (plastome) comprises the sum of repeating units of 130–160 kb in length. The plastome inverted repeat (IR) divides each plastome monomer into large and small single copy regions, an architecture highly conserved across land plants. There have been varying degrees of expansion or contraction of the IR, and in a few distinct lineages, including the IR-lacking clade of papilionoid legumes, one copy of the IR has been lost. Completion of plastome sequencing and assembly for 19 Medicago species and Trigonella foenum-graceum and comparative analysis with other IR-lacking clade taxa revealed modest divergence with regard to structural organization overall. However, one clade contained unique variation suggesting an ancestor had experienced repeat-mediated changes in plastome structure. In Medicago minima, a novel IR of ∼9 kb was confirmed and the role of repeat-mediated, recombination-dependent replication in IR reemergence is discussed.

Feasibility of a quantitative polymerase chain reaction assay for diagnosing pneumococcal pneumonia using oropharyngeal swabs

Streptococcus pneumoniae is the most important pathogen causing community-acquired pneumonia (CAP). The current diagnostic microbial standard detects S. pneumoniae in less than 30% of CAP cases. A quantitative polymerase chain reaction (PCR) targeting autolysin (lytA) is able to increase the rate of detection. The aim of this study is validation of this quantitative PCR in vitro using different available strains and in vivo using clinical samples (oropharyngeal swabs). The PCR autolysin (lytA) was validated by testing the intra- and inter-run variability. Also, the in vitro specificity and sensitivity, including the lower limit of detection was determined. In addition, a pilot-study was performed using samples from patients (n = 28) with pneumococcal pneumonia and patients (n = 28) with a pneumonia without detection of S. pneumoniae with the current diagnostic microbial standard, but with detection of either a viral and or another bacterial pathogen to validate this test further. The intra- and inter-run variability were relatively low (SD's ranging from 0.08 to 0.96 cycle thresholds). The lower limit of detection turned out to be 1-10 DNA copies/reaction. In-vitro sensitivity and specificity of the tested specimens (8 strains carrying lytA and 6 strains negative for lytA) were both 100%. In patients with pneumococcal and non-pneumococcal pneumonia a cut-off value of 6.000 copies/mL would lead to a sensitivity of 57.1% and a specificity of 85.7%. We were able to develop a quantitative PCR targeting lytA with good in-vitro test characteristics.

Longitudinal echocardiographic and clinical follow-up of patients undergoing mitral valve surgery without concomitant tricuspid valve repair

Background

In patients with mild to moderate functional tricuspid regurgitation (TR) and absence of right ventricular dysfunction or tricuspid annulus (TA) dilatation, there is currently no indication for concomitant tricuspid valve (TV) repair during elective mitral valve (MV) surgery. However, long-term results are conflicting. Here, we sought to determine the clinical outcome of this cohort, the rate of TR progression after MV surgery and the role of MV aetiology.

Methods

Patients for elective MV surgery without concomitant TV repair were retrospectively analysed with longitudinal echocardiographic and clinical follow-up, focusing on TR progression and MV aetiology. Linear regression analysis was performed for change in TR at follow-up, using pre-determined variables and confounders.

Results

In total 204 patients without TV repair were analysed. Development of more than moderate TR after a median of 3.1 [1.6–4.6] years was rarely seen: only in 2 out of 161 patients (1.2%) with known TR grade at follow-up. Overall, median preoperative and late postoperative TR grade were equal (p = 0.116). Subanalysis showed no significant difference in MV aetiology subgroups. Preoperative TR grade and male gender were inversely correlated to change in TR. Mortality was not influenced by the 1‑year postoperative TR severity.

Conclusion

Our data showed that in a study population of patients with mild to moderate TR undergoing MV surgery without concomitant TV repair, significant late TR was rarely seen. Based on our study, it is safe to waive concomitant TV repair in this specific patient cohort.

Electronic supplementary material

The online version of this article (10.1007/s12471-018-1159-4) contains supplementary material, which is available to authorized users.

Evaluation of mitral regurgitation by an integrated 2D echocardiographic approach in patients undergoing transcatheter aortic valve replacement

The purpose of this study was to evaluate mitral regurgitation (MR) severity in patients undergoing transcatheter aortic valve replacement (TAVR) by standardized assessment of two-dimensional (2D) transthoracic echocardiography (TTE) and 1-year echocardiographic and clinical outcomes. Pre- and post-procedural TTE's of patients undergoing TAVR between 2008 and 2014 were analyzed. MR was graded according to current guidelines with a systematic and integrated approach. Longitudinal echocardiographic and clinical results were analyzed. Regression analysis was performed for change in MR grade at follow-up, using pre-determined variables and confounders. Pre- and post-procedural TTE were available in 213 subjects. Significant MR was seen in 22% at baseline and 15% at follow-up; MR grade ≥ 3 in < 10%. Severity did not change in 61%, and decreased in 20% of the patients. Overall, the prevalence of MR grades pre- and post TAVR was not significantly different, nor influenced by MR etiology or TAVR prosthesis type. However, higher MR grades and pacemaker absence at baseline, were independently correlated to more improvement of MR after TAVR. Regarding clinical outcomes, NYHA class improved in two-thirds of the patients, irrespective of the baseline MR grade. Overall survival was not significantly different amongst MR grades post-TAVR. MR grading using an systematic 2D echocardiographic approach in patients undergoing TAVR is feasible in clinical practice. Our data revealed a relatively frequent prevalence of significant MR (although grade ≥ 3 was scarce), overall no change in the MR grade at 1 year follow-up, improvement of functional NYHA class, and no significant differences in long-term survival amongst the post-TAVR MR grades.

Metastatic Crohn disease: a review of dermatologic manifestations and treatment

It is estimated that almost half of patients affected with Crohn disease (CD) experience a dermatologic manifestation of the condition. Metastatic CD (MCD) is a rare dermatologic entity, with as few as 100 cases reported in the literature. As such, MCD presents a clinical dilemma in diagnosis and management. The etiology of MCD is not well defined; however, prevailing theories agree that the underlying mechanism is an immunologic response to gut antigens. Diagnosis requires a high index of suspicion and usually is made by exclusion of other processes. Treatment success has been reported with the use of antibiotics, immunosuppressants, and sometimes surgical treatment. We review the etiology/epidemiology, diagnostic criteria, and treatment of this uncommon condition.

Fumarase Deficiency Causes Protein and Metabolite Succination and Intoxicates Mycobacterium tuberculosis

Enzymes of central carbon metabolism are essential mediators of Mycobacterium tuberculosis (Mtb) physiology and pathogenicity, but are often perceived to lack sufficient species selectivity to be pursued as potential drug targets. Fumarase (Fum) is an enzyme of the canonical tricarboxylic acid cycle and is dispensable in many organisms. Transposon mutagenesis studies in Mtb, however, indicate that Fum is required for optimal growth. Here, we report the generation and characterization of a genetically engineered Mtb strain in which Fum expression is conditionally regulated. This revealed that Fum deficiency is bactericidal in vitro and during both the acute and chronic phases of mouse infection. This essentiality is linked to marked accumulations of fumarate resulting in protein and metabolite succination, a covalent modification of cysteine thiol residues. These results identify Mtb Fum as a potentially species-specific drug target whose inactivation may kill Mtb through a covalently irreversible form of metabolic toxicity.

Three New Potent HIV-1 Inhibitors from Myxobacteria

Three novel compounds, namely, phenoxan, phenalamide A1, and thiangazole, were found to suppress HIV-1 replication in cell cultures. The compounds were discovered by screening crude extracts from myxobacteria and were isolated from two strains of Polyangium sp. and a strain of Myxococcus stipitatus. Their structures have been elucidated. The cytotoxic concentrations for MT-4 cells were 6.6 μM for phenoxan, 102 μM for phenalamide A1, and 4.7 μM for thiangazole. Phenoxan inhibited the HIV-1-dependent cell death at concentrations of as low as 6.6 nM. Phenalamide A1 could prevent the HIV-1 infection of MT-4 cells even at concentrations of 1.02nM, and thiangazole at 4.7 pM. In our assay thiangazole is at least 100 times more active than AZT. The compounds could not prevent syncythia formation induced by HIV-1. However, like HEPT (Baba et al., 1989; Miyasaka et al., 1989) and TIBO (Pauwels et al., 1990) derivatives they are highly specific since they could not interfere with HIV-2ben dependent MT-4 cell death. HIV-1 RT activity was inhibited by 50% by 376 μM phenoxan, 386 μM phenalamid A1, or 263 μM thiangazole. Since these concentrations are approximately 50000 times higher than their minimum concentrations active in cell cultures, RT-inhibition does not appear to be the major mechanism of HIV-inhibition of the new agents.

Gene expression in major depressive disorder

The search for genetic variants underlying major depressive disorder (MDD) has not yet provided firm leads to its underlying molecular biology. A complementary approach is to study gene expression in relation to MDD. We measured gene expression in peripheral blood from 1848 subjects from The Netherlands Study of Depression and Anxiety. Subjects were divided into current MDD (N=882), remitted MDD (N=635) and control (N=331) groups. MDD status and gene expression were measured again 2 years later in 414 subjects. The strongest gene expression differences were between the current MDD and control groups (129 genes at false-discovery rate, FDR<0.1). Gene expression differences across MDD status were largely unrelated to antidepressant use, inflammatory status and blood cell counts. Genes associated with MDD were enriched for interleukin-6 (IL-6)-signaling and natural killer (NK) cell pathways. We identified 13 gene expression clusters with specific clusters enriched for genes involved in NK cell activation (downregulated in current MDD, FDR=5.8 × 10(-5)) and IL-6 pathways (upregulated in current MDD, FDR=3.2 × 10(-3)). Longitudinal analyses largely confirmed results observed in the cross-sectional data. Comparisons of gene expression results to the Psychiatric Genomics Consortium (PGC) MDD genome-wide association study results revealed overlap with DVL3. In conclusion, multiple gene expression associations with MDD were identified and suggest a measurable impact of current MDD state on gene expression. Identified genes and gene clusters are enriched with immune pathways previously associated with the etiology of MDD, in line with the immune suppression and immune activation hypothesis of MDD.

Gene transcripts associated with muscle strength: a CHARGE meta-analysis of 7,781 persons

Lower muscle strength in midlife predicts disability and mortality in later life. Blood-borne factors, including growth differentiation factor 11 (GDF11), have been linked to muscle regeneration in animal models. We aimed to identify gene transcripts associated with muscle strength in adults. Meta-analysis of whole blood gene expression (overall 17,534 unique genes measured by microarray) and hand-grip strength in four independent cohorts (n = 7,781, ages: 20-104 yr, weighted mean = 56), adjusted for age, sex, height, weight, and leukocyte subtypes. Separate analyses were performed in subsets (older/younger than 60, men/women). Expression levels of 221 genes were associated with strength after adjustment for cofactors and for multiple statistical testing, including ALAS2 (rate-limiting enzyme in heme synthesis), PRF1 (perforin, a cytotoxic protein associated with inflammation), IGF1R, and IGF2BP2 (both insulin like growth factor related). We identified statistical enrichment for hemoglobin biosynthesis, innate immune activation, and the stress response. Ten genes were associated only in younger individuals, four in men only and one in women only. For example, PIK3R2 (a negative regulator of PI3K/AKT growth pathway) was negatively associated with muscle strength in younger (<60 yr) individuals but not older (≥ 60 yr). We also show that 115 genes (52%) have not previously been linked to muscle in NCBI PubMed abstracts. This first large-scale transcriptome study of muscle strength in human adults confirmed associations with known pathways and provides new evidence for over half of the genes identified. There may be age- and sex-specific gene expression signatures in blood for muscle strength.

Serum proteomic profiling of major depressive disorder

Much has still to be learned about the molecular mechanisms of depression. This study aims to gain insight into contributing mechanisms by identifying serum proteins related to major depressive disorder (MDD) in a large psychiatric cohort study. Our sample consisted of 1589 participants of the Netherlands Study of Depression and Anxiety, comprising 687 individuals with current MDD (cMDD), 482 individuals with remitted MDD (rMDD) and 420 controls. We studied the relationship between MDD status and the levels of 171 serum proteins detected on a multi-analyte profiling platform using adjusted linear regression models. Pooled analyses of two independent validation cohorts (totaling 78 MDD cases and 156 controls) was carried out to validate our top markers. Twenty-eight analytes differed significantly between cMDD cases and controls (P < 0.05), whereas 10 partly overlapping markers differed significantly between rMDD cases and controls. Antidepressant medication use and comorbid anxiety status did not substantially impact on these findings. Sixteen of the cMDD-related markers had been assayed in the pooled validation cohorts, of which seven were associated with MDD. The analytes prominently associated with cMDD related to diverse cell communication and signal transduction processes (pancreatic polypeptide, macrophage migration inhibitory factor, ENRAGE, interleukin-1 receptor antagonist and tenascin-C), immune response (growth-regulated alpha protein) and protein metabolism (von Willebrand factor). Several proteins were implicated in depression. Changes were more prominent in cMDD, suggesting that molecular alterations in serum are associated with acute depression symptomatology. These findings may help to establish serum-based biomarkers of depression and could improve our understanding of its pathophysiology.

Review article: the safety of therapeutic drugs in male inflammatory bowel disease patients wishing to conceive

BACKGROUND

Many therapeutic drugs are used by patients with inflammatory bowel disease, often around the time of conception. The pregnancy outcomes of males and females exposed to these therapeutics needs to be examined and this information is necessary to counsel patients appropriately.

AIM

To review the literature describing male infertility and inflammatory bowel disease to educate practitioners of the impact of inflammatory bowel disease on male reproduction and the impact of therapeutics on pregnancy outcomes.

METHODS

We performed a PubMed search using the search terms 'male infertility,' 'Crohn's disease,' 'inflammatory bowel disease,' 'ulcerative colitis,' 'ciprofloxacin AND infertility,' 'metronidazole AND infertility,' 'sulfasalazine AND infertility,' 'azathioprine AND infertility,' 'methotrexate AND infertility,' 'ciclosporin AND infertility,' 'corticosteroids AND infertility,' 'infliximab AND male fertility,' 'infliximab AND infertility,' 'infliximab AND foetus,' 'infliximab AND paternal exposure' and 'infliximab AND sperm.' References from selected papers were reviewed and used if relevant.

RESULTS

Over half of male patients with IBD have some degree of infertility, compared to 8-17% of the general population. Semen parameters including total count, motility and morphology may be adversely affected by therapeutics. IBD medications in males do not increase foetal risk with the possible exception of azathioprine and mercaptopurine; however, increased foetal risk is seen in other drugs if taken by female patients.

CONCLUSIONS

It is recognised that male infertility is often impacted with therapeutic drugs used to treat inflammatory bowel disease; however, the effects of the paternal drug exposure at the time of conception and exposure in utero should be considered to counsel patients appropriately.

Longitudinal weight differences, gene expression and blood biomarkers in BMI-discordant identical twins

Background

BMI discordant monozygotic (MZ) twins allows an examination of the causes and consequences of adiposity in a genetically controlled design. Few studies have examined longitudinal BMI discordance in MZ pairs.

Objectives

To study the development over time of BMI discordance in adolescent and adult MZ twin pairs, and to examine lifestyle, metabolic, inflammatory, and gene expression differences associated with concurrent and long-term BMI discordance in MZ pairs.

Subjects/Methods

BMI data from 2775 MZ twin pairs, collected in eight longitudinal surveys and a biobank project between 1991 and 2011, were analyzed to characterize longitudinal discordance. Lifestyle characteristics were compared within discordant pairs (ΔBMI ≥ 3 kg/m²) and biomarkers (lipids, glucose, insulin, CRP, fibrinogen, IL-6, TNF-α and sIL-6R and liver enzymes AST, ALT and GGT) and gene expression were compared in peripheral blood from discordant pairs who participated in the NTR biobank project.

Results

The prevalence of discordance ranged from 3.2% in 1991 (mean age=17, SD=2.4) to 17.4% (N=202 pairs) in 2009 (mean age=35, SD=15), and was 16.5% (N=174) among pairs participating in the biobank project (mean age=35, SD=12). Of 699 MZ with BMI data from 3-5 time points, 17 pairs (2.4%) were long-term discordant (at all available time points; mean follow-up range=6.4 years). Concurrently discordant pairs showed significant differences in self-ratings of which twin eats most (p=2.3×10⁻¹³), but not in leisure time exercise activity (p=0.28) and smoking (p>0.05). Ten out of 14 biomarkers showed significantly more unfavorable levels in the heavier of twin of the discordant pairs (p-values < 0.001); most of these biomarker differences were largest in longitudinally discordant pairs. No significant gene expression differences were identified, although high ranking genes were enriched for Gene Ontology (GO) terms highlighting metabolic gene regulation and inflammation pathways.

Conclusions

BMI discordance is uncommon in adolescent identical pairs but increases with higher pair-mean of BMI at older ages, although long-term BMI discordance is rare. In discordant pairs, the heavier twin had a more unfavorable blood biomarker profile than the genetically matched leaner twin, in support of causal effects of obesity.

Psychiatric nursing: an unpopular choice

Research studies in the United States, the United Kingdom, New Zealand and Australia suggest that students do not consider psychiatric nursing as a popular career option. According to this research, there is a widespread concern about the nursing shortages in psychiatry. The demand for mental health services continues to grow and there is a need for strategies to recruit nurses for this specialized field. The purpose of this study was to identify the factors preventing undergraduate nursing students in South Africa (SA) from choosing psychiatric nursing as a career. A qualitative research design that aimed to explore and describe was used. Data were collected through the Nominal Group Technique. A sample of convenience of 27 final year nursing students from the School of Nursing at the University of the Free State as well as the Free State School of Nursing, situated in Bloemfontein (SA), voluntarily participated in this research. The following categories emerged from the content analysis of the data: personal factors, working environment, unprofessional behaviour, learning environment and the unclassified category. Psychiatric nursing as a career choice is in a predicament and nursing schools need to implement practical strategies to recruit future nurses for this field.

Synthesis of new carolacton derivatives and their activity against biofilms of oral bacteria

Carolacton, a secondary metabolite isolated from the extracts ofSorangium cellulosum, causes membrane damage and cell death in biofilms of different oral bacteria.

Evolutionary and biotechnology implications of plastid genome variation in the inverted-repeat-lacking clade of legumes

Land plant plastid genomes (plastomes) provide a tractable model for evolutionary study in that they are relatively compact and gene dense. Among the groups that display an appropriate level of variation for structural features, the inverted-repeat-lacking clade (IRLC) of papilionoid legumes presents the potential to advance general understanding of the mechanisms of genomic evolution. Here, are presented six complete plastome sequences from economically important species of the IRLC, a lineage previously represented by only five completed plastomes. A number of characters are compared across the IRLC including gene retention and divergence, synteny, repeat structure and functional gene transfer to the nucleus. The loss of clpP intron 2 was identified in one newly sequenced member of IRLC, Glycyrrhiza glabra. Using deeply sequenced nuclear transcriptomes from two species helped clarify the nature of the functional transfer of accD to the nucleus in Trifolium, which likely occurred in the lineage leading to subgenus Trifolium. Legumes are second only to cereal crops in agricultural importance based on area harvested and total production. Genetic improvement via plastid transformation of IRLC crop species is an appealing proposition. Comparative analyses of intergenic spacer regions emphasize the need for complete genome sequences for developing transformation vectors for plastid genetic engineering of legume crops.

Perirenal extra-adrenal myelolipoma

Myelolipomas are rare tumors consisting of both adipose and hematopoietic tissue and are typically found within the adrenal gland. Extra-adrenal involvement is rare, especially those tumors involving the perirenal space and collecting system. We report a case of a patient with an incidentally discovered perirenal mass that was initially concerning for a retroperitoneal liposarcoma. Following surgical resection and pathological analysis, the lesion was found to be an extra-adrenal myelolipoma. This case report and review of the literature demonstrates the importance of the proper work-up and management of perirenal lipoma variants while addressing the issues of tissue biopsy, surgical intervention, and pre- and post-operative surveillance.

Vibrio vulnificus outbreaks in Dutch eel farms since 1996: strain diversity and impact

Vibrio vulnificus is a potentially zoonotic bacterial pathogen of fish, which can infect humans (causing necrotic fasciitis). We analysed 24 V. vulnificus isolates (from 23 severe eel disease outbreaks in 8 Dutch eel farms during 1996 to 2009, and 1 clinical strain from an eel farmer) for genetic correlation and zoonotic potential. Strains were typed using biotyping and molecular typing by high-throughput multilocus sequence typing (hiMLST) and REP-PCR (Diversilab®). We identified 19 strains of biotype 1 and 5 of biotype 2 (4 from eels, 1 from the eel farmer), that were subdivided into 8 MLST types (ST) according to the international standard method. This is the first report of V. vulnificus biotype 1 outbreaks in Dutch eel farms. Seven of the 8 STs, of unknown zoonotic potential, were newly identified and were deposited in the MLST database. The REP-PCR and the MLST were highly concordant, indicating that the REP-PCR is a useful alternative for MLST. The strains isolated from the farmer and his eels were ST 112, a known potential zoonotic strain. Antimicrobial resistance to cefoxitin was found in most of the V. vulnificus strains, and an increasing resistance to quinolones, trimethoprim + sulphonamide and tetracycline was found over time in strain ST 140. Virulence testing of isolates from diseased eels is recommended, and medical practitioners should be informed about the potential risk of zoonotic infections by V. vulnificus from eels for the prevention of infection especially among high-risk individuals. Additional use of molecular typing methods such as hiMLST and Diversilab® is recommended for epidemiological purposes during V. vulnificus outbreaks.

A review of urinary fistulae in Crohn's disease

INTRODUCTION

Urinary fistulae develop as abnormal connections between the gastrointestinal (GI) and genitourinary (GU) tracts, and occur in multiple disease processes including diverticulitis, malignancy, and Crohn's disease. Crohn's disease is now the most common cause of fistula formation between the ileum and bladder and the third most common cause of fistulae between the colon and the bladder. Few articles provide a comprehensive review of this process.

MATERIALS AND METHODS

We performed a PubMed search using such terms as "fistula" and "Crohn's disease" and/or "enterovesical fistula." We reviewed references from selected papers and relevant articles were used for information-gathering and cited accordingly.

RESULTS

Fistulae in Crohn's disease generally occur due to preformed abscess formation or bowel perforation from the development of aphthous ulcers. The most common type of urinary fistula is enterovesical, due to the close proximity of the ileum and bladder dome. Computed tomography and cystoscopy are the most common diagnostic tools utilized. Surgical treatment is usually definitive; however medical treatment has been used with some success as well.

CONCLUSION

Urinary fistulae represent an uncommon, yet serious problem to patients with Crohn's disease. Patient symptoms and imaging direct the practitioner to proper diagnosis, with direct visualization via cystoscopy confirming the presence of a urinary fistula. Treatment is aimed at relieving symptoms and may be medical or surgical depending on the clinical presentation.

Spin heat accumulation induced by tunneling from a ferromagnet

An electric current from a ferromagnet into a nonmagnetic material can induce a spin-dependent electron temperature. Here, it is shown that this spin heat accumulation, when created by tunneling from a ferromagnet, produces a non-negligible voltage signal that is comparable to that due to the coexisting electrical spin accumulation and can give a different Hanle spin precession signature. The effect is governed by the spin polarization of the Peltier coefficient of the tunnel contact, its Seebeck coefficient, and the spin heat resistance of the nonmagnetic material, which is related to the electrical spin resistance by a spin-Wiedemann-Franz law. Moreover, spin heat injection is subject to a heat conductivity mismatch that is overcome if the tunnel interface has a sufficiently large resistance.

Further confirmation of the association between anxiety and CTNND2: replication in humans

The rat genome sequencing and mapping consortium found evidence for an association between the catenin-δ2 gene (CTNND2) and anxious behaviour. We replicated these results in humans by carrying out a genetic association test in patients with panic disorder, social phobia, generalized anxiety disorder and/or agoraphobia (N = 1714) and controls (N = 4125). We further explored the association between CTNND2 and other psychiatric disorders based on publicly available genome-wide association results. A gene-based test showed that single nucleotide polymorphisms (SNPs) in CTNND2 have a significantly increased signal (P < 1e(-5) ) and decreased P-values. Single nucleotide polymorphism rs1012176 showed the strongest association with any anxiety disorder (odds ratio: 0.8128, SE = 0.063, P = 0.00099), but this effect was not significant after correction for multiple testing. In available genome-wide association results from the Psychiatric Genomics Consortium we found that SNPs in CTNND2 collectively showed an increased signal for schizophrenia (P < 1e(-5) ) and major depressive disorder (P < 1e(-5) ), but not for bipolar disorder. These signals remained significant after correction for potential confounders. The association between CTNND2 and anxiety was not strong enough to be picked up in the current generation of human genome-wide analyses, indicating the usefulness of and need for animal genetic studies to identify candidate genes for further study in human samples.

Identification of Haemophilus influenzae and Haemophilus haemolyticus by matrix-assisted laser desorption ionization-time of flight mass spectrometry

Generally accepted laboratory methods that have been used for decades do not reliably distinguish between H. influenzae and H. haemolyticus isolates. H. haemolyticus strains are often incorrectly identified as nontypeable Haemophilus influenzae (NTHi). To distinguish H. influenzae from H. haemolyticus we have created a new database on the matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) bio-typer 2 and compared the results with routine determination of Haemophilus (growth requirement for X and V factor), and multilocus sequence typing (MLST). In total we have tested 277 isolates, 244 H. influenzae and 33 H. haemolyticus. Using MLST as the gold standard, the agreement of MALDI-TOF MS was 99.6 %. MALDI-TOF MS allows reliable and rapid discrimination between H. influenzae and H. haemolyticus.

An atypical presentation of testicular torsion: a case report

Testicular torsion is an emergent condition requiring prompt surgical intervention to avoid permanent testicular compromise and death. As its symptoms overlap with other disease processes, diagnosis is sometimes difficult. When considering the presenting symptoms, one must be careful not to ignore unusual causes of torsion and misdiagnose the patient. In this case report we describe an unusual etiology of testicular torsion (traumatic) with an atypical patient presentation (mildly painful) which presented many obstacles before proper diagnosis and treatment.

The role of exercise echocardiography in the management of mitral valve disease

PURPOSE

Exercise echocardiography can assess the dynamic component of mitral valve (MV) disease and may therefore be helpful for the clinical decision-making by the heart team. The purpose of this study is to determine the role of exercise echocardiography in the management of disproportionately symptomatic or otherwise atypical patients with mitral regurgitation (MR) and stenosis (MS) in clinical practice.

METHODS

Data of 14 MR and 14 MS patients, including echocardiograms at rest, were presented retrospectively to an experienced heart team to determine treatment strategy. Subsequently, exercise echo data were provided whereupon once again the treatment strategy was determined. This resulted in: value of exercise echo by means of 1) alteration or 2) confirmation of treatment strategy or 3) no additional value.

RESULTS

During exercise the echocardiographic severity of MV disease increased in 9 (64 %) MR and 8 (57 %) MS patients. Based upon alteration or confirmation of the treatment strategy, the value of exercise echocardiography in the management of MR and MS was 86 % and 57 %, respectively.

CONCLUSION

This study showed that physical exercise echo can have an important role in the clinical decision-making of challenging patients with MV disease. Exercise echocardiography had additional value to the treatment strategy in 71 % of these patients.