National trends in the initial diagnosis and management of carpal tunnel syndrome: results from the ELECTS (ELEctrophysiology in Carpal Tunnel Syndrome) study

INTRODUCTION

The optimal role of nerve conduction studies (NCS) in management of carpal tunnel syndrome (CTS) is unclear, with no standardised guidance. This study aimed to identify variation in practice in the initial diagnosis of patients with suspected CTS, alongside evaluating how NCS findings influence clinical decision making.

METHODS

A national multicentre collaborative survey was conducted in 2021. All centres providing surgery for CTS were invited to participate, primarily via social media. All middle-senior grade orthopaedic/plastic surgeons and advanced care practitioners that regularly manage new referrals for suspected CTS were eligible to respond. Local representatives at each participating site submitted their responses to a central team who collated and analysed the results.

RESULTS

A total of 137 healthcare professionals responded from 18 UK NHS Trusts. Of these 137, 124 (91%) reported not employing any validated clinical questionnaires in their routine practice, preferring to rely on clinical diagnosis and/or NCS if available, whereas 84 (61%) utilised NCS to aid diagnosis, with significant differences among professionals with differing experience (p < 0.01). The most common methods for determining the severity of CTS were history, examination and NCS. In symptomatic CTS with confirmatory NCS, over 50% of clinicians would choose surgical decompression as their first-line intervention. In cases of either negative NCS or atypical presentation, 37% and 51%, respectively, would consider conservative management (e.g. splintage) or steroid injection first line.

CONCLUSIONS

With growing waiting lists for NCS and surgery, national consensus guidelines should be developed to support decision making, while maximising efficient utilisation of increasingly constrained resources.

Radiological Criteria for Acceptable Alignment in Paediatric Mid-Shaft Forearm Fractures: A Systematic Review

Introduction

Forearm fractures are common in children. The remodelling capacity of growing long bones in children makes these potentially forgiving injuries, recovering with good outcomes despite minimal intervention. Clinicians rely on radiological characteristics that vary with age to guide treatment decisions and minimise adverse sequelae. The purpose of this review was to consolidate the evidence base of radiological indications for intervention in paediatric mid-shaft forearm fractures.

Materials and methods

The preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines were followed for this review. Citable research output reporting radiological criteria for mid-shaft forearm fractures in paediatric patients (age ≤16 years) was screened and analysed to ascertain acceptable radiological criteria for non-operative management.

Results

A total of 2,059 papers were initially identified; 14 were selected following screening. Sagittal angulation >15°, coronal angulation >10°, and/or >50% (or >1cm) translation were the most common radiological indications for intervention in children aged 0 to 10 years. For children over 10 years of age, the most common radiological indication for intervention was sagittal angulation >10°, coronal angulation >10°, and/or >50% (or >1cm) translation.

Conclusion

This study revealed a scarcity of high-quality evidence to guide management and significant variation in outcome reporting throughout the published literature. Since Noonan and Price's 1998 recommendations, there has been no significant evolution in the evidence-base guided threshold for intervention in paediatric mid-shaft forearm fractures. There remains a pressing need for a robust multicentre observational study using the patient-reported outcome measurement information system (PROMIS) to address this complex and controversial area of uncertainty in paediatric trauma management.

Wavelet coherence phase analysis decodes the universal switching mechanism of Ras GTPase superfamily

The Ras superfamily of GTPases regulate critical cellular processes by shuttling between GTP-bound ON and GDP-bound OFF states. This switching mechanism is attributed to the conformational changes in two loops, SWI and SWII, upon GTP binding and hydrolysis. Since these conformational changes vary across the Ras superfamily, there is no generic parameter to define their functional states. A unique wavelet coherence (WC) analysis-based approach developed here shows that the structural changes in switch regions could be mapped onto the wavelet coherence phase couplings (WPCs). Thus, WPCs could serve as unique parameters to define their functional states. Disentanglement of WPCs in oncogenic GTPases shows how breakdown of structural allostery leads to their aberrant function. These observations stand out even for simulated ensemble of switch region conformers. Overall, for the first time, we show that WPCs could unravel the latent structural deviations in Ras proteins to decode their universal switching mechanism.

In silico identification and characterization of the SNPs in the human ASTL gene and their probable role in female infertility

Ovastacin (ASTL), a zinc metalloprotease, is released from a fertilized egg during exocytosis of cortical granules which occurs minutes after the sperm and egg fuse. ASTL cleaves ZP2, one of the four primary glycoproteins of human zona pellucida, and this cleavage prevents polyspermy, causes zona pellucida hardening, and also protects the pre-implantation embryo. Any perturbation in the activity of ASTL can thus disturb this process and may lead to infertility without changing the gross morphology of the oocyte. A small amount of ASTL is also released by unfertilized oocytes but its catalytic activity is absent as it is bound by its inhibitor, Fetuin-B (FETUB). Pre-mature release of ASTL when FETUB is absent also causes infertility. To identify and understand the structural and functional effects of deleterious SNPs of ASTL on its interaction with ZP2 and FETUB and hence on fertility, a total of 4,748 SNPs from the dbSNP database were evaluated using a variety of in silico tools. All of the 40 shortlisted nsSNPs were present in the catalytic domain of the protein. Comparison of the wild type with mutants using MutPred2 suggests an alteration in the catalytic activity/zinc binding site in many SNPs. Docking studies show the involvement of hydrophobic interactions and H bonding between ASTL and ZP2 and also between ASTL and FETUB. Four positions in ASTL involved in the hydrophobic interactions (P¹⁰⁵ and D²⁰⁰ between ASTL and ZP2; D¹⁹⁸ and L²⁷⁸ between ASTL and FETUB) and 5 in H bonding (E⁷⁵ and R¹⁵⁹ between ASTL and ZP2; and K⁹³, R^159, and C²⁸¹ between ASTL and FETUB) have SNP's associated with them validating their importance. Interestingly, a cluster of multiple SNPs was found in the motif ¹⁹⁸DRD²⁰⁰, which is also a well-conserved region among several species. Statistical Coupling Analysis (SCA) suggested that the deleterious SNPs were present in the functionally important amino acid positions of ASTL and are evolutionarily coupled. Thus, these results attempt to identify the regions in ASTL, mutations in which can affect its binding with ZP2 or FETUB and cause female infertility.

Evolutionary conservation of protein dynamics: insights from all-atom molecular dynamics simulations of 'peptidase' domain of Spt16

Protein function is encoded in its sequence, manifested in its three-dimensional structure, and facilitated by its dynamics. Studies have suggested that protein structures with higher sequence similarity could have more similar patterns of dynamics. However, such studies of protein dynamics within and across protein families typically rely on coarse-grained models, or approximate metrics like crystallographic B-factors. This study uses µs scale molecular dynamics (MD) simulations to explore the conservation of dynamics among homologs of ∼50 kDa N-terminal module of Spt16 (Spt16N). Spt16N from Saccharomyces cerevisiae (Sc-Spt16N) and three of its homologs with 30-40% sequence identities were available in the PDB. To make our data-set more comprehensive, the crystal structure of an additional homolog (62% sequence identity with Sc-Spt16N) was solved at 1.7 Å resolution. Cumulative MD simulations of 6 µs were carried out on these Spt16N structures and on two additional protein structures with varying degrees of similarity to it. The simulations revealed that correlation in patterns of backbone fluctuations vary linearly with sequence identity. This trend could not be inferred using crystallographic B-factors. Further, normal mode analysis suggested a similar pattern of inter-domain (inter-lobe) motions not only among Spt16N homologs, but also in the M24 peptidase structure. On the other hand, MD simulation results highlighted conserved motions that were found unique for Spt16N protein, this along with electrostatics trends shed light on functional aspects of Spt16N.Communicated by Ramaswamy H. Sarma.

Substrate induced dynamical remodeling of the binding pocket generates GTPase specificity in DOCK family of guanine nucleotide exchange factors

Dedicator of cytokinesis (DOCK) family of guanine nucleotide exchange factors (GEFs) activate two members of Rho family GTPases, Rac1/Cdc42, to exert diverse cellular processes, including cell migration. As DOCK GEFs have been critically implicated in tumour cell migration, understanding their function and specificity is imperative for designing anti-metastatic drugs. Based on their GTPase specificity they have been classified as Rac, Cdc42 and dual specific GEFs. Despite extensive structural studies, the factors that determine GTPase specificity of DOCK GEFs have remained elusive. Here, we show that subtle dynamical coupling between GEF and GTPase structures modulate the binding interface to generate mutual specificity. To cluster the dynamically coupled residues in GEF-GTPase complexes a novel intra-residue backbone-torsion-angles based mutual information (TMI) technique was employed. TMI was calculated from 4500 trajectories obtained from a total of 4.5μs molecular dynamics simulations performed on members of all the three clades of DOCK GEFs. The obtained clusters suggest a specificity generation mechanism that involves optimization of the binding pocket for the crucial divergent residue at the 56^th position of Rac/Cdc42 (FCdc42/WRac1). These clusters encompass five residues from the structural segment lobe C - α10 helix of the DOCK proteins and functional SWI region of GTPase, which induce orchestrated structural modulations to generate the specificity. Even the conserved residues from SWI region are seen to augment the specificity defining dynamical rearrangements. Furthermore, the proposed dynamical GTPase- DOCK GEF specificity model was verified using mutagenesis studies on Rac1 and dual GTPase specific Dock2 and Dock6, respectively. Thus the current study provides the generic substrate specificity determinants of DOCK GEFs, which are not apparent from the conventional structural analysis.

GPCRs that Rhoar the Guanine nucleotide exchange factors

Cell migration, a crucial step in numerous biological processes, is tightly regulated in space and time. Cells employ Rho GTPases, primarily Rho, Rac, and Cdc42, to regulate their motility. Like other small G proteins, Rho GTPases function as biomolecular switches in regulating cell migration by operating between GDP bound 'OFF' and GTP bound 'ON' states. Guanine nucleotide exchange factors (GEFs) catalyse the shuttling of GTPases from OFF to ON state. G protein-coupled receptors (GPCRs) are the largest family of cell surface receptors that are involved in many signalling phenomena including cell survival and cell migration events. In this review, we summarize signalling mechanisms, involving GPCRs, leading to the activation of RhoGEFs. GPCRs exhibit diverse GEF activation modes that include the interaction of heterotrimeric G protein subunits with different domains of GEFs, phosphorylation, protein-protein interaction, protein-lipid interaction, and/or a combination of these processes.

Labrune Syndrome: A Very Rare Association of Leukoencephalopathy, Cerebral Calcifications, and Cysts

Leukoencephalopathy, cerebral calcifications, and cysts (LCC) form a very rare association which is named as “Labrune syndrome” after Labrune who reported the first case in 1996. To the best of our knowledge only eight to 10 cases have been reported in literature to date. We report a case of a 26-year-old male with onset of neurological symptoms in late adolescence (at 19 years of age) and presented with complains of continued seizures for 7 years, giddiness with imbalance, and slowly progressive motor symptoms. MRI brain revealed multiple calcifications in bilateral basal ganglia, cerebral white matter, multiple cystic lesions in the supratentorial white matter, and abnormal diffused bilateral white matter T2 hyperintensity suggesting leukoencephalopathy. Histopathological evaluation revealed prominent congested blood vessels suggestive of angiomatous changes and cystic areas suggestive of secondary gliosis.

Machine learning classifiers aid virtual screening for efficient design of mini-protein therapeutics

De novo design of mini-proteins (4-12 kDa) has recently been shown to produce new candidates for protein therapeutics. They are temperature stable molecules that bind to the drug target with high affinity for inhibiting its interactions. The development of mini-protein binders requires laboratory screening of tens of thousands of molecules for effective target binding. In this study we trained machine learning classifiers which can distinguish, with 90% accuracy and 80% precision, mini-protein binders from non-binding molecules designed for a particular target; this significantly reduces the number of mini protein candidates for experimental screening. Further, on the basis of our results we propose a multi-stage protocol where a small dataset (few hundred experimentally verified target-specific mini-proteins) can be used to train classifiers for improving the efficiency of mini-protein design for any specific target.

Aggressive angiomyxoma of the ischioanal fossa in a post-menopausal woman

Aggressive angiomyxoma is a rare mesenchymal tumour, primarily arising in the soft tissue of the pelvis and perineum in women of reproductive age. There is a paucity of evidence on optimal management because of the rarity of these tumours, but the consensus has been for surgical excision. We present the case of a 65-year-old woman who was admitted with left-sided buttock pain and initially diagnosed with a perianal abscess. She underwent examination under anaesthesia rectum with surgical excision of the lesion, subsequent histopathological and immunochemical analysis was suggestive of aggressive angiomyxoma. To complement our case report, we also present a literature review focusing on aggressive angiomyxoma in the ischioanal fossa (also known as the ischiorectal fossa) with only eight cases of primary aggressive angiomyxoma involving the ischioanal fossa documented to date. The primary aims of this case report and literature review are to familiarise clinicians with the clinical, histopathological and immunochemical features of these tumours, and to increase appreciation that despite the rarity of aggressive angiomyxoma, it might be considered in the differential diagnosis of ischioanal lesions.

Dynamic coupling analysis on plant sesquiterpene synthases provides leads for the identification of product specificity determinants

Sesquiterpene synthases catalyse cyclisation of farnesyl pyrophosphate to produce diverse sesquiterpenes. Despite utilising the same substrate and exhibiting significant sequence and structural homology, these enzymes form different products. Previous efforts were based on identifying the effect of divergent residues present at the catalytic binding pocket on the product specificity of these enzymes. However, the rationales deduced for the product specificity from these studies were not generic enough to be applicable to other phylogenetically distant members of this family. To address this problem, we have developed a novel approach combining sequence, structural and dynamical information of plant sesquiterpene synthases (SSQs) to predict product modulating residues (PMRs). We tested this approach on the SSQs with known PMRs and also on sesquisabinene synthase 1 (SaSQS1), a SSQ from Indian sandalwood. Our results show that the dynamical sectors of SSQs obtained from molecular dynamics simulation and their hydrophobicity and vicinity indices together provide leads for the identification of PMRs. The efficacy of the technique was tested on SaSQS1 using mutagenesis. To the best of our knowledge, this is a first technique of this kind which provides cues on PMRs of SSQs, with divergent phylogenetic relationship.

Structural studies on 10-hydroxygeraniol dehydrogenase: A novel linear substrate-specific dehydrogenase from Catharanthus roseus

Conversion of 10-hydroxygeraniol to 10-oxogeranial is a crucial step in iridoid biosynthesis. This reaction is catalyzed by a zinc-dependent alcohol dehydrogenase, 10-hydroxygeraniol dehydrogenase, belonging to the family of medium-chain dehydrogenase/reductase (MDR). Here, we report the crystal structures of a novel 10-hydroxygeraniol dehydrogenase from Catharanthus roseus in its apo and nicotinamide adenine dinucleotide phosphate (NADP+ ) bound forms. Structural analysis and docking studies reveal how subtle conformational differences of loops L1, L2, L3, and helix α9' at the orifice of the catalytic site confer differential activity of the enzyme toward various substrates, by modulating the binding pocket shape and volume. The present study, first of its kind, provides insights into the structural basis of substrate specificity of MDRs specific to linear substrates. Furthermore, comparison of apo and NADP+ bound structures suggests that the enzyme adopts open and closed states to facilitate cofactor binding.

Are UK and Ireland trauma and orthopaedic surgeons maintaining their research output?

INTRODUCTION

Healthcare faces growing challenges. With reports of diminishing research output from the UK and Ireland in the leading surgical journals, this study aimed to ascertain whether this trend had been echoed in the trauma and orthopaedic literature.

MATERIALS AND METHODS

Citable research output from the 10 globally leading trauma and orthopaedic journals was analysed from five individual years, over a 20-year period, to ascertain trends in absolute output, geographical mix, and level of evidence.

RESULTS

The overall number of published articles fell by 14.5%. North America saw the greatest decline (-8.0%), followed by Japan (-5.6%) and Europe (-3.3%). The UK and Ireland (+2.9%) and the rest of the world (+13.9%) saw rising output. A decline in lower (levels IV and V) and a rise in higher (levels I, II and III) quality evidence was observed. The UK and Ireland had a greater proportion of higher-quality studies than North America and Japan, but lower than Europe and the rest of the world. The impact factor of the leading journal rose from 4.47 to 7.01.

DISCUSSION

The research landscape has evolved, with leading journals placing greater emphasis on higher-quality evidence. UK and Irish research output remains stable, contributing 14% of the most highly cited publications in 2018, and challenging North America's dominance with a greater proportion of level I and II evidence in the leading journals.

CONCLUSION

With the growing emergence of Europe and the rest of the world, UK and Irish authors must build upon the region's output despite political challenges such as Brexit. Increasing international collaboration will continue to play an important role.

Comparison of hyperparathyroidism types and utility of dual radiopharmaceutical acquisition with Tc99m sestamibi and 123I for localization of rapid washout parathyroid adenomas

Tc99m-sestamibi dual-time imaging is a standard tool for localization of adenomas/hyperplasia in hyperparathyroidism. We investigated the degree and causes of localization failure among different types of hyperparathyroidism. Pre-operative parathyroid hormone levels and size of the gland were major determinants of Tc99m-sestamibi positivity; ¹²³I scan may be helpful in localization failures.

INTRODUCTION

Tc99m-sestamibi dual-time imaging is a standard tool for localization of adenomas/hyperplasia in hyperparathyroidism. However, parathyroid adenomas/hyperplasia has been reported to washout as fast as normal thyroid tissue ("rapid washout") which may lead to diagnostic failure. We aimed to evaluate the determinants of rapid washout and to determine the role of subtraction imaging for detection of parathyroid adenomas/hyperplasia with rapid washout.

METHODS

Retrospective analysis of patients with hyperparathyroidism who have undergone Tc99m-sestamibi dual-time imaging and parathyroid surgery. Rapid washout was correlated to the type of hyperparathyroidism in surgically confirmed cases. Biochemical and pathological data were reviewed.

RESULTS

A total of 135 hyperparathyroidism patients met the inclusion criteria. Ninety-six (72%), 29 (21%), and 10 (7%) had primary, secondary, and tertiary hyperparathyroidisms, respectively. Rapid washout was identified in 28/87 glands (32%), 14/53 glands (26%), and 1/16 glands (6%) with primary, secondary, and tertiary hyperparathyroidisms, respectively. Glands that were positive on late-phase Tc99m-sestamibi scans were significantly large being 1.7 (IQR 1.4-2.3) vs. 1.45 (IQR 1-2) cm (p = 0.003). High parathyroid hormone levels (PTH) were associated with early-phase Tc99m-sestamibi positivity in both primary (p = 0.01) and secondary hyperparathyroidism (p = 0.03) but not with last phase (p = 0.11, p = 0.37, respectively). Correlative imaging with subtraction scintigraphy was positive in 14/16 (87.5%) parathyroid adenomas.

CONCLUSION

Pre-operative PTH levels and size of the gland were major determinants of Tc99m-sestamibi positivity on early-phase Tc99m-sestamibi scans, whereas size is an independent predictor of late-phase Tc99m-sestamibi positivity. Subtraction scintigraphy might be a useful tool in suspected cases of rapid washout adenomas/hyperplasia.

Abstract P5-19-04: Psychosocial impact of a multi-modality surveillance program for women at high-risk for breast cancer

Purpose: To evaluate the psychosocial impact of semi-annual dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) screening in women at high-risk for breast cancer.

Background: For women with BRCA1 and BRCA2 mutations and/or a personal or family history of breast cancer, annual breast MRI has shown improved sensitivity and cancer detection compared to mammography. However, MRI's heightened sensitivity may lead to increased: false positives requiring additional follow-up biopsy/imaging; iatrogenic risk; and psychosocial distress, which all may negatively impact women's overall health-related quality of life.

Methods: Between 2004 and 2016, we assembled a prospective cohort of high-risk women undergoing semi-annual DCE-MRI and annual mammography. We reviewed a subset of this group. Participants completed psychosocial assessments at baseline and 6-month visits using the following measures: coping (MBSS); state/trait anxiety (STAI-S/T); depression (BDI-II); risk perception; and mental health (SF-36). Participants were classified according to Monitor or Blunter coping style. Mixed-effects logistic regressions models examined effects of demographics on psychosocial changes over time.

Results: 295 women were recruited to the study; 44% of the study participants had pathogenic mutations in BRCA1 or BRCA2 genes. 232 of 295 enrolled participants (78.6%) completed psychosocial assessments. For the total population: median age 44y (range: 21-73), 71% ≥college/post-graduate education; 84% Caucasian; 8% African American; 2% Latino; 99% with health insurance; 72% annual income of &gt;$60,000. One third of women had a personal cancer history. Participants were evenly split between baseline Monitoring and Blunting coping style (49% and 51%, respectively). No significant differences were found between demographics (age, race, income, mutation, cancer type, cancer history) or psychosocial factors (baseline trait anxiety (p =0.64), depression (p =0.65), SF36 global health (p=0.66). After adjusting for education, race, cancer history and coping, women with ≥$60,000 income had lower trait anxiety (p&lt;0.000) and greater mental health (p&lt;0.001) than those with &lt;$60,000 income. Over time, change in trait anxiety varied by coping (p=0.0006): Blunters did not experience significant changes in trait anxiety (p=0.072) while Monitors had significant diminished trait anxiety over time (p&lt;0.001). For depression, women with ≥$60,000 income and college educated had lower BDI-II depression (p&lt;0.000). Yet, women with a cancer history had significantly greater BDH-II depression (p= 0.048). Mental health over time varied by race as non-whites had greater gains in mental health (p=0.001) over time than whites (p=0.03).

Conclusion: Semi-annual DCE-MRI did not cause a significantly elevated state anxiety or depression, nor was there a significant decline in mental health over time for groups regardless of cancer history and genetic mutation status. Coping style may have an impact on psychosocial outcomes for those undergoing heightened surveillance over time.

Citation Format: Amico AL, Fang R, Raoul A, Wroblewski K, Nielsen S, Weipert C, Abe H, Sheth D, Romero I, Kulkarni K, Schacht D, Patrick-Miller L, Verp M, Bradbury AR, Hlubocky F, Olopade OI. Psychosocial impact of a multi-modality surveillance program for women at high-risk for breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-19-04.

Inadequate pelvic radiographs: implications of not getting it right the first time

Introduction Pelvic radiography is a frequent investigation. European guidelines aim to ensure appropriate use and adequate quality. When initial images are inadequate, repeat radiographs are often required, which may have significant patient safety and economic implications. Objectives The study aimed to assess the adequacy of pelvic imaging across three orthopaedic centres, to identify causes for inadequate imaging and to establish the cost of inadequate imaging from financial and patient safety perspectives. Methods Pelvic radiographs were identified on Picture Archiving and Communication System software at three UK hospitals. Radiographs were assessed against European guidelines and indications for repeat imaging were analysed. Results A total of 1,531 sequential pelvic radiographs were reviewed. The mean age of patients was 60 years (range 5 months to 101 years). Of this total, 51.9% of images were suboptimal, with no significant difference across the three hospitals (P > 0.05). Hospital 3 repeated radiographs in 6.3% of cases, compare with 18.1% and 19.7% at hospitals 1 and 2, respectively (P > 0.05). Hospital 3 identified pathology missed on the initial radiograph in 1% of cases, compared with 5.4% and 5.5% at hospitals 1 and 2, respectively (P > 0.05). Out-of-hours imaging is associated with a higher rate of suboptimal quality (69.1%) compared with normal working hours (51.3%; P = 0.006). Adequacy rates vary with age (χ ² = 43.62, P < 0.001). Risk of having a suboptimal radiograph increases above the age of 60-years (χ ² = 4.45, P < 0.05). The annual cost of repeat radiographs was £56,200 per hospital. Discussion and conclusion High rates of pelvic radiograph inadequacy can lead to missed pathology and the requirement for repeat imaging, which has significant patient safety and financial implications. Risk factors for inadequate radiographs include older patients and those having out-of-hours imaging.

Comorbid depressive symptoms in persistent delusional disorder: A retrospective study from India

Background

Previous studies have reported depressive symptoms in patients with persistent delusional disorder (PDD). Patients with PDD and depression may need antidepressants for treatment.

Aim

The aim of the study was to compare the sociodemographic profile, clinical presentation and treatment response in patients with PDD with and without comorbid depressive symptoms.

Methods

We conducted a retrospective chart review of patients diagnosed with PDD (ICD-10) from 2000 to 2014 (n = 455). We divided the patients into PDD + depression (n = 187) and PDD only (n = 268) for analysis.

Results

Of the 187 patients with PDD + D, only eighteen (3.9%) were diagnosed with syndromal depression. There were no significant differences in sociodemographic profile including sex, marital and socioeconomic status (all P > 0.05). PDD + D group had a significantly younger age at onset ([PDD + D: 30.6 9.2 years vs. PDD: 33.5 11.1 years]; t = 2.9, P < 0.05). There was no significant difference between the clinical presentation including mode of onset, the main theme of their delusion and secondary delusions (all P > 0.3). However, comorbid substance dependence was significantly higher in patients with PDD only. (χ2 = 5.3, P = 0.02). In terms of treatment, response to antipsychotics was also comparable ([> 75% response: PDD + D = 77/142 vs. PDD = 106/179); χ2 = 1.9, P = 0.3). There was a significant difference between the two groups in terms of antidepressant treatment ([PDD + D = 32/187; 17% vs PDD: 17/268; 6%), χ2 = 12.9, P = 0.001).

Discussion

Patients with PDD + D had significantly earlier onset of illness. These patients may require antidepressants for treatment.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Pharmacogenetic Association Between Glutamatergic Genes and Sri Treatment Response in Obsessive Compulsive Disorder

Introduction

Pharmacogenetic studies in obsessive-compulsive disorder (OCD) primarily focussing on serotonergic and dopaminergic polymorphisms, provided inconsistent findings. There is recent evidence for glutamatergic abnormalities in OCD.

Aims

Examine the association glutamatergic genes with serotonin reuptake inhibitor (SRI) response in OCD.

Objectives

To study pharmacogenetic association between SLC1A1 and GRIN2B polymorphisms with SRI response in OCD.

Methods

DSM-IV OCD patients were recruited from a specialty OCD clinic and evaluated using the Yale-Brown obsessive compulsive scale (YBOCS), Mini International Neuropsychiatric Interview (MINI) plus, Clinical Global Impression scale (CGI). They were subsequently reassessed with YBOCS and CGI. To study extreme phenotypes, we included only full responders (> 35% YBOCS improvement and CGI-I score of 1 or 2) to any SRI (n = 191) and non-responders (< 25% YBOCS improvement and CGI-I score ≥ 4) to adequate trial of at least two SRIs (n = 84). Partial responders were excluded. Genotyping was performed using an ABI9700 PCR machine.

Results

Genotype frequencies did not deviate significantly from the values predicted by the Hardy-Weinberg equation. Case-control association analyses revealed no significant association between genotype/allele frequencies with SRI response.

Conclusion

Our data does not show any association between polymorphisms in glutamatergic genes and SRI response in OCD though such associations have been found in other studies. More SNP's in the same gene could be responsible for the pharmacogenetic associations. More homogenous sample considering symptom dimensions and other phenotypic variables may be needed. It may be critical to go beyond “usual suspect” candidate gene research. In this regard, a novel approach to identify SRI response biomarkers is the use of cellular models.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Much more than just another guidance document

As a pediatric hematologist oncologist with clinical and research interests in thrombosis in high-risk pediatric populations, and also as a member of the ISTH Early Career Task Force, I had the opportunity to develop a guidance document on 'Thromboprophylaxis for central venous catheters in the pediatric population' for the 'Guidelines and Guidance Documents' committee. In this communication, I share my experiences to date; I discuss my excitement and initial success, the steep learning curve required to build research acumen, the lessons learnt, and the opportunities and challenges faced. My experience with preparing the guidance document was much more than writing 'just another guidance document'.

Assessment of Myeloperoxidase and Nitric Levels around Dental Implants and Natural Teeth as a Marker of Inflammation: A Comparative Study

INTRODUCTION

Dental implants form the mainstay of dental treatment involving rehabilitation of missing teeth. One of the major concerns for the clinicians doing dental implants is the postsurgical failure of dental implants. Success of dental implants is dependent upon the skills of the surgeon and the amount and quality of the bone remaining at the edentulous area where dental implant has to be placed. Myeloperoxidase (MPO) and nitrites are few of the enzymes and molecules which are said to be altered in inflammation. However, their exact role in the inflammatory processes around natural tooth and dental implant is still unclear. Hence we comparatively evaluated the levels of MPO and nitrites in the areas around the dental implants and natural teeth.

MATERIALS AND METHODS

The present study comprises 42 patients who underwent prosthetic rehabilitation by dental implants from 2011 to 2014. Depth of probing value (DP), score of plaque index (SPI), gingival index (GI), and index of gingival bleeding time (GBT) were evaluated for the assessment of the periimplant soft tissue changes. Assessment of inflammation around the dental implant surface and around natural tooth was done based on the readings of these parameters. For the measurement of the MPO levels, spectrophotometric MPO assay was used. All the results were analyzed by Statistical Package for the Social Sciences (SPSS) software.

RESULTS

The mean plaque index values were 1.56 and 0.97 in periodontitis cases of natural teeth and inflamed cases of dental implants respectively. While comparing mean plaque index, mean probing depth, and mean gingival bleeding index in between the two groups, significant difference was obtained. Mean MPO concentration in periodontitis and gingivitis cases in natural teeth were 0.683 and 0.875 U/μL, while in inflamed dental implant cases, the mean value was 0.622 U/μL. While comparing the total MPO levels, total nitrite levels, and total nitrite concentration in between two study groups, significant difference was obtained. On comparing the healthy and periodontitis cases in natural teeth, significant difference was obtained.

CONCLUSION

In the inflammatory processes occurring around dental implant and natural teeth, MPO and NO make some amount of significant contribution.

CLINICAL SIGNIFICANCE

The present study enforces on the role of MPO and nitrite as diagnostic and prognostic marker.

A comparison of risperidone and olanzapine in the acute treatment of persistent delusional disorder: Data from a retrospective chart review

Introduction

There is a lack of pharmacological trials studying drug response in Persistent Delusional Disorder (PDD) to guide clinical practice. Available reviews of retrospective data indicate good response to second-generation antipsychotics, but even such data from India is sparse.

Objectives and aims

We aimed to compare the response of acute PDD to risperidone and olanzapine in our retrospective review.

Methods

We conducted a retrospective chart review of patients diagnosed with PDD (ICD-10) from 2000 to 2014 (n = 455) at our Center. We selected the data of patients prescribed either olanzapine or risperidone for the purpose of this analysis. We extracted data about dose, drug compliance and response, adverse effects, number of follow-up visits and hospitalizations. The study was approved by the Institute Ethics Committee.

Results

A total of 280/455 (61%) were prescribed risperidone and 86/455 (19%) olanzapine. The remaining (n = 89; 20%) had received other antipsychotics. The two groups were comparable in socio-demographic and clinical characteristics of PDD. Compliance was good and comparable in both groups (> 80%, P = 0.2). Response to treatment was comparable in both groups (85% partial response and > 52% good response, all P > 0.3). Olanzapine was effective at lower mean chlorpromazine equivalents than risperidone (240 vs. 391, P < 0.05).

Conclusion

Our study indicates a good response to both risperidone and olanzapine, if compliance to treatment can be ensured. In the absence of specific treatment guidelines for PDD, second-generation antipsychotics like risperidone and olanzapine offer good treatment options for this infrequently encountered and difficult to treat psychiatric disorder.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

A self-assembling β-peptide hydrogel for neural tissue engineering

We report a new class of β-peptide based hydrogel for neural tissue engineering. Our β-peptide forms a network of nanofibres in aqueous solution, resulting in a stable hydrogel at physiological conditions. The hydrogel shows excellent compatibility with neural cells and provides a suitable environment for cells to adhere and proliferate.

Atomic-Resolution Structures of the APC/C Subunits Apc4 and the Apc5 N-Terminal Domain

Many essential biological processes are mediated by complex molecular machines comprising multiple subunits. Knowledge on the architecture of individual subunits and their positions within the overall multimeric complex is key to understanding the molecular mechanisms of macromolecular assemblies. The anaphase-promoting complex/cyclosome (APC/C) is a large multisubunit complex that regulates cell cycle progression by ubiquitinating cell cycle proteins for proteolysis by the proteasome. The holo-complex is composed of 15 different proteins that assemble to generate a complex of 20 subunits. Here, we describe the crystal structures of Apc4 and the N-terminal domain of Apc5 (Apc5(N)). Apc4 comprises a WD40 domain split by a long α-helical domain, whereas Apc5(N) has an α-helical fold. In a separate study, we had fitted these atomic models to a 3.6-Å-resolution cryo-electron microscopy map of the APC/C. We describe how, in the context of the APC/C, regions of Apc4 disordered in the crystal assume order through contacts to Apc5, whereas Apc5(N) shows small conformational changes relative to its crystal structure. We discuss the complementary approaches of high-resolution electron microscopy and protein crystallography to the structure determination of subunits of multimeric complexes.

Cervical epidural anaesthesia with ropivacaine for modified radical mastectomy

BACKGROUND

Cervical epidural anaesthesia (CEA) using local anesthetics (LA) is a well established technique for the surgeries in the neck, chest and upper arms. Recently ropivacaine is introduced with better safety profile.

OBJECTIVES

The aim was to observe the safety of Cervical epidural anaesthesia as an anaesthetic technique and to compare the efficacy of epidural 0.25% bupivacaine with 0.375% ropivacaine for radical mastectomies.

METHODS

A double blind study was conducted on 40 ASA grade I / II females who received CEA with 10 ml of 0.25% of bupivacaine +25μg of fentanyl in group B (n=20) and 10 ml of 0.375% of ropivacaine +25μg of fentanyl in group R (n=20) epidurally. Assessment of the block, vital monitoring and complications noted.

RESULTS

No significant differences observed in the onset of sensory block (5.05 min and 5.4 min in group B and R respectively, P>0.05).The mean motor blockade score, time to achieve complete blockade and time to grade I motor recovery was significantly longer in group B (2.3, 22.5 and 79.5 minutes respectively) as compared to group R (1.5, 18.3 and 66.3 minutes respectively, P<0.05). Respiratory distress developed in two patients of group B that required general anaesthesia (GA) with intubation.

CONCLUSION

Use of 0.37% ropivacaine is safer than 0.25% bupivacaine for CEA for radical mastectomy. It provides good surgical anaesthesia with lesser degree of motor blockade and the respiratory effects.

Sequestrated meningocoele within a naevus sebaceous of Jadassohn on the scalp of a child

Sequestrated meningocoele is an uncommon developmental anomaly in which meningothelial elements are found in the skin or subcutaneous tissue without underlying bony defect. By contrast, naevus sebaceous of Jadassohn (NSJ) is a circumscribed hamartomatous lesion occurring in about 0.3% of newborns. We report a child with a histologically confirmed sequestrated meningocoele within an NSJ on his scalp vertex. Such an occurrence has not been reported previously.

Mechanism of farnesylated CAAX protein processing by the intramembrane protease Rce1

CAAX proteins have essential roles in multiple signalling pathways, controlling processes such as proliferation, differentiation and carcinogenesis. The ∼120 mammalian CAAX proteins function at cellular membranes and include the Ras superfamily of small GTPases, nuclear lamins, the γ-subunit of heterotrimeric GTPases, and several protein kinases and phosphatases. The proper localization of CAAX proteins to cell membranes is orchestrated by a series of post-translational modifications of the carboxy-terminal CAAX motifs (where C is cysteine, A is an aliphatic amino acid and X is any amino acid). These reactions involve prenylation of the cysteine residue, cleavage at the AAX tripeptide and methylation of the carboxyl-prenylated cysteine residue. The major CAAX protease activity is mediated by Rce1 (Ras and a-factor converting enzyme 1), an intramembrane protease (IMP) of the endoplasmic reticulum. Information on the architecture and proteolytic mechanism of Rce1 has been lacking. Here we report the crystal structure of a Methanococcus maripaludis homologue of Rce1, whose endopeptidase specificity for farnesylated peptides mimics that of eukaryotic Rce1. Its structure, comprising eight transmembrane α-helices, and catalytic site are distinct from those of other IMPs. The catalytic residues are located ∼10 Å into the membrane and are exposed to the cytoplasm and membrane through a conical cavity that accommodates the prenylated CAAX substrate. We propose that the farnesyl lipid binds to a site at the opening of two transmembrane α-helices, which results in the scissile bond being positioned adjacent to a glutamate-activated nucleophilic water molecule. This study suggests that Rce1 is the founding member of a novel IMP family, the glutamate IMPs.

The four canonical tpr subunits of human APC/C form related homo-dimeric structures and stack in parallel to form a TPR suprahelix

The anaphase-promoting complex or cyclosome (APC/C) is a large E3 RING-cullin ubiquitin ligase composed of between 14 and 15 individual proteins. A striking feature of the APC/C is that only four proteins are involved in directly recognizing target proteins and catalyzing the assembly of a polyubiquitin chain. All other subunits, which account for >80% of the mass of the APC/C, provide scaffolding functions. A major proportion of these scaffolding subunits are structurally related. In metazoans, there are four canonical tetratricopeptide repeat (TPR) proteins that form homo-dimers (Apc3/Cdc27, Apc6/Cdc16, Apc7 and Apc8/Cdc23). Here, we describe the crystal structure of the N-terminal homo-dimerization domain of Schizosaccharomyces pombe Cdc23 (Cdc23(Nterm)). Cdc23(Nterm) is composed of seven contiguous TPR motifs that self-associate through a related mechanism to those of Cdc16 and Cdc27. Using the Cdc23(Nterm) structure, we generated a model of full-length Cdc23. The resultant "V"-shaped molecule docks into the Cdc23-assigned density of the human APC/C structure determined using negative stain electron microscopy (EM). Based on sequence conservation, we propose that Apc7 forms a homo-dimeric structure equivalent to those of Cdc16, Cdc23 and Cdc27. The model is consistent with the Apc7-assigned density of the human APC/C EM structure. The four canonical homo-dimeric TPR proteins of human APC/C stack in parallel on one side of the complex. Remarkably, the uniform relative packing of neighboring TPR proteins generates a novel left-handed suprahelical TPR assembly. This finding has implications for understanding the assembly of other TPR-containing multimeric complexes.

Building a pseudo-atomic model of the anaphase-promoting complex

The anaphase-promoting complex (APC/C) is a large E3 ubiquitin ligase that regulates progression through specific stages of the cell cycle by coordinating the ubiquitin-dependent degradation of cell-cycle regulatory proteins. Depending on the species, the active form of the APC/C consists of 14-15 different proteins that assemble into a 20-subunit complex with a mass of approximately 1.3 MDa. A hybrid approach of single-particle electron microscopy and protein crystallography of individual APC/C subunits has been applied to generate pseudo-atomic models of various functional states of the complex. Three approaches for assigning regions of the EM-derived APC/C density map to specific APC/C subunits are described. This information was used to dock atomic models of APC/C subunits, determined either by protein crystallography or homology modelling, to specific regions of the APC/C EM map, allowing the generation of a pseudo-atomic model corresponding to 80% of the entire complex.

Structure of the mitotic checkpoint complex

In mitosis, the spindle assembly checkpoint (SAC) ensures genome stability by delaying chromosome segregation until all sister chromatids have achieved bipolar attachment to the mitotic spindle. The SAC is imposed by the mitotic checkpoint complex (MCC), whose assembly is catalysed by unattached chromosomes and which binds and inhibits the anaphase-promoting complex/cyclosome (APC/C), the E3 ubiquitin ligase that initiates chromosome segregation. Here, using the crystal structure of Schizosaccharomyces pombe MCC (a complex of mitotic spindle assembly checkpoint proteins Mad2, Mad3 and APC/C co-activator protein Cdc20), we reveal the molecular basis of MCC-mediated APC/C inhibition and the regulation of MCC assembly. The MCC inhibits the APC/C by obstructing degron recognition sites on Cdc20 (the substrate recruitment subunit of the APC/C) and displacing Cdc20 to disrupt formation of a bipartite D-box receptor with the APC/C subunit Apc10. Mad2, in the closed conformation (C-Mad2), stabilizes the complex by optimally positioning the Mad3 KEN-box degron to bind Cdc20. Mad3 and p31(comet) (also known as MAD2L1-binding protein) compete for the same C-Mad2 interface, which explains how p31(comet) disrupts MCC assembly to antagonize the SAC. This study shows how APC/C inhibition is coupled to degron recognition by co-activators.

The structure of the 26S proteasome subunit Rpn2 reveals its PC repeat domain as a closed toroid of two concentric α-helical rings

The 26S proteasome proteolyses ubiquitylated proteins and is assembled from a 20S proteolytic core and two 19S regulatory particles (19S-RP). The 19S-RP scaffolding subunits Rpn1 and Rpn2 function to engage ubiquitin receptors. Rpn1 and Rpn2 are characterized by eleven tandem copies of a 35-40 amino acid repeat motif termed the proteasome/cyclosome (PC) repeat. Here, we reveal that the eleven PC repeats of Rpn2 form a closed toroidal structure incorporating two concentric rings of α helices encircling two axial α helices. A rod-like N-terminal domain consisting of 17 stacked α helices and a globular C-terminal domain emerge from one face of the toroid. Rpn13, an ubiquitin receptor, binds to the C-terminal 20 residues of Rpn2. Rpn1 adopts a similar conformation to Rpn2 but differs in the orientation of its rod-like N-terminal domain. These findings have implications for understanding how 19S-RPs recognize, unfold, and deliver ubiquitylated substrates to the 20S core.