Interventions for Managing Late Gastrointestinal Symptoms Following Pelvic Radiotherapy: a Systematic Review and Meta-analysis.

AIMS: Pelvic radiotherapy can induce gastrointestinal injury and symptoms, which can affect quality of life. We assessed interventions for managing these symptoms. MATERIALS AND METHODS: A review of randomised controlled trials published between January 1990 and June 2023 from databases including MEDLINE, EMBASE, CENTRAL, CINAHL, clinicaltrials.gov, ISRCTN and grey literature sources was conducted. Meta-analyses were carried out using the DerSimonian and Laird random effects model to produce overall treatment differences with 95% confidence intervals. RESULTS: Twenty-eight studies (2392 participants) of varying methodological quality were included. 4% formalin was superior to sucralfate for improving gastrointestinal symptom score (standardised mean difference [SMD] -1.07, 95% confidence interval -1.48 to -0.65). Argon plasma coagulation (APC) was inferior to sucralfate (SMD 1.22, 95% confidence interval 0.84 to 1.59). Counselling positively influenced symptom score (SMD -0.53, 95% confidence interval -0.76 to -0.29), whereas hyperbaric oxygen therapy showed conflicting results. Sucralfate combined with APC increased endoscopic markers of moderate-severe bleeding versus APC alone (risk ratio 2.26, 95% confidence interval 1.12 to 4.55). No definite conclusions on pain, incontinence, diarrhoea, tenesmus or quality of life interventions were confirmed. CONCLUSIONS: Small study sizes, methodological quality and heterogeneity limit support of any individual intervention. APC and 4% formalin seem to be promising interventions, with further larger randomised controlled trials now warranted.

Retinal Vascular Occlusion after COVID-19 Vaccination: More Coincidence than Causal Relationship? Data from a Retrospective Multicentre Study.

BACKGROUND: To investigate whether vaccination against SARS-CoV-2 is associated with the onset of retinal vascular occlusive disease (RVOD). METHODS: In this multicentre study, data from patients with central and branch retinal vein occlusion (CRVO and BRVO), central and branch retinal artery occlusion (CRAO and BRAO), and anterior ischaemic optic neuropathy (AION) were retrospectively collected during a 2-month index period (1 June-31 July 2021) according to a defined protocol. The relation to any previous vaccination was documented for the consecutive case series. Numbers of RVOD and COVID-19 vaccination were investigated in a case-by-case analysis. A case-control study using age- and sex-matched controls from the general population (study participants from the Gutenberg Health Study) and an adjusted conditional logistic regression analysis was conducted. RESULTS: Four hundred and twenty-one subjects presenting during the index period (61 days) were enrolled: one hundred and twenty-one patients with CRVO, seventy-five with BRVO, fifty-six with CRAO, sixty-five with BRAO, and one hundred and four with AION. Three hundred and thirty-two (78.9%) patients had been vaccinated before the onset of RVOD. The vaccines given were BNT162b2/BioNTech/Pfizer (n = 221), followed by ChadOx1/AstraZeneca (n = 57), mRNA-1273/Moderna (n = 21), and Ad26.COV2.S/Johnson & Johnson (n = 11; unknown n = 22). Our case-control analysis integrating population-based data from the GHS yielded no evidence of an increased risk after COVID-19 vaccination (OR = 0.93; 95% CI: 0.60-1.45, p = 0.75) in connection with a vaccination within a 4-week window. CONCLUSIONS: To date, there has been no evidence of any association between SARS-CoV-2 vaccination and a higher RVOD risk.

Vascular control of kidney epithelial transporters.

A major pathway in hypertension pathogenesis involves direct activation of ANG II type 1 (AT1) receptors in the kidney, stimulating Na+ reabsorption. AT1 receptors in tubular epithelia control expression and stimulation of Na+ transporters and channels. Recently, we found reduced blood pressure and enhanced natriuresis in mice with cell-specific deletion of AT1 receptors in smooth muscle (SMKO mice). Although impaired vasoconstriction and preserved renal blood flow might contribute to exaggerated urinary Na+ excretion in SMKO mice, we considered whether alterations in Na+ transporter expression might also play a role; therefore, we carried out proteomic analysis of key Na+ transporters and associated proteins. Here, we show that levels of Na+-K+-2Cl- cotransporter isoform 2 (NKCC2) and Na+/H+ exchanger isoform 3 (NHE3) are reduced at baseline in SMKO mice, accompanied by attenuated natriuretic and diuretic responses to furosemide. During ANG II hypertension, we found widespread remodeling of transporter expression in wild-type mice with significant increases in the levels of total NaCl cotransporter, phosphorylated NaCl cotransporter (Ser71), and phosphorylated NKCC2, along with the cleaved, activated forms of the α- and γ-epithelial Na+ channel. However, the increases in α- and γ-epithelial Na+ channel with ANG II were substantially attenuated in SMKO mice. This was accompanied by a reduced natriuretic response to amiloride. Thus, enhanced urinary Na+ excretion observed after cell-specific deletion of AT1 receptors from smooth muscle cells is associated with altered Na+ transporter abundance across epithelia in multiple nephron segments. These findings suggest a system of vascular-epithelial in the kidney, modulating the expression of Na+ transporters and contributing to the regulation of pressure natriuresis.NEW & NOTEWORTHY The use of drugs to block the renin-angiotensin system to reduce blood pressure is common. However, the precise mechanism for how these medications control blood pressure is incompletely understood. Here, we show that mice lacking angiotensin receptors specifically in smooth muscle cells lead to alternation in tubular transporter amount and function. Thus, demonstrating the importance of vascular-tubular cross talk in the control of blood pressure.

An Epilepsy-Associated GRIN2A Rare Variant Disrupts CaMKIIα Phosphorylation of GluN2A and NMDA Receptor Trafficking.

Rare variants in GRIN genes, which encode NMDAR subunits, are strongly associated with neurodevelopmental disorders. Among these, GRIN2A, which encodes the GluN2A subunit of NMDARs, is widely accepted as an epilepsy-causative gene. Here, we functionally characterize the de novo GluN2A-S1459G mutation identified in an epilepsy patient. We show that S1459 is a CaMKIIα phosphorylation site, and that endogenous phosphorylation is regulated during development and in response to synaptic activity in a dark rearing model. GluN2A-S1459 phosphorylation results in preferential binding of NMDARs to SNX27 and a corresponding decrease in PSD-95 binding, which consequently regulates NMDAR trafficking. Furthermore, the epilepsy-associated GluN2A-S1459G variant displays defects in interactions with both SNX27 and PSD-95, resulting in trafficking deficits, reduced spine density, and decreased excitatory synaptic transmission. These data demonstrate a role for CaMKIIα phosphorylation of GluN2A in receptor targeting and implicate NMDAR trafficking defects as a link to epilepsy.

Neuroligins and Neurodevelopmental Disorders: X-Linked Genetics.

Autism spectrum disorder (ASD) is a neurodevelopmental disorder that results in social-communication impairments, as well as restricted and repetitive behaviors. Moreover, ASD is more prevalent in males, with a male to female ratio of 4 to 1. Although the underlying etiology of ASD is generally unknown, recent advances in genome sequencing have facilitated the identification of a host of associated genes. Among these, synaptic proteins such as cell adhesion molecules have been strongly linked with ASD. Interestingly, many large genome sequencing studies exclude sex chromosomes, which leads to a shift in focus toward autosomal genes as targets for ASD research. However, there are many genes on the X chromosome that encode synaptic proteins, including strong candidate genes. Here, we review findings regarding two members of the neuroligin (NLGN) family of postsynaptic adhesion molecules, NLGN3 and NLGN4. Neuroligins have multiple isoforms (NLGN1-4), which are both autosomal and sex-linked. The sex-linked genes, NLGN3 and NLGN4, are both on the X chromosome and were among the first few genes to be linked with ASD and intellectual disability (ID). In addition, there is a less studied human neuroligin on the Y chromosome, NLGN4Y, which forms an X-Y pair with NLGN4X. We will discuss recent findings of these neuroligin isoforms regarding function at the synapse in both rodent models and human-derived differentiated neurons, and highlight the exciting challenges moving forward to a better understanding of ASD/ID.

A Cluster of Autism-Associated Variants on X-Linked NLGN4X Functionally Resemble NLGN4Y.

Autism spectrum disorder (ASD) is more prevalent in males; however, the etiology for this sex bias is not well understood. Many mutations on X-linked cell adhesion molecule NLGN4X result in ASD or intellectual disability. NLGN4X is part of an X-Y pair, with NLGN4Y sharing ∼97% sequence homology. Using biochemistry, electrophysiology, and imaging, we show that NLGN4Y displays severe deficits in maturation, surface expression, and synaptogenesis regulated by one amino acid difference with NLGN4X. Furthermore, we identify a cluster of ASD-associated mutations surrounding the critical amino acid in NLGN4X, and these mutations phenocopy NLGN4Y. We show that NLGN4Y cannot compensate for the functional deficits observed in ASD-associated NLGN4X mutations. Altogether, our data reveal a potential pathogenic mechanism for male bias in NLGN4X-associated ASD.

Isoform-specific cleavage of neuroligin-3 reduces synapse strength.

The assembly and maintenance of synapses are dynamic processes that require bidirectional contacts between the pre- and postsynaptic structures. A network of adhesion molecules mediate this physical interaction between neurons. How synapses are disassembled and if there are distinct mechanisms that govern the removal of specific adhesion molecules remain unclear. Here, we report isoform-specific proteolytic cleavage of neuroligin-3 in response to synaptic activity and protein kinase C signaling resulting in reduced synapse strength. Although neuroligin-1 and neuroligin-2 are not directly cleaved by this pathway, when heterodimerized with neuroligin-3, they too undergo proteolytic cleavage. Thus protein kinase C-dependent cleavage is mediated through neuroligin-3. Recent studies on glioma implicate the neuroligin-3 ectodomain as a mitogen. Here we demonstrate: (1) there are mechanisms governing specific adhesion molecule remodeling; (2) neuroligin-3 is a key regulator of neuroligin cleavage events; and (3) there are two cleavage pathways; basal and activity-dependent that produce the mitogenic form of neuroligin-3.

Mechanistical Insights into the Bioconjugation Reaction of Triazolinediones with Tyrosine.

The bioconjugation at tyrosine residues using cyclic diazodicarboxamides, especially 4-substituted 3 H-1,2,4-triazole-3,5(4 H)-dione (PTAD), is a highly enabling synthetic reaction because it can be employed for orthogonal and site-selective (multi)functionalizations of native peptides and proteins. Despite its importance, the underlying mechanisms have not been thoroughly investigated. The reaction can proceed along four distinctive pathways: (i) the SEAr path, (ii) along a pericyclic group transfer pathway (a classical ene reaction), (iii) along a stepwise reaction path, or (iv) along an unusual higher order concerted pericyclic mechanism. The product mixtures obtained from reactions of PTAD with 2,4-unsubstituted phenolate support the SEAr mechanism, but it remains unclear if other mechanisms also take place. In the present work, the various mechanisms are compared using high-level quantum chemistry approaches for the model reaction of 4 H,3 H-1,2,4-triazole-3,5(4 H)-dione (HTAD) with p-cresol and p-cresolate. In a protic solvent (water), the barriers of the SEAr mechanism and the ene reaction are similar but still too high to explain the available experimental observations. This is only possible if the SEAr reaction of cresolate with HTAD is taken into account for which nearly vanishing barriers are computed. This satisfactorily explains measured conversion rates in buffered aqueous solutions and the strong activation effects observed upon addition of bases.

Vascular type 1 angiotensin receptors control blood pressure by augmenting peripheral vascular resistance in female mice.

Angiotensin II (ANG II) is a major mediator of hypertension pathogenesis. In addition, there are well-documented differences in expression of the renin-angiotensin system (RAS) components and ANG II responses between males and females, which may explain sex differences in blood pressure (BP) and hypertension epidemiology. We previously showed that type 1A angiotensin (AT1A) receptors in vascular smooth muscle cells (VSMCs) play a critical role in BP regulation and hypertension pathogenesis, but these studies were carried out in male mice. Therefore, the major goal of the current studies was to examine the impact of VSMC AT1A receptors on BP and hypertension pathogenesis in female mice. We found that elimination of VSMC AT1A receptors in female mice reduced (≈8 mmHg) baseline BP without altering sodium sensitivity. The severity of ANG II-induced hypertension was diminished (≈33% reduction in BP), particularly during the last 2 wk of chronic ANG II infusion, compared with controls, but natriuresis was not altered during the first 5 days of ANG II infusion. Urinary norepinephrine levels were enhanced in female SMKO compared with control mice. There was a virtually complete elimination of ANG II-induced kidney hemodynamic responses with attenuation of acute vasoconstrictor responses in the systemic vasculature. These findings demonstrate that direct vascular actions of AT1A receptors play a prominent role in BP control and hypertension pathogenesis in female mice.

Application of multiplexed kinase inhibitor beads to study kinome adaptations in drug-resistant leukemia.

Protein kinases play key roles in oncogenic signaling and are a major focus in the development of targeted cancer therapies. Imatinib, a BCR-Abl tyrosine kinase inhibitor, is a successful front-line treatment for chronic myelogenous leukemia (CML). However, resistance to imatinib may be acquired by BCR-Abl mutations or hyperactivation of Src family kinases such as Lyn. We have used multiplexed kinase inhibitor beads (MIBs) and quantitative mass spectrometry (MS) to compare kinase expression and activity in an imatinib-resistant (MYL-R) and -sensitive (MYL) cell model of CML. Using MIB/MS, expression and activity changes of over 150 kinases were quantitatively measured from various protein kinase families. Statistical analysis of experimental replicates assigned significance to 35 of these kinases, referred to as the MYL-R kinome profile. MIB/MS and immunoblotting confirmed the over-expression and activation of Lyn in MYL-R cells and identified additional kinases with increased (MEK, ERK, IKKα, PKCß, NEK9) or decreased (Abl, Kit, JNK, ATM, Yes) abundance or activity. Inhibiting Lyn with dasatinib or by shRNA-mediated knockdown reduced the phosphorylation of MEK and IKKα. Because MYL-R cells showed elevated NF-κB signaling relative to MYL cells, as demonstrated by increased IκBα and IL-6 mRNA expression, we tested the effects of an IKK inhibitor (BAY 65-1942). MIB/MS and immunoblotting revealed that BAY 65-1942 increased MEK/ERK signaling and that this increase was prevented by co-treatment with a MEK inhibitor (AZD6244). Furthermore, the combined inhibition of MEK and IKKα resulted in reduced IL-6 mRNA expression, synergistic loss of cell viability and increased apoptosis. Thus, MIB/MS analysis identified MEK and IKKα as important downstream targets of Lyn, suggesting that co-targeting these kinases may provide a unique strategy to inhibit Lyn-dependent imatinib-resistant CML. These results demonstrate the utility of MIB/MS as a tool to identify dysregulated kinases and to interrogate kinome dynamics as cells respond to targeted kinase inhibition.

Comparison of RIPASA and Alvarado scores for the diagnosis of acute appendicitis.

INTRODUCTION: The accuracy of the Alvarado score in diagnosing acute appendicitis in an Asian population has been disappointingly low. We prospectively compared the RIPASA score with the Alvarado score for the diagnosis of acute appendicitis. METHODS: 200 consecutive patients who presented to the Accident and Emergency Department with right iliac fossa pain were recruited in the study. Both the RIPASA and Alvarado scores were derived, but decisions for appendicectomy were based on clinical judgement. Receiver operating curve (ROC), sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for both scoring systems were calculated. RESULTS: Only 192 out of the 200 patients who satisfied the inclusion and exclusion criteria were included in the analysis. At the optimal cut-off threshold score of 7.5 derived from the ROC, the sensitivity, specificity, PPV, NPV and diagnostic accuracy of the RIPASA score were 98.0 percent, 81.3 percent, 85.3 percent, 97.4 percent and 91.8 percent, respectively. At the cut-off threshold score of 7.0 for the Alvarado score, the sensitivity, specificity, PPV, NPV and diagnostic accuracy were 68.3 percent, 87.9 percent, 86.3 percent, 71.4 percent and 86.5 percent, respectively. The RIPASA score correctly classified 98 percent of all patients confirmed with histological acute appendicitis to the high-probability group (RIPASA score greater than 7.5) compared with 68.3 percent with the Alvarado score (Alvarado score greater than 7.0; p-value less than 0.0001). CONCLUSION: The RIPASA score at a cut-off threshold total score of 7.5 is a better diagnostic scoring system than the Alvarado score for the diagnosis of acute appendicitis in our local setting.

t(4;11) leukemias display addiction to MLL-AF4 but not to AF4-MLL.

The most frequent MLL-gene rearrangement found in leukemia is a reciprocal translocation with AF4 on chromosome 4 resulting in the formation of the MLL-AF4 and the AF4-MLL fusion genes. The oncogenic role of MLL-AF4 is documented but the significance of the reciprocal product - AF4-MLL in leukemia is less clear. In the human leukemia cell lines - RS4;11 and SEMK2-M1, both of which express MLL-AF4 and AF4-MLL, we knocked down the expression of AF4-MLL using siRNA. Loss of AF4-MLL had no effect on the growth of either RS4;11 or SEMK2-M1 cells. Furthermore, in SEMK2-M1 cells there were no changes in cell cycle or apoptosis with loss of AF4-MLL. In contrast, knockdown of MLL-AF4 significantly inhibited growth of both RS4;11 and SEMK2-M1. Additionally, in SEMK2-M1 cells, loss of MLL-AF4 led to G2/M cell cycle arrest and increased apoptosis. Overall, these results demonstrate that in t(4;11) leukemia, the MLL-AF4 fusion protein is critical for leukemia cell proliferation and survival while the AF4-MLL fusion product is dispensable.

Development of the RIPASA score: a new appendicitis scoring system for the diagnosis of acute appendicitis.

INTRODUCTION: Acute appendicitis is one of the most common surgical emergencies. The Alvarado and modified Alvarado scores have been developed to aid diagnosis, but both scoring systems have poor sensitivity and specificity when applied in Middle Eastern and Asian populations. The aim of this study was to develop a new scoring system that is suitable for the local population. METHODS: Clinical data from 312 patients who had undergone an emergency appendicectomy was retrospectively collected and used to generate 15 parameters. The probability was calculated and a score of 0.5, 1.0 or 2.0 was allocated to each parameter. The receiver operating curve (ROC), sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the new scoring system were derived using the StatsDirect statistical software. RESULTS: The 15 parameters and the scores generated were age (less than 40 years is 1 point; greater than 40 years is 0.5 point), gender (male is 1 point; female is 0.5 point), right iliac fossa (RIF) pain (0.5 point), migration of pain to RIF (0.5 point), nausea and vomiting (1 point), anorexia (1 point), duration of symptoms (less than 48 hours is 1 point; more than 48 hours is 0.5 point), RIF tenderness (1 point), guarding (2 points), rebound tenderness (1 point), Rovsing's sign (2 points), fever (1 point), raised white cell count (1 point), negative urinalysis (1 point) and foreign national registration identity card (1 point). The optimal cut-off threshold score from the ROC was 7.5, with a sensitivity of 88 percent, a specificity of 67 percent, a PPV of 93 percent and an NPV of 53 percent. The negative appendicectomy rate decreased significantly from 16.3 percent to 6.9 percent, which was a 9.4 percent reduction (p is 0.0007). CONCLUSION: The new appendicitis scoring system looked promising when applied to our settings, and had a better sensitivity and specificity than the Alvarado score when applied to Asian populations. A significant reduction in the negative appendicectomy rate was also predicted. A prospective evaluation of this new appendicitis scoring system, referred to as the RIPASA score, is ongoing.

Peptide-based interference of the transmembrane domain of neuropilin-1 inhibits glioma growth in vivo.

Angiogenesis in glioblastoma is largely dependent on vascular endothelial growth factor (VEGF) signalling. Consistently, the VEGF coreceptor NRP1 promotes angiogenesis and tumour growth in gliomas. Here, we provide data showing that an innovative peptidic tool targeting the transmembrane domain of NRP1 efficiently blocks rat and human glioma growth in vivo. We show both in vivo and in vitro that the antitumour effect results from the anti-proliferative, anti-migratory and anti-angiogenic properties of the compound. The proposed NRP1 antagonizing peptide is therefore a promising novel class of anti-angiogenic drugs that might prolong glioma patient survival. Our results finally show for the first time that the transmembrane domain of important signalling receptors can be antagonized in vivo thereby providing a new avenue towards the development of atypical antagonists with strong therapeutic potential.

Implementation of and compliance with NICE guidelines in the secondary prevention of osteoporotic fractures in postmenopausal women.

Osteoporosis affects more than 1.2 million women in England and Wales. Hip fractures are associated with increased mortality. The total cost of treating osteoporotic fractures in postmenopausal women is expected to rise to pound 2.1 billion by 2010. The National Institute for Health and Clinical Excellence (NICE) has issued guidelines for the secondary prevention of osteoporotic fractures in postmenopausal women. The objective of this study was to review the NICE guidelines and to assess the implementation of and compliance with these guidelines in a district general hospital.

Analysis of distortion in preserved bite mark skin.

In addition to other methods for conservation of bite mark evidence, preservation of actual skin from deceased victims is often suggested. This study was undertaken to analyze the dimensional stability of such specimens. Utilizing a prefabricated template, marks approximating "bites" were made in postmortem skin of Miniature Hanford pigs, producing imprints with distinct margins and indentations. Tissue samples were stored in 10% formalin after affixing an acrylic support ring with cyanoacrylate adhesive and sutures. Measurements of the six tooth mark analogues and cross-arch dimensions were taken at intervals of up to 38 days. Data from these measurements indicate a wide range of amount and type of distortion in preserved tissue. Although some samples were dimensionally stable, there was both contraction and expansion of bite mark specimens, even within individual skin samples. It appears that standard techniques for storage and preservation of bite mark samples will not produce reliable dimensional accuracy.