Rare variants in genes coding for components of the terminal pathway of the complement system in preeclampsia.

Preeclampsia is a common multifactorial disease of pregnancy. Dysregulation of the complement activation is among emerging candidates responsible for disease pathogenesis. In a targeted exomic sequencing study we identified 14 variants within nine genes coding for components of the membrane attack complex (MAC, C5b-9) that are associated with preeclampsia. We found two rare missense variants in the C5 gene that predispose to preeclampsia (rs200674959: I1296V, OR (CI95) = 24.13 (1.25-467.43), p-value = 0.01 and rs147430470: I330T, OR (CI95) = 22.75 (1.17-440.78), p-value = 0.01). In addition, one predisposing rare variant and one protective rare variant were discovered in C6 (rs41271067: D396G, OR (CI95) = 2.93 (1.18-7.10), p-value = 0.01 and rs114609505: T190I, 0.02 OR (CI95) = 0.47 (0.22-0.92), p-value = 0.02). The results suggest that variants in terminal complement pathway predispose to preeclampsia.

Identification of complement factor H variants that predispose to pre-eclampsia: A genetic and functional study.

OBJECTIVE: The objective of the study was to investigate the role of genetic variants in complement proteins in pre-eclampsia. DESIGN: In a case-control study involving 609 cases and 2092 controls, five rare variants in complement factor H (CFH) were identified in women with severe and complicated pre-eclampsia. No variants were identified in controls. SETTING: Pre-eclampsia is a leading cause of maternal and fetal morbidity and mortality. Immune maladaptation, in particular, complement activation that disrupts maternal-fetal tolerance leading to placental dysfunction and endothelial injury, has been proposed as a pathogenetic mechanism, but this remains unproven. POPULATION: We genotyped 609 pre-eclampsia cases and 2092 controls from FINNPEC and the national FINRISK cohorts. METHODS: Complement-based functional and structural assays were conducted in vitro to define the significance of these five missense variants and each compared with wild type. MAIN OUTCOME MEASURES: Secretion, expression and ability to regulate complement activation were assessed for factor H proteins harbouring the mutations. RESULTS: We identified five heterozygous rare variants in complement factor H (L3V, R127H, R166Q, C1077S and N1176K) in seven women with severe pre-eclampsia. These variants were not identified in controls. Variants C1077S and N1176K were novel. Antigenic, functional and structural analyses established that four (R127H, R166Q, C1077S and N1176K) were deleterious. Variants R127H and C1077S were synthesised, but not secreted. Variants R166Q and N1176K were secreted normally but showed reduced binding to C3b and consequently defective complement regulatory activity. No defect was identified for L3V. CONCLUSIONS: These results suggest that complement dysregulation due to mutations in complement factor H is among the pathophysiological mechanisms underlying severe pre-eclampsia.

Introduction of surgical site surveillance post transrectal ultrasound (TRUS) guided prostate biopsy and the impact on infection rates.

Background: Transrectal ultrasound (TRUS)-guided prostate biopsy is associated with infection rates between 0.3 % and 3.2%. Infectious complications include urinary tract infection, prostatitis, bacteraemia and sepsis. Surgical site surveillance in this patient cohort is becoming increasingly important given global increases in antimicrobial resistance. Methods: Surgical site surveillance for patients undergoing TRUS biopsies was introduced in our hospital in 2017. All patients had a risk assessment form completed to assess for carriage or risk of carriage of multi-drug resistant organisms. An intense analysis was completed on any patient who developed an infection post-TRUS biopsy. Data was fed back on a quarterly basis to a multi-disciplinary working group. Members of this group include a Consultant Microbiologist, Infection Prevention and Control Nurse, Consultant Urologist, Antimicrobial Pharmacists and Clinical Nurse Ward Managers. Results: 784 TRUS-guided biopsy of the prostate procedures were performed between January 1 st 2017 and the end of the third quarter, 2021. The rate of infection post-TRUS was 2.7% in 2017, 3.4% in 2018 and 3.2% in 2019. This improved to 0% in 2020 and 0.8% in the first three quarters of 2021. Conclusions: Several interventions were introduced resulting in a sustained reduction in infection rates in this cohort. These include changing the choice of surgical antibiotic prophylaxis, improvement in the timing of antibiotic prophylaxis and scheduling of other urology procedures. The introduction of surgical site surveillance and multi-disciplinary input has demonstrated a reduction in infection rates post TRUS biopsy.

Burden of unique and low prevalence somatic mutations correlates with cancer survival.

Tumor mutational burden correlates with improved survival and immunotherapy response in some malignancies, and with tumor aggressiveness in others. To study the link between mutational burden and survival, we analyzed survival effects of tumor exonic missense mutation burden (TEMMB) across 6947 specimens spanning 31 cancers which have undergone whole exome sequencing as part of TCGA. We adjusted TEMMB for age, sex, stage, and recruitment center, and computed Cox-proportional models of TEMMB survival effects. We assigned a recurrence score (RS) to each cohort, defining RS as the burden of recurrent mutations exceeding 1% population prevalence. High TEMMB was associated with improved survival in cutaneous melanoma: hazard ratio (HR) = 0.71 [0.60-0.85], p = 0.0002, urothelial bladder carcinoma: HR = 0.74 [0.59-0.93], p = 0.01, and ovarian carcinoma: HR = 0.80 [0.70-0.93], p = 0.003. High TEMMB was associated with decreased survival in colorectal adenocarcinoma: HR = 1.32 [1.00-1.74], p < 0.05. We identified that TEMMB survival effects were governed by the balance of recurrent and non-recurrent mutations. In cancers with a low RS, high TEMMB was correlated with better survival outcomes (r = 0.49, p = 0.02). In conclusion, TEMMB effects on survival depend on recurrent mutation enrichment; tumor types that are highly enriched in passenger mutations show a survival benefit in the setting of high tumor mutational burden.

Base-specific mutational intolerance near splice sites clarifies the role of nonessential splice nucleotides.

Variation in RNA splicing (i.e., alternative splicing) plays an important role in many diseases. Variants near 5' and 3' splice sites often affect splicing, but the effects of these variants on splicing and disease have not been fully characterized beyond the two "essential" splice nucleotides flanking each exon. Here we provide quantitative measurements of tolerance to mutational disruptions by position and reference allele-alternative allele combinations. We show that certain reference alleles are particularly sensitive to mutations, regardless of the alternative alleles into which they are mutated. Using public RNA-seq data, we demonstrate that individuals carrying such variants have significantly lower levels of the correctly spliced transcript, compared to individuals without them, and confirm that these specific substitutions are highly enriched for known Mendelian mutations. Our results propose a more refined definition of the "splice region" and offer a new way to prioritize and provide functional interpretation of variants identified in diagnostic sequencing and association studies.

Protective Low-Frequency Variants for Preeclampsia in the Fms Related Tyrosine Kinase 1 Gene in the Finnish Population.

Preeclampsia is a common pregnancy-specific vascular disorder characterized by new-onset hypertension and proteinuria during the second half of pregnancy. Predisposition to preeclampsia is in part heritable. It is associated with an increased risk of cardiovascular disease later in life. We have sequenced 124 candidate genes implicated in preeclampsia to pinpoint genetic variants contributing to predisposition to or protection from preeclampsia. First, targeted exomic sequencing was performed in 500 preeclamptic women and 190 controls from the FINNPEC cohort (Finnish Genetics of Preeclampsia Consortium). Then 122 women with a history of preeclampsia and 1905 parous women with no such history from the National FINRISK Study (a large Finnish population survey on risk factors of chronic, noncommunicable diseases) were included in the analyses. We tested 146 rare and low-frequency variants and found an excess (observed 13 versus expected 7.3) nominally associated with preeclampsia (P<0.05). The most significantly associated sequence variants were protective variants rs35832528 (E982A; P=2.49E-4; odds ratio=0.387) and rs141440705 (R54S; P=0.003; odds ratio=0.442) in Fms related tyrosine kinase 1. These variants are enriched in the Finnish population with minor allele frequencies 0.026 and 0.017, respectively. They may also be associated with a lower risk of heart failure in 11 257 FINRISK women. This study provides the first evidence of maternal protective genetic variants in preeclampsia.

Finding the red flags: Swallowing difficulties after cardiac surgery in patients with prolonged intubation.

PURPOSE: This retrospective audit set out to identify referral rates, swallowing characteristics, and risk factors for dysphagia and silent aspiration in at-risk patients after cardiac surgery. Dysphagia and silent aspiration are associated with poorer outcomes post cardiac surgery. METHODS: One hundred ninety patients who survived cardiac surgery and received more than 48 hours of intubation were included. Preoperative, perioperative, and postoperative information was collected. RESULTS: Forty-one patients (22%) were referred to speech-language pathology for a swallowing assessment. Twenty-four of these patients (13%) underwent instrumental swallowing assessment, and silent aspiration was observed in 17 (70% of patients diagnosed as having dysphagia via instrumental assessment). Multilogistic analysis revealed previous stroke (P < .05), postoperative stroke (P < .001), and tracheostomy (P < .001) independently associated with dysphagia. The odds ratio for being diagnosed as having pneumonia, if a patient was diagnosed as having dysphagia, was 3.3. CONCLUSIONS: Patients identified with dysphagia after cardiac surgery had a high incidence of silent aspiration and increased risk of pneumonia. However, referral rates were low in this at-risk patient group. Early identification and ongoing assessment and appropriate management of dysphagic patients by a speech-language pathologist are strongly recommended.

Restraint stress-induced brain activation patterns in two strains of mice differing in their anxiety behaviour.

Genetically identical inbred mouse strains are one of the most useful tools in dissecting the genetic basis of complex disorders. C57BL/6 and BALB/c mice differ markedly in emotionality. In particular, BALB/c mice are more stress-sensitive and have been proposed to be a model of pathological anxiety. There is a paucity of studies investigating whether brain activation in response to a stressor is different in these two strains. To this end, having confirmed that the strains differ in anxiety responses in a light-dark box test, we then examined if restraint stress induced increases in c-Fos protein expression in selective regions of the mouse brain. The areas of interest analysed were the paraventricular nucleus (PVN) of the hypothalamus, prefrontal cortex (PFC), the paraventricular thalamic nucleus (PV) and the hippocampus. These areas were chosen due to their known involvement in stress response. Our data demonstrate that BALB/c showed a similar cellular activation pattern to stress, with respect to c-Fos expression, in the PVN, PV and in the hippocampus. On the other hand, BALB/c showed markedly blunted stress-induced brain activation compared with stressed C57BL/6 mice in both the CG1 and CG2 regions of the PFC. The lower levels of stress-induced activity in high anxiety BALB/c mice, possibly indicate a circuit dysregulation at the cortico-limbic level in response to stress.

Microgels: From responsive polymer colloids to biomaterials.

Microgels are network polymer colloid particles that can swell in a good solvent or as a result of electrostatic repulsion between charged groups produced by pH-triggered neutralisation. They have attracted considerable interest as both model colloids and for their potential applications. This discussion reviews the properties of microgel particles and the current understanding of their structure. The review concentrates on the period after an earlier microgel review by Saunders and Vincent [Adv. Coll. Interf. Sci., 1999, 80, 1]. A key challenge for microgel research has involved elucidation of the internal particle structure. Most microgels prepared by emulsion or precipitation polymerisation have a core-shell structure. The segment density is usually highest in the core. Here, we discuss relationships between microgel structure and dispersion stability. The reasons for the exceptional stability of microgel dispersions are considered. There are a number of favourable structural features that make microgels candidates for biomaterial applications and these are discussed. The main potential biomaterial applications that have been investigated for microgels to date are drug delivery and regenerative medicine. Poly(NIPAM) (N-isopropylacrylamide) microgels have been extensively studied in the context of drug delivery. Regenerative medicine research for microgels is an emerging area. Recent work involving the use of gelled microgel dispersions to support biomechanically meaningful loads is considered. We conclude with a discussion of promising directions for microgel research as biomaterials.

Sexually dimorphic effects of maternal separation stress on corticotrophin-releasing factor and vasopressin systems in the adult rat brain.

Neonatal maternal separation has been widely used to model the well-established causal relationship between stress in early life and the later development of depression. As corticotrophin-releasing factor (CRF) and vasopressin (AVP) have been implicated in depression, we aimed to determine the long-term effects of maternal separation stress on these neuropeptide systems, and also to explore whether these effects are gender-dependent. Immunohistochemical staining of CRF, AVP and c-Fos was used to assess whether these neuropeptide systems were affected following an acute swim stress in male and female maternally separated rats. There was an increase in CRF-immunoreactivity (IR) (p<0.05), and an increased co-localisation of c-Fos and CRF (p<0.05) following stress, in the paraventricular nucleus of the hypothalamus (PVN) of maternally separated female rats only. We found no differences in CRF in the hypothalamus of maternally separated and control male rats. However, male maternally separated rats exhibited decreases in AVP-IR in both the non-stressed and stressed groups relative to controls (p<0.001). These data provide further evidence of the involvement of the neuropeptides CRF and AVP in the long-term maladaptive effects of maternal separation stress in early life. The enhanced CRF response to stress in MS females relative to males suggests that maternal separation stress results in a more reactive neuroendocrinological stress system in females, than in males. Furthermore, the sexually dimorphic effects of maternal separation on these neuropeptides indicate that gender is an important factor influencing the trajectory of early life stress effects on CRF and AVP systems in the brain.