Perioperative considerations for adult patients with Dravet syndrome in regional centres.

Dravet syndrome (DS) is a rare and intractable severe form of epilepsy presenting in infancy with frequent prolonged myoclonic seizures and neurodevelopmental impairment, associated with a SCN1A gene mutation. Seizures are often triggered by temperature fluctuations and hyperthermia. This report presents a woman in her late adolescence with DS complicated with intractable catamenial epilepsy, a sex-specific form of epilepsy with seizure activity prominent during phases of the menstrual cycle. The patient underwent general anaesthesia for a hysteroscopy, cervical dilatation and endometrial curettage with Mirena insertion to improve seizure control. Her perioperative care was optimised for seizure prevention with continuation of antiepileptic medications, strict temperature monitoring and control, optimised anaesthetic agents encompassing induction with propofol and fentanyl with maintenance sevoflurane, followed by attentive postoperative care and monitoring. This case demonstrates that general anaesthesia can safely be delivered to adult patients with DS in rural and regional areas with thorough perioperative planning.

Immunogenomic Biomarkers and Validation in Lynch Syndrome.

Lynch syndrome (LS) is an inherited disorder in which affected individuals have a significantly higher-than-average risk of developing colorectal and non-colorectal cancers, often before the age of 50 years. In LS, mutations in DNA repair genes lead to a dysfunctional post-replication repair system. As a result, the unrepaired errors in coding regions of the genome produce novel proteins, called neoantigens. Neoantigens are recognised by the immune system as foreign and trigger an immune response. Due to the invasive nature of cancer screening tests, universal cancer screening guidelines unique for LS (primarily colonoscopy) are poorly adhered to by LS variant heterozygotes (LSVH). Currently, it is unclear whether immunogenomic components produced as a result of neoantigen formation can be used as novel biomarkers in LS. We hypothesise that: (i) LSVH produce measurable and dynamic immunogenomic components in blood, and (ii) these quantifiable immunogenomic components correlate with cancer onset and stage. Here, we discuss the feasibility to: (a) identify personalised novel immunogenomic biomarkers and (b) validate these biomarkers in various clinical scenarios in LSVH.

Genomic landscape of colorectal carcinoma in sub-Saharan Africa.

Our understanding of the molecular classification of colorectal carcinoma (CRC) has evolved significantly over the past two decades. Tumours can be broadly categorised as microsatellite stable (MSS), microsatellite instability (MSI) or CpG island-methylator phenotype. Prognostic and predictive information is provided by these categories. The overwhelming majority of the data on which these categories are based have originated from Europe and North America. There is a dearth of information represented from Africa and indigenous African patients. However, some small studies and preliminary data have shown significant differences in all of these groups. The prevalence of MSI in Africa is consistently reported as almost double that of European and North American data. Interestingly, BRAF V600E mutations and MLH1 promotor hypermethylation seem to be uncommon in Africa. The high proportion of MSI tumours is only partly accounted for by germline mutations in mismatch repair genes (Lynch syndrome), suggesting that there are likely to be other mechanisms at play. Within the MSS group, preliminary data suggest that the typical molecular pathways (Wingless/Integrated pathway activation) may not be as dominant in Africa. The purpose of this review is to summarise the current state of the molecular genetic landscape of CRC in Africa and provide insights into areas for further study.

Treatment of hepatocellular carcinoma in sub-Saharan Africa: challenges and solutions.

Most patients who develop hepatocellular carcinoma reside in resource-poor countries, a category that includes most countries in sub-Saharan Africa. Age-standardised incidence rates of hepatocellular carcinoma in western, central, eastern, and southern Africa is 6·53 per 100 000 inhabitants to 11·1 per 100 000 inhabitants. In high-income countries, around 40% of patients are diagnosed at an early stage, in which interventions with curative intent or palliative interventions are possible. By contrast, 95% of patients with hepatocellular carcinoma in sub-Saharan Africa present with advanced or terminal disease. In high-income countries, targets of 30-40% that have been set for intervention with curative intent are regularly met, with expected 5-year overall survival rates in the region of 70%. These outcomes are in sharp contrast with the very small proportion of patients in sub-Saharan Africa who are treated with curative intent. Primary prevention through the eradication and reduction of risk factors is still suboptimal because of logistical challenges. The challenges facing primary prevention, in combination with difficult-to-manage historic and emerging risk factors, such as ethanol overconsumption and metabolic dysfunction-associated liver disease, mandates secondary prevention for populations at risk through screening and surveillance. Although the increased treatment needs yielded by screening and surveillance in high-income countries are manageable by the incremental expansion of existing interventional resources, the lack of resources in sub-Saharan Africa will undermine the possible benefits of secondary prevention. An estimate of the projected effect of the introduction and expansion of screening and surveillance, resulting in stage migration and possibilities for active interventions for hepatocellular carcinoma, would facilitate optimal planning and development of resources.

A Scoring Model and Protocol to Adapt Universal Screening for Lynch Syndrome to Identify Germline Pathogenic Variants by Next Generation Sequencing from Colorectal Cancer Patients and Cascade Screening.

Identification of germline pathogenic variants (PV) predisposing to Lynch syndrome (LS) is an important step for effective use of cascade screening of extended at-risk lineages, leading to reduced morbidity and mortality due to colorectal cancer (CRC). As a general rule, however, next generation sequencing (NGS, either of gene panels or whole exomes) is relatively expensive and unaffordable for general clinical use. In resource-poor settings, performing NGS testing on an entire cohort of CRC patients, even if limited to those under 50 or 60 years of age, still places an enormous burden on limited resources. Although family history can be a good indicator for LS testing, identifying at-risk family members and offering cascade screening may not benefit many patients/probands without an obvious family history. This article presents a novel program called Modified Ascertainment and follow-up Program (MAP) with a scoring model for LS ascertainment and molecular screening by NGS with diagnosis confirmation of PV and cascade screening. The goal is to improve LS ascertainment in light of the growing burden of early-onset CRC, particularly in low- and middle-income countries. Through MAP, judiciously applied molecular genetics will improve identification of PV predisposing to LS and cascade screening.

Leading During a Pandemic: A School Nurse Administrator Roundtable.

The ongoing COVID-19 pandemic has been taxing to healthcare workers, no less for those serving on the front lines in schools. From initial school closures and online learning to gradual reopening with hybrid learning models, to full in-person learning, school nurse administrators provided guidance in collaboration with public health officials, based on evolving information. Infection control was at the forefront, while government and scientists partnered to quickly develop effective vaccines. Technology provided new virtual platforms for learning, conducting meetings, and socialization, while also being widely used to deliver information, misinformation, and disinformation. Challenges have been numerous, but school nurse administrators and school nurses in general, with a commitment to the health and safety of their populations, continue to adapt to the ever-changing demands. The journal's Editorial Advisory Board interviewed five school nurse administrators, representative of diverse geographic locations, school population size, and employer models, to capture their reflections on school health leadership during the COVID-19 pandemic. History is deserving of their stories.

Hepatitis B virus-associated hepatocellular carcinoma in South Africa in the era of HIV.

BACKGROUND: Patients co-infected with hepatitis B virus (HBV) and the human immunodeficiency virus (HIV) are at risk of developing hepatocellular carcinoma (HCC). In sub-Saharan Africa, the overlap between high HIV and HBV prevalence may increase the incidence of HCC. This study investigated the impact of HBV/HIV co-infection on age at presentation and survival of HCC. METHODS: Ethical approval was obtained to recruit, following informed written consent, patients diagnosed with HCC at oncology units at four South African hospitals. Between December 2012 and August 2015, patients newly diagnosed with HCC were recruited and provided demographic and clinical data and blood specimens. Patients were tested for HBV, hepatitis C virus (HCV) and HIV. Survival data was available for a subset of patients. RESULTS: Of 107 HCC cases, 83 (78%) were male. Median age was 46 years (range 18 to 90 years), 68/106 (64%) were HBsAg-positive, and 22/100 (22%) were HIV infected. Among HBV surface antigen (HBsAg)-positive HCC cases, 18/66 (27%) were HIV-infected compared to 3/34 (9%) among those that were HBsAg-negative (p = 0.04). A greater proportion of HBV/HIV co-infected cases were female than HBV mono-infected (6/18, 33% vs 6/47, 13%; p = 0.005). In addition, HBV/HIV co-infected females presented at a younger mean age (36.8 years) than HBV mono-infected women (50.5 years) (p = 0.09). Median survival was 82 days among the HIV-infected HCC patients compared to 181 days among those without HIV (p = 0.15). CONCLUSIONS: HCC is an important complication in the HIV/HBV infected patient. HIV-positive patients presented with HCC at a younger age than HIV-negative patients, this effect appears to be greater in women. These data provide more evidence supporting the call to address. HCC as a cause of morbidity and mortality in the HBV/HIV co-infected patient population. (281 words).

Food restriction reduces neurogenesis in the avian hippocampal formation.

The mammalian hippocampus is particularly vulnerable to chronic stress. Adult neurogenesis in the dentate gyrus is suppressed by chronic stress and by administration of glucocorticoid hormones. Post-natal and adult neurogenesis are present in the avian hippocampal formation as well, but much less is known about its sensitivity to chronic stressors. In this study, we investigate this question in a commercial bird model: the broiler breeder chicken. Commercial broiler breeders are food restricted during development to manipulate their growth curve and to avoid negative health outcomes, including obesity and poor reproductive performance. Beyond knowing that these chickens are healthier than fully-fed birds and that they have a high motivation to eat, little is known about how food restriction impacts the animals' physiology. Chickens were kept on a commercial food-restricted diet during the first 12 weeks of life, or released from this restriction by feeding them ad libitum from weeks 7-12 of life. To test the hypothesis that chronic food restriction decreases the production of new neurons (neurogenesis) in the hippocampal formation, the cell proliferation marker bromodeoxyuridine was injected one week prior to tissue collection. Corticosterone levels in blood plasma were elevated during food restriction, even though molecular markers of hypothalamic-pituitary-adrenal axis activation did not differ between the treatments. The density of new hippocampal neurons was significantly reduced in the food-restricted condition, as compared to chickens fed ad libitum, similar to findings in rats at a similar developmental stage. Food restriction did not affect hippocampal volume or the total number of neurons. These findings indicate that in birds, like in mammals, reduction in hippocampal neurogenesis is associated with chronically elevated corticosterone levels, and therefore potentially with chronic stress in general. This finding is consistent with the hypothesis that the response to stressors in the avian hippocampal formation is homologous to that of the mammalian hippocampus.

Patient and tumour characteristics as prognostic markers for oesophageal cancer: a retrospective analysis of a cohort of patients at Groote Schuur Hospital.

OBJECTIVES: In addition to the high incidence of squamous carcinoma of the oesophagus among South African men, the neoplasm is also characterized by an exceptionally latent course and poor prognosis. The aim of this study was to review a cohort of patients with carcinoma of the oesophagus presenting to the Groote Schuur Hospital, Cape Town and evaluate patient and tumour characteristics for their role as prognostic markers for survival. METHODS: Information on patients was extracted from a database established and maintained over a 30-year period. Information for the analysis included patient demographics, clinical symptoms at presentation, tumour characteristics and treatment decisions. Statistical analyses were performed using GraphPad Prism 5 applying chi-square and Kaplan-Meier tests. RESULTS: Data were available on 1868 patients. The majority of patients were Black African men and the predominant histology was squamous cell carcinoma. There were significant differences (P < 0.05) in the survival of patients with respect to race (P < 0.001), performance status (P < 0.001), weight loss (P = 0.001) and prior tuberculosis diagnosis (P = 0.007). Tumour characteristics that were significantly associated with survival were histological type, tumour size and site. Gender, prior cancer, smoking status and tumour-related pain did not show significant association with survival in patients with oesophageal cancer. Only 19.8% of the patients were candidates for potentially curative treatment. CONCLUSIONS: This analysis shows that there are prominent patient and tumour characteristics that are significantly associated with survival with respect to oesophageal carcinoma. The inclusion of these factors in the initial assessment of patients may assist with appropriate treatment decisions.

Implementing a community bullying awareness intervention in an adolescent psychiatric unit: a feasibility study.

PROBLEM: Adolescents with a mental health diagnosis are at risk of involvement in bullying. We tested the feasibility of a bullying awareness group intervention in an established inpatient psychiatric unit milieu. METHODS: Adolescents admitted to an urban inpatient adolescent psychiatric unit were eligible to attend two sequential 1-hour Bullying Awareness intervention group sessions. Data were collected before the first session (T1), post-both sessions (T2), and following discharge from the unit (T3). FINDINGS: A total of 65 adolescents were enrolled; most were female (66.2%), African-American (60%), and in grades 10 to 12 (57%). Intervention feasibility was achieved as >80% of participants completed all components of the intervention and 100% completed all study questionnaires at T1 and T2. Feasibility of the follow-up (T3) was not achieved. Bullying knowledge scores improved significantly from T1 to T2. CONCLUSIONS: The intervention is feasible to implement in an inpatient adolescent psychiatry unit and can improve adolescents' bullying knowledge.

Identification of small molecules that selectively inhibit diacylglycerol lipase-α activity.

Recent genetic evidence suggests that the diacylglycerol lipase (DAGL-α) isoform is the major biosynthetic enzyme for the most abundant endocannabinoid, 2-arachidonoyl-glycerol (2-AG), in the central nervous system. Revelation of its essential role in regulating retrograde synaptic plasticity and adult neurogenesis has made it an attractive therapeutic target. Therefore, it has become apparent that selective inhibition of DAGL-α enzyme activity with a small molecule could be a strategy for the development of novel therapies for the treatment of disease indications such as depression, anxiety, pain, and cognition. In this report, the authors present the identification of small-molecule inhibitor chemotypes of DAGL-α, which were selective (≥10-fold) against two other lipases, pancreatic lipase and monoacylglycerol lipase, via high-throughput screening of a diverse compound collection. Seven chemotypes of interest from a list of 185 structural clusters, which included 132 singletons, were initially selected for evaluation and characterization. Selection was based on potency, selectivity, and chemical tractability. One of the chemotypes, the glycine sulfonamide series, was prioritized as an initial lead for further medicinal chemistry optimization.

Discovery of a novel series of quinolone α7 nicotinic acetylcholine receptor agonists.

High throughput screening led to the identification of a novel series of quinolone α7 nicotinic acetylcholine receptor (nAChR) agonists. Optimization of an HTS hit (1) led to 4-phenyl-1-(quinuclidin-3-ylmethyl)quinolin-2(1H)-one, which was found to be potent and selective. Poor brain penetrance in this series was attributed to transporter-mediated efflux, which was in turn due to high pKa. A novel 4-fluoroquinuclidine significantly lowered the pKa of the quinuclidine moiety, reducing efflux as measured by a Caco-2 assay.

Distinct genetic association at the PLCE1 locus with oesophageal squamous cell carcinoma in the South African population.

Oesophageal squamous cell carcinoma (OSCC) has a high prevalence in the Black and Mixed Ancestry populations of South Africa. Recently, three genome-wide association studies in Chinese populations identified five new OSCC susceptibility loci, including variants at PLCE1, C20orf54, PDE4D, RUNX1 and UNC5CL, but their contribution to disease risk in other populations is unknown. In this study, we report testing variants from these five loci for association with OSCC in the South African Black (407 cases and 849 controls) and Mixed Ancestry (257 cases and 860 controls) populations. The RUNX1 variant rs2014300, which reduced risk in the Chinese population, was associated with an increased risk of OSCC in the Mixed Ancestry population [odds ratio (OR) = 1.33, 95% confidence interval (CI) = 1.09-1.63, P = 0.0055], and none of the five loci were associated in the Black population. Since PLCE1 variants increased the risk of OSCC in all three Chinese studies, this gene was investigated further by sequencing in 46 Black South Africans. This revealed 48 variants, 10 of which resulted in amino acid substitutions, and much lower linkage disequilibrium across the PLCE1 locus than in the Chinese population. We genotyped five PLCE1 variants in cases and controls, and found association of Arg548Leu (rs17417407) with a reduced risk of OSCC (OR = 0.74, 95% CI = 0.60-0.93, P = 0.008) in the Black population. These findings indicate several differences in the genetic contribution to OSCC between the South African and Chinese populations that may be related to differences in their genetic architecture.

Molecular characterization and identification of surrogate substrates for diacylglycerol lipase α.

Diacylglycerol lipase α is the key enzyme in the formation of the most prevalent endocannabinoid, 2-arachidonoylglycerol in the brain. In this study we identified the catalytic triad of diacylglycerol lipase α, consisting of serine 472, aspartate 524 and histidine 650. A truncated version of diacylglycerol lipase α, spanning residues 1-687 retains complete catalytic activity suggesting that the C-terminal domain is not required for catalysis. We also report the discovery and the characterization of fluorogenic and chromogenic substrates for diacylglycerol lipase α. Assays performed with these substrates demonstrate equipotent inhibition of diacylglycerol lipase α by tetrahydrolipastatin and RHC-20867 as compared to reactions performed with the native diacylglycerol substrate. Thus, confirming the utility of assays using these substrates for identification and kinetic characterization of inhibitors from pharmaceutical collections.

Specificity and functionality of microRNA inhibitors.

BACKGROUND: Micro(mi)RNAs regulate gene expression through translational attenuation and messenger (m)RNA degradation, and are associated with differentiation, homeostasis and disease. Natural miRNA target recognition is determined primarily by perfect complementarity in a seed region (nucleotide positions 2 to 7) with additional interactions contributing in a sequence- and target-specific manner. Synthetic miRNA target analogs, which are fully complementary, chemically modified oligonucleotides, have been used successfully to inhibit miRNA function. RESULTS: In this paper, we present a first systematic study to evaluate the effect of mismatches in the target site on synthetic inhibitor activity. Panels of miRNA inhibitors containing two-nucleotide mismatches across the target site were tested against three miRNAs (miR-21, miR-22 and miR-122). The results showed that the function of inhibitors vary as mismatch positions in the inhibitors change. CONCLUSIONS: The data indicate that features important for natural miRNA target recognition (such as seed region complementarity) are also important for inhibitor functionality. In addition, base pairing at a second, more 3' region appears to be equally important in determining the efficacy of synthetic inhibitors. Considering the importance of these inhibitor regions and the expression of closely related miRNA sequences will enable researchers to interpret results more accurately in future experiments.

Effect of complete maternal and littermate deprivation on morphine-induced Fos-immunoreactivity in the adult male rat brain.

Previous research has demonstrated that rats reared in isolation from their dam and littermates show altered behavioral responsiveness to both natural and drug-mediated rewards. This study examined the effects of complete maternal deprivation through the use of artificial rearing on neural activation after acute morphine exposure in adulthood. Male rats were either artificially reared (AR) or maternally reared (MR) from postnatal day 5 to 21. In adulthood (4 mo old), rats received a single injection of morphine sulfate (10 mg/kg) or equivolume saline 2 h before perfusion and brain extraction. Neural activation was quantified using Fos immunohistochemistry. Analyses of several brain regions revealed a consistent pattern of differences between AR and MR rats. Specifically, relative to MR rats, AR rats showed significantly greater morphine-induced Fos-immunoreactivity in brain regions associated with the mesocorticolimbic "reward" pathway. These results support the hypothesis that functional activity in reward neurocircuitry can be altered by early life experience.

Signal peptide peptidase and gamma-secretase share equivalent inhibitor binding pharmacology.

The enzyme gamma-secretase has long been considered a potential pharmaceutical target for Alzheimer disease. Presenilin (the catalytic subunit of gamma-secretase) and signal peptide peptidase (SPP) are related transmembrane aspartyl proteases that cleave transmembrane substrates. SPP and gamma-secretase are pharmacologically similar in that they are targeted by many of the same small molecules, including transition state analogs, non-transition state inhibitors, and amyloid beta-peptide modulators. One difference between presenilin and SPP is that the proteolytic activity of presenilin functions only within a multisubunit complex, whereas SPP requires no additional protein cofactors for activity. In this study, gamma-secretase inhibitor radioligands were used to evaluate SPP and gamma-secretase inhibitor binding pharmacology. We found that the SPP enzyme exhibited distinct binding sites for transition state analogs, non-transition state inhibitors, and the nonsteroidal anti-inflammatory drug sulindac sulfide, analogous to those reported previously for gamma-secretase. In the course of this study, cultured cells were found to contain an abundance of SPP binding activity, most likely contributed by several of the SPP family proteins. The number of SPP binding sites was in excess of gamma-secretase binding sites, making it essential to use selective radioligands for evaluation of gamma-secretase binding under these conditions. This study provides further support for the idea that SPP is a useful model of inhibitory mechanisms and structure in the SPP/presenilin protein family.

Discovery of (S)-2-((S)-2-(3,5-difluorophenyl)-2-hydroxyacetamido)-N-((S,Z)-3-methyl-4-oxo-4,5-dihydro-3H-benzo[d][1,2]diazepin-5-yl)propanamide (BMS-433796): a gamma-secretase inhibitor with Abeta lowering activity in a transgenic mouse model of Alzheimer's disease.

We report on the design of benzodiazepinones as peptidomimetics at the carboxy terminus of hydroxyamides. Structure-activity relationships of diazepinones were investigated and orally active gamma-secretase inhibitors were synthesized. Active metabolites contributing to Abeta reduction were identified by analysis of plasma samples from Tg2576 mice. In particular, (S)-2-((S)-2-(3,5-difluorophenyl)-2-hydroxyacetamido)-N-((S,Z)-3-methyl-4-oxo-4,5-dihydro-3H-benzo[d][1,2]diazepin-5-yl)propanamide (BMS-433796) was identified with an acceptable pharmacodynamic and pharmacokinetic profile. Chronic dosing of BMS-433796 in Tg2576 mice suggested a narrow therapeutic window and Notch-mediated toxicity at higher doses.