Molecular genetic analysis of candidate genes for glutaric aciduria type II in a cohort of patients from Queensland, Australia.

Glutaric aciduria type II (GAII) is a heterogeneous genetic disorder affecting mitochondrial fatty acid, amino acid and choline oxidation. Clinical manifestations vary across the lifespan and onset may occur at any time from the early neonatal period to advanced adulthood. Historically, some patients, in particular those with late onset disease, have experienced significant benefit from riboflavin supplementation. GAII has been considered an autosomal recessive condition caused by pathogenic variants in the gene encoding electron-transfer flavoprotein ubiquinone-oxidoreductase (ETFDH) or in the genes encoding electron-transfer flavoprotein subunits A and B (ETFA and ETFB respectively). Variants in genes involved in riboflavin metabolism have also been reported. However, in some patients, molecular analysis has failed to reveal diagnostic molecular results. In this study, we report the outcome of molecular analysis in 28 Australian patients across the lifespan, 10 paediatric and 18 adult, who had a diagnosis of glutaric aciduria type II based on both clinical and biochemical parameters. Whole genome sequencing was performed on 26 of the patients and two neonatal onset patients had targeted sequencing of candidate genes. The two patients who had targeted sequencing had biallelic pathogenic variants (in ETFA and ETFDH). None of the 26 patients whose whole genome was sequenced had biallelic variants in any of the primary candidate genes. Interestingly, nine of these patients (34.6%) had a monoallelic pathogenic or likely pathogenic variant in a single primary candidate gene and one patient (3.9%) had a monoallelic pathogenic or likely pathogenic variant in two separate genes within the same pathway. The frequencies of the damaging variants within ETFDH and FAD transporter gene SLC25A32 were significantly higher than expected when compared to the corresponding allele frequencies in the general population. The remaining 16 patients (61.5%) had no pathogenic or likely pathogenic variants in the candidate genes. Ten (56%) of the 18 adult patients were taking the selective serotonin reuptake inhibitor antidepressant sertraline, which has been shown to produce a GAII phenotype, and another two adults (11%) were taking a serotonin-norepinephrine reuptake inhibitor antidepressant, venlafaxine or duloxetine, which have a mechanism of action overlapping that of sertraline. Riboflavin deficiency can also mimic both the clinical and biochemical phenotype of GAII. Several patients on these antidepressants showed an initial response to riboflavin but then that response waned. These results suggest that the GAII phenotype can result from a complex interaction between monoallelic variants and the cellular environment. Whole genome or targeted gene panel analysis may not provide a clear molecular diagnosis.

Germline pathogenic SMARCA4 variants in neuroblastoma.

Heterozygous germline pathogenic variants (GPVs) in SMARCA4, the gene encoding the ATP-dependent chromatin remodelling protein SMARCA4 (previously known as BRG1), predispose to several rare tumour types, including small cell carcinoma of the ovary, hypercalcaemic type, atypical teratoid and malignant rhabdoid tumour, and uterine sarcoma. The increase in germline testing of SMARCA4 in recent years has revealed putative GPVs affecting SMARCA4 in patients with other cancer types. Here we describe 11 patients with neuroblastoma (NBL), including 4 previously unreported cases, all of whom were found to harbour heterozygous germline variants in SMARCA4 Median age at diagnosis was 5 years (range 2 months-26 years); nine were male; and eight of nine cases had tumour location information in the adrenal gland. Eight of the germline variants were expected to result in loss of function of SMARCA4 (large deletion, truncating and canonical splice variants), while the remaining four were missense variants. Loss of heterozygosity of the wild-type SMARCA4 allele was found in all eight cases where somatic testing was performed, supporting the notion that SMARCA4 functions as a classic tumour suppressor. Altogether, these findings strongly suggest that NBL should be included in the spectrum of SMARCA4-associated tumours.

RIvER Clinic: Rethinking Incarceration and Empowering Recovery-An Innovative Postincarceration Care Delivery Model Implemented During the COVID-19 Pandemic.

The Rethinking Incarceration and Empowering Recovery (RIvER) Clinic was launched in June 2021 to address the health disparities experienced during and after incarceration. The RIvER Clinic's multidisciplinary, community-centered team engages patients during jail detention and after release via telehealth, collocated in community locations, on a mobile van, and in clinic. The clinic serves as a bridge between incarceration and the establishment of permanent health care and social services in the community. In 2022, a total of 479 visits were completed. The clinic provided multidisciplinary substance use support to all eligible patients, paying for 104 medication for opioid use disorder (MOUD) prescriptions for uninsured patients. Twenty-five percent of patients were transitioned to community-based care, and less than 5% of patients were reincarcerated. Despite some limitations, results demonstrate that the RIvER Clinic is successfully reintegrating a marginalized population into its community. The purpose of this article is to describe the implementation and preliminary outcomes of this postincarceration clinic.

Bi-allelic loss-of-function OBSCN variants predispose individuals to severe recurrent rhabdomyolysis.

Rhabdomyolysis is the acute breakdown of skeletal myofibres in response to an initiating factor, most commonly toxins and over exertion. A variety of genetic disorders predispose to rhabdomyolysis through different pathogenic mechanisms, particularly in patients with recurrent episodes. However, most cases remain without a genetic diagnosis. Here we present six patients who presented with severe and recurrent rhabdomyolysis, usually with onset in the teenage years; other features included a history of myalgia and muscle cramps. We identified 10 bi-allelic loss-of-function variants in the gene encoding obscurin (OBSCN) predisposing individuals to recurrent rhabdomyolysis. We show reduced expression of OBSCN and loss of obscurin protein in patient muscle. Obscurin is proposed to be involved in sarcoplasmic reticulum function and Ca2+ handling. Patient cultured myoblasts appear more susceptible to starvation as evidenced by a greater decreased in sarcoplasmic reticulum Ca2+ content compared to control myoblasts. This likely reflects a lower efficiency when pumping Ca2+ back into the sarcoplasmic reticulum and/or a decrease in Ca2+ sarcoplasmic reticulum storage ability when metabolism is diminished. OSBCN variants have previously been associated with cardiomyopathies. None of the patients presented with a cardiomyopathy and cardiac examinations were normal in all cases in which cardiac function was assessed. There was also no history of cardiomyopathy in first degree relatives, in particular in any of the carrier parents. This cohort is relatively young, thus follow-up studies and the identification of additional cases with bi-allelic null OBSCN variants will further delineate OBSCN-related disease and the clinical course of disease.

Ependymoma-like tumor with mesenchymal differentiation (ELTMD) with ZFTA:NCOA1 fusion: A diagnostic challenge.

Ependymal tumors are classified based on their location, histology, and molecular characteristics. Supratentorial ependymomas (ST-EPNs) are a group of circumscribed supratentorial gliomas, which usually have pathogenic fusions involving either zinc finger translocation associated (ZFTA) (formerly C11orf95) or YAP1. A subtype of ependymoma was recently described and labeled ependymoma-like tumors with mesenchymal differentiation (ELTMDs). We describe a case of a 5-year-old boy who presented with a right frontal tumor. The diagnosis was challenging, and a correct diagnosis could only be reached after reanalysis of methylation data with a more recent version of the classifier and RNA fusion testing, which revealed ZFTA:NCOA1 (nuclear receptor coactivator 1) fusion. There are only a handful of cases of this entity, which is being reported for its rarity and the diagnostic challenge it poses.

Fatal granulomatous amebic encephalitis initially presenting with a cutaneous lesion.

We present a case of a 66-year-old man with a cutaneous Balamuthia mandrillaris lesion that progressed to fatal granulomatous amoebic encephalitis. We provide a summary of Australian cases and describe the clinical features and approach to diagnosing this rare but devastating condition, including the importance of PCR for diagnosis.

Change in CT-measured acetabular bone density following total hip arthroplasty: a systematic review and meta-analysis.

BACKGROUND AND PURPOSE: Assessing peri-acetabular bone quality is valuable for optimizing the outcomes of primary total hip arthroplasty (THA) as preservation of good quality bone stock likely affects implant stability. The aim of this study was to perform a meta-analysis of peri-acetabular bone mineral density (BMD) changes over time measured using quantitative computer tomography (CT) and, second, to investigate the influence of age, sex, and fixation on the change in BMD over time. METHODS: A systematic search of Embase, Scopus, Web of Science, and PubMed databases identified 19 studies that measured BMD using CT following THA. The regions of interest (ROI), reporting of BMD results, and scan protocols were extracted. A meta-analysis of BMD was performed on 12 studies that reported measurements immediately postoperatively and at follow-up. RESULTS: The meta-analysis determined that periacetabular BMD around both cemented and uncemented components decreases over time. The amount of BMD loss increased relative to proximity of the acetabular component. There was a greater decrease in cortical BMD over time in females and cancellous BMD for young patients of any sex. CONCLUSION: Peri-acetabular BMD decreases at different rates relative to its proximity to the acetabular component. Cancellous BMD decreases more in young patients and cortical bone decreases more in females. Standardized reporting parameters and suggested ROI to measure peri-acetabular BMD are proposed, to enable comparison between implant and patient variables in the future.

Elements Influencing Recruitment and Retention of Millennial Hospitalists Born in or after 1982: a Survey-Based Study.

BACKGROUND: Hospitalist turnover is exceedingly high, placing financial burdens on hospital medicine groups (HMGs). Following training, many begin their employment in medicine as early-career hospitalists, the majority being millennials. OBJECTIVE: To understand what elements influence millennial hospitalists' recruitment and retention. DESIGN: We developed a survey that asked participants to rate the level of importance of 18 elements (4-point Likert scale) in their decision to choose or remain at an HMG. PARTICIPANTS: The survey was electronically distributed to hospitalists born in or after 1982 across 7 HMGs in the USA. MAIN MEASURES: Elements were grouped into four major categories: culture of practice, work-life balance, financial considerations, and career advancement. We calculated the means for all 18 elements reported as important across the sample. We then calculated means by averaging elements within each category. We used unpaired t-tests to compare differences in means for categories for choosing vs. remaining at an HMG. KEY RESULTS: One hundred forty-four of 235 hospitalists (61%) responded to the survey. 49.6% were females. Culture of practice category was the most frequently rated as important for choosing (mean 96%, SD 12%) and remaining (mean 96%, SD 13%) at an HMG. The category least frequently rated as important for both choosing (mean 69%, SD 35%) and remaining (mean 76%, SD 32%) at an HMG was career advancement. There were no significant differences between respondent gender, race, or parental status and ratings of elements for choosing or remaining with HMGs. CONCLUSION: Culture of practice at an HMG may be highly important in influencing millennial hospitalists' decision to choose and stay at an HMG. HMGs can implement strategies to create a millennial-friendly culture which may help improve recruitment and retention.

Rapid SABRE Catalyst Scavenging Using Functionalized Silicas.

In recent years the NMR hyperpolarisation method signal amplification by reversible exchange (SABRE) has been applied to multiple substrates of potential interest for in vivo investigation. Unfortunately, SABRE commonly requires an iridium-containing catalyst that is unsuitable for biomedical applications. This report utilizes inductively coupled plasma-optical emission spectroscopy (ICP-OES) to investigate the potential use of metal scavengers to remove the iridium catalytic species from the solution. The most sensitive iridium emission line at 224.268 nm was used in the analysis. We report the effects of varying functionality, chain length, and scavenger support identity on iridium scavenging efficiency. The impact of varying the quantity of scavenger utilized is reported for the three scavengers with the highest iridium removed from initial investigations: 3-aminopropyl (S1), 3-(imidazole-1-yl)propyl (S4), and 2-(2-pyridyl) (S5) functionalized silica gels. Exposure of an activated SABRE sample (1.6 mg mL-1 of iridium catalyst) to 10 mg of the most promising scavenger (S5) resulted in <1 ppm of iridium being detectable by ICP-OES after 2 min of exposure. We propose that combining the approach described herein with other recently reported approaches, such as catalyst separated-SABRE (CASH-SABRE), would enable the rapid preparation of a biocompatible SABRE hyperpolarized bolus.

Cerebral amyloid angiopathy with related inflammation masquerading as crescendo transient ischaemic attacks.

Cerebral amyloid angiopathy with related inflammation (CAA-RI) is an uncommon inflammatory subtype of CAA, with a variety of presentations that can mimic other focal and diffuse neurological disorders. We present a 63-year-old man with recurrent stereotyped focal neurological symptoms, who was initially diagnosed as capsular warning syndrome and treated with antithrombotic therapy. Atypical imaging led to further investigation including a cerebral biopsy, which confirmed CAA-RI; he improved clinically and radiologically with immunosuppression. This case highlights how CAA-RI is often under-recognised and that patients risk receiving inappropriate anticoagulation and delay in starting immunosuppression.

NFIA and NFIB function as tumour suppressors in high-grade glioma in mice.

Nuclear factor one (NFI) transcription factors are implicated in both brain development and cancer in mice and humans and play an essential role in glial differentiation. NFI expression is reduced in human astrocytoma samples, particularly those of higher grade, whereas over-expression of NFI protein can induce the differentiation of glioblastoma cells within human tumour xenografts and in glioblastoma cell lines in vitro. These data indicate that NFI proteins may act as tumour suppressors in glioma. To test this hypothesis, we generated complex mouse genetic crosses involving six alleles to target gene deletion of known tumour suppressor genes that induce endogenous high-grade glioma in mice, and overlaid this with loss of function Nfi mutant alleles, Nfia and Nfib, a reporter transgene and an inducible Cre allele. Deletion of Nfi resulted in reduced survival time of the mice, increased tumour load and a more aggressive tumour phenotype than observed in glioma mice with normal expression of NFI. Together, these data indicate that NFI genes represent a credible target for both diagnostic analyses and therapeutic strategies to combat high-grade glioma.

Hyperpolarisation of Mirfentanil by SABRE in the Presence of Heroin.

Mirfentanil, a fentanyl derivative that is a µ-opioid partial agonist, is hyperpolarised via Signal Amplification By Reversible Exchange (SABRE), a para-hydrogen-based technique. [Ir(IMes)(COD)Cl] (IMes=1,3-bis(2,4,6-trimethylphenyl)imidazole-2-ylidene, COD=cyclooctadiene) was employed as the polarisation transfer catalyst. Following polarisation transfer at 6.5 mT, the pyrazine-protons were enhanced by 78-fold (polarisation, P=0.04 %). The complex [Ir(IMes)(H)2 (mirfentanil)2 (MeOH)]+ is proposed to form based on the observation of two hydrides at δ -22.9 (trans to mirfentanil) and -24.7 (trans to methanol). In a mixture of mirfentanil and heroin, the former could be detected using SABRE at concentrations less than 1 % w/w. At the lowest concentration analyzed, the amount of mirfentanil present was 0.18 mg (812 µM) and produced a signal enhancement of -867-fold (P=0.42 %). following polarisation transfer at 6.5 mT.

Growth of Intramedullary Spinal Cord Dermoid Cyst from a Congenital Thoracic Dermal Sinus Tract after Negative Screening Ultrasound Imaging.

INTRODUCTION: Intramedullary thoracic dermoid cysts are rare lesions that are associated with dermal sinus tracts (DSTs). Current recommendations advocate for imaging-based screening of suspected DSTs shortly after birth to exclude associated inclusion lesions. CASE PRESENTATION: A 6-year-old male child presented with a 2-week history of progressive ataxia, lower limb weakness, and hyperreflexia. He was suspected to have a thoracic DST at birth, though initial screening ultrasound was negative for an inclusion lesion or intradural tract. On representation, MRI demonstrated a 3.9-cm intramedullary thoracic dermoid cyst causing significant spinal cord compression. Intraoperatively, a DST extending intradurally was found. The associated dermoid cyst was removed via intracapsular resection. CONCLUSIONS: Whilst dermoid cysts are presumed to progressively develop from DSTs, to our knowledge, this is the first case in English literature documenting a thoracic spinal cord intramedullary dermoid cyst following a negative screening ultrasound for a suspected DST. We use this case to highlight the false-negative rates associated with postnatal screening and advocate for early neurosurgical referral of suspected DSTs, regardless of imaging findings.

An evaluation of strategies for restoring a degraded New Zealand scallop fishery using stochastic dynamic simulation modelling.

A decision-theoretical approach was used to evaluate strategies to rebuild a severely depleted scallop (Pecten novaezelandiae) populations in the Tasman Bay and Golden Bay of New Zealand. These strategies were: no intervention, cessation of seabed bottom contact fishing, and reduction of sediment and nutrient runoff from surrounding land through on-farm practices. Our approach combined outputs of estimated effects of on-farm practices on erosion and nutrient reduction with a stochastic dynamic model of the scallop populations. The most effective individual intervention is eliminating bottom contact fishing through dredging and trawling which increased scallop biomass on average by 73% compared to the no intervention scenario. Although on-farm practices have reduced sedimentation and nutrient runoff significantly (28-36% and 2%, respectively), they have no effect on scallop biomass if implemented individually and led to only marginal improvements in scallop biomass if implemented alongside cessation of bottom contact fishing (2-4%). Although our results showed, on average, substantial recovery in the scallop population when reducing seabed bottom contact and water pollution, the large uncertainty boundaries makes it unclear whether these improvements would be realized. The long-term success of such strategies will depend on the available habitat being able to sustain high densities of healthy scallop adults and recruits, a situation that has been posited in our analysis. Where scallop juvenile survival is compromised by sedimentation, nutrient pollution, or other exogenous influences, proposed interventions may be insufficient to aid recovery.

Benchtop NMR analysis of piperazine-based drugs hyperpolarised by SABRE.

Piperazine-based drugs, such as N-benzylpiperazine (BZP), became attractive in the 2000s due to possessing effects similar to amphetamines. Herein, BZP, in addition to its pyridyl analogues, 2-, 3-, and 4-pyridylmethylpiperidine (2-PMP, 3-PMP, and 4-PMP respectively) was subjected to the hyperpolarisation technique Signal Amplification By Reversible Exchange (SABRE) in order to demonstrate the use of this technique to detect these piperazine-based drugs. Although BZP was not hyperpolarised via SABRE, 2-PMP, 3-PMP, and 4-PMP were, with the ortho- and meta-pyridyl protons of 4-PMP showing the largest enhancement of 313-fold and 267-fold, respectively, in a 1.4-T detection field, following polarisation transfer at Earth's magnetic field. In addition to the freebase, 4-PMP.3HCl was also appraised by SABRE and was found not to polarise, however, the addition of increasing equivalents of triethylamine (TEA) produced the freebase, with a maximum enhancement observed upon the addition of 3 equivalents of TEA. Further addition of TEA led to a reduction in the observed enhancement. SABRE was also employed to polarise 4-PMP.3HCl (~20% w/w) in a simulated tablet to demonstrate the forensic application of the technique (138-fold enhancement for the ortho-pyridyl protons). The amount of 4-PMP.3HCl present in the simulated tablet was quantified via NMR using D2 O as a solvent and compared well to complimentary gas chromatography-mass spectrometry data. Exchanging D2 O for CD3 OD as the solvent utilised for analysis resulted in a significantly lower amount of 4-PMP.3HCl being determined, thus highlighting safeguarding issues linked to drug abuse in relation to determining the amount of active pharmaceutical ingredient present.

Highly Porous Tantalum Acetabular Components Without Ancillary Screws Have Similar Migration to Porous Titanium Acetabular Components With Screws at 2 Years: A Randomized Controlled Trial.

BACKGROUND: It is proposed that highly porous coatings on acetabular components, such as a porous tantalum coating, provide adequate fixation without ancillary screw fixation in primary total hip arthroplasty (THA). However, tantalum acetabular components have been associated with higher rates of revision than other uncemented components in national registries. The aim of this randomized controlled trial is to determine whether the early migration of a solid-backed tantalum acetabular component was no greater than that of a titanium acetabular component with ancillary screw fixation that has proven good clinical results. METHODS: Sixty-six patients aged 40 to 64 years, with osteoarthritis and Charnley grade A or B activity grade and who underwent primary THA, were recruited into the trial. Patients were randomized intraoperatively to receive either the tantalum or titanium acetabular component. All patients received the same cemented polished tapered femoral stem, 28-mm cobalt-chromium femoral head, and highly cross-linked polyethylene liner. Acetabular component migration was measured using radiostereometric analysis at 4-6 days postoperatively and at 6 weeks, 3 months, 1 and 2 years following THA. RESULTS: The mean proximal migration at 2 years for the tantalum cohort was 0.17 mm (95% confidence interval, 0.09-0.24) which was no greater than that of the titanium cohort which was 0.19 mm (0.07-0.32). Harris hip scores and functional activity scores were similar between groups. CONCLUSION: These results demonstrate that early stability can be achieved without ancillary screw fixation through the use of a highly porous high friction coating on a solid-backed modular acetabular component. LEVEL OF EVIDENCE: Level I.

The dystroglycan receptor maintains glioma stem cells in the vascular niche.

Glioblastomas (GBMs) are malignant central nervous system (CNS) neoplasms with a very poor prognosis. They display cellular hierarchies containing self-renewing tumourigenic glioma stem cells (GSCs) in a complex heterogeneous microenvironment. One proposed GSC niche is the extracellular matrix (ECM)-rich perivascular bed of the tumour. Here, we report that the ECM binding dystroglycan (DG) receptor is expressed and functionally glycosylated on GSCs residing in the perivascular niche. Glycosylated αDG is highly expressed and functional on the most aggressive mesenchymal-like (MES-like) GBM tumour compartment. Furthermore, we found that DG acts to maintain an MES-like state via tight control of MAPK activation. Antibody-based blockade of αDG induces robust ERK-mediated differentiation leading to reduced GSC potential. DG was shown to be required for tumour initiation in MES-like GBM, with constitutive loss significantly delaying or preventing tumourigenic potential in-vivo. These findings reveal a central role of the DG receptor, not only as a structural element, but also as a critical factor promoting MES-like GBM and the maintenance of GSCs residing in the perivascular niche.

A case of immune-mediated encephalitis related to daclizumab therapy.

This report will detail a case of immune-mediated encephalitis in the context of daclizumab therapy. Daclizumab is a humanised monoclonal antibody which, prior to its recent worldwide withdrawal due to safety concerns, was utilised as a disease-modifying therapy in relapsing-remitting multiple sclerosis. The withdrawal of this therapy was prompted by concerns over 12 cases of serious immune-mediated adverse reactions in the central nervous system. We report an additional case, including clinical data and results of neuroimaging, cerebrospinal fluid (CSF) examination and brain biopsy.

Transversus abdominis block utilizing liposomal bupivacaine as a non-opioid analgesic for postoperative pain management.

INTRODUCTION: The use of non-narcotic modalities for postoperative analgesia may decrease exposure to opioids, thereby limiting their deleterious effects. The objective of this study was to determine the effectiveness of a liposomal bupivacaine transverse abdominis plane (TAP) block prior to laparoscopic sleeve gastrectomy (LSG) and laparoscopic gastric bypass (LRYGB). The primary outcome was total postoperative morphine equivalents. METHODS: A single-surgeon, IRB-approved retrospective chart review was performed on consecutive patients who underwent LRYGB or LSG from 2010 to 2016. Patients were grouped according to those who received TAP blocks immediately preoperatively with rescue opioids (TAP group) and those who received PCA only (PCA group). Total parenteral morphine equivalents (PME) were calculated. Numerical pain scores were collected immediately following surgery, 12 h postoperatively, and on the day of discharge. Median length of stay (LOS) and 30-day readmissions were also calculated. RESULTS: There were 440 patients who met inclusion criteria. The TAP group had significantly less opioid use (total PME) than the PCA, irrespective of surgical approach (70.4 ± 2.7 PCA LRYGB and 26.5 ± 1.5 TAP block LRYGB, p value ≤ 0.0001; 60.0 ± 3.5 PCA LSG vs. and 24.1 ± 2.0 TAP block LSG, p value < 0.0001). Median LOS was 2.0 days for both PCA groups, whereas LOS decreased to 1.0 day for both groups of patients receiving TAP blocks (p < 0.0001). Pain scores immediately following and 12 h after surgery were significantly elevated in the TAP LRYGB versus PCA LRYGB (p < 0.05) and immediately following surgery for PCA versus TAP block for LSG (p = 0.0109). CONCLUSIONS: TAP blocks with liposomal bupivacaine lead to significantly less use of parenteral morphine equivalents and decreased LOS compared to PCA alone. Pain scores were higher in the TAP LRYGB group compared to the LRYGB PCA group, with no differences in pain scores noted in the LSG groups.