Adrenomyeloneuropathy with Later Development of Cerebral Form Caused by a Hemizygous Splice-site Variant in ABCD1

Adrenomyeloneuropathy (AMN)/adrenoleukodystrophy (ALD) is an X-linked genetic disorder caused by pathogenic variants in ABCD1. We treated a 54-year-old man with slowly progressive spastic paraparesis with later development of the cerebral form. A pathogenic splice-site variant of ABCD1 (c.1489-1G>A, p.Val497Alafs*51) and elevated levels of very long-chain fatty acids were found, leading to the diagnosis of AMN. Detailed ABCD1 mRNA expression analyses revealed decreased levels of ABCD1 mRNA accompanied by deletion of the first 31 bp in exon 6. The altered mRNA transcriptional patterns associated with splice site variants are diverse and may provide important insights into ALD pathogenesis.

SPTLC2 variants are associated with early-onset ALS and FTD due to aberrant sphingolipid synthesis

OBJECTIVE

Amyotrophic lateral sclerosis (ALS) is a devastating, incurable neurodegenerative disease. A subset of ALS patients manifests with early-onset and complex clinical phenotypes. We aimed to elucidate the genetic basis of these cases to enhance our understanding of disease etiology and facilitate the development of targeted therapies.

METHODS

Our research commenced with an in-depth genetic and biochemical investigation of two specific families, each with a member diagnosed with early-onset ALS (onset age of <40 years). This involved whole-exome sequencing, trio analysis, protein structure analysis, and sphingolipid measurements. Subsequently, we expanded our analysis to 62 probands with early-onset ALS and further included 440 patients with adult-onset ALS and 1163 healthy controls to assess the prevalence of identified genetic variants.

RESULTS

We identified heterozygous variants in the serine palmitoyltransferase long chain base subunit 2 (SPTLC2) gene in patients with early-onset ALS. These variants, located in a region closely adjacent to ORMDL3, bear similarities to SPTLC1 variants previously implicated in early-onset ALS. Patients with ALS carrying these SPTLC2 variants displayed elevated plasma ceramide levels, indicative of increased serine palmitoyltransferase (SPT) activity leading to sphingolipid overproduction.

INTERPRETATION

Our study revealed novel SPTLC2 variants in patients with early-onset ALS exhibiting frontotemporal dementia. The combination of genetic evidence and the observed elevation in plasma ceramide levels establishes a crucial link between dysregulated sphingolipid metabolism and ALS pathogenesis. These findings expand our understanding of ALS's genetic diversity and highlight the distinct roles of gene defects within SPT subunits in its development.

A Case of a Patient with Calpainopathy Carrying Compound Heterozygous Mutations of a de novo Pathogenic Variant of c.1333G>A and a Novel Variant of c.1331C>T in CAPN3

Calpainopathy is primarily an autosomal recessive inherited myopathy; however, dominantly inherited cases with a pathogenic variant of c.1333G>A have been reported. A 13-year-old Japanese girl presented with toe walking and elevated serum creatine kinase levels. Genetic panel testing revealed compound heterozygosity for c.1333G>A and a novel variant of c.1331C>T in CAPN3, leading to a diagnosis of calpainopathy. A genetic analysis of her parents revealed the possibility that c.1333G>A was de novo. In this patient, the onset age was earlier than that of the reported autosomal dominant cases, suggesting the influence of the novel variant in the contralateral allele.

Rare Co-occurrence of Spinal Cord Hemorrhage from Radiation-induced Cavernous Hemangioma and Classical Hodgkin Lymphoma Post-transplant Lymphoproliferative Disorder

Post-transplant lymphoproliferative disorders (PTLDs) are lymphoproliferative diseases that occur after solid organ transplantation or hematopoietic stem cell transplantation (HSCT). The development of PTLD is often associated with reactivation of Epstein-Barr virus (EBV). A 26-year-old woman with a history of HSCT and total-body irradiation developed spinal cord hemorrhage from a radiation-induced cavernous hemangioma (RICH) shortly after the development of classical Hodgkin lymphoma PTLD with EBV reactivation. Although little is known about the factors leading to hemorrhagic events from spinal cord RICH, we suspect that EBV reactivation may have been a factor contributing to the hemorrhage in the present case.

Clinical and Genetic Features of Multiplex Families with Multiple System Atrophy and Parkinson's Disease

While multiple system atrophy (MSA) has been considered a sporadic disease, there were previously reported multiplex families with MSA. Furthermore, several families with multiple patients with MSA and Parkinson's disease (PD) have been reported. As genetic risk factors for MSA, functionally impaired variants in COQ2 and Gaucher-disease-causing GBA variants have been reported. While it has been established that GBA variants are associated with PD, COQ2 may also be associated with PD. In 672 patients with MSA, we identified 12 multiplex families of patients with MSA and PD in first-degree relatives. We conducted a detailed analysis of the clinical presentations of these patients and genetic analyses of GBA and COQ2. In the multiplex families, a patient with MSA with predominant parkinsonism (MSA-P) was observed in nine families, while a patient with MSA cerebellar subtype (MSA-C) was observed in three families. Six families had siblings with MSA and PD, five families had a parent-offspring pair with MSA and PD, and in one family, a sibling and a parent of an MSA patient had PD. In genetic analyses of these patients, GBA variants were identified in one of the 12 MSA patients and two of the seven PD patients. Functionally impaired variants of COQ2 were identified in two of the 12 MSA patients and not identified in the seven PD patients. This study further emphasizes the occurrence of MSA and PD in first-degree relatives, raising the possibility that a common genetic basis underlies MSA and PD. Even though variants of COQ2 and GBA were identified in some patients in multiplex families with MSA and PD, it is necessary to further explore as yet unidentified genetic risk factors shared by MSA and PD.

Safety of intranasal insulin administration in patients undergoing cardiovascular surgery: An open-label, nonrandomized, dose-escalation study

Objective

This study aimed to determine the maximum safe dose of intranasal insulin administration during cardiac surgery.

Methods

This open-label, Phase 1, single-center, dose-escalation clinical trial recruited patients scheduled to undergo elective cardiac surgery or major vascular surgery requiring cardiopulmonary bypass between February and September 2021. They were grouped into 5 dose-escalation cohorts and administered 0, 40, 80, 160, and 240 IU insulin (n = 6 in each group) via a metered nasal dispenser after the induction of general anesthesia. Blood samples were collected at 10-minute intervals for the first 60 minutes and at 30-minute intervals thereafter. Hypoglycemia was defined as a blood glucose level <70 mg/dL. Patient recruitment was terminated after hypoglycemia was observed in 2 patients in any of the groups.

Results

In total, 27 of 29 enrolled patients were administered intranasal insulin or saline. Hypoglycemia was not observed after the administration of intranasal insulin in the 0, 40, 80, or 160 IU groups; however, it was observed in 2 of 3 patients in the 240 IU group. The serum insulin concentration was elevated in the 160-IU group, but the C-peptide concentration was not elevated in any of the groups.

Conclusions

The administration of up to 160 IU intranasal insulin did not induce clinically significant hypoglycemia. However, 160 IU intranasal insulin should be administered cautiously because insulin can enter the systemic circulation in a dose-dependent manner.

Droperidol lowers the shivering threshold in rabbits

PURPOSE

Perioperative shivering is common and can occur as a result of hypothermia or changes in the threshold of thermoregulation. Droperidol usage for anesthesia is currently limited to its sedative and antiemetic effects. We investigated the effects of high and low doses of droperidol on the shivering threshold in rabbits.

METHODS

Forty-two male Japanese white rabbits were anesthetized with isoflurane and randomly assigned to the control, high-dose, or low-dose group. Rabbits in the high-dose group received a 5 mg/kg droperidol bolus followed by continuous infusion at 5 mg/kg/h, those in the low-dose group received a 0.5 mg/kg droperidol bolus, and those in the control group received the same volume of saline as the high-dose group. Body temperature was reduced at a rate of 2-3 °C/h, and the shivering threshold was defined as the subject's core temperature (°C) at the onset of shivering.

RESULTS

The shivering thresholds in the control, high-dose, and low-dose groups were 38.1 °C ± 1.1 °C, 36.7 °C ± 1.2 °C, and 36.9 °C ± 1.0 °C, respectively. The shivering thresholds were significantly lower in the high-dose and low-dose groups than in the control group (P < 0.01). The thresholds were comparable between the high-dose and low-dose groups.

CONCLUSIONS

Droperidol in high and low doses effectively reduced the shivering threshold in rabbits. Droperidol has been used in low doses as an antiemetic. Low doses of droperidol can reduce the incidence of shivering perioperatively and during the induction of therapeutic hypothermia.

Case Report: Intraventricular Cerliponase Alfa Treatment in a Patient with Advanced Neuronal Ceroid Lipofuscinosis Type 2

Neuronal ceroid lipofuscinosis type 2 (CLN2) is an autosomal recessive lysosomal disease caused by decreased activity of the enzyme tripeptidyl peptidase 1 (TPP1) due to pathogenic variants in the TPP1 gene. Cerliponase alfa, a recombinant proenzyme form of TPP1, has shown efficacy in preventing motor and language function decline in early-stage CLN2. However, the safety and effects of this therapy in advanced-stage CLN2 are unclear. We herein report a case of intraventricular cerliponase alfa treatment for over a year in a patient with advanced-stage CLN2. The results suggest the safety and potential efficacy of treatment at an advanced stage of CLN2.

Noncanonical splice-site variant in peripheral myelin protein 22 gene (PMP22) in a patient with hereditary neuropathy with liability to pressure palsies

AIM

Hereditary neuropathy with liability to pressure palsies (HNPP) is a peripheral neuropathy with autosomal dominant inheritance. Diagnosis can be made from the characteristic abnormalities determined by nerve conduction studies (NCS), including subclinical deficits at physiological compression sites. Heterozygous deletion of the chromosome 17p11.2-p12 region including the peripheral myelin protein 22 gene (PMP22) is the cause in the majority of cases. However, the loss of function of PMP22 due to frameshift-causing insertion/deletion, missense, nonsense, or splice-site disrupting variants cause HNPP in some patients. We report a case of a patient diagnosed with HNPP on the basis of clinical features and the results of NCS. No deletions of PMP22 were detected by fluorescence in situ hybridization.

METHODS

We performed direct nucleotide sequence analysis and identified a heterozygous variant, c.78 + 3G > T, in PMP22. Since this variant is located outside the canonical splice site at the exon 2-intron 2 junction, we investigated whether the variant causes aberrant splicing and leads to the skipping of exon 2 of PMP22 by in vitro minigene splicing assay.

RESULTS

We demonstrated that the c.78 + 3G > T variant causes the skipping of exon 2 and leads to loss of function of the mutant allele.

CONCLUSION

Searching for sequence variants located outside the canonical splice sites should also be considered even when deletion of PMP22 is not found in a patient with a clinical diagnosis suggesting HNPP.

Role of the protein kinase A signaling pathway and identification of mediators in the cardioprotective effects of enteral lactoferrin for ischemia-reperfusion injury in an isolated rat heart model

OBJECTIVE

Lactoferrin is an iron-binding glycoprotein. Enteral lactoferrin attenuates myocardial ischemia-reperfusion (IR) injury, but the underlying mechanism remains unknown. The aim of this study was to investigate protein kinase A (PKA) signaling pathway activation and levels of serum glucagonlike peptide-1 (GLP-1), secreted by intestinal endocrine L cells, and adiponectin, secreted by adipose tissue, after enteral lactoferrin administration.

METHODS

Hearts (N = 32) were excised from Wistar rats and perfused using a Langendorff system. To assess the role of the PKA pathway in the cardioprotective effects of lactoferrin, an inhibitor of PKA (H89) was applied before no-flow ischemia. Rats were randomly divided into four groups: control, lactoferrin (LF), control+H89, and LF+H89. The control and control+H89 groups were administered normal saline by gavage, and the LF and L +H89 groups were administered bovine lactoferrin (1000 mg/kg) by gavage 15 min before intraperitoneal pentobarbital injection. Muscle sampling was performed at the end of reperfusion. When rats were sacrificed, blood was sampled to measure hormone levels. The primary outcome was maximum left ventricular pressure derivative (LV dP/dt max) 15 min after reperfusion.

RESULTS

LV dP/dt max at 10 and 15 min after reperfusion was significantly higher in the LF group than in the control group (P < 0.05), and the effect was diminished by H89. The PKA pathway was significantly activated in the LF group. Enteral lactoferrin increased serum GLP-1 but not serum adiponectin levels.

CONCLUSIONS

Enteral lactoferrin induces cardioprotective effects against myocardial IR injury via the PKA signaling pathway and increases serum GLP-1 levels.

LONRF2 is a protein quality control ubiquitin ligase whose deficiency causes late-onset neurological deficits

Protein misfolding is a major factor of neurodegenerative diseases. Post-mitotic neurons are highly susceptible to protein aggregates that are not diluted by mitosis. Therefore, post-mitotic cells may have a specific protein quality control system. Here, we show that LONRF2 is a bona fide protein quality control ubiquitin ligase induced in post-mitotic senescent cells. Under unperturbed conditions, LONRF2 is predominantly expressed in neurons. LONRF2 binds and ubiquitylates abnormally structured TDP-43 and hnRNP M1 and artificially misfolded proteins. Lonrf2-/- mice exhibit age-dependent TDP-43-mediated motor neuron (MN) degeneration and cerebellar ataxia. Mouse induced pluripotent stem cell-derived MNs lacking LONRF2 showed reduced survival, shortening of neurites and accumulation of pTDP-43 and G3BP1 after long-term culture. The shortening of neurites in MNs from patients with amyotrophic lateral sclerosis is rescued by ectopic expression of LONRF2. Our findings reveal that LONRF2 is a protein quality control ligase whose loss may contribute to MN degeneration and motor deficits.

Neurofilament light chain levels in cerebrospinal fluid as a sensitive biomarker for cerebral adrenoleukodystrophy

OBJECTIVE

Adrenoleukodystrophy (ALD) has a poor prognosis when it progresses to the cerebral form (CALD). The aim of this study is to investigate whether cerebrospinal fluid (CSF) neurofilament light chain (cNfL) is a sensitive biomarker for detecting CALD and assessing response to hematopoietic stem cell transplantation (HSCT).

METHODS

We conducted a cross-sectional study of 41 male ALD patients. The cNfL levels in patients with the cerebral form of ALD (CALD) or the cerebello-brainstem form of ALD were compared with those in patients with adrenomyeloneuropathy (AMN). The correlation between cNfL levels and MRI-based Loes severity scores was investigated. A longitudinal analysis was performed on patients who underwent multiple CSF examinations.

RESULTS

The cNfL levels in 22 patients with CALD were significantly higher than those in 14 patients with AMN (median, 5545 vs. 1490 pg/mL; p < 0.001). The cutoff cNfL level of 1930 pg/mL showed good sensitivity (95.5%) and specificity (85.7%) for distinguishing CALD from AMN. The cNfL levels were positively correlated with Loes scores (p < 0.001). The cNfL levels in three AMN patients who later converted to CALD increased above the cutoff level during the conversion period, while the cNfL levels in four patients who remained in AMN were consistently below the cutoff. In 10 ALD patients who underwent HSCT, their cNfL levels decreased 3-24 months after HSCT. Two patients whose cNfL increased after HSCT showed deterioration in cognitive functions.

INTERPRETATION

The cNfL level is useful for evaluating the disease activities of ALD and the response to HSCT.

Epidural Hematoma related to lower limb pain and massive liver bleeding in Gorham-Stout disease: A case report

RATIONALE

Gorham-Stout disease (GSD) is a rare disease that causes massive osteolysis and proliferation of abnormal lymphangiomatous tissues. Patients with GSD often experience pain associated with bone fractures and chylothorax. However, bleeding caused by abnormal lymphangiomatous tissue or hematological dysfunction rarely occurs.

PATIENT CONCERNS

A 22-year-old female patient with GSD presented with severe left hip and lower limb pain. The GSD had disappeared her right pelvic bone and femur, but no abnormalities were found in the bones at the site of the pain.

DIAGNOSES

The patient presented with a chylothorax and cerebrospinal fluid leakage. She was treated with sirolimus and an epidural blood patch, and her symptoms resolved. Computed tomography and magnetic resonance imaging revealed an epidural hematoma extending from L3 to the caudal region, and blood results revealed a consumption coagulopathy.

INTERVENTIONS

We presumed that the hematoma caused pain and prescribed pregabalin and morphine. The pain gradually subsided.

OUTCOMES

An unexpected liver subcapsular hemorrhage occurred 4 months later, and the patient went into hemorrhagic shock. Transcatheter arterial embolization was promptly performed, and the patient recovered.

LESSONS

GSD infrequently causes bleeding related to abnormal lymphangiomatous tissues and coagulopathy, yet it can lead to serious events if it occurs.

Genome-wide association study identifies a new susceptibility locus in PLA2G4C for Multiple System Atrophy

To elucidate the molecular basis of multiple system atrophy (MSA), a neurodegenerative disease, we conducted a genome-wide association study (GWAS) in a Japanese MSA case/control series followed by replication studies in Japanese, Korean, Chinese, European and North American samples. In the GWAS stage rs2303744 on chromosome 19 showed a suggestive association ( P = 6.5 × 10 ^-7 ) that was replicated in additional Japanese samples ( P = 2.9 × 10 ^-6 . OR = 1.58; 95% confidence interval, 1.30 to 1.91), and then confirmed as highly significant in a meta-analysis of East Asian population data ( P = 5.0 × 10 ^-15 . Odds ratio= 1.49; 95% CI 1.35 to 1.72). The association of rs2303744 with MSA remained significant in combined European/North American samples ( P =0.023. Odds ratio=1.14; 95% CI 1.02 to 1.28) despite allele frequencies being quite different between these populations. rs2303744 leads to an amino acid substitution in PLA2G4C that encodes the cPLA2γ lysophospholipase/transacylase. The cPLA2γ-Ile143 isoform encoded by the MSA risk allele has significantly decreased transacylase activity compared with the alternate cPLA2γ-Val143 isoform that may perturb membrane phospholipids and α-synuclein biology.

Role of macrophage autophagy in postoperative pain and inflammation in mice

BACKGROUND

Postoperative pain and inflammation are significant complications following surgery. Strategies that aim to prevent excessive inflammation without hampering natural wound-healing are required for the management of postoperative pain and inflammation. However, the knowledge of the mechanisms and target pathways involved in these processes is lacking. Recent studies have revealed that autophagy in macrophages sequesters pro-inflammatory mediators, and it is therefore being recognized as a crucial process involved in regulating inflammation. In this study, we tested the hypothesis that autophagy in macrophages plays protective roles against postoperative pain and inflammation and investigated the underlying mechanisms.

METHODS

Postoperative pain was induced by plantar incision under isoflurane anesthesia in mice lacking macrophage autophagy (Atg5flox/flox LysMCre +) and their control littermates (Atg5flox/flox). Mechanical and thermal pain sensitivity, changes in weight distribution, spontaneous locomotor activity, tissue inflammation, and body weight were assessed at baseline and 1, 3, and 7 days after surgery. Monocyte/macrophage infiltration at the surgical site and inflammatory mediator expression levels were evaluated.

RESULTS

Atg5flox/flox LysMCre + mice compared with the control mice exhibited lower mechanical and thermal pain thresholds and surgical/non-surgical hindlimb weight-bearing ratios. The augmented neurobehavioral symptoms observed in the Atg5flox/flox LysMCre + mice were associated with more severe paw inflammation, higher pro-inflammatory mediator mRNA expression, and more monocytes/macrophages at the surgical site.

CONCLUSION

The lack of macrophage autophagy augmented postoperative pain and inflammation, which were accompanied by enhanced pro-inflammatory cytokine secretion and surgical-site monocyte/macrophage infiltration. Macrophage autophagy plays a protective role in postoperative pain and inflammation and can be a novel therapeutic target.

High-dose ubiquinol supplementation in multiple-system atrophy: a multicentre, randomised, double-blinded, placebo-controlled phase 2 trial

Background

Functionally impaired variants of COQ2, encoding an enzyme in biosynthesis of coenzyme Q10 (CoQ10), were found in familial multiple system atrophy (MSA) and V393A in COQ2 is associated with sporadic MSA. Furthermore, reduced levels of CoQ10 have been demonstrated in MSA patients.

Methods

This study was a multicentre, randomised, double-blinded, placebo-controlled phase 2 trial. Patients with MSA were randomly assigned (1:1) to either ubiquinol (1500 mg/day) or placebo. The primary efficacy outcome was the change in the unified multiple system atrophy rating scale (UMSARS) part 2 at 48 weeks. Efficacy was assessed in all patients who completed at least one efficacy assessment (full analysis set). Safety analyses included patients who completed at least one dose of investigational drug. This trial is registered with UMIN-CTR (UMIN000031771), where the drug name of MSA-01 was used to designate ubiquinol.

Findings

Between June 26, 2018, and May 27, 2019, 139 patients were enrolled and randomly assigned to the ubiquinol group (n = 69) or the placebo group (n = 70). A total of 131 patients were included in the full analysis set (63 in the ubiquinol group; 68 in the placebo group). This study met the primary efficacy outcome (least square mean difference in UMSARS part 2 score (-1.7 [95% CI, -3.2 to -0.2]; P = 0.023)). The ubiquinol group also showed better secondary efficacy outcomes (Barthel index, Scale for the Assessment and Rating of Ataxia, and time required to walk 10 m). Rates of adverse events potentially related to the investigational drug were comparable between ubiquinol (n = 15 [23.8%]) and placebo (n = 21 [30.9%]).

Interpretation

High-dose ubiquinol was well-tolerated and led to a significantly smaller decline of UMSARS part 2 score compared with placebo.

Funding

Japan Agency for Medical Research and Development.

Risk factors for postoperative complications in patients with Parkinson disease: A single center retrospective cohort study

Surgical treatment for patients with Parkinson disease (PD) under general anesthesia has become frequent. PD is a significant predictor of postoperative complications. However, the factors that predict complications in patients with PD remain unknown. We retrospectively recruited patients with PD who underwent surgery between April 2015 and March 2019. The prevalence of postoperative complications was analyzed. We compared the patient characteristics, medical data, and surgical data between patients with and without postoperative complications. We also estimated the odds ratios (OR) for postoperative complications in patients with PD who underwent surgery. Sixty-five patients were enrolled. Eighteen patients presented with 22 complications, including urinary tract infections (UTI) (n = 3; 5%), pneumonia (n = 1; 2%), surgical site infections (SSI) (n = 3; 5%), postoperative delirium (POD) (n = 7; 10%), and others (n = 8; 12%). Four patients presented with 2 complications each. The operation time, the red blood cell transfusion and the rate of rotigotine usage were higher in patients with complications than those without (314 ± 197 min vs 173 ± 145 min, P = .006; 0 [0-560] mL vs 0 [0-0] mL, P = .02; 39% vs 6%, P = .003, respectively) (mean ± standard deviation or median [interquartile range]). Preoperative rotigotine usage (OR: 9.33; 95% confidential interval [CI]: 2.07-42.07; P = .004) was an independent risk factors for postoperative complications. The findings indicate that clinicians should closely monitor postoperative complications when patients with PD who have received transdermal dopamine agonists undergone longer time surgery.

Favorable outcome of hematopoietic stem cell transplantation in late-onset Krabbe disease

BACKGROUND

Late-onset Krabbe disease is a disorder with autosomal recessive inheritance caused by a deficiency in galactocerebrosidase (GALC) activity. Its late-onset form usually shows slow disease progression with atypical symptoms including spastic paresis. The efficacy of hematopoietic stem cell transplantation (HSCT) in late-onset Krabbe disease has not been fully established.

CASE REPORT

We describe the case of a patient with late-onset Krabbe disease showing progressive spastic paraparesis. At the age of 18, one and a half years after the development of symptoms, the patient underwent HSCT. After HSCT, the patient's GALC activity returned to a normal level and the lesions in the brain and spinal cord became faint on images. Over two and a half years after the HSCT, the patient's gait remained spastic, however, an improvement in gait speed and modified Rankin Scale score was observed. No severe adverse events occurred during this period.

CONCLUSION

Our experience reported herein provides additional evidence for a favorable course in HSCT conducted in the early course of late-onset Krabbe disease.

Somatic GJA4 gain-of-function mutation in orbital cavernous venous malformations

Orbital cavernous venous malformation (OCVM) is a sporadic vascular anomaly of uncertain etiology characterized by abnormally dilated vascular channels. Here, we identify a somatic missense mutation, c.121G > T (p.Gly41Cys) in GJA4, which encodes a transmembrane protein that is a component of gap junctions and hemichannels in the vascular system, in OCVM tissues from 25/26 (96.2%) individuals with OCVM. GJA4 expression was detected in OCVM tissue including endothelial cells and the stroma, through immunohistochemistry. Within OCVM tissue, the mutation allele frequency was higher in endothelial cell-enriched fractions obtained using magnetic-activated cell sorting. Whole-cell voltage clamp analysis in Xenopus oocytes revealed that GJA4 c.121G > T (p.Gly41Cys) is a gain-of-function mutation that leads to the formation of a hyperactive hemichannel. Overexpression of the mutant protein in human umbilical vein endothelial cells led to a loss of cellular integrity, which was rescued by carbenoxolone, a non-specific gap junction/hemichannel inhibitor. Our data suggest that GJA4 c.121G > T (p.Gly41Cys) is a potential driver gene mutation for OCVM. We propose that hyperactive hemichannel plays a role in the development of this vascular phenotype.

Effects of adrenaline and vasopressin on cerebral microcirculation at baseline and during global brain ischemia and reperfusion in rabbits

BACKGROUND

During cardiopulmonary resuscitation, the brain becomes ischemic. Adrenaline and vasopressin have been recommended for use during cardiopulmonary resuscitation. We aimed to investigate the direct effects of adrenaline and vasopressin on the cerebral microvasculature at baseline and during ischemia and reperfusion in rabbits.

METHODS

The closed cranial window method was used to visualize the cerebral microcirculation and changes in the pial arteriole diameter in rabbits. Adrenaline and vasopressin were administered topically on the brain tissue. First, the effects of adrenaline and vasopressin on pial arterioles were evaluated in 7 rabbits that were given 4 different concentrations of adrenaline, and another 7 rabbits that received 4 different concentrations of vasopressin. Second, the effects of adrenaline and vasopressin were determined during the global brain ischemia and reperfusion, which was induced by clamping the brachiocephalic, left common carotid, and left subclavian arteries for 15 min. An additional 21 rabbits were randomly assigned to receive artificial cerebrospinal fluid (aCSF) (n = 7), adrenaline 10^-5 mol/L (n = 7), or vasopressin 10^-7 mol/L (n = 7). Each drug was continuously infused from 5 min after the initiation of ischemia until 120 min after reperfusion. The pial arteriole diameters were recorded before and during ischemia, and after reperfusion.

RESULTS

At baseline, adrenaline and vasopressin did not affect the cerebral pial arterioles. During ischemia, vasopressin, but not aCSF and adrenaline constricted the pial vessels. Late in the reperfusion phase, pial diameter became reduced in the vasopressin and aCSF groups whereas pial diameter was higher in the animals treated with adrenaline.

CONCLUSIONS

Adrenaline and vasopressin did not affect pial arterioles at baseline. During reperfusion, adrenaline may counteract the cerebral vasoconstriction.

Influence of pneumoperitoneum and head-down maneuver on the cerebral microvasculature in rabbits

BACKGROUND

With recent advances in robot-assisted techniques, an increasing number of surgeries are being performed with pneumoperitoneum and head-down maneuver (HDM) that may affect the cerebral microcirculation. For the first time, this study investigated the direct influence of pneumoperitoneum and HDM on the cerebral microvasculature in rabbits.

METHODS

Adult male rabbits were randomly allocated to the following groups (n = 7 each): control, pneumoperitoneum alone (P), and pneumoperitoneum with HDM (P + HDM) for 120 min. A closed cranial window was installed above the parietal bone to visualize the pial microvasculature. Pial arteriolar diameter and hemodynamic and blood gas parameters were measured during the 140-min observation period. Brain edema was assessed by evaluation of the brain water content at the end of the experiment.

RESULTS

Rabbits in the P and P + HDM groups exhibited a similar degree of immediate pial arteriolar dilation following the initiation of both P and P + HDM (P: 1.11 ± 0.03, p = 0.0044 and P + HDM: 1.07 ± 0.02, p = 0.0004, relative changes from the baseline value by defining the baseline as one). In the P + HDM group, pial arteriole diameter returned to the baseline level following the discontinuation of pneumoperitoneum and HDM (1.05 ± 0.03, p = 0.0906, vs. baseline). In contrast, the pial arterioles remained dilated as compared to the baseline level in the P group after discontinuation of pneumoperitoneum. There were no changes in pial arteriole diameter in the animals in the control group. Heart rate, blood gas parameters, and brain water content were not significantly different between the groups.

CONCLUSION

The pial arterioles dilated immediately after pneumoperitoneum with or without HDM. The pial arterioles remained dilated 20 min after discontinuation of pneumoperitoneum alone but constricted upon discontinuation of pneumoperitoneum plus HDM. Pneumoperitoneum and HDM for 2 h did not cause brain edema.

Cardioprotective effects of enteral vs. parenteral lactoferrin administration on myocardial ischemia-reperfusion injury in a rat model of stunned myocardium

BACKGROUND

Lactoferrin, an iron-binding glycoprotein, is known to have protective effects against intestinal and cerebral ischemia-reperfusion (IR) injuries; however, its cardioprotective effects against the stunned myocardium are unknown. This study aimed to test the hypothesis that lactoferrin has cardioprotective effects against stunned myocardium.

METHODS

Using isolated rat hearts (Langendorff system), we determined the effects of lactoferrin administered enterally and by direct cardiac perfusion. Rat hearts were perfused using the Langendorff system, and two experiments were performed. In experiment 1, the hearts were divided into the enteral lactoferrin (E-LF) 7.5 m, 15 m, 30 m, and 60 m groups, where lactoferrin (1000 mg/kg) was administered enterally 7.5, 15, 30, and 60 min, respectively, before perfusion; and a control group, where saline was administered 30 min before perfusion. In experiment 2, hearts were allocated to the perfusate lactoferrin (P-LF) 15 and 100 groups, where 15 mg/L and 100 mg/L lactoferrin were respectively added to the perfusate, and a control group. Each group was perfused for 20 min prior to 15 min of no-flow ischemia with pacing, followed by 20 min of reperfusion. The primary outcome was the maximum left ventricular derivative of pressure development (LV dP/dt max) 15 min after reperfusion. Myocardial phospho-protein kinase B (p-Akt) was assayed using western blotting.

RESULTS

The LV dP/dt max 15 min after reperfusion in the E-LF 15 and 30 m groups was significantly higher than that in the control group. However, the effects disappeared in the E-LF 60 m group. In the second experiment, there were no significant differences in LV dP/dt max. Myocardial p-Akt was not significantly activated in any lactoferrin group.

CONCLUSION

Cardioprotection was observed 15-30 min after enteral lactoferrin but not by direct cardiac perfusion with lactoferrin. Myocardial p-Akt was not associated with the cardioprotective effect. The cardioprotective effect may be induced by enteral lactoferrin-induced substances.

Novel ultrashort-acting benzodiazepine remimazolam lowers shivering threshold in rabbits

Shivering after surgery or during therapeutic hypothermia can lead to serious complications, such as myocardial infarction and respiratory failure. Although several anesthetics and opioids are shown to have anti-shivering effects, their sedative and respiratory side effects dampen the usefulness of these drugs for the prevention of shivering. In the present study, we explored the potential of a novel ultrashort-acting benzodiazepine, remimazolam, in the prevention of shivering using a rabbit model of hypothermia. Adult male Japanese white rabbits were anesthetized with isoflurane. The rabbits received saline (control), remimazolam (either 0.1 or 1 mg/kg/h), or remimazolam + flumazenil, a selective γ-aminobutyric acid (GABA) type A receptor antagonist (n = 6 each). Thirty minutes after discontinuation of the drugs, cooling was initiated by perfusing 10°C water via a plastic tube positioned in the colon until the animal shivered. Core body temperature and hemodynamic and physiological parameters were recorded. Remimazolam at 1 mg/kg/h significantly lowered the core temperature change during shivering (−2.50 ± 0.20°C vs. control: −1.00 ± 0.12°C, p = 0.0009). The effect of 1 mg/kg/h remimazolam on the core temperature change was abolished by flumazenil administration (−0.94 ± 0.16°C vs. control: −1.00 ± 0.12°C, p = 0.996). Most of the hemodynamic and physiological parameters did not differ significantly among groups during cooling. Remimazolam at a clinically relevant dose successfully suppressed shivering in rabbits via the GABA pathway even after its anesthetic effects likely disappeared. Remimazolam may have the potential to prevent shivering in patients undergoing surgery or therapeutic hypothermia.

Anesthetic experience does not reduce accidental dural puncture in surgical patients: a retrospective case-controlled study

Background

Accidental dural puncture (ADP), which is a complication of epidural anesthesia, still exists and leads to worse outcomes in surgical patients. While residency training is important for epidural competency, it remains unknown whether anesthetic experience reduces ADP in surgical patients. Using an incident reporting system along with anesthetic records, this case-controlled study retrospectively investigated risk factors associated with ADP in surgical patients.

Methods

Patients who experienced ADP during epidural anesthesia who were registered in the incident reporting system of our institution between April 2012 and March 2019 were enrolled. Patients with ADP were control-matched with those who without ADP in a 1:3 ratio, to compare the potential risk factors and calculated odds ratios (ORs) for ADP. The primary hypothesis was that anesthesiologists’ experience reduces the incidence of ADP. The secondary hypothesis was that there are risk factors for ADP. Between-group differences in anesthesiologists’ experience were compared using the Mann–Whitney U test. Significance was set at P < 0.05.

Results

Thirty-five patients who experienced ADP were identified from the incident reporting system. These were matched with 69 patients who did not experience ADP. There was no difference in the years of experience of anesthesiologists between the groups that did and did not experience ADP (8 [3–20] vs. 9 [3–18] years, respectively; P = 0.65).

Conclusions

Having an experienced anesthesiologist did not guarantee the prevention of ADP. Daily individual training and briefings would be needed to reduce the incidence of ADP.

Short Sleep Duration on the Night Before Surgery Is Associated With Postoperative Cognitive Decline in Elderly Patients: A Prospective Cohort Study

As the world is rapidly aging, and the number of elderly patients who undergo surgery is rising, postoperative cognitive decline among those patients has become an increasing healthcare problem. Although understanding the risk factors and mechanisms underlying the pathogenesis of postoperative cognitive decline is critically important from a preventative viewpoint, such knowledge and evidence are lacking. A growing body of evidence suggest an association between cognitive function and sleep duration. The purpose of this study was to investigate the association between postoperative cognitive function and sleep duration on the night before surgery using a wearable sleep tracker. In this 6-month prospective cohort study, we analyzed data from 194 patients aged ≥ 65 years who underwent elective non-cardiac and non-cranial surgery under general anesthesia. According to the sleep duration on the night before surgery, patients were categorized into following four groups: <5, 5–7, 7–9, and >9 h. Perioperative cognitive function and domains were assessed using a neuropsychological test battery, and the incidence and prevalence of cognitive decline over 6 months after surgery were analyzed using the multiple logistic regression analysis. During the 6-month follow-up period, 41 patients (21%) developed cognitive decline. The incidence of cognitive decline was significantly elevated for the patients with sleep duration < 5 h (vs. 7–9 h; surgical duration-adjusted odds ratio, 3.50; 95% confidence interval, 1.20–10.2; P < 0.05). The association between sleep duration and prevalence of cognitive decline was limited to the early postoperative period (at 1 week and 1 month). Among the cognitive domains assessed, attentional function was significantly impaired in patients with a sleep duration < 5 h [vs. 7–9 h at 1 week; 4/37 (10.8%) vs. 0/73 (0%); P < 0.05]. In conclusion, sleep duration < 5 h on the night before surgery was significantly associated with worse attentional function after surgery and higher incidence of cognitive decline. The present results indicate that sleep deprivation on the night before surgery may have a temporary but significantly negative influence on the patient's postoperative cognitive function and is a potential target for preventing cognitive decline.

Propofol ameliorates ischemic brain injury by blocking TLR4 pathway in mice

Ischemic brain injury is one of the most serious perioperative complications. However, effective preventative methods have not yet been established. This study aimed to investigate whether propofol has neuroprotective effects against ischemic brain injury, with a specific focus on Toll-like receptor 4 (TLR4). Focal brain ischemia was induced via a combination of left common carotid artery occlusion and distal left middle cerebral artery coagulation in mice. Either propofol (10 mg/kg) or vehicle was intravenously injected 10 min prior to the induction of brain ischemia in wild-type and TLR4 knockout mice. Infarct volume, pro-inflammatory cytokine expression, inflammatory cell infiltration, and neurobehavioral function were assessed. Propofol administration significantly reduced infarct volume in wild-type mice (26.9 ± 2.7 vs 15.7 ± 2.0 mm³ at day 7), but not in TLR4 knockout mice. Compared with the control mice, the propofol-treated wild-type mice exhibited lower levels of IL-6 (0.57 ± 0.23 vs 1.00 ± 0.39 at 24 h), and smaller numbers of TLR4-expressing microglia in the penumbra (11.7 ± 3.1 vs 25.1 ± 4.7 cells/0.1 mm²). In conclusion, propofol administration prior to ischemic brain insult attenuated brain injury by blocking the TLR4-dependent pathway and suppressing pro-inflammatory cytokine production.

COQ2 V393A confers high risk susceptibility for multiple system atrophy in East Asian population

Multiple system atrophy (MSA) is a rare, late-onset, and devastating neurodegenerative disease characterized by autonomic failure, alongside with various combination of parkinsonism, cerebellar ataxia, and pyramidal dysfunction. Since we first identified biallelic mutations in the COQ2 gene in two multiplex MSA families and further reported that heterozygous COQ2 V393A variant confers a susceptibility to sporadic MSA, the results of nearly a decade of investigating this association globally were quite remarkable. COQ2 V393A was virtually absent in the American and European populations but was shown to have varying associations with sporadic MSA in the East Asian populations. In our attempt to clarify the latter and provide a coherent regional conclusion, we conducted two independent case-control series which showed clear association of the V393A variant with sporadic MSA in the Japanese population. We then pooled the results with other studies from the East Asian population and conducted a meta-analysis which broadened and established the association regionally (pooled OR 2.12, 95% CI: 1.35-3.31, PI: 0.63-7.15, p = 0.0047). The subgroup analysis identified a strong association of V393A with MSA-C (pooled OR 2.57, 95% CI: 1.98-3.35; p = 2.56 × 10^-12) but not with MSA-P (pooled OR 1.41, 95% CI: 0.88-2.26; p = 0.16). Our results highlighted the importance of investigating region-specific and pan-regional genetic variants that may potentially underlie the pathomechanisms of neurodegenerative diseases. COQ2 V393A variant remains a susceptibility variant rather than causative for MSA particularly, MSA-C subtype, in the East Asian population.

Intranasal administration of 40 and 80 units of insulin does not cause hypoglycemia during cardiac surgery: a randomized controlled trial

PURPOSE

Intranasal insulin administration may improve cognitive function in patients with dementia and may prevent cognitive problems after surgery. Although the metabolic effects of intranasal insulin in non-surgical patients have been studied, its influence on glucose concentration during surgery is unknown.

METHODS

We conducted a randomized, double-blind, placebo-contolled trial in patients scheduled for elective cardiac surgery. Patients with type 2 diabetes mellitus (T2DM) and non-T2DM patients were randomly allocated to one of three groups (normal saline, 40 international units [IU] of intranasal insulin, and 80 IU intranasal insulin). Insulin was given after the induction of general anesthesia. Glucose and plasma insulin concentrations were measured in ten-minute intervals during the first hour and every 30 min thereafter. The primary outcome was the change in glucose concentration 30 min after intranasal insulin administration.

RESULTS

A total of 115 patients were studied, 43 of whom had T2DM. In non-T2DM patients, 40 IU intranasal insulin did not affect glucose concentration, while 80 IU intranasal insulin led to a statistically significant but not clinically important decrease in blood glucose levels (mean difference, 0.4 mMol·L^-1; 95% confidence interval, 0.1 to 0.7). In T2DM patients, neither 40 IU nor 80 IU of insulin affected glucose concentration. No hypoglycemia (< 4.0 mMol·L^-1) was observed after intranasal insulin administration in any patients. In non-T2DM patients, changes in plasma insulin were similar in the three groups. In T2DM patients, there was an increase in plasma insulin concentrations ten minutes after administration of 80 IU of intranasal insulin compared with saline.

CONCLUSIONS

In patients with and without T2DM undergoing elective cardiac surgery, intranasal insulin administration at doses as high as 80 IU did not cause clinically important hypoglycemia.

TRIAL REGISTRATION

www.ClinicalTrials.gov (NCT02729064); registered 5 April 2016.

Ulinastatin attenuates protamine-induced cardiotoxicity in rats by inhibiting tumor necrosis factor alpha

Protamine causes cardiac depression, which may be mediated by tumor necrosis factor alpha (TNF-α). Ulinastatin, a human urinary protease inhibitor, inhibits TNF-α. Here, we aimed to investigate whether ulinastatin prevented protamine-induced myocardial depression by inhibiting TNF-α. Rat hearts were perfused using a Langendorff system, and three protocols were followed. Protocol 1: The hearts were divided into saline, ulinastatin-low, and ulinastatin-high groups. Protamine was administered to each group, and myocardial contractility was the primary outcome. Protocol 2: The hearts were allotted to saline or ulinastatin group. Protamine was administered to each group. TNF-α expression in the coronary effluent and myocardial tissue was measured. Protocol 3: The hearts were allotted to saline and ulinastatin groups. Recombinant rat-TNF-α was administered to each group. Protamine alone reduced the maximum left ventricular pressure derivative (LV dP/dt max) by 45 ± 4%. In contrast, the reduction in LV dP/dt max was 4 ± 3% in the ulinastatin-high group. Compared with that in the saline group, the increase in TNF-α in the coronary effluent was attenuated in the ulinastatin group. Recombinant TNF-α alone reduced LV dP/dt max (- 21 ± 14%). In contrast, when TNF-α was added in the presence of ulinastatin, the decrease in LV dP/dt max was prevented significantly (- 3 ± 8%). We showed, for the first time, that ulinastatin protected against protamine-induced myocardial damage, both by inhibiting TNF-α synthesis and by directly preventing the cardiodepressant action of TNF-α.

Delayed awakening with apnea as a sign of cerebellar hemorrhage after vestibular schwannoma surgery: A case report

Cerebellar hemorrhage after surgery is a rare but critical complication requiring prompt diagnosis and intervention. However, anesthetics can mask most brain compression signs. Prolonged coma with apnea after tumor resection under general anesthesia may indicate the need for prompt imaging to detect or exclude cerebellar lesions.

Cerebellar Ataxia as a Common Clinical Presentation Associated with DNMT1 p.Y511H and a Review of the Literature

The phenotypes of patients with disease-associated variants in DNMT1 have been classified into two syndromes: hereditary sensory and autonomic neuropathy type 1E (HSAN1E, MIM614116, https://www.omim.org/ ) and autosomal dominant cerebellar ataxia, deafness, and narcolepsy (ADCA-DN, MIM604121). The amino acid codon 511 is a hotspot, and p.Y511C is the most frequently observed disease-associated variant among those in HSAN1E patients, whereas there have been only a few reports on patients with p.Y511H. In this study, we report on the cases of a kindred carrying the DNMT1 variant NM_001130823.2:c.1531 T > C (p.Y511H) presenting with the ADCA-DN phenotype. The review of the literature further revealed that later ages at onset and the presence of cerebellar ataxia are the main characteristics of patients carrying the DNMT1 p.Y511H as compared with those carrying DNMT1 p.Y511C. Although HSAN1E and ADCA-DN are proposed to be called DNMT1-complex disorders owing to their overlapping symptoms, this finding suggests a distinct genotype-phenotype correlation regarding the DNMT1 p.Y511H and p.Y511C variants.

Juvenile amyotrophic lateral sclerosis with complex phenotypes associated with novel SYNE1 mutations

Mutations in SYNE1 have been originally described to cause a slowly progressive, pure cerebellar ataxia (spinocerebellar ataxia, autosomal-recessive 8; SCAR8). Notably, recent studies revealed that affected patients with SYNE1-associated ataxia can present with complex phenotypes rather than pure cerebellar ataxia, including motor neuron and brainstem dysfunctions. We herein report a Japanese patient diagnosed with juvenile amyotrophic lateral sclerosis (ALS) with a complex phenotype, who carried compound heterozygous pathogenic variants in SYNE1. Of the variants, one was a novel frameshift variant and the other was a nonsense variant previously reported as pathogenic for SCAR8. The patient showed an early age at onset with a relatively slow but progressive course of ALS, accompanied by cognitive decline. Our findings suggest that the clinical spectrum of patients carrying pathogenic SYNE1 variants is broader than expected, and SYNE1 variants should be considered in patients diagnosed with juvenile ALS, even without prominent cerebellar ataxia.

Splice-site mutations in KIF5A in the Japanese case series of amyotrophic lateral sclerosis

Our objective was to investigate the frequency of KIF5A variants in amyotrophic lateral sclerosis (ALS) and the clinical characteristics of familial ALS (FALS) associated with variants in KIF5A. Whole-exome sequence analysis was performed for a Japanese series of 43 families with FALS and 444 patients with sporadic ALS (SALS), in whom causative variants had not been identified. We compared the frequencies of rare variants (MAF < 0.01) in KIF5A, including missense and loss of function (LoF) variants, between ALS and control subjects (n = 1163). Clinical characteristics of patients with FALS carrying pathogenic variants in KIF5A were also described. LoF variants were identified only in the probands of two families with FALS, both of which were 3' splice-site variants leading to exon skipping and an altered C-terminal domain, located in the mutational hotspot causing FALS, and were considered to be pathogenic for FALS. Rare missense variants in KIF5A were identified in five patients with SALS (1.13%) and 11 control subjects (0.95%, carrier frequency), which were not significantly different. Consequently, the pathogenic LoF variants in KIF5A accounted for 2.1% of all FALS families in this study. These patients suffered from ALS characteristically associated with the predominant involvement of upper motor neuron. In conclusion, we identified two pathogenic splice-site variants in KIF5A in the probands in two Japanese families with FALS, which altered the C-terminal region of KIF5A. Our findings broaden the phenotype spectrum of ALS associated with variants in KIF5A in the Japanese series.

Effect of the Thermal Boundary Resistance in Metal/Dielectric Thermally Conductive Layers on Power Generation of Silicon Nanowire Microthermoelectric Generators

In microthermoelectric generators (μTEGs), parasitic thermal resistance must be suppressed to increase the temperature difference across thermocouples for optimum power generation. A thermally conductive (TC) layer is typically used in μTEGs to guide the heat flow from the heat source to the hot junction of each thermocouple. In this study, we investigate the effect of the thermal boundary resistance (TBR) in metal/dielectric TC layers on the power generation of silicon nanowire (SiNW) μTEGs. We prepared various metal/adhesion/dielectric TC layers using different metal, adhesion, and dielectric layers and measured the thermal resistance using the frequency-domain thermoreflectance method. We found that the thermal resistance was significantly different, mainly due to the TBR of the metal/dielectric interfaces. Interface characterization highlights the significant role of the interfacial bonding strength and interdiffusion in TBR. We fabricated a prototype SiNW-μTEG with different TC layers for testing, finding that the power generation increased significantly when the thermal resistance of the TC layer was lowered. This study helps to understand the underlying physics of thermal transport at interfaces and provides a guideline for the design and fabrication of μTEGs to enhance power generation for effective energy harvesting.

Effect of Thermal Boundary Resistance between the Interconnect Metal and Dielectric Interlayer on Temperature Increase of Interconnects in Deeply Scaled VLSI

Temperature increase in the continuously narrowing interconnects accelerates the performance and reliability degradation of very large scale integration (VLSI). Thermal boundary resistance (TBR) between an interconnect metal and dielectric interlayer has been neglected or treated approximately in conventional thermal analyses, resulting in significant uncertainties in performance and reliability. In this study, we investigated the effects of TBR between an interconnect metal and dielectric interlayer on temperature increase of Cu, Co, and Ru interconnects in deeply scaled VLSI. Results indicate that the measured TBR is significantly higher than the values predicted by the diffuse mismatch model and varies widely from 1 × 10^-8 to 1 × 10^-7 m² K W^-1 depending on the liner/barrier layer used. Finite element method simulations show that such a high TBR can cause a temperature increase of hundreds of degrees in the future VLSI interconnect. Characterization of interface properties shows the significant importance of interdiffusion and adhesion in TBR. For future advanced interconnects, Ru is better than Co for heat dissipation in terms of TBR. This study provides a guideline for the thermal management in deeply scaled VLSI.

Anesthetic management of a child with catecholaminergic polymorphic ventricular tachycardia undergoing insertion of implantable cardioverter defibrillator : a case report

Background

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a fatal cardiac ion channelopathy that causes sudden unexpected death in the young.

Case presentation

The patient was a 3-year-old girl with CPVT. Insertion of an implantable cardioverter defibrillator (ICD) using epicardial pacing was scheduled. After premedication of rectal midazolam was given, general anesthesia was induced with midazolam, fentanyl, and rocuronium, and maintained with midazolam, fentanyl, remifentanil, and rocuronium. The operation was performed without any complications. Dexmedetomidine and fentanyl were continuously infused after the operation until she was extubated in the morning of postoperative day 1. Fatal arrhythmia due to perioperative stress did not occur.

Conclusions

We report the anesthetic management of a child with CPVT who underwent insertion of an ICD. CPVT-induced fatal arrhythmia did not occur perioperatively by carefully avoiding perioperative stress with premedication and post-operative sedation.

Effects of β1-adrenergic receptor blockade on the cerebral microcirculation in the normal state and during global brain ischemia/reperfusion injury in rabbits

Background

Although recent studies using experimental models of ischemic brain injury indicate that systemically-administered β₁-blockers have potential protective effects on the cerebrovascular system, the precise mechanisms remain unclear. In addition to their cardiovascular effects, water-soluble β₁-blockers can pass the blood–brain barrier and may exert their vascular action on cerebral microvessels. The aim of this study was to investigate the direct effects of β₁-blockade on the cerebral microvasculature both in the normal state and ischemia/reperfusion state using the cranial window method.

Methods

The closed cranial window method was used to visualize the cerebral microcirculation and changes in the pial arteriole diameter in adult male rabbits. In the first experiment, various concentrations of the selective β₁-blocker landiolol were administered into the cranial window to evaluate the dose-response. In the second experiment, the effect of β₁-blockade on the brain during ischemic/reperfusion injury was investigated. Global brain ischemia/reperfusion was induced by clamping the brachiocephalic, left common carotid, and left subclavian arteries for 15 min. Either landiolol or artificial cerebrospinal fluid was infused 5 min after initiation of ischemia through 120 min after reperfusion. Pial arteriole diameter and hemodynamic and physiological parameters were recorded before ischemia, during ischemia, and 5, 10, 20, 40, 60, 80, 100, and 120 min after reperfusion.

Results

In the first experiment, topical administration of landiolol at higher concentrations produced slight pial arteriole dilation (10^− 8 mol/L: 4.3 ± 3.4%, 10^− 6 mol/L: 8.0 ± 5.8%, 10^− 4 mol/L: 7.3 ± 4.0%). In the second experiment, the topical administration of landiolol significantly dilated the pial arteriole diameters during ischemia/reperfusion injury (ischemia: 30.6 ± 38.6%, 5 min: 47.3 ± 42.2%, 10 min: 47.8 ± 34.2%, 20 min: 38.0 ± 39.0%). There were no statistical differences in hemodynamic and physiological parameters between the landiolol and control groups.

Conclusions

The blockade of β₁-adrenergic receptors induced significant vasodilation of pial arterioles during ischemia/reperfusion injury. By contrast, only a slight dilation of the arterioles was observed in the normal state, indicating that ischemic cerebral microvessels are more susceptible to the vasodilatory effect induced by selective blockade of β₁-adrenergic receptors than normal microvessels.

Clinical efficacy of haematopoietic stem cell transplantation for adult adrenoleukodystrophy

Accumulated experience supports the efficacy of allogenic haematopoietic stem cell transplantation in arresting the progression of childhood-onset cerebral form of adrenoleukodystrophy in early stages. For adulthood-onset cerebral form of adrenoleukodystrophy, however, there have been only a few reports on haematopoietic stem cell transplantation and the clinical efficacy and safety of that for adulthood-onset cerebral form of adrenoleukodystrophy remain to be established. To evaluate the clinical efficacy and safety of haematopoietic stem cell transplantation, we conducted haematopoietic stem cell transplantation on 12 patients with adolescent-/adult-onset cerebral form/cerebello-brainstem form of adrenoleukodystrophy in a single-institution-based prospective study. Through careful prospective follow-up of 45 male adrenoleukodystrophy patients, we aimed to enrol patients with adolescent-/adult-onset cerebral form/cerebello-brainstem form of adrenoleukodystrophy at early stages. Indications for haematopoietic stem cell transplantation included cerebral form of adrenoleukodystrophy or cerebello-brainstem form of adrenoleukodystrophy with Loes scores up to 13, the presence of progressively enlarging white matter lesions and/or lesions with gadolinium enhancement on brain MRI. Clinical outcomes of haematopoietic stem cell transplantation were evaluated by the survival rate as well as by serial evaluation of clinical rating scale scores and neurological and MRI findings. Clinical courses of eight patients who did not undergo haematopoietic stem cell transplantation were also evaluated for comparison of the survival rate. All the patients who underwent haematopoietic stem cell transplantation survived to date with a median follow-up period of 28.6 months (4.2–125.3 months) without fatality. Neurological findings attributable to cerebral/cerebellar/brainstem lesions became stable or partially improved in all the patients. Gadolinium-enhanced brain lesions disappeared or became obscure within 3.5 months and the white matter lesions of MRI became stable or small. The median Loes scores before haematopoietic stem cell transplantation and at the last follow-up visit were 6.0 and 5.25, respectively. Of the eight patients who did not undergo haematopoietic stem cell transplantation, six patients died 69.1 months (median period; range 16.0–104.1 months) after the onset of the cerebral/cerebellar/brainstem lesions, confirming that the survival probability was significantly higher in patients with haematopoietic stem cell transplantation compared with that in patients without haematopoietic stem cell transplantation (P = 0.0089). The present study showed that haematopoietic stem cell transplantation was conducted safely and arrested the inflammatory demyelination in all the patients with adolescent-/adult-onset cerebral form/cerebello-brainstem form of adrenoleukodystrophy when haematopoietic stem cell transplantation was conducted in the early stages. Further studies are warranted to optimize the procedures of haematopoietic stem cell transplantation for adolescent-/adult-onset cerebral form/cerebello-brainstem form of adrenoleukodystrophy.

Amiodarone exacerbates brain injuries after hypoxic-ischemic insult in mice

Background

Sodium ion transportation plays a crucial role in the pathogenesis of hypoxic–ischemic brain injury. Amiodarone, a Vaughan-Williams class III antiarrhythmic drug, has been widely used to treat life-threatening arrhythmia and cardiac arrest worldwide. In addition to its inhibitory effects on the potassium channel, amiodarone also blocks various sodium ion transporters, including the voltage-gated sodium channel, sodium pump, and Na⁺/Ca⁺ exchanger. Considering these pharmacological profile, amiodarone may affect the influx–efflux balance of sodium ion in the hypoxic–ischemic brain. Previous studies suggest that the blockade of the voltage-gated sodium channel during hypoxic–ischemic brain injury exerts neuroprotection. On the contrary, the blockade of sodium pump or Na⁺/Ca⁺ exchanger during hypoxia–ischemia may cause further intracellular sodium accumulation and consequent osmotic cell death. From these perspectives, the effects of amiodarone on sodium ion balance on the hypoxic–ischemic brain can be both protective and detrimental depending on the clinical and pathophysiological conditions. In this study, we therefore investigated the effect of amiodarone on hypoxic–ischemic brain injury using a murine experimental model.

Results

Compared with the control group mice, mice that received amiodarone after induction of 40-min hypoxic–ischemic brain injury exhibited lower survival rates over 7 days and worse neurological function. After 25-min hypoxic–ischemic brain injury, amiodarone treated mice exhibited larger infarct volumes (16.0 ± 6.9 vs. 24.2 ± 6.8 mm³, P < 0.05) and worse neurological function. In addition, the brains harvested from the amiodarone-treated mice contained larger amounts of sodium (194.7 ± 45.1 vs. 253.5 ± 50.9 mEq/kg dry weight, P < 0.01) and water (259.3 ± 8.9 vs. 277.2 ± 12.5 mg, P < 0.01). There were no significant differences in hemodynamic parameters between groups.

Conclusions

Amiodarone exacerbated brain injuries and neurological outcomes after hypoxic–ischemic insults. Severe brain sodium accumulation and brain edema were associated with the detrimental effects of amiodarone. Amiodarone at the clinical dose can exacerbate brain injury after hypoxic–ischemic insult by affecting sodium ion transportation and facilitate intracellular sodium accumulation in the brain.

Assessment of the potential for pathogen dispersal during high-flow nasal therapy

High-flow nasal therapy is increasingly used in hospitals because of its effectiveness and patient comfort. However, pathogens in the patient's nasal and oral cavities may be dispersed by forced air. This study aimed to investigate the risk of pathogen dispersal during high-flow nasal therapy. Liquid and bacterial dispersal were assessed via in-vitro experimental set-ups using a manikin. Thickened water or fresh yeast solution mimicked saliva and nasal mucus secretions. Dispersal was limited to the proximal area of the face and nasal cannula, suggesting that high-flow nasal therapy does not increase the risk of droplet and contact infection.

Prominent Spasticity and Hyperreflexia of the Legs in a Nepalese Patient with Friedreich Ataxia

Friedreich ataxia (FRDA) is an autosomal recessive spinocerebellar ataxia caused by mutations of FXN. Hypotonus and hyporeflexia of the lower extremities are observed in most FRDA patients. Patients with hyperreflexia, called Friedreich ataxia with retained reflexes (FARR), have also been identified. We herein report the case of a 16-year-old Nepalese boy presenting with early-onset ataxia with prominent spasticity and hyperreflexia of the legs. Mutational analyses established the diagnosis of FRDA presenting as FARR. A haplotype analysis revealed that expanded alleles of the patient shared a common haplotype with Indian and European FRDA patients, suggesting that the mutation descended from a common founder.

Prediction of heparin induced hypotension during cardiothoracic surgery: A retrospective observational study

Background: High-dose heparin occasionally causes severe hypotension during cardiothoracic surgery. Being able to predict the severity of the decrease in blood pressure prior to administration of heparin would improve hemodynamic and anesthetic management. The aim of this study was to investigate the predictors of heparininduced hypotension and the effects of high-dose heparin on various hemodynamic and physiologic parameters.Methodology: The records of adult patients who underwent elective cardiothoracic surgery at University of Yamanashi Hospital between January 2016 and December 2017 were retrospectively reviewed. Single and multiple linear regression analyses were conducted to identify the predictors of heparin-induced hypotension. Results: High baseline systemic vascular resistance index (SVRI) and non-use of preoperative antihypertensive medication were significant predictors of heparininduced hypotension with a following regression equation: Percent change in mean arterial pressure = 17.273 + 0.00457 × (baseline SVRI) - 14.043 × (antihypertensive medication), where antihypertensive medication is coded as 0 = no antihypertensive drug and 1 = one or more antihypertensive drug(s), F = 7.80, the multiple correlation coefficient is 0.68645, and R adjusted for degrees of freedom is 0.41078.Conclusion: The baseline SVRI and non-use of preoperative antihypertensive medication are significant predictors of the severity of heparin-induced hypotension.Abbreviations: MAP - Mean arterial blood pressure; CVP - central venous pressure; PAP - pulmonary arterial pressure; SVRI - systemic vascular resistance index; BMI: body mass index; ASA-PS: American Society of Anesthesiologists physical status classification; DM: diabetes mellitus; eGFR: estimated glomerular filtration rate; LVEF: left ventricular ejection fraction; EDVI: end-diastolic volume index; CI: cardiac index; SvO2: mixed venous oxygen saturation; LVEF: left ventricular ejection fraction; HR: heart rate. Preregistration: The study was approved by the institutional review board of University of Yamanashi (study H30036, registered May 28, 2018).Citation: Kotoda M, Ishiyama T, Nakajima H, Matsukawa T. Prediction of heparin induced hypotension during cardiothoracic surgery: A retrospective observational study. Anaesth pain & intensiv care 2019;23(2):145-150

Severe hypoglycemia reduces the shivering threshold in rabbits

Background

We previously reported that each 100 mg dL^− 1 reduction in blood glucose over the range from ≈90 to > 300 mg dL^− 1 decreases the shivering threshold (triggering core temperature) in rabbits by 1 °C. However, the effects of lower blood glucose concentrations has yet to be evaluated. We thus evaluated the relationship between the shivering threshold and blood glucose concentration over the mild-to-severe hypoglycemic range.

Methods

Thirty-nine rabbits were lightly anaesthetized with isoflurane and randomly assigned to one of the three groups: 1) severe hypoglycemia, insulin and dextrose infusions titrated to achieve blood glucose concentration at 45–75 mg dL^− 1; 2) mild hypoglycemia, insulin and dextrose infusions titrated to achieve blood glucose concentration at 75–100 mg dL^− 1; and 3) saline infusion. Cooling by colonic perfusion of water at 10 °C was continued until shivering occurred or esophageal core temperatures reached to 34 °C.

Results

The shivering threshold in the severe hypoglycemic rabbits was 35.7 ± 1.1 °C (mean ± SD); the thresholds in the mild hypoglycemic rabbits was 37.0 ± 0.7 °C; and the threshold in the control rabbits was 37.9 ± 1.0 °C. The shivering threshold increased linearly with blood glucose concentration: shivering threshold (°C) = 0.032 ∙ [blood glucose concentration (mg dL^− 1)] + 34.1, R² = 0.45. The shivering threshold thus decreased by approximately 1 °C for each 31 mg dL^− 1 decrease in blood glucose concentration.

Conclusions

There was a linear relationship between blood glucose and the shivering threshold over the range from severe hypoglycemia to normoglycemia. Blood glucose perturbations in the hypoglycemic range reduced the shivering threshold about three times as much as previously reported for the hyperglycemic range.

Analgesic effects of amiodarone in mouse models of pain

Purpose: Although amiodarone is classified as a Vaughan-Williams class Ⅲ antiarrhythmic drug, it has inhibitory effects on voltage-gated sodium and calcium channels and on β-adrenergic receptors. Given these pharmacological profiles, amiodarone may have analgesic properties. Most patients who are prescribed amiodarone possess multiple cardiovascular risk factors. Despite the fact that pain plays a crucial role as a clinical indicator of cardiovascular events, the effects of amiodarone on pain have not been investigated. The aim of the current study was to investigate the analgesic effects of amiodarone by using mouse models of pain in an effort to elucidate underlying mechanisms. Methods: Adult male C57B6 mice received single bolus intraperitoneal injections of amiodarone at doses of 25, 50, 100, and 200 mg/kg, while the mice in the control group received only normal saline. The analgesic effects of amiodarone were evaluated using the acetic acid-induced writhing test, formalin test, and tail withdrawal test. In addition, the potassium channel opener NS1643, voltage-gated sodium channel opener veratrine, calcium channel opener BAYK8644, and selective β-adrenergic agonist isoproterenol were used to uncover the underlying mechanism. Results: During the acetic acid-induced writhing test, formalin test, and tail withdrawal test, amiodarone induced analgesic responses in a dose-dependent manner. The analgesic effects of amiodarone were abolished by veratrine but not by NS1643, BAYK8644, or isoproterenol. Conclusion: Amiodarone induced analgesic responses in a dose-dependent manner, likely by blocking voltage-gated sodium channels. These results indicate that clinical doses of amiodarone can affect nociception and may mask or attenuate pain induced by acute cardiovascular events.

Sudden onset pacemaker-induced diaphragmatic twitching during general anesthesia

BACKGROUND

Involuntary muscle contraction caused by extracardiac stimulation is a rare complication induced by a pacemaker. We report a case who developed sudden onset diaphragmatic contractions during general anesthesia caused by a DDD mode pacemaker.

CASE PRESENTATION

A 74-year-old woman with a permanent pacemaker was scheduled to undergo mastectomy. The pacing mode was switched from DDD to VOO intraoperatively to avoid electromagnetic interference. Immediately after returning the pacing mode to DDD after surgery, diaphragmatic contractions occurred, mimicking bucking type of movements. After switching the pacing to A-sense V-pace, the twitching ceased. Because no structural problems were noted, and the twitching disappeared after terminating atrial pacing, diaphragmatic contractions might be caused by stimulation of the right phrenic nerve located near the right appendage where the electrode was installed.

CONCLUSION

The potential risk of muscle twitching should be carefully evaluated preoperatively especially in patients with atypical position of pacemaker leads.