A case of afterload mismatch associated with shivering leading to fatal hypoxia in a COVID-19 patient

Background

Fever and associated shivering are frequent symptoms in patients with coronavirus disease 2019 (COVID-19). High body temperature activates the immune system, which might be beneficial. However, shivering leads to high oxygen demand.

Case presentation

A 38-year-old man diagnosed with COVID-19 was transferred to our intensive care unit (ICU). His oxygen saturation (SpO2) level was approximately 92–95% and was managed with a high flow nasal cannula. Six hours after admission to the ICU, he started shivering, and his systolic blood pressure rose above 200 mmHg. Concomitantly, his SpO2 levels decreased rapidly. Mechanical ventilation was started, but oxygenation could not be maintained, requiring the establishment of extracorporeal membrane oxygenation (ECMO).

Conclusions

COVID-19 is known to cause thrombosis in the pulmonary microvasculature at the early stage of the disease. Under these circumstances, caution should be paid since shivering may worsen the patient’s condition.

A case of refractory pneumothorax and contralateral atelectasis after thoracoscopic subtotal esophagectomy treated with independent lung ventilation

Background

Independent lung ventilation (ILV) allows separate positive end-expiratory pressures (PEEP) and inspiratory pressures for each lung. However, only a few articles have reported ILV management for lungs affected by different pathologies.

Case presentation

A 56-year-old man underwent video-assisted thoracic surgery for esophageal cancer. The right lung was injured during surgery, causing a bronchopleural fistula and necessitating chest drainage. On the third day in the intensive care unit, the patient’s oxygenation worsened during pressure support with continuous positive airway pressure ventilation. ILV was initiated for right-sided severe pneumothorax and left-sided atelectasis and pneumonia. ILV was continued for 2 days, and the patient’s trachea was successfully extubated the following day.

Conclusion

Applying high-level PEEP to the one lung and minimizing the airway pressure on the other lung could be achieved using ILV, which might contribute to successful tracheal extubation.

Current Status of Clinical Engineer Anesthesia Assistants and Their Effect on Labor Task Shifting in Japan: A Prospective Observational Study in a Single Institute

Introduction:

Anesthesiologists are in short supply across the world, resulting in perpetually long working hours. To reduce the burden on anesthesiologists, tasks that can be performed by non-physicians must be shifted to other medical staff. In hospitals, clinical engineers can work as anesthesia assistants and perform some of the duties of anesthesiologists. This study aimed to evaluate the effect of task shift performed by clinical engineer anesthesia assistants (CEAAs).

Methods:

This was a 1-month prospective observational study that included 33 anesthesiologists (11 fellows and 22 certified anesthesiologists) and 11 CEAAs. The total activity and anesthesia times were extracted from the attendance record as indices of the anesthesiologists' work status. The CEAAs recorded the duration of work performed on behalf of the anesthesiologists as task shift time. The task shift rate was evaluated as follows: task shift time/(task shift time + total activity time) and task shift time/(task shift time) + (total anesthesia time).

Results:

The study period consisted of 19 weekdays. The average daily activity time of the anesthesiologists was 10.1 h, and the average anesthesia time was 8.5 h. The CEAAs performed a total of 546.8 h of task shift. The defined task shift rate was 20.1% when the total activity time was the denominator and 23.1% when the anesthesia time was the denominator.

Conclusions:

CEAAs might be effective in reducing the working hours of anesthesiologists through task shift. Their taking over a portion of the anesthesiologists' duties may allow the anesthesiologists to work more efficiently.

Life-threatening airway obstruction caused by angioedema in a morbidly obese postoperative patient: a case report

Background

We report a case of a morbidly obese patient who developed life-threatening airway obstruction due to angioedema.

Case presentation

A 50-year-old Japanese morbidly obese female was treated with enalapril for 10 years, with no history of angioedema. After 3 h of completion of breast cancer resection under general anesthesia with tracheal intubation, she developed airway obstruction and respiratory arrest. Her oral cavity was occupied with a swollen tongue. It was extremely difficult to determine the airway anatomical orientation although tracheal intubation was attempted using a videolaryngoscope. At this time, she probably started gasping respiration, which generated a faint bubble and revealed a possible airway. Her airway was established using a tracheal tube without confirming the glottis or the vocal cord.

Conclusions

Angioedema induced by angiotensin-converting enzyme (ACE) inhibitors is rare; however, once it occurs, it can be potentially life threatening, especially for patients with possible difficult airway. Considering the risk–benefit ratio, we must be careful in administering ACE inhibitor therapy in morbidly obese patients.

A case of subcutaneous emphysema/mediastinal emphysema during the use of humidified high-flow nasal cannula

Background

Heated, humidified, high-flow nasal cannula (HHFNC) oxygen therapy allows optimal humidification of inspired gas at high flows and creates a distending pressure similar to nasal continuous positive airway pressure [1]. It has been safely used in adults with moderate hypoxemia with few complications [2, 3]. Hereby, we report serious complications occurred during HHFNC oxygen therapy.

Case presentation

A 53-year-old female with hemophagocytic lymphohistiocytosis (HLH) was admitted to the intensive care unit because of respiratory failure. After weaning from mechanical ventilation which lasted for 2 weeks, HHFNC therapy at 40 L/min with an FiO2 of 0.5 was started for hypoxemia. Four days later, dyspnea and hypoxemia occurred and chest X-ray and CT scan revealed localized pneumothorax, subcutaneous emphysema, and massive pneumomediastinum. After cessation of HHFNC, respiratory condition improved.

Conclusion

Subcutaneous emphysema, pneumothorax, and pneumomediastinum should be notified as a serious complication during HHFNC therapy.

Neuron-Targeted Caveolin-1 Promotes Ultrastructural and Functional Hippocampal Synaptic Plasticity

A delicate interneuronal communication between pre- and postsynaptic membranes is critical for synaptic plasticity and the formation of memory. Evidence shows that membrane/lipid rafts (MLRs), plasma membrane microdomains enriched in cholesterol and sphingolipids, organize presynaptic proteins and postsynaptic receptors necessary for synaptic formation and signaling. MLRs establish a cell polarity that facilitates transduction of extracellular cues to the intracellular environment. Here we show that neuron-targeted overexpression of an MLR protein, caveolin-1 (SynCav1), in the adult mouse hippocampus increased the number of presynaptic vesicles per bouton, total excitatory type I glutamatergic synapses, number of same-dendrite multiple-synapse boutons, increased myelination, increased long-term potentiation, and increased MLR-localized N-methyl-d-aspartate receptor subunits (GluN1, GluN2A, and GluN2B). Immunogold electron microscopy revealed that Cav-1 localizes to both the pre- and postsynaptic membrane regions as well as in the synaptic cleft. These findings, which are consistent with a significant increase in ultrastructural and functional synaptic plasticity, provide a fundamental framework that underlies previously demonstrated improvements in learning and memory in adult and aged mice by SynCav1. Such observations suggest that Cav-1 and MLRs alter basic aspects of synapse biology that could serve as potential therapeutic targets to promote neuroplasticity and combat neurodegeneration in a number of neurological disorders.

Neuron-targeted caveolin-1 improves neuromuscular function and extends survival in SOD1G93A mice

Interventions that preserve motor neurons or restore functional motor neuroplasticity may extend longevity in amyotrophic lateral sclerosis (ALS). Delivery of neurotrophins may potentially revive degenerating motor neurons, yet this approach is dependent on the proper subcellular localization of neurotrophin receptor (NTR) to plasmalemmal signaling microdomains, termed membrane/lipid rafts (MLRs). We previously showed that overexpression of synapsin-driven caveolin-1 (Cav-1) (SynCav1) increases MLR localization of NTR [e.g., receptor tyrosine kinase B (TrkB)], promotes hippocampal synaptic and neuroplasticity, and significantly improves learning and memory in aged mice. The present study crossed a SynCav1 transgene-positive (SynCav1⁺) mouse with the mutant human superoxide dismutase glycine to alanine point mutation at amino acid 93 (hSOD1^G93A) mouse model of ALS. When compared with hSOD1^G93A, hSOD1^G93A/SynCav1⁺ mice exhibited greater body weight and longer survival as well as better motor function. Microscopic analyses of hSOD1^G93A/SynCav1⁺ spinal cords revealed preserved spinal cord α-motor neurons and preserved mitochondrial morphology. Moreover, hSOD1^G93A/SynCav1⁺ spinal cords contained more MLRs (cholera toxin subunit B positive) and MLR-associated TrkB and Cav-1 protein expression. These findings demonstrate that SynCav1 delays disease progression in a mouse model of ALS, potentially by preserving or restoring NTR expression and localization to MLRs.-Sawada, A., Wang, S., Jian, M., Leem, J., Wackerbarth, J., Egawa, J., Schilling, J. M., Platoshyn, O., Zemljic-Harpf, A., Roth, D. M., Patel, H. H., Patel, P. M., Marsala, M., Head, B. P. Neuron-targeted caveolin-1 improves neuromuscular function and extends survival in SOD1^G93A mice.

Risk factors for bradypnea in a historical cohort of surgical patients receiving fentanyl-based intravenous analgesia

Introduction

The use of both pulse oximetry (SpO₂) and respiration rate (RR) monitoring is recommended to prevent the development of respiratory deterioration, particularly after extubation and narcotic analgesic use for pain management. In this study, we investigated the factors contributing to the development of bradypnea in surgical patients receiving fentanyl-based intravenous analgesia after general anesthesia.

Methods

This study involved a historical chart review of postoperative patients outside an intensive care unit setting. We divided the patients according to the data collected during the first hour postoperatively, into those developing bradypnea (RR < 8 breaths per min for > 2 min) and those with normal RR under oxygen administration. We defined oxygen desaturation as SpO₂ < 90% for > 10 s. We calculated the effect-site concentrations for fentanyl at the end of surgery and 1 h postoperatively using custom-made software based on chart records. A multivariable analysis was used to determine bradypnea-associated explanatory factors.

Results

For the final analysis, we included 258 patients. We detected bradypnea in 125 patients (48%) and oxygen desaturation in 46 patients (18%). We found no difference in the effect-site fentanyl concentrations between patients with and without bradypnea. The logistic regression model revealed that liver dysfunction [odds ratio (OR), 2.918; 95% confidence interval (CI), 1.329–6.405], renal dysfunction (OR, 0.349; 95% CI, 0.128–0.955), and smoking history (OR, 0.236; 95% CI, 0.075–0.735) were independently associated with bradypnea. We found similar incidences of oxygen desaturation between the groups.

Conclusions

Bradypnea was observed in 48% of postoperative patients receiving fentanyl-based intravenous analgesia under oxygen therapy. According to our results, impaired liver function associated positively, whereas smoking history associated negatively with its development. Renal dysfunction was paradoxically associated with less incidence of bradypnea.

Inhibition of RhoA reduces propofol-mediated growth cone collapse, axonal transport impairment, loss of synaptic connectivity, and behavioural deficits

BACKGROUND

Exposure of the developing brain to propofol results in cognitive deficits. Recent data suggest that inhibition of neuronal apoptosis does not prevent cognitive defects, suggesting mechanisms other than neuronal apoptosis play a role in anaesthetic neurotoxicity. Proper neuronal growth during development is dependent upon growth cone morphology and axonal transport. Propofol modulates actin dynamics in developing neurones, causes RhoA-dependent depolymerisation of actin, and reduces dendritic spines and synapses. We hypothesised that RhoA inhibition prevents synaptic loss and subsequent cognitive deficits. The present study tested whether RhoA inhibition with the botulinum toxin C3 (TAT-C3) prevents propofol-induced synapse and neurite loss, and preserves cognitive function.

METHODS

RhoA activation, growth cone morphology, and axonal transport were measured in neonatal rat neurones (5-7 days in vitro) exposed to propofol. Synapse counts (electron microscopy), dendritic arborisation (Golgi-Cox), and network connectivity were measured in mice (age 28 days) previously exposed to propofol at postnatal day 5-7. Memory was assessed in adult mice (age 3 months) previously exposed to propofol at postnatal day 5-7.

RESULTS

Propofol increased RhoA activation, collapsed growth cones, and impaired retrograde axonal transport of quantum dot-labelled brain-derived neurotrophic factor, all of which were prevented with TAT-C3. Adult mice previously treated with propofol had decreased numbers of total hippocampal synapses and presynaptic vesicles, reduced hippocampal dendritic arborisation, and infrapyramidal mossy fibres. These mice also exhibited decreased hippocampal-dependent contextual fear memory recall. All anatomical and behavioural changes were prevented with TAT-C3 pre-treatment.

CONCLUSION

Inhibition of RhoA prevents propofol-mediated hippocampal neurotoxicity and associated cognitive deficits.

Incidence of life-threatening respiratory events after laparoscopic colon surgery with or without continuous respiratory rate monitoring

Background

Respiratory depression (RD) is a critical complication of general anesthesia. The present study investigated the incidence of postoperative life-threatening respiratory events after laparoscopic colon surgery in patients observed using continuous respiratory rate monitoring [RM; with oxygen saturation by pulse oximetry (SpO₂)] and traditional respiratory monitoring (TM; SpO₂ monitoring only). In addition, postoperative incidence rates of RD and desaturation in the RM group were determined.

Findings

In this retrospective observational study, medical records of 214 patients who underwent laparoscopic colon surgery were analyzed. A total of 88 patients with RM were observed and compared with 126 patients with TM. Nineteen patients in the RM group were excluded from the final analyses because of incomplete data. No life-threatening respiratory events were observed in the RM group (0/69), whereas two such events (2/126) occurred in the TM group. Incidence rates of postoperative RD and desaturation within 8 h after surgery were 17.1% (12/69) and 24.3% (17/69), respectively, in the RM group.

Conclusions

No postoperative life-threatening respiratory events were observed in the RM group. Furthermore, the incidence rates of RD and desaturation were noted to be relatively high.

A pediatric case developing critical abdominal distension caused by a combination of humidified high-flow nasal cannula oxygen therapy and nasal airway

Background

We describe a pediatric patient who suffered from critical abdominal distention caused by a combination of humidified, high-flow nasal cannula (HHFNC) oxygen therapy and nasal airway.

Case presentation

A 21-month-old boy with a history of chronic lung disease was admitted to the intensive care unit (ICU). Immediately after admission, his airway was established using a tracheal tube and mechanical ventilation was started. Five days after the commencement of mechanical ventilation, finally, his trachea was extubated. Immediately after extubation, HHFNC therapy at 20 L/min with an FiO₂ of 0.35 was applied. However, severe stridor was observed, then a nasal airway was placed in the left nostril. However, he became restless. Critical abdominal distention was observed. A subsequent chest X-ray revealed that the nasal airway was placed too deeply, and the gastrointestinal air was severely accumulated. Immediately, the nasal airway was removed, and HHFNC flow was reduced to 10 L/min. Frequent suctioning and continuous gastric drainage were required, which achieved gradual improvement of respiratory condition.

Conclusions

We need to recognize that HHFNC therapy is one of the positive pressure ventilation system. Therefore, HHFNC therapy might cause the similar adverse events to noninvasive pressure ventilation.

Effects of deep sedation under mechanical ventilation on cognitive outcome in patients undergoing surgery for oral and maxillofacial cancer and microvascular reconstruction

OBJECTIVE

Cognitive impairment after intensive care unit (ICU) admission is becoming increasingly recognized. High-dose deep sedation has been suggested to play an important role in the development of cognitive impairment. However, the impact of heavy sedation as a single cause in the development of cognitive impairment in ICU patients remains unclear. In this study we investigated whether a three-day deep sedation protocol could reduce cognitive function in mechanically ventilated non-critical patients.

DESIGN

A prospective observational study was carried out.

PATIENTS

A total of 17 surgical patients were studied.

INTERVENTION

None.

VARIABLES OF INTEREST

Cognitive function before and after ICU admission.

RESULTS

Thirty-one patients requiring three days of sedation after microvascular reconstruction were initially enrolled in the study. Sedation in the ICU was maintained with propofol and dexmedetomidine combined with fentanyl. Cognitive function was assessed using a battery of 6 neuropsychological tests two days before surgery and three weeks after surgery. Finally, a total of 17 patients were included in the analysis. Cognitive impairment (defined as a decline of >20% from the pre-admission cognitive evaluation scores in at least two of 6 tests) was observed in 5 of the 17 patients (29%). However, there were no significant differences between the pre- and post-admission cognitive evaluations in 6 tests.

CONCLUSIONS

Middle-term cognitive function can be impaired in some patients subjected to deep sedation during several days following maxillary-mandibular oral surgery with microvascular reconstruction.

Rare genetic variants in CX3CR1 and their contribution to the increased risk of schizophrenia and autism spectrum disorders

CX3CR1, a G protein-coupled receptor solely expressed by microglia in the brain, has been repeatedly reported to be associated with neurodevelopmental disorders including schizophrenia (SCZ) and autism spectrum disorders (ASD) in transcriptomic and animal studies but not in genetic studies. To address the impacts of variants in CX3CR1 on neurodevelopmental disorders, we conducted coding exon-targeted resequencing of CX3CR1 in 370 Japanese SCZ and 192 ASD patients using next-generation sequencing technology, followed by a genetic association study in a sample comprising 7054 unrelated individuals (2653 SCZ, 574 ASD and 3827 controls). We then performed in silico three-dimensional (3D) structural modeling and in vivo disruption of Akt phosphorylation to determine the impact of the detected variant on CX3CR1-dependent signal transduction. We detected a statistically significant association between the variant Ala55Thr in CX3CR1 with SCZ and ASD phenotypes (odds ratio=8.3, P=0.020). A 3D structural model indicated that Ala55Thr could destabilize the conformation of the CX3CR1 helix 8 and affect its interaction with a heterotrimeric G protein. In vitro functional analysis showed that the CX3CR1-Ala55Thr mutation inhibited cell signaling induced by fractalkine, the ligand for CX3CR1. The combined data suggested that the variant Ala55Thr in CX3CR1 might result in the disruption of CX3CR1 signaling. Our results strengthen the association between microglia-specific genes and neurodevelopmental disorders.

Pathophysiology Associated with Traumatic Brain Injury: Current Treatments and Potential Novel Therapeutics

Traumatic brain injury (TBI) is one of the leading causes of death of young people in the developed world. In the United States alone, 1.7 million traumatic events occur annually accounting for 50,000 deaths. The etiology of TBI includes traffic accidents, falls, gunshot wounds, sports, and combat-related events. TBI severity ranges from mild to severe. TBI can induce subtle changes in molecular signaling, alterations in cellular structure and function, and/or primary tissue injury, such as contusion, hemorrhage, and diffuse axonal injury. TBI results in blood-brain barrier (BBB) damage and leakage, which allows for increased extravasation of immune cells (i.e., increased neuroinflammation). BBB dysfunction and impaired homeostasis contribute to secondary injury that occurs from hours to days to months after the initial trauma. This delayed nature of the secondary injury suggests a potential therapeutic window. The focus of this article is on the (1) pathophysiology of TBI and (2) potential therapies that include biologics (stem cells, gene therapy, peptides), pharmacological (anti-inflammatory, antiepileptic, progrowth), and noninvasive (exercise, transcranial magnetic stimulation). In final, the review briefly discusses membrane/lipid rafts (MLR) and the MLR-associated protein caveolin (Cav). Interventions that increase Cav-1, MLR formation, and MLR recruitment of growth-promoting signaling components may augment the efficacy of pharmacologic agents or already existing endogenous neurotransmitters and neurotrophins that converge upon progrowth signaling cascades resulting in improved neuronal function after injury.

Neuron-specific caveolin-1 overexpression improves motor function and preserves memory in mice subjected to brain trauma

Studies in vitro and in vivo demonstrate that membrane/lipid rafts and caveolin (Cav) organize progrowth receptors, and, when overexpressed specifically in neurons, Cav-1 augments neuronal signaling and growth and improves cognitive function in adult and aged mice; however, whether neuronal Cav-1 overexpression can preserve motor and cognitive function in the brain trauma setting is unknown. Here, we generated a neuron-targeted Cav-1-overexpressing transgenic (Tg) mouse [synapsin-driven Cav-1 (SynCav1 Tg)] and subjected it to a controlled cortical impact model of brain trauma and measured biochemical, anatomic, and behavioral changes. SynCav1 Tg mice exhibited increased hippocampal expression of Cav-1 and membrane/lipid raft localization of postsynaptic density protein 95, NMDA receptor, and tropomyosin receptor kinase B. When subjected to a controlled cortical impact, SynCav1 Tg mice demonstrated preserved hippocampus-dependent fear learning and memory, improved motor function recovery, and decreased brain lesion volume compared with wild-type controls. Neuron-targeted overexpression of Cav-1 in the adult brain prevents hippocampus-dependent learning and memory deficits, restores motor function after brain trauma, and decreases brain lesion size induced by trauma. Our findings demonstrate that neuron-targeted Cav-1 can be used as a novel therapeutic strategy to restore brain function and prevent trauma-associated maladaptive plasticity.-Egawa, J., Schilling, J. M., Cui, W., Posadas, E., Sawada, A., Alas, B., Zemljic-Harpf, A. E., Fannon-Pavlich, M. J., Mandyam, C. D., Roth, D. M., Patel, H. H., Patel, P. M., Head, B. P. Neuron-specific caveolin-1 overexpression improves motor function and preserves memory in mice subjected to brain trauma.

Neuron-Targeted Caveolin-1 Improves Molecular Signaling, Plasticity, and Behavior Dependent on the Hippocampus in Adult and Aged Mice

BACKGROUND

Studies in vitro demonstrate that neuronal membrane/lipid rafts (MLRs) establish cell polarity by clustering progrowth receptors and tethering cytoskeletal machinery necessary for neuronal sprouting. However, the effect of MLR and MLR-associated proteins on neuronal aging is unknown.

METHODS

Here, we assessed the impact of neuron-targeted overexpression of an MLR scaffold protein, caveolin-1 (Cav-1) (via a synapsin promoter, SynCav1), in the hippocampus in vivo in adult (6-month-old) and aged (20-month-old) mice on biochemical, morphologic, and behavioral changes.

RESULTS

SynCav1 resulted in increased expression of Cav-1, MLRs, and MLR-localization of Cav-1 and tropomyosin-related kinase B receptor independent of age and time post gene transfer. Cav-1 overexpression in adult mice enhanced dendritic arborization within the apical dendrites of hippocampal cornu ammonis 1 and granule cell neurons, effects that were also observed in aged mice, albeit to a lesser extent, indicating preserved impact of Cav-1 on structural plasticity of hippocampal neurons with age. Cav-1 overexpression enhanced contextual fear memory in adult and aged mice demonstrating improved hippocampal function.

CONCLUSIONS

Neuron-targeted overexpression of Cav-1 in the adult and aged hippocampus enhances functional MLRs with corresponding roles in cell signaling and protein trafficking. The resultant structural alterations in hippocampal neurons in vivo are associated with improvements in hippocampal-dependent learning and memory. Our findings suggest Cav-1 as a novel therapeutic strategy in disorders involving impaired hippocampal function.

Caveolin-1 regulation of disrupted-in-schizophrenia-1 as a potential therapeutic target for schizophrenia

Schizophrenia is a debilitating psychiatric disorder manifested in early adulthood. Disrupted-in-schizophrenia-1 (DISC1) is a susceptible gene for schizophrenia (Hodgkinson et al. 2004; Millar et al. 2000; St Clair et al. 1990) implicated in neuronal development, brain maturation, and neuroplasticity (Brandon and Sawa 2011; Chubb et al. 2008). Therefore, DISC1 is a promising candidate gene for schizophrenia, but the molecular mechanisms underlying its role in the pathogenesis of the disease are still poorly understood. Interestingly, caveolin-1 (Cav-1), a cholesterol binding and scaffolding protein, regulates neuronal signal transduction and promotes neuroplasticity. In this study we examined the role of Cav-1 in mediating DISC1 expression in neurons in vitro and the hippocampus in vivo. Overexpressing Cav-1 specifically in neurons using a neuron-specific synapsin promoter (SynCav1) increased expression of DISC1 and proteins involved in synaptic plasticity (PSD95, synaptobrevin, synaptophysin, neurexin, and syntaxin 1). Similarly, SynCav1-transfected differentiated human neurons derived from induced pluripotent stem cells (hiPSCs) exhibited increased expression of DISC1 and markers of synaptic plasticity. Conversely, hippocampi from Cav-1 knockout (KO) exhibited decreased expression of DISC1 and proteins involved in synaptic plasticity. Finally, SynCav1 delivery to the hippocampus of Cav-1 KO mice and Cav-1 KO neurons in culture restored expression of DISC1 and markers of synaptic plasticity. Furthermore, we found that Cav-1 coimmunoprecipitated with DISC1 in brain tissue. These findings suggest an important role by which neuron-targeted Cav-1 regulates DISC1 neurobiology with implications for synaptic plasticity. Therefore, SynCav1 might be a potential therapeutic target for restoring neuronal function in schizophrenia.

NEW & NOTEWORTHY

The present study is the first to demonstrate that caveolin-1 can regulate DISC1 expression in neuronal models. Furthermore, the findings are consistent across three separate neuronal models that include rodent neurons (in vitro and in vivo) and human differentiated neurons derived from induced pluripotent stem cells. These findings justify further investigation regarding the modulatory role by caveolin on synaptic function and as a potential therapeutic target for the treatment of schizophrenia.

[The Implication of Dietary Supplements and Herbal Medicines in Perioperative Period]

Total sales of dietary supplements and herbal medi- cines exceed two trillion yen in Japan. Approximately 60% of Japanese use dietary supplements or herbal medicines. In general, many people believe that dietary supple- ments and herbal medicines are safe natural prod- ucts; however, they could induce serious adverse events (bleeding, myocardial infarction stroke and glucose intolerance) in perioperative period. Coagulation and cardiovascular system can be nega- tively affected by those products. Thus careful preop- erative assessment is required for the patients who need regional anesthesia (e.g. epidural anesthesia and spinal anesthesia) and have cardiovascular complica- tions. Unfortunately there is no concise guideline regarding the use of supplements and herbal medicines during perioperative period. Anesthesiologists should be familiar with the adverse effects of dietary supplements and herbal medicines and pay more attention to non-prescribed medicines in preoperative assessment.

Membrane lipid rafts and neurobiology: age-related changes in membrane lipids and loss of neuronal function

A better understanding of the cellular physiological role that plasma membrane lipids, fatty acids and sterols play in various cellular systems may yield more insight into how cellular and whole organ function is altered during the ageing process. Membrane lipid rafts (MLRs) within the plasma membrane of most cells serve as key organizers of intracellular signalling and tethering points of cytoskeletal components. MLRs are plasmalemmal microdomains enriched in sphingolipids, cholesterol and scaffolding proteins; they serve as a platform for signal transduction, cytoskeletal organization and vesicular trafficking. Within MLRs are the scaffolding and cholesterol binding proteins named caveolin (Cav). Cavs not only organize a multitude of receptors including neurotransmitter receptors (NMDA and AMPA receptors), signalling proteins that regulate the production of cAMP (G protein-coupled receptors, adenylyl cyclases, phosphodiesterases (PDEs)), and receptor tyrosine kinases involved in growth (Trk), but also interact with components that modulate actin and tubulin cytoskeletal dynamics (e.g. RhoGTPases and actin binding proteins). MLRs are essential for the regulation of the physiology of organs such as the brain, and age-related loss of cholesterol from the plasma membrane leads to loss of MLRs, decreased presynaptic vesicle fusion, and changes in neurotransmitter release, all of which contribute to different forms of neurodegeneration. Thus, MLRs provide an active membrane domain that tethers and reorganizes the cytoskeletal machinery necessary for membrane and cellular repair, and genetic interventions that restore MLRs to normal cellular levels may be exploited as potential therapeutic means to reverse the ageing and neurodegenerative processes.

Life-threatening airway obstruction due to upper airway edema and marked neck swelling after labor and delivery

BACKGROUND AND OBJECTIVES

Airway changes generally occur in normal gravidas; however, these changes could cause critical situations in specific populations.

OBJECTIVES

This article presents the case of a difficult airway patient that went into shock because of atonic bleeding after vaginal delivery for stillbirth.

CASE REPORT

A 32-yr-old woman with atonic bleeding after vaginal delivery for stillbirth was transferred to our hospital. She manifested shock, and her respiratory condition was progressively deteriorating. Airway obstruction caused by neck swelling and pharyngolaryngeal edema was apparent. We tried tracheal intubation using direct and indirect laryngoscopes. However, it turned out that insertion of the laryngoscopic devices to the oral cavity was impossible. After several attempts using the Trachlight™, successful intubation was finally made. After hysterectomy, she was admitted to the intensive care unit (ICU) and treated for five days. At discharge from the ICU, her Mallampati score was I-II. Her body weight decreased 60 kg to 51 kg during ICU stay.

CONCLUSIONS

We believe that concomitant attacks of labor and delivery and fluid resuscitation probably worsened upper airway and neck edema enough to cause acute airway obstruction and difficult laryngoscopy.

[Preoperative evaluation and prognosis of patients with cerebrovascular disease]

Stroke remains a major perioperative problem for anesthesiologists. In this article, we have described preoperative evaluation and prognosis of patients with cerebrovascular disease. Cerebral infarction accounts for more than 60% of stroke. In patients with recently developed ischemic stroke, a surgery should be delayed at least for a month. Carotid artery stenosis accounts for 15 to 20% of ischemic stroke. In these patients, since the incidence of cardiovascular disease is common, cardiovascular examinations may be required preoperatively. The efficacy of carotid endarterectomy (CEA) to prevent stroke is well established, whereas carotid artery stenting (CAS) has been increasingly advocated as less invasive treatment. Several studies have indicated that the risks of CAS are higher than those of CEA, suggesting that CAS may not be used in good surgical candidates. In the patients with subarachnoid hemorrhage (SAH), preoperative assessments of cardiac and respiratory condition are required. It is reported that unfavorable outcome after SAH is related to rebleeding and cerebral vasospasm.

Pulmonary hypertension due to unknown causes in liver resection

A 16-year-old male underwent transcatheter arterial embolization against a large hepatic tumor, and was subsequently scheduled for removal of the tumor. Sudden hypotension and tachycardia were observed on removal of the tumor. Massive bleeding or obstruction of the inferior vena cava was expected to develop, but this did not occur because of simultaneous pulmonary hypertension (PH). The development of acute PH due to pulmonary vasoconstriction was suspected. Milrinone and prostaglandin E1 were effective. The same type of PH was again observed during manipulation of the residual portion of the liver. The acute PH was reproducible each time the liver was manipulated, which could suggest that this series of PH was specifically related to the hepatic lesion. A necrotic hepatic lesion might play an important role in disturbing the pulmonary circulation and causing the development of acute PH.

[Four cases of diplopia following spinal anesthesia]

Many complications after spinal anesthesia have been reported, but diplopia is rare. We had four cases of diplopia in 794 cases of spinal anesthesia in three years at Nara Medical University Hospital. These 4 cases were not characterized by any major factors including gender, age, or anesthetic choice. However, two of them were accompanied with post-spinal headache. Diplopia in three cases improved spontaneously, but one finally required epidural blood patch for the persistent diplopia. Lack of concern regarding the possibility of post-spinal diplopia among medical staffs might be common because this incidence is really rare. However, we need to know the possibility of this neurological sequel after spinal anesthesia. We would like to propose that the informed consent regarding spinal anesthesia should include the possibility of this complication and anesthesiologists should perform intensive neurological examinations after spinal anesthesia concerning post-spinal diplopia.

[Present state of guidelines for perioperative management of deep vein thrombosis and pulmonary embolism in Japan]

To clarify the present state of local institutional guideline for perioperative deep thrombosis and pulmonary embolism in individual hospitals, a questionnaire was sent to anesthesia departments in Japan. According to the replies, 82 hospitals have original guidelines. Forty of them reported the contents of their guidelines. However, 37 hospitals have some problems regarding their guidelines. Cost for these perioperative managements and application of spinal or epidural anesthesia for heparinized patients appears to be commonly recognized as pending questions in their guideline. It seems to be difficult to make a stereotyped standard guideline in Japan because each local guideline has a specific strategy according to their situations. However, it is needless to say that a further nationwide survey and collaboration, and governmental support for these diseases would be required.

[Effect of porcine calcitonin on pain caused by cancer-induced bone destruction]

The analgesic effect of porcine calcitonin (PCT) was studied in 32 patients with cancer-induced bone destruction. Twenty patients (62.5%) showed some response among them 10 of 13 patients who had suffered from uncontrollable pain despite other treatment methods such as radiotherapy, and or the administration of other analgesics. The effect was observed about 10 days after the administration of the drug. Combined therapy with PCT and other modalities such as radiotherapy, chemotherapy and hormone therapy had a marked effect in controlling the pain.

[Fundamental and clinical studies on T-1982 (cefbuperazone) in the field of obstetrics and gynecology]

T-1982 (cefbuperazone), a new cephamycin antibiotic, was fundamentally and clinically studied in the field of obstetrics and gynecology. The following results were obtained. The concentrations of T-1982 in arterial and venous blood and genitalia following intravenous injection were measured. The results demonstrated favourable transfer of the drug into various internal genital organs. T-1982 was administered to 12 patients. The efficacy rate was 75.0%, that is to say, good in 9 cases. No side effects were noted in any cases. It is, therefore, presumed that T-1982 is a useful drug for the infectious diseases in the field of obstetrics and gynecology although the number of subjects was not so large in this study.

[Heat therapy]

Applications of hyperthermia in cancer therapy is now widely studied. Appropriate apparatus for the tumors with various size and positions should be developed. We are developing a system with 2450 MHz microwave and constructed several applicators for the surface tumors and intracavitary tumors. Those were already used in human tumors. Capacitive heating with RF were used for the combined therapy with radiation in Kyoto University. More than 50% of the treated cases were responded well resulting complete regression of tumors. Experimental system of heating with magnetic induction is now studied.

[Clinical trial of cancer therapy by radiation combined with hyperthermia]

A clinical trial of radiation therapy combined with hyperthermia for various superficial tumors was performed. For the local hyperthermia, heating modalities with microwave, radiofrequency and ultrasound can be used. Some are still insufficient for clinical application in terms of tumor size and site; there fore, for ther studies through a phase II study are necessary to determine a future direction of hyperthermia in clinical case.

Effect of irradiation and chemotherapeutic agents on the capillaries of Ehrlich ascites carcinoma of mice

The effect of irradiation and chemotherapeutic agents on the capillaries of experimental solid tumours was analysed by the resin cast method. The most evident change of the 5 vascular layers was rarefaction of the newly produced extruding capillaries on the surface of the tumour mass, which was related to the tumour growth.

Vascular structure of experimental tumours. Appearances in scanning electron microscope

The vascular structure of experimental tumours was investigated by a resin cast technique. Six characteristic types of capillaries were found: club-like, wave-like, tortuous,sinusoid-like, disorderly running and tapering. The vascular structure was correlated to the tumour growth.

Radiation effects on the fine blood vessels in abdominal organs of mice

The capillary networks of normal and irradiated abdominal organs of mouse were investigated by a resin cast technique. The structure of the capillary system had characteristic appearances. Radiation effects on the fine vascular structures were demonstrated from one appearances. Radiation effects on the fine vascular structures were demonstrated from one to 30 days after a single dose of 5 to 30 Gy whole body irradiation. Prominent morphologic abnormalities of the shape and distribution of the capillaries were identified, especially in the small intestine.