Subanesthetic Dose of Propofol Activates the Reward System in Rats.

BACKGROUND: Propofol has addictive properties, even with a single administration, and facilitates dopamine secretion in the nucleus accumbens (NAc). Activation of the dopaminergic circuits of the midbrain reward system, including the ventral tegmental area (VTA) and NAc, plays a crucial role in addiction. However, the effects of propofol on synaptic transmission and biochemical changes in the VTA-NAc circuit remain unclear. METHODS: We investigated the effects of subanesthetic doses of propofol on rat VTA neurons and excitatory synaptic transmission in the NAc using slice patch-clamp experiments. Using immunohistochemistry and western blot analyses, we evaluated the effects of intraperitoneal propofol administration on the expression of addiction-associated transcription factor ΔFosB (truncated form of the FBJ murine osteosarcoma viral oncogene homolog B protein) in the NAcs in 5-week-old rats. RESULTS: In the current-clamp mode, a subanesthetic dose (0.5-5 µmol/L) of propofol increased the action potential frequency in about half the VTA neurons (excited neurons: control: 9.4 ± 3.0 Hz, propofol 0.5 µmol/L: 21.5 ± 6.0 Hz, propofol 5 µmol/L: 14.6 ± 5.3 Hz, wash: 2.0 ± 0.7 Hz, n = 14/27 cells; unchanged/suppressed neurons: control: 1.68 ± 0.94 Hz, propofol 0.5 µmol/L: 1.0 ± 0.67 Hz, propofol 5 µmol/L: 0.89 ± 0.87 Hz, wash: 0.16 ± 0.11 Hz, n = 13/27 cells). In the voltage-clamp mode, about half the VTA principal neurons showed inward currents with 5 µmol/L of propofol (inward current neurons: control: -20.5 ± 10.0 pA, propofol 0.5 µmol/L: -62.6 ± 14.4 pA, propofol 5 µmol/L: -85.2 ± 18.3 pA, propofol 50 µmol/L: -17.1 ± 39.2 pA, washout: +30.5 ± 33.9 pA, n = 6/11 cells; outward current neurons: control: -33.9 ± 14.6 pA, propofol 0.5 µmol/L: -29.5 ± 16.0 pA, propofol 5 µmol/L: -0.5 ± 20.9 pA, propofol 50 µmol/L: +38.9 ± 18.5 pA, washout: +40.8 ± 32.1 pA, n = 5/11 cells). Moreover, 0.5 µmol/L propofol increased the amplitudes of evoked excitatory synaptic currents in the NAc, whereas >5 µmol/L propofol decreased them (control: 100.0 ± 2.0%, propofol 0.5 µmol/L: 118.4 ± 4.3%, propofol 5 µmol/L: 98.3 ± 3.3%, wash [within 10 min]: 70.7 ± 3.3%, wash [30 minutes later]: 89.9 ± 2.5%, n = 13 cells, P < .001, Dunnett's test comparing control and propofol 0.5 µmol/L). Intraperitoneally administered subanesthetic dose of propofol increased ΔFosB expression in the NAc, but not in VTA, 2 and 24 hours after administration, compared with the Intralipid control group (propofol 2 hours: 0.94 ± 0.15, 24 hours: 0.68 ± 0.07; Intralipid 2 hours: 0.40 ± 0.03, 24 hours: 0.37 ± 0.06, P = .0002 for drug in the 2-way analysis of variance). CONCLUSIONS: Even a single administration of a subanesthetic dose of propofol may cause rewarding change in the central nervous system. Thus, there is a potential propofol rewarding effect among patients receiving anesthesia or sedation with propofol, as well as among health care providers exposed to propofol.

Clinical course of 2019 novel coronavirus disease (COVID-19) in individuals present during the outbreak on the Diamond Princess cruise ship.

We investigated the clinical course of individuals with 2019 novel coronavirus disease (COVID-19) who were transferred from the Diamond Princess cruise ship to 12 local hospitals. The conditions and clinical courses of patients with pneumonia were compared with those of patients without pneumonia. Among 70 patients (median age: 67 years) analyzed, the major symptoms were fever (64.3%), cough (54.3%), and general fatigue (24.3%). Forty-three patients (61.4%) had pneumonia. Higher body temperature, heart rate, and respiratory rate as well as higher of lactate dehydrogenase (LDH), aspartate aminotransferase (AST), and C-reactive protein (CRP) levels and lower serum albumin level and lymphocyte count were associated with the presence of pneumonia. Ground-glass opacity was found in 97.7% of the patients with pneumonia. Patients were administered neuraminidase inhibitors (20%), lopinavir/ritonavir (32.9%), and ciclesonide inhalation (11.4%). Mechanical ventilation and veno-venous extracorporeal membrane oxygenation was performed on 14 (20%) and 2 (2.9%) patients, respectively; two patients died. The median duration of intubation was 12 days. The patients with COVID-19 transferred to local hospitals during the outbreak had severe conditions and needed close monitoring. The severity of COVID-19 depends on the presence of pneumonia. High serum LDH, AST and CRP levels and low serum albumin level and lymphocyte count were found to be predictors of pneumonia. It was challenging for local hospitals to admit and treat these patients during the outbreak of COVID-19. Assessment of severity was crucial to manage a large number of patients.

Is Whole-Body CT Associated With Reduced In-Hospital Mortality in Children With Trauma? A Nationwide Study.

OBJECTIVES: We aimed to investigate whether whole-body CT for children with trauma is associated with a different mortality than only selective CT. DESIGN: A multicenter, retrospective cohort study. SETTING: Nationwide trauma registry from 183 tertiary emergency medical centers in Japan. PATIENTS: We enrolled pediatric trauma patients less than 16 years old who underwent whole-body CT or selective CT from 2004 to 2014. INTERVENTIONS: We classified the patients into a whole-body CT group if they underwent head, chest, abdomen, and pelvis CT and a selective CT group if they underwent at least one, but not all, of the above scans. MEASUREMENTS AND MAIN RESULTS: We analyzed data from 9,170 eligible patients (males, 6,362 [69%]; median age, 9 yr [6-12 yr]). Of these, 3,501 (38%) underwent whole-body CT. The overall in-hospital mortality was 180 of 9,170 (2.0%), that of patients who underwent whole-body CT was 102 of 3,501 (2.9%), and that of patients who underwent selective CT was 78 of 5,669 (1.4%). After adjusted multilevel logistic regressions and propensity score matching, the whole-body CT group demonstrated no significant difference in terms of in-hospital mortality compared with the selective CT group. The adjusted odds ratios (whole-body CT vs selective CT) for in-hospital mortality were as follows: multilevel logistic regression model 1 (1.05 [95% CI, 0.70-1.56]); multilevel logistic regression model 2 (0.72 [95% CI, 0.44-1.17]); propensity score-matched model 1 (0.98 [95% CI, 0.65-1.47]); and propensity score-matched model 2 (0.71 [95% CI, 0.46-1.08]). Subgroup analyses also revealed similarities between CT selection and in-hospital mortality. CONCLUSIONS: In this nationwide study, whole-body CT was frequently used among Japanese children with trauma. However, compared with the use of selective CT, our results did not support the use of whole-body CT to reduce in-hospital mortality. Selective use of imaging may result in less radiation exposure and provide more benefits than whole-body CT to pediatric trauma patients.

Epidemiology and patterns of tracheostomy practice in patients with acute respiratory distress syndrome in ICUs across 50 countries.

BACKGROUND: To better understand the epidemiology and patterns of tracheostomy practice for patients with acute respiratory distress syndrome (ARDS), we investigated the current usage of tracheostomy in patients with ARDS recruited into the Large Observational Study to Understand the Global Impact of Severe Acute Respiratory Failure (LUNG-SAFE) study. METHODS: This is a secondary analysis of LUNG-SAFE, an international, multicenter, prospective cohort study of patients receiving invasive or noninvasive ventilation in 50 countries spanning 5 continents. The study was carried out over 4 weeks consecutively in the winter of 2014, and 459 ICUs participated. We evaluated the clinical characteristics, management and outcomes of patients that received tracheostomy, in the cohort of patients that developed ARDS on day 1-2 of acute hypoxemic respiratory failure, and in a subsequent propensity-matched cohort. RESULTS: Of the 2377 patients with ARDS that fulfilled the inclusion criteria, 309 (13.0%) underwent tracheostomy during their ICU stay. Patients from high-income European countries (n = 198/1263) more frequently underwent tracheostomy compared to patients from non-European high-income countries (n = 63/649) or patients from middle-income countries (n = 48/465). Only 86/309 (27.8%) underwent tracheostomy on or before day 7, while the median timing of tracheostomy was 14 (Q1-Q3, 7-21) days after onset of ARDS. In the subsample matched by propensity score, ICU and hospital stay were longer in patients with tracheostomy. While patients with tracheostomy had the highest survival probability, there was no difference in 60-day or 90-day mortality in either the patient subgroup that survived for at least 5 days in ICU, or in the propensity-matched subsample. CONCLUSIONS: Most patients that receive tracheostomy do so after the first week of critical illness. Tracheostomy may prolong patient survival but does not reduce 60-day or 90-day mortality. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02010073 . Registered on 12 December 2013.

Resuscitative endovascular balloon occlusion of the aorta versus aortic cross clamping among patients with critical trauma: a nationwide cohort study in Japan.

BACKGROUND: Measures of aortic occlusion (AO) for resuscitation in patients with severe torso trauma remain controversial. Our aim was to characterize the current use of resuscitative endovascular balloon occlusion of the aorta (REBOA) and resuscitative open aortic cross-clamping (ACC), and to evaluate whether REBOA should be an alternative method to resuscitative open ACC. METHODS: This study was a retrospective cohort study between 2004 and 2013 from a nationwide trauma registry in Japan. Participants were selected who underwent either REBOA or ACC. Their characteristics, interventions, and outcomes were analyzed to compare REBOA and ACC directly. The primary outcome was in-hospital mortality and the secondary outcome was mortality in the emergency department. Logistic regression analysis was performed to compare the outcomes between REBOA and ACC with adjustment for severity; 1:1 propensity score matching was also performed. RESULTS: Of the 159,157 trauma patients, 903 were eligible based on the selection criteria. Overall, 405/607 patients (67%) who had REBOA died compared to 210/233 patients (90%) who had ACC. Patients with REBOA had higher revised trauma score (RTS) (mean ± SD, 5.2 ± 2.0 vs. 4.2 ± 2.2; P < 0.001) but higher Injury Severity Score (ISS) (median (interquartile); 34 (25) vs. 34 (20); P < 0.001), and higher probability of survival (0.43 ± 0.36 vs. 0.27 ± 0.30; P < 0.001) compared to those with ACC. REBOA had an odds ratio (OR) for in-hospital mortality of 0.309 (95% confidence interval (CI) = 0.190-0.502) adjusting for trauma and injury severity score using a logistic regression model (n = 903). Similar associations were observed adjusting for RTS (OR = 0.224; 95% CI = 0.129-0.700) or adjusting for ISS (OR, 0.188; 95% CI, 0.116 to 0.303). In the propensity score-matched cohort (n = 304), REBOA was associated with lower mortality compared to ACC (OR, 0.261; 95% CI, 0.130 to 0.523). Patients with REBOA had less severe chest complications than those with ACC (Abbreviated Injury Scale thorax, 3.8 ± 0.8 vs. 4.2 ± 0.8; P < 0.001), although physiological severity and backgrounds were similar in this population. CONCLUSIONS: Patients who underwent AO had a high mortality. REBOA might be a favorable alternative method to resuscitative ACC for severe torso trauma although some indication bias could still remain. Further studies are needed to elucidate optimal indications.

External Validation for Acute Kidney Injury Severity Scores: A Multicenter Retrospective Study in 14 Japanese ICUs.

BACKGROUND/AIMS: Acute kidney injury (AKI) is associated with high mortality. Multiple AKI severity scores have been derived to predict patient outcome. We externally validated new AKI severity scores using the Japanese Society for Physicians and Trainees in Intensive Care (JSEPTIC) database. METHODS: New AKI severity scores published in the 21st century (Mehta, Stuivenberg Hospital Acute Renal Failure (SHARF) II, Program to Improve Care in Acute Renal Disease (PICARD), Vellore and Demirjian), Liano, Simplified Acute Physiology Score (SAPS) II and lactate were compared using the JSEPTIC database that collected retrospectively 343 patients with AKI who required continuous renal replacement therapy (CRRT) in 14 intensive care units. Accuracy of the severity scores was assessed by the area under the receiver-operator characteristic curve (AUROC, discrimination) and Hosmer-Lemeshow test (H-L test, calibration). RESULTS: The median age was 69 years and 65.8% were male. The median SAPS II score was 53 and the hospital mortality was 58.6%. The AUROC curves revealed low discrimination ability of the new AKI severity scores (Mehta 0.65, SHARF II 0.64, PICARD 0.64, Vellore 0.64, Demirjian 0.69), similar to Liano 0.67, SAPS II 0.67 and lactate 0.64. The H-L test also demonstrated that all assessed scores except for Liano had significantly low calibration ability. CONCLUSIONS: Using a multicenter database of AKI patients requiring CRRT, this study externally validated new AKI severity scores. While the Demirjian's score and Liano's score showed a better performance, further research will be required to confirm these findings.

The lower limit of intensity to control uremia during continuous renal replacement therapy.

INTRODUCTION: The recommended lower limit of intensity during continuous renal replacement therapy (CRRT) is 20 or 25 mL/kg/h. However, limited information is available to support this threshold. We aimed to evaluate the impact of different intensities of CRRT on the clearance of creatinine and urea in critically ill patients with severe acute kidney injury (AKI). METHODS: This is a multicenter retrospective study conducted in 14 Japanese ICUs in 12 centers. All patients older than 18 years and treated with CRRT due to AKI were eligible. We evaluated the effect of CRRT intensity by two different definitions: daily intensity (the mean intensity over each 24-h period) and average intensity (the mean of daily intensity during the period while CRRT was performed). To study the effect of different CRRT intensity on clearance of urea and creatinine, all patients/daily observations were arbitrarily allocated to one of 4 groups based on the average intensity and daily intensity: <10, 10-15, 15-20, and >20 mL/kg/h. RESULTS: Total 316 patients were included and divided into the four groups according to average CRRT intensity. The groups comprised 64 (20.3%), 138 (43.7%), 68 (21.5%), and 46 patients (14.6%), respectively. Decreases in creatinine and urea increased as the average intensity increased over the first 7 days of CRRT. The relative changes of serum creatinine and urea levels remained close to 1 over the 7 days in the "<10" group. Total 1,101 daily observations were included and divided into the four groups according to daily CRRT intensity. The groups comprised 254 (23.1%), 470 (42.7%), 239 (21.7%), and 138 observations (12.5%), respectively. Creatinine and urea increased (negative daily change) only in the "<10" group and decreased with the increasing daily intensity in the other groups. CONCLUSIONS: The lower limit of delivered intensity to control uremia during CRRT was approximately between 10 and 15 mL/kg/h in our cohort. A prescribed intensity of approximately 15 mL/kg/h might be adequate to control uremia for patients with severe AKI in the ICU. However, considering the limitations due to the retrospective nature of this study, prospective studies are required to confirm our findings.

Respiratory-like movements during an apnea test.

Background: Despite the possible occurrence of spontaneous movements during an apnea test, respiratory-like movements are rare. Case Presentation: A 51-year-old man was transferred to our hospital when a sudden disturbance of consciousness developed into cardiac arrest. After spontaneous circulation returned, we diagnosed bilateral cerebellar hemorrhage. He remained comatose with dilated pupils, absent brainstem reflexes, spontaneous breathing, and electrocerebral activity. After being considered brain dead, his family opted for organ donation. The first legal brain death examination on day 5 was aborted because of respiratory-like movements mimicking repetitive abdominal respiration during the apnea test. However, an enhanced magnetic resonance image of the head indicated no blood flow and somatosensory evoked potential testing revealed no brain-derived potentials. Conclusion: Respiratory-like movements can occur during the apnea test in patients considered brain dead. Further research is required to understand this phenomenon.

Validity of low-intensity continuous renal replacement therapy*.

OBJECTIVE: To study the hospital mortality of patients with severe acute kidney injury treated with low-intensity continuous renal replacement therapy. DESIGN: Multicenter retrospective observational study (Japanese Society for Physicians and Trainees in Intensive Care), combined with previously conducted multinational prospective observational study (Beginning and Ending Supportive Therapy). SETTING: Fourteen Japanese ICUs in 12 tertiary hospitals (Japanese Society for Physicians and Trainees in Intensive Care) and 54 ICUs in 23 countries (Beginning and Ending Supportive Therapy). PATIENTS: Consecutive adult patients with severe acute kidney injury requiring continuous renal replacement therapy admitted to the participating ICUs in 2010 (Japanese Society for Physicians and Trainees in Intensive Care, n = 343) and 2001 (Beginning and Ending Supportive Therapy Beginning and Ending Supportive Therapy, n = 1,006). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Patient characteristics, variables at continuous renal replacement therapy initiation, continuous renal replacement therapy settings, and outcomes (ICU and hospital mortality and renal replacement therapy requirement at hospital discharge) were collected. Continuous renal replacement therapy intensity was arbitrarily classified into seven subclasses: less than 10, 10-15, 15-20, 20-25, 25-30, 30-35, and more than 35 mL/kg/hr. Multivariable logistic regression analysis was conducted to investigate risk factors for hospital mortality. The continuous renal replacement therapy dose in the Japanese Society for Physicians and Trainees in Intensive Care database was less than half of the Beginning and Ending Supportive Therapy database (800 mL/hr vs 2,000 mL/hr, p < 0.001). Even after adjusting for the body weight and dilution factor, continuous renal replacement therapy intensity was statistically different (14.3 mL/kg/hr vs 20.4 mL/kg/hr, p < 0.001). Patients in the Japanese Society for Physicians and Trainees in Intensive Care database had a lower ICU mortality (46.1% vs 55.3%, p = 0.003) and hospital mortality (58.6% vs 64.2%, p = 0.070) compared with patients in the Beginning and Ending Supportive Therapy database. In multivariable regression analysis after combining the two databases, no continuous renal replacement therapy intensity subclasses were found to be statistically different from the reference intensity (20-25 mL/kg/hr). Several sensitivity analyses (patients with sepsis, patients from Western countries in the Beginning and Ending Supportive Therapy database) confirmed no intensity-outcome relationship. CONCLUSIONS: Continuous renal replacement therapy at a mean intensity of 14.3 mL/kg/hr did not have worse outcome compared with 20-25 mL/kg/hr of continuous renal replacement therapy, currently considered the standard intensity. However, our study is insufficient to support the use of low-intensity continuous renal replacement therapy, and more studies are needed to confirm our findings.

[Labor environment and heatstroke].

The Ministry of Health, Labour and Welfare and the Heatstroke STUDY 2008 & 2010 regarding the characteristics of laborers who suffered and died from heatstroke demonstrated the involvement of more laborers who worked in construction, from July to August and at around 3 p.m. Also, more laborers who worked at around 11 a.m. got heatstroke, and there were more laborers who died from it within 1 week from starting to work. The results showed that the heat environment and the time and period when laborers started to be exposed to a hot environment adversely effect the development of heatstroke and subsequent heatstroke-related death. It is important to estimate and take measures against a hot environment and to make time to be acclimated to a hot environment.

Intensive care unit model and in-hospital mortality among patients with severe sepsis and septic shock: A secondary analysis of a multicenter prospective observational study.

ABSTRACT: We aimed to determine the association between the intensive care unit (ICU) model and in-hospital mortality of patients with severe sepsis and septic shock.This was a secondary analysis of a multicenter prospective observational study conducted in 59 ICUs in Japan from January 2016 to March 2017. We included adult patients (aged ≥16 years) with severe sepsis and septic shock based on the sepsis-2 criteria who were admitted to an ICU with a 1:2 nurse-to-patient ratio per shift. Patients were categorized into open or closed ICU groups, according to the ICU model. The primary outcome was in-hospital mortality.A total of 1018 patients from 45 ICUs were included in this study. Patients in the closed ICU group had a higher severity score and higher organ failure incidence than those in the open ICU group. The compliance rate for the sepsis care 3-h bundle was higher in the closed ICU group than in the open ICU group. In-hospital mortality was not significantly different between the closed and open ICU groups in a multilevel logistic regression analysis (odds ratio = 0.83, 95% confidence interval; 0.52-1.32, P = .43) and propensity score matching analysis (closed ICU, 21.2%; open ICU, 25.7%, P = .22).In-hospital mortality between the closed and open ICU groups was not significantly different after adjusting for ICU structure and compliance with the sepsis care bundle.

Clinical features and outcomes of prolonged mechanical ventilation: a single-center retrospective observational study.

BACKGROUND: Information on epidemiology of prolonged mechanical ventilation (PMV) patients in the acute care setting in Japan is totally lacking. We aimed to investigate clinical features, impact, and long-term outcomes of PMV patients. METHODS: This was a retrospective observational study conducted in a tertiary care hospital. Adult patients who were admitted to our intensive care unit (ICU) from April 2009 to March 2014 and required mechanical ventilation (MV) for ≥ 2 days were included. PMV was defined as having MV for ≥ 21 consecutive days. RESULTS: Among 1282 MV patients, 93 (7.3%) required PMV, and median duration of MV was 37.0 days. Compared with the non-PMV patients, PMV patients had longer total ICU and high care unit (HCU) stay (34.0 vs. 7.0 days, p < 0.001), longer hospital stay (74.0 vs. 35.0 days, p < 0.001), and higher hospital mortality (54.8 vs. 21.4%, p < 0.001). In multivariable logistic regression analysis, emergency ICU admission and steroid use during MV were associated with PMV. The Kaplan-Meier curves for MV withdrawal and ICU/HCU discharge were almost identical. Among PMV patients, 52 (55.9%) died, 29 (31.2%) were successfully liberated from MV during hospitalization, and 12 (12.9%) still required MV at discharge. CONCLUSION: In this investigation, 7.3% of the patients with MV required PMV. Most PMV patients were liberated from MV during hospitalization, while occupying critical care beds for an extended period. A nationwide survey is required to further elucidate the overall picture of PMV patients and to discuss whether specialized weaning centers to treat PMV patients are required in Japan.

Variations in infection sites and mortality rates among patients in intensive care units with severe sepsis and septic shock in Japan.

BACKGROUND: Accurate and early identification of infection sites might help to drive crucial decisions regarding the treatment of sepsis. We aimed to determine the clinical and etiological features of infection according to sites among patients with severe sepsis in Japan. METHODS: This secondary analysis of a multicenter, prospective cohort study included 59 intensive care units (ICU) and proceeded between January 2016 and March 2017. The study cohort comprised 1184 adults (≥ 16 years) who were admitted to an ICU with severe sepsis and septic shock diagnosed according to the sepsis-2 criteria. Sites of infection diagnosed by physicians in charge at the time of arrival comprised the lung, abdomen, urinary tract, soft tissue, bloodstream, central nervous system (CNS), and undifferentiated infections. The primary outcome was in-hospital mortality. RESULTS: The most common sites of infection were the lungs (31.0%), followed by intra-abdominal sites (26.3%), the urinary tract (18.4%), and soft tissue (10.9%). The characteristics of the patients with severe sepsis across seven major suspected infection sites were heterogeneous. Septic shock was more frequent among patients with intra-abdominal (72.2%) and urinary tract (70.2%) infections than other sites. The in-hospital mortality rate due to severe sepsis and septic shock of a pooled sample was 23.4% (range, 11.9% [urinary tract infection] to 47.6% [CNS infection]). After adjusting for clinical background, sepsis severity, and stratification according to the presence or absence of shock, variations in hospital mortality across seven major sites of infection remained essentially unchanged from those for crude in-hospital mortality; adjusted in-hospital mortality rates ranged from 7.7% (95%CI, - 0.3 to 15.8) for urinary tract infection without shock to 58.3% (95%CI, 21.0-95.7) for CNS infection with shock in a generalized estimating equation model. Intra-abdominal and urinary tract infections were statistically associated with less in-hospital mortality than pneumonia. Infections of the CNS were statistically associated with higher in-hospital mortality rates than pneumonia in a logistic regression model, but not in the generalized estimating equation model. CONCLUSIONS: In-hospital mortality and clinical features of patients with severe sepsis and septic shock were heterogeneous according to sites of infection.

Regeneration of nigrostriatal dopaminergic axons after transplantation of olfactory ensheathing cells and fibroblasts prevents fibrotic scar formation at the lesion site.

The fibrotic scar formed after central nervous system injury has been considered an obstacle to axonal regeneration. The present study was designed to examine whether cell transplantation into a damaged central nervous system can reduce fibrotic scar formation and promote axonal regeneration. Nigrostriatal dopaminergic axons were unilaterally transected in rats and cultures of olfactory-ensheathing cells (OECs), and olfactory nerve fibroblasts were transplanted into the lesion site. In the absence of transplants, few tyrosine hydroxylase-immunoreactive axons extended across the lesion 2 weeks after the transection. Reactive astrocytes increased around the lesion, and a fibrotic scar containing type IV collagen deposits developed in the lesion center. The immunoreactivity of chondroitin sulfate side chains and core protein of NG2 proteoglycan increased in and around the lesion. One and 2 weeks after transection and simultaneous transplantation, dopaminergic axons regenerated across the transplanted tissues, which consisted of p75-immunoreactive OECs and fibronectin-immunoreactive fibroblasts. Reactive astrocytes and chondroitin sulfate immunoreactivity increased around the transplants, whereas the deposition of type IV collagen and fibrotic scar formation were completely prevented at the lesion site. Transplantation of meningeal fibroblasts similarly prevented the formation of the fibrotic scar, although its effect on regeneration was less potent than transplantation of OECs and olfactory nerve fibroblasts. The present results suggest that elimination of the inhibitory fibrotic scar is important for neural regeneration.

Differential effects of isoflurane on A-type and delayed rectifier K channels in rat substantia nigra.

The authors previously demonstrated that isoflurane, a widely used volatile anesthetic, induced depolarization and increased the frequency of spontaneous action potentials in principal dopamine neurons in rat substantia nigra pars compacta. We studied the effects of isoflurane on voltage-dependent K channels to clarify the mechanisms of the increase in excitability in these neurons. Voltage-clamp whole-cell recordings were made in rat midbrain slices. We recorded the outward membrane currents in response to depolarizing voltage steps from -120 mV and -25 mV and isolated the transient outward current mediated through A-type K channels by subtraction. Isoflurane at clinically relevant concentrations accelerated the decay of the A-type K current and delayed the recovery from inactivation without changing the steady-state inactivation curves. Isoflurane did not affect the non-inactivating outward current. Addition of 4-aminopyridine partially occluded the excitatory effects of isoflurane in current-clamp recordings. These results demonstrate that isoflurane accelerated the inactivation and delayed the recovery from inactivation of A-type K channels in principal neurons in rat substantia nigra pars compacta without affecting delayed rectifier K channels. These effects may contribute in part to excitation of these neurons and the isoflurane-induced increases in dopamine release reported in vitro and in vivo.

Ten-year inhospital mortality trends for patients with trauma in Japan: a multicentre observational study.

OBJECTIVES: Trauma is one of the main causes of death in Japan, and treatments and prognoses of these injuries are constantly changing. We therefore aimed to investigate a 10-year trend (2004-2013) in inhospital mortality among patients with trauma in Japan. DESIGN: Multicentre observational study. SETTING: Japanese nationwide trauma registry (the Japan Trauma Data Bank) data. PARTICIPANTS: All patients with trauma whose Injury Severity Score (ISS) were 3 and above, who were aged 15 years or older, and whose mechanisms of injury (MOI) were blunt and penetrating between 2004 and 2013 (n=90 833). OUTCOME MEASURES: A 10-year trend in inhospital mortality. RESULTS: Inhospital mortality for all patients with trauma significantly decreased over the study decade in our Cochran-Armitage test (P<0.001). Similarly, inhospital mortality for patients with ISS 16 or more and patients who scored 50% or better on the Trauma and Injury Severity Score (TRISS) probability of survival scale significantly decreased (P<0.001). In addition, the OR for inhospital mortality of these three patient groups decreased yearly after adjusting for age, gender, MOI, ISS, Glasgow Coma Scale, systolic blood pressure and respiratory rate on hospital arrival in multivariable logistic regression analyses. Furthermore, inhospital mortality for patient with blunt trauma significantly decreased in injury mechanism-stratified Mantel-extension testing (P<0.001). Finally, multivariable logistic regression analyses showed that the OR for inhospital mortality of patients with ISS 16 and over decreased each year after adding and adjusting for means of transportation and usage of whole-body CT. CONCLUSION: Inhospital mortality for patients with trauma in Japan significantly decreased during the study decade after adjusting for patient characteristics, injury severity and the response environment after injury.

Disrupting effects of hydroxy-polychlorinated biphenyl (PCB) congeners on neuronal development of cerebellar Purkinje cells: a possible causal factor for developmental brain disorders?

Polychlorinated biphenyls (PCBs) and hydroxy-PCB (OH-PCB) metabolites are widely distributed bioaccumulative environmental chemicals and have similar chemical structures to those of thyroid hormones (THs). Previously, we reported that THs are essential for neuronal development and the low doses of two OH-PCBs, namely, 4-OH-2',3,3',4',5'-pentachlorobiphenyl (4'-OH-PeCB-106) and 4-OH-2',3,3',4',5,5'-hexachlorobiphenyl (4'-OH-HxCB-159), inhibited the TH-dependent dendritic development of Purkinje cells in mouse cerebellar cultures using serum-free defined medium. To determine which type of OH-PCBs affect neuronal development, we further examined several OH-PCBs and other estrogenic chemicals using this simple and sensitive assay system. Two-way ANOVA was used to assess the effects of OH-PCBs and other chemicals on both factors of their concentrations and with/without T4 in the assay of TH-dependent dendritic development of Purkinje cells. Aside from the two OH-PCBs, 4-OH-2',3,4',5,6'-pentachlorobiphenyl (4'-OH-PeCB-121) and bisphenol A significantly inhibited the TH-dependent dendritic development of Purkinje cells, whereas 4-OH-2',3,3',5',6'-pentachlorobiphenyl (4'-OH-PeCB-112), 4-OH-2',3,3',5,5',6'-hexachlorobiphenyl (4'-OH-HxCB-165), 4-OH-2,2',3,4',5,5',6-heptachlorobiphenyl (4-OH-HpCB-187), progesterone and nonylphenol did not induce any inhibition, but significantly promoted the dendritic extension of Purkinje cells in the absence of THs. Other estrogenic chemicals, including beta-estradiol, diethyl stilbestrol and p-octylphenol did not show significant inhibitory or promoting effects. From these results, it is suggested that exposure to OH-PCBs and other environmental chemicals may disrupt normal neuronal development and cause some developmental brain disorders, such as LD, ADHD, and autism.

Aligned neurite bundles of granule cells regulate orientation of Purkinje cell dendrites by perpendicular contact guidance in two-dimensional and three-dimensional mouse cerebellar cultures.

To identify structures that determine the 90 degree orientation of thin espalier dendritic trees of Purkinje cells with respect to parallel fibers (axonal neurite bundles of granule cells) in the cerebellar cortex, we designed five types of two-dimensional and three-dimensional cell and tissue cultures of cerebella from postnatal mice and analyzed the orientation of Purkinje cell dendrites with respect to neurite bundles and astrocyte fibers by immunofluorescence double or triple staining. We cultured dissociated cerebellar cells on micropatterned substrates and preformed neurite bundles of a microexplant culture two-dimensionally and in matrix gels three-dimensionally. Dendrites, but not axons, of Purkinje cells extended toward the neurites of granule cells and oriented at right angles two-dimensionally to aligned neurite bundles in the three cultures. In a more organized explant proper of the microexplant culture, Purkinje cell dendrites extended toward thin aligned neurite bundles not only consistently at right angles but also two-dimensionally. However, in the "organotypic microexplant culture," in which three-dimensionally aligned thick neurite bundles mimicking parallel fibers were produced, Purkinje cell dendrites often oriented perpendicular to the thick bundles three-dimensionally. Astrocytes were abundant in all cultures, and there was no definite correlation between the presence of and orientation to Purkinje cell dendrites, although their fibers were frequently associated in parallel with dendrites in the organotypic microexplant culture. Therefore, Purkinje cells may grow their dendrites to the newly produced neurite bundles of parallel fibers in the cerebellar cortex and be oriented at right angles three-dimensionally mainly via "perpendicular contact guidance."

Factors related to prolonged on-scene time during ambulance transportation for critical emergency patients in a big city in Japan: a population-based observational study.

OBJECTIVES: We aimed to investigate the factors related to prolonged on-scene times, which were defined as being over 30 min, during ambulance transportation for critical emergency patients in the context of a large Japanese city. DESIGN: A population-based observational study. SETTING: Kawasaki City, Japan's eighth largest city. PARTICIPANTS: The participants in this study were all critical patients (age ≥ 15 years) who were transported by ambulance between April 2010 and March 2013 (N=11,585). OUTCOME MEASURES: On-scene time during ambulance transportation for critical emergency patients. RESULTS: The median on-scene time for all patients was 17 min (IQR 13-23). There was a strong correlation between on-scene time and the number of phone calls to hospitals from emergency medical service (EMS) personnel (p<0.001). In multivariable logistic regression, the number of phone calls to hospitals from EMS personnel, intoxication, minor disease and geographical area were associated with on-scene times over 30 min. Age, gender, day of the week and time of the day were not associated with on-scene times over 30 min. CONCLUSIONS: To make on-scene time shorter, it is vital to redesign our emergency system and important to develop a system that accommodates critical patients with intoxication and minor disease, and furthermore to reduce the number of phone calls to hospitals from EMS personnel.