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.

Weaning from mechanical ventilation in intensive care units across 50 countries (WEAN SAFE): a multicentre, prospective, observational cohort study

BACKGROUND

Current management practices and outcomes in weaning from invasive mechanical ventilation are poorly understood. We aimed to describe the epidemiology, management, timings, risk for failure, and outcomes of weaning in patients requiring at least 2 days of invasive mechanical ventilation.

METHODS

WEAN SAFE was an international, multicentre, prospective, observational cohort study done in 481 intensive care units in 50 countries. Eligible participants were older than 16 years, admitted to a participating intensive care unit, and receiving mechanical ventilation for 2 calendar days or longer. We defined weaning initiation as the first attempt to separate a patient from the ventilator, successful weaning as no reintubation or death within 7 days of extubation, and weaning eligibility criteria based on positive end-expiratory pressure, fractional concentration of oxygen in inspired air, and vasopressors. The primary outcome was the proportion of patients successfully weaned at 90 days. Key secondary outcomes included weaning duration, timing of weaning events, factors associated with weaning delay and weaning failure, and hospital outcomes. This study is registered with ClinicalTrials.gov, NCT03255109.

FINDINGS

Between Oct 4, 2017, and June 25, 2018, 10 232 patients were screened for eligibility, of whom 5869 were enrolled. 4523 (77·1%) patients underwent at least one separation attempt and 3817 (65·0%) patients were successfully weaned from ventilation at day 90. 237 (4·0%) patients were transferred before any separation attempt, 153 (2·6%) were transferred after at least one separation attempt and not successfully weaned, and 1662 (28·3%) died while invasively ventilated. The median time from fulfilling weaning eligibility criteria to first separation attempt was 1 day (IQR 0-4), and 1013 (22·4%) patients had a delay in initiating first separation of 5 or more days. Of the 4523 (77·1%) patients with separation attempts, 2927 (64·7%) had a short wean (≤1 day), 457 (10·1%) had intermediate weaning (2-6 days), 433 (9·6%) required prolonged weaning (≥7 days), and 706 (15·6%) had weaning failure. Higher sedation scores were independently associated with delayed initiation of weaning. Delayed initiation of weaning and higher sedation scores were independently associated with weaning failure. 1742 (31·8%) of 5479 patients died in the intensive care unit and 2095 (38·3%) of 5465 patients died in hospital.

INTERPRETATION

In critically ill patients receiving at least 2 days of invasive mechanical ventilation, only 65% were weaned at 90 days. A better understanding of factors that delay the weaning process, such as delays in weaning initiation or excessive sedation levels, might improve weaning success rates.

FUNDING

European Society of Intensive Care Medicine, European Respiratory Society.

ADC Level is Related to DWI Reversal in Patients Undergoing Mechanical Thrombectomy: A Retrospective Cohort Study

BACKGROUND AND PURPOSE

In patients with ischemic stroke, DWI lesions can occasionally be reversed by reperfusion therapy. This study aimed to ascertain the relationship between ADC levels and DWI reversal in patients with acute ischemic stroke who underwent recanalization treatment.

MATERIALS AND METHODS

We conducted a retrospective cohort study in patients with acute ischemic stroke who underwent endovascular mechanical thrombectomy with successful recanalization between April 2017 and March 2021. DWI reversal was assessed through follow-up MR imaging approximately 24 hours after treatment.

RESULTS

In total, 118 patients were included. DWI reversal was confirmed in 42 patients. The ADC level in patients with reversal was significantly higher than that in patients without reversal. Eighty-three percent of patients with DWI reversal areas had mean ADC levels of ≥520 × 10^-6 mm²/s, and 71% of patients without DWI reversal areas had mean ADC levels of <520 × 10^-6 mm²/s. The mean ADC threshold was 520 × 10^-6 mm²/s with a sensitivity and specificity of 71% and 83%, respectively. In multivariate analysis, the mean ADC level (OR, 1.023; 95% CI, 1.013-1.033; P < .0001) was independently associated with DWI reversal. Patients with DWI reversal areas had earlier neurologic improvement (NIHSS at 7 days) than patients without reversal areas (P < .0001).

CONCLUSIONS

In acute ischemic stroke, the ADC value is independently associated with DWI reversal. Lesions with a mean ADC of ≥520 × 10^-6 mm²/s are salvageable by mechanical thrombectomy, and DWI reversal areas regain neurologic function. The ADC value is easily assessed and is a useful tool to predict viable lesions.

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.

The Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock 2020 (J-SSCG 2020)

The Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock 2020 (J-SSCG 2020), a Japanese-specific set of clinical practice guidelines for sepsis and septic shock created as revised from J-SSCG 2016 jointly by the Japanese Society of Intensive Care Medicine and the Japanese Association for Acute Medicine, was first released in September 2020 and published in February 2021. An English-language version of these guidelines was created based on the contents of the original Japanese-language version. The purpose of this guideline is to assist medical staff in making appropriate decisions to improve the prognosis of patients undergoing treatment for sepsis and septic shock. We aimed to provide high-quality guidelines that are easy to use and understand for specialists, general clinicians, and multidisciplinary medical professionals. J-SSCG 2016 took up new subjects that were not present in SSCG 2016 (e.g., ICU-acquired weakness [ICU-AW], post-intensive care syndrome [PICS], and body temperature management). The J-SSCG 2020 covered a total of 22 areas with four additional new areas (patient- and family-centered care, sepsis treatment system, neuro-intensive treatment, and stress ulcers). A total of 118 important clinical issues (clinical questions, CQs) were extracted regardless of the presence or absence of evidence. These CQs also include those that have been given particular focus within Japan. This is a large-scale guideline covering multiple fields; thus, in addition to the 25 committee members, we had the participation and support of a total of 226 members who are professionals (physicians, nurses, physiotherapists, clinical engineers, and pharmacists) and medical workers with a history of sepsis or critical illness. The GRADE method was adopted for making recommendations, and the modified Delphi method was used to determine recommendations by voting from all committee members.As a result, 79 GRADE-based recommendations, 5 Good Practice Statements (GPS), 18 expert consensuses, 27 answers to background questions (BQs), and summaries of definitions and diagnosis of sepsis were created as responses to 118 CQs. We also incorporated visual information for each CQ according to the time course of treatment, and we will also distribute this as an app. The J-SSCG 2020 is expected to be widely used as a useful bedside guideline in the field of sepsis treatment both in Japan and overseas involving multiple disciplines.

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

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.

The Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock 2020 (J-SSCG 2020)

The Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock 2020 (J-SSCG 2020), a Japanese-specific set of clinical practice guidelines for sepsis and septic shock created as revised from J-SSCG 2016 jointly by the Japanese Society of Intensive Care Medicine and the Japanese Association for Acute Medicine, was first released in September 2020 and published in February 2021. An English-language version of these guidelines was created based on the contents of the original Japanese-language version. The purpose of this guideline is to assist medical staff in making appropriate decisions to improve the prognosis of patients undergoing treatment for sepsis and septic shock. We aimed to provide high-quality guidelines that are easy to use and understand for specialists, general clinicians, and multidisciplinary medical professionals. J-SSCG 2016 took up new subjects that were not present in SSCG 2016 (e.g., ICU-acquired weakness [ICU-AW], post-intensive care syndrome [PICS], and body temperature management). The J-SSCG 2020 covered a total of 22 areas with four additional new areas (patient- and family-centered care, sepsis treatment system, neuro-intensive treatment, and stress ulcers). A total of 118 important clinical issues (clinical questions, CQs) were extracted regardless of the presence or absence of evidence. These CQs also include those that have been given particular focus within Japan. This is a large-scale guideline covering multiple fields; thus, in addition to the 25 committee members, we had the participation and support of a total of 226 members who are professionals (physicians, nurses, physiotherapists, clinical engineers, and pharmacists) and medical workers with a history of sepsis or critical illness. The GRADE method was adopted for making recommendations, and the modified Delphi method was used to determine recommendations by voting from all committee members. As a result, 79 GRADE-based recommendations, 5 Good Practice Statements (GPS), 18 expert consensuses, 27 answers to background questions (BQs), and summaries of definitions and diagnosis of sepsis were created as responses to 118 CQs. We also incorporated visual information for each CQ according to the time course of treatment, and we will also distribute this as an app. The J-SSCG 2020 is expected to be widely used as a useful bedside guideline in the field of sepsis treatment both in Japan and overseas involving multiple disciplines.

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.

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.

Electronic supplementary material

The online version of this article (10.1186/s40560-019-0383-3) contains supplementary material, which is available to authorized users.

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.

Electronic supplementary material

The online version of this article (10.1186/s13054-018-2126-6) contains supplementary material, which is available to authorized users.

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.

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.

Factors Predicting Successful Discontinuation of Continuous Renal Replacement Therapy

This multicentre, retrospective observational study was conducted from January 2010 to December 2010 to determine the optimal time for discontinuing continuous renal replacement therapy (CRRT) by evaluating factors predictive of successful discontinuation in patients with acute kidney injury. Analysis was performed for patients after CRRT was discontinued because of renal function recovery. Patients were divided into two groups according to the success or failure of CRRT discontinuation. In multivariate logistic regression analysis, urine output at discontinuation, creatinine level and CRRT duration were found to be significant variables (area under the receiver operating characteristic curve for urine output, 0.814). In conclusion, we found that higher urine output, lower creatinine and shorter CRRT duration were significant factors to predict successful discontinuation of CRRT.

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.

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.

The maze-making and solving technique for coil embolization of large and giant aneurysms

BACKGROUND AND PURPOSE

Despite major progress in treating aneurysms by coil embolization, the complete occlusion of aneurysms of >10 mm in diameter (large/giant aneurysms) remains challenging. We present a novel endovascular treatment method for large and giant cerebral aneurysms called the "maze-making and solving" technique and compare the short-term follow-up results of this technique with those of conventional coil embolization.

MATERIALS AND METHODS

Eight patients (65 ± 11.5 years of age, 7 women) with large/giant unruptured nonthrombosed cerebral aneurysm (mean largest aneurysm dimension, 19 ± 4.4 mm) were treated by the maze-making and solving technique, a combination of the double-catheter technique and various assisted techniques. The coil-packing attenuation, postoperative courses, and recurrence rate of this maze group were compared with 30 previous cases (conventional group, 65.4 ± 13.0 years of age; 22 women; mean largest aneurysm dimension, 13.4 ± 3.8 mm).

RESULTS

Four maze group cases were Raymond class 1; and 4 were class 2 as indicated by immediate postsurgical angiography. No perioperative deaths or major strokes occurred. Mean packing attenuation of the maze group was significantly higher than that of the conventional group (37.4 ± 5.9% versus 26.2 ± 5.6%). Follow-up angiography performed at 11.3 ± 5.4 months revealed no recurrence in the maze group compared with 39.2% in the conventional group.

CONCLUSIONS

The maze-making and solving technique achieves high coil-packing attenuation for efficient embolization of large and giant cerebral aneurysms with a low risk of recurrence.

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.

Endovascular treatment of intractable bleeding from a traumatic pseudoaneurysm of the internal maxillary artery

Traumatic pseudoaneurysms of the internal maxillary artery (IMA) are rare and difficult to treat. A 58-year-old man with a traumatic pseudoaneurysm of the IMA presented with intractable nasal and oral hemorrhage during dual antiplatelet therapy. Transcatheter artery embolization with N-butyl cyanoacrylate (NBCA) completely occluded the pseudoaneurysm. Transcatheter artery embolization with NBCA is a feasible and effective treatment because of its shorter treatment time and lower incidence of recurrence.

Who may not benefit from continuous renal replacement therapy in acute kidney injury?

This study aimed to identify factors that may predict early kidney recovery (less than 48 hours) or early death (within 48 hours) after initiating continuous renal replacement therapy (CRRT) in acute kidney injury (AKI) patients. This is a multicenter retrospective observational study of 14 Japanese Intensive care units (ICUs) in 12 tertiary hospitals. Consecutive adult patients with severe AKI requiring CRRT admitted to the participating ICUs in 2010 (n=343) were included. Patient characteristics, variables at CRRT initiation, settings, and outcomes were collected. Patients were grouped into early kidney recovery group (CRRT discontinuation within 48 hours after initiation, n=52), early death group (death within 48 hours after CRRT initiation, n=52), and the rest as the control group (n=239). The mean duration of CRRT in the early kidney recovery group and early death group was 1.3 and 0.9 days, respectively. In multivariable regression analysis, in comparison with the control group, urine output (mL/h) (odds ratio [OR]: 1.02, 95% confidence interval [CI]: 1.01-1.03), duration between ICU admission to CRRT initiation (days) (OR: 0.65, 95% CI: 0.43-0.87), and the sepsis-related organ failure assessment score (OR: 0.87, 95% CI; 0.78-0.96) were related to early kidney recovery. Serum lactate (mmol/L) (OR: 1.19, 95% CI: 1.11-1.28), albumin (g/dL) (OR: 0.52, 95% CI: 0.28-0.92), vasopressor use (OR: 3.68, 95% CI: 1.37-12.16), and neurological disease (OR: 9.64, 96% CI: 1.22-92.95) were related to early death. Identifying AKI patients who do not benefit from CRRT and differentiating such patients from the study cohort may allow previous and future studies to effectively evaluate the indication and role of CRRT.

[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.

"Brush Sign" on susceptibility-weighted MR imaging indicates the severity of moyamoya disease

BACKGROUND AND PURPOSE

SWI is a high spatial resolution MR imaging technique showing magnetic inhomogeneity that could demonstrate increased oxygen extraction in focal cerebral ischemia. The aim of this study was to investigate the characteristics in the signal intensity of DMVs by using SWI and to determine whether this method could indicate the severity of the hemodynamics in MMD by evaluating the correlation between SWI stage and hemodynamics on SPECT.

MATERIALS AND METHODS

Consecutive MMD patients were prospectively analyzed before treatment. Routine MR imaging including SWI was performed, and the number of the conspicuous DMVs draining into the subependymal veins was classified: stage 1, mild (< 5); stage 2, moderate (5-10); and stage 3, severe (> 10). The SWI stage was evaluated in correlation with clinical presentations, and CBF and CVR were quantified by using a SPECT iodine 123 N-isopropyl-p-iodoamphetamine split-dose method.

RESULTS

Patients were 12 males and 21 females (range, 8-66 years), consisting of 4 asymptomatic patients, 13 patients with TIA, 9 patients with infarct, and 7 patients with hemorrhage. There was a significant difference in CVR among clinical presentations, though there was no difference in age, Suzuki stage, or CBF. Conversely, SWI stage was significantly higher in patients with TIA and infarct than asymptomatic patients (P < .01). Higher SWI stage significantly had lower CBF and CVR in the middle cerebral artery area (P < .05).

CONCLUSIONS

SWI stage strongly correlates with ischemic presentations in MMD and also correlates with hemodynamics on SPECT, especially CVR. Increased conspicuity of DMVs, known as "brush sign", could predict the severity of MMD.

Efficacy of DynaCT digital angiography in the detection of the fistulous point of dural arteriovenous fistulas

BACKGROUND AND PURPOSE

Identifying the precise hemodynamic features, including the fistulous point, is essential for treatments of dural arteriovenous fistulas (DAVFs). This study illustrates the efficacy of DynaCT digital angiograms obtained from a 3D C-arm CT to directly visualize the location of the fistulous points in DAVFs.

MATERIALS AND METHODS

This retrospective study observed 14 consecutive patients with DAVFs, which included 7 cavernous sinuses, 4 transverse-sigmoid sinuses, 2 convexity-superior sagittal sinuses, and 1 tentorial sinus. In the assessment of the practical applicability for the diagnosis of DAVFs, images obtained from 2D digital subtraction angiography (DSA) and DynaCT were comparatively evaluated.

RESULTS

In all patients, DynaCT digital angiography could clearly demonstrate the feeding arteries, the fistulous points, and the draining veins. Significant anatomic landmarks for the fistulous points with relationships to osseous structures were also provided. Compared with 2D DSA, DynaCT digital angiograms demonstrated 12 additional findings in 8 patients (57%), including the detection of the fistulous points (n = 7), the feeders (n = 1), the retrograde leptomeningeal drainage (n = 1), the draining veins (n = 1), and the venous anomaly (n = 2).

CONCLUSIONS

In comparison with 2D DSA, DynaCT may provide more detailed information to evaluate DAVFs. DynaCT digital angiograms have a high contrast and isotropic spatial resolution, allowing a reliable visualization of small vessels and fine osseous structures. Such detailed information, especially for the location of the fistulous points, could be very useful for either the endovascular or the surgical treatments of DAVFs.

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.

Difference in vulnerability of cerebral arterial bifurcation and straight portion for development of endothelial damage

Cerebral atherosclerotic changes develop most commonly on the lateral side of the bifurcation, one of the sites where the wall shear stress is lowest in the cerebral arteries. Endothelial cells exposed to the lower shear stress appear to be more vulnerable to stimuli such as free radicals. We hypothesized that the difference in endothelial vulnerability on cerebral arteries may be involved in the local preference of atherogenesis. To clarify this hypothesis, the present study was carried out by using a laser-dye technique that causes cell damage by heat and free radicals. A helium-neon laser in the presence of circulating Evans blue was used to illuminate three sites of the rat middle cerebral artery; the straight portion, the apex of the bifurcation, and the lateral side of the bifurcation. The magnitude of endothelial damage was morphologically estimated with the electron microscope. After the laser irradiation, the straight portion and the lateral side of the bifurcation developed severe endothelial damage. However, the apex of the bifurcation developed no appreciable damage, showing significantly milder changes compared with other sites. The results suggest that endothelial cells are more vulnerable to stimuli by free radicals at the straight portion and the lateral side of the bifurcation than at the apex. We conclude that the imbalance between the strength of stress stimuli, such as free radicals, and the vulnerability of endothelium is likely to be one of the key requirements for the development of cerebral atherosclerotic changes.

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.

Selective transvenous coil embolization of dural arteriovenous fistula. A report of three cases

SUMMARY

We herein report three cases of dural arteriovenous fistula (DAVF) in which the venous outlet immediately adjacent to the fistula was selectively embolized. Case 1: A 69-year-old man presented with a subarachnoid hemorrhage (SAH). Angiography demonstrated a DAVF in the left superior petrous sinus. Case 2: A 59-yearold woman presented with dizziness. Angiography demonstrated a DAVF adjacent to great vein of Galen. The DAVF drained through the great vein of Galen with retrograde leptomeningeal venous drainage (RLVD). The basal vein of Rosenthal was enhanced from the great vein of Galen. Case 3: A 51-year-old man presented with an occipital seizure. Angiography demonstrated a DAVF adjacent to the left side of the superior sagittal sinus with RLVD. All three cases were successfully treated by the selective embolization of the venous outlet immediately adjacent to the fistula. Therefore, selective embolization preserved normal venous return.

Role of diffusion-weighted magnetic resonance imaging in diffuse axonal injury

PURPOSE

To determine whether the signal changes on magnetic resonance imaging (MRI), including fluid attenuated inversion recovery (FLAIR), T2*-weighted gradient echo (GE) imaging, and diffusion-weighted imaging (DWI) in diffuse axonal injury (DAI) patients correlate with the clinical outcome.

MATERIAL AND METHODS

We diagnosed patients with DAI based on the following criteria: 1) a loss of consciousness from the time of injury that persisted beyond 6 h; 2) no apparent hemorrhagic contusion on computed tomography (CT); 3) the presence of white matter injury on MRI. Twenty-one DAI patients were analyzed (19 M, 2 F, mean age 34 years) with MRI (FLAIR, T2*-weighted GE imaging, and DWI).

RESULTS

325 abnormalities were detected by MRI within a week after injury. The T2*-weighted GE imaging was significantly more sensitive than FLAIR and DWI in diagnosing DAI. DWI detected only 32% of all lesions, but could depict additional shearing injuries not visible on either T2*-weighted GE imaging or FLAIR. The mean number of lesions in brainstem detected by DWI in the favorable group (good recovery/moderately disabled) was significantly smaller than in the unfavorable group (severely disabled/vegetative survival/death). This trend was not observed on the T2*-weighted GE imaging and FLAIR findings.

CONCLUSION

DWI cannot detect all DAI-related lesions, but is a potentially useful imaging modality for both diagnosing and assessing patients with DAI.

Dysphagia-gastroesophageal reflux complex: complications due to dysfunction of solitary tract nucleus-mediated vago-vagal reflex

We report on the complication of gastroesophageal reflux (GER) in four patients with lower brainstem dysfunction. These patients suffered from perinatal asphyxia, cerebellar hemorrhage, or congenital dysphagia of unknown origin and showed facial nerve palsy, inspiratory stridor due to vocal cord paralysis, central sleep apnea, and dysphagia, in various combinations. Naso-intestinal tube feeding was introduced in all of the patients due to recurrent vomiting and aspiration pneumonia resulting from GER. T2-weighted magnetic resonance (MR) imaging revealed symmetrical high intensity lesions in the tegmentum of the lower pons and the medulla oblongata in two of the patients, and pontomedullary atrophy in another patient. In normal subjects, lower esophageal sphincter contraction is provoked by distension of the gastric wall, through a vago-vagal reflex. Since this reflex arc involves the solitary tract nucleus, where the swallowing center is located, the association of dysphagia and GER in the present patients is thought to result from the lesions in the tegmentum of medulla oblongata. We propose the term "dysphagia-GER complex" to describe the disturbed motility of the upper digestive tract due to lower brainstem involvement. In children with brainstem lesions, neurological assessment of GER is warranted, in addition to the examination of other signs of brainstem dysfunction, including dysphagia and respiratory disturbance.

Lesions identified on T2*-weighted gradient echo images in two patients with suspected diffuse axonal injury that resolved in less than ten days

T2*-weighted gradient echo (GE) imaging is useful for detection of intracranial hemorrhage in the patients with diffusion axonal injury (DAI). However, the temporal changes in the DAI-related lesions on T2*-weighted GE images are not clear. We report two very rare cases with DAI in which lesions identified on T2*-weighted GE images resolved in less than ten days.

Developmental change and function of chondroitin sulfate deposited around cerebellar Purkinje cells

Chondroitin sulfate is a long sulfated polysaccharide with enormous structural heterogeneity that binds with various proteins, such as growth factors, in a structure-dependent manner. In this study, we analyzed the expression of chondroitin sulfate in the postnatally developing cerebellar cortex by using three monoclonal antibodies against chondroitin sulfate, MO-225, 2H6, and CS-56, which recognize different structural domains in this polysaccharide. During the first postnatal week, the patterns of immunohistochemical staining made by these antibodies were quite similar, and the molecular layer, the granule cell layer, and Bergmann glial fibers in the external granular layer were densely stained. After postnatal day 12 (P12), the expression of 2H6 epitopes was down-regulated in the molecular layer, and the expression of CS-56 epitopes in this layer was also reduced after P16. On the other hand, the strong expression of MO-225 epitopes, GlcA(2S)beta1-3GalNAc(6S) (D unit)-containing structures, remained until adulthood. These chondroitin sulfate epitopes were observed around Purkinje cells, including cell soma and dendrites. Detailed immunohistochemical analysis suggested that chondroitin sulfate was deposited between Purkinje cell surfaces and the processes of Bergmann glia. Furthermore, the amount of pleiotrophin, a heparin-binding growth factor, in the cultured cerebellar slices was remarkably diminished after treatment with chondroitinase ABC or D unit-rich chondroitin sulfate. With the previous findings that pleiotrophin binds to D unit-rich chondroitin sulfate, we suggest that the D-type structure is important for the signaling of pleiotrophin, which plays roles in Purkinje cell-Bergmann glia interaction, and that the structural changes of chondroitin sulfate regulate this signaling pathway.

2D Thick-section MR digital subtraction angiography for the assessment of dural arteriovenous fistulas

BACKGROUND AND PURPOSE

Although dynamic contrast-enhanced MR angiography studies for arteriovenous malformations (AVFs) and brain tumors have shown promising results, no formal attempt has yet been made to similarly evaluate dural AVFs. To assess the practical applicability of 2D thick-section contrast enhanced MR digital subtraction angiography (MRDSA) for the diagnosis and management of dural AVFs, MRDSA and intra-arterial digital subtraction angiography (IADSA) were comparatively evaluated.

METHODS

We performed 80 consecutive MRDSA studies for 25 dural AVFs, including 11 cavenous sinuses, 9 sigmoid sinuses, 2 tentorial sinuses, one anterior condylar vein, one craniocervical junction, and one spine. MR images were continuously obtained following the initiation of a bolus injection of gadrinium chelates and subtraction images were constructed. We thereafter evaluated the imaging quality and hemodynamic information from all 46 MRDSA images performed in parallel with IADSA in either perioperative or follow-up studies.

RESULTS

Most MRDSA images detected early venous filling, sinus occlusion, leptomeningeal venous drainage, and varices. It was difficult, however, to identify the feeding arteries because of both the partial volume effect and a low spatial resolution. Most important, MRDSA accurately detected aggressive lesions with leptomeningeal venous drainage and varices.

CONCLUSION

Our MRDSA technique was found to have limited value for depicting all the anatomic details of dural AVFs, though it was able to identify important hemodynamic abnormalities related to the risk of hemorrhaging. MRDSA is therefore useful as a less invasive, dynamic angiographic tool, not only for perioperative studies but also for follow-up studies.

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."