Measurement accuracy of a microwave doppler sensor beneath the mattress as a continuous respiratory rate monitor: a method comparison study

PURPOSE

Non-contact continuous respiratory rate monitoring is preferred for early detection of patient deterioration. However, this technique is under development; a gold standard respiratory monitor has not been established. Therefore, this prospective observational method comparison study aimed to compare the measurement accuracy of a non-contact continuous respiratory rate monitor, a microwave Doppler sensor positioned beneath the mattress, with that of other monitors.

METHODS

The respiratory rate of intensive care unit patients was simultaneously measured using a microwave Doppler sensor, capnography, thoracic impedance pneumography, and a piezoelectric sensor beneath the mattress. Bias and 95% limits of agreement between the respiratory rate measured using capnography (standard reference) and that measured using the other three methods were calculated using Bland-Altman analysis for repeated measures. Clarke error grid (CEG) analysis evaluated the sensor's ability to assist in correct clinical decision-making.

RESULTS

Eighteen participants were included, and 2,307 data points were analyzed. The bias values (95% limits of agreement) of the microwave Doppler sensor, thoracic impedance pneumography, and piezoelectric sensor were 0.2 (- 4.8 to 5.2), 1.5 (- 4.4 to 7.4), and 0.4 (- 4.0 to 4.8) breaths per minute, respectively. Clinical decisions evaluated using CEG analyses were correct 98.1% of the time for the microwave Doppler sensor, which was similar to the performance of the other devices.

CONCLUSION

The microwave Doppler sensor had a small bias but relatively low precision, similar to other devices. In CEG analyses, the risk of each monitor leading to inadequate clinical decision-making was low.

TRIAL REGISTRATION NUMBER

UMIN000038900, February 1, 2020.

Defining the Standard of the Terminology of the Mechanical Ventilation Data in Japan

To effectively use data from intensive care unit patient information systems at multiple hospitals, it is necessary to standardize the data into a well-ordered form. However, terms often vary between devices. We designed a mechanical ventilation concept model and applied data to that model using existing tools and expert opinions. The JSICM glossary was revised based on this study.

Post-intensive care syndrome: Recent advances and future directions

Post-intensive care syndrome comprises physical, cognitive, and mental impairments in patients treated in an intensive care unit (ICU). It occurs either during the ICU stay or following ICU discharge and is related to the patients' long-term prognosis. The same concept also applies to pediatric patients, and it can greatly affect the mental status of family members. In the 10 years since post-intensive care syndrome was first proposed, research has greatly expanded. Here, we summarize the recent evidence on post-intensive care syndrome regarding its pathophysiology, epidemiology, assessment, risk factors, prevention, and treatments. We highlight new topics, future directions, and strategies to overcome post-intensive care syndrome among people treated in an ICU. Clinical and basic research are still needed to elucidate the mechanistic insights and to discover therapeutic targets and new interventions for post-intensive care syndrome.

Creatinine Reduction Ratio Is a Prognostic Factor for Acute Kidney Injury following Cardiac Surgery with Cardiopulmonary Bypass: A Single-Center Retrospective Cohort Study

Acute kidney injury (AKI) after cardiac surgery is a common complication that can lead to death. We previously reported that the creatinine reduction ratio (CRR) serves as a useful prognostic factor for AKI. The primary objective of this study was to determine the predictors of AKI after surgery. The secondary objective was to determine the reliability of the CRR for short- and long-term outcomes. We retrospectively collected information about cardiac surgery patients who underwent cardiopulmonary bypass. Patients were divided into AKI and non-AKI groups based on the AKIN and RIFLE criteria. We analyzed the two groups regarding the preoperative patient data and operative information. The CRR was calculated as follows: (preoperative creatinine-postoperative creatinine)/preoperative creatinine. The prognostic factors of AKI-CS were surgery time, CPB time, aorta clamp time, platelet transfusion, and CRR < 20%. In the multivariate logistical analysis, CRR was an independent predictor of AKI (adjusted odds ratio: 0.90 [0.87-0.93], p < 0.001). However, there were no significant differences in CRR in terms of the rate of new onset chronic kidney disease (CKD). After cardiac surgery with cardiopulmonary bypass, CRR has good diagnostic power for predicting perioperative AKI. However, we cannot use it as a prognostic factor over a long-term period.

Instruments to assess post-intensive care syndrome assessment: a scoping review and modified Delphi method study

BACKGROUND

The assessment of post-intensive care syndrome (PICS) is challenging due to the numerous types of instruments. We herein attempted to identify and propose recommendations for instruments to assess PICS in intensive care unit (ICU) survivors.

METHODS

We conducted a scoping review to identify PICS follow-up studies at and after hospital discharge between 2014 and 2022. Assessment instruments used more than two times were included in the modified Delphi consensus process. A modified Delphi meeting was conducted three times by the PICS committee of the Japanese Society of Intensive Care Medicine, and each score was rated as not important (score: 1-3), important, but not critical (4-6), and critical (7-9). We included instruments with ≥ 70% of respondents rating critical and ≤ 15% of respondents rating not important.

RESULTS

In total, 6972 records were identified in this scoping review, and 754 studies were included in the analysis. After data extraction, 107 PICS assessment instruments were identified. The modified Delphi meeting reached 20 PICS assessment instrument recommendations: (1) in the physical domain: the 6-min walk test, MRC score, and grip strength, (2) in cognition: MoCA, MMSE, and SMQ, (3) in mental health: HADS, IES-R, and PHQ-9, (4) in the activities of daily living: the Barthel Index, IADL, and FIM, (5) in quality of life: SF-36, SF-12, EQ-5D-5L, 3L, and VAS (6), in sleep and pain: PSQI and Brief Pain Inventory, respectively, and (7) in the PICS-family domain: SF-36, HADS, and IES-R.

CONCLUSION

Based on a scoping review and the modified Delphi method, 20 PICS assessment instruments are recommended to assess physical, cognitive, mental health, activities of daily living, quality of life, sleep, and pain in ICU survivors and their families.

Impact of Persistent Inflammation, Immunosuppression, and Catabolism Syndrome during Intensive Care Admission on Each Post-Intensive Care Syndrome Component in a PICS Clinic

BACKGROUND

Persistent inflammation, immunosuppression, and catabolism syndrome (PIICS) is known as a prolonged immunodeficiency that occurs after severe infection. Few studies have demonstrated a direct relationship between PIICS and physical dysfunction in post-intensive care syndrome (PICS). We herein investigated how each component of PICS was affected by the diagnosis of PIICS during hospitalization and examined the relationship between PIICS and PICS using PICS assessments performed at the Hitachi General Hospital PICS Clinic.

METHODS

The 273 patients who visited the PICS clinic at one month after discharge from the ICU at Hitachi General Hospital were included in the study. We used the diagnostic criteria for PIICS described in previous studies. At least two of the following blood test values on day 14 of hospitalization had to be met for a diagnosis of PIICS: C-reactive protein (CRP) > 2.0 mg/dL, albumin (Alb) < 3.0 g/dL, and lymphocytes (Lym) < 800/μL. Blood test values closest to day 14 out of 11-17 days of hospitalization were used. The primary outcome was a Barthel Index (BI) < 90, while secondary outcomes were the results of various PICS assessments, including mental and cognitive impairments, performed at the PICS clinic. We supplemented missing data with multiple imputations by chained equations. We performed a nominal logistic regression analysis with age, sex, BMI, SOFA, and the presence of PIICS as variables for BI < 90.

RESULTS

Forty-three out of two hundred seventy-three PICS outpatients met the diagnostic criteria for PIICS during hospitalization. In comparisons with non-PIICS patients, significantly higher severity scores for APACHE II and SOFA and a longer hospital stay were observed in PIICS patients, suggesting a higher clinical severity. The primary outcome, BI, was lower in the PIICS group (97.5 (58.5, 100) vs. 100 (95, 100), p = 0.008), as were the secondary outcomes (FSS-ICU: 35 (31, 35) vs. 35 (35, 35), MRC score: 55 (50.25, 58) vs. 58 (53, 60), grip strength: 16.45 (9.2, 25.47) vs. 20.4 (15.3, 27.7)). No significant differences were noted in mental or cognitive function assessments, such as HADS, IES-R, and SMQ. A multivariable analysis supplemented with missing data revealed that PIICS (odds ratio: 1.23 (1.08-1.40 p = 0.001) and age (odds ratio: 1.007 (1.004-1.01), p < 0.001) correlated with BI < 90, independent of clinical severity such as sequential organ failure assessment (SOFA). Similar results were obtained in the sensitivity analysis excluding missing data.

CONCLUSIONS

The present study revealed a strong relationship between PIICS and post-discharge PICS physical dysfunction in patients requiring intensive care.

Stomach position evaluated using computed tomography is related to successful post-pyloric enteral feeding tube placement in critically ill patients: a retrospective observational study

BACKGROUND

Post-pyloric enteral feeding reduces respiratory complications and shortens the duration of mechanical ventilation. Blind placement of post-pyloric enteral feeding tubes (EFT) in patients with critical illnesses is often the first-line method because endoscopy or fluoroscopy cannot be easily performed at bedside; however, difficult placements regularly occur. We reported an association between the stomach position caudal to spinal level L1-L2, evaluated by abdominal radiographs after placement, and difficult placement; however, this method could not indicate difficulty before EFT placement. The aim of our study was to evaluate the association between stomach position, estimated using computed tomography (CT) images taken before the blind placement of the post-pyloric EFT, and the difficulty of EFT placement.

METHODS

Data from patients aged ≥ 20 years who underwent post-pyloric EFT in our intensive care unit were obtained retrospectively. Logistic regression analysis was used to evaluate the association between successful initial EFT placement and explanatory variables, including stomach position estimated by CT. Two cut-off values were used: caudal to L1-L2 based on a previous study and the best cut-off value calculated by the receiver operating characteristic curve. Variable selection was performed backward stepwise using Akaike's Information Criterion.

RESULTS

Of the total of 453 patients who were enrolled, the success rate of the initial EFT placement was 43.5%. The adjusted odds ratio for successful initial EFT placement of the stomach position caudal to L1-L2 was 0.61 (95% confidence interval: 0.41-1.07). Logistic regression analysis, including the stomach position caudal to L2-L3, calculated as the best cut-off value, indicated that stomach position was an independent factor for failure of initial EFT placement (adjusted odds ratio, 0.55; 95% confidence interval: 0.33-0.91).

CONCLUSIONS

Stomach position evaluated using CT images was associated with successful initial post-pyloric EFT placement. The best cut-off value of the greater curvature of the stomach to predict the success or failure of the first attempt was spinal level L2-L3. Trial registration University Hospital Medical Information Network Clinical Trials Registry (UMIN000046986; February 28, 2022). https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000052151.

Epidemiology and outcomes of hospital-acquired bloodstream infections in intensive care unit patients: the EUROBACT-2 international cohort study

PURPOSE

In the critically ill, hospital-acquired bloodstream infections (HA-BSI) are associated with significant mortality. Granular data are required for optimizing management, and developing guidelines and clinical trials.

METHODS

We carried out a prospective international cohort study of adult patients (≥ 18 years of age) with HA-BSI treated in intensive care units (ICUs) between June 2019 and February 2021.

RESULTS

2600 patients from 333 ICUs in 52 countries were included. 78% HA-BSI were ICU-acquired. Median Sequential Organ Failure Assessment (SOFA) score was 8 [IQR 5; 11] at HA-BSI diagnosis. Most frequent sources of infection included pneumonia (26.7%) and intravascular catheters (26.4%). Most frequent pathogens were Gram-negative bacteria (59.0%), predominantly Klebsiella spp. (27.9%), Acinetobacter spp. (20.3%), Escherichia coli (15.8%), and Pseudomonas spp. (14.3%). Carbapenem resistance was present in 37.8%, 84.6%, 7.4%, and 33.2%, respectively. Difficult-to-treat resistance (DTR) was present in 23.5% and pan-drug resistance in 1.5%. Antimicrobial therapy was deemed adequate within 24 h for 51.5%. Antimicrobial resistance was associated with longer delays to adequate antimicrobial therapy. Source control was needed in 52.5% but not achieved in 18.2%. Mortality was 37.1%, and only 16.1% had been discharged alive from hospital by day-28.

CONCLUSIONS

HA-BSI was frequently caused by Gram-negative, carbapenem-resistant and DTR pathogens. Antimicrobial resistance led to delays in adequate antimicrobial therapy. Mortality was high, and at day-28 only a minority of the patients were discharged alive from the hospital. Prevention of antimicrobial resistance and focusing on adequate antimicrobial therapy and source control are important to optimize patient management and outcomes.

Multivariate analysis of factors associated with first-pass success in blind placement of a post-pyloric feeding tube: a retrospective study

BACKGROUND

Trans-jejunal nutrition via a post-pyloric enteral feeding tube has a low risk of aspiration or reflux; however, placement of the tube using the blind method can be difficult. Assistive devices, such as fluoroscopy or endoscopy, are useful but may not be suitable for patients with hemodynamic instability or severe respiratory failure. The aim of this study was to explore factors associated with first-pass success in the blind placement of post-pyloric enteral feeding tubes in critically ill patients.

METHODS

Data were obtained retrospectively from the medical records of adult patients who had a post-pyloric enteral feeding tube placed in the intensive care unit between January 1, 2012, and December 31, 2018. Logistic regression analysis was performed to assess the association between first-pass success and the independent variables. For logistic regression analysis, the following 13 variables were defined as independent variables: age, sex, height, fluid balance from baseline, use of sedatives, body position during the procedure, use of cardiac assist devices, use of prokinetic agents, presence or absence of intestinal peristalsis, postoperative cardiovascular surgery, use of renal replacement therapy, serum albumin levels, and position of the greater curvature of the stomach in relation to spinal levels L1 - L2.

RESULTS

Data obtained from 442 patients were analyzed. The first-pass success rate was 42.8% (n = 189). Logistic regression analysis demonstrated that the position of the greater curvature of the stomach cephalad to L1 - L2 was only associated with successful placement (odds ratio for first-pass success, 0.62; 95% confidence interval: 0.40 - 0.95).

CONCLUSIONS

In critically ill patients, the position of the greater curvature of the stomach caudal to L1 - L2 may be associated with a lower first-pass success rate of the blind method for post-pyloric enteral feeding tube placement. Further studies are needed to verify our results because the position of the stomach was estimated by radiographs after enteral feeding tube placement.

TRIAL REGISTRATION

University Hospital Medical Information Network Clinical Trials Registry (UMIN000036549; April 20, 2019).

Evaluation of respiratory rate monitoring using a microwave Doppler sensor mounted on the ceiling of an intensive care unit: a prospective observational study

Continuous monitoring of the respiratory rate is crucial in an acute care setting. Contact respiratory monitoring modalities such as capnography and thoracic impedance pneumography are prone to artifacts, causing false alarms. Moreover, their cables can restrict patient behavior or interrupt patient care. A microwave Doppler sensor is a novel non-contact continuous respiratory rate monitor. We compared respiratory rate measurements performed with a microwave Doppler sensor mounted on the ceiling of an intensive care unit with those obtained by conventional methods in conscious and spontaneously breathing patients. Participants' respiratory rate was simultaneously measured by visual counting of chest wall movements for 60 s; a microwave Doppler sensor; capnography, using an oxygen mask; and thoracic impedance pneumography, using electrocardiogram electrodes. Bland-Altman analysis for repeated measures was performed to calculate bias and 95% limits of agreement between the respiratory rate measured by visual counting (reference) and that measured by each of the other methods. Among 52 participants, there were 336 (microwave Doppler sensor), 275 (capnography), and 336 (thoracic impedance pneumography) paired respiratory rate data points. Bias (95% limits of agreement) estimates were as follows: microwave Doppler sensor, 0.3 (- 6.1 to 6.8) breaths per minute (bpm); capnography, - 1.3 (- 8.6 to 6.0) bpm; and thoracic impedance pneumography, 0.1 (- 4.4 to 4.7) bpm. Compared to visual counting, the microwave Doppler sensor showed small bias; however, the limits of agreement were similar to those observed in other conventional methods. Our monitor and the conventional ones are not interchangeable with visual counting.Trial registration number: UMIN000032021, March/30/2018.

Conventional risk prediction models fail to accurately predict mortality risk among patients with coronavirus disease 2019 in intensive care units: a difficult time to assess clinical severity and quality of care

Since the start of the coronavirus disease 2019 (COVID-19) pandemic, it has remained unknown whether conventional risk prediction tools used in intensive care units are applicable to patients with COVID-19. Therefore, we assessed the performance of established risk prediction models using the Japanese Intensive Care database. Discrimination and calibration of the models were poor. Revised risk prediction models are needed to assess the clinical severity of COVID-19 patients and monitor healthcare quality in ICUs overwhelmed by patients with COVID-19.

Development and validation of the predictive risk of death model for adult patients admitted to intensive care units in Japan: an approach to improve the accuracy of healthcare quality measures

BACKGROUND

The Acute Physiology and Chronic Health Evaluation (APACHE) III-j model is widely used to predict mortality in Japanese intensive care units (ICUs). Although the model's discrimination is excellent, its calibration is poor. APACHE III-j overestimates the risk of death, making its evaluation of healthcare quality inaccurate. This study aimed to improve the calibration of the model and develop a Japan Risk of Death (JROD) model for benchmarking purposes.

METHODS

A retrospective analysis was conducted using a national clinical registry of ICU patients in Japan. Adult patients admitted to an ICU between April 1, 2018, and March 31, 2019, were included. The APACHE III-j model was recalibrated with the following models: Model 1, predicting mortality with an offset variable for the linear predictor of the APACHE III-j model using a generalized linear model; model 2, predicting mortality with the linear predictor of the APACHE III-j model using a generalized linear model; and model 3, predicting mortality with the linear predictor of the APACHE III-j model using a hierarchical generalized additive model. Model performance was assessed with the area under the receiver operating characteristic curve (AUROC), the Brier score, and the modified Hosmer-Lemeshow test. To confirm model applicability to evaluating quality of care, funnel plots of the standardized mortality ratio and exponentially weighted moving average (EWMA) charts for mortality were drawn.

RESULTS

In total, 33,557 patients from 44 ICUs were included in the study population. ICU mortality was 3.8%, and hospital mortality was 8.1%. The AUROC, Brier score, and modified Hosmer-Lemeshow p value of the original model and models 1, 2, and 3 were 0.915, 0.062, and < .001; 0.915, 0.047, and < .001; 0.915, 0.047, and .002; and 0.917, 0.047, and .84, respectively. Except for model 3, the funnel plots showed overdispersion. The validity of the EWMA charts for the recalibrated models was determined by visual inspection.

CONCLUSIONS

Model 3 showed good performance and can be adopted as the JROD model for monitoring quality of care in an ICU, although further investigation of the clinical validity of outlier detection is required. This update method may also be useful in other settings.

The Difference Between Set and Delivered Tidal Volume: A Lung Simulation Study

Background

Precise control of tidal volume is one of the keys in limiting ventilator-induced lung injury and ensuring adequate ventilation in mechanically ventilated neonates. The aim of the study was to compare the tidal volume (mVT) measured from the expiratory limb of the ventilator with the actual tidal volume (aVT) that would be delivered to the patient using a lung model to simulate a neonate.

Methods

This study was conducted using the ASL5000 lung simulator. Three combinations of parameters were set: resistance (cmH₂O/L/sec) and compliance (mL/cmH₂O) of 50 and 2 (Group 1), 100 and 1 (Group 2), and 150 and 0.5 (Group 3), respectively. The ASL5000 was connected to each of the ventilators including one anesthesia machine ventilator (Drager Fabius GS) and two ICU ventilators (Servo-i Universal and Evita Infinity V500). Each ventilator was evaluated with a set tidal volume of 30 mL (sVT) and a respiratory rate of 25 breathes/minute in both the volume-controlled ventilation (VCV) and dual-controlled ventilation (DCV) modes.

Results

The discrepancies between sVT, mVT and aVT were highest with the Fabius anesthesia machine ventilator and increased in the simulated lung injury groups. When comparing the ICU ventilators, the difference was greater the Servo-i and increased when using the DCV mode and with simulated lung injury.

Conclusion

Accurate tidal volumes were achieved only with the Infinity ICU ventilator. This was true regardless of mode of ventilation and even during simulated lung injury.

A question is "what are the optimal targets for anticoagulant therapies?"

A high mortality rate is found among septic patients with disseminated intravascular coagulation (DIC). Anticoagulants have been used for treating septic DIC especially in Japanese clinical settings; however, their effectiveness is quite controversial across studies. According to several randomized controlled trials and meta-analyses, antithrombin and recombinant thrombomodulin had no therapeutic benefit in the treatment of sepsis. However, the majority of the previous research did not discuss “septic DIC” but simply “sepsis”, and some reviews showed that anticoagulants were benefit only in septic DIC. Although immunothrombosis plays an important role in early host defense, it can lead to DIC and organ failure if dysregulated. Therefore, we advocate anticoagulant therapies might have beneficial effects, but research on optimal patient selection is currently lacking.

Low hematocrit levels: a risk factor for long-term outcomes in patients requiring prolonged mechanical ventilation after cardiovascular surgery. A retrospective study

While low-risk patients who undergo elective surgery can tolerate low hematocrit levels, the benefits of higher hematocrit levels might outweigh the risk of transfusion in high-risk patients. Therefore, this study aimed to evaluate the effects of perioperative hematocrit levels on mortality in patients requiring prolonged mechanical ventilation (PMV) after a cardiovascular surgery. This single-center retrospective cohort study was conducted on 172 patients who underwent cardiovascular surgery with cardiopulmonary bypass or off-pump coronary artery bypass grafting and required PMV for ≥72 hours in the intensive care unit (ICU) from 2008 to 2012 at the Yokohama City University Medical Center in Yokohama, Japan. Patients were classified according to hematocrit levels on ICU admission: high (≥30%) and low (<30%) groups. Of 172 patients, 86 were included to each of the low-hematocrit and high-hematocrit groups, with median hematocrit levels (first to third quartiles) of 27.4% (25.4%–28.7%) and 33.0% (31.3%–35.5%), respectively. The difference in survival rates was significant between the two groups using the log-rank test (HR 0.55, 95% CI 0.32 to 0.95, p=0.033). Cox regression analysis revealed that ≥30% increase in hematocrit levels on ICU admission was significantly associated with decreased long-term mortality (HR 0.40, 95% CI 0.20 to 0.80, p=0.0095). Lower hematocrit levels on ICU admission was a risk factor for increased long-term mortality, and higher hematocrit levels might outweigh the risk of transfusion in patients requiring PMV after a cardiovascular surgery.

The perfusion index measured by the pulse oximeter affects the agreement between ClearSight and the arterial catheter-based blood pressures: A prospective observational study

Background

ClearSight is a noninvasive arterial blood pressure monitor, but it remains unknown whether it is affected by the state of perfusion to the fingers. We investigated whether the lower perfusion index (PI) measured with a pulse oximeter, which reflects finger perfusion, would affect the agreement between arterial pressures measured with ClearSight versus those obtained with an arterial catheter.

Methods

Paired arterial pressure data (ClearSight and arterial catheter-based pressures) and PI values were prospectively obtained from 30 patients undergoing major abdominal surgery. The primary outcome was standard deviation (SD) of the bias (precision) of blood pressure between ClearSight and arterial catheter. The ratio of the adjusted SD of the bias between PI≤1 and PI>1 was calculated using the linear mixed-effects model. The secondary outcomes were the bias and the limits of agreement (LOA) between the two devices (repeated measures Bland-Altman analysis).

Results

We analyzed 6312 paired data points. The adjusted SD of bias in PI ≤1 compared with those in PI >1 was 1.4-fold (95% confidence interval: 1.3- to 1.4-fold) for systolic arterial pressure, 1.5-fold (95% confidence interval: 1.3- to 1.6-fold) for diastolic arterial pressure, and 1.3-fold (95% confidence interval: 1.2- to 1.5-fold) for mean arterial pressure. The bias (LOA) were as follows: systolic arterial pressure in the PI ≤1 and PI >1 groups, -3.5 (-35.4 to 28.4) mmHg and 2.2 (-19.9 to 24.3) mmHg, respectively; diastolic arterial pressure in the PI ≤1 and PI >1 groups, 13.1 (-5.1 to 31.3) mmHg and 9.0, (-2.6 to 20.6) mmHg, respectively; and mean arterial pressure in the PI ≤1 and PI >1 groups, 8.7 (-11.3 to 28.7) mmHg and 7.6 (-6.2 to 21.3) mmHg, respectively.

Conclusions

PI ≤1 was associated with a large SD of the bias between the devices. The PI value could be a real-time indicator of ClearSight precision.

A rapid shallow breathing index threshold of 85 best predicts extubation success in chronic obstructive pulmonary disease patients with hypercapnic respiratory failure

Background

The rapid shallow breathing index (RSBI) is used clinically to help predict a patient's likelihood of successful liberation from mechanical ventilation (MV). However, the traditional threshold (<105 breaths/min/L) may underperform in patients with chronic obstructive pulmonary disease (COPD). We sought to determine the optimal RSBI threshold for COPD patients to improve the diagnostic accuracy for predicting successful ventilator liberation.

Methods

This was a prospective observational multicenter study of COPD patients [according to Global initiative for Chronic Obstructive Lung Disease (GOLD) criteria] admitted to the Medical ICUs of eight academic medical centers. All patients were intubated for hypercapnic respiratory failure and met the American Thoracic Society/European Respiratory Society guidelines to participate in a weaning trial. Ventilator weaning was conducted according to a defined protocol. RSBI was measured through the ventilator after 120 minutes of spontaneous breathing trial (SBT).

Results

Ninety patients were included (39 males and 51 females). Forty-three patients (48%) were successfully extubated whereas 47 patients (52%) failed extubation. Significant differences were observed between groups for duration-of-intubation [duration of intubation (DoI); P<0.0001], spontaneous tidal volume (VT) (P=0.03), and the ratio of dynamic-to-static compliance (P=0.005). The RSBI threshold of ≤85 breaths/min/L performed best: area under curve (AUC) receiver operating characteristic (ROC) curves 0.91, sensitivity 95.6%, specificity 90.4%, positive predictive value (PPV) 95.5%, and negative predictive value (NPV) 90.6%., positive likelihood ratio (LR+) 5.48, negative likelihood ratio (LR-) 0.25, and the diagnostic accuracy 91.7%. In post-ROC analyses, DoI and hospital length-of-stay (LOS) did not impact performance.

Conclusions

In COPD patients intubated with hypercapnia, RSBI ≤85 breaths/min/L outperformed the widely used threshold <105 breaths/min/L, yielding a 95.5% probability of extubation success, independent of ventilation duration or hospital LOS.

Hyperleukocytosis Complicated by Intracerebral Hemorrhage and Spurious Hypoxemia: A Case Report and Literature Review

We present the management of a 15-year-old girl with acute myeloid leukemia who presented with massive hyperleukocytosis and neurological deficit due to intracerebral hemorrhage. Surgical intervention was considered but ultimately not undertaken because of the presence of massive hyperleukocytosis, thrombocytopenia, hypokalemia, and considerable discrepancy between the oxygen saturation values determined mechanically and by peripheral oximetry. Aggressive treatment of the hyperleukocytosis was immediately started, which improved the patient's overall condition and rendered surgical intervention unnecessary. This report shows that immediate treatment of massive hyperleukocytosis and critical interpretation of laboratory results in patients with hyperleukocytosis are warranted.

Low prevalence of the 'gang of seven' and absence of the O80:H2 serotypes among Shigatoxigenic and enteropathogenic Escherichia coli (STEC and EPEC) in intestinal contents of healthy cattle at two slaughterhouses in Belgium in 2014

AIMS

The purpose of this survey was to estimate the respective prevalence of the 'gang of seven' and 'non-gang of seven' serotypes of Shigatoxigenic and enteropathogenic Escherichia coli and to identify the O80:H2 serotype in 245 intestinal contents collected at two slaughterhouses in Belgium in 2014.

METHODS AND RESULTS

After overnight enrichment growth, the 69 intestinal contents testing positive with PCR targeting the eae, stx1 and stx2 genes were inoculated onto four agar media. Of the 2542 colonies picked up, 677 from 59 samples were PCR confirmed. The most frequent virulotypes were eae+ in 47 (80%) samples, stx2+ in 20 (34%) samples and eae+ stx1+ in 16 (27%) samples. PCR-positive colonies belonged to different virulotypes in 36 samples. No colony was O80-positive, whereas two eae+ colonies from two samples were O26:H11, 50 eae+ stx1+ and eae+ from eight samples were O103:H2 and two eae+ stx1+ stx2+ colonies from one sample were O157:H7.

CONCLUSIONS

The 'non-gang of seven' serotypes are more frequent than the 'gang of seven' serotypes and the O80:H2 serotype was not detected among Shigatoxigenic and enteropathogenic Escherichia coli in the intestines of cattle at these two slaughterhouses.

SIGNIFICANCE AND IMPACT OF THE STUDY

Although the identification protocols of Shigatoxigenic Escherichia coli focus on the 'gang of seven' serotypes, several other serotypes can be present with possible importance in public health. Innovative selective identification procedures should be designed.

Predictors of severe postoperative hyperglycemia after cardiac surgery in infants: a single-center, retrospective, observational study

PURPOSE

Hyperglycemia is a common issue in infants after cardiac surgery for congenital heart disease. Poor glycemic control is suspected to be associated with adverse postoperative outcomes. This study was performed to investigate clinical factors contributing to hyperglycemia in the perioperative period in infats.

METHODS

A total of 69 infants (aged 1-12 months) who were admitted to Yokohama City University Hospital Intensive Care Unit (ICU) after surgical repair of congenital heart diseases with cardiopulmonary bypass (CPB) were retrospectively analysed. Hyperglycemia was defined as blood glucose ≥ 250 mg/dL on ICU admission. Clinical background, operative factors, and postoperative factors were compared between the hyperglycemic and non-hyperglycemic groups. Additionally, multivariate analysis was performed to identify factors contributing to hyperglycemia.

RESULTS

Nineteen (27.5%) and 50 (72.5%) infants were classified into the hyperglycemic and non-hyperglycemic groups, respectively. Hyperglycemic infants were significantly younger, shorter, and weighed less, with a higher rate of chromosomal abnormalities. Intraoperatively, they also experienced longer CPB and surgery times and had higher peak lactate levels and higher inotropic requirements. Hyperglycemia was related to longer mechanical ventilation and longer ICU stays. Multivariate analysis detected intraoperative hyperglycemia, longer CPB time, younger age and chromosomal abnormality as significant factors.

CONCLUSION

Adding to hyperglycemia during the operation, longer CPB time younger age and chromosomal abnormality were identified as predictors of high blood glucose levels at ICU admission.

Inhibition of Prolyl Hydroxylase Attenuates Fas Ligand-Induced Apoptosis and Lung Injury in Mice

Alveolar epithelial injury and increased alveolar permeability are hallmarks of acute respiratory distress syndrome. Apoptosis of lung epithelial cells via the Fas/Fas ligand (FasL) pathway plays a critical role in alveolar epithelial injury. Activation of hypoxia-inducible factor (HIF)-1 by inhibition of prolyl hydroxylase domain proteins (PHDs) is a possible therapeutic approach to attenuate apoptosis and organ injury. Here, we investigated whether treatment with dimethyloxalylglycine (DMOG), an inhibitor of PHDs, could attenuate Fas/FasL-dependent apoptosis in lung epithelial cells and lung injury. DMOG increased HIF-1α protein expression in vitro in MLE-12 cells, a murine alveolar epithelial cell line. Treatment of MLE-12 cells with DMOG significantly suppressed cell surface expression of Fas and attenuated FasL-induced caspase-3 activation and apoptotic cell death. Inhibition of the HIF-1 pathway by echinomycin or small interfering RNA transfection abolished these antiapoptotic effects of DMOG. Moreover, intraperitoneal injection of DMOG in mice increased HIF-1α expression and decreased Fas expression in lung tissues. DMOG treatment significantly attenuated caspase-3 activation, apoptotic cell death in lung tissue, and the increase in alveolar permeability in mice instilled intratracheally with FasL. In addition, inflammatory responses and histopathological changes were also significantly attenuated by DMOG treatment. In conclusion, inhibition of PHDs protects lung epithelial cells from Fas/FasL-dependent apoptosis through HIF-1 activation and attenuates lung injury in mice.

Deep Breathing Improves End-Tidal Carbon Dioxide Monitoring of an Oxygen Nasal Cannula-Based Capnometry Device in Subjects Extubated After Abdominal Surgery

BACKGROUND

Capnometry detects hypoventilation earlier than pulse oximetry while supplemental oxygen is being administered. We compared the end-tidal CO₂ (P_ETCO2 ) measured using a newly developed oxygen nasal cannula with a CO₂-sampling port and the P_aCO2 in extubated subjects after abdominal surgery. We also investigated whether the difference between P_aCO2 and P_ETCO2 is affected by resting, by spontaneous breathing with the mouth consciously closed, and by deep breathing with the mouth closed.

METHODS

Adult post-abdominal surgery subjects admitted to the ICU were enrolled. After extubation, oxygen was supplied at 4 L/min using a capnometry-type oxygen cannula. The breathing frequency, P_ETCO2 , and P_aCO2 were measured after 30 min of oxygen supplementation. P_ETCO2 was continuously measured during rest, during breathing with the mouth consciously closed, and during deep breathing with the mouth closed. The difference between P_ETCO2 and P_aCO2 during various breathing patterns was analyzed using the Bland-Altman method.

RESULTS

Twenty subjects were included. The bias ± SD (limits of agreement) for breathing frequency measured by capnometry compared with those obtained by direct measurement was 0.4 ± 3.6 (-6.7 to 7.4). In P_ETCO2 compared with P_aCO2 , the biases (limits of agreement) were 14.8 ± 8.2 (-1.3 to 30.9) at rest, 10.2 ± 6.4 (-2.3 to 22.7) with the mouth closed, and 7.7 ± 5.6 (-3.2 to 18.6) for deep breathing with the mouth closed. P_ETCO2 determined using the capnometry device yielded unreliable and widely ranging values under various breathing patterns. However, deep breathing with the mouth closed decreased the difference between P_ETCO2 and P_aCO2 , as compared with other breathing patterns.

CONCLUSIONS

P_ETCO2 measurements under deep breathing with mouth closed with a capnometry-type oxygen cannula improved the prediction of the absolute value of P_aCO2 in extubated post-abdominal surgical subjects without respiratory dysfunction.

[Difference in the Spread of Injectate between Ultrasound Guided Pectoral Nerve Block I and II. A Cadaver Study]

BACKGROUND

Pectoral nerve block (PECS block) is first reported by Blanco et al, and mainly used for analgesia for breast surgery in Japan. However, the spread of PECS block is unclear.

METHODS

Ultrasound guided PECS I and II blocks were performed in a cadaver, and the cadaver was dissected for evaluation of the spread of coloring matter.

RESULTS

The coloring matter by PECS I block was spread to the axillary region between the major and minor pectoral muscles, while PECS II block remained over the fascia of the serratus muscle from mid-clavicular line to middle axillary line. Two possible routes to the axillary region by PECS I include: dorsal to the pectoral minor muscle through the clavipectoral fascia, and over the pectoral minor muscle to the axillary sheath.

CONCLUSIONS

Our cadaveric evaluation suggests that PECS I block produces more analgesia of the axillary region than PECS II. Further evaluation is needed in more cadavers.

Modified rapid shallow breathing index adjusted with anthropometric parameters increases predictive power for extubation failure compared with the unmodified index in postcardiac surgery patients

OBJECTIVE

The aim of this study was to determine the best predictors of successful extubation after cardiac surgery, by modifying the rapid shallow breathing index (RSBI) based on patients' anthropometric parameters.

DESIGN

Single-center prospective observational study.

SETTING

Two general intensive care units at a single research institute.

PARTICIPANTS

Patients who had undergone uncomplicated cardiac surgery.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The following parameters were investigated in conjunction with modification of the RSBI: Actual body weight (ABW), predicted body weight, ideal body weight, body mass index (BMI), and body surface area. Using the first set of patient data, RSBI threshold and modified RSBI for extubation failure were determined (threshold value; RSBI: 77 breaths/min (bpm)/L, RSBI adjusted with ABW: 5.0 bpm×kg/mL, RSBI adjusted with BMI: 2.0 bpm×BMI/mL). These threshold values for RSBI and RSBI adjusted with ABW or BMI were validated using the second set of patient data. Sensitivity values for RSBI, RSBI modified with ABW, and RSBI modified with BMI were 91%, 100%, and 100%, respectively. The corresponding specificity values were 89%, 92%, and 93%, and the corresponding receiver operator characteristic values were 0.951, 0.977, and 0.980, respectively.

CONCLUSIONS

Modified RSBI adjusted based on ABW or BMI has greater predictive power than conventional RSBI.

Impalement oral injury: Ultrasonic scalpel is the best tool to cut off a toothbrush

BACKGROUND/AIM

Penetrating injuries to the oral cavity involving a toothbrush are relatively common among children. Sometimes general anesthesia is recommended. Although the handle prevents adequate mask ventilation in the induction of anesthesia, it is unknown what is the best tool to cut it preventing complications. The aim of this study was to evaluate the optimal tool to cut off the toothbrush handle.

MATERIALS AND METHODS

Six anesthesiologists participated in this study. We attached a triaxial acceleration sensor to the tip of the toothbrush to virtually measure force toward the wound. Each participant cut off the handle of the toothbrush using 3 tools: Gluck rib shears (GRS: cutting horizonal); Sklar Coryllos rib shears (SCRS: cutting vertical); and an ultrasonic scalpel (USS). Acceleration and time required to cut the toothbrush were measured. Each anesthesiologist evaluated the usability of each tool on a 5-point scale.

RESULTS

The USS showed the longest mean time (GRS, 1.78 ± 1.01 s; SCRS, 7.30 ± 4.58 s; USS, 28.13 ± 13.41 s), lowest 3-dimensional acceleration (GRS, 2.15 ± 0.69 G; SCRS, 2.13 ± 0.57 G; USS, 1.01 ± 1.07 G), and highest mean score for usability.

CONCLUSION

The USS appeared preferable to rib shears for cutting off toothbrush handles, even though it takes longer.

Effects of Breathing Pattern on Oxygen Delivery Via a Nasal or Pharyngeal Cannula

BACKGROUND

During sedation for upper gastrointestinal endoscopy, oxygen delivery via a nasal cannula is often necessary. However, the influences of the oxygen delivery route and breathing pattern on the F(IO2) have not been thoroughly investigated. The aim of this simulation study was to investigate the difference in the F(IO2) with a pharyngeal cannula versus nasal cannula during high- or low-tidal volume (V(T)) ventilation and open- or closed-mouth breathing.

METHODS

Six healthy volunteers were asked to breathe using 2 patterns of ventilation (high or low V(T)) via a sealed face mask connected to an endotracheal tube that was retrogradely inserted into the trachea of a mannequin. The mannequin also had a pharyngeal or nasal cannula inserted into the pharynx or attached to the nose, through which oxygen (2 or 5 L/min) was delivered. The mouth of the mannequin was kept open or closed by packing. We measured the F(IO2) of every breath for 1 min at each setting.

RESULTS

During low- and high-V(T) ventilation, the F(IO2) was highest at a flow of 5 L/min with a pharyngeal cannula. Oxygen delivery was higher with the pharyngeal cannula compared with the nasal cannula at all settings. Differences in flow did not result in significant differences in the F(IO2) with high- and low-V(T) ventilation. At a flow of 5 L/min via a pharyngeal cannula, open-mouth breathing resulted in a significantly higher F(IO2) compared with closed-mouth breathing.

CONCLUSIONS

A pharyngeal cannula provided a higher F(IO2) compared with a nasal cannula at the same oxygen flow. Open-mouth breathing resulted in a higher F(IO2) compared with closed-mouth breathing when 5 L/min oxygen was delivered via a pharyngeal cannula. The breathing pattern did not affect the F(IO2) in this study.

Evaluation of an oxygen mask-based capnometry device in subjects extubated after abdominal surgery

BACKGROUND

For early detection of respiratory and hemodynamic changes during anesthesia, continuous end-tidal carbon dioxide concentration (PETCO2) is monitored by capnometry. However, the accuracy of CO2 monitoring during spontaneous breathing in extubated patients remains undetermined. Therefore, we aimed to compare P(ETCO2) measured by capnometry using an oxygen mask with a carbon dioxide sampling port (capnometry-type oxygen mask) and P(CO2) in extubated subjects who had undergone abdominal surgery. Furthermore, we investigated whether spontaneous deep breathing affected dissociation between P(aCO2) and P(ETCO2).

METHODS

Adult post-abdominal surgery subjects admitted to the ICU were enrolled in this study. After extubation, oxygen was supplied at 6 L/min using the capnometry-type oxygen mask. After 30 min of oxygen supply, P(aCO2) blood gas analysis was performed, and P(ETCO2) was measured under resting and deep-breathing conditions. For both resting and deep-breathing conditions, the correlation between P(aCO2) and P(ETCO2) was analyzed. Furthermore, bias, precision, and limits of agreement were calculated using the Bland-Altman method.

RESULTS

Twenty-five subjects (15 men, 10 women) with a mean age of 62 y (interquartile range of 57-76 y) and body mass index of 20-24 kg/m(2) were studied. The correlation (r) between P(aCO2) and P(ETCO2) under resting and deep-breathing conditions was 0.50 and 0.56, respectively. Compared with P(aCO2), the bias and limits of agreement were -12.6 (-20.6 to -4.6) for resting P(ETCO2) and -9.1 (-16.0 to -2.1) for deep-breathing P(ETCO2). The association between P(aCO2) and deep-breathing P(ETCO2) was significantly smaller compared with resting P(ETCO2) (P = .002).

CONCLUSIONS

It is possible to measure the P(ETCO2) under varying breathing conditions with the capnometry-type oxygen mask in subjects receiving oxygen supplementation after extubation following upper abdominal surgery to determine whether they are properly ventilating. (ClinicalTrials.gov registration UMIN000011925.).

An antibody-free microfluidic paper-based analytical device for the determination of tear fluid lactoferrin by fluorescence sensitization of Tb3+

An inkjet-printed microfluidic paper-based analytical device (μPAD) for the detection of lactoferrin has been developed. The analyte concentration dependent fluorescence emission, caused by the sensitization of pre-deposited terbium (Tb(3+)) upon complexation with lactoferrin on the paper device, is captured using a digital camera. The dynamic response range (0.5-3 mg mL(-1)) and the limit of detection (0.30 mg mL(-1)) of the μPAD are suitable for the analysis of normal human tears and the detection of eye disorders. Finally, lactoferrin concentrations in human tear samples were analyzed by the μPADs and the assay results corresponded within 6% error to those obtained by an immunoassay (ELISA). The μPADs provide a simple, rapid and accurate method for lactoferrin detection in tear fluid. Results are obtained within 15 min of a single application of 2.5 μL of sample. To the best of our knowledge, this is the first report of a device for lactoferrin quantification relying neither on an immunoassay nor on high cost analytical instrumentation.

TWEAK/Fn14 pathway promotes a T helper 2-type chronic colitis with fibrosis in mice

Tumor necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK), a TNF superfamily member, induces damage of the epithelial cells (ECs) and production of inflammatory mediaters through its receptor Fn14 in a model of acute colitis. In our current study of chronic colitis induced by repeated rectal injection of a hapten, we found that inflammation, fibrosis, and T helper 2 (Th2)-type immunity were significantly reduced in Fn14 gene knockout (KO) mice when compared with wild-type (WT) control mice. Expression of thymic stromal lymphopoietin (TSLP) was lower in Fn14 KO colon ECs than in WT ECs. TWEAK potentiates the induction of TSLP by interleukin-13 (IL-13) in colon explants from WT but not in Fn14 KO tissue. TSLP receptor KO mice exhibit milder chronic colitis, similar to that in Fn14 KO mice. TWEAK and IL-13 synergistically promote fibroblast proliferation. Thus we propose an IL-13-TWEAK/Fn14-TSLP axis as a key mechanism underlying chronic colitis with fibrosis.

IL28B polymorphism may guide pegylated interferon plus ribavirin therapy even after curative treatment for hepatitis C virus-related hepatocellular carcinoma

The present study was designed to determine the predictive factors for the viral response to pegylated interferon-alpha plus ribavirin combination therapy (PEGIFN/RBV) administered after curative treatment for hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC). The study group was 78 patients treated between January 2005 and January 2009. The sustained viral response (SVR) rate was 25.8% (15/58) in patients infected with HCV-genotype 1 and 55.0% (11/20) in those with genotype 2. Among the 78 patients, 32 (41.0%) could not complete the treatment protocol, and this was because of HCC recurrence in 17 (53%) of them. Multivariate analysis identified partial early viral response (pEVR) as the only independent determinant of SVR [odds ratio (OR) 14.73, P = 0.013] for patients with genotype 1. Multivariate analysis identified male gender (OR 8.72, P = 0.001) and interleukin-28B (IL-28B) genotype (rs8099917) TT (OR 7.93, P = 0.007) as independent predictors of pEVR. Multivariate analysis also identified IL-28B genotype GG+TG (OR 14.1, P = 0.021) and α-fetoprotein >30 (OR 5.4, P = 0.031) as independent predictors of null response. Patients with SVR showed a better survival rate than those without SVR (P = 0.034). The second HCC recurrence rate tended to be lower in patients with SVR than in those without SVR (P = 0.054). With regard to the prognosis of patients with SVR, it is desirable to achieve SVR with interferon therapy even when administered after HCC treatment. IL-28B genotype is a potentially useful marker for the response to PEGIFN/RBV therapy administered after curative treatment of HCV-related HCC.

Atomic-level observation of disclination dipoles in mechanically milled, nanocrystalline Fe

Plastic deformation of materials occurs by the motion of defects known as dislocations and disclinations. High-resolution transmission electron microscopy was used to directly reveal the individual dislocations that constitute partial disclination dipoles in nanocrystalline, body-centered cubic iron that had undergone severe plastic deformation by mechanical milling. The mechanisms by which the formation and migration of such partial disclination dipoles during deformation allow crystalline solids to fragment and rotate at the nanometer level are described. Such rearrangements are important basic phenomena that occur during material deformation, and hence, they may be critical in the formation of nanocrystalline metals by mechanical milling and other deformation processes.

Identification and characterization of a transcriptional regulator for the lck proximal promoter

The lck gene encodes a protein-tyrosine kinase that plays a key role in signaling mediated through T cell receptor (TCR) and pre-TCR complexes. Transcription of the lck gene is regulated by two independent promoter elements: the proximal and distal promoters. Previous studies employing transgenic mice demonstrated that the sequence between -584 and -240 from the transcription start site in the mouse lck proximal promoter is required for its tissue-specific expression in the thymus. In this study, we demonstrate that a Krüppel-like zinc finger protein, mtbeta (BFCOL1, BERF-1, ZBP-89, ZNF148), previously cloned as a protein that binds to the CD3delta gene enhancer, binds to the -365 to -328 region of the lck proximal promoter. mtbeta is ubiquitously expressed in various cell lines and mouse tissues. Overexpressed mtbeta is more active in T-lineage cells than B-lineage cells for transactivating an artificial promoter consisting of the mtbeta binding site and a TATA box. Activity of the lck proximal promoter was significantly impaired by mutating the mtbeta binding site or by reducing mtbeta protein expression level by using antisense mRNA. Our results indicate that mtbeta activity is regulated in a tissue-specific manner and that mtbeta is a critical transactivator for the lck proximal promoter.

Bruton's tyrosine kinase is required for signaling the CD79b-mediated pro-B to pre-B cell transition

Formation of the pre-BCR complex is a critical check point during B cell development and induces the transition of pro-B to pre-B cells. CD79b (Igbeta) is a signaling component in the pre-BCR complex, since differentiation to the pre-B phenotype is induced by cross-linking the CD79b expressed on developmentally arrested pro-B cells from recombination-activating gene (RAG)-2-deficient mice. Bruton's tyrosine kinase (BTK) plays important roles in B cell development. However, its molecular mechanisms in early B cell development are not fully understood. To examine whether BTK functions in CD79b-mediated signaling for the pro-B/pre-B transition, we utilized RAG2/BTK double-knockout (DKO) mice. Pro-B cells from RAG2/BTK-DKO mice did not differentiate into pre-B cells following CD79b cross-linking, although tyrosine phosphorylation of cellular proteins including Erk1/2 and phospholipase C-gamma2 was induced in the same manner as RAG2-KO mice. BTK is phosphorylated after cross-linking of CD79b on RAG2-deficient pro-B cells. These findings suggest that BTK-dependent pathways downstream of CD79b are critical for the pro-B/pre-B transition and BTK-independent signaling pathways are also activated via the pre-BCR complex.

Functional dissection of the cytoplasmic subregions of the interleukin-5 receptor alpha chain in growth and immunoglobulin G1 switch recombination of B cells

The interleukin-5 receptor alpha chain (IL-5Ralpha) is known to regulate the development and function of B cells and eosinophils. Although the functions of IL-5Ralpha cytoplasmic domain subregions have been studied extensively using cultured cell lines, this approach has limitations when studying the functions of distinct primary B-cell subpopulations and their responsiveness to IL-5. In the present study, we generated mice on an IL-5Ralpha null background, each expressing a mutant form of an IL-5Ralpha transgene ligated to a mu enhancer and VH promoter, either lacking the cytoplasmic DC3 region or substituting two proline residues for alanine (ApvA) in the membrane-proximal ppvp motif of the cytoplasmic domain. The ppvp motif, which mediates activation of JAK2/STAT5 and Btk, also contributes to c-fos, c-jun and c-myc expression. IL-5Ralpha null mutant mice showed impaired B-1-cell development, reduced serum immunoglobulin G3 (IgG3) and IgM, no IL-5-induced enhancement of B-cell proliferation and IL-5-induced switch recombination from the mu gene to gamma1 gene; these were not recovered following the expression of the ApvA mutant. In contrast, absence of the DC3 region affected the IL-5-induced switch recombination from the mu to the gamma1 gene and B-1-cell development, while IL-5-induced proliferation and IgM production were at levels similar to those of B cells expressing wild-type IL-5Ralpha transgene. The results clearly indicated that the ppvp motif and the DC3 region of IL-5Ralpha played distinct roles in B-cell proliferation and differentiation. Thus, this present approach offers new insights into the functions of the cytoplasmic subregions of IL-5Ralpha, in particular its carboxy-terminal region.

MR arteriography using an implantable port system: a new method in assessing perfusion abnormalities during hepatic arterial infusion chemotherapy

We present a case in which MR arteriography (MRA) with an indwelling catheter was used in a perfusion study of intrahepatic arterial chemotherapy for liver metastases. After embolization of collateral vessels using platinum coils, CT imaging was disturbed by strong artifact. However, platinum coils produced no MR artifact. In addition, MRA had greater advantages in depicting perfusion defects than perfusion scintigraphy. We consider MRA useful in assessing perfusion abnormalities during intrahepatic arterial chemotherapy.

Molecular cloning of the mouse APS as a member of the Lnk family adaptor proteins

Engagement of cell-surface receptors leads to activation of protein tyrosine kinases, which in turn phosphorylate various downstream enzymes and adaptor proteins. Lnk is an adaptor protein that appears to be involved in signal transduction in lymphocytes, and forms an adaptor protein family with SH2-B. We tried to identify another member of the adaptor protein family and isolated the mouse APS (adaptor molecule containing PH and SH2 domains). APS contains a proline-rich region, PH and SH2 domains, and a putative tyrosine phosphorylation site at the C-terminal, and the overall structure resembles those of Lnk and SH2-B. APS is expressed in brain, kidney, muscle, and mature B cells in spleen. Mouse APS gene consists of 8 coding exons and is deduced to map to chromosome 5. APS is tyrosine phosphorylated at the C-terminal phosphorylation site conserved among the Lnk family adaptor proteins by stimulation of IL-5 or IL-3 as well as by crosslinking of B cell receptor complex. These results suggest that APS is a member of the Lnk family adaptor protein and likely plays a role in signaling in B cells.

Strategy for finding new materials for ESR dosimeters

The right strategy for finding a new ESR dosimetric material sensitive to radiation is to follow the orthodox procedures used in the development of thermoluminescence dosimeters (TLD) and phosphorescence studies. Modern procedures used in materials sciences, such as computer calculation of molecular orbitals (MO), should be employed to estimate the ESR and optical properties of prospective materials. Radiation effects in lithium and magnesium sulfates and metal salts of organic acids, such as lithium and magnesium lactates, have been investigated in search for tissue-equivalent dosimeter with a large G value.