Multiple episodes of ice loss from the Wilkes Subglacial Basin during the Last Interglacial

The Last Interglacial (LIG: 130,000-115,000 years ago) was a period of warmer global mean temperatures and higher and more variable sea levels than the Holocene (11,700-0 years ago). Therefore, a better understanding of Antarctic ice-sheet dynamics during this interval would provide valuable insights for projecting sea-level change in future warming scenarios. Here we present a high-resolution record constraining ice-sheet changes in the Wilkes Subglacial Basin (WSB) of East Antarctica during the LIG, based on analysis of sediment provenance and an ice melt proxy in a marine sediment core retrieved from the Wilkes Land margin. Our sedimentary records, together with existing ice-core records, reveal dynamic fluctuations of the ice sheet in the WSB, with thinning, melting, and potentially retreat leading to ice loss during both early and late stages of the LIG. We suggest that such changes along the East Antarctic Ice Sheet margin may have contributed to fluctuating global sea levels during the LIG.

The influence of anastomotic techniques on postoperative anastomotic complications: Results of the Oesophago-Gastric Anastomosis Audit

BACKGROUND

The optimal anastomotic techniques in esophagectomy to minimize rates of anastomotic leakage and conduit necrosis are not known. The aim of this study was to assess whether the anastomotic technique was associated with anastomotic failure after esophagectomy in the international Oesophago-Gastric Anastomosis Audit cohort.

METHODS

This prospective observational multicenter cohort study included patients undergoing esophagectomy for esophageal cancer over 9 months during 2018. The primary exposure was the anastomotic technique, classified as handsewn, linear stapled, or circular stapled. The primary outcome was anastomotic failure, namely a composite of anastomotic leakage and conduit necrosis, as defined by the Esophageal Complications Consensus Group. Multivariable logistic regression modeling was used to identify the association between anastomotic techniques and anastomotic failure, after adjustment for confounders.

RESULTS

Of the 2238 esophagectomies, the anastomosis was handsewn in 27.1%, linear stapled in 21.0%, and circular stapled in 51.9%. Anastomotic techniques differed significantly by the anastomosis sites (P < .001), with the majority of neck anastomoses being handsewn (69.9%), whereas most chest anastomoses were stapled (66.3% circular stapled and 19.3% linear stapled). Rates of anastomotic failure differed significantly among the anastomotic techniques (P < .001), from 19.3% in handsewn anastomoses, to 14.0% in linear stapled anastomoses, and 12.1% in circular stapled anastomoses. This effect remained significant after adjustment for confounding factors on multivariable analysis, with an odds ratio of 0.63 (95% CI, 0.46-0.86; P = .004) for circular stapled versus handsewn anastomosis. However, subgroup analysis by anastomosis site suggested that this effect was predominantly present in neck anastomoses, with anastomotic failure rates of 23.2% versus 14.6% versus 5.9% for handsewn versus linear stapled anastomoses versus circular stapled neck anastomoses, compared with 13.7% versus 13.8% versus 12.2% for chest anastomoses.

CONCLUSIONS

Handsewn anastomoses appear to be independently associated with higher rates of anastomotic failure compared with stapled anastomoses. However, this effect seems to be largely confined to neck anastomoses, with minimal differences between techniques observed for chest anastomoses. Further research into standardization of anastomotic approach and techniques may further improve outcomes.

Textbook outcome following oesophagectomy for cancer: international cohort study

Background

Textbook outcome has been proposed as a tool for the assessment of oncological surgical care. However, an international assessment in patients undergoing oesophagectomy for oesophageal cancer has not been reported. This study aimed to assess textbook outcome in an international setting.

Methods

Patients undergoing curative resection for oesophageal cancer were identified from the international Oesophagogastric Anastomosis Audit (OGAA) from April 2018 to December 2018. Textbook outcome was defined as the percentage of patients who underwent a complete tumour resection with at least 15 lymph nodes in the resected specimen and an uneventful postoperative course, without hospital readmission. A multivariable binary logistic regression model was used to identify factors independently associated with textbook outcome, and results are presented as odds ratio (OR) and 95 per cent confidence intervals (95 per cent c.i.).

Results

Of 2159 patients with oesophageal cancer, 39.7 per cent achieved a textbook outcome. The outcome parameter ‘no major postoperative complication’ had the greatest negative impact on a textbook outcome for patients with oesophageal cancer, compared to other textbook outcome parameters. Multivariable analysis identified male gender and increasing Charlson comorbidity index with a significantly lower likelihood of textbook outcome. Presence of 24-hour on-call rota for oesophageal surgeons (OR 2.05, 95 per cent c.i. 1.30 to 3.22; P = 0.002) and radiology (OR 1.54, 95 per cent c.i. 1.05 to 2.24; P = 0.027), total minimally invasive oesophagectomies (OR 1.63, 95 per cent c.i. 1.27 to 2.08; P &lt; 0.001), and chest anastomosis above azygous (OR 2.17, 95 per cent c.i. 1.58 to 2.98; P &lt; 0.001) were independently associated with a significantly increased likelihood of textbook outcome.

Conclusion

Textbook outcome is achieved in less than 40 per cent of patients having oesophagectomy for cancer. Improvements in centralization, hospital resources, access to minimal access surgery, and adoption of newer techniques for improving lymph node yield could improve textbook outcome.

Textbook outcome following oesophagectomy for cancer: international cohort study

BACKGROUND

Textbook outcome has been proposed as a tool for the assessment of oncological surgical care. However, an international assessment in patients undergoing oesophagectomy for oesophageal cancer has not been reported. This study aimed to assess textbook outcome in an international setting.

METHODS

Patients undergoing curative resection for oesophageal cancer were identified from the international Oesophagogastric Anastomosis Audit (OGAA) from April 2018 to December 2018. Textbook outcome was defined as the percentage of patients who underwent a complete tumour resection with at least 15 lymph nodes in the resected specimen and an uneventful postoperative course, without hospital readmission. A multivariable binary logistic regression model was used to identify factors independently associated with textbook outcome, and results are presented as odds ratio (OR) and 95 per cent confidence intervals (95 per cent c.i.).

RESULTS

Of 2159 patients with oesophageal cancer, 39.7 per cent achieved a textbook outcome. The outcome parameter 'no major postoperative complication' had the greatest negative impact on a textbook outcome for patients with oesophageal cancer, compared to other textbook outcome parameters. Multivariable analysis identified male gender and increasing Charlson comorbidity index with a significantly lower likelihood of textbook outcome. Presence of 24-hour on-call rota for oesophageal surgeons (OR 2.05, 95 per cent c.i. 1.30 to 3.22; P = 0.002) and radiology (OR 1.54, 95 per cent c.i. 1.05 to 2.24; P = 0.027), total minimally invasive oesophagectomies (OR 1.63, 95 per cent c.i. 1.27 to 2.08; P < 0.001), and chest anastomosis above azygous (OR 2.17, 95 per cent c.i. 1.58 to 2.98; P < 0.001) were independently associated with a significantly increased likelihood of textbook outcome.

CONCLUSION

Textbook outcome is achieved in less than 40 per cent of patients having oesophagectomy for cancer. Improvements in centralization, hospital resources, access to minimal access surgery, and adoption of newer techniques for improving lymph node yield could improve textbook outcome.

Postoperative outcomes in oesophagectomy with trainee involvement

BACKGROUND

The complexity of oesophageal surgery and the significant risk of morbidity necessitates that oesophagectomy is predominantly performed by a consultant surgeon, or a senior trainee under their supervision. The aim of this study was to determine the impact of trainee involvement in oesophagectomy on postoperative outcomes in an international multicentre setting.

METHODS

Data from the multicentre Oesophago-Gastric Anastomosis Study Group (OGAA) cohort study were analysed, which comprised prospectively collected data from patients undergoing oesophagectomy for oesophageal cancer between April 2018 and December 2018. Procedures were grouped by the level of trainee involvement, and univariable and multivariable analyses were performed to compare patient outcomes across groups.

RESULTS

Of 2232 oesophagectomies from 137 centres in 41 countries, trainees were involved in 29.1 per cent of them (n = 650), performing only the abdominal phase in 230, only the chest and/or neck phases in 130, and all phases in 315 procedures. For procedures with a chest anastomosis, those with trainee involvement had similar 90-day mortality, complication and reoperation rates to consultant-performed oesophagectomies (P = 0.451, P = 0.318, and P = 0.382, respectively), while anastomotic leak rates were significantly lower in the trainee groups (P = 0.030). Procedures with a neck anastomosis had equivalent complication, anastomotic leak, and reoperation rates (P = 0.150, P = 0.430, and P = 0.632, respectively) in trainee-involved versus consultant-performed oesophagectomies, with significantly lower 90-day mortality in the trainee groups (P = 0.005).

CONCLUSION

Trainee involvement was not found to be associated with significantly inferior postoperative outcomes for selected patients undergoing oesophagectomy. The results support continued supervised trainee involvement in oesophageal cancer surgery.

Mortality from esophagectomy for esophageal cancer across low, middle, and high-income countries: An international cohort study

BACKGROUND

No evidence currently exists characterising global outcomes following major cancer surgery, including esophageal cancer. Therefore, this study aimed to characterise impact of high income countries (HIC) versus low and middle income countries (LMIC) on the outcomes following esophagectomy for esophageal cancer.

METHOD

This international multi-center prospective study across 137 hospitals in 41 countries included patients who underwent an esophagectomy for esophageal cancer, with 90-day follow-up. The main explanatory variable was country income, defined according to the World Bank Data classification. The primary outcome was 90-day postoperative mortality, and secondary outcomes were composite leaks (anastomotic leak or conduit necrosis) and major complications (Clavien-Dindo Grade III - V). Multivariable generalized estimating equation models were used to produce adjusted odds ratios (ORs) and 95% confidence intervals (CI95%).

RESULTS

Between April 2018 to December 2018, 2247 patients were included. Patients from HIC were more significantly older, with higher ASA grade, and more advanced tumors. Patients from LMIC had almost three-fold increase in 90-day mortality, compared to HIC (9.4% vs 3.7%, p < 0.001). On adjusted analysis, LMIC were independently associated with higher 90-day mortality (OR: 2.31, CI95%: 1.17-4.55, p = 0.015). However, LMIC were not independently associated with higher rates of anastomotic leaks (OR: 1.06, CI95%: 0.57-1.99, p = 0.9) or major complications (OR: 0.85, CI95%: 0.54-1.32, p = 0.5), compared to HIC.

CONCLUSION

Resections in LMIC were independently associated with higher 90-day postoperative mortality, likely reflecting a failure to rescue of these patients following esophagectomy, despite similar composite anastomotic leaks and major complication rates to HIC. These findings warrant further research, to identify potential issues and solutions to improve global outcomes following esophagectomy for cancer.

Comparison of short-term outcomes from the International Oesophago-Gastric Anastomosis Audit (OGAA), the Esophagectomy Complications Consensus Group (ECCG), and the Dutch Upper Gastrointestinal Cancer Audit (DUCA)

BACKGROUND

The Esophagectomy Complications Consensus Group (ECCG) and the Dutch Upper Gastrointestinal Cancer Audit (DUCA) have set standards in reporting outcomes after oesophagectomy. Reporting outcomes from selected high-volume centres or centralized national cancer programmes may not, however, be reflective of the true global prevalence of complications. This study aimed to compare complication rates after oesophagectomy from these existing sources with those of an unselected international cohort from the Oesophago-Gastric Anastomosis Audit (OGAA).

METHODS

The OGAA was a prospective multicentre cohort study coordinated by the West Midlands Research Collaborative, and included patients undergoing oesophagectomy for oesophageal cancer between April and December 2018, with 90 days of follow-up.

RESULTS

The OGAA study included 2247 oesophagectomies across 137 hospitals in 41 countries. Comparisons with the ECCG and DUCA found differences in baseline demographics between the three cohorts, including age, ASA grade, and rates of chronic pulmonary disease. The OGAA had the lowest rates of neoadjuvant treatment (OGAA 75.1 per cent, ECCG 78.9 per cent, DUCA 93.5 per cent; P < 0.001). DUCA exhibited the highest rates of minimally invasive surgery (OGAA 57.2 per cent, ECCG 47.9 per cent, DUCA 85.8 per cent; P < 0.001). Overall complication rates were similar in the three cohorts (OGAA 63.6 per cent, ECCG 59.0 per cent, DUCA 62.2 per cent), with no statistically significant difference in Clavien-Dindo grades (P = 0.752). However, a significant difference in 30-day mortality was observed, with DUCA reporting the lowest rate (OGAA 3.2 per cent, ECCG 2.4 per cent, DUCA 1.7 per cent; P = 0.013).

CONCLUSION

Despite differences in rates of co-morbidities, oncological treatment strategies, and access to minimal-access surgery, overall complication rates were similar in the three cohorts.

Minimally invasive oesophagectomy with extended lymph node dissection and thoracic duct resection for early-stage oesophageal squamous cell carcinoma

BACKGROUND

Oesophageal squamous cell carcinoma is an aggressive disease owing to early and widespread lymph node metastases. Multimodal therapy and radical surgery may improve prognosis. Few studies have investigated the efficacy of radical lymph node and thoracic duct resection.

METHODS

Patients with oesophageal squamous cell carcinoma who underwent transthoracic minimally invasive oesophagectomy (TMIE) for cancer at Keio University Hospital between January 2004 and December 2016 were selected. Between 2004 and 2008, TMIE was performed in the lateral decubitus position without thoracic duct resection (standard TMIE). From 2009 onwards, TMIE with extended lymph node and thoracic duct resection was introduced (extended TMIE). Demographics, co-morbidity, number of retrieved lymph nodes, pathology, postoperative complications and recurrence-free survival (RFS) were compared between groups.

RESULTS

Forty-four patients underwent standard TMIE and 191 extended TMIE. There were no significant differences in clinical and pathological tumour stage or postoperative complications. The extended-TMIE group had more lymph nodes removed at nodal stations 106recL and 112. Among patients with cT1 N0 disease, RFS was better in the extended-TMIE group (P < 0·001), whereas there was no difference in RFS between groups in patients with advanced disease.

CONCLUSION

Extended TMIE including thoracic duct resection increased the number of lymph nodes retrieved and was associated with improved survival in patients with cT1 N0 oesophageal squamous cell carcinoma.

Estimation of Evolutionary Rates of Mitochondrial DNA in Two Japanese Wood Mouse Species Based on Calibrations with Quaternary Environmental Changes

Reliable estimates of evolutionary rates of mitochondrial DNA might allow us to build realistic evolutionary scenarios covering broad time scales based on phylogenetic inferences. In the present study, we sought to obtain estimates of evolutionary rates in murine rodents using calibrations against historical biogeographic events. We first assumed that land-bridge-like structures that appeared intermittently at glacial maxima with 100,000-year intervals shaped the divergence patterns of cytochrome b (Cytb) sequences (1140 bp) of the larger Japanese wood mouse Apodemus speciosus. The comparison of sequences from peripheral remote islands that are separated from one another by deep straits allowed us to estimate mitochondrial DNA evolutionary rates (substitutions/site/million years) to be 0.027 to 0.036, with presumed calibrations from 140,000, 250,000, 350,000, and 440,000 years ago. Second, we addressed rapid expansion events inferred from analyses of the Cytb sequences of the lesser Japanese wood mouse A. argenteus. We detected five expansion signals in the dataset and established three categories based on the expansion parameter tau values: 3.9, 5.6-5.7, and 7.8-8.1. Considering that the climate became warmer 15,000, 53,000, and 115,000 years ago after preceding periods of rapid cooling, we calculated evolutionary rates to be 0.114, 0.047, and 0.031, respectively. This preliminary concept of the evolutionary rates on a time scale from 15,000 to 440,000 years ago for the wood mouse should be refined and tested in other species of murine rodents, including mice and rats.

Sources of atmospheric black carbon and related carbonaceous components at Rishiri Island, Japan: The roles of Siberian wildfires and of crop residue burning in China

A field study was conducted to clarify sources of atmospheric black carbon and related carbonaceous components at Rishiri Island, Japan. We quantified equivalent black carbon (eBC) particle mass and the absorption Ångström exponent (AAE), atmospheric CO and CH₄, in addition to levoglucosan in total suspended particles, a typical tracer of biomass burning. Sixteen high eBC events were identified attributable to either anthropogenic sources or biomass burning in Siberia/China. These events were often accompanied by increases of co-emitted gases such as CH₄ and CO. Specifically, we observed pollution events with elevated eBC, AAE, levoglucosan, and CH₄CO slope in late July 2014, which were attributed to forest fires in Siberia by reference to the FLEXPART model footprint and fire hotspots. In autumn, drastic increases of eBC, AAE, and levoglucosan were observed, accompanied by an eBC-CO slope of >15 ng m^-3/ppb, resulting from long-range transport of emissions from extensive burning of crop residue on the Northeast China Plain. Other than the sources of fossil fuel combustion in China and forest fires in Siberia, we report for the first time that pollution events in northern Japan are caused by crop residue burning in China. This study elucidated valuable information that will improve understanding of the effects of biomass burning in East Asia on atmospheric carbonaceous components.

Long-term functional outcomes after replacement of the esophagus with gastric, colonic, or jejunal conduits: a systematic literature review

It is generally recognized that in patients with an intact stomach diagnosed with esophageal cancer, gastric tubulization and pull-up shall always be the preferred technique for reconstruction after an esophageal resection. However, in cases with extensive gastroesophageal junction (GEJ) cancer with aboral spread and after previous gastric surgery, alternative methods for reconstruction have to be pursued. Moreover, in benign cases as well as in those with early neoplastic lesions of the esophagus and the GEJ that are associated with long survival, it is basically unclear which conduit should be recommended. The aim of this study is to determine the long-term functional outcomes of different conduits used for esophageal replacement, based on a comprehensive literature review. Eligible were all clinical studies reporting outcomes after esophagectomy, which contained information on at least three years of follow-up after the operation in patients who were older than 18 years of age at the time of the operation. The review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A systematic web-based search using MEDLINE, the Cochrane Library, and EMBASE databases was performed, reviewing medical literature published between January 2006 and December 2015. The scientific quality of the data was generally low, which allowed us to incorporate only 16 full text articles for the final analyses. After a gastric pull-up, the proportion of patients who suffered from dysphagia varied substantially but seemed to decrease over time with a mild dysphagia remaining during long-term follow-up. When reflux-related symptoms and complications were addressed, roughly two third of patients experienced mild to moderate reflux symptoms a long time after the resection. Following an isoperistaltic colonic graft, the functional long-term outcomes regarding swallowing difficulties were sparsely reported, while three studies reported reflux/regurgitation symptoms in the range of 5% to 16%, one of which reported the symptom severity as being mild. Only one report was available after the use of a long jejunal segment, which contained only six patients, who scored the severity of dysphagia and reflux as mild. Very few if any data were available on a structured assessment of dumping and disturbed bowel functions. Few high-quality data are available on the long-term functional outcomes after esophageal replacement irrespective of the use of a gastric tube, the right or left colon or a long jejunal segment. No firm conclusions regarding the advantages of one graft over the other can presently be drawn.

Outcomes following the main treatment options in patients with a leaking esophagus: a systematic literature review

Leakage from the esophagus and gastroesophageal junction can be lethal due to uncontrolled contamination of the mediastinum. The most predominant risk factors for the subsequent clinical outcome are the patients' delay as well as the delay of diagnosis. Two major therapeutic concepts have been advocated: either prompt closure of the leakage by insertion of a self-expandable metal stent (SEMS) or more traditionally, surgical exploration. The objective of this review is to carefully scrutinize the recent literature and assess the outcomes of these two therapeutic alternatives in the management of iatrogenic perforation-spontaneous esophageal rupture as separated from those with anastomotic leak. A systematic web-based search using PubMed and the Cochrane Library was performed, reviewing literature published between January 2005 and December 2015. Eligible studies included all studies that presented data on the outcome of SEMS or surgical exploration in case of esophageal leak (including >3 patients). Only patients older than 15 years of age by the time of admission were included. Articles in other languages but English were excluded. Treatment failure was defined as a need for change in therapeutic strategy due to uncontrolled sepsis and mediastinitis, which usually meant rescue esophagectomy with end esophagostomy, death occurring as a consequence of the leakage or development of an esophagorespiratory fistula and/or other serious life threatening complications. Accordingly, the corresponding success rate is composed of cases where none of the failures above occurred. Regarding SEMS treatment, 201 articles were found, of which 48 were deemed relevant and of these, 17 articles were further analyzed. As for surgical management, 785 articles were retrieved, of which 82 were considered relevant, and 17 were included in the final analysis. It was not possible to specifically extract detailed clinical outcomes in sufficient numbers, when we tried to separately analyze the data in relation to the cause of the leakage: i.e. iatrogenic perforation-spontaneous esophageal rupture and anastomotic leak. As for SEMS treatment, originally 154 reports focused on iatrogenic perforation, 116 focused on spontaneous ruptures, and only four described the outcome following trauma and foreign body management. Only five studies used a prospective protocol to assess treatment efficacy. Regarding a leaking anastomosis, 80 reports contained information about the outcome after treatment of esophagogastrostomies and 35 reported the clinical course after an esophagojejunostomy. An overall success rate of 88% was reported among the 371 SEMS-treated patients, where adequate data were available, with a reported in hospital mortality amounting to 7.5%. Regarding the surgical exploration strategy, the vast majority of patients had an attempt to repair the defect by direct or enforced suturing. This surgical approach also included procedures such as patching with pleura or with a diaphragmatic flap. The overall reported success rate was 83% (305/368) and the in-hospital mortality was 17% (61/368). The current literature suggests that a SEMS-based therapy can be successfully applied as an alternative therapeutic strategy in esophageal perforation rupture.

Phylogenetic diversity and distribution of bacterial and archaeal amoA genes in the East China Sea during spring

Microbial nitrification is a key process in the nitrogen cycle in the continental shelf ecosystems. The genotype compositions and abundance of the ammonia monooxygenase gene, amoA, derived from ammonia-oxidizing archaea (AOA) and bacteria (AOB) in two size fractions (2-10 and 0.2-2 µm), were investigated in the East China Sea (ECS) in May 2008 using PCR-denaturing gradient gel electrophoresis (DGGE) and quantitative PCR (qPCR). Four sites were selected across the continental shelf edge: continental shelf water (CSW), Kuroshio branch water (KBW), transition between CSW and KBW (TCSKB) and coastal KBW (CKBW). The gene copy numbers of AOA-amoA were higher than those of AOB-amoA in ECS. The relative abundance of amoA to the total 16S rRNA gene level reached approximately 15% in KBW and CKBW for the free-living fraction of AOA, whereas the level was less than 0.01% throughout ECS for the AOB. A cluster analysis of the AOA-amoA-DGGE band pattern showed distinct genotype compositions in CSW in both the size fractions and in the surface of the TCSKB and KBW. Sequences of the DGGE bands were assigned to two clades. One of the clades exclusively consisted of sequences derived from the 2-10-µm fraction. This study revealed that AOA-amoA abundance dominated over AOB-amoA throughout the ECS, whereas the genotype composition of AOA-amoA were distributed heterogeneously across the water masses. Additionally, this is the first report showing the distribution of AOA-amoA genotypes characteristic to particle-associated AOA in the offshore of the East China Sea.

Circulating tumor cells detected in patients with gastrointestinal cancers associate with tumor stage and response to chemotherapy

4635

Background: Circulating tumor cells (CTCs) in metastatic breast cancer has been reported to correlate with shorter overall survival. The purpose of this study was to clarify the clinical significance of CTCs in gastrointestinal cancers. Methods: CTCs of 108 patients with stage III or IV gastrointestinal cancers and 38 healthy volunteers were measured by use of the CellSearch system. Correlation between CTC counts and clinicopathologic variables was examined. Results: The number of CTCs in stage IV patients (23.0 ± 109.1) was significantly larger than that in healthy donors (0.1 ± 0.2) and that in stage III patients (0.4 ± 1.8) (p < 0.001). =2 CTCs were more frequently found in stage IV patients (41.6%) than in healthy donors (0%) and in stage III patients (3.2%) (p < 0.001). =2 CTCs in gastric or colorectal cancer had significant correlation with peritoneal dissemination (p = 0.029). =2 CTCs in esophageal cancer had significant correlation with pleural dissemination (p = 0.030). In 10 of 32 CTC positive (=2) patients with stage IV gastrointestinal cancers, CTC was measured before initiation of a new line of chemotherapy and more than 3 weeks after initiation of therapy. The change in CTCs correlated with disease progression and reflected chemotherapeutic effect. Conclusions: This study suggested measurement of CTCs in gastrointestinal cancer patients shows promise as a tool for judging advanced tumor stage, predicting peritoneal or pleural dissemination and monitoring response to chemotherapy.

No significant financial relationships to disclose.

Multiscale computing

Multiscale computing (MSC) involves the computation, manipulation, and analysis of information at different resolution levels. Widespread use of MSC algorithms and the discovery of important relationships between different approaches to implementation were catalyzed, in part, by the recent interest in wavelets. We present two examples that demonstrate how MSC can help scientists understand complex data. The first is from acoustical signal processing and the second is from computer graphics.

A compressive gammachirp auditory filter for both physiological and psychophysical data

A gammachirp auditory filter was developed by Irino and Patterson [J. Acoust. Soc. Am. 101, 412-419 (1997)] to provide a level-dependent version of the linear, gammatone auditory filter, with which to explain the level-dependent changes in cochlear filtering observed in psychophysical masking experiments. In this 'analytical' gammachirp filter, the chirp varied with level and there was no explicit representation of the change in filter gain or compression with level. Subsequently, Carney et al. [J. Acoust. Soc. Am. 105, 2384-2391 (1999)] reviewed Carney and Yin's [J. Neurophysiol. 60, 1653-1677 (1988)] reverse-correlation (revcor) data and showed that the frequency glide of the chirp does not vary with level in their data. In this article, the architecture of the analytical gammachirp is reviewed with respect to cochlear physiology and a new form of gammachirp filter is described in which the magnitude response, the gain, and the compression vary with level but the chirp does not. This new 'compressive' gammachirp filter is used to fit the level-dependent revcor data reported by Carney et al. (1999) and the level-dependent masking data reported by Rosen and Baker [Hear. Res. 73, 231-243 (1994)].

Specific gel electrophoresis method detects two isoforms of human intestinal alkaline phosphatase

We have demonstrated that the 6.0% polyacrylamide disc gel electrophoresis (PAGE) method in the presence of 1% Triton X-100 clearly separated both normal molecular mass intestinal alkaline phosphatase (NIAP) and bone alkaline phosphatase (BAP) in serum regardless of the ABO blood group and the secretor status of the subjects. From the results under the usual 7.5% PAGE condition, overlapping mobilities of NIAP and BAP were found in particular in nonsecretor subjects after a high-fat meal. Under the above conditions, the apparent BAP percentage three hours after a meal was higher in nonsecretors than in subjects under fasting conditions, because NIAP activity in serum rose sharply following a high-fat meal. In contrast, under our 6.0% PAGE method, the NIAP and BAP were clearly separated from each other regardless of whether the subjects were fasting or had ingested a high-fat meal. In addition, an elevated level of the circulating NIAP can be another marker for patients with liver cirrhosis. Considering all these factors, the 6.0% PAGE method proposed by us is not only a useful method for the separation of intestinal alkaline phosphatase (IAP) isoforms, but can also be useful for the analysis of other usual AP isozymes.

Reduction of reaction differences between human mercaptalbumin and human nonmercaptalbumin measured by the bromcresol purple method

Although the bromcresol purple (BCP) method provides high specificity in measurements of serum albumin concentrations, we discovered a reaction difference between the values for human mercaptalbumin (HMA) and human nonmercaptalbumin (HNA) measured by the BCP. We found that the color intensity of HMA with BCP present in the reduced form in the albumin of fresh serum, was lower than for HNA. While maintaining specificity for albumin, we reduced the reaction difference between HMA and HNA, with the addition of sodium dodecylsulfate and 5,5'-dithiobis(2-nitrobenzoic acid) to the BCP reagent. The mean albumin concentration by the BCP procedure for 63 fresh sera and the 63 sera stored for 2 days at room temperature were 35.6 g/L and 38.1 g/L, respectively. Those by the modified BCP procedure were 39.8 g/L and 39.9 g/L, respectively. The difference in measured values between the fresh and stored sera which is believed to be caused by the conversion of HMA to HNA during the storage of sera was not observed in the case of the modified BCP procedure. Our modified BCP method is effective in eliminating uncertainty of the albumin concentration assigned to assay calibrators for the conventional BCP method.

Modeling temporal asymmetry in the auditory system

Sound sources in the environment produce waves that are almost invariably asymmetric in time, and human listeners are highly sensitive to temporal asymmetry. The spectral analysis and neural transduction processes in the cochlea enhance temporal asymmetry, as do time-domain models of cochlear processes, but it appears that the resulting asymmetry is not sufficient to explain the observed perceptual asymmetry. In the auditory image model (AIM) of hearing, the temporal asymmetry in the neural activity produced by the cochlea is further enhanced by the "strobed" temporal integration that converts the neural activity pattern into an auditory image, and the temporal asymmetry in the auditory image is sufficient to explain the perceptual asymmetry. Modern versions of the "duplex model" of pitch have time-domain cochlea simulations that produce neural activity with temporal asymmetry similar to that produced by AIM. In the final stage, however, they apply autocorrelation to the neural pattern and autocorrelation is a symmetric process in time. In this paper the effect of autocorrelation on temporal asymmetry is examined in a range of auditory models with varying forms of auditory filterbank, compression, and neural transduction. It is concluded that autocorrelation does not enhance temporal asymmetry and often reduces it, and that autocorrelogram models cannot explain the magnitude of the perceptual asymmetry in their current form. Then, the original version of strobed-temporal-integration is reviewed with regard to temporal asymmetry, and the delta-gamma theory of temporal asymmetry [Irino and Patterson, J. Acoust. Soc. Am. 99, 2316-2331 (1996)] is used to develop a new version of strobed-temporal-integration that is more robust and physiologically more plausible.

Changes in intestinal alkaline phosphatase isoforms in healthy subjects bearing the blood group secretor and non-secretor

We found the high molecular mass intestinal alkaline phosphatase (HIAP) and normal molecular mass intestinal alkaline phosphatase (NIAP) in serum at fasting and after fatty meal by use of 6.0% polyacrylamide gel electrophoresis (PAGE) in the presence of 1% Triton X-100. HIAP only appeared in serum of Lewis blood group secretors ¿Le(a-b+)¿, and HIAP levels were dependent on ABO blood groups. Among the secretors, the highest activities of HIAP in fasting serum were observed in subjects with blood groups O and B (8.6+/-1.4 U/1; mean+/-SD) and the lowest activities were associated with blood group A (0.7+/-0.2 U/1; mean+/-SD), and the HIAP activities did not change after fatty meal. In contrast, NIAP was present in the serum of both secretors and non-secretors regardless of ABO blood group. Trace amounts of NIAP remained in fasting serum; however serum NIAP activities rose sharply after fatty meal. The remaining ratios of NIAP activity at fasting and 9 h after fatty meal of secretors were approximately the same as those of non-secretors. The electrophoretic mobility on PAGE or the apparent molecular mass estimated by gel filtration of serum NIAP in secretors was slightly different from that in non-secretors. In addition, HIAP can be normalized to NIAP on PAGE in the absence of Triton X-100, and the electrophoretic mobility of normalized-NIAP was identical to that of original NIAP in secretors. Accordingly, it can be concluded that the structure of serum NIAP in the secretor was different from that in the non-secretor, because HIAP is only formed by serum NIAP in the secretor. These results suggest that differences in serum NIAP in the secretor and the non-secretor may be closely related to the appearance of IAP in the circulation.

Properties of high-molecular-mass placental alkaline phosphatases in normal pregnancy sera

We examined the appearance of high-molecular-mass placental alkaline phosphatases (HPLAPs) in the serum of normal pregnant women by means of polyacrylamide gel electrophoresis (PAGE) in the presence of Triton X-100. The HPLAPs were undetectable or only slightly detectable by PAGE in the absence of Triton X-100. The HPLAPs were detected in all sera sampled during the last trimester of pregnancy. The catalytic activities of total placental alkaline phosphatase (TPLAP) and HPLAPs were correlated (r = 0.96) and the ratio of HPLAPs/TPLAP catalytic activity was 0.20 (0.06) (mean and SD) in 40 serum samples from pregnant women. The HPLAPs appear to be formed from a common dimeric placental alkaline phosphatase (PLAP) (common-PLAP), as judged by the fact that they were formed again after removal of HPLAPs from serum by gel filtration. The formation of HPLAPs was more prominently observed with the faster fractions of gel filtration. The apparent molecular mass of the HPLAPs in pregnancy serum was 720 KDa by gel filtration. HPLAPs were not converted to common-PLAP by phosphatidylinositol-specific phospholipase (PIPL) C and PIPL-D treatments. The HPLAPs were selectively incorporated into liposomes consisting of phosphatidylcholine/cholesterol, and most of the PIPL-D-treated PLAP could from HPLAPs, while a small amount of PLAP could not form HPLAPs. On the other hand, HPLAPs in pregnant women's sera and HPLAPs prepared from partially purified PLAP in vitro could be converted to common-PLAP by brief treatment with subtilisin. However, the highly purified PLAP could not form HPLAPs in the presence of Triton X-100. These results suggest that PIPL-D-resistant and PLAP-associated serum protein may regulate the conversion of PLAP to HPLAP in the presence of Triton X-100.

Pharmacokinetics and pharmacodynamics of FK143, a nonsteroidal inhibitor of steroid 5 alpha-reductase, in healthy volunteers

The pharmacokinetics and pharmacodynamics of FK143, a new nonsteroidal inhibitor of steroid 5 alpha-reductase, were investigated in healthy volunteers, with use of plasma FK143 concentrations and serum dihydrotestosterone levels as an index for pharmacologic effects. The area under the plasma concentration-time curve from zero to infinity [AUC(0-infinity)] and maximum plasma concentration [Cmax] were increased dose proportionally after oral administration (100 to 500 mg) while subjects were in the fed state. The AUC(0-infinity) and Cmax after 500 mg oral administration during fed conditions were significantly larger than those during the fasted state, suggesting an increase of the absorption of FK143. Dihydrotestosterone concentrations after a single administration of FK143 (100 to 500 mg) during fed conditions decreased to about 65% of predose values and thereafter slowly recovered to the same levels as predose values at 168 hours. A combined pharmacokinetic-pharmacodynamic model was constructed with use of changes in dihydrotestosterone concentrations. The pharmacokinetic-pharmacodynamic profiles of FK143 after repeated administration were predictable with use of the pharmacokinetic-pharmacodynamic parameters obtained after a single administration of FK143.

[Non-specific neurological complaints and silent cerebral infarction]

To clarify the relationship between non-specific neurological complaints and silent cerebral infarction (SCI), we studied 82 patients (56 +/- 8 years old; mean +/- SD) who presented with at least one complaint (headache, dizziness, forgetfulness) and 76 normal volunteers with no complaints (55 +/- 7 years old). All subjects were evaluated with a questionnaire for complaints and with 0.5 T magnetic resonance imaging of the brain for the presence of SCI. Several risk factors for stroke were also studied. SCI was significantly more common in the patients (18%) than in the normal subjects (7%, p < 0.05). SCI was more common in subjects with dizziness (40%) and in those with headache (18%) than in those with no complaints (p < 0.01, p < 0.05, respectively). Dizziness and forgetfulness were closely associated with SCI (p < 0.05). Two risk factors for stroke, age and hypertension, correlated with SCI. These results clearly show that non-specific neurological complaints are closely related to SCI.

Temporal asymmetry in the auditory system

When a damped exponential with a half-life of 4-8 ms is repeated every 25-50 ms and used to modulate a sinusoid or a wideband noise, it suppresses the sound quality typically associated with the carrier. When the envelopes of these "damped" sounds are reversed in time, producing "ramped" sounds, a continuous component with the sound quality of the carrier is restored to the perception. This paper presents an experiment that measures the temporal asymmetry revealed by this perceptual contrast. A ramped sinusoid or noise with a given half-life was presented with a damped sinusoid or noise having the same or greater half-life, to determine the damped half-life required to produce a continuous component with the equivalent relative strength in the two sounds. The results with sinusoidal carriers show that the half-life of the damped sound has to be, on average, about five times the half-life of the ramped sound if the tonal component of the two perceptions is to have the same relative strength. The asymmetry for the noise carrier is about half that of the sinusoidal carrier and, again, the damped sound has the greater matching half-life. Several multichannel auditory models based on a gammatone filterbank are used to try to explain the data in terms of traditional leaky integration, but they produce neither sufficient asymmetry nor the correct pattern of asymmetry. A "delta-gamma" theory is then developed to provide a framework for understanding temporal asymmetry in the auditory system. The theory is used to compare the temporal asymmetry produced by several auditory models and to explain when and how they can accommodate the perceptual asymmetry observed in the experiments.

Phosphorylcholine as a unique substrate for human intestinal alkaline phosphatase

1. The enzymatic nature of human liver, bone, placental and intestinal alkaline phosphatases (ALPs) were investigated with phosphorylcholine (PC), phosphorylethanolamine, pyridoxal-5'-phosphate and p-nitrophenylphosphate at a weakly alkaline pH. 2. The apparent Km value of the intestinal ALP with PC was the highest of all ALPs tested. Intestinal ALP hydrolyzes PC the most and has higher affinity for choline as a transphosphorylating acceptor than the other ALPs. In addition, the intestinal ALP activity with PC was most susceptible to Na2HPO4, in the tested ALPs. 3. The present results suggest that PC is a unique substrate for human intestinal ALP, which may be related to the metabolism of PC or choline as part of phosphatidylcholine.

Determination of proteins by a reverse biuret method combined with the copper-bathocuproine chelate reaction

A method of protein determination has been developed which combines the biuret reaction and the copper(I)-bathocuproine chelate reaction. Protein in the specimen forms a Cu(2+)-protein chelate complex (biuret reaction) during the first step. Excess Cu2+ is reduced to Cu+ by ascrobic acid, allowing the Cu+ to form a Cu(+)-bathocuproine chelate complex during the second step. The amount of Cu(+)-bathocuproine chelate complex formed is inversely proportional to the protein concentration. The sensitivity (epsilon = 1.4 x 10(6) 1.mol-1.cm-1 against human albumin) of this method was higher than that of the original Lowry (9.8 x 10(5)), pyrogallol red (1.0 x 10(6)) and commercially available Coomassie Brilliant Blue G.250 methods (6.7 x 10(5)). The color intensities of human gamma-globulin, human globulin (fractions IV-1 and IV-4), bovine albumin, egg albumin and horse gamma-globulin against human albumin (100%) ranged from 92 to 101%. The results obtained with the present method (y) correlated well with those determined by the biuret method (r = 0.998, y = 0.98 chi - 0.002, x = 1.31, y = 1.29 g/l) in 30 diluted sera. These results confirm that this assay is similar in sensitivity to the original Lowry method, is rapid and has similar reactivity to each of the various proteins in biological fluids.

[Spontaneous cleft palate in CF#1/Ohu mice]

We found a spontaneous cleft palate in a mouse of CF#1/Ohu (Ohu University, Japan). Further, the frequency of the spontaneous cleft palate in strains of CF#1/Jms (Institute of Medical Science, University of Tokyo, Japan) and CF#1/Jah (National Institute of Animal Health, Japan) were about 3%, respectively. The frequency and the types of spontaneous cleft palate in CF#1 were clearly different from those in A/J and CL/Fr strains which were used as model animals of lip and cleft palate. We think that CF#1 is the new animal models to analyze a cleft palate genetically and biochemically.

Optimized Stoneley wave device by proper choice of glass overcoat

The characteristics of a Stoneley wave propagated along an interface between a piezoelectric material and an isotropic material were investigated both theoretically and experimentally. First, the condition for the existence of Stoneley waves was shown for various piezoelectric materials. A rule of thumb for selecting the combination of the two materials was obtained. Then, LiTaO(3) was selected as the piezoelectric material and SiO(2) was selected the isotropic material. After the calculation of the Stoneley wave characteristics, actual devices were fabricated and measured. The experimental results were found to be in good agreement with the theory; zero slope temperature and high electromechanical coupling coefficient ( K(2)=1.5%) were obtained for Stoneley wave propagation between SiO(2)/X-148 degrees LiTaO(3). As a result, future surface-acoustic-wave (SAW) devices can be made without any package.

Propagation of boundary acoustic waves along a ZnO layer between two materials

Theoretical and experimental results on boundary acoustic waves propagated along a ZnO layer sandwiched between two materials are presented. It is shown that boundary acoustic waves can exist only when the material constants of the three materials satisfy the particular conditions obtained here. Experiments on SiO(2)/ZnO/SiO(2 ) were performed to verify the theoretical prediction of the existence of boundary waves. Boundary waves were excited and received by interdigital transducers and propagated along the ZnO layer. Propagation loss was practically the same as for Rayleigh waves, indicating a proper mode of the system. The results suggest that future SAW (surface acoustic wave) devices can be made without any package.

Cardiac abnormalities in ischemic cerebrovascular disease studied by two-dimensional echocardiography

In the study of cardiac abnormalities responsible for the development of cerebral embolism two-dimensional echocardiography was performed on 350 patients with ischemic cerebrovascular disease. The results were compared with those obtained from 350 controls without any history of stroke. Atrial fibrillation was detected on ECG in 115 cases (33%) of the patients and in 35 cases (10%) of the controls (p less than 0.001). The structural cardiac diseases observed in stroke patients were: rheumatic heart disease (RHD) in 37, congestive cardiomyopathy (CCM) in 7, hypertrophic cardiomyopathy (HCM) in 19, mitral annulus calcification (MAC) in 29, mitral valve prolapse (MVP) in 9, and myocardial infarction (MyI) in 10 patients. Controls were found to have these lesions in 11, 2, 3, 12, 4 and 9 patients respectively. RHD (p less than 0.001), HCM (p less than 0.01) and MAC (p less than 0.01) were significantly more frequent in patients with ischemic cerebrovascular disease, but not MyI, CCM or MVP. Intracardiac thrombi were diagnosed in 29 cases of patients and in 4 cases of controls (p less than 0.001). Our data suggested that nonrheumatic heart diseases such as MAC and HCM could also be considered as causes of embolic stroke. The reasons for the variable frequencies of cardiac abnormalities reported in the literature for stroke patients are discussed.

Angiographical analysis of acute cerebral infarction followed by "cascade"-like deterioration of minor neurological deficits. What is progressing stroke?

In order to understand the mechanism of clinical worsening in patients with cerebral infarction, attention was focused on the changes in cerebral angiograms obtained repeatedly before and after neurological deterioration. Among 212 stroke patients with minor neurological deficits, incomplete hemiparesis progressed to complete hemiplegia in 15 patients several days after the beginning of symptoms. On admission, 3 had internal carotid artery occlusion, 2 had stenosis of the internal carotid artery, 5 had occlusion of the middle cerebral arterial trunk, 2 had occlusion of the middle cerebral arterial branch, and 3 had no angiographically visible occlusion. The changes between the first and the second angiograms were of different varieties: another recurrent occlusion, progression of occlusion, new occlusion in the cerebral arteries opacified through the collateral pathway, recanalization of the initially occluded artery, and no change. Such different patterns of pathophysiological events show that the mechanism of neurological worsening in infarcted patients is not uniform. Based on the results from the present study, several problems which arose during the investigation and the somewhat vague definition of "progressing stroke" currently in use are discussed.

Cerebellar infarction with obstructive hydrocephalus

The authors review 15 patients with acute cerebellar infarction accompanied by obstructive hydrocephalus. These patients were among 1700 consecutive patients with acute cerebrovascular disease who were examined by angiography and also, except for the initial 320 cases. by computerized tomography (CT) scan. The CT scans were helpful in diagnosis and management of the patients. It demonstrated cerebellar mass lesions as being low density, isodense, or high density, according to the amount of hemorrhage into the infarcted area. Such cerebellar mass lesions caused acute compression of the posterior fossa. The clinical picture was determined mainly by the extent of the initially infarcted area in the vertebrobasilar territory and the speed of enlargement of the subsequently developing cerebellar mass lesion. Suboccipital decompressive surgery was performed in 10 patients and was generally beneficial. The postoperative prognosis depended mainly on the presence or absence of coexisting brain-stem infarction. Five patients who were managed conservatively died during the acute stage. Prompt and correct diagnosis of this illness is required to ensure adequate therapy.

Pattern difference of reversed ophthalmic blood flow between occlusion and stenosis of the internal carotid artery. An ultrasonic Doppler study

Reversed ophthalmic blood flow in the occlusions (33 patients) and stenoses (11 patients) of the internal carotid artery (ICA) was examined using the ultrasonic Doppler technique. The Doppler shift frequencies of the blood flow signal were analyzed to obtain their sound spectrogram. In stenosis of the ICA, "presystolic notch" was more frequently observed and "d/S" value (S, d; maximum blood flow velocity at systolic and diastolic) was smaller than in occlusion. These two characteristics of stenosis distinguish it from occlusion with 89% accuracy although this method is applicable only for the patients with reversed ophthalmic blood flow.