The epidemiology of pulmonary Mycobacterium abscessus species in Japanese population

BACKGROUND

Mycobacterium abscessus species (MABS) is now a most virulent rapidly growing mycobacteria (RGM), and the rapid increase of MABS was recently observed worldwide, including in Japan. Thus, we gathered evidences of the presence of pulmonary MABS in Japanese population from Japanese articles.

METHODS

we searched studies that addressed the isolation of pulmonary non-tuberculous Mycobacteria (NTM) or MABS from clinical respiratory specimens in Japan.

RESULTS

the ratio of MABS to NTM was 3.04% (95% confidence interval [CI]: 2.51-3.68), found using the meta-analysis of single proportions. The estimated mean age of patients infected with MABS was 67.72 years (95% CI: 65.41-70.02), found using the meta-analysis of single means. The estimated proportion of females, never smoker, and the co-infection with Mycobacterium avium complex (MAC) was 66.75% (95% CI: 59.23-73.50), 67.57% (95% CI: 62.43-72.32), and 36.74% (95% CI: 25.30-49.90), respectively. The characteristics of MABS in Japan were considerably different from that in Europe and United States from the perspective of age, gender, and complications, wherein the patients in these countries tended to be younger, had lower number of females, and had more occurrences of hereditary diseases, including cystic fibrosis (CF).

CONCLUSION

we hypothesized that the characteristics of MABS in the Japanese were involved in those of non-CF MABS, and the distribution of gender and age of MABS were similar to that of MAC in the Japanese.

Impact of bleeding event for new cancer diagnosis in patients with antiplatelet therapy after percutaneous coronary intervention

BACKGROUND

Bleeding is a frequent event in coronary artery disease (CAD) patients treated with antiplatelet therapy after percutaneous coronary intervention (PCI). The impact of bleeding in CAD patients with antiplatelet therapy for cancer diagnosis remains unclear.

METHODS AND RESULTS

Consecutive 1565 CAD patients treated with antiplatelet therapy after PCI, without anticoagulation therapy, were enrolled. We aimed to investigate the relationships between bleeding events and the incidence of new cancer diagnosis. Among 1565 patients, 178 (11.3 %) experienced any bleeding events defined as Bleeding Academic Research Consortium (BARC) type 1, 2, 3, or 5 bleeding and 75 (4.7 %) experienced minor bleeding events defined as BARC 1 or 2 bleeding, and 116 (7.4 %) were diagnosed with new cancer during a mean follow-up period of 1528 days. Among 178 patients with any bleeding and 75 patients with minor bleeding events, 20 (11.2 %) and 13 (17.3 %) were subsequently diagnosed with new cancer, respectively. The proportion of new cancer diagnosis was higher in patients with any bleeding and minor bleeding events than in those without bleeding events (3.3 versus 1.6 per 100 person-years, p < 0.001 and 6.2 versus 1.6 per 100 person-years, p < 0.001, respectively). Multivariate Cox proportional hazard analysis revealed that any bleeding and minor bleeding events were associated with higher rate of new cancer diagnosis [hazard ratio (HR) 2.27, p = 0.003 and HR 3.93, p < 0.001, respectively]. Additionally, any gastrointestinal bleeding and minor gastrointestinal bleeding events were associated with higher rate of new gastrointestinal cancer diagnosis (HR 8.67, p < 0.001 and HR 12.74, p < 0.001, respectively).

CONCLUSIONS

In CAD patients with antiplatelet therapy after PCI, any bleeding and minor bleeding events were associated with subsequent new cancer diagnosis. Even minor bleeding events may be the first manifestation of underlying cancer during antiplatelet therapy after PCI.

Evaluation of the accuracy of heart dose prediction by machine learning for selecting patients not requiring deep inspiration breath‑hold radiotherapy after breast cancer surgery

Increased heart dose during postoperative radiotherapy (RT) for left-sided breast cancer (BC) can cause cardiac injury, which can decrease patient survival. The deep inspiration breath-hold technique (DIBH) is becoming increasingly common for reducing the mean heart dose (MHD) in patients with left-sided BC. However, treatment planning and DIBH for RT are laborious, time-consuming and costly for patients and RT staff. In addition, the proportion of patients with left BC with low MHD is considerably higher among Asian women, mainly due to their smaller breast volume compared with that in Western countries. The present study aimed to determine the optimal machine learning (ML) model for predicting the MHD after RT to pre-select patients with low MHD who will not require DIBH prior to RT planning. In total, 562 patients with BC who received postoperative RT were randomly divided into the trainval (n=449) and external (n=113) test datasets for ML using Python (version 3.8). Imbalanced data were corrected using synthetic minority oversampling with Gaussian noise. Specifically, right-left, tumor site, chest wall thickness, irradiation method, body mass index and separation were the six explanatory variables used for ML, with four supervised ML algorithms used. Using the optimal value of hyperparameter tuning with root mean squared error (RMSE) as an indicator for the internal test data, the model yielding the best F2 score evaluation was selected for final validation using the external test data. The predictive ability of MHD for true MHD after RT was the highest among all algorithms for the deep neural network, with a RMSE of 77.4, F2 score of 0.80 and area under the curve-receiver operating characteristic of 0.88, for a cut-off value of 300 cGy. The present study suggested that ML can be used to pre-select female Asian patients with low MHD who do not require DIBH for the postoperative RT of BC.

Acute coronary syndrome with severe coronary calcification in a patient with pseudo-pseudohypoparathyroidism

A 40-year-old female with a history of steroid therapy for juvenile rheumatoid arthritis was brought to our hospital because of chest pain. A diagnosis of non-ST elevation myocardial infarction was made, and emergency coronary angiography revealed stenotic lesions with severe calcification in the left anterior descending artery and the right coronary artery. Percutaneous coronary intervention with rotational atherectomy followed by a drug-coated balloon was performed to the lesion in the left anterior descending artery. The patient had characteristic physical findings including short stature, a round face, and 'knuckle-dimple sign'. Whole-body computed tomography showed many ectopic calcifications, indicating Albright's hereditary osteodystrophy. Ellsworth-Howard test revealed that urinary cyclic adenosine monophosphate response was positive, thus a diagnosis of pseudo-pseudohypoparathyroidism (PPHP) was made. Here, we describe a rare case of PPHP complicated by acute coronary syndrome with severely calcified coronary arteries.

Learning objective

Pseudo-pseudohypoparathyroidism (PPHP) presents with several characteristic physical findings and ectopic calcifications. Since PPHP involves coronary artery calcification as in the present case, it may be considered as a cause of coronary artery disease.

Targeted expression of bgl23-D, a dominant-negative allele of ATCSLD5, affects cytokinesis of guard mother cells and exine formation of pollen in Arabidopsis thaliana

Targeted expression of bgl23-D, a dominant-negative allele of ATCSLD5, is a useful genetic approach for functional analysis of ATCSLDs in specific cells and tissues in plants. Stomata are key cellular structures for gas and water exchange in plants and their development is influenced by several genes. We found the A. thaliana bagel23-D (bgl23-D) mutant showing abnormal bagel-shaped single guard cells. The bgl23-D was a novel dominant mutation in the A. thaliana cellulose synthase-like D5 (ATCSLD5) gene that was reported to function in the division of guard mother cells. The dominant character of bgl23-D was used to inhibit ATCSLD5 function in specific cells and tissues. Transgenic A. thaliana expressing bgl23-D cDNA with the promoter of stomata lineage genes, SDD1, MUTE, and FAMA, showed bagel-shaped stomata as observed in the bgl23-D mutant. Especially, the FAMA promoter exhibited a higher frequency of bagel-shaped stomata with severe cytokinesis defects. Expression of bgl23-D cDNA in the tapetum with SP11 promoter or in the anther with ATSP146 promoter induced defects in exine pattern and pollen shape, novel phenotypes that were not shown in the bgl23-D mutant. These results indicated that bgl23-D inhibited unknown ATCSLD(s) that exert the function of exine formation in the tapetum. Furthermore, transgenic A. thaliana expressing bgl23-D cDNA with SDD1, MUTE, and FAMA promoters showed enhanced rosette diameter and increased leaf growth. Taken together, these findings suggest that the bgl23-D mutation could be a helpful genetic tool for functional analysis of ATCSLDs and manipulating plant growth.

Quantitative evaluation of the reduction of distortion and metallic artifacts in magnetic resonance images using the multiacquisition variable‑resonance image combination selective sequence

Magnetic resonance imaging (MRI) is superior to computed tomography (CT) in determining changes in tissue structure, such as those observed following inflammation and infection. However, when metal implants or other metal objects are present, MRI exhibits more distortion and artifacts compared with CT, which hinders the accurate measurement of the implants. A limited number of reports have examined whether the novel MRI sequence, multiacquisition variable-resonance image combination selective (MAVRIC SL), can accurately measure metal implants without distortion. Therefore, the present study aimed to demonstrate whether MAVRIC SL could accurately measure metal implants without distortion and whether the area around the metal implants could be well delineated without artifacts. An agar phantom containing a titanium alloy lumbar implant was used for the present study and was imaged using a 3.0 T MRI machine. A total of three imaging sequences, namely MAVRIC SL, CUBE and magnetic image compilation (MAGiC), were applied and the results were compared. Distortion was evaluated by measuring the screw diameter and distance between the screws multiple times in the phase and frequency directions by two different investigators. The artifact region around the implant was examined using a quantitative method following standardization of the phantom signal values. It was revealed that MAVRIC SL was a superior sequence compared with CUBE and MAGiC, as there was significantly less distortion, a lack of bias between the two different investigators and significantly reduced artifact regions. These results suggested the possibility of utilizing MAVRIC SL for follow-up to observe metal implant insertions.

The Prognostic Implications of Living Alone on Long-Term Mortality in Patients with Chronic Coronary Syndrome after Percutaneous Coronary Intervention

Living alone is associated with increased cardiac events and mortality in patients with acute myocardial infarction. However, the prognostic impact of living alone with chronic coronary syndrome (CCS) still remains unclear. In the present study, we examined the relationship between living alone and long-term mortality in patients with CCS who underwent percutaneous coronary intervention (PCI).Consecutive 830 patients with CCS who underwent PCI were enrolled and divided into 2 groups according to whether or not they were living alone at the time of admission (living alone group and non-living alone group). We compared the clinical characteristics between the 2 groups and followed up cardiac mortality. The living alone group was younger compared with the non-living alone group (67.5 versus 70.7 years old, P = 0.017). The prevalence of comorbidities, including coronary risk factors, atrial fibrillation, heart failure, stroke, peripheral artery disease, coronary lesion characteristics, laboratory data, and left ventricular ejection fraction, were comparable between the 2 groups. During the follow-up period (median 1,622 days), 52 cardiac deaths occurred. In the Kaplan-Meier analysis, cardiac mortality was significantly higher in the living alone group than in the non-living alone group (24% versus 11%, P = 0.008). In the multivariable Cox proportional hazard analyses after adjusting for possible confounding factors, living alone was an independent predictor of cardiac mortality (hazard ratio, 2.426, 95% confidence interval 1.225-4.804, P = 0.011).Among CCS patients who underwent PCI, living alone was associated with high long-term cardiac mortality.

Development of a Sensor with a Lipid/Polymer Membrane Comprising Na+ Ionophores to Evaluate the Saltiness Enhancement Effect

The saltiness enhancement effect is the effect whereby saltiness is enhanced by adding specific substances to salt (sodium chloride). Since this effect can be used in the development of salt-reduced foods, a method to objectively evaluate the saltiness with this effect is required. A taste sensor with lipid/polymer membranes has been used to quantify the taste of food and beverages in recent years. The sensor electrodes of this taste sensor have the feature of selectively responding to each of the five basic tastes, which is realized by the lipid/polymer membranes. In this study, we developed a new saltiness sensor based on the lipid/polymer membrane with the aim of quantifying the saltiness enhancement effect. In addition to the conventional components of a lipid, plasticizer, and polymer supporting reagent, the membrane we developed comprises ionophores, which selectively capture sodium ions. As a result, the response of the sensor increased logarithmically with the activity of NaCl in measured samples, similarly to the taste response of humans. In addition, all of the sensor responses increased upon adding saltiness-enhancing substances, such as citric acid, tartaric acid and branched-chain amino acids (BCAAs), to NaCl samples. These findings suggest that it is possible to quantify the saltiness enhancement effect using a taste sensor with lipid/polymer membranes.

Long-term outcomes in Japanese nonagenarians undergoing transcatheter aortic valve implantation: A multi-center analysis

Background and Hypothesis

Japan is an aging society, and the number of nonagenarians with severe aortic stenosis undergoing transcatheter aortic valve implantation (TAVI) is increasing, but their outcomes have not been determined fully.

Methods

We prospectively enrolled 767 consecutive patients who underwent TAVI in three Japanese institutions. Clinical characteristics and outcomes of nonagenarians (n = 94) were evaluated and compared with those of patients aged <90 years (n = 673).

Results

Prevalence of New York Heart Association (NYHA) class III/IV was not different between the two groups. Preoperative risk scores were significantly higher in nonagenarians compared with those in non‐nonagenarians, whereas the Clinical Frailty Scale was not different. Thirty‐day mortality tended to be higher (P = .06) and major vascular complication was significantly higher in nonagenarians than in non‐nonagenarians (P < .05), but 3‐year mortality was equivalent between the two groups. Even after adjustment for covariates, female sex (hazard ratio, 0.41; 95% confidence interval: 0.25‐0.67), body mass index (0.87, 0.80‐0.94), and NYHA class III/IV (1.84, 1.06‐3.29) were associated with all‐cause mortality. Age ≥ 90 years was not associated with all‐cause mortality.

Conclusions

TAVI could be undertaken safely and effectively in nonagenarians, who had acceptable long‐term results compared with those for younger patients, although careful attention should be paid to major vascular complication.

Liver-related safety assessment of green tea extracts in humans: a systematic review of randomized controlled trials

There remain liver-related safety concerns, regarding potential hepatotoxicity in humans, induced by green tea intake, despite being supposedly beneficial. Although many randomized controlled trials (RCTs) of green tea extracts have been reported in the literature, the systematic reviews published to date were only based on subjective assessment of case reports. To more objectively examine the liver-related safety of green tea intake, we conducted a systematic review of published RCTs. A systematic literature search was conducted using three databases (PubMed, EMBASE and Cochrane Central Register of Controlled Trials) in December 2013 to identify RCTs of green tea extracts. Data on liver-related adverse events, including laboratory test abnormalities, were abstracted from the identified articles. Methodological quality of RCTs was assessed. After excluding duplicates, 561 titles and abstracts and 119 full-text articles were screened, and finally 34 trials were identified. Of these, liver-related adverse events were reported in four trials; these adverse events involved seven subjects (eight events) in the green tea intervention group and one subject (one event) in the control group. The summary odds ratio, estimated using a meta-analysis method for sparse event data, for intervention compared with placebo was 2.1 (95% confidence interval: 0.5-9.8). The few events reported in both groups were elevations of liver enzymes. Most were mild, and no serious liver-related adverse events were reported. Results of this review, although not conclusive, suggest that liver-related adverse events after intake of green tea extracts are expected to be rare.

Activation of NK₁ receptors in the locus coeruleus induces analgesia through noradrenergic-mediated descending inhibition in a rat model of neuropathic pain

BACKGROUND AND PURPOSE

The locus coeruleus (LC) is a major source of noradrenergic projections to the dorsal spinal cord, and thereby plays an important role in the modulation of nociceptive information. The LC receives inputs from substance P (SP)-containing fibres from other regions, and expresses the NK(1) tachykinin receptor, a functional receptor for SP. In the present study, we investigated the roles of SP in the LC in neuropathic pain.

EXPERIMENTAL APPROACH

Chronic constriction injury (CCI) of the left sciatic nerve was performed in rats to induce neuropathic pain. After development of neuropathic pain, SP was injected into the LC and the nocifensive behaviours were assessed. The involvement of noradrenergic descending inhibition in SP-induced analgesia was examined by i.t. administration of yohimbine, an α(2) -adrenoceptor antagonist. NK(1) receptor expression in the LC was examined by immunohistochemistry.

KEY RESULTS

In CCI rats, mechanical allodynia was alleviated by SP injection into the LC. These effects were abolished by prior injection of WIN 51708, an NK(1) receptor antagonist, into the LC or i.t. treatment with yohimbine. NK(1) receptor-like immunoreactivity was observed in noradrenergic neurons throughout the LC in intact rats, and remained unchanged after CCI.

CONCLUSION AND IMPLICATIONS

SP in the LC exerted analgesic effects on neuropathic pain through NK(1) receptor activation and resulted in facilitation of spinal noradrenergic transmission. Accordingly, manipulation of the SP/NK(1) receptor signalling pathway in the LC may be a promising strategy for effective treatment of neuropathic pain.

Profile Generation for TV Program Recommendation Based on Utterance Analysis

This paper proposes a method for generating user profile that is to be used for TV program recommendation. The proposed method does not estimate user's interest in a TV program only based on its watching time as most of existing methods do, but also based on user's utterances by applying sentiment analysis. Three kinds of scores are calculated for each watched program, based on which fuzzy inference is performed to estimate its rating. After the estimation, profile structure is obtained by generating category and subcategory layers. This paper mainly focuses on estimation of users' ratings on TV programs. Experiments are performed with test subjects, and the results show the proposed method can improve the estimation accuracy of ratings compared with existing approach using only watching time. Although the proposed method includes language-dependent processing, it is expected the core of estimation rating can be applied to other languages.

Concept of Humatronics and its Application to Human-Robot Communication Support Under TV Watching Environment

In recent years, various systems based on electronics, such as cars, computers and robots have been getting into our daily life. Unfortunately, asymmetrical relationship exists between human and such systems, imposing burdens especially on elderly or handicapped persons. In order to solve various problems for balancing such asymmetrical relationship, humatronics is proposed. Main purpose of humatronics is to establish the symmetric interaction between human and electronic systems by giving the systems the capability of understanding humans. Another important factor for humatronics is computer networks, over which the systems can share knowledge, information, and experiences. This paper introduces the concept of humatronics and its future direction. A prototype of partner robot system, called HuRoC, is also proposed as an application of humatronics concept. It is expected that the concept of humatronics will progress the related research fields by bringing a new viewpoint.

Sphingolipid composition in Bacteroides species

Sphingolipid profiles of strains from species of genus Bacteroides, and representative strains from Prevotella and Porphyromonas, were analyzed by thin-layer chromatography and infrared spectrophotometry. Two major types of phosphosphingolipid, ceramide phosphorylethanolamine and ceramide phosphorylglycerol, were detected in B. fragilis, B. ovatus, B. uniformis, B. caccae, B. eggerthii, B. thetaiotaomicron, and B. stercoris, but not in B. merdae, B. distasonis, and B. vulgatus. Strains from the genera Prevotella and Porphyromonas also contained these two sphingolipids. These sphingolipid profiles were conserved within the species tested, and may be useful for differentiation and recognition of relationships within the genera Bacteroides, Prevotella and Porphyromonas.

Feasibility of reduced intensity hematopoietic stem cell transplantation from an HLA-matched unrelated donor

To evaluate the feasibility of reduced intensity stem cell transplantation (RIST) with bone marrow from a matched unrelated donor (MUD), we retrospectively investigated 20 patients with hematological disorders who received RIST in the Tokyo SCT consortium from January 2000 to October 2002. The preparative regimens were fludarabine-based (150-180 mg/m(2), n=18) or cladribine-based (0.77 mg/kg, n=2). To enhance engraftment, antithymocyte globulin (ATG) and 4 or 8 Gy total body irradiation (TBI) were added to these regimens in nine and 11 patients, respectively. GVHD prophylaxis was cyclosporine with or without methotrexate. In all, 19 achieved primary engraftment. Three developed graft failure (one primary, two secondary), and five died of treatment-related mortality within 100 days of transplant. Seven of the 19 patients who achieved initial engraftment developed grade II-IV acute GVHD, and seven of 13 patients who survived >100 days developed chronic GVHD. At a median follow-up of 5.5 months, estimated 1-year overall survival was 35%. Compared with a TBI-containing regimen, an ATG-containing regimen was associated with a high risk of graft failure (30 vs 0%, P=0.0737). This study supports the feasibility of RIST from MUD; however, procedure-related toxicities remain significant in its application to patients.

Reconstitution of the spliceosomal U1 snRNP from all recombinant subunits and its characterisation by ionspray Q-tof mass-spectrometry

The first important step in pre-mRNA splicing is the recognition of the 5' splice site by the U1 snRNP. It consists of U1 snRNA and 10 protein subunits. We have reconstituted the U1 snRNP from all its ten proteins produced in E. coli and U1 snRNA transcribed in vitro. We have used nano spray time-of-flight (TOF) mass spectrometer in order to characterise the reconstituted U1 snRNP and its sub-assemblies which lack one of more subunits. The reconstituted U1 snRNP and its variants remained intact as multiply charged ions within the mass spectrometer and their mass was determined. By increasing collision energy subparticles are also observed. This method provides information not only about the stoichiometry of subunits within the complex but also about subsets of interacting proteins.

High complete response rate after allogeneic hematopoietic stem cell transplantation with reduced-intensity conditioning regimens in advanced malignant lymphoma

The possible advantage of allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a graft-versus-lymphoma effect. We explored the feasibility and efficacy of allo-HSCT with reduced-intensity (RI) regimens in advanced malignant lymphoma (ML). A total of 20 patients with indolent (n=9) or aggressive lymphoma (n=11) received allo-HSCT with an RI regimen (RIST). The preparative regimen consisted of a combination of purine analog and alkylating agent with or without antithymocyte globulin. A total of 11 patients had chemorefractory disease, seven had chemosensitive relapsed disease and two had residual disease. All of the patients received G-CSF-mobilized blood stem cells from HLA-matched siblings. Of the 20 patients, 19 achieved engraftment with acceptable regimen-related toxicities. Seven patients developed grade II-IV acute GVHD and 15 developed chronic GVHD. Of the 15 patients with evaluable disease, 12 achieved a complete response. One died of invasive fusariosis, four subsequently died of GVHD complicated with fungal infection and one died of progressive disease. With a median follow-up of 358 days, the Kaplan-Meier estimates for 1-year overall and progression-free survival were both 70%. The high response rate with low relapse observed in this study suggests that RIST may be an effective alternative curative treatment for patients with advanced ML.

Sast124, a novel splice variant of syntrophin-associated serine/threonine kinase (SAST), is specifically localized in the restricted brain regions

Syntrophin is an adaptor protein that binds signaling molecules to the dystrophin-associated protein complex, which connects extracellular matrix to intracellular cytoskeleton for construction and maintenance of the postsynaptic structures in the neuromuscular junction and the CNS. Among these signaling molecules, a family of microtubule-associated serine/threonine kinases has a unique structural feature with a serine/threonine kinase domain and a postsynaptic density protein-95/discs large/zona occludens-1 domain. In the present study, we identified syntrophin-associated serine/threonine kinase-124, a novel splice variant of the syntrophin-associated serine/threonine kinase which is a member of the microtubule-associated serine/threonine kinases family. Comparing to the original clone (syntrophin-associated serine/threonine kinase-170), syntrophin-associated serine/threonine kinase-124 is truncated just downstream of the postsynaptic density protein-95/discs large/zona occludens-1 domain. Using a monoclonal antibody specifically recognizing syntrophin-associated serine/threonine kinase-124, strong expression of the protein was observed in neurons of the subventricular zone and granule cells of the olfactory bulb, Islands of Calleja, hippocampal dentate gyrus and cerebellum. syntrophin-associated serine/threonine kinase-124 is selectively localized in the nuclei of neurons and distinct from syntrophin-associated serine/threonine kinase-170, which is interacting with syntrophin on the cell surface. Considering the tissue and subcellular distributions of syntrophin-associated serine/threonine kinase-124, it is suggested that syntrophin-associated serine/threonine kinase-124 may have functions in transcriptional regulation for the features commonly shared by these neurons. On the other hand, syntrophin-associated serine/threonine kinase-124 was also localized in glia-like cell bodies in the corpus callosum and fiber bundles in the spinal trigeminal and solitary tracts, suggesting syntrophin-associated serine/threonine kinase-124 may have other functions in these types of cells.

Absorption and urinary excretion of (-)-epicatechin after administration of different levels of cocoa powder or (-)-epicatechin in rats

(-)-Epicatechin is a major polyphenol component of cocoa powder. The absorption and urinary excretion of (-)-epicatechin following administration of different levels of either cocoa powder (150, 750, and 1500 mg/kg) or (-)-epicatechin (1, 5, and 10 mg/kg) were evaluated in rats. Both the sum of plasma (-)-epicatechin metabolites at 1 h postadministration and peak plasma concentrations increased in a dose-dependent fashion. The sum of (-)-epicatechin metabolites in urine, excreted within 18 h postadministration, also increased with dose. Moreover, the sum of (-)-epicatechin metabolites excreted in urine reached the same level in both (-)-epicatechin and cocoa powder administration groups for equivalent amounts of (-)-epicatechin. These results suggest that, in the dose range examined in this study, bioavailability of (-)-epicatechin following administration of either (-)-epicatechin or cocoa powder shows dose dependence and that the various compounds present in cocoa powder have little effect on the bioavailability of (-)-epicatechin in cocoa powder.

Crystal structure of human AUH protein, a single-stranded RNA binding homolog of enoyl-CoA hydratase

BACKGROUND

The AU binding homolog of enoyl-CoA hydratase (AUH) is a bifunctional protein that has two distinct activities: AUH binds to RNA and weakly catalyzes the hydration of 2-trans-enoyl-coenzyme A (enoyl-CoA). AUH has no sequence similarity with other known RNA binding proteins, but it has considerable sequence similarity with enoyl-CoA hydratase. A segment of AUH, named the R peptide, binds to RNA. However, the mechanism of the RNA binding activity of AUH remains to be elucidated.

RESULTS

We determined the crystal structure of human AUH at 2.2 A resolution. AUH adopts the typical fold of the enoyl-CoA hydratase/isomerase superfamily and forms a hexamer as a dimer of trimers. Interestingly, the surface of the AUH hexamer is positively charged, in striking contrast to the negatively charged surfaces of the other members of the superfamily. Furthermore, wide clefts are uniquely formed between the two trimers of AUH and are highly positively charged with the Lys residues in alpha helix H1, which is located on the edge of the cleft and contains the majority of the R peptide. A mutational analysis showed that the lysine residues in alpha helix H1 are essential to the RNA binding activity of AUH.

CONCLUSIONS

Alpha helix H1 exposes a row of Lys residues on the solvent-accessible surface. These characteristic Lys residues are named the "lysine comb." The distances between these Lys residues are similar to those between the RNA phosphate groups, suggesting that the lysine comb may continuously bind to a single-stranded RNA. The clefts between the trimers may provide spaces sufficient to accommodate the RNA bases.

Blepharismins, produced by the protozoan, Blepharisma japonicum, form ion-permeable channels in planar lipid bilayer membranes

Blepharismins are polycyclic quinones found in the pigment granules of the ciliated protozoan, Blepharisma. Exposure to purified blepharismins results in lethal damage to several other ciliates. We here report that, at cytotoxic concentrations, blepharismins formed cation-selective channels in planar phospholipid bilayer membranes. The channels formed in a diphytanoylphosphatidylcholine bilayer had a K(+)/Cl(-) permeability ratio of 6.6:1. Single channel recordings revealed the conductance to be quite heterogeneous, ranging from 0.2 to 2.8 nS in solutions containing 0.1 M KCl, possibly reflecting different states of aggregation of blepharismin. Our observations suggest that channel formation is a cytotoxic mechanism of blepharismin's action against predatory protozoa.

In vivo comparison of the bioavailability of (+)-catechin, (-)-epicatechin and their mixture in orally administered rats

We compared levels of (+)-catechin, (-)-epicatechin, and their metabolites in rat plasma and urine after oral administration. Rats were divided into four groups and given (+)-catechin (CA group), (-)-epicatechin (EC group), a mixture of the two (MIX group) or deionized water. Blood samples were collected before administration and at designated time intervals thereafter. Urine samples were collected 0-24 h postadministration. (+)-Catechin, (-)-epicatechin and their metabolites in plasma and urine were analyzed by HPLC-mass spectrometry after treatment with beta-glucuronidase and/or sulfatase. After administration, absorbed (+)-catechin and (-)-epicatechin were mainly present in plasma as metabolites, such as nonmethylated or 3'-O-methylated conjugates. In the CA and MIX groups, the primary metabolite of (+)-catechin in plasma was glucuronide in the nonmethylated form. In the EC and MIX groups, in contrast, the primary metabolites of (-)-epicatechin in plasma were glucuronide and sulfoglucuronide in nonmethylated forms, and sulfate in the 3'-O-methylated forms. Urinary excretion of the total amount of (-)-epicatechin metabolites in the EC group was significantly higher than the amount of (+)-catechin metabolites in the CA group. The sum of (+)-catechin metabolites in the urine was significantly lower in the MIX group than in the CA group, and the sum of (-)-epicatechin metabolites in the MIX group was also significantly lower than in the EC group. These results suggest that the bioavailability of (-)-epicatechin is higher than that of (+)-catechin in rats, and that, in combination, (+)-catechin and (-)-epicatechin might be absorbed competitively in the gastrointestinal tract of rats.

Avoiding an overdiagnosis of pancreatic pseudocysts

BACKGROUND/AIMS

Thirty-six cases of pancreatic pseudocysts were retrospectively analyzed, to evaluate the clinical features of the pseudocysts which could not be differentiated from the neoplastic cysts until laparotomy.

METHODOLOGY

Thirty-one out of 36 cases were diagnosed correctly to be a pseudocyst, in which 10 cases (32.3%) were treated by surgery. Five out of 36 cases were diagnosed to be neoplastic pancreatic cysts (mucinous cystadenoma or cystadenocarcinoma in 4 cases, serous cystadenoma in 1) in which all cases were treated by surgery (100%). To determine the clinical factors contributing to a correct or false diagnosis of pseudocysts, 14 clinical objects were categorized into several factors and analyzed using a contingency table.

RESULTS

The clinical factors, including a "history of pancreatitis" (P = 0.070), "upper abdominal pain" (P = 0.083), an "age of less than 42 years" (P = 0.070), and an "elevated serum amylase level on admission" (> or = 200 IU/L, P = 0.067) were all thought to be helpful in establishing a correct diagnosis of pancreatic pseudocyst. In the morphological studies of computed tomography and ultrasonography, "multicystic lesions" (P = 0.045) and "nodular or irregular thickening of the cyst wall" (P = 0.006) significantly mislead us into making a diagnosis of a neoplastic cyst.

CONCLUSIONS

In conclusion, the morphological features of a multicystic pattern, with either nodular or irregular thickening of the cyst wall, also belong to the common features of the pancreatic pseudocysts. Since these features tended to be diagnosed as neoplastic, other clinical factors should thus be referred to, in a comprehensive manner, to establish a correct diagnosis of pancreatic pseudocyst.

Structure and assembly of the spliceosomal snRNPs. Novartis Medal Lecture

The spliceosome is a macromolecular machine that carries out the excision of introns from eukaryotic pre-mRNAs and splicing together of exons. Four large RNA-protein complexes, called the U1, U2, U4/U6 and U5 small nuclear ribonucleoprotein particles (snRNPs), and some non-snRNP proteins assemble around three short conserved sequences within the intron in an ordered manner to form the active spliceosome. We aim to provide insight into the molecular details of the mechanism of pre-mRNA splicing through crystallographic studies of the snRNPs. We have solved the X-ray crystal structure of some snRNP proteins as part of either protein-protein complexes or RNA-protein complexes. These structures have provided an important insight into the overall architecture of the U1 and U2 snRNPs and the mechanisms of RNA-protein and protein-protein recognition.

Role of the Fas system in liver regeneration after a partial hepatectomy in rats

Apoptosis is involved in the homeostatic control of organs. The aim of this study was to define the in vivo role of apoptosis-related proteins including the Fas system and Bcl-2 in liver regeneration following a partial hepatectomy (PH). We used 70% hepatectomized rats which were serially sacrificed from 12 h to 28 days. The expressions of Fas, Fas ligand, and Bcl-2 were examined by semiquantitative RT-PCR and immunohistochemistry. Liver regeneration, as examined by PCNA staining, peaked from 24 h to day 3, and declined from day 5. On the other hand, hepatocyte apoptosis, as examined by TUNEL staining, was seldom observed until 24 h, but increased from 1 week after PH. In the RT-PCR study, Fas showed an early decline by 24 h, followed by a later peak from days 3 to 5, and then a constant expression thereafter. Meanwhile, the Fas ligand was also low until day 3, but showed a remarkable increase from days 5 to 7, followed by a gradual decrease. On the other hand, Bcl-2 showed an early peak until 24 h, followed by a decline from day 5. In an immunohistochemical study, the time courses of these protein expressions were almost synchronous with their mRNAs in the RT-PCR study. We thus conclude that the coordinated interplay between these apoptosis-related proteins and hepatocyte apoptosis suggests the possible involvement of these proteins in the course of liver regeneration.

Successful bone marrow transplantation for adult T-cell leukemia from a donor with oligoclonal proliferation of T-cells infected with human T-cell lymphotropic virus

We describe a patient who underwent successful BMT from her sibling for the treatment of adult T-cell leukemia/lymphoma. Pre-transplant examination of the donor revealed oligoclonal integration of HTLV-I proviruses within the germ line, and our concern was that clinical sequelae of HLTV-I infection might become evident in the setting of post-transplant immunosuppression. However, the patient has been in complete remission for 14 months after transplantation, and no clonality of HTLV-I provirus was detected in the peripheral blood cells using southern blotting analysis. Our experience supports the possibility of transplantation from HTLV-I positive donors.