The hydrocarbon-bearing clathrasil chibaite and its host-guest structure at low temperature.

The natural sII-type clathrasil chibaite [chemical formula SiO2·(M12,M16), where Mx denotes a guest mol-ecule] was investigated using single-crystal X-ray diffraction and Raman spectroscopy in the temperature range from 273 to 83 K. The O atoms of the structure at room temperature, which globally conforms to space group [V = 7348.9 (17) Å3, a = 19.4420 (15) Å], have anomalous anisotropic displacement parameters indicating a static or dynamic disorder. With decreasing temperature, the crystal structure shows a continuous symmetry-lowering transformation accompanied by twinning. The intensities of weak superstructure reflections increase as temperature decreases. A monoclinic twinned superstructure was derived at 100 K [A2/n, V = 7251.0 (17) Å3, a' = 23.7054 (2), b' = 13.6861 (11), c' = 23.7051 (2) Å, ß' = 109.47°]. The transformation matrix from the cubic to the monoclinic system is ai ' = (½ 1 ½ / ½ 0 -½ / ½ -1 ½). The A2/n host framework has Si-O bond lengths and Si-O-Si angles that are much closer to known values for stable silicate-framework structures compared with the averaged model. As suggested from band splitting observed in the Raman spectra, the [512]-type cages (one crystallographically unique in , four different in A2/n) entrap the hydro-carbon species (CH4, C2H6, C3H8, i-C4H10). The [51264]-type cage was found to be unique in both structure types. It contains the larger hydro-carbon mol-ecules C2H6, C3H8 and i-C4H10.

Etiology of recurrent acute pancreatitis, with special emphasis on pancreaticobiliary malformation.

PURPOSE: This study was aimed to investigate etiology and clinical profiles of recurrent acute pancreatitis (RAP), particularly from the morphology of the pancreaticobiliary duct system. MATERIAL AND METHODS: Pancreaticobiliary morphology was examined in 230 of 381 patients with acute pancreatitis (AP) using endoscopic retrograde cholangiopancreatography. We analyzed factors associated with RAP including the pancreaticobiliary duct system. RESULTS: RAP was diagnosed in 74 patients (19%). Major etiologies of RAP were alcoholic (38%), idiopathic (26%) and pancreaticobiliary malformation (22%). Patients with alcoholic RAP were significantly younger (47.2±11.6 years) than those with gallstone RAP (67.3±16.8; p<0.05). RAP with pancreaticobiliary malformation (male-to-female ratio: 1:4.3; p<0.01) and gallstone RAP (1:1.7; p<0.05) occurred predominantly in females in comparison with alcoholic RAP (1:0.2). Recurrence rate was 80% for AP with pancreaticobiliary malformation, significantly higher than for the others (p<0.01). Pancreas divisum was suspected as the etiology of mild RAP in 7 patients. Four RAP patients with pancreas divisum underwent endoscopic minor papilla sphincterotomy and improved. Pancreaticobiliary maljunction with biliary dilatation (choledochal cyst) was suspected as the etiology of mild RAP in 3 patients. The 3 RAP patients with choledochal cyst underwent prophylactic flow diversion surgery with complete resection of the dilated common bile duct, and achieved improvement. High confluence of pancreaticobiliary ducts was suspected as the etiology of mild RAP in 6 patients. CONCLUSION: Pancreaticobiliary malformation is one of the major causes of RAP. As some of them benefit from endoscopic or surgical treatment, morphology of the pancreaticobiliary duct system should be examined where possible in RAP patients.

Endocytoscopic observation for esophageal squamous cell carcinoma: can biopsy histology be omitted?

We examined whether endocytoscopic observation of esophageal squamous cell carcinoma can replace the histologic examination of biopsy specimens. In a basic investigation, we examined 57 iodine-unstained areas in the resected specimens of the esophagus from 28 individuals. The endocytoscopic findings were graded from 0 to 3 in tandem with observations of the iodine staining. For endocytoscopic observation, we sprayed 1% methylene blue or toluidine blue as a vital dye on the surface of the esophageal mucosa, allowing 15-20 s for sufficient staining. One endoscopist observed the target lesions and decided their endocytoscopic type classification. Histological diagnoses were made by two pathologists who were unaware of the endoscopic findings. We then compared the endocytoscopic diagnosis and conventional histological diagnosis. In an in vivo investigation, we examined 71 lesions of esophageal squamous cell carcinoma. Two endoscopists diagnosed the type classification in consultation with a pathologist with regard to 'nuclear density,''nuclear abnormality,' and 'whether biopsy histology could have been omitted on the basis of endocytoscopic findings.' For the in vivo observation, we utilized XEC120U (higher magnification type [x1100]), XEC300F (lower magnification type [x450]), and XGIF-Q260EC1 (lower magnification type [x450]) instruments. In the basic investigation, among the 11 areas classified as Type 1, 10 (91%) were category 1 by the Vienna classification. Among the 39 lesions classified as Type 3, 36 (92%) were category 4 or 5. The sensitivity of endocytoscopy for malignant lesions (Vienna classification categories 4 and 5) was 94.7%, if Type 3 was considered malignant. The specificity was 84.2% according to the same criteria. In the in vivo observation, two endoscopists diagnosed more than 90% of esophageal squamous cell carcinomas as neoplasms using each type of endocytoscope. With regard to nuclear density, the pathologist considered it to be increased in 98% of cases with the XEC120U, in 94% with the XEC300F, and in 93% with the XGIF-Q260EC1. With regard to nuclear abnormality, the positivity rate was 90% with the XEC120U, 78% with the XEC300F, and 80% with the XGIF-Q260EC1. As to whether or not biopsy histology examination was considered necessary, the pathologist made a 'Yes' judgment for 84% of cases observed with the XEC120U, 66% with the XEC300F, and 67% with the XGIF-Q260EC1. Cancerous lesions diagnosed as Type 3 by both endoscopists using the XEC120U accounted for 46 (90.2%) of the 51 cases. Among these 46 cases, biopsy histology was considered unnecessary by the pathologist in 43 (93.5%). We believe that endocytoscopic observation has the potential to reduce the extent of histologic examination of biopsy specimens in cases corresponding to Types 1 and 3 of our classification.

Clinical outcome after endoscopic mucosal resection for esophageal squamous cell carcinoma invading the muscularis mucosae--a multicenter retrospective cohort study.

BACKGROUND AND STUDY AIMS: Endoscopic mucosal resection (EMR) is now commonly indicated for esophageal squamous cell carcinoma (ESCC) within the lamina propria mucosa. However, EMR for ESCC that has invaded the muscularis mucosa is controversial because the risk of lymph node metastasis is not negligible. We conducted a multicenter retrospective cohort study to investigate the incidence of lymph node metastasis and survival after EMR for ESCC invading the muscularis mucosa. PATIENTS AND METHODS: A total of 104 patients with 111 lesions invading the muscularis mucosa, were retrospectively studied at eight institutes. No patients exhibited evidence of metastasis of lymph nodes or distant organs prior to EMR. Overall and cause-specific survival rates were calculated from the date of EMR to the date of death or the most recent follow-up visit. Survival curves were plotted according to the Kaplan-Meier method. RESULTS: In total, 86 patients (82.7%) who did not receive further treatment such as chemotherapy, irradiation therapy, chemoradiotherapy, or esophagectomy after EMR were followed up. Only two patients (1.9%) developed lymph node metastasis after EMR. With a median follow-up period of 43 months (range, 8-134 months), overall and cause-specific survival rates at 5 years after EMR were 79.5% and 95.0%, respectively. CONCLUSIONS: EMR for ESCC that invades the muscularis mucosa has curative potential as a minimally invasive treatment option.

Early esophageal cancer: radiologic estimation of invasion into the muscularis mucosae.

BACKGROUND: Lymph node metastasis in squamous cell carcinoma of the esophagus is rare, and the cancer remains in the lamina propria mucosae. In cases with cancer invading the muscularis mucosae (MM), the incidence of lymph node metastasis is approximately 7%. For endoscopic treatment of mucosal cancer, it is necessary to diagnose cancer invasion into the MM. The aim of this study was to estimate cancer invasion into the MM by esophagography. METHODS: One hundred ten lesions of the slightly depressed type were classified into two groups: in group A, cancer was confined to the lamina propria mucosae; in group B, the cancer invaded the MM or slightly into the submucosa. Radiologic findings of each group were studied. RESULTS: In group A, 69% of 70 lesions showed mild depression and a smooth or undulated surface. Thickened folds were noticed in only 3%. In group B, 83% of 40 lesions showed mild or moderate depression with well-defined granules. Thickened folds were evident in 78%. In the differentiation between groups, the accuracy rates of each finding of moderate depression, well-defined granules, and thickened folds were 85%, 73%, and 90%, respectively. The overall diagnostic accuracy rate was 90%. CONCLUSION: Esophagography is useful for estimation of cancer invasion into the MM and, hence, the decision to apply endoscopic treatment to mucosal cancer.

Super-channel in bacteria: function and structure of the macromolecule import system mediated by a pit-dependent ABC transporter.

In a soil isolate, Sphingomonas sp. A1, the transport of a macromolecule (alginate: 27 kDa) is mediated by a pit-dependent ATP-binding cassette (ABC) transporter. The transporter is different from other ABC transporters so far analyzed in that its function is dependent on a pit, a mouth-like organ formed on the cell surface only when cells are compelled to assimilate macromolecules, and in that it allows direct import of macromolecules into cells. The ABC transporter coupled with the pit, which functions as a funnel and/or concentrator of macromolecules to be imported, was designated the 'super-channel', and in this review, we discuss the three-dimensional structure and specific function of the 'super-channel' for macromolecule import found for the first time in a bacterium.

Super-channel in bacteria: function and structure of a macromolecule import system mediated by a pit-dependent ABC transporter.

In a soil isolate, Sphingomonas sp. A1, the transport of a macromolecule (alginate: 27 kDa) is mediated by a pit-dependent ATP-binding cassette (ABC) transporter. The transporter is different from other ABC transporters so far analyzed in that its function is dependent on the pit, a mouth-like organ formed on the cell surface only when the cells are compelled to assimilate macromolecules, and in that it allows direct import of macromolecules into cells. The ABC transporter coupled with the pit, which functions as a funnel and/or concentrator of macromolecules to be imported, was designated as the "Super-channel", and in this review, we discuss the three-dimensional structure and specific function of the "Super-channel" for macromolecule import found for the first time in a bacterium.

Evaluation of the tocolytic effect of a selective cyclooxygenase-2 inhibitor in a mouse model of lipopolysaccharide-induced preterm delivery.

The inflammatory process is known to cause preterm delivery. Recently, a cyclooxygenase (COX)-2 inhibitor has been developed as an anti-inflammatory drug with few side-effects. We evaluated the COX-2 inhibitor, Celecoxib, for its tocolytic effects and side-effects on dams and pups using a lipopolysaccharide (LPS)-induced preterm delivery mouse model (preterm delivery rates; 95%). With administration of Celecoxib (50, 10, 1 and 0.3 mg/kg), the preterm labour rate was significantly reduced to 18, 30, 36 and 60% respectively. The prostaglandin F(2alpha)(PGF(2alpha)) and PGE(2) concentrations in murine uterine tissue 4 and 10 h after LPS treatment with Celecoxib (10 and 1 mg/kg) were significantly lower than those in the LPS-treated group without CELECOXIB: With administration of 10 or 100 mg/kg Celecoxib, the fetal ductus arteriosus was constricted significantly in preterm and near-term rats, although constriction rates in preterm rats were significantly lower than those in near-term rats. Reproductive and renal functions in offspring whose mothers were treated with LPS and Celecoxib were normal. These data demonstrate that Celecoxib could be used as a new therapy for preterm labour. However, careful attention to constriction of the fetal ductus arteriosus should be given.

The effect of vitamin A on contraction of the ductus arteriosus in fetal rat.

Endogenous retinoic acid may play a role in inducing smooth muscle differentiation in the fetal ductus arteriosus. Maternal administration of retinoic acid may accelerate the process. This study was designed to investigate the effect of vitamin A on developmental changes in the contractile system of the ductus. Vitamin A was injected into pregnant rats and the ductus was isolated from the fetus at 19, 20, or 21 d of gestation. The fetus at 19 d of gestation served as a model of the preterm fetus. The force of contraction and [Ca]i were measured. Membrane depolarization caused by high KCl induced ductal contraction in all age groups studied. In the 19-d fetus, O2 did not cause significant contraction or changes in [Ca]i in the control group, but it did induce a significant contraction and increases in [Ca]i in the vitamin A-treated group. In the 20- and 21-d fetuses, 5% O2-induced contraction in the vitamin A-treated group was significantly greater than in the control group. In the 19-d fetus, noradrenaline-induced contraction and increases in [Ca]i, indicators of the size of the intracellular Ca pool, were observed and they were similar in the control group and in the vitamin A-treated group. These data suggest that 1) in the preterm fetus, the contractile system, including membrane depolarization, [Ca]i increase, and its activation of contractile proteins, is already functioning, but the O2-sensing mechanism is underdeveloped, 2) vitamin A accelerates the development of the O2-sensing mechanism of the ductus arteriosus.

Effects of carvedilol on left ventricular function, mass, and scintigraphic findings in isolated left ventricular non-compaction.

A four month old infant with isolated left ventricular non-compaction was treated with carvedilol. Haemodynamic studies and various types of imaging-including echocardiography, radiographic angiography, magnetic resonance imaging, and single photon emission computed tomography with (201)Tl, (123)I-beta-methyliodophenylpentadecanoic acid (BMIPP), and (123)I-metaiodobenzylguanidine (MIBG)-were performed before and 14 months after treatment. Left ventricular ejection fraction increased from 30% to 57%, and left ventricular end diastolic volume, end systolic volume, and end diastolic pressure showed striking reductions during treatment. Left ventricular mass decreased to about two thirds of the baseline value after treatment. Per cent wall thickening increased after carvedilol in the segments corresponding to non-compacted myocardium. A mismatch between (201)Tl and BMIPP uptake in the area of non-compaction observed before carvedilol disappeared after treatment. Impaired sympathetic neuronal function shown by MIBG recovered after treatment. Thus carvedilol had beneficial effects on left ventricular function, hypertrophy, and both metabolic and adrenergic abnormalities in isolated left ventricular non-compaction.

Tetralogy of Fallot associated with chromosome 22q11.2 deletion in adolescents and young adults.

PURPOSE: To clarify the clinical profiles of adolescents and young adults with tetralogy and 22q11.2 deletion, which has recently been identified as a cause of tetralogy of Fallot in about 15% of patients. METHODS: Thirty-four patients with 22q11.2 deletion and tetralogy of Fallot, with or without pulmonary atresia, including 15 males and 19 females, with their age ranging from 16 to 35 years (mean = 25) were studied. Main outcome measurements include chromosome deletion identified by fluorescence in situ hybridization (FISH) of peripheral blood lymphocytes, medical states assessed with New York Heart Association classification, social activity assessed with Warnes index, IQ assessed by Wechsler test. RESULTS: Eighteen of 20 patients with tetralogy and pulmonary stenosis had cardiac repair, and their cardiac conditions were good except one. Of 14 patients with tetralogy with pulmonary atresia, 7 had Rastelli type cardiac repair and were doing well, although 4 of them needed re-operation for conduit stenosis. No cardiac repair was done in the other 7 patients with tetralogy, pulmonary atresia and major collateral arteries because their peripheral pulmonary arteries were too small. In 28 of the 34 patients (82%), overall social activity was limited because of extracardiac diseases, including deafness, club feet, mental retardation, and schizophrenia. The IQ in 17 patients was 59 +/- 13 (mean +/- SD): range 41 to 79. In two patients, repeated IQ study showed a decrease. Four patients developed schizophrenia. CONCLUSION: Tetralogy with 22q11 deletion can be repaired surgically except in those patients with pulmonary atresia, major collateral arteries, and small peripheral pulmonary arteries. However, most of the adult patients show an inability to function in social life in contrast to most patients with tetralogy but without the deletion, who have a normal social life. Extracardiac diseases, including deafness, club feet, mental retardation, and schizophrenia were major handicaps limiting full social activities in postoperative adolescents and young adults with 22q11.2 deletion and tetralogy.

Crystallization and preliminary X-ray analysis of AlgS, a bacterial ATP-binding cassette (ABC) protein specific to macromolecule import.

Sphingomonas sp. A1 possesses a macromolecule (alginate; average molecular size 25 700 Da) uptake system mediated by a novel pit-dependent ABC transporter. In this system, AlgS (363 amino-acid residues; 40 kDa) functions as an ATPase and provides energy for the translocation of high molecular-weight alginate across the cytoplasmic membrane. Hexahistidine-tagged AlgS of Sphingomonas sp. A1 was overexpressed in Escherichia coli and crystallized by means of the hanging-drop vapour-diffusion method with ammonium dihydrogen monophosphate as the precipitant. Preliminary X-ray analysis of the resultant crystals was performed; they belonged to the monoclinic space group P2(1) and had unit-cell parameters a = 57.4, b = 92.7, c = 65.8 A, beta = 102.3 degrees. X-ray diffraction data to 3.2 A have been collected from the native crystal.

Comparison of three-dimensional contrast-enhanced magnetic resonance angiography and axial radiographic angiography for diagnosing congenital stenoses in small pulmonary arteries.

Accuracy of 3-dimensional contrast-enhanced magnetic resonance angiography (MRA) in diagnosing morphology of the branch pulmonary artery (PA) was evaluated in 73 patients (aged 7.2 +/- 6.4 years [mean +/- SD]) with various congenital heart diseases. The presence or absence of localized stenosis of branch PAs, PA diameter, and Nakata's PA index were determined on MRA and axial radiographic angiography, and the results were compared. Sensitivity, specificity, and overall accuracy in detecting branch PA stenoses were 92.7%, 96.2%, and 95.2%, respectively. Correlations between axial radiographic angiography and MRA were excellent in measuring PA diameter (r = 0.956, SEE = 1.49 mm, n = 139) as well as PA index (r = 0.839, SEE = 48.9, n = 37); both p < 0.0001. Bland-Altman plots showed a mean difference +/- SD for PA diameter of 0.17 +/- 1.51 mm and for PA index of 8.5 +/- 50.1. When the main right and left PAs were taken as the first generation, the most distal branches visible on MRA were the 4.7 +/- 0.7 generation with breath-holding (n = 23) and the 3.7 +/- 0.5 without breath-holding (n = 50), respectively (p < 0.0001). Both intra- and interobserver variabilities of MRA measurements were few (9.5 +/- 11.6% and 13.5 +/- 15.0%, respectively, n = 139). In conclusion, 3-dimensional contrast-enhanced MRA enables us to document branch PA morphology clearly in infants and adult patients with congenital cardiovascular defects.

Safety assessment of rice genetically modified with soybean glycinin by feeding studies on rats.

Feeding studies on rice genetically modified with soybean glycinin were performed on rats for four weeks. The rats were divided into three groups, each being fed on (I) only a commercial diet, (II) this diet plus control rice and (III) this diet plus rice genetically modified with glycinin. The rats were fed with 10 g/kg-weight of rice every day by oral administration. During the test period, the rats in every group grew well without marked differences in appearance, food intake, body weight, or cumulative body weight gain. There were also no significant differences in the blood count, blood composition or internal organ weights among the rats. Necropsy at the end of the experiment indicated neither pathological symptoms nor histopathological abnormalities in the liver and kidney. Judging from these results, the rice genetically modified with glycinin is considered to have been essentially the same in nutritional and biochemical characteristics as the control rice.

Long-term effect of angiotensin-converting enzyme inhibitor in volume overloaded heart during growth: a controlled pilot study.

OBJECTIVES: This study examined whether long-term therapy with an angiotensin-converting enzyme (ACE) inhibitor reduces excessive increases in left ventricular (LV) mass as well as volume in growing children with aortic regurgitation or mitral regurgitation. BACKGROUND: The ACE inhibitor reduces volume overload and LV hypertrophy in adults with aortic or mitral regurgitation. METHODS: This study included 24 patients whose ages ranged from 0.3 to 16 years at entry to the study. On echocardiography, we measured LV size, systolic function and mass. After obtaining baseline data, patients were allocated into two groups. Twelve patients were given an ACE inhibitor (ACE inhibitor group), and 12 patients were not (control group). Echo parameters were again assessed after an average 3.4 years of follow-up. RESULTS: Left ventricular parameters at baseline in the two groups were similar. The Z value of LV end-diastolic dimensions decreased from +0.82 +/- 0.55 to +0.57 +/- 0.58 in the ACE inhibitor group, whereas it increased from +0.73 +/- 0.85 to +1.14 +/- 1.04 in the control group (mean change -0.25 +/- 0.33 for the ACE inhibitor group vs. +0.42 +/- 0.48 for the control group, p = 0.0007). The mass normalized to growth also reduced from 221 +/- 93% to 149 +/- 44% of normal in the ACE inhibitor group and increased from 167 +/- 46% to 204 +/-59% of normal in the control group (mean change -72 +/- 89% of normal for the ACE inhibitor group vs. +37 +/- 35% of normal for the control group, p = 0.0007). CONCLUSIONS: Long-term treatment with ACE inhibitors is effective in reducing not only LV volume overload but also LV hypertrophy in the hearts of growing children with LV volume overload.

Molecular identification of oligoalginate lyase of Sphingomonas sp. strain A1 as one of the enzymes required for complete depolymerization of alginate.

A bacterium, Sphingomonas sp. strain A1, can incorporate alginate into cells through a novel ABC (ATP-binding cassette) transporter system specific to the macromolecule. The transported alginate is depolymerized to di- and trisaccharides by three kinds of cytoplasmic alginate lyases (A1-I [66 kDa], A1-II [25 kDa], and A1-III [40 kDa]) generated from a single precursor through posttranslational autoprocessing. The resultant alginate oligosaccharides were degraded to monosaccharides by cytoplasmic oligoalginate lyase. The enzyme and its gene were isolated from the bacterial cells grown in the presence of alginate. The purified enzyme was a monomer with a molecular mass of 85 kDa and cleaved glycosidic bonds not only in oligosaccharides produced from alginate by alginate lyases but also in polysaccharides (alginate, polymannuronate, and polyguluronate) most efficiently at pH 8.0 and 37 degrees C. The reaction catalyzed by the oligoalginate lyase was exolytic and thought to play an important role in the complete depolymerization of alginate in Sphingomonas sp. strain A1. The gene for this novel enzyme consisted of an open reading frame of 2,286 bp encoding a polypeptide with a molecular weight of 86,543 and was located downstream of the genes coding for the precursor of alginate lyases (aly) and the ABC transporter (algS, algM1, and algM2). This result indicates that the genes for proteins required for the transport and complete depolymerization of alginate are assembled to form a cluster.

A novel bacterial ATP-binding cassette transporter system that allows uptake of macromolecules.

A gram-negative bacterium, Sphingomonas sp. strain A1, isolated as a producer of alginate lyase, has a characteristic cell envelope structure and forms a mouth-like pit on its surface. The pit is produced only when the cells have to incorporate and assimilate alginate. An alginate uptake-deficient mutant was derived from cells of strain A1. One open reading frame, algS (1,089 bp), exhibiting homology to the bacterial ATP-binding domain of an ABC transporter, was cloned as a fragment complementing the mutation. algS was followed by two open reading frames, algM1 (972 bp) and algM2 (879 bp), which exhibit homology with the transmembrane permeases of ABC transporters. Disruption of algS of strain A1 resulted in the failure to incorporate alginate and to form a pit. Hexahistidine-tagged AlgS protein (AlgS(His6)) overexpressed in Escherichia coli and purified by Ni(2+) affinity column chromatography showed ATPase activity. Based on these results, we propose the occurrence of a novel pit-dependent ABC transporter system that allows the uptake of macromolecules.