CO2 regulates molecular rotor dynamics in porous materials.

A crystalline hydrogen-bonded framework with permanent porosity, built by rod-like struts and engineered to bear ultra-fast molecular rotors between two triple bonds, offers the possibility of controlling the rotational rates upon CO2 adsorption. CO2 enters the pores from the gas phase and reduces the rotational rates from the extremely fast regime of 107 Hz at 216 K to 105 Hz. The CO2-rotor interaction was evident from the 2H NMR response to the dynamics of the rotors in contact with CO2 in the crystal structure.

A new technique for early detection of portal vein and arterial thromboses. Indwelling mesenteric venous catheterization and relevance to small bowel transplantation.

The aim of this study was to ascertain whether, in an animal model, continuous monitoring of mesenteric venous pressure (MVP) via an indwelling mesenteric venous catheter could assist in early detection of thrombosis of the portal vein (PVT) and superior mesenteric artery (SMAT). The role of portography via the catheter was also studied in confirming these complications. An animal model of PVT and SMAT was developed in pigs. At laparotomy, a 20-cm jejunal loop was isolated and a heparin-coated catheter was inserted into a mesenteric vein of the isolated jejunum and connected to a pressure transducer. Conditions of PVT were simulated by progressive occlusion of the portal vein (PV) using a silastic tourniquet and those of SMAT by superior mesenteric artery (SMA) clamping. MVPs (mm Hg) were found to significantly increase with all degrees of PV occlusion (P < 0.01, Student's t test) and to significantly decrease after SMA occlusion (P < 0.01). Portography clearly demonstrated all degrees of PV stenosis after PV occlusion and stasis of contrast medium during SMA occlusion. The authors feel that this method enables rapid diagnosis of PVT and SMAT and may be useful in the monitoring of the therapy for these complications after small bowel transplantation.

Transplantation of infantile bladder in rats: an alternative procedure for bladder augmentation.

BACKGROUND: Our purpose was to evaluate whether bladder transplantation (BTx) can be used for bladder augmentation (BA). METHODS: Bladders from infantile Brown-Norway rats (less than 21 days old) were excised and each transplanted into a pouch created in the distal omentum of a 6-week-old Lewis rat (fully allogeneic BTx). No immunosuppressant was used in group I (n=12). Intramuscular FK506 was used daily from the day of BTx in group II (n=16; 0.2 mg/kg), group III (n=22; 0.6 mg/kg), and group IV (n=16; 1.2 mg/kg) until harvesting 3, 4, 5, or 6 weeks after BTx. FK506 was used for only 2 weeks in group V (n=12; 0.6 mg/kg/day) and group VI (n=12; 1.2 mg/kg/day). Syngeneic bladder transplants acted as controls (n=16). Hematoxylin and eosin staining was used to examine all grafts. In six rats from group III, BA was performed by anastomosing the graft to the recipient bladder 10 days after BTx. RESULTS: Each successfully transplanted graft appeared macroscopically as a thin-walled cyst. Rejection was seen in all grafts from groups I, II, V, and VI, and was minimal or absent in groups III and IV. On medium to long-term follow-up the only side effect of FK506 observed was reduced weight gain. Graft survival in the control group was 100%. BA was successful in all six cases, and the mucosa was normal throughout each augmented bladder. CONCLUSIONS: This is the first report of the successful transplantation of infantile tissue without vascular anastomosis. Because of the efficient, safe immunosuppression possible with FK506, our BTx technique could find clinical application for creating viable vesical tissue that could be used for BA.

Treatment of biliary atresia: microsurgery for hepatic portoenterostomy.

Microsurgery was used for hepatic portoenterostomy as the treatment of biliary atresia in 46 patients whom we treated since 1972. The microscope had a higher power (eight or ten times) magnification. As for the results of the operative procedure with the microscope, of 46 patients, 32 (70 percent) showed satisfactory bile flow postoperatively.

An annular pancreas derived from paired ventral pancreata, supporting Baldwin's hypothesis.

An annular pancreas is a rare malformation. It is generally accepted that the ring formation originates from a single ventral pancreas, as suggested by Lecco. No reports of resected and/or autopsied annular pancreata derived from paired ventral pancreata, thus supporting Baldwin's hypothesis, have been published. We describe an annular pancreas originating from paired ventral pancreata, thus supporting Baldwin's hypothesis, and attempt to clarify the pathogenesis of an annular pancreas. The patient was a 1-day-old Japanese male newborn, born at 32 weeks of pregnancy. He died from respiratory failure owing to esophageal atresia the next day. Autopsy incidentally revealed an annular pancreas that was examined histologically. Multiple 4 microm thick serial sections were obtained from paraffin-embedded pancreatic tissue. Sections for histologic analysis were subjected to hematoxylin-eosin staining and pancreatic polypeptide immunostaining. An unusually large pancreatic duct encircled by pancreatic tissue ran around the duodenum, and the duct was confirmed to flow into the major papilla. The islets of the encircling pancreas were positive for pancreatic polypeptide. A normal main and accessory pancreatic duct were also identified. Histologic and immunohistochemical evaluation revealed that the ring formation originated from the left lobe of paired ventral pancreata. An annular pancreas that was investigated histopathologically and immunohistochemically and found to support Baldwin's hypothesis is described.

Induction of immediate-early, ornithine decarboxylase and antizyme gene expression in the rat small intestine after transient ischaemia.

The expression of the immediate early genes (IEG)s c-fos, c-jun and zif/268, and the genes coding for ornithine decarboxylase (ODC) and its regulatory protein antizyme (AZ), was studied in rat small intestine following transient ischemia. The ischemic stimulus for 10 min alone did not alter the expression of these genes. A rapid and transitory induction of all IEG mRNAs occurred in a coordinated manner peaking at 30 min following recirculation and returned to basal levels 3 hr after recirculation. Protein products of the IEGs accumulated in the smooth muscle layer of the intestine by 2-3 hr after recirculation. Expression of both ODC and AZ mRNAs initially decreased to 70% of control levels 1 hr after recirculation but markedly increased at 2 to 4 hr after recirculation. The functional significance of these changes in gene expression in relation to tissue integrity and function after the ischaemia/reperfusion is discussed.

Ursodeoxycholic acid therapy in the treatment of biliary atresia.

The prognosis of operated biliary atresia in the cases with bile excretion chiefly depends upon the prevention of ascending cholangitis. An antibiotic is therefore intravenously administered during the early postoperative phase, but cannot be used over a long period. In the cases showing satisfactory bile excretion after operation, ascending cholangitis is rare because of rapid disappearance of jaundice. Regarding this, the authors prescribed ursodeoxycholic acid (UDCA) at 10-15 mg/kg/day to 6 infants with biliary atresia for several weeks after operation, and then determined the effects of UDCA in improving jaundice and bile excretion. As a result, serum bilirubin and serum total bile acid (STBA) levels were decreased in 4 of the 6 infants. In the remaining 2 infants, their STBA levels showed no decrease, but were rather increased; these infants subsequently died of hepatic failure. These results suggested that UDCA is useful in the treatment of cholestasis associated with biliary atresia in the cases attaining postoperative bile excretion. It was also suggested that the treatment with UDCA should be stopped when the STBA levels increased after the beginning of the treatment. Therefore, it was thought that STBA levels measured during UDCA therapy could serve as a good indicator of the choleretic effect of UDCA.

Congenital biliary dilatation.

Congenital biliary dilatation is commonly associated with pancreaticobiliary malunion. Its etiology remains unknown. With the advent of accurate cholangiography, combined abnormalities of the intrahepatic duct, common channel, and pancreatic duct are being identified more frequently in patients with congenital biliary dilatation. Early diagnosis followed by cyst excision is the treatment of choice, even in asymptomatic cases. The treatment of intrahepatic and intrapancreatic ductal diseases such as intrahepatic duct dilatation and stone debris in the intrahepatic duct and common channel are also discussed. The value of intraoperative endoscopy as an adjunct to cyst excision for the prevention of postoperative complications is explained.

Fertilization of bovine oocytes grown in vitro.

Early antral follicles 0.5-0.7 mm in diameter were dissected from bovine ovaries, and oocyte-cumulus complexes with pieces of parietal granulosa (OCCGs) were then collected from the follicles. The OCCGs containing oocytes of 90-99 microm diameter (94.7+/-2.8 microm, n = 196) were selected and embedded in collagen gels and cultured for 14 days in TCM199 containing 10% fetal calf serum and 4 mM hypoxanthine. From cultured OCCGs, 144 surviving oocytes were recovered, of which 53 were granulosa cell-enclosed oocytes and 91 were denuded oocytes. The mean diameter of the surviving oocytes was 114.2+/-8.4 microm, significantly larger than that measured before culture (P < 0.05). The granulosa cell-enclosed oocytes and denuded oocytes were further cultured for maturation for 24 h. After culture, 72% (38/53) of the granulosa cell-enclosed oocytes and 59% (54/91) of the denuded oocytes showed normal morphology. These oocytes were then inseminated with bovine spermatozoa. After 29 h of insemination, all of the denuded oocytes had degenerated, while 32% (12/38) of the granulosa cell-enclosed oocytes showed normal morphology. Of the 12 oocytes, 5 were penetrated by spermatozoa, and 2 formed both male and female pronuclei. These results demonstrate for the first time that bovine oocytes grown in vitro acquire meiotic competence and can be penetrated by spermatozoa.

Structural study of a new antitumor antibiotic, kazusamycin.

The structure of a new antitumor antibiotic, kazusamycin produced by Streptomyces sp. No. 81-484, was determined on the basis of its spectral and chemical properties. Kazusamycin has a structure characteristic of an unsaturated, branched-chain fatty acid with a terminal delta-lactone ring.

A new antitumor antibiotic, awamycin.

A new antibiotic, awamycin, was isolated from the culture broth of Streptomyces sp. No. 80-217. It appeared to belong to the quinone indicator group from results of physicochemical studies and has the empirical formula C38H49NO12S. This antibiotic possessed antibacterial and antitumor activities against Gram-positive bacteria and experimental murine tumors. The antibiotic also showed direct cytotoxic activity against HeLa cells in vitro.

A new antitumor antibiotic, kazusamycin.

A new antibiotic kazusamycin, was isolated from the culture broth of Streptomyces sp. No. 81-484, which shows antitumor activity against experimental murine tumors. This antibiotic did not possess antibacterial activity against Gram-positive and Gram-negative bacteria, but showed strong cytotoxic activity against HeLa cells in vitro. The chemical and physico-chemical properties of kazusamycin suggest that the molecular formula of this antibiotic is C33H48O7 (MW 556).

Biosynthesis of fluorothreonine and fluoroacetic acid by the thienamycin producer, Streptomyces cattleya.

An antimetabolite, THX, was isolated from fermentation broths of the thienamycin producer, Streptomyces cattleya, when the organism was grown in the presence of a fluorine-containing substrate. THX was subsequently identified as one of the four possible stereoisomers of 4-fluorothreonine. Inorganic fluoride or any one of a number of organofluorine compounds can be used as precursors of 4-fluorothreonine. In addition, 19F NMR has provided evidence that the organism synthesizes fluoroacetate under the same fermentation conditions. The in vitro antibacterial spectrum of 4-fluorothreonine is also presented.

Dynamical instability of the motion of atoms in a silicon crystal.

The dynamical nature of the motion of atoms in a silicon crystal is investigated from the information theoretic standpoint with time series analysis about numerical solutions of molecular dynamics simulation. The atomic motion exhibits exponential decay of information entropy with a characteristic time scale of approximately 40 x 10(-15) sec. This observation may be interpreted as a signature of microscopic dynamical instability in solids.

Bile pancreatitis.

Bile pancreatitis was studied both macropathologically and histopathologically in cases with an abnormal pancreatic choledochoductal junction, in which free communication between the pancreatic duct and the common bile duct occurred. The intraductal pressure of the pancreatic duct is normally higher than that of the bile duct, therefore, the pancreatic juice flows into the bile duct. In this study, we found squamous carcinoma cells from an adeno-squamous cell carcinoma of the gall-bladder in the main pancreatic duct. Hence, the possibility of bile reflux into the pancreatic duct was also considered. Outstanding findings, such as degeneration and disappearance of the pancreatic ductal epithelium, intraluminal aggregation of bacilli, and diffuse interlobular fibrosis were found in four of 15 cases with an abnormal junction. Similar ductal alterations and diffuse fibrosis were found neither in the controls nor in the remaining 11 cases. Therefore, it appears that pancreatic disorders due to the reflux of bile occurs in the presence of bacteria.

Microbial community analysis in the denitrification process of saline-wastewater by denaturing gradient gel electrophoresis of PCR-amplified 16S rDNA and the cultivation method.

The metallurgic wastewater generated from the processes of recovering precious metals from industrial wastes contains high concentrations of nitrogen compounds and salts. Biological nitrogen removal from this wastewater was attempted using a circulating bioreactor system equipped with an anaerobic packed bed or an anaerobic fluidized bed. The denitrification capability of the system with the anaerobic packed bed was more stable than that of the system with the anaerobic fluidized bed. The NOx removal rate of the anaerobic packed bed was as high as 97%. Microbial community analysis by denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S ribosomal DNA (rDNA) fragments and the cultivation method revealed that the community diversity varied in accordance with wastewater composition such as the level of salinity and so on. Phylogenetic analysis suggested that the taxonomic affiliation of the dominant species in the anaerobic reactors was to the gamma-Proteobacteria including Halomonadaceae species. The PCR-DGGE method as a non-cultivation method was found to be a powerful tool for analysis of the microbial community, because the cultivation method could detect only a fraction of the microbial species present in these systems. The genetic diversity of the isolated bacteria belonging to the gamma-Proteobacteria which reduced both nitrate and nitrite in the anaerobic packed bed was higher than that of the bacteria in the anaerobic fluidized bed. This suggested that a genetically diverse microbial community stabilized the denitrifying performance in the anaerobic packed bed.

New operative technique for Hirschsprung's disease.

A new technique for definitive surgery in Hirschsprung's disease is described. After transection of the rectum at 2 cm above the peritoneal reflection, the distal rectum is incised laterally on both sides in a longitudinal direction half way to the anus. The mucosal lining of the anterior rectum is partially removed. The posterior portion of the rectum is divided into two flaps by sagittal incision up to the mucocutaneous junction of the anus, which are then reflected and everted through the anus. The proximal colon is then pulled through, exteriorizing 5 cm of ganglionic colon. The exteriorized colon is resected two weeks later. Nine cases were operated upon by this technique. The postoperative results were satisfactory in all cases.

Indication for portoenterostomy based on 103 patients with Suruga II modification.

Although the prognosis of biliary atresia has greatly advanced, only two thirds of patients are able to survive for a long time. This study was designed to investigate the correlation between liver fibrosis, size of ductuli at porta hepatis, and prognosis in order to determine the indications for the Kasai operation. The results of this study showed that the more severe fibrosis of the liver becomes, the worse will be the postoperative clinical features, and the larger the size of ductuli at porta hepatis, the better the prognosis. Based on these results, we have concluded that it is often possible to predict the prognosis at radical surgery by evaluating frozen sections. Patients can be divided into three groups according to these histological findings: group 1 (correctable, or RI in F1); group 2 (RII in F1, RI or RII in F2); group 3 (RIII, RI, or RII in F3). Although the Kasai operation is definitely indicated for patients in groups 1 and 2, making a stoma should be avoided in group 2, because the possibility of liver transplantation may arise in the future. Meanwhile, there is no indication for the Kasai operation for the patients in Group 3, liver transplantation is recommended.

A new clinical prognostic predictor for patients with biliary atresia.

The excretion of D-glucaric acid (DGA), a metabolite of the cytochrome P-450 pathway, is considered a marker of the viability of hepatocytes. Twelve cases of biliary atresia (BA) have been investigated, correlating the level of DGA, degree of histological alteration of liver parenchyma, and clinical outcome. Urine was collected in the preoperative period. Five patients had good bile flow after the Kasai operation and demonstrated mild liver fibrosis. The urine excretion level of DGA in this group was 17.2 +/- 3.1 mumol/d (control, 15.2 + 2.2 [67od] mmol/d). Seven patients had partial bile drainage or prolonged jaundice. They also had altered liver parenchyma and a very low level of DGA in the urine preoperatively (4.2 + 2.2 mumol/d). Urine excretion of DGA reflected the degree of alteration of liver parenchyma and closely correlated with clinical outcome. Measurement of DGA before the Kasai operation provides information concerning the present hepatic function and the postoperative prognosis. Once the activity of hepatocytes deteriorates, this test is quicker than the other liver function tests. It is noninvasive and is a useful clinical prognostic predictor in BA.