M Ito

Formation of a borylene by photolysis of an overcrowded bis(methylseleno)borane

Abstract A novel bis(methylseleno)borane 3 bearing a very bulky aryl group, 2,4,6-tris[bis(trimethylsilyl)methyl]phenyl (Tbt), on the boron atom was synthesized. Photolysis of 3 gave the corresponding monovalent boron species, borylene TbtB: (4), the formation of which was confirmed by the trapping reactions with benzil, phenanthrenequinone, and dimethyl disulfide. Irradiation of 3 in the absence of a trapping reagent did not afford the expected diborene but a selenium-containing five-membered boracycle, 1,2,4,3,5-triselenadiborolane 9.

A NOVEL APPROACH TO AN OXOBORANE AND ITS LEWIS BASE COMPLEX

Reaction of dimethyl sulfoxide (DMSO) with 1,3,2,4-dithiastannaboretane 3 bearing an extremely bulky aryl group, 2,4,6-tris[bis(trimethylsilyl)methyl]phenyl (Tbt), on the boron atom gave an oxoborane (Tbt-BO; 4), which formed a complex with DMSO stable in solution. The formation of the complex was confirmed by 11B NMR and a [3+2] cycloaddition reaction with 2,4,6-tri-t-butylbenzonitrile oxide.

FORMATION AND REACTIONS OF A THIOXOBORANE, A NOVEL BORON-SULFUR DOUBLE-BOND COMPOUND

Abstract Thermolysis of an overcrowded tin-containing four-membered boracycle, 1,3,2-dithiastanna-boretane derivative 6 , bearing an extremely bulky aryl group, 2,4,6-tris[bis(trimethylsiyl)methyl]-phenyl (Tbt), on the boron atom in the presence of several 1,3-dienes in toluene at 120 °C gave the corresponding diene adducts of an initially formed thioxoborane (Tbt-B=S; 7 ) together with a trimer of diphenylstannanethione 8 . Retro [4+2]cycloaddition of the diene adducts into the thioxoborane 7 is also described.

A case of fetal vesicoallantoic cyst in the umbilical cord.

A vesicoallantoic cyst in the umbilical cord was detected by fetal ultrasonography at 16 weeks of gestation. The blood flow through the umbilical vessels was evaluated with periodic color Doppler ultrasonographic examinations because compression by the cyst may cause reduction in blood flow and lead to fetal death. After disappearance of the cyst, the infant was delivered vaginally. Retrograde cystography revealed a narrow channel between the bladder and the navel, confirming patent urachus, which was resected without any complications.

Arterial waveforms on doppler ultrasonography predicting or supporting hepatic arterial thrombosis in liver transplantation

HEPATIC arterial thrombosis (HAT) is a major cause of patient morbidity and graft loss in liver transplantation. HAT should be diagnosed before the development of liver parenchymal or bile duct damage. Early diagnosis and treatment are essential to salvage grafts. Doppler ultrasound (US) is a useful tool to diagnose HAT. HAT is diagnosed when arterial flow signals are not detected in the graft. However, waveforms on Doppler US predicting or suggesting HAT are not fully understood. In this study, we investigated whether the waveforms on Doppler US can predict or suggest HAT.

New phenotype of accessory scrotum with perineal lipoblastoma: coexistence of midperineal and lateral accessory scrotums.

Abstract  We present the extremely rare phenotype of an accessory scrotum with an associated lipoblastoma. There was a coexistence of midperineal and lateral types. To our knowledge, this phenotype has never been reported. The lipoblastoma, which arose in the perineum, divided the moving labioscrotal swelling into three parts during early fetal life. This resulted in the specific anomaly in this patient.

Immunosuppressive effect of chenodeoxycholic acid on natural killer cell activity in patients with biliary atresia and hepatitis C virus-related liver cirrhosis.

Patients with severe liver diseases, such as liver cirrhosis and biliary atresia, have low natural killer (NK) cell activity. The relations between NK activity and measures of liver function, including serum levels of total bilirubin, total bile acids, bile acid components, aspartate aminotransferase, and alanine aminotransferase, and platelet count were examined in patients with biliary atresia (6 boys and 6 girls; mean age, 4.8 ± 5.7 years) and patients with liver cirrhosis due to hepatitis C virus infection (10 men and 2 women; mean age, 54.3 ± 13.8 years). Univariate analysis showed that platelet count was positively correlated with NK activity in patients with biliary atresia (r = 0.611, P < 0.05). Serum levels of free chenodeoxycholic acid were negatively correlated with NK activity both in patients with biliary atresia (r = −0.647, P < 0.05) and in patients with hepatitis C virus-related liver cirrhosis (r = −0.876, P < 0.01). None of the other free bile acids or conjugated bile acids or other indicators of liver function were correlated with NK activity. Multiple stepwise regression analysis showed that only levels of free chenodeoxycholic acid were independently correlated with NK activity. All patients with biliary atresia underwent liver transplantation from living related donors. NK activity had increased significantly two months after transplantation (from 24.1 ± 20.2% to 49.2 ± 12.5%, P < 0.01). In contrast, levels of free chenodeoxycholic acid in transplant recipients had decreased significantly two months after transplantation (from 1.22 ± 1.16 to 0.26 ± 0.21 μmol/l, P < 0.05). In conclusion, in patients with biliary atresia or liver cirrhosis, NK activity in peripheral blood decreases, mostly because of free chenodeoxycholic acid.

Increase in natural killer cell activity following living‐related liver transplantation

Abstract We monitored the serial changes of natural killer cell (NK) activity in eight recipients of living‐related liver transplantation. The HLA types of all eight patients were haplotypically identical with those of their donors. Tacrolimus and methylprednisolone were used for immunosuppression. The NK activity before transplantation was 24.1 ± 20.2 % which is surprisingly low when compared with the value for normal individuals (67.7 ± 13.2%, P < 0.01) or a liver dysfunction group (49.4 ± 21.9%, P < 0.05). Serial changes in NK activity revealed a minimum of 6.1 ± 3.6% 1 week after transplantation, gradually increasing to 49.2 ± 12.5 % at 2 months after transplantation. These results suggest that the diseased liver might play an important role in the suppression of NK activity.

Successful repair of the esophagus in type-IV laryngo-tracheo-esophageal cleft using interposed jejunum.

The authors present a female patient of type-IV laryngo-tracheo-esophageal cleft (LTEC) who survived the definitive operation and was discharged from the hospital. Separation of the trachea and the esophagus was very difficult because they formed almost cylindrical common channel and multiple fistulae occurred after the operation. After multiple attempts of closure of the fistulae, one fistula near the carina remained, and the esophagus was reconstructed using interposed jejunum leaving some part of the esophagus connected to the fistula. Now she is practicing oral feeding. This is the fourth long-term survivor of type-IV LTEC in the international literature.

Syntheses, Structures, and Properties of Novel Four-Membered Stannacycles, 1,3,2,4-Dichalcogenastannaboretanes

Syntheses of novel stannacycles, 1,3,2,4-dichalcogenastannaboretane derivatives bearing 2,4,6-tris[bis(trimethylsilyl)methyl]phenyl (Tbt) group on the boron atom are presented. These newly obtained stannacycles were crystallographically analyzed. Thermolyses of these stannacycles are also described.