On-line preconcentration using dual mini-columns for the speciation of chromium(III) and chromium(VI) and its application to water samples as studied by inductively coupled plasma-atomic emission spectrometry

On-line preconcentration system for the selective, sensitive and simultaneous determination of chromium species was investigated. Dual minicolumns containing chelating resin were utilized for the speciation and preconcentration of Cr(III) and Cr(VI) in water samples. In this system, Cr(III) was collected on first column packed with iminodiacetate resin. Cr(VI) in the effluent from the first column was reduced to Cr(III), which was collected on the second column packed with iminodiacetate resin. Hydroxyammonium chloride was examined as a potential reducing agent for Cr(VI) to Cr(III). The effects of pH, sample flow rate, column length, and interfering ions on the recoveries of Cr(III) were carefully studied. Five millilitres of a sample solution was introduced into the system. The collected species were then sequentially washed by 1 M ammonium acetate, eluted by 2 M nitric acid and measured by ICP-AES. The detection limit for Cr(III) and Cr(VI) was 0.08 and 0.15 mu g l-1, respectively. The total analysis time was about 9.4 min. The developed method was successfully applied to the speciation of chromium in river, tap water and wastewater samples with satisfied results. </p

A highly distinctive mechanical property found in the majority of human promoters and its transcriptional relevance

A recent study revealed that TATA boxes and initiator sequences have a common anomalous mechanical property, i.e. they comprise distinctive flexible and rigid sequences when compared with the other parts of the promoter region. In the present study, using the flexibility parameters from two different models, we calculated the average flexibility profiles of 1004 human promoters that do not contain canonical promoter elements, such as a TATA box, initiator (Inr) sequence, downstream promoter element or a GC box, and those of 382 human promoters that contain the GC box only. Here, we show that they have a common characteristic mechanical property that is strikingly similar to those of the TATA box-containing or Inr-containing promoters. Their most interesting feature is that the TATA- or Inr-corresponding region lies in the several nucleotides around the transcription start site. We have also found that a dinucleotide step from −1 to +1 (transcription start site) has a slight tendency to adopt CA that is known to be flexible. We also demonstrate that certain synthetic DNA fragments designed to mimic the average mechanical property of these 1386 promoters can drive transcription. This distinctive mechanical property may be the hallmark of a promoter

Resection of Segments 4, 5 and 8 for a Cystic Liver Tumor Using the Double Liver Hanging Maneuver

To achieve complete anatomic central hepatectomy for a large tumor compressing surrounding vessels, transection by an anterior approach is preferred but a skillful technique is necessary. We propose the modified technique of Belghiti's liver hanging maneuver (LHM). The case was a 77-year-old female with a 6-cm liver cystic tumor in the central liver compressing hilar vessels and the right hepatic vein. At the hepatic hilum, the spaces between Glisson's pedicle and hepatic parenchyma were dissected, which were (1) the space between the right anterior and posterior Glisson pedicles and (2) the space adjacent to the umbilical Glisson pedicle. Two tubes were repositioned in each space and ‘double LHM’ was possible at the two resected planes of segments 4, 5 and 8. Cut planes were easily and adequately obtained and the compressed vessels were secured. Double LHM is a useful surgical technique for hepatectomy for a large tumor located in the central liver

Multiple rectal carcinoids with diffuse ganglioneuromatosis

BACKGROUND: Rectal carcinoids comprise only about 1% of all anorectal neoplasms. In addition, ganglioneuroma of the gastrointestinal tract is a rare tumor composed ganglion cells, nerve fibers, and supporting cells. Multiple carcinoid tumors with diffuse ganglioneuromatosis limited to the rectum are quite unusual. CASE PRESENTATION: A 69-year-old man was referred to us because of about 100 small submucosal rectal tumors. He underwent abdominoperineal resection. Pathology revealed carcinoid tumors for about 30 submucosal nodules and diffuse ganglioneuromotosis. To date (6 months later) he remains well with no recurrence. CONCLUSION: Although the optimal treatment for the multiple rectal carcinoids remains to be clearly established, it is believed that not all patients with multiple rectal carcinoids (measuring less than 1 cm in diameter) need to have a radical operation. However, the treatment plan for each case should be individualized and a careful follow-up is mandatory

Combined transabdominal and transperineal endoscopic pelvic exenteration for colorectal cancer: feasibility and safety of a two-team approach

Purpose: Pelvic exenteration (PE) is a highly invasive procedure with high morbidity and mortality rates. Promising options to reduce this invasiveness have included laparoscopic and transperineal approaches. The aim of this study was to identify the safety of combined transabdominal and transperineal endoscopic PE for colorectal malignancies.Methods: Fourteen patients who underwent combined transabdominal and transperineal PE (T group: 2-team approach, n = 7; O group: 1-team approach, n = 7) for colorectal malignancies between April 2016 and March 2020 in our institutions were included in this study. Clinicopathological features and perioperative outcomes were compared between groups.Results: All patients successfully underwent R0 resection. Operation time tended to be shorter in the T group (463 minutes) than in the O group (636 minutes, P = 0.080). Time to specimen removal was significantly shorter (258 minutes vs. 423 minutes, P = 0.006), blood loss was lower (343 mL vs. 867 mL, P = 0.042), and volume of blood transfusion was less (0 mL vs. 560 mL, P = 0.063) in the T group, respectively. Postoperative complications were similar between groups.Conclusion: Combined transabdominal and transperineal PE under a synchronous 2-team approach was feasible and safe, with the potential to reduce operation time, blood loss, and surgeon stress

An experience of treatment of postoperative biliary stricture at a single Japanese institute.

Many causes of biliary stricture are iatrogenic including postoperative complication such as a cholecystectomy. We examined the clinical demographics, surgical records and outcome in 7 patients undergoing biliary surgery between 1994 and 2006. Diseases included gall stone in 6 patients and neuroendocrine tumor of the pancreas head in one. Causes of biliary stricture included bile duct injury during cholecystectomy in 4 patients, and stenosis of hepaticojejunostomy in 3 (Repair of biliary injury in two and reconstruction after pancreaticoduodenectomy (PD) in one). Treatment modalities included surgical resection of stricture and reconstruction in 4 patients, extension by balloon catheter in one, and conservative treatment in two. Six patients have been cured and, however, one patient died of biliary cirrhosis and progressive hepatic failure at 4 years after PD. When improvement by the extension of stricture was not observed, surgical approach should be necessary. Complete resection of stricture and anastomosis between normal bile duct and intestine might be necessary. Indication of placement of metallic stent in stricture was thought to be carefully considered