High-intensity laser-accelerated ion beam produced from cryogenic micro-jet target.

We report on the successful operation of a newly developed cryogenic jet target at high intensity laser-irradiation. Using the frequency-doubled Titan short pulse laser system at Jupiter Laser Facility, Lawrence Livermore National Laboratory, we demonstrate the generation of a pure proton beam a with maximum energy of 2 MeV. Furthermore, we record a quasi-monoenergetic peak at 1.1 MeV in the proton spectrum emitted in the laser forward direction suggesting an alternative acceleration mechanism. Using a solid-density mixed hydrogen-deuterium target, we are also able to produce pure proton-deuteron ion beams. With its high purity, limited size, near-critical density, and high-repetition rate capability, this target is promising for future applications.

Absolute dosimetric characterization of Gafchromic EBT3 and HDv2 films using commercial flat-bed scanners and evaluation of the scanner response function variability.

Radiochromic films (RCF) are commonly used in dosimetry for a wide range of radiation sources (electrons, protons, and photons) for medical, industrial, and scientific applications. They are multi-layered, which includes plastic substrate layers and sensitive layers that incorporate a radiation-sensitive dye. Quantitative dose can be retrieved by digitizing the film, provided that a prior calibration exists. Here, to calibrate the newly developed EBT3 and HDv2 RCFs from Gafchromic™, we used the Stanford Medical LINAC to deposit in the films various doses of 10 MeV photons, and by scanning the films using three independent EPSON Precision 2450 scanners, three independent EPSON V750 scanners, and two independent EPSON 11000XL scanners. The films were scanned in separate RGB channels, as well as in black and white, and film orientation was varied. We found that the green channel of the RGB scan and the grayscale channel are in fact quite consistent over the different models of the scanner, although this comes at the cost of a reduction in sensitivity (by a factor ∼2.5 compared to the red channel). To allow any user to extend the absolute calibration reported here to any other scanner, we furthermore provide a calibration curve of the EPSON 2450 scanner based on absolutely calibrated, commercially available, optical density filters.

[Methods of intraductal pancreatic hypertension elimination].

The study is devoted to the surgical treatment of benign pancreatic cysts. Results of the internal drainage of pancreatic duct ul system in 76 patients were analyzed. Pancreaticoenterostomy combined with partial pancreatic resection in 21 cases, was performed in 53 patients. The rest 23 patients required no enterostomy of the main pancreatic duct. The lateral pancreaticojejunostomy was performed in 48 patients, of whom 32 patients had an original reconstructive circulation of the intestinal loop applied. By the width of the pancreatic duct less then 5 mm, the original method of resection of the front surface of the pancreas was applied (n=5). The bilateral pancreaticojejunostomy was performed in 3 patients with the pancreatic duct width less then 5 mm and diastasis of the latter. There was no postoperative lethality; complicated postoperative period required reoperation in 5,3%. Long-term results were considered good in 74,6%, satisfactory in 16,4% and unsatisfactory in 9% of patients.

[An original method of the recovery period after medial resection of the pancreas].

A method of rehabilitating stage after medial resection of the pancreas was developed with the width of the main pancreatic duct from 3 to 5 mm, allowing widening the area of the anastomozing surface. The method was used in practice with good nearest results.

[Clinical parallels of computer tomography and intraoperative findings in benign cystic formations of the pancreas].

A comparative analysis was made of preoperative computer diagnostics and intraoperative findings in 151 patients operated at various periods of chronic pancreatitis (CP) (n=76) with exacerbation of pancreatitis (or relapsed acute against the background of chronic) and 75 patients without exacerbation. Ninety (59.6%) patients have arrived with complications. Sensitivity of the method of computer tomography in patients with pancreatic exacerbation is 97.4%, without exacerbation is 98.7%. Dilatation of the main pancreatic duct is divided into three degrees. The dilatation of the 2nd and 3d degrees was diagnosed in 78 patients. All the patients were operated on the pancreas in the volume of direct interventions including external drainage which was performed in 69, internal in 56, separately resectional operations in 19, isolated cystectomy in 7 patients, In the group of patients operated out of exacerbation a correlation between the degree of the internal pancreas duct hypertension according to the data of preoperative computed diagnostics and the number of operations of internal drainage was followed. The presence of pancreatitis exacerbation (or relapsed acute against the background of chronic) in 27.5% (n=21) did not allow lateral pancreaticojejunostomy to be performed. In 23 patients the presence of exacerbation, complications of CP due to proper cystic formation (suppuration) and from adjoining organs was not considered contraindication to longitudinal and bilateral pancreaticojejunostomy. Low indices of postoperative lethality (0.7%) and of the number of postoperative complications (6%) confirmed the possibility to liquidate intraductal hypertension in complicated CP at earlier terms that protects the patients from many stages of surgical treatment.

[Method of pancreaticoduodenal resection].

Immediate results of 59 pancreaticoduodenal resections for cancer of the pancreas and 7 - for chronic pancreatitis were analyzed. An original method of pancreaticoduodenal resection was developed consisting in optimization of the recovery phase by making a pancreatogastroanastomosis on the posterior wall of the stomach, subsequent pancreatojejunostomy and then gastrojejunostomy with the gastric stump and circularly enteroenteroanastomosis closed loop of the small intestine with disconnection of them by the machine stitch. Using the new technique operations were performed on 12 patients without complications although total postoperative lethality due to incompetence of the pancreaticodigestive anatomoses after PDR was 6%.

[Prophylactics of acute pancreatitis in pancreatic-duodenal resection]. / Profilaktika ostrogo pankreatita pri pankreatoduodenal'noi rezektsii.

Results of pancreatoduodenal resections were analyzed in 124 patients. All the patients were divided into 3 groups. The most common complication of pancreatoduodenal resections were shown to be postoperative pancreatitis resulting in incompetence of the pancreatodigestive anastomosis. The patients of the first group received traditional therapy. In the patients of the third group the application of a combined medicamentous prophylactics with Sandostatin and Verapanil allows the incidence of postoperative pancreatitis to be decreased from 35.4% noted in the first group to 18.4%.

[Informative value of various methods of intraoperative biopsy of the pancreatic head]. / Informativnost' razlichnykh metodov intraoperatsionnoi biopsii golovki podzheludochnoi zhelezy.

A comparative estimation of different methods of biopsy of the pancreatic head performed during operation on 192 patients with indurative diseases and cancer of the pancreatic head was made. The results of these investigations were compared with clinical and diagnostic findings before operation and with long-term results of the treatment. Two-lumen thick needle biopsy (the needle diameter 2 mm) of the pancreatic head proved to be most informative. In spite of the relatively high informative value of this method in cases of pseudotumorous pancreatitis (92%) the possibility of pancreatic head cancer is thought to be still underestimated in all diagnostic steps including the pre- and intraoperative stages.

In vitro metabolism of 19-nor-1alpha, 25-(OH)2D2 in cultured cell lines: inducible synthesis of lipid- and water-soluble metabolites.

The active vitamin D analog, 19-nor-1alpha,25-dihydroxyvitamin D2 (19-nor-1alpha,25-(OH)2D2), has a similar structure to the natural vitamin D hormone, 1a,25-dihydroxyvitamin D3 (1alpha,25-(OH)2D3), but lacks the C10-19 methylene group and possesses an ergosterol/ vitamin D2 rather than a cholesterol/vitamin D3 side chain. We have used this analog to investigate whether any of these structural features has any effect upon the type and rate of in vitro metabolism observed. Using a vitamin D-target cell, the human keratinocyte, HPK1A-ras, we observed formation of a number of metabolites, three of which were purified by extensive HPLC and conclusively identified by a combination of GC-MS and chemical derivatization as 19-nor-1alpha,24,25-(OH) 3D2, 19-nor-1alpha,24,25,26-(OH) 4D2, and 19-nor-1alpha,24,25,28-(OH)4,D2. The first metabolite is probably a product of the vitamin D-inducible cytochrome P450, P450cc24 (CYP24), while the latter two metabolites are likely to be further metabolic products of 19-nor-1alpha,24,25-(OH)3D2. These hydroxylated metabolites resemble those identified by other workers as products of the metabolism of 1alpha,25-(OH)2D2 in the perfused rat kidney. It therefore appears from the similar metabolic fate of 19-nor-1alpha,25-(OH)2D2 and 1alpha,25-(OH)2D2 that the lack of the C10-19 methylene group has little effect upon the nature of the lipid-soluble metabolic products and the rate of formation of these products seems to be comparable to that of products of 1alpha,25-(OH)2D3 in vitamin D-target cells. We also found extensive metabolism of 19-nor-1alpha,25(OH)2D2 to water-soluble metabolites in HPK1A-ras, metabolites which remain unidentified at this time. When we incubated 19-nor-1alpha,25-(OH)2D2 with the liver cell line HepG2, we obtained only 19-nor-1alpha,24,25-(OH)3D2. We conclude that 19-nor-1alpha,25-(OH)2D2 is efficiently metabolized by both vitamin D-target cells and liver cells.

[An analysis of the immunity indices of patients with indurative diseases of the head of the pancreas]. / Analiz pokazatelei immuniteta u bol'nykh s indurativnymi zabolevaniiami golovki podzheludochnoi zhelezy.

Based on an analysis of dynamics of immunity indices the authors have revealed differences in the character of their changes in nontumoral and tumoral diseases and in relation to the stage of the malignant process. The optimal minimum of indices of the immunity status in indurative diseases of the pancreas head is proposed which is of significance for differential diagnosis and determination of resectability of the tumor.

[Pancreaticoduodenal resections "at the height" of profuse hemorrhage from a tumor]. / Pankreatoduodenal'nye rezektsii "na vysote" profuznogo krovotecheniia iz opukholi.

The authors share their experiences with observations of profuse bleedings from the tumour of the pancreas head into the duodenum lumen. The clinical picture of this complication and surgical methods of treatment are described. Both patients recovered.