Calculation of personal dose equivalent for positron-emitting radionuclides using Monte Carlo code EGS5

The conversion coefficients, H'(d,α)/Φ, for monoenergetic positrons and positron-emitting radionuclides were calculated by using the user code UCICRPM of the Monte Carlo code EGS5 to estimate the radiation dose for medical staff involved in positron emission tomography examinations. From these coefficients, the dose equivalent rates per unit activity at 0.07 and 10 mm depths in a soft tissue for a straight-line source of 2-deoxy-2-[(18)F]fluoro-d-glucose ((18)F-FDG) were calculated by using the developed user code UCF18DOSE. The dose equivalent rates per unit activity at 0.07 and 10 mm depths were measured by using a personal dosemeter (DOSE(3)) under the same conditions as those considered in the calculation. The calculated dose equivalent rates per unit activity at 0.07 and 10 mm depths were 0.116 and 0.0352 pSv min(-1) Bq(-1), respectively, at 20 cm from the (18)F-FDG injection tube.

Measurement of radon concentration in water using the portable radon survey meter

A measurement method for measuring radon in water using the portable radon survey meter (RnSM) was developed. The container with propeller was used to stir the water samples and release radon from the water into the air in a sample box of the RnSM. In this method, the measurement of error would be <20 %, when the radon concentration in the mineral water was >20 Bq l(-1).

[A case of synchronous multiple liver metastasis of sigmoid colon cancer with a pathological complete response to combination chemotherapy of 5-FU/LV and bevacizumab]

A 73-year-old man was referred to our hospital with sigmoid colon cancer in July 2009. CT and MRI showed synchronous multiple liver metastasis. After a sigmoid colon resection in August, he received convergent chemotherapy in combination with 5-fluorouracil(5-FU)/Leucovorin(LV)(RPMI regimen)and bevacizumab for liver metastasis. After two courses without any major adverse effects, liver metastasis remarkably reduced on CT and MRI examination. We thus performed a liver resection, and pathological examination revealed a complete response in liver. Combination chemotherapy of 5-FU/LV and bevacizumab can be expected to provide safe and effective treatment for liver metastasis of colon cancer.

Outcome of liver transplantation for haemophilia

BACKGROUND

Prior to routine screening of blood products many patients with haemophilia were infected with hepatitis C virus (HCV) and have subsequently gone on to develop end-stage liver disease (ESLD).

PATIENTS AND METHODS

We report our experience of liver transplantation (LT) in patients with haemophilia that developed ESLD secondary to HCV. Patients transplanted from 1994 to 2008 were identified retrospectively. Patient demographics pre-, intra- and post-operative details and outcome were documented.

RESULTS

A total of 3800 LT were performed of which 13 had haemophilia A, 4 haemophilia B and one factor (F)X deficiency. All patients were male with a median age of 52 years (range 26-59), all were HCV antibody positive, 5 (28%) were human immunodeficiency virus (HIV) positive and 4 (22%) had hepatocellular carcinoma. Median intra-operative blood loss was 4.2 l (range 0.8-12) and all received coagulation factor support peri-operatively. Coagulation was unsupported by 72 h post-operatively in all recipients. Two patients developed complications as a result of post-operative bleeding. At a median follow-up of 90 months, 8 patients have died, including 4 of the 5 patients that were HIV positive. The median survival of patients with and without HIV co-infection was 26 and 118 months, respectively.

CONCLUSION

LT in patients with haemophilia cures the coagulation disorder and in the absence of HIV/HCV co-infection is associated with long-term patient survival.

Intracellular calcium elevation induced by extracellular application of cyclic-ADP-ribose or oxytocin is temperature-sensitive in rodent NG108-15 neuronal cells with or without exogenous expression of human oxytocin receptors

ADP-ribosyl cyclase and/or CD38 are activated after oxytocin receptor stimulation in the hypothalamus and pituitary in adult mice, leading to facilitation of oxytocin secretion. Although cyclic adenosine 5'-diphosphoribose (cADPR) primarily acts as an intracellular second messenger, it has been suggested that extracellular cADPR stimulates intracellular ryanodine receptors after internalisation via the nucleotide-transporting capacity of CD38 in fibroblasts and astrocytes. However, little is known about whether extracellular cADPR activates neurones. To address this question, we used a model neuronal cell line, NG108-15 mouse neuroblastoma x rat glioma hybrid cells possessing CD38 but not oxytocin receptors, and measured cytosolic free calcium concentrations ([Ca(2+)](i)). Extracellular application of cADPR to NG108-15 cells elevated [Ca(2+)](i) at 35 degrees C. The elevation was significantly enhanced when measured at 40 degrees C. The cADPR and heat-induced [Ca(2+)](i) increase were blocked under extracellular Ca(2+)-free conditions and by 2-aminoethoxydiphenyl borate, an antagonist of melastatin-related transient receptor potential channel 2 (TRPM2) cation channels. Reverse transcriptation-polymerase chain reaction analyses indicated that TRPM2 channels were expressed in NG108-15 cells. Application of oxytocin elevated [Ca(2+)](i) in NG108-15 cells transformed to transiently express cloned human oxytocin receptors. The oxytocin-induced [Ca(2+)](i) response was also enhanced by heat. These results indicate that the extracellular application of cADPR, together with heat, activates cation influx downstream of oxytocin receptor signalling in NG108-15 neuronal cells, and suggest the possible involvement of TRPM2 channels in oxytocin release in the mammalian brain.

Androgen receptor of the frog Rana rugosa: molecular cloning and its characterization

The androgen receptor(AR) gene is located on the Z and W sex chromosomes in the frog Rana rugosa, designated Z- and W-AR, respectively. Among various tissues of an adult frog, AR expression levels were highest in the testis and brain. In the testis, AR was expressed in germ cells. AR expression occured in developing embryos from stage 21 and was very high in the gonad of a male tadpole before the onset of sex determination. When Z- and W-AR were expressed in Xenopus A6 cells, they activated androgen-dependent transcription of a luciferase reporter gene. By contrast, estrogen receptor (ER) alpha and beta showed no sexually dimorphic expression during sex determination, but their expressions became much higher in the gonad of a female tadpole after sex determination. In addition, AR transcripts in the ZZ-tadpoles were twice as abundant as in the ZW genotype. In contrast, W-AR expression was extremely low although when W-AR was expressed in A6 cells, it activated transcription in the luciferase assay. In this regard it is worth noting that the promoter regions of Z- and W-AR are not identical. The results suggest that Z-AR plays an important role in the testis formation in a R. rugosa tadpole, whereas ERbeta is involved in ovary differentiation. Very low expression of W-AR may be due to its promoter region having mutations in key transcription factor binding sites, although these remain to be identified. Thus, it is proposed that AR could be a candidate for a male-determining gene in R. rugosa.

[Coronary artery aneurysm with various clinical course]

Case 1: A 77-year-old woman had effort angina pectoris. Coronary angiography (CAG) revealed a coronary artery aneurysm on the left descending artery. Coronary artery bypass grafting (CABG) and patch angioplasty for the aneurysm were performed. Case 2 : A 69-year-old woman had effort dyspnea CAG showed dilation of the left main trunk and beaded aneurysms (maximum 6 cm in diameter) behind the ascending aorta with a fistula to the right atrium. We closed the fistula and performed CABG to the circumflex branch. Case 3 : A 78-year-old woman had had general fatigue for 2 weeks. Previous CAG had revealed coronary artery aneurysms and current chest computered tomography revealed pericardial effusion. She was, therefore, diagnosed with the rupture of the coronary artery aneurysm. We closed the coronary artery aneurysm and performed CABG. Case 4: A 55-year-old man had been diagnosed with acute myocardial infarction and had undergone percutaneous coronary intervention 3 years before. CAG revealed a coronary artery aneurysm on the right coronary artery. We resected the aneurysm and interposed with saphenous vein graft. Although coronary artery aneurysm often has no symptoms, in the cases of angina, myocardial infarction, rupture or large aneurysm more than 3 times larger than the normal diameter, surgical repair should be considered.

[Preservation of aortic root with severe destruction in Stanford type A acute aortic dissection]

From November 1999 to December 2008, 197 patients with Stanford type A acute aortic dissection underwent the surgical treatment on an emergency basis. In 19 cases, we preserved the severely destroyed aortic root using gelatin-resorcin-formalin (GRF) glue avoiding aortic root replacement. We examined the indication and limitation of repair of the destroyed aortic root. The 19 patients were classified into 3 groups (A, B and C). Group A consisted of 7 patients who had no aortic regurgitation (AR). Group B consisted of 6 patients who had moderate to severe AR. Group C consisted of 6 patients who had coronary involvement. We preserved the broken aortic root in group A and group B. But it seemed to be rather difficult to repair the destroyed aortic root in some cases of group C.

Functional difference of receptor-type protein tyrosine phosphatase zeta/beta isoforms in neurogenesis of hippocampal neurons

Receptor-type protein tyrosine phosphatase zeta/beta (RPTPzeta) is a transmembrane chondroitin sulfate proteoglycan (CSPG) and has been shown to play crucial roles in controlling axonal growth and neuronal migration. The RPTPzeta has two transmembranous isoforms, shorter receptor form of RPTPzeta (sRPTPzeta) and full-length receptor form of RPTPzeta (fRPTPzeta), but no studies have been reported about functional difference of these two isoforms. In the present study, therefore, we examined whether or not two RPTPzeta isoforms have different role in controlling dendritic morphology and synaptic number in cultured hippocampal neurons using the quantitative morphometrical analysis. Confocal microscopic observation showed that the immunoreactivity of RPTPzeta was observed throughout cells such as axons, growth cones, and dendrites at the early stages of neuronal culture, while it was seen predominantly on dendrites at the late stages. Western blotting analysis revealed that fRPTPzeta was mainly expressed at the early stages of culture and both RPTPzeta isoforms were expressed at late stages of culture. The overexpression of sRPTPzeta in hippocampal neurons increased the dendritic arborization without altering the average length of dendritic branches, whereas that of fRPTPzeta decreased the dendritic arborization and increased the average length of dendritic branches. The RNA interference of fRPTPzeta expression increased the dendritic arborization without altering the average length of dendritic branches. The overexpression of fRPTPzeta decreased the density of hippocampal dendritic synapses, but that of sRPTPzeta had no effects. Pleiotrophin, a ligand for RPTPzeta to interfere the phosphatase activity, increased the density of hippocampal dendritic synapses. Thus, the present study demonstrates that two transmembranous RPTPzeta isoforms have different functions for regulating dendritogenesis and synaptogenesis.

[Two cases of advanced colorectal cancer with UGT1A1*28 homozygosity treated by FOLFIRI]

Severe neutropenia attributable to irinotecan hydrochloride (CPT-11) is reportedly associated with gene polymorphism of UGT1A1 related to its metabolism. Case 1 is a 70-year-old male patient with rectal cancer that had spread to the liver. Although he received six courses of mFOLFOX6, his hepatic metastasis recurred. Therefore, the regimen was switched to FOLFIRI. The CPT-11 dosage was 150 mg/m(2). Twelve days after the first course was attempted, neutropenia at grade 4 and a fever of 39 degrees C were found. Case 2 is a 65-year-old male whose sigmoid colon cancer had spread to the liver. We started FOLFIRI with a CPT-11 dosage of 120 mg/m(2). Nine days following administration of the first course, we found neutropenia of grade 3 and a fever of 38 degrees C. Analysis of the UGT1A1 gene polymorphism after symptom improvement revealed UGT1A1(*)28 homozygosity in both cases, which suggests that when FOLFIRI is conducted on a patient with homozygous UGT1A1(*)28, it is necessary to pay attention to neutropenia even with a CPT-11 dosage of 120 mg/m(2).

Living donor liver transplantation with hyperreduced left lateral segments

Liver transplantation is now an established technique to treat children with end-stage liver disease. Implantation of left lateral segment grafts (Couidaud's segments II and III) can be a problem in small infants because of a large-for-size graft. Reduced left lateral segmental liver transplantation has been recently introduced for small infants to mitigate the problem of large-for-size graft. Further reduction of the left lateral segment graft increases the possibility of supplying an adequate hyperreduced left lateral segment graft as an alternative surgical technique. We report 3 cases of our experience of transplantation using hyperreduced left lateral segment grafts from living donors.

Steroidogenic gene expression during sex determination in the frog Rana rugosa

Rana rugosa is unique among frog species in that it has two distinct types of sex chromosomes in two separate forms (XX/XY and ZZ/ZW). Treatment with sex steroids can reverse its gender from female to male or male to female. This phenomenon makes it a novel model for studying gonadal differentiation. The physiological role of sex steroids in sex differentiation in amphibians is yet unclear, however. To address this issue, we cloned the cDNAs of 17betaHSD types 8 (17betaHSD8) and 12 (17betaHSD12), 5alpha-reductase type 1 (5alphaRed1), and the steroidogenic acute regulatory protein known as StAR in the steroidogenic pathway. Then, we measured the mRNA levels of these genes during sex differentiation by real-time RT-PCR. The levels of CYP11A1, 3betaHSD, CYP17 and CYP19 mRNA were also measured by real-time RT-PCR. As a result, we detected transcripts of all such genes except for that of 17betaHSD8 in the indifferent gonad before the onset of sex determination. The expression of CYP17 occurred in indifferent gonads in both sexes; and its transcript levels were much higher in the male gonads. By contrast, the levels for CYP19 were much higher in the female gonads. CYP11A1, 3betaHSD, 17betaHSD12, 5alphaRed1 and StAR showed no sexually dimorphic expression during gonadal sex differentiation. Taken together, the results suggest that CYP17 has a major influence on testis development and that CYP19 plays a similar role in ovary development. However, the factors that up-regulate their expression remain to be identified.

Ratio of tritiated water and hydrogen generated in mercury through a nuclear reaction

Tritium generated in a mercury target is a source of potential exposure of personnel at high-energy accelerator facilities. Knowledge of the chemical form of tritium is necessary to estimate the internal doses. We studied the tritium generation upon thermal neutron irradiation of a mercury target modified into liquid lithium amalgam to examine the ratio of tritiated water ([3H]H2O) and tritiated hydrogen ([3H]H2). The ratio between [3H]H2O and [3H]H2 generated in lithium amalgam was 4:6 under these experimental conditions.

[Off-pump coronary artery bypass and right ventricular branch translocation for coronary aneurysm; report of a case]

The successful surgical treatment for a coronary artery aneurysm was reported. A 38-year-old female presented with angina pectoris due to right coronary artery stenosis. Angiography revealed a right coronary artery aneurysm and 90% stenosis at a site just proximal to the aneurysm, accompanied by the relatively large right ventricular (RV) branch originating from a mid portion of the aneurysm. Off-pump coronary artery bypass grafting (CABG) to the right coronary artery (RCA) #3, translocation of RV branch to RCA #3, and ligation of RCA proximal and distal to the aneurysm were successfully performed. Post-operative course had been uneventful with satisfactory angiographic results. Coronary translocation with CABG could be a treatment option for coronary artery aneurysms.

Efficacy of living donor liver transplantation for patients with methylmalonic acidemia

Application of liver transplantation to methylmalonic acidemia (MMAemia) is controversial because MMAemia is caused by a systemic defect of methylmalonyl-CoA mutase. The clinical courses of seven pediatric patients with MMAemia undergoing living donor liver transplantation (LDLT) were reviewed. Serum and urinary methylmalonic acid (MMA) levels were found to be significantly decreased after LDLT, whereas serum and urinary MMA levels did not return to normal in any patient. One patient died of sepsis 44 days after LDLT. The other six patients are currently doing well. All patients had preoperative history of acute metabolic decompensation and/or metabolic stroke. However, no episode of acute metabolic decompensation or metabolic stroke was observed postoperatively in any surviving patients. In the preoperative period, all patients showed lethargy and cognitive deficit, both of which were eradicated after LDLT in all surviving patients. Preoperatively, all patients were subjected to dietary protein intake restriction and tube feeding, and were administered several metabolism-correcting medications. The metabolism-correcting medications being administered remained mostly unchanged after LDLT, whereas protein restriction was liberalized and tube feeding became unnecessary in all surviving patients. In addition, physical and neurodevelopmental growth delay remained in all surviving patients during the observation period, which ranged from 4 to 21 months with a median of 10.5 months.

Ratio of aerosol and gases of radioactive chlorine and particle size distribution of aerosol formed by high-energy proton irradiation

To estimate internal doses due to the inhalation of radionuclides produced by the nuclear spallation of the air nuclei in high-energy proton accelerator facilities, the physicochemical properties of radionuclides are very important. Thus, the ratio of aerosol and gases of 38Cl and 39Cl formed by irradiating argon gas-added air with a 48 MeV proton beam has been measured. Radionuclides of 38Cl and 39Cl exist as aerosol, acid gas and non-acid gas. The percentages of activity of 38Cl and 39Cl aerosols are about 80%. The number size distributions of non-radioactive aerosol were characterised by two peaks with diameters of 10-20 nm and larger than 20 nm. As a result predicted by a simple surface model, it was found that the activity size distribution of 38Cl aerosols can be regarded as that having a single peak at 120 nm.

Identification and characterization of Asef2, a guanine-nucleotide exchange factor specific for Rac1 and Cdc42

The tumor suppressor adenomatous polyposis coli (APC) is mutated in sporadic and familial colorectal tumors. APC interacts with the Rac1-specific guanine-nucleotide exchange factor (GEF) Asef, which contains an APC-binding region (ABR) in addition to Dbl homology (DH), Pleckstrin (PH) and Src homology 3 (SH3) domains. APC stimulates the GEF activity of Asef, and thereby regulates cell adhesion and migration. Here, we have identified a second Asef, termed Asef2, that shows significant structural and functional similarities to Asef. We found that both the N-terminal ABR and SH3 domains of Asef2 are responsible for its interaction with APC. When expressed in HeLa cells, a mutant Asef2 lacking the ABR and SH3 domains, Asef2-DeltaABR/SH3, induced increases in the levels of the active forms of Rac1 and Cdc42. Full-length Asef2 also showed this activity when co-transfected with truncated mutant APC expressed in colorectal tumor cells. Consistent with this, either Asef2-DeltaABR/SH3 or Asef2 plus truncated mutant APC stimulated lamellipodia formation in MDCK cells and filopodia formation in HeLa cells. Furthermore, RNA interference experiments showed that Asef2 is required for migration of colorectal tumor cells expressing truncated APC. These results suggest that similar to Asef, Asef2 plays an important role in cell migration, and that Asef2 activated by truncated mutant APC is required for aberrant migration of colorectal tumor cells.