Study of correlation between plasma parameter and beam optics

Simultaneous measurement of negative ion source plasma and extracted beam is carried out in order to clarify a key plasma parameter governing the meniscus formation in negative ion sources for fusion. The plasma discharge is performed with various discharge powers at different bias voltages in order to vary the plasma parameters. It is shown that the beam width changes along the same curve with respect to the negative ion density at any bias voltage while it varies along different curves with other plasma parameters depending on the bias voltage. This implies that the mechanism of meniscus formation in negative ion sources could be described along the similar manner as positive ion sources.

Spatial distribution of negative ion density near the plasma grid

Density distributions of negative hydrogen (H^-) ions and negative deuterium (D^-) ions were measured with the laser photodetachment method in the extraction region of the negative ion source. The distribution of H^- ion density peaks at the center of the ion source, while that of the D^- ion shows a flatter profile in the direction parallel to the plasma grid. The positive ion densities of hydrogen and deuterium estimated from the positive saturation current indicate similar profiles with different amounts close to the grid. The difference in the H^- ion and D^- ion distributions can be explained by the difference in the negative ion yield and the survival probability of the ions due to the isotope effect.

Extension of high power deuterium operation of negative ion based neutral beam injector in the large helical device

Second deuterium operation of the negative ion based neutral beam injector was performed in 2018 in the large helical device. The electron and ion current ratio improves to I_e/I_acc(D) = 0.31 using the short extraction gap distance of 7 mm between the plasma grid (PG) and the extraction grid (EG). The strength of the magnetic field by the electron deflection magnet installed in the EG increases by 17% at the PG ingress surface, which effectively reduces the electron component in the negative ion rich plasma in the vicinity of PG apertures. The reduction of the electron current made it possible to operate at a high power arc discharge and beam extraction. Then, the deuterium negative ion current increases to 55.4 A with the averaged current density of 233 A/m². The thermal load on the EG using 7 mm gap distance is 0.6 times smaller than the thermal load using a 8 mm gap caused by the reduction of coextracted electron current. The injection beam power increases to 2.9 MW in the beam line BL3, and the total beam injection power increases to 7 MW by three beam lines in the second deuterium campaign.

Development of a dual beamlet monitor system for negative ion beam measurements

To evaluate negative ion beam properties, a dual beamlet monitor system has been developed. The dual beamlet monitor system has two diagnostics in one hexagonal box. One diagnostic is a "fast beamlet monitor" for measuring the time evolution of beamlet current profiles with the time resolution of up to 25 MHz. The other diagnostic is a "pepper-pot-type phase space analyzer," which is applied for the evaluation of a phase space structure of the negative ion beamlet. The dual beamlet monitor system is applied to the measurement of the beamlet in the Neutral Beam Test Stand at National Institute for Fusion Science (NIFS-NBTS), in which the beam accelerator is almost identical to those of working beam injectors in the large helical device. It is demonstrated that the overlapping components from the neighboring beamlet can be eliminated, and the phase space structure can be obtained for the single beamlet.

Radiotherapy for Glioma During Pregnancy: Fetal Dose Estimates, Risk Assessment and Clinical Management

Cancer in pregnancy is relatively uncommon, but constitutes a major problem. We report the measurement of scatter dose to the fetus and the estimated fetal risk from that exposure in an illustrative case of a patient, 20 weeks pregnant, with a grade 3 anaplastic astrocytoma. A clinical decision was made to withhold radiotherapy, if possible, until after delivery. Sequential magnetic resonance imaging (MRI) showed no progression during the pregnancy. In the event, she was managed conservatively until the successful completion of her pregnancy. In case radiotherapy was required, an estimation of the fetal risk was made. Phantom measurements were undertaken to assess the likely fetal dose. Film badges were used to estimate the scattered radiation energy. Measurements were made on a Varian 600C at 6 MV and Asea Brown Boveri (ABB) accelerator at 8 and 16 MV. Doses were measured at 30, 45 and 60 cm from the isocentre; the fetus was assumed to lie at about 60 cm and not closer than 45 cm from the isocentre. Estimated doses to the position of the fetus were lowest with the 6 MV Varian accelerator. Using this machine without additional abdominal shielding, the estimated dose on the surface at 45 cm from the tumour volume was 2.2 cGy for a tumour dose of 54 Gy; using the ABB accelerator, the dose varied between 49-59 cGy. The energy of scattered radiation was in the range 208-688 keV, so that additional shielding would be practical to further reduce the fetal dose. The risk of cancer up to the age of 15 years attributable to radiation is 1 in 1700 per cGy, of which half will be fatal (i.e. 1 in 3300 per cGy). A dose of 2.2 cGy adds a risk of fatal cancer by the age 15 years of only 1 in 1500. Because the addition of shielding might halve the fetal dose, this risk should be reduced to 1 in 3000. For comparison, the overall UK risk of cancer up to the age 15 years is 1 in 650. In conclusion, careful choice of linear accelerator for the treatment of a pregnant woman and the use of additional shielding is valuable, as this can dramatically affect fetal dose.

[Mucosa-associated lymphoid tissue lymphoma; report of two cases]

Primary pulmonary malignant lymphoma is a rare disease that is thought to belong to a category of malignant lymphomas arising from mucosa-associated lymphoid tissue (MALT). We presented 2 cases of MALT lymphoma. Case 1: In a 39-year-old woman, an abnormal shadow was detected in chest radiography in the left S3. The diagnosis was organizing pneumonia in consequence of the further examination. One year after an growing abnormal shadow was detected again, we performed the tumor resection with the thoracoscopy in the possibility of malignancy. The pathological diagnosis was MALT lymphoma. Case 2: In a 70-year-old man, middle lobe syndrome was detected in chest radiography. As a result of the bronchial biopsy, the lesion was suspected of MALT lymphoma. Right middle lobectomy was performed, and the tumor was diagnosed as a MALT lymphoma histologically. He underwent an effective postoperative radiotherapy and has had no evidence of recurrence.

Thoracoscopic treatment for spontaneous hemopneumothorax

Spontaneous hemopneumothorax is a rare clinical entity sometimes requiring an operation in the early stage. Two patients who underwent successful video-assisted thoracic surgery (VATS) for spontaneous hemopneumothorax are presented. In both cases, the bleeding point was clearly identified, and hemostasis was easily obtained by clipping the point and placing three access ports in the usual fashion. Furthermore, the evacuation of clotted blood and resection of bulla were performed with no difficulties. The postoperative courses were smooth, and no complications occurred, although the preoperative general condition in the second case was hemodynamically unstable. The advantages of VATS over conventional thoracotomy include less time required to access the pleural cavity, a better view, and more facilitated manipulation during surgery. Because spontaneous hemopneumothorax is a benign disease, VATS should be considered an initial treatment option in all patients with this condition, even those with active bleeding.

[A case of ACTH-producing thymic carcinoid tumor with Cushing syndrome]

ACTH-producing thymic carcinoid tumor with Cushing syndrome in a 41-year-old male was reported. Plasma ACTH and cortisol was high, and chest X-ray film and CT scan revealed a tumor mass in the anterior mediastinum. Extended thymectomy with pretracheal lymph node dissection was performed. The microscopic findings revealed that the mass was carcinoid tumor with metastasis of anterior mediastinal lymph node. ACTH and cortisol were restored to normal range 1 week after operation. Unfortunately, he admitted seven months later because of high level of ACTH and right supraclavicular lymph nodes swelling. He underwent right neck dissection. Pathological examination proved metastatic carcinoid tumors in the dissected nodes. It is important to perform supraclavicular lymph node dissection together with extended thymectomy for thymic carcinoid tumor.

Thromboxane A2 receptor antagonist (ONO 3708) protects from liver damage induced by cholestasis and ischemia-reperfusion

The effect of a thromboxane (Tx) A2 receptor antagonist, ONO 3708, on cholestasis and injury related to ischemia and subsequent reperfusion (I-R) was investigated in the dog liver by assessing changes in insulin and glucagon metabolism. The left hepatic duct was ligated for 4 weeks to create a cholestatic lobe. Sixty-minute ischemia was induced by Pringle's procedure. ONO 3708 (200 micrograms/kg/min) was initiated 60 min before induction of ischemia and continued throughout the experiment. The rate of insulin metabolism was higher in the right noncholestatic lobe than in the left cholestatic lobe. There was no significant difference in the rate of glucagon metabolism between the right and left lobes. After induction of I-R, the rate of insulin metabolism, but not glucagon metabolism, decreased. The lipid peroxide level was higher and the glutathione level was lower in the cholestatic lobe than in the noncholestatic lobe. There was no significant difference in the alpha-tocopherol level between lobes. After induction of I-R, the lipid peroxide level increased and the alpha-tocopherol level decreased. There was no change in the glutathione level. I-R accelerated the release of 6-keto-prostaglandin (PG) F1 alpha, a stable metabolite of PGI2, and of TxB2, a stable metabolite of TxA2, from the liver. After I-R, cholestasis accelerated the release of TxB2, but not 6-keto-PGF1 alpha. I-R also increased the TxB2/6-keto-PGF1 alpha ratio. ONO 3708 reduced these metabolic changes in the cholestasis and after I-R. These findings suggest that ONO 3708 protects liver function, especially in the cholestatic lobe, from I-R-related injury by reducing peroxidation of lipids and the TxA2/PGI2 ratio, which predicts cellular damage, and by increasing levels of alpha-tocopherol and glutathione.

Protective effect of the thromboxane A2 receptor antagonist ONO 3708 on ischemia-reperfusion injury in the dog liver

BACKGROUND

Prostaglandins are widely known to have cytoprotective effects in a variety of conditions. Thromboxane A2 has the opposite effect of prostaglandins. In this study the effects of the thromboxane A2 receptor antagonist ONO 3708 on ischemia and subsequent reperfusion in the dog liver was evaluated.

METHODS

Mongrel dogs weighing from 10 to 15 kg were divided into three groups: a control group, a group with induced liver ischemia and subsequent reperfusion, and a group that received ONO 3708 and then underwent induced liver ischemia and subsequent reperfusion. Liver ischemia was induced by the Pringle procedure for 60 minutes. The concentrations of total free amino acids, aromatic amino acids, and branched-chain amino acids in blood taken from the portal and hepatic veins were examined before and after the Pringle procedure in the latter two groups and at the corresponding points in the control group.

RESULTS

Disturbances in amino acid metabolism in the liver occurred 5 minutes after the declamping in the ischemic group, and prostaglandin I2 and thromboxane A2 levels and lipid peroxide production, were increased. In contrast, hepatic amino acid metabolism was unchanged, and prostaglandin I2 and thromboxane A2, and lipid peroxide production, were normalized in the group that was treated with ONO 3708.

CONCLUSIONS

ONO 3708 appears to protects hepatic tissue from ischemia-reperfusion injury through free-radical scavenging, by increasing prostaglandin I2 levels, and by decreasing thromboxane A2 production.

Prostaglandin E1 protects liver from ischemic damage

Studies were carried out to investigate the effects of prostaglandin E1 (PGE1) pretreatment on normothermic liver ischemia. Mixed-breed dogs were divided into three groups: a control group, a group with induced liver ischemia, and a group pretreated with PGE1 followed by induced liver ischemia. Liver ischemia was induced by the Pringle procedure for 60 min. PGE1 was administered intravenously to some dogs at a dose of 0.5 microgram/kg/min for 30 min prior to the Pringle procedure. Sham operations were performed without induction of liver ischemia in control animals. Insulin, glucagon, and glucose metabolic clearance rates were examined before and after the Pringle procedure in the control and experimental groups. Insulin and glucose metabolic clearance rates decreased 5 min after declamping in the ischemic group, while the glucagon metabolism was not affected, and lipid peroxide production increased. In contrast, hepatic insulin metabolism improved, and lipid peroxide production normalized in the ischemic group which was pretreated with PGE1. This study suggests that PGE1 prevents hepatic metabolic disturbances due to warm ischemia and subsequent reperfusion.

Prostaglandin E1 protects dog pancreas from ischemia-reperfusion injury

Effects of prostaglandin (PG) E1 on ischemia-reperfusion (I-R) injury to the pancreas was evaluated using isolated in vivo perfused dog pancreas. Pancreatic endocrine and exocrine functions were stimulated with 10(-12) M cholecystokinin octapeptide (CCK-8). This amount of CCK-8 promoted production of insulin, glucagon, PGI2, and thromboxane (Tx) A2 in the pancreas. Sixty minutes of ischemia and subsequent reperfusion induced damage to pancreatic ductular, acinar, and beta cells. Intra-arterial administration of PGE1 at a dose of 0.5 microgram/kg/min throughout the experiment prevented the I-R injury, reducing plasma lipid peroxides, and elevating PGI2 without changing TxA2 in the pancreas. PGE1 thus appears to protect pancreatic function from I-R injury both by depressing the effect of free-radicals and by decreasing TxA2/PGI2 which predicts cell injury.

The effect of a thromboxane A2 receptor antagonist (ONO 3708) on ischemia-reperfusion injury of the dog pancreas

The effects of a thromboxane A2 receptor antagonist, ONO 3708, on ischemia-reperfusion injury of the pancreas were evaluated using an isolated in-vivo-perfused dog pancreas model. Pancreatic endocrine and exocrine function were stimulated with cholecystokinin octapeptide (10(-12) mol). This dose significantly increased endogenous prostaglandin I2 and thromboxane A2 production by the pancreas (both P < 0.001). A period of 60 min of ischemia and subsequent reperfusion induced an increase of pancreatic amylase release (P < 0.01) and a decrease of insulin release (P < 0.01). There was also a decrease of pancreatic juice and pancreatic bicarbonate and amylase output (au P < 0.01), suggesting damage to the acinar, ductular, and beta cells. Intravenous administration of ONO 3708 (200 micrograms/kg/min) throughout the experiment prevented these abnormalities of pancreatic secretion. It also reduced the plasma lipid peroxide level in the venous drainage (P < 0.01) and elevated the prostaglandin I2 level (P < 0.01) without changing thromboxane A2 levels. ONO 3708 thus appeared to protect the pancreas from ischemia-reperfusion injury by reducing the peroxidation of cell membrane lipids and by decreasing the thromboxane A2/prostaglandin I2 ratio, which is a predictor of cellular injury.

Effects of parathyroid hormone on pancreatic exocrine secretion

The role of parathyroid hormone (PTH) and calcium on pancreatic exocrine secretion were observed using sham-operated and parathyroidectomized dogs. First, exocrine secretion of the pancreas stimulated with secretin and cholecystokinin octapeptide (CCK-8) was examined in vivo 3 weeks after parathyroidectomy. Secondly, perfusion experiments of isolated pancreas in the sham-operated and parathyroidectomized dogs were examined. In one experiment, volume of pancreatic juice and bicarbonate output, but not amylase output, was decreased in the parathyroidectomized dogs compared with those in the sham-operated dogs; no participation of calcium in exocrine secretion was revealed. In another experiment, high doses of PTH evoked increases of pancreatic juice and bicarbonate output without changing amylase output; as before, no participation of calcium in the exocrine secretion was observed. We conclude that (a) PTH increases volume of pancreatic juice and bicarbonate output, and (b) pancreatic exocrine secretion is modified by direct effect of PTH, and the pancreatic ductular cells, not the acinar cells, are the target for PTH.

Enhanced sensitivity of pancreatic cells to cholecystokinin octapeptide in obstructive jaundice

Exocrine function of the pancreas in obstructive jaundice was examined using dogs. Jaundice induced by choledochal ligation over 3 weeks showed pancreatic hypersecretion in response to cholecystokinin octapeptide (CCK-8) stimulation. To clarify the mechanism of pancreatic hypersecretion in obstructive jaundice, three experiments were undertaken. In a perfusion experiment performed on isolated pancreas, hypersecretion in obstructive jaundice was observed in response to CCK-8 stimulation. An incubation experiment showed an increase in secretion in response to CCK-8 stimulation in a dose-dependent manner, producing a greater increase in dogs with obstructive jaundice than in controls, despite the fact that basal secretion in both groups was the same. This would suggest that at least one of the mechanisms of pancreatic hypersecretion in obstructive jaundice may be related to the degree of sensitivity of acinar cells to CCK-8. In morphological observation of acinar cells by electron microscopy, the average number of zymogen granules and total granular area per unit of cytoplasm in both groups before and after stimulation with CCK-8 were compared. There was no difference between the groups before stimulation. Following stimulation, values for the control group decreased but appeared to increase in the jaundiced pancreas. These results strongly suggest that pancreatic acinar cells in obstructive jaundice may retain their secretory potential after stimulation for 60 min, though the potential in nonjaundiced pancreatic acinar cells may decrease after stimulation.

Metabolism of insulin and glucagon in liver and pancreas in dogs with obstructive jaundice

Insulin and glucagon metabolism in the pancreas with obstructive jaundice caused by complete ligation of the common bile duct and in the cholestatic liver caused by hepatic duct ligation was evaluated experimentally using dogs. The isolated perfused pancreas in obstructive jaundiced dogs, which showed a low insulin response in the peripheral blood after intravenous glucose administration, revealed depression of insulin production and no change of glucagon production in response to cholecystokinin octapeptide. The extraction of insulin in the cholestatic lobe of the liver was decreased compared with that in the noncholestatic lobe. The extraction of glucagon, on the other hand, in the cholestatic lobe and in the noncholestatic lobe showed no significant difference. So the imbalance of glucose metabolism in obstructive jaundice does not depend on the enhanced extraction of insulin in the liver, but on the depression of insulin production in the pancreas.

Gas-forming liver abscess after transcatheter arterial embolization for hepatocellular carcinoma: report of a case

A case of a gas-forming liver abscess developing after transcatheter arterial embolization for recurrent hepatocellular carcinoma (HCC) in a 65-year-old man is presented herein. He was admitted to hospital with fever and jaundice, following which ultrasonography (US) and computed tomography revealed a gas-containing abscess in the posterior segment of the hepatic lobe with multiple HCC. Percutaneous transhepatic drainage was performed using US. Antibiotics which were sensitive to the Escherichia coli bacteria detected in the abscess were administered both intravenously and through the drainage tube into the abscess. Four months later, the abscess had diminished and the patient was discharged after receiving percutaneous ultrasonographically guided ethanol injection therapy for the recurrent HCC.

[Treatment of liver metastases from gastric cancer]

Nine patients with liver metastases from gastric cancer were treated in our department since 1986. Hepatectomy was performed in 3 cases and hepatic arterial infusion chemotherapy was performed in 6 cases. In 3 patients in whom hepatectomy was performed, the extent of liver metastases showed 2 H1 and 1 H2. One has survived for 20 months, but the other 2 died after 5 and 7 months, respectively. In 6 patients in whom hepatic arterial infusion chemotherapy was performed, the extent of liver metastases was H3. These patients were treated with 5-FU.EPIR.MMC (3 cases), CDDP.MMC (1 case), MMC only (1 case) and 5-FU.ADM.MMC.CDDP (1 case). This treatment revealed a 50% response rate (CR 1, PR 2). The patient with CR has survived for 6 years and 2 patients with PR died after 8 and 12 months. The patient with CR showed high AFP level (55, 480 ng/ml), and 2 patients with PR showed high AFP level (24, 327 ng/ml) or high CEA level (3,903 ng/ml). The prognosis of hepatectomy for liver metastases from gastric cancer was not so good. Hepatic arterial infusion chemotherapy seemed to be a useful treatment for liver metastases from gastric cancer.

Two cases of acute pseudogout attack following parathyroidectomy

Two cases of acute attack of pseudogout associated with primary hyperparathyroidism are reported. Case 1 suffered from acute pain and swelling of the right ankle and dorsal of the right foot. Case 2 suffered from unknown fever and pain of the bilateral jaw, shoulder, elbow, wrist and knee joints. Postoperative radiological studies revealed the association of chondrocalcinosis in both cases. Synovial fluid in case 2 was aspirated and analyzed for calcium pyrophosphate dihydrate crystal by microscopic examination.

[A case of quadruple cancer composed of the breast, kidney, liver and uterus carcinomas]

A case of quadruple cancer is reported. A 74-year-old female was admitted because of surgery for left breast cancer. Abdominal echography showed a mosaic patterned mass of the liver and a solid tumor with central necrosis at the left kidney. Echographic diagnosis was hepatoma and Grawitz's tumor. All the tumors were justified as being operable. Progressive cystorrhagia which was due to radiation cystitis after radiotherapy for uterine carcinoma could not be controlled. Autopsy diagnosis was a quadruple carcinoma composed of solid tubular carcinoma of left breast, left renal carcinoma, hepatocellular carcinoma and squamous cell carcinoma of the uterus.