Decreased expression of haemoglobin beta (HBB) gene in anaplastic thyroid cancer and recovery of its expression inhibits cell growth.

Anaplastic thyroid cancer (ATC) is one of the most fulminant and foetal diseases in human malignancies. However, the genetic alterations and carcinogenic mechanisms of ATC are still unclear. Recently, we investigated the gene expression profile of 11 anaplastic thyroid cancer cell lines (ACL) and significant decreased expression of haemoglobin beta (HBB) gene in ACL. Haemoglobin beta is located at 11p15.5, where loss of heterozygosity (LOH) was reported in various kinds of cancers, including ATC, and it has been suggested that novel tumour suppressor genes might exist in this region. In order to clarify the meaning of decreased expression of HBB in ATC, the expression status of HBB was investigated with ACL, ATC, papillary thyroid cancer (PTC) and normal human tissues. Haemoglobin beta showed significant decreased expression in ACLs and ATCs; however, in PTC, HBB expressed equal to the normal thyroid gland. In addition, HBB expressed in normal human tissues ubiquitously. To validate the tumour-suppressor function of HBB, cell growth assay was performed. Forced expression of HBB in KTA2 cell, which is a kind of ACL, significantly suppressed KTA2 growth. The mechanism of downregulation of HBB in ATC is still unclear; however, our results suggested the possibility of HBB as a novel tumour-suppressor gene.

Comprehensive gene expression profiling of anaplastic thyroid cancers with cDNA microarray of 25 344 genes.

Little is known about the genetic mechanisms of anaplastic thyroid cancer (ATC). This is the most virulent of all human malignancies, and it is believed to result from transformation of differentiated thyroid cancers. To identify a set of genes involved in the development of ATC, we investigated expression profiles of 11 cell lines derived from ATC using a cDNA microarray representing 25 344 genes. Semi-quantitative RT-PCR experiments carried out for some genes that had shown altered expression on the microarray verified frequent over-expression of destrin, HSPA8, stathmin, LDH-A, ATP5A1, PSMB6, B23, HDP-1 and LDH-B, and frequent under-expression of thyroglobulin, PBP and c-FES/FPS genes among the cell lines and also among ten primary ATCs. In addition to mRNA expression studies, up-regulation of GDI2, destrin and stathmin were confirmed with immunohistochemical analysis. The extensive list of genes identified provides valuable information towards understanding the development of ATC, and provides a source of possible biomarkers for diagnosis and/or molecular targets for the development of novel drugs to treat ATC.

Combined system of synchrotron radiation and laser for solid-state research.

Two combined systems of synchrotron radiation and laser have been constructed for solid-state research. One is a laser-induced fluorescence system to observe synchrotron radiation-induced desorption of alkali atoms from ionic crystals, which consists of a laser diode with a high repetition rate and synchrotron radiation under a single-bunch operation. The other is a system of two-photon spectroscopy, which is based on the combination of synchrotron radiation pulses with a low intensity and high repetition rate and Nd:YAG laser pulses with a high intensity and low repetition rate. The experimental systems and the preliminary results are presented in this report.

Pheochromocytoma in a long-term hemodialysis patient, discovered as an adrenal incidentaloma.

A case of pheochromocytoma was discovered incidentally during long-term hemodialysis for chronic renal failure due to acquired cystic kidney disease. A 52-year-old male patient was examined for weight loss of 3 kg during over a period of 3 months. Abdominal computed tomography (CT) revealed a left adrenal mass (3.0 cm in size). Plasma adrenaline and noradrenaline were increased to 521 pg/ml and 1,341 pg/ml, respectively, and the metoclopramide provocative test was positive. Further, in the scintiscan using 123I-metaiodobenzylguanidine (MIBG), an accumulation of the radionuclide in the left adrenal tumor region was confirmed. The patient is currently under observation and conservative treatment due to the possible occurrence of arterial hypotension after resection of the tumor and to lesser possibility of the malignancy.

Subacute pulmonary hypertension due to pulmonary tumor microembolism as a clinical manifestation of occult gallbladder adenocarcinoma.

We report a 67-year-old man who developed pulmonary hypertension as an initial clinical manifestation of occult gallbladder adenocarcinoma. He had a 6-week history of persistent dry cough followed by progressive dyspnea on exertion. Physical examination and chest roentgenogram revealed signs of precapillary pulmonary hypertension. He died of shock 1 h after pulmonary angiography, which failed to show any intravascular filling defects. Autopsy disclosed a mucin-producing small adenocarcinoma (2 cm diameter) and a gallstone in the gallbladder with a few small metastases to peri-aortic, peri-bronchial and mediastinal lymph nodes. Macroscopically, there was no gross thrombotic pulmonary embolism or pulmonary metastases. However, microscopically, more than 60% of the small pulmonary arteries less than 1 mm in diameter were occluded with pulmonary tumor microemboli. This case emphasizes the need to include tumor pulmonary embolism in the differential diagnosis of pulmonary hypertension whether or not there is evidence of an underlying malignant tumor.

Pathogenesis of focal and random hepatocellular necrosis in endotoxemia: microscopic observation in vivo.

The present study was undertaken in rats to clarify the role of sinusoidal circulatory disturbances due to fibrin thrombi in the development of focal and random hepatocellular necrosis in endotoxemia. Sinusoidal circulation was examined microscopically in vivo in rats injected with endotoxin or heparin, or both. The sinusoids in places were occluded by adherent fibrin and neutrophils soon after endotoxin injection, and subsequently the sinusoidal blood flow stagnated, reversed, or detoured. Most of these sinusoidal circulatory disturbances recovered in a few hours. However, when the sinusoidal occlusion developed simultaneously in clusters of adjacent sinusoids, the sinusoidal circulatory disturbance persisted and induced ischemic foci and then hepatocellular coagulative necrosis. Pretreatment with heparin definitely prevented the adherence of fibrin and neutrophils to the sinusoidal walls, and focal hepatocellular necrosis did not appear. These results suggest that focal and random hepatocellular necrosis in endotoxemia is caused by circulatory disturbances due to fibrin thrombi in clusters of adjacent sinusoids.

Role of neutrophils and platelets in the pathogenesis of focal hepatocellular necrosis in endotoxaemia.

To clarify whether neutrophils and platelets are implicated in the pathogenesis of focal hepatocellular necrosis in endotoxaemia, we examined the relationship between the changes in neutrophils and platelets in peripheral blood and the degree of focal hepatocellular necrosis and serum transaminase activity in rats after endotoxin injection. The number of neutrophils in the peripheral blood decreased rapidly during the first hour after endotoxin injection and then increased. This initial decrease might be caused by the adhesion of neutrophils to pulmonary capillary walls, and the subsequent increase might be caused by granulocyte colony-stimulating factor mediated by endotoxin. However, there was no relationship between the degree of focal hepatocellular necrosis and the number of neutrophils sticking to the walls of hepatic sinusoids or the changes in the neutrophil count in the peripheral blood. The number of platelets in the peripheral blood decreased rapidly after endotoxin injection. There was a statistically significant relationship between the number of platelets in the peripheral blood and the level of serum transaminase activity: the fewer the platelets, the more severe was focal hepatocellular necrosis. The present study suggests that rapid and extensive consumption of platelets, rather than neutrophils sticking to the sinusoidal walls, is involved in the pathogenesis of focal hepatocellular necrosis in endotoxaemia.

Failure of protection against endotoxin hepatotoxicity by selenium.

The present study was undertaken in rats to test the ability of selenium to prevent endotoxin hepatotoxicity. There were no significant morphological changes in the liver and no abnormalities of liver function in rats given 0, 6.25 or 12.5 mumol of selenium. Endotoxin administration to these rats induced focal hepatocellular coagulative necrosis and increased serum transaminase activities. However, endotoxin hepatotoxicity and mortality of the rats given endotoxin after treatment with 6.25 or 12.5 mumol of selenium were not significantly lower than in those given endotoxin alone. These facts suggest that selenium does not prevent endotoxin hepatotoxicity.

Role of activated macrophages in augmentation of endotoxin hepatotoxicity.

In this study, to clarify the role of activated macrophages in the augmentation of endotoxin hepatoxicity, rats were pretreated with zymosan, an activator of macrophages, before the induction of endotoxin hepatotoxicity, and some were given pentoxifylline, an inhibitor of tumour necrosis factor production. The intravenous injection of zymosan induced many granulomas composed of macrophages in the lungs and the liver, while the intraperitoneal injection caused granulomas in the greater omentum. Endotoxin hepatotoxicity. as shown by focal and random hepatocellular coagulative necrosis and elevation of serum transaminase activities, was more intense in the rats pretreated with zymosan than in those which were not injected with zymosan. This augmented endotoxin hepatotoxicity was significantly inhibited by pentoxifylline treatment. These findings indicate that endotoxin hepatotoxicity may be augmented in the presence of activated macrophages which produce chemical mediators, particularly tumour necrosis factor.

Pathogenesis of centrilobular necrosis following congestion of the liver.

The exact pathogenesis of centrilobular necrosis following congestion of the liver is still unknown. We reviewed the clinical data related to systemic circulatory disturbance and histopathology of the liver and the gut in 320 autopsy subjects. Congestion of the liver alone was associated only with atrophy and loss of hepatocytes in centrilobular areas, but not with hepatocellular coagulative necrosis. In many patients with coagulative necrosis of centrilobular hepatocytes and congestion of the liver, fibrin thrombi and neutrophil infiltration in the sinusoids, which are the characteristic histopathological features of the liver in endotoxaemia, were found in and around the necrotic area. Congestion, erosion or haemorrhage of the intestinal mucosa, which may allow entrance of endotoxin into the liver through the portal vein, was seen in such patients. Prolonged hypotension or shock, which may lead to portal endotoxaemia, was present in half the patients with centrilobular necrosis and congestion of the liver. These results suggest that not only congestion of the liver but also portal endotoxaemia may be involved in the pathogenesis of centrilobular necrosis in patients with congestion of the liver.

Augmentation of endotoxin hepatotoxicity by zinc.

The present study was undertaken in rats to determine whether zinc protects against endotoxin hepatotoxicity and mortality. Treatment with zinc (50-200 mumol/kg body weight) alone or endotoxin (lipopolysaccharide B, Escherichia coli 026:B6, Difco, 2 mg/kg body weight) alone did not induce significant morphological changes in the liver parenchyma or any abnormalities in liver function tests. The mortality rate was 0%. In the rats pretreated with 100 mumol of zinc and then injected with endotoxin, the mortality rate, the incidence of focal hepatocellular coagulative necrosis and serum transaminase activity increased markedly. Eleven of the 12 rats pretreated with 200 mumol of zinc died within 4 h after endotoxin injection. In the rats pretreated with 50 mumol of zinc and then injected with endotoxin, there was no conspicuous change, in the mortality rate, liver function tests or morphology of the liver. These experimental data indicate that zinc increases the mortality rate in endotoxemic rats and augments biochemical and morphological evidence of endotoxin hepatotoxicity.

Hepatic failure after partial hepatectomy due to synergism between endotoxaemia and congestion of the liver.

To determine whether hepatic failure after partial hepatectomy is due to synergism between endotoxaemia and congestion of the liver, we examined endotoxin hepatotoxicity in partially hepatectomized rats with and without congestion of the liver. In partially hepatectomized rats without congestion of the liver, endotoxin administration induced slight elevation of the serum transaminase activity and mild or moderate hepatocellular necrosis in a few rats: these findings were not significantly different from those in sham operated rats treated with endotoxin. On the other hand, in partially hepatectomized rats with congestion of the liver, endotoxin administration induced marked elevation of serum transaminase activity and moderate or severe hepatocellular necrosis in almost all rats: these findings were significantly different from those in endotoxin-treated partially hepatectomized rats without congestion of the liver. These experimental data suggest that synergism between endotoxaemia and congestion of the liver may be a cause of hepatic failure after partial hepatectomy.

Influence of chronic alcohol consumption on the development of altered hepatocellular foci in rats.

The effect of chronic alcohol consumption on the development of altered hepatocellular foci was examined in 150 male Slc:Wistar rats fed an ethanol solution (0, 5 or 20%, w/v) ad libitum instead of drinking water. In the 120th week of the treatment period, the liver was examined histopathologically. There was no significant difference in the incidence, number and volume fractions of altered hepatocellular foci between the 0% and the 5% ethanol groups. In the 20% ethanol group, the incidence of altered hepatocellular foci was significantly higher than in the 0% ethanol group, and the number and the volume fraction of altered hepatocellular foci were significantly greater than in the 0% and the 5% ethanol groups. These results indicate that chronic consumption of a large amount of alcohol promotes the development of altered hepatocellular foci. However, there was no statistically significant difference in the incidence of benign liver cell tumours and hepatocellular carcinoma among the three groups.

A study of endotoxin-associated hepatotoxicity on proliferating hepatocytes.

It is thought that regeneration of the liver provides a state of preparedness for the Shwartzman reaction and contributes to the development of endotoxin-associated massive hepatic necrosis following partial hepatectomy. Therefore we examined endotoxin hepatotoxicity in rats with hepatic regeneration after 35% hepatectomy and in rats with liver cell proliferation induced by lead nitrate. Biochemical and histopathological studies showed no enhanced endotoxin hepatotoxicity in either partially hepatectomized rats or in rats with lead nitrate-induced liver cell proliferation. These results indicate that the development of endotoxin-associated hepatic damage after partial hepatectomy may not relate to regeneration and proliferation of the liver.

Mechanism of liver injury following ischemia.

To clarify whether ischemic liver injury is due to ischemia itself or reperfusion, histopathological and functional changes in the liver were examined before and after liver ischemia in rats with porto-systemic collateral channels. Effects of oxygen-derived free radical scavengers or an inhibitor of platelet aggregation on development of ischemic liver injury were also examined. Liver ischemia was produced by ligation of the portal vein and hepatic artery at liver hilum for 1 hr. The primary lesion of ischemic liver injury was cloudy swelling of liver cells in the periportal and midzonal regions; it developed during ischemia. The cloudy swelling of liver cells induced uneven distribution of sinusoidal blood flow after reperfusion, and consequently individual liver cell necrosis and focal hepatocellular necrosis in the midzonal regions developed later. Elevation of cytoplasmic enzyme activities in the serum after reperfusion was due to leakage across the damaged plasma membrane of liver cells. The treatment with superoxide dismutase, catalase, or heparin had not altered the liver injury that was attributed to ischemia, biochemically and histologically. These results suggest that ischemic liver injury is due to liver cell damage developed during ischemia, and that the ischemic liver injury is not alleviated or prevented by superoxide dismutase, catalase, or heparin.

Endotoxin hepatotoxicity augmented by ethanol.

To determine whether alcohol increases endotoxin hepatotoxicity, we administered ethanol (4.8 g/kg body wt in 4 ml of water) to rats through a gastric tube, then immediately injected endotoxin (2, 2.5, or 3 mg/kg body wt). In the rats pretreated with ethanol, the injection of 2 mg/kg body wt of endotoxin induced a slight rise of serum transaminase. However, when 2.5 mg/kg body wt of endotoxin was given, there were no significant histopathological or biochemical differences between the rats pretreated with ethanol and those pretreated with water. Moreover, there was no significant difference in mortality rates between the rats pretreated with ethanol and the controls when 3 mg/kg body wt (LD50) of endotoxin was injected. These results suggest that acute administration of alcohol enhances endotoxin hepatotoxicity when the dose of endotoxin is small, but that the effect of alcohol is masked when larger doses of endotoxin are given.

Serum antioxidant activity in uremic patients.

Serum antioxidant activity (AOA) was examined in 35 healthy subjects and 111 patients with chronic renal failure (CRF), consisting of 13 patients in the predialysis stage, 11 requiring the start of regular dialysis therapy (RDT) and 87 undergoing RDT. Serum AOA was determined by assaying serum activity to inhibit malondialdehyde (MDA) generation. AOA levels were significantly lower in CRF patients, and the lowest levels were noticed in patients with uremic symptoms requiring the start of RDT. These levels were restored to a subnormal level during RDT. Defective serum AOA appears to be an endogenous metabolic consequence in uremia. Sera with low AOA tended to show high MDA levels, indicating that patients with low serum AOA were susceptible to cellular injury by lipid peroxidation. It is proposed that defective serum AOA may contribute to a certain uremic toxicity through peroxidative cell damage.