Fatal fulminant hepatic failure associated with benzbromarone.
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Biomedical subjects
Publications and source records attributed to K Takase.
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Janus kinases (Jaks) play an important role in signal transduction via cytokine receptors. Tyk2 is a Janus kinase, and we developed tyk2-deficient mice to study the requirement for tyk2 in vivo. Tyk2-deficient mice show no overt developmental abnormalities; however, they display a lack of responsiveness to a small amount of IFNalpha, although a high concentration of IFNalpha can fully transduce its signal even in the absence of tyk2. Furthermore, IL-12-induced T cell function is defective in these mice. In contrast, these mice respond normally to IL-6 and IL-10, both of which activate tyk2 in vitro. These observations demonstrate that tyk2 plays only a restricted role in mediating IFNalpha-dependent signaling while being required in mediating IL-12-dependent biological responses.
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The anaesthetic and cardiopulmonary effects of combinations of medetomidine (Me), midazolam (Mi) and butorphanol (Bu) were evaluated in dogs. The characterization of anaesthetic effects was assessed using a scoring system. The combinations tested were 20 or 40 micrograms/kg Me and 0.5 mg/kg Mi (20Me-Mi or 40Me-Mi) followed by either an intravenous injection of physiological saline solution (PSS) or Bu (0.1 or 0.3 mg/kg). The mixture of Me and Mi was injected intramuscularly, followed 15 min later by an intravenous injection of Bu or PSS in all six groups. The combined Me-Mi induced deep sedation but not profound anaesthesia. The effect of the subsequent Bu administration was observed in the scores related to its analgesic effect. There were no significant differences between the two doses of Bu, following either 20Me-Mi or 40Me-Mi in the duration of anaesthesia, heart and respiratory rates, rectal temperature, and anaesthetic and analgesic scores except for palpebral reflex, and interdigital web clamping scores. Therefore, we concluded that the addition of 0.1 mg/kg Bu to Me-Mi elicits adequate anaesthesia with adequate analgesic effect, and side-effects such as bradycardia, hypertension, and slight respiratory acidosis in some dogs.
This study reports that postischemic apoptotic cell death of the hippocampal cornu ammonis (CA) 1 neurons is delayed in aged gerbils. Age-related changes in the process of CA1 neuronal death following transient ischemia was studied. Two groups of Mongolian gerbils were used in this study, which compared adult (4-month-old) and aged (24-month-old) animals by hematoxylin-eosin stain, in situ nick-end labeling (TUNEL method) and electron microscopy. In the process of neuronal death, neuronal loss of the aged group was histologically less severe than that of the adult group. TUNEL-positive cells were found on days 3-5 after ischemia in the adult group, while they were still found on day 7 in the aged group. The apoptotic process of the aged group was delayed compared to the adult group. Furthermore, lipofuscin was ultrastructurally observed inside the apoptotic body 5 days after ischemia in CA1 pyramidal neurons of the aged group. It is likely that colocalization of lysosomal enzyme cathepsin D with lipofuscin might be associated with the age-related alteration of lysosomal system in the neurons. Altogether these data suggest that age-related lysosomal changes might affect the apoptotic cascade process in postischemic CA1 neurons.
Survivin is a recently described inhibitor of apoptosis. Because suppression of apoptosis is important for carcinogenesis and tumor growth, we investigated the expression and function of survivin in human hepatocellular carcinomas (HCCs). We have shown that 4 HCC cell lines and 7 out of 8 human HCC tissues expressed survivin messenger RNA (mRNA), whereas expression of survivin mRNA was not detected in normal liver and nontumor areas of these tissues using the reverse transcription polymerase chain reaction. Survivin was detected primarily in the nucleus by immunofluorescence staining of HCC cells. In addition, 14 of 20 (70%) HCC tissues showed positive nuclear staining for survivin, whereas nontumor tissues showed little detectable staining by immunohistochemistry. Survivin expression strongly correlated with the proliferation index but not significantly with the apoptosis index in HCC tissues. Therefore, we performed cell cycle analysis after survivin transfection and showed that overexpression of survivin resulted in a decrease in the G(0)/G(1) phase and an increase in the S phase in all 4 HCC cell lines. Furthermore, we have found that survivin interacted with cyclin-dependent kinase 4 (Cdk4) and overexpression of survivin released p21(WAF1/Cip1) (p21) from Cdk4. From these results, we conclude that survivin promotes cell proliferation by interacting with Cdk4 and releasing p21 from Cdk4. This may play an important role in carcinogenesis and progression of human HCCs.
TNF-related apoptosis-inducing ligand (TRAIL) selectively induces apoptosis in various transformed cell lines but not in almost-normal tissues. It is regulated by 2 death receptors, TRAIL receptor 1 (TRAIL-R1) and TRAIL-R2, and 2 decoy receptors, TRAIL-R3 and TRAIL-R4. We investigated the expression of TRAIL-R- and TRAIL-induced apoptosis in human hepatocellular carcinomas (HCCs). TRAIL-R1, -R2, and -R4 were expressed in 6 HCC cell lines examined, but TRAIL-R3 was expressed in only 2 of the 6 cell lines. In addition, immunohistochemical results revealed a high and prevalent expression of TRAIL-R1 and -R2 in human HCC tissues. Despite the expression of TRAIL-R1 and -R2, all 6 HCC cell lines showed resistance to TRAIL-induced apoptosis with no relation to nuclear factor kappa B (NF-kappaB) levels induced by TRAIL. TRAIL-induced death signal was inhibited with both decreased caspase-8 and caspase-3 activity. However, TRAIL induced significant apoptosis in the presence of a subtoxic level of actinomycin D, indicating that the TRAIL-induced apoptotic pathway is in place in these cell lines. In addition, we found that treatment with conventional chemotherapeutic agents, doxorubicin and camptothecin, dramatically augmented TRAIL-induced cytotoxicity in most of the HCC cell lines. Actinomycin D and camptothecin almost completely suppressed NF-kappaB induction by TRAIL, whereas doxorubicin had little effect. These results indicate that TRAIL, in combination with chemotherapeutic agents, may have therapeutic potential in the treatment of human HCC.
Laparoscopic findings in a 32-year-old woman presenting with Alagille syndrome are reported. The liver surface showed a segmental whitish discoloration on the surface of both lobes with a transverse sulcus which was not stained enough after an intravenous injection of indocyanine green (ICG). These findings suggested an acquired bile duct injury in addition to a congenital anomaly of the bile duct in this patient.
BACKGROUND: The mechanism of acute pancreatitis-induced hepatocellular injury is unclear. We have observed hepatocyte apoptosis in rat acute necrotizing pancreatitis. These studies were designed to determine the mediator(s) responsible for hepatocyte apoptosis and to clarify the significance of macrophages as its source. METHODS: A rat sodium deoxycholate-induced pancreatitis model was used. Immunohistochemical studies for apoptosis-inducing mediators on hepatocytes were examined in the liver and on the peritoneal macrophages. The levels of transforming growth factor-beta1 (TGF-beta1) were also evaluated quantitatively with an enzyme-linked immunosorbent assay. Induction of apoptosis on the hepatocytes was evaluated by in situ nick-end labeling and tissue DNA fragmentation enzyme-linked immunosorbent assay. Finally, the effects of TGF-beta1 neutralization and macrophage depletion were examined. RESULTS: In the liver and the peritoneal macrophages, strong expression of TGF-beta1 was detected early in the course of pancreatitis. In sodium deoxycholate-induced pancreatitis, the levels of TGF-beta1 were also elevated in the plasma (9.2 +/- 0.8 ng/mL), in the pancreatitis-associated ascitic fluid (11.5 +/- 0.6 ng/mL), and in the liver homogenate (2.8 +/- 0.3 ng/g of liver tissue). Moreover, the amount of fragmented DNA of the liver with pancreatitis was 290% +/- 20% of that with a sham operation and serum alanine aminotransferase levels elevated to 248.2 +/- 67.0 IU/L. TGF-beta1 neutralization partly blocked the positive labeling on the nuclei of the hepatocytes, the elevation of the amounts of fragmented DNA (205% +/- 10% of sham operation), and the serum alanine aminotransferase level (144.2 +/- 14.9 IU/L). On the other hand, the macrophage depletion caused a marked decrease in the TGF-beta1 protein level in the plasma (4.8 +/- 1.2 ng/mL) or in the pancreatitis-associated ascitic fluid (8.0 +/- 1.0 ng/mL). Moreover, the macrophage depletion completely inhibited the elevation of the TGF-beta1 protein level in the liver homogenate (1.5 +/- 0.4 ng/g of liver tissue), and thereafter decreased the amounts of the positive labeling on the nuclei of the hepatocytes and decreased the amount of fragmented DNA (120% +/- 18% of sham operation) and the serum alanine aminotransferase elevation (119.2 +/- 24.2 IU/L). CONCLUSIONS: In a model of sodium deoxycholate-induced pancreatitis, macrophages are responsible for pancreatitis-induced hepatocellular injury by means of apoptosis, and macrophage-derived TGF-beta1 is one of the major factors inducing the hepatocyte apoptosis.
BACKGROUND: Apoptosis of hepatocytes has been reported to be involved in liver failure complicated with systemic manifestations such as endotoxemia. We hypothesized that hepatocyte apoptosis occurs in severe acute pancreatitis. METHODS: Induction of apoptosis was evaluated in the liver from rats with necrotizing pancreatitis. Apoptosis-inducing activity of the pancreatitis-associated ascitic fluid on hepatocytes was evaluated in vivo by intraperitoneal injection of the ascitic fluid and in vitro using rat primary hepatocyte culture. RESULTS: Apoptosis was detected in hepatocytes in the rats both with severe acute pancreatitis and with the intraperitoneal injection of the ascitic fluid by in situ nick-end labeling and DNA fragmentation. Apoptotic change and hepatic injury were ameliorated by administration of an interleukin-1 beta-converting enzyme inhibitor. The ascitic fluid exhibited cytocidal activity in rat primary hepatocyte culture via apoptosis, which was confirmed by DNA fragmentation, by cell cycle analysis, and by nuclear fragmentation. The neutralizing antibody for transforming growth factor-beta 1 partially blocked the apoptosis induction but the antibody to tumor necrosis factor-alpha had no effect. CONCLUSIONS: Apoptotic cell death occurs in hepatocytes in severe acute pancreatitis partially via transforming growth factor-beta 1 in the pancreatitis-associated ascitic fluid.
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PURPOSE: To investigate the influence of [methyl-3H]thymidine ([3H]Tdr) incorporated into human haemopoietic cell lines. MATERIALS AND METHODS: HL-60, Molt-4, Jurkat, Raji and SKW6-CL4 cells were incubated in the presence of [3H]Tdr. Cell proliferation, cell viability, DNA fragmentation and expression of caspase-3 and Bcl-2 families were examined. The cell-cycle of HL-60 was analysed using flow cytometry. RESULTS: In HL-60, Molt-4 and Jurkat, cell death was accompanied by DNA nucleosomal fragmentation and activation of caspase-3. In Raji and SKW6-CL4, it was accompanied by neither. Protein levels of Bcl-2 and Bad in HL-60 and Molt-4 did not significantly change, and that of Bax was decreased after a 3-day incubation. HL-60 incubated in the presence of 74 or 185 kBq/ml [3H]Tdr arrested at G2/M phase, and then underwent apoptosis. In 7.4 kBq/ml, the cell-cycle progressed after the delay in S-phase. CONCLUSIONS: Two different modes of cell death were observed when [3H]Tdr was incorporated into the human haemopoietic cell lines. Incorporation into HL-60 cells resulted in delay of S-phase progression, arrest at G2/M and apoptosis.
A domain-exchanged chimeric alpha-lactalbumin (alpha-LA), which consisted of the alpha-domain of human alpha-LA and the beta-domain of bovine alpha-LA, was constructed. Like native alpha-LA, the chimeric protein was in a molten globule state in the absence of Ca(2+) at neutral pH and low salt concentration. The stability of the molten globule state of the constructed chimeric protein was identical to that of the recombinant human protein and was higher than that of the recombinant bovine protein. The stability of the molten globule state of alpha-LA is defined by the stability of the alpha-domain.
We previously reported that serum hepatocyte growth factor (HGF) levels are elevated in patients with acute pancreatitis and that pancreatitis-associated ascitic fluid (PAAF) contains cytotoxic factor(s) inducing apoptosis on Madin-Darby canine kidney (MDCK) cells. In this study, plasma HGF levels and HGF tissue distribution were investigated in rats with experimental acute pancreatitis, and the effects of HGF on the cytotoxic activity and apoptosis-inducing activity of PAAF also were examined. Plasma HGF levels were elevated in rats with two experimental pancreatitis models of different grades of severity. The degree of its elevation was correlated with the severity and the organ dysfunctions. In rats with severe pancreatitis, HGF protein and messenger RNA (mRNA) levels significantly increased in liver, kidney, and lung, which were injured organs. When anti-HGF neutralizing antibody was administered in severe pancreatitis, liver dysfunction worsened, and apoptotic cells increased in kidney. Recombinant HGF inhibited the cytocidal activity of PAAF on MDCK cells in a dose-dependent manner. Moreover, recombinant HGF prevented the apoptotic cell death (DNA fragmentation, nuclear fragmentation, and caspase-3 activation) induced by PAAF. These results suggest that HGF is produced in injured organs and may function as an organotrophic and antiapoptotic factor against the organ injuries in acute pancreatitis.
A recombinant alpha-amylase from Bacillus stearothermophilus was found to be produced as several isoforms arising from different N--terminal processing. Some of those isoforms were purified to homogeneity and crystallized at 293 K using the hanging-drop vapour-diffusion method under the following conditions: 35 mM sodium acetate (pH 4.6), 6.25%(v/v) 2-propanol, in the presence of 1.23%(w/v) acarbose (a pseudo-oligosaccharide inhibitor) in the drop. The crystals diffracted beyond 2.0 A resolution using synchrotron radiation at the Photon Factory, Tsukuba. They belong to the monoclinic space group P2(1), with unit-cell parameters a = 53.7 (2), b = 92.9 (4), c = 53.2 (2) A, beta = 109.4 (1) degrees.
We have cloned and sequenced an Aspergillus oryzae genomic DNA fragment that encodes a fructose-1,6-bisphosphatase gene (fbpA) with the aim of studying transcriptional regulation mechanisms involved in basic metabolism. Expression of fbpA was repressed in the presence of glucose, but not in the presence of pyruvate or sodium acetate in the medium. The CreA and FacB element found in the fbpA 5'-flanking region may be important in fbpA regulation.
A seven-month-old, male Shih Tzu dog weighing 3.7 kg had an immature cataract in its left eye. A biomicroscopic examination revealed numerous vacuolations in the posterior cortices with nucleus cataracts, covered by an intact anterior lens capsule. The changes observed by ocular sonographic examination (OSG) of the left eye were hyperechoic, and a funnel-cone shape was observed posteriorly with cortex hyperechogenicity in the lens. The left eye was diagnosed as having a posterior lenticonus with congenital cataract. Phacoemulsification was performed on the left eye as diagnostic treatment of the posterior lenticonus and cataract. Postoperative OSG on the left eye revealed a V-shaped linear echo that was indicative of a posterior capsule of the lens. Moreover, it was confirmed that hyperechoic cataract material inside the lens had disappeared.
The MET95 strain of a lentogenic Newcastle disease virus (NDV) isolated from a broiler in Japan, showed unique hemagglutination (HA) activity. The MET95 strain failed to show HA when examined by rapid glass plate method although they showed HA titer of 1:1,024 by micro-plate method. This unique HA was also observed after the MET95 strain was passaged ten times in chickens. The failure of HA by rapid glass plate method was not shown in any other NDVs examined.