Factors affecting postoperative prognosis in the solitary-nodule type of hepatocellular carcinoma: experience of 132 cases in our institute

A retrospective analysis of clinical and pathological factors was performed on 132 surgical cases with solitary-nodule type HCC in our hospital. The overall cancer-free survival rates after 1, 3 and 5 years were 82.2%, 42.3% and 26.5%, respectively. With univariate analysis, the significant prognostic factors for survival were tumor size, cancer cell infiltration of the fibrous capsule of the tumor (fc-inf), invasion into portal vein (vp), and intrahepatic metastasis (im), while significant prognostic factors for non-recurrence were tumor size, fc-inf, vp, im, Edmondson-Steiner's classification and perioperative blood transfusion. With multivariate analysis for recurrence, significant factors were vp, clinical stage (CS), and perioperative blood transfusion. Therefore, prognostic factors for long-term survival in surgical cases of HCC are thought to be good hepatic function, absence of portal invasion, and avoidance of perioperative blood transfusion if possible.

Thoracoscopic microwave coagulation therapy for hepatocellular carcinoma

Thoracoscopic microwave coagulation therapy (MCT) is a new therapeutic approach for hepatocellular carcinoma (HCC) in segments VII and VIII, which allows minimal access to the tumor and complete tumor ablation. In this study, four patients with HCC in segments VII and VIII underwent thoracoscopic MCT as a less invasive therapeutic option due to advanced liver cirrhosis and/or severe complications. Tumor sizes ranged from 15 to 30 mm in diameter and the tumors were well differentiated in 2 patients, moderately in one and poorly in one patient. Microwave irradiation was performed at an 80 W output with a 60-sec duration via a thoracoscopic route and the total duration ranged from 4 to 24 min (mean: 17 min). Patients recovered rapidly to preoperative conditions and no mortality was occurred. Complications were observed in one patient, including pleural effusion and fever elevation, but were cured conservatively. Postoperative computed tomography (CT) showed complete tumor ablation with a cancer-free margin, which is thought to be equivalent to a limited hepatic resection. This preliminary study suggests that thoracoscopic MCT might be a new, less invasive option providing a cure for HCC in segments VII and VIII in patients with advanced liver cirrhosis and severe complications.

Indications for palliative reduction surgery for hepatocellular carcinoma with multiple intrahepatic metastases

We evaluated the efficacy of and the indications for palliative reduction surgery as a procedure to improve the prognosis of hepatocellular carcinoma (HCC) patients with multiple intrahepatic metastases. From January 1986 to October 1997, 25 HCC patients with multiple intrahepatic metastases who underwent necessary palliative reduction surgery due to advanced disease, were participated in the study. The 1-, 3-, 5-year survival rates of 25 patients with reduction surgery were 54.7%, 29.9%, 22.4%, respectively. Moreover, the 1-, 3-, 5-year survival rates of patients with some postoperative supplemental treatment were 68.8%, 41.2% and 30.9%, respectively. All 6 patients who had been alive for more than 3 years had had primary tumors with diametric sizes of approximately 5 cm and had undergone, at most, one segmentectomy. These patients received postoperative supplemental treatments. The indication for palliative reduction surgery for HCC patients with multiple intrahepatic metastases was patients with a relatively small primary tumor (around 5 cm) which could be removed by one segmentectomy or less.

Full-length GBV-C/HGV genomes from nine Japanese isolates: characterization by comparative analyses

The genomes of nine GBV-C/HGV isolates from Japanese chronic hepatitis patients were fully sequenced and characterized. They shared 85% nucleotide sequence homology with previously characterized isolates from the US and West Africa. Homology studies and phylogenetic analyses showed that the Japanese isolates formed a third group distinct from the established groups 1 and 2. The genetic distances between the three groups of GBV-C/HGV were very similar to the distances between the two classical swine fever virus (CSFV) serotypes, which suggested that they might belong to a separate GBV-C/HGV serotype. Plot similarity analysis comparing the three groups exposed relatively conserved terminal non-coding regions. Hairpin structures predicted in the Japanese isolates are probably involved in viral replication. The region coding E1-E2-NS-2 showed the least similarity (80%); in HCV the similarity here is only 50% due to its hypervariability. NS-3 and NS-5b that respectively encode the helicase/protease and RNA-dependent RNA polymerase, had a high degree of amino acid homology, suggesting a high degree of functional constraint in this region. The NS-5b nucleotide sequence was highly conserved perhaps because of constraints from RNA secondary structure and/or an open reading frame in the negative strand.

The effects of intermittent exposure to hypoxia during endurance exercise training on the ventilatory responses to hypoxia and hypercapnia in humans

The present study was performed to investigate the effects of a combination of intermittent exposure to hypoxia during exercise training for short periods on ventilatory responses to hypoxia and hypercapnia (HVR and HCVR respectively) in humans. In a hypobaric chamber at a simulated altitude of 4,500 m (barometric pressure 432 mmHg), seven subjects (training group) performed exercise training for 6 consecutive days (30 min x day(-1)), while six subjects (control group) were inactive during the same period. The HVR, HCVR and maximal oxygen uptake (VO2max) for each subject were measured at sea level before (pre) and after exposure to intermittent hypoxia. The post exposure test was carried out twice, i.e. on the 1st day and 1 week post exposure. It was found that HVR, as an index of peripheral chemosensitivity to hypoxia, was increased significantly (P < 0.05) in the control group after intermittent exposure to hypoxia. In contrast, there was no significant increase in HVR in the training group after exposure. The HCVR in both groups was not changed by intermittent exposure to hypoxia, while VO2max increased significantly in the training group. These results would suggest that endurance training during intermittent exposure to hypoxia depresses the increment of chemosensitivity to hypoxia, and that intermittent exposure to hypoxia in the presence or absence of exercise training does not induce an increase in the chemosensitivity to hypercapnia in humans.

A hydrolase enzyme inactivating endogenous ligands for cannabinoid receptors

Cannabinoids are psychoactive components of marijuana, and bind to specific G protein-coupled receptors in the brain and other mammalian tissues. Anandamide (arachidonoylethanolamide) was discovered as an endogenous agonist for the cannabinoid receptors. Hydrolysis of anandamide to arachidonic acid and ethanolamine results in the loss of its biological activities. The enzyme responsible for this hydrolysis was solubilized, partially purified from the microsomes of porcine brain, and referred to as anandamide amidohydrolase. In addition to the anandamide hydrolysis, the enzyme preparation catalyzed anandamide synthesis by the condensation of arachidonic acid with ethanolamine. Several lines of enzymological evidence suggested that a single enzyme catalyzes both the hydrolysis and synthesis of anandamide. This reversibility was confirmed by the use of a recombinant enzyme of rat liver overexpressed in COS-7 cells. However, in consideration of the high Km value for ethanolamine as a substrate for the anandamide synthesis, the enzyme was presumed to act as a hydrolase rather than a synthase under physiological conditions. The recombinant enzyme acted not only as an amidase hydrolyzing anandamide and other fatty acid amides but also as an esterase hydrolyzing methyl ester of arachidonic acid. 2-Arachidonoylglycerol, which was found recently to be another endogenous ligand, was also efficiently hydrolyzed by the esterase activity of the same enzyme. The anandamide hydrolase and synthase activities were detected in a variety of rat organs, and liver showed by far the highest activities. A high anandamide hydrolase activity was also detected in small intestine but only after the homogenate was precipitated with acetone to remove endogenous lipids inhibiting the enzyme activity. The distribution of mRNA of the enzyme was in agreement with that of the enzyme activity.

Dumb-bell shaped tuberculous abscess across the greater sciatic notch compressing both sciatic nerves

We report an instructive case of a 65-year-old man who presented with a dumb-bell shaped tuberculous abscess across the greater sciatic notch bilaterally compressing both sciatic nerves. Clinical symptoms progressed slowly and mimicked lumbar radiculopathy, thus delaying an accurate diagnosis. Anterolateral retroperitoneal and posterolateral gluteal approaches of the greater sciatic notch as well as the acetabulum on both sides were followed in order to provide safe viewing and resection of the abscess. The abscess wall was adherent to the sciatic nerve and surrounding blood vessels. The symptoms completely disappeared after resection of the abscess.

Cross-linking of Fc(gamma)-receptor on monocytes inhibits hepatitis C virus-specific cytotoxic T-lymphocyte induction in vitro

In hepatitis C virus (HCV) infection, immune complex (IC)-type virus particles are frequently observed in circulation. The IC leads to cross-linking of Fcgamma receptors (FcgammaR) on monocytes and exerts immunoinhibitory function. To test the roles of IC in HCV-specific cytotoxic T lymphocyte (CTL) induction, we generated HCV CTL from peripheral blood mononuclear cells of chronic hepatitis C patients with or without HCV-IC- or immunoglobulin G (IgG)-coated culture plates and compared their lytic activities. HCV-IC or adherent IgG, which induces FcgammaR cross-linking, significantly reduced CTL activity. Expression of B7-1 on monocytes decreased on adherent IgG. In addition, tumour necrosis factor-alpha (TNF-alpha) and transforming growth factor-beta1 (TGF-beta1) production increased from cells on adherent IgG and their mRNA expression in monocytes was enhanced. Anti-TNF-alpha antibody during induction on adherent IgG inhibited lysis; however, anti-TGF-beta completely reversed its inhibitory effect. These results demonstrated that HCV-IC or adherent IgG impaired HCV-CTL induction in vitro. The FcgammaR-mediated CTL suppression occurred via decreased expression of monocyte B7-1 and/or enhanced production of TGF-beta1.

Prognostic value of DNA ploidy and proliferating cell nuclear antigen in gastric cancer

DNA ploidy and the labeling index (LI) of proliferating cell nuclear antigen (PCNA) in gastric cancers were determined using cytofluorometry and immunohistochemistry, respectively, and the prognostic value of these two parameters was evaluated. Of 66 patients with advanced gastric cancers treated with radical resection, 27 with aneuploidy and a high PCNA-LI (> or = 40) showed the lowest 5-year survival rate (38%). Twenty patients with diploid cancers and a high LI showed a lower 5-year survival rate (59%) than the 15 patients with diploid cancers and a low LI (<40), who had the highest 5-year survival rate (86%). A multivariate analysis showed that the grouping based on the ploidy and the LI was an independent prognostic factor. Thus, the combination of DNA ploidy and PCNA-LI may be a useful prognostic indicator for advanced gastric cancers.

Biosynthesis and degradation of bioactive fatty acid amides in human breast cancer and rat pheochromocytoma cells--implications for cell proliferation and differentiation

The endogenous cannabinoid, anandamide (arachidonoylethanolamide), and the sleep-inducing factor, oleamide (cis-9-octadecenoamide), represent two classes of long-chain fatty acid amides with several neuronal actions and metabolic pathways in common. Here we report that these two compounds are present in human breast carcinoma EFM-19 cells and rat adrenal pheochromocytoma PC-12 cells, together with the enzyme responsible for their degradation, fatty acid amide hydrolase, and the proposed biosynthetic precursors for arachidonoylethanolamide and related acylethanolamides, the N-acyl-phosphatidylethanolamines. Lipids extracted from cells labelled with [14C]ethanolamine contained radioactive compounds with the same chromatographic behaviour as arachidonoylethanolamide and acyl-PtdEtns. The levels of these compounds were not influenced by either stimulation with ionomycin in EFM-19 cells or two-week treatment with the nerve growth factor in PC-12 cells. The chemical nature of arachidonoylethanolamide, related acylethanolamides and the corresponding acyl-PtdEtns was confirmed by gas chromatographic/mass spectrometric analyses of the purified compounds, which also showed the presence of higher levels of oleamide. The latter compound, which does not activate the central CB1 cannabinoid receptor, exhibited an anti-proliferative action on EFM-19 cells at higher concentrations than arachidonoylethanolamide (IC50 = 11.3 microM for oleamide and 2.1 microM for arachidonoylethanolamide), while at a low, inactive dose it potentiated an arachidonoylethanolamide cytostatic effect. The CB1 receptor selective antagonist SR 141716A (0.5 microM) reversed the effect of both arachidonoylethanolamide and oleamide. EFM-19 cells and PC-12 cells were found to contain a membrane-bound [14C]arachidonoylethanolamide-hydrolysing activity with pH dependency and sensitivity to inhibitors similar to those previously reported for fatty acid amide hydrolase. This enzyme was inhibited by oleamide in both intact cells and cell-free preparations. The presence of transcripts of fatty acid amide hydrolase in these cells was shown by northern blot analyses of their total RNA. The rate of [14C]arachidonoylethanolamide hydrolysis by intact cells, the kinetic parameters of arachidonoylethanolamide enzymatic hydrolysis and the amounts of the fatty acid amide hydrolase transcript, were not significantly influenced by a two-week treatment with nerve growth factor and subsequent transformation of PC-12 cells into neuron-like cells. These data show for the first time that: (a) induction by nerve growth factor of a sympathetic neuronal phenotype in PC-12 cells has no effect on arachidonoylethanolamide/oleamide metabolism, (b) arachidonoylethanolamide and oleamide are autacoid suppressors of human breast cancer cell proliferation. Moreover these data lend conclusive support to the previous hypothesis that oleamide may act as an enhancer of arachidonoylethanolamide actions through competitive inhibition of its degradation.

Basic studies on N''-ursodeoxycholyldiethylenetriamine-N,N,N'-triacetic acid for the dissolution of calcified gallstones

A novel calcium-chelating agent, N"-ursodeoxycholyldiethylenetriamine-N,N,N'-triacetic acid (UDCA-DTTA), was synthesized to study its ability to dissolve calcified gallstones. The chelating activity of the compound was demonstrated by dissolving calcium carbonate in vitro at a high dissolution rate. In the presence of the agent, sliced human gallstone with a composition of more than 50% calcium bilirubinate was thoroughly dissolved, indicating that calcium bilirubinate was dissolved from the gallstone. The ability to dissolve calcium was comparable to that of EDTA. However, the laminar structure of the sliced gallstone did not disappear in the presence of EDTA, whereas the structure disappeared in the presence of UDCA-DTTA. All these results indicate that UDCA-DTTA is an interesting compound as a parent substance for developing a prodrug for an oral or intravenous agent to dissolve calcium-containing gallstones.

[Bacteriological and virological studies on the cause of sporadic acute gastroenteritis in Tama, Tokyo (1991-1996)]

Between May 1991 and December 1996, bacteriological and virological investigations on the fecal samples from patient of infantile diarrhea (155 cases), or infectious gastroenteritis (1,409 cases) diagnosed with 9 medical institutions in Tama of Tokyo were carried out. Of 1,564 samples, 722 (46.2%) were enteropathogen positive cases, and mixed infection was also observed in about 15% of the positive cases. Among 13 different kinds of enteropathogens identified, the most prevalent one was pathogenic E. coli (20.7%), followed by Campylobacter spp. (10.0%), Rotavirus (8.8%), Salmonella spp. (3.9%), Adenovirus (1.9%), ECHO virus (0.9%), Vibrio parahaemolyticus (0.8%), Poliovirus (0.7%), Aeromonas spp. and Coxsackie B virus (both 0.6%). Furthermore, SRSV was confirmed in 82 out of 619 patients (13.2%) for 2 years (1995 and 1996). In addition, Shigella sonnei (3 cases), S. Paratyphi-A (1 case) and enterohemorrhagic E. coli O157: H7 (2 cases) were also detected. A higher detection ratio was recorded in February, August and November, reflecting respectively by month a highly frequency of Rotavirus, enteric bacteria causing food poisoning and SRSV. With reference to the isolates, the most of pathogenic E. coli belonged to enteropathogenic serotype E. coli (EPEC), and S. Enteritidis was most prevalent serotype.

Pharmacokinetic and pharmacodynamic evaluation for tissue-selective inhibition of cholesterol synthesis by pravastatin

The tissue-selective inhibition of cholesterol synthesis by pravastatin was evaluated pharmacokinetically and pharmacodynamically. Plasma, tissue, urine, and bile concentrations were measured after i.v. bolus injection of pravastatin to rats at various doses. The total body clearance and steady state volume of distribution decreased with increasing dose. A saturable biliary excretion was also observed. The time course of plasma and liver concentrations was described by a three-compartment model, consisting of a central compartment, a deep compartment with an nonsaturable uptake process, and a shallow compartment with saturable uptake and nonsaturable elimination processes. It suggests that a mechanism for the decrease in the total body clearance and distribution volume might be explained by a saturation of pravastatin uptake into the liver. Plasma concentration data after oral administration was also fitted to the same model by connecting an absorption compartment to the shallow compartment. The inhibitory activity of pravastatin against cholesterol synthesis in liver could be related to the concentration in the shallow compartment via a sigmoidal Emax model and the obtained pharmacodynamic parameters were comparable to those in vitro. Results suggest that the carrier-mediated hepatic uptake of pravastatin is actually responsible for the hepatoselective inhibition of cholesterol synthesis under physiological conditions.

Enzymatic activity and partial purification of solanapyrone synthase: first enzyme catalyzing Diels-Alder reaction

In cell-free extracts of Alternaria solani, an enzymatic activity converting prosolanapyrone II to solanapyrones A and D via oxidation and subsequent Diels-Alder reaction has been found. Chromatography with DEAE-Sepharose provided two active fractions, pools 1 and 2. The former fraction converted prosolanapyrone II to solanapyrones A and D in a ratio of 2.2:1 with optical purities of 99% and 45% ee, respectively. The latter fraction did so in a ratio of 7.6:1 with 99% and nearly 0% ee, respectively. The enzyme partially purified from pool 2 native molecular weight of 40-62 kD and a pl of 4.25. The high reactivity of prosolanapyrone III in aqueous solution and the chromatographic behavior of the enzyme in pool 2 suggest that a single enzyme catalyzes both the oxidation and Diels-Alder reaction.

Identification of lipid inhibitor of mammalian phospholipase D

Phospholipase D (PLD) is implicated in important cellular processes, such as hormone action, inflammation, secretion, mitogenesis, and neural activity. Recent studies using cell-free systems have shown that the enzyme activity is modulated by both positive and negative regulators. During an attempt to purify PLD from pig colon mucosa, we noted the presence of a PLD inhibitor in the tissue extract. The inhibitor was purified and identified as comprising lysophosphatidylserine, phosphatidylinositol, and lysophosphatidylinositol, of which lysophosphatidylserine was the most potent. These lipids affected all of the PLD isoforms examined, oleate-dependent PLD, ARF-dependent PLD (PLD1a, PLD1b), and phosphatidylinositol 4,5-bisphosphate-dependent PLD (PLD2), in the concentration range of the 1 or 10 microM order. In contrast to lysophosphatidylserine, the diacyl counterpart phosphatidylserine was without effect in the same concentration range. PLD inhibition by lysophosphatidylserine could not be reversed by an increase in the concentration of the substrate phosphatidylcholine or activator phosphatidylinositol 4,5-bisphosphate.

Studies of postoperative transarterial infusion chemotherapy for liver metastasis of colorectal carcinoma after hepatectomy

BACKGROUND/AIMS

The aim of this study was to evaluate the efficacy of postoperative transarterial infusion chemotherapy (PTIC) for the prevention of metastatic liver cancer recurrence after hepatectomy following curative surgery for colorectal carcinoma.

METHODOLOGY

Thirty-eight patients who underwent curative hepatectomy for metastatic liver cancer from colorectal carcinoma were studied. Ten out of the 38 patients received PTIC (experimental group) and 28 patients did not receive chemotherapy (control group). PTIC was performed with an intrahepatic indwelling catheter, which was set-up for 3 weeks and repeated 3 times in two monthly intervals.

RESULTS

In the control group, no significant differences were observed in the survival between patients with a single hepatic nodule and those with multiple hepatic nodules. Between patients with hepatic tumors of more than 3 cm in diameter and those with tumors less than 3 cm, and between patients with tumors located at H1 and H2, no significant differences were seen, either. However, the 5-year survival rate of the patients with metachronous liver metastases was 90% which was significantly better than for those patients with synchronous liver tumors (p < 0.05). The 100% of 3- and 100% of 4-year survival rates of the experimental group were significantly better than the 60% and 47% respectively of the control group (p < 0.05). The non-recurrence rate in the remnant liver was also significantly better in the experimental group than that in the control group (p < 0.01). The adverse effect of this protocol was negligible.

CONCLUSION

We conclude that PTIC improved the survival and non-recurrence rate in the remnant liver of the patients with liver metastases from colorectal cancer after hepatectomy, and was considered to be safe and an important protective factor for the prevention of recurrence of liver metastases after hepatectomy.

Role of glutamate receptors and voltage-dependent calcium and sodium channels in the extracellular glutamate/aspartate accumulation and subsequent neuronal injury induced by oxygen/glucose deprivation in cultured hippocampal neurons

Ischemia is believed to induce neuronal damage by causing a sustained increase in the level of extracellular excitatory amino acids. In our study, we have examined the relationship between oxygen/glucose deprivation-induced changes in extracellular glutamate/aspartate level and subsequent neuronal injury by pharmacological manipulation of glutamate receptors and calcium and sodium channels. Cultured hippocampal neurons were exposed to combined deprivation of oxygen/glucose for 40 to 50 min. These cultures developed acute neuronal swelling and widespread neuronal degeneration over the next 20 hr. The extracellular levels of glutamate and aspartate at the end of the oxygen/glucose deprivation period were measured by high-performance liquid chromatography, and neuronal injury was assessed by lactate dehydrogenase efflux assay after subsequent aerobic incubation of the cells in normal medium for 20 hr. Both N-methyl-D-aspartate and non- N-methyl-D-aspartate receptor antagonists attenuated the extracellular level of glutamate/aspartate and the neuronal injury. L-type, N-type and P-type calcium channel blockers each significantly attenuated the neuronal injury, although the increase in the extracellular glutamate/aspartate was not significantly inhibited by any subtype-specific calcium channel blocker alone. A combination of calcium channel blockers of the three subtypes showed the most prominent neuroprotective effect and inhibited glutamate release. The sodium channel blocker tetrodotoxin also attenuated both glutamate efflux and neuronal injury. These observations suggest that the overactivation of glutamate receptors, calcium channels and sodium channels leads to excitotoxic neuronal injury through enhancing glutamate efflux into the extracellular space under the condition of oxygen/glucose deprivation.

Fracture of the hamate hook presenting as median nerve palsy

We report a case of fracture of the hamate hook presenting as median nerve palsy and discuss the etiology of this rarely seen complication. We consider that the median nerve palsy in this case was due to direct nerve compression within the carpal tunnel caused by a displaced fractured hook fragment.

Mother-to-infant transmission occurs more frequently with GB virus C than hepatitis C virus

A total of 107 hepatitis C virus (HCV)-infected pregnant women were screened for GB virus C (GBV-C) RNA in their sera, and 11 (10.3%) were positive. Among 11 infants born to these HCV/GBV-C co-infected mothers, GBV-C RNA was detected in 7 (63.6%) while HCV RNA was found in 1 (9.1%) within 1 year after birth: this difference was statistically significant (p = 0.023). The mothers of infected infants had significantly higher serum titers of GBV-C RNA than those of uninfected infants: 10(6.7 +/- 0.5) vs 10(4.0 +/- 1.0) copies/ml in average (p = 0.001). The baby in whom HCV RNA was found was also positive for GBV-C RNA, and had an elevation in serum transaminase levels, whereas all the other GBV-C infected infants showed no evidence for hepatitis. A family study, performed on 2 of the 7 infected cases, revealed that all the elder siblings of the index infants were also GBV-C RNA-positive. Nucleotide sequence of GBV-C RNA, amplified by PCR from an NS3 region, was completely identical between the mother and the infant within each family, but varied significantly across different families. These results suggest that GBV-C is more easily transmitted from mother to infant than HCV, although hepatitis is not caused thereby.

Living related partial liver transplantation for primary biliary cirrhosis--a case report

An adult living related partial liver transplantation was performed on a 49 year old female with terminal hepatic failure due to primary biliary cirrhosis (PBC). The donor was her 53 year-old sister. A sufficient volume of graft tissue was obtained, which comprised 1.5% of the body weight of the recipient. The recipient had an excellent recovery without any major complications, and was discharged 35 days after the operation. At 15 months after the operation, the patient has shown no signs of rejection while using FK506 and prednisolone as immunosuppressants. The progression of symptomatic PBC can be predicted, and the timing of the transplantation can be easily determined. In addition, the results of liver transplantation for PBC are good. Therefore, adult living related partial liver transplantation is an excellent treatment for primary biliary cirrhosis.

Cloning, differential regulation and tissue distribution of alternatively spliced isoforms of ADP-ribosylation-factor-dependent phospholipase D from rat liver

An alternatively spliced isoform of ADP-ribosylation-factor-dependent phospholipase D (PLD1) was previously shown to occur in rat C6 cells [Yoshimura, Nakashima, Ohguchi, Sakai, Shinoda, Sakai and Nozawa (1996) Biochem. Biophys. Res. Commun. 225, 494-499] and human HeLa cells [Hammond, Jenco, Nakashima, Cadwallader, Gu, Cook, Nozawa, Prestwich, Frohman and Morris (1997) J. Biol. Chem. 272, 3860-3868]. However, its complete sequence and the enzymological difference between the two PLD1 isoforms were unclear. Here we report the cloning, complete sequence, enzymological properties and tissue distribution of each of the two alternatively spliced PLD1 isoforms, a and b, from rat liver. The major difference between the two isoforms was the deletion of 38 amino acids in the b isoform, but otherwise the two cDNA sequences were 99.9% identical. The a-isoform sequence was 91% identical with the a form of human PLD1, and the 38-amino-acid deletion in the b form occurred at the same site as in the b form of human PLD1. Both of the rat PLD1 isoforms expressed in the fission yeast Schizosaccharomyces pombe were dependent on ADP-ribosylation factor 1 and phosphatidylinositol 4,5-bisphosphate. The a isoform was activated by RhoA in a synergistic manner with ADP-ribosylation factor 1, whereas the b isoform was less responsive to RhoA. Reverse transcription PCR showed that the b form was the predominant PLD1 isoform expressed in rat tissues. The b-form transcript occurred in various rat tissues, including lung, brain, liver, kidney, small intestine and colon, whereas the a-form transcript was only detectable in lung, heart and spleen. Both transcripts were hardly detectable in thymus, stomach, testis and muscle. Thus the two PLD1 isoforms were differently regulated and expressed in rat tissues.

Influence of HLA haplotypes on the clinical courses of individuals infected with hepatitis C virus

The human leukocyte antigen is a crucial genetic factor that initiates or regulates immune response by presenting foreign or self antigens to T lymphocytes. The aim of this study was to investigate whether HLA polymorphism is associated with the onset or progression of liver injury in chronic hepatitis C virus (HCV) infection. We determined HLA class I antigens and class II alleles in 130 hepatitis C virus (HCV)-infected patients (33 carriers with persistently normal alanine transaminase [ALT] values and 97 patients with chronic liver disease [CLD]). HLA class I (A, B) was typed serologically, and class II (DRB1, DQB1) was typed by means of polymerase chain reaction-restriction fragment length polymorphism methods. The frequencies of DRB1*0405 and DQB1*0401 were higher in HCV-infected patients than in uninfected subjects. Among HCV-infected patients, the frequencies of B54, DRB1*0405, and DQB1*0401 were significantly higher in patients with CLD than in those carriers with persistently normal ALT values, whereas DRB1*1302, DRB1*1101, and DQB1*0604 were more frequently found in carriers with persistently normal ALT values than in patients with CLD. From extended haplotype analyses, in carriers with B54-DRB1*0405-DQB1*0401 haplotype, the risk of having liver injury was 13.2 times greater than in carriers with DRB1*0405-DQB1*0401 but without B54 [P = 0.0015, Haldane odds ratio = 13.2 (95% confidence interval, 1.7-103.8)]. In contrast, carriers with B44-DRB1*1302-DQB1*0604 had a 12.7-fold lower relative risk of developing liver injury compared to those with the haplotype containing B44 but not DRB1*1302-DQB1*0604 [P = 0.0076, Haldane odds ratio = 0.079 (0.009-0.695)]. Our findings show that extended haplotypes including class I B54 are closely associated with the progression of liver injury, whereas extended haplotypes including class II DRB1*1302-DQB1*0604 are associated with low hepatitis activity in chronic HCV infection.

Apoptotic cell death of cultured cerebral cortical neurons induced by withdrawal of astroglial trophic support

Peripheral neurons which depend on NGF for their survival undergo apoptosis after NGF deprivation. However, a convenient in vitro method for assessing the programmed cell death of the central neurons has not been established, because the dependence of particular central neurons on neurotrophic factors has been clarified only for small populations of neurons. Based on the fact that cortical neurons survive in culture for many weeks in the presence of astroglial cells, we have established an in vitro cell death model in which the neurons die through apoptosis. Cortical neurons were maintained on a cover slip for 1 week on top of astroglial cells, and then cell death was induced by separation of the neurons from the astroglial cells. The cortical neurons died within 2-4 days. Nuclei of the dying neurons showed the morphological features of apoptosis, and DNA fragmentation was observed by the TUNEL method and by in situ nick translation (ISNT) staining. The cell death was significantly suppressed by neurotrophic factors, NT-3, NT-4, BDNF, and GDNF, but not by NGF. The neuronal survival was prolonged, as in the case of peripheral neurons, by bFGF, elevated potassium, cAMP, forskolin, and metabotropic glutamate receptor agonist. The cell death was inhibited by inhibitors of interleukin-1 beta-converting enzyme and CPP32. CPP32-like proteolytic activity was increased prior to the appearance of apoptotic cells. These results suggest that cortical neurons die after separation from glial cells through apoptosis caused by deprivation of neurotrophic factors produced by the astroglial cells.