Novel factor highly conserved among eukaryotes controls sexual development in fission yeast

In the fission yeast Schizosaccharomyces pombe, the onset of sexual development is controlled mainly by two external signals, nutrient starvation and mating pheromone availability. We have isolated a novel gene named rcd1+ as a key factor required for nitrogen starvation-induced sexual development. rcd1+ encodes a 283-amino-acid protein with no particular motifs. However, genes highly homologous to rcd1+ (encoding amino acids with >70% identity) are present at least in budding yeasts, plants, nematodes, and humans. Cells with rcd1+ deleted are sterile if sexual development is induced by nitrogen starvation but fertile if it is induced by glucose starvation. This results largely from a defect in nitrogen starvation-invoked induction of ste11+, a key transcriptional factor gene required for the onset of sexual development. The striking conservation of the gene throughout eukaryotes may suggest the presence of an evolutionarily conserved differentiation controlling system.

Induction of asymmetrical type of chromosomal aberrations in cultured human lymphocytes by ion beams of different energies at varying LET from HIMAC and RRC

Frequencies of asymmetrical type of chromosome aberration were scored in cultured human blood lymphocytes irradiated with carbon and neon beams. Blood cells were irradiated with various doses to establish dose response curves for chromosome aberration frequency vs. dose, and chromosome preparation was made by conventional method. Dose response curves for the per cell frequencies of the dicentrics and centric rings as well as the excess amount of acentric fragments were described for 7 different qualities (LET = 22.4, 40.0, 41.5, 69.9, 70.0, 100.0 and 150 KeV/micrometer) of carbon and neon beams with three different energies, 135, 290 and 400 MeV/u. From the analysis of those dose response curves, the maximum effect was found in the region of LET value at near 70 KeV/micrometer together with linear expression in the response from all endpoints examined. The 135 MeV/u of carbons (69.9 KeV/micrometer) and neons(70.0 KeV/micrometer) showed linear response. The 290 MeV/u of carbons (100 KeV/m) and neons (150 KeV/micrometer) showed medium effects with different shape of response, linear with a plateau and upward concavity. The 2 carbon beams (41.5 and 40 KeV/micrometer) from 2 different accelerators showed much discrepancy in the response. RBE-LET relationship was also described by comparing the coefficient alpha of the 7 different dose responses. The peak (near 70 KeV/m) was localized close to that (80 KeV/m) for the survivals of dsb repair deficient cells (Eguchi-Kasai et al. 1998), but in different position from that previously reported in many other studies (100-200 KeV/mm). Identification of the RBEmax in the present study has yet to be definitive.

HRA Model for Hypercholesterolemia Based on a Longitudinal Health Database

To evaluate the risk factors for hypercholesterolemia, we examined 4,371 subjects (3,207 males and 1,164 females) who received medical checkups more than twice at an AMHTS in Tokyo during the period from 1976 through 1991; and whose serum total cholesterol was under 250 mg/dl. The mean follow-up duration was 6.6 years. A self-registering questionnaire was administered at the time of the health checkup. The endpoint of this study was the onset of hypercholesterolemia when the level of serum total cholesterol was 250 mg/dl and over. We compared two prognosis groups (normal and hypercholesterol) in terms of age, examination findings and lifestyle. After assessing each variable, we employed Cox's proportional hazards model analysis to determine the factors related to the occurrence of hypercholesterolemia. According to proportional hazards model analysis, total cholesterol, triglyceride and smoking at the beginning, and hypertension during the observation period were selected in males; and total cholesterol at the beginning and age were selected in females to determine the factors related to the occurrence of hypercholesterolemia.

Sequence of a melibiose transporter gene of Enterobacter cloacae

We cloned a fragment of the chromosomal DNA of Enterobacter cloacae, which enabled a melibiose-negative Escherichia coli mutant lacking melB to grow on melibiose as the sole source of carbon. Transformed cells harboring the hybrid plasmid carrying the cloned DNA showed melibiose transport activity. The nucleotide sequence of the DNA region was determined. One complete open reading frame (ORF) and a part of another ORF were found in the region, and the amino acid sequences were deduced. The complete ORF was found to encode a melibiose transporter which consisted of 425 amino acid residues. Hydropathy analysis revealed that there are about 12 hydrophobic domains in this transporter. The incomplete ORF which exists in the upstream region of the transporter gene seemed to encode an alpha-galactosidase.

Isoflurane inhibits endothelium-mediated nitric oxide relaxing pathways in the isolated perfused rabbit lung

PURPOSE

The role of volatile anaesthetics on nitric oxide (NO)-dependent relaxation is unclear in the pulmonary circulation. We examined the effects of isoflurane on NO-dependent relaxation in isolated perfused rabbit lungs.

METHODS

Eighteen rabbit lungs were perfused in a constant-flow recirculation manner. In study 1 (n = 12), acetylcholine (ACh, 4 x 10(-10)-10(-8) M) or nitroglycerine (NTG, 6 x 10(-10)-10(-8) M) was cumulatively injected into the pulmonary artery in the absence or presence of isoflurane (1, 2 MAC). In study 2 (n = 6), ACh was injected as in study 1 in the presence or absence of N omega-nitro-L-arginine methyl ester (L-NAME, 100 microM), an NO synthesis blocker. In all experiments, indomethacin was administered to prevent formation of vasoactive prostanoid metabolites, and the pulmonary vessels were preconstricted with prostaglandin F2 alpha (PGF2 alpha) infused before ACh or NTG injection. The ACh- or NTG-induced relaxation was expressed as % decrease in PGF2 alpha preconstriction.

RESULTS

Isoflurane at 2 MAC attenuated the dose-dependent relaxation to ACh at doses of 4 x 10(-9) M and 4 x 10(-8) M from 27.8 +/- 4.3% and 38.8 +/- 5.3% to 17.0 +/- 3.5% and 25.5 +/- 4.9%, respectively (P < 0.05). Isoflurane did not change the dose-dependent relaxation to NTG and L-NAME abolished the ACh-induced relaxation.

CONCLUSION

Isoflurane inhibited NO-dependent relaxation in the pulmonary circulation at a site distal to the endothelial cell receptor-mediated responses but proximal to guanylate cyclase activation of vascular smooth muscle. Acetylcholine-induced relaxation in isolated perfused rabbit lungs was regulated primarily by NO.

A melibiose transporter and an operon containing its gene in Enterobacter cloacae

We detected inducible melibiose transport activity in cells of Enterobacter cloacae IID977. H+, but not Na+, was found to be the coupling cation for this transporter. We cloned and sequenced the gene encoding the melibiose transporter. A homology search of a protein sequence database revealed that this melibiose transporter has high sequence similarity with the lactose transporter (LacY) and the raffinose transporter (RafB) and has some similarity with the melibiose transporter (MelB) of Escherichia coli.

Characteristics of the melibiose transporter and its primary structure in Enterobacter aerogenes

Cells of Enterobacter aerogenes can grow on melibiose as a sole source of carbon. This suggests the presence of melibiose operon in this organism. We found that E. aerogenes cells possess both alpha-galactosidase activity and melibiose transport activity, which were induced by melibiose. Neither Na+ nor Li+ stimulated the melibiose transport. However, transport of methyl-beta-thiogalactoside (TMG) was stimulated by Li+ but not by Na+. These findings suggest that the major coupling cation for the melibiose transporter in E. aerogenes is H+. In fact, we observed H+ entry into cells caused by an influx of melibiose and some of its analogs. We cloned the melB gene which encodes the melibiose transporter, and sequenced it. Deduced amino acid sequence of the transporter revealed that the melibiose transporter consists of 471 amino acid residues and the molecular weight was calculated to be 52214 Da. The sequence showed high homology with the sequences of the melibiose transporters of Escherichia coli, Salmonella typhimurium and Klebsiella pneumoniae. Higher homology was found with the melibiose transporter of K. pneumoniae than with that of E. coli and S. typhimurium.

[Studies on enrichment broth for verotoxin-producing Escherichia coli (VTEC) O157]

Growth of verotoxin-producing Escherichia coli (VTEC) O157 in conventionally recommended pre-enrichment broth media at different temperatures was evaluated. In addition, sensitivity of VTEC O157 isolates to several antibacterial drugs, which were added to the selective enrichment broth, was tested. All five isolates of VTEC O157 tested grew well in trypticase soy broth (TSB) at 36 degrees C and 42 degrees C, while the growth of one isolate was markedly suppressed in TSB supplemented with cefixime (CFIX), potassium tellurite (PT), and vancomycin (TSB-CTV) even at 36 degrees C. A significant growth suppression was also observed in three of the isolates cultured in novobiocin (NB)-supplemented modified EC broth (mEC-NB) at 42 degrees C. In mEC-NB after 24-hr incubation at 36 degrees C, the five VTEC O157 isolates grew well, although one isolate was slightly suppressed during the first 8 hours. Minimum growth inhibitory concentrations of CFIX, NB and PT for a total of 90 clinical and environmental isolates of VTEC O157 were all above the concentrations usually prescribed for mEC-NB and TSB-CTV. These findings suggest that mEC-NB and TSB-CTV should be used at 36 degrees C for growth of VTEC O157 and that use of a nonselective pre-enrichment broth medium (i.e. TSB) together with a selective one (i.e. TSB-CTV or mEC-NB) is necessary for successful isolation of VTEC O157 from various specimens.

Epidemiological study of Mycoplasma pneumoniae infections in japan based on PCR-restriction fragment length polymorphism of the P1 cytadhesin gene

Two hundred fifty strains of Mycoplasma pneumoniae isolated during the past 20 years in Japan were classified into two groups (I and II) based upon different PCR-restriction fragment length polymorphism patterns of their P1 cytadhesin genes. Clear shifts between the M. pneumoniae groups were observed but did not appear to be correlated with M. pneumoniae epidemic cycles. Patients' sera showed relatively higher levels of antiadhesin antibodies to M. pneumoniae strains homologous with the infecting strain.

Cloning and characterization of the Pichia pastoris PRC1 gene encoding carboxypeptidase Y

We purified a 58 kDa serine protease from culture-supernatant of Pichia pastoris and found that the NH2-terminal amino acid sequence of this protease is closely homologous to that of mature protein of Saccharomyces cerevisiae carboxypeptidase Y (CPY), which is encoded by the PRC1 gene. Using the S. cerevisiae PRC1 gene as a hybridization probe, a cross-hybridizing fragment of P. pastoris genomic DNA was identified and the gene, PRC1, encoding CPY, was cloned. The open reading frame of the P. pastoris PRC1 gene consists of 1569 bp encoding a protein of 523 amino acids. The molecular mass of the protein is calculated to be 59.44 kDa without sugar chains. The protein comprises 20 amino acids of pre (signal)-peptide, 87 amino acids of pro-peptide and 416 amino acids of mature peptide, and has four N-glycosylation sites. The NH2-terminal amino acid sequence of mature peptide is completely identical with that of the protease purified from the culture-supernatant. There is 61% identity between the amino acid sequences of P. pastoris Prc1p and S. cerevisiae Prc1p. Chromosomal disruption of the PRC1 gene resulted in the loss of CPY activity. Over-expression of the PRC1 gene under regulation of the P. pastoris AOX1 promoter resulted in accumulation of a large amount of active CPY in the intracellular fraction, and secretion of a slightly larger molecule that is thought to be pro-CPY. The nucleotide sequence data reported in this paper will appear in the EMBL Nucleotide Sequence Databases under the Accession Number X87987.

[Detection of Mycoplasma pneumoniae from throat swab by polymerase chain reaction]

Polymerase chain reaction (PCR) with primers directed against the 16S-rRNA gene of Mycoplasma pneumoniae was used to diagnose M. pneumoniae infections, and the results were compared with those of culture and serology methods. Eighty (22%) of 363 throat swab samples from patients with acute respiratory complaints gave positive results by using the PCR method. Sixty-seven (18.5%) of the samples were positive in culture method. Of 35 samples which were unreliable culture results due to contamination with other bacteria, 13 gave positive results in the PCR method. Of the 97 cases obtained throat swabs and paired sera, 28 (28.9%) showed positive results by the PCR assay, and 29 (29.9%) by serology method (particle agglutination test). The positive rate was increased to 36% by using both the PCR and the serology methods. From these results it was concluded that the PCR method is useful for laboratory diagnosis of M. pneumoniae infections.

[Inhibition of pulmonary vasoconstriction by inhaled nitric oxide]

We examined effects of inhaled NO gas on pulmonary vasoconstriction induced with hypoxic gas or PGF2 alpha utilizing the isolated perfused rabbit lung. While NO 180 ppm did not change the basal pulmonary artery pressure, the pressure response to hypoxia or PGF2 alpha was completely inhibited by pretreatment with NO inhalation. Inhaled NO during maximal pressor response also depressed the elevated pressure to the basal level. These findings suggest that NO inhaled to the alveoli diffuses directly into the pulmonary vascular smooth muscle and then causes nonspecific vasodilation, and its effect is more potent than that of constitutive type of EDRF/NO.

[Alcohol beverage advertisements--survey of weekly magazines]

This paper presents an analysis of alcohol beverage advertisements appearing in weekly magazines and comics. Few studies have be undertaken on this sector of the mass media in Japan. The results are compared with those of a similar study in the United States. We also review alcohol advertisements on television and the drinking scenes shown in comics. On the average, Japanese magazines tend to contain fewer alcohol advertisements than American magazines. However, 18 (53%) in 34 weekly magazines contained alcohol advertisements showing that such magazines are an important medium for alcoholic beverage advertising in Japan. There were also alcohol advertisements targeting to particular populations, youths and women, which may be connected with the increase in drinking in these groups. Alcohol advertisements in the mass media should be monitored continuously as public health issue.

Radiotherapy for hepatocellular carcinoma: clinicopathological study of seven autopsy cases

The clinical value of radiotherapy for hepatocellular carcinoma (total tumor dose: 50-70 Gy) was evaluated in seven autopsied patients with nine tumors. A partial response as defined by the WHO criteria for chemotherapy was observed in three tumors (33%). Progressive and marked shrinkage of the noncancerous liver tissue within the irradiated field was also observed in all cases. Histological examination revealed viable cancer cells in all cases. These results indicate that local radiotherapy applying 50-70 Gy achieved some clinical benefit, but was not capable of curing hepatocellular carcinoma.

Cloning and sequencing of the gene for the lactose carrier of Citrobacter freundii

The gene coding for the lactose carrier of Citrobacter freundii was cloned into the plasmid pBR322. The gene was sequenced and the amino acid sequence was found to be 70% identical to the lactose carrier of E. coli. All of the charged residues in the membrane spanning region were conserved. The sugar specificity is somewhat different from that of E. coli. The C. freundii carrier has less activity for lactose and more activity for o-nitrophenyl-galactose (ONPG) than the carrier of E. coli.

Hyperresponsiveness of cardiac muscles to histamine in reserpine-treated guinea pigs

The hyperresponsiveness of cardiac tissue to histamine following treatment with reserpine was pharmacologically characterized. Guinea pig hearts were isolated 24 hours after intraperitoneal administration of 5 mg/kg reserpine. This treatment resulted in a complete depletion of tissue norepinephrine. Reserpine treatment potentiated the positive inotropic response of isolated perfused hearts to histamine at doses ranging from 0.3 to 3 micrograms (23 to 57% increase for reserpine-treated animals vs. 14 to 32% increase for control animals). Isolated left ventricular papillary muscle of reserpine-treated guinea pig hearts also showed hyperresponsiveness to histamine at concentrations of 0.1 microM or greater. The hyperresponsiveness of the papillary muscle contraction of the reserpine-treated animals to histamine was abolished in the presence of 1 microM cimetidine, but not attenuated in the presence of 1 microM diphenhydramine. This hyperresponsiveness was not modified by 1 microM bunazosin or 1 microM propranolol. The results suggest that H2-receptor mediated action plays a role in the hyperresponsiveness of cardiac muscles to histamine.

Characterization of the lactose transport system in Citrobacter freundii

The lactose transport system of Citrobacter freundii was characterized. Both the lactose transport system and beta-galactosidase were induced with either lactose or isopropyl-beta-D-thiogalactopyranoside (IPTG), the latter being the better inducer. The Km values for methyl-beta-D-thiogalactopyranoside (TMG) transport and lactose transport were 0.61 mM and 1.1 mM, respectively, and the Vmax values were 53 nmol/min/mg cell protein and 12 nmol/min/mg cell protein, respectively. Thus, TMG is a better substrate than lactose. Thiogalactopyranoside (TDG) was a very potent competitive inhibitor. Neither Na+ nor Li+ had a significant effect on the TMG transport or the lactose transport. Proton/substrate cotransport (symport) via this system was observed.

Radiological study of idiopathic Budd-Chiari syndrome complicated by hepatocellular carcinoma. A report of four cases

During an 11-yr period (1979-1989), we have experienced five patients with idiopathic Budd-Chiari syndrome (BCS), four (80%) of whom had associated hepatocellular carcinoma (HCC). In contrast, the incidence of BCS complicated by HCC was 0.7% of a total of 556 patients who underwent surgery for HCC or were autopsied. Hepatitis B virus-related antigen or antibody was positive in one patient each. Four of our five patients were asymptomatic and were initially diagnosed by ultrasonography (n = 3) or computed tomography (n = 1). The hepatic parenchyma histopathological findings were cirrhosis and fibrosis in one each. Infection of hepatitis B virus rather than BCS was speculated as a causative factor for HCC in two patients. Membranous obstruction with spotty calcification, intrahepatic bizarre communicating vessels, and the dilated anterior longitudinal veins in spinal canal were recognized in three patients. Three patients had two HCCs which were similar in size and arose from the right and left hepatic lobe, separately, suggesting multicentricity of HCC. Both percutaneous transluminal angioplasty with Gruntzig balloon catheters for the obstruction of the inferior vena cava and hepatic arterial embolization for HCC(s) were performed in three patients. These patients survived 29.3 months on average after the diagnosis of BCS complicated by HCC(s). The opened IVC was confirmed to be patent on an average of 26.3 months after the first angioplasty.

Leiomyosarcoma of the pancreas: report of a case diagnosed by fine needle aspiration biopsy

We present a case of pancreatic leiomyosarcoma with liver metastasis diagnosed by liver tumor biopsy. A 66-year-old man had a pancreatic tumor and hepatic tumors, which were hypoechoic and mixed echoic on ultrasonography, respectively. They were stained in enhanced computed tomography and angiography. A fine needle aspiration biopsy of the liver tumor was performed, and the pathological examination of the biopsied specimen suggested the tumor cells to have originated from smooth muscle. Under a diagnosis of pancreatic leiomyosarcoma with liver metastasis, the patient was treated with several anticancer agents. The tumor, however, spread to multiple organs and he dies of the disease two years nine months after the start of treatment. The diagnosis of pancreatic leiomyosarcoma was confirmed by autopsy.

[Comparative study of health problems between wives of alcoholics and control wives]

This study involves an the analysis of health problems and psychosomatic disorders between wives of alcoholics and those of non-alcoholics. The subjects of the study were 122 wives of alcoholics who accompanied their husbands for outpatient alcoholism treatment at Kurihama National Hospital. For an appropriate comparison, 88 aged-matched wives of non-alcoholic husbands were asked to cooperate as controls. The subjects were given Cornell Medical Index (CMI) and our original questionnaire on their own and their husbands' health problems on their first outpatient visit. The controls were also given them during the same research period. The results are briefly summarized as follows: 1. The most obvious health problem of wives of alcoholics with an incidence significantly higher than that of wives of non-alcoholics was genital disease; 13.9% of the subjects had such diseases, in contrast to 1.1% of the controls. 2. The second health problem of the subjects which significantly exceeded that of the controls was cardiovascular disease (9.0% vs 1.1%). 3. The mean number of past illnesses of the subjects was 0.78 (SD 1.08) compared with 0.51 (SD 0.82) for the controls. 4. The rate of current illness of the subjects was 28.2% compared with 19.3% for the controls. 5. The rate of CMI Category IV (indicates "neurotic") of the subjects was 5.0% compared with 0.0% for the controls. 6. As a whole, our results were more moderate than those of previous studies, but wives of alcoholics had more current and past illness, and were more neurotic than the controls.

Liver abscess after percutaneous ethanol injection (PEI) therapy for hepatocellular carcinoma. A case report

We present a case of liver abscess after percutaneous ethanol injection (PEI) therapy for the treatment of recurrent hepatocellular carcinoma (HCC). The 56-year-old woman had a past history of cholecystoduodenostomy for cogenital dilatation of the bile duct, and pneumobilia was observed in the intrahepatic bile ducts prior to PEI. The abscess was successfully treated by percutaneous abscess drainage and antibiotic therapy. Klebsiella pneumonia, one of the most common causative organisms of biliary tract infection, was isolated from the abscess. Thus, biliary tract infection related to the previous biliary-enteric anastomosis operation may have been one of the causative factors in the liver abscess in this patient. The rare experience reported here suggests that a careful search for coexistent abscess at the time of PEI is important in HCC patients with biliary-enteric anastomosis, especially in those with pneumobilia.

Follow-up examination schedule of postoperative HCC patients based on tumor volume doubling time

The tumor volume doubling time of 27 recurrent hepatocellular carcinoma nodules measuring < or = 2.0 cm in diameter discovered after hepatectomy in 19 patients was analyzed by ultrasonography for 31 to 331 days. The tumor volume doubling time ranged from 39 to 420 days before specific treatment, with a mean of 112 days and a median of 80 days. It correlated with age and intrahepatic site of recurrence, which was sometimes the same lobe as that of the prior hepatocellular carcinoma, sometimes not. The tumor volume doubling time also tended to correlate with hepatitis C antibody status and initial tumor diameter. The tumor volume doubling time was, however, independent of sex, hepatitis B surface antigen status, number of recurrent tumors, initial serum alpha-fetoprotein level, interval between hepatectomy and recurrence detection, and associated liver disease. On the basis of the shortest tumor volume doubling time of the recurrent hepatocellular carcinoma nodules, we recommend that US and/or CT be performed at least every four months to screen for small recurrent carcinomas in postoperative patients.

[Immobilization of a sensitive plant, Mimosa pudica L., by volatile anesthetics]

The disappearance of thigmonastic mobility of a sensitive plant, Mimosa pudica L., caused by volatile anesthetic agents such as methoxyflurane, chloroform, halothane, enflurane or sevoflurane revealed that the response to anesthetic agents in plants maybe similar to that in animals. In terms of reversible anesthesia, animals seem to equal plants in order of potency of anesthetics, and the minimum immobilizing concentration (MIC; %) in the plant shows a good correlation with MAC in the human (MICplant = 5.8 MAChuman + 0.01, r2 = 0.946). These phenomena suggest the existence of a certain common mechanism in anesthesia between animals and plants.

Semiautomated 14C-thymidine incorporation assay for in vitro screening of anticancer drug

We developed a rapid screening test for anticancer drugs by using 14C-thymidine (14C-TdR), a microculture filtration plate and a radiochromatoscanner. Mitomycin C (MMC), tamoxifen and 5-fluorouracil (5FU) were used as the anticancer drugs against four human gastric cancer cell lines. The rates of cell inactivation (14C-TdR uptake) determined with the radiochromatoscanner were almost the same as those determined with the liquid scintillation counter. Comparing the rate of cell inactivation obtained by our method with that obtained by proliferative activity of cells derived from the cell count, both assays showed the approximately same results by tamoxifen and MMC but the rates of cell inactivation by 5FU in two cell lines obtained by the 14C-TdR uptake assay was considerably lower than those obtained by the cell count. These results show that the radio-labeled DNA precursor uptake assay is not suitable for metabolic inhibitors of DNA synthesis. Ninety six samples on a plate, however, were assayed semiautomatically and rapidly just as well as in the tetrazolium-based calorimetric (MTT) assay. Therefore, our 14C-TdR uptake assay system is useful for the cancer chemotherapeutic agents except the metabolic inhibitors of DNA precursors.

Health-risk appraisal applied to ordinary AMHTS

The main purpose of an automatic health testing system (AMHTS) has changed from early detection to primary prevention. Health-risk appraisal is now widely available as a tool of health education aiming at the modification of unhealthy lifestyles. However, the opportunity to offer appropriate health education was less frequent for those who had no particular findings during AMHTS. The results of an AMHTS should be evaluated from the viewpoint of health-risk appraisal, because the system is expected to supply useful information regarding one's lifestyle. Our system consists of two health-risk appraisal subsystems. One subsystem estimates the degree of improvement in medical indicators after a patient's lifestyle has been modified. The other subsystem predicts the occurrence of abnormal findings in medical indicators. These health-risk appraisal subsystems provide patients with information about their health-risks, based on their AMHTS results. Our health-risk appraisal subsystems should play an important role in future health education through the application of ordinary AMHTS.

Hepatocellular carcinoma with portal tumor thrombus: analysis of factors determining prognosis

For 104 consecutive patients with hepatocellular carcinoma (HCC) with portal tumor thrombus (PTT) seen in the past nine years, prognostic factors were analyzed retrospectively using Cox's multivariate analysis. There was a significant difference in survival rate with hepatic functional reserve (Child classification, P = 0.005), type of treatment (surgical vs non-surgical treatment, P = 0.009) and PTT grade (P = 0.04). The survival rates for patients with Child's A (n 49) or Child's B (n 55) were 60.8 vs 20.0% at one year, 41.6 vs 9.1% at two years and 35.4 vs 5.5% at three years. The survival rates of patients with surgical (n 32) and non-surgical (n 72) therapy were 71.7 vs 25.0% at one year, 58.5 vs 9.4% at two years and 53.6 vs 4.7% at three years. Among patients with PTT grades in the third or lower order branch (Vp1, n 29), the second order branch (Vp2, n 32) and the first or portal vein trunk (Vp3, n 43), the one-year, two-year and three-year survival rates were 61.6, 43.8 and 20.9%; 47.1, 27.5 and 6.2% and 42.8, 27.5 and 0%, respectively. When analysis was focused on 32 patients with Child's A and PTT (Vp1 plus Vp2) with respect to treatment, the survival rates in the surgical (n 22) and nonsurgical (n 10) groups were 86.1 vs 70.0% at one year, 71.5 vs 30.0% at two years and 64.3 vs 20.0% at three years (P < 0.05), respectively. In HCC patients with PTT, surgery seems to be indicated where hepatic function is well preserved and the PTT is localized in a peripheral portal branch.

Conversion of the Salmonella phase 1 flagellin gene fliC to the phase 2 gene fljB on the Escherichia coli K-12 chromosome

The Escherichia coli-Salmonella typhimurium-Salmonella abortus-equi hybrid strain EJ1420 has the two Salmonella flagellin genes fliC (antigenic determinant i) and fljB (determinant e,n,x) at the same loci as in the Salmonella strains and constitutively expresses the fliC gene because of mutations in the genes mediating phase variation. Selection for motility in semisolid medium containing anti-i flagellum serum yielded 11 motile mutants, which had the active fliC(e,n,x) and silent fljB(e,n,x) genes. Genetic analysis and Southern hybridization indicated that they had mutations only in the fliC gene, not in the fljB gene or the control elements for phase variation. Nucleotide sequence analysis of the fliC(e,n,x) genes from four representative mutants showed that the minimum 38% (565 bp) and maximum 68% (1,013 bp) sequences of the fliC(i) gene are replaced with the corresponding sequences of the fljB(e,n,x) gene. One of the conversion endpoints between the two genes lies somewhere in the 204-bp homologous sequence in the 5' constant region, and the other lies in the short homologous sequence of 6, 8, or 38 bp in the 3' constant region. The conversions include the whole central variable region of the fljB gene, resulting in fliC(e,n,x) genes with the same number of nucleotides (1,503 bp) as the fljB gene. We discuss the mechanisms for gene conversion between the two genes and also some intriguing aspects of flagellar antigenic specificities in various Salmonella serovars from the viewpoint of gene conversion.

A phase 2 study of cisplatin in patients with hepatocellular carcinoma

A phase 2 study of cisplatin was performed in 28 previously untreated patients with unresectable hepatocellular carcinoma. The drug was given intravenously at a dose of 80 mg/m2/day every 4 weeks. Of 26 patients evaluated, 4 (15.4%) showed partial responses lasting for > 3 months, while no patient achieved a complete response. Of 22 patients whose serum level of alpha-fetoprotein (AFP) was high (> 400 ng/ml) before treatment, 6 (27.3%) showed a > 50% reduction in serum AFP levels after treatment. The current study indicates that cisplatin is an anticancer agent worthy of further testing in patients with this disease.

A new cdc gene required for S phase entry of Schizosaccharomyces pombe encodes a protein similar to the cdc 10+ and SWI4 gene products

We have isolated a new cell division cycle gene (res1+) required for entry into S phase, as a multicopy dual suppressor of the pat1 and cdc10 mutants of the fission yeast Schizosaccharomyces pombe. The res1+ gene specifies a 72 kDa protein with two copies of the cdc10/SWI6 motif. A disruptant of res1+ grows poorly at 30 degrees C with severe heat- and cold-sensitivities, and completely arrests in G1 at 36 degrees C and 23 degrees C. The arrested disruptant retains a full conjugation ability. In addition to the cdc10/SWI6 motif, Res1 and SWI4 proteins share a remarkable homology in their amino-terminal region, whereas Cdc10 and SWI6 do so in their carboxy-terminal region. Moreover, the amino-terminal region is essential for the function of Res1 as it is for the function of SWI4. Furthermore, analogous to the relationship of SWI4 to SWI6, the res1+ gene effectively rescues cdc10 mutants, but the cdc10+ gene cannot rescue the res1- phenotype. Thus, striking similarities exist in both structural and functional relationships between Res1 and SWI4, and between Cdc10 and SWI6. In view of the fact that SWI4 and SWI6 form a transcription factor complex and activate promoters containing the SWI4/SWI6 dependent cell-cycle box, Res1 might be a putative association partner of Cdc10 which appears to be involved at least in the activation of promoters containing a MluI cell-cycle box.

Postresection recurrence of hepatocellular carcinoma treated by arterial embolization: analysis of prognostic factors

Of 270 consecutive patients with hepatocellular carcinoma who underwent surgery, 50 who had recurrence and were subsequently treated with transcatheter arterial embolization were analyzed. The longest interval between surgery and recurrence in the 50 patients who underwent transcatheter arterial embolization was 7 yr. Recurrence was initially found in the remnant liver in all patients but one; extrahepatic metastases were detected in 13 patients (26%) during follow-up. A "multiple" type was the most common (64%) hepatic recurrence pattern on angiography, followed by the "solitary" (16%) and "tumor thrombus" (12%) patterns. Hepatic recurrence was most frequently found in the ipsilateral lobe (48%) relative to the site of the primary hepatocellular carcinoma. Multivariate analysis of the factors affecting survival after transcatheter arterial embolization indicated that recurrence pattern (p = 0.025) and distant metastases (p = 0.011) were significant. Of 13 patients with distant metastases, 11 had the "multiple" pattern of hepatic recurrence. Survival rates for all 50 patients after initial surgery and after transcatheter arterial embolization were 90% and 64%, respectively, at 1 yr; 52% and 24%, respectively, at 3 yr; and 27% and 5%, respectively, at 5 yr. On analysis of survival rates after transcatheter arterial embolization in 37 patients with recurrence only in the liver and of the response of recurrent hepatocellular carcinoma to transcatheter arterial embolization, a significant difference was noted between those with "partial response" and "progressive disease" (p less than 0.05) and between those with "no change" and "progressive disease" (p less than 0.05).

Prognostic factors in patients with hepatocellular carcinoma receiving systemic chemotherapy

A total of 71 consecutive patients with unresectable hepatocellular carcinoma were analyzed retrospectively to determine the significant prognostic factors. All the patients received systemic chemotherapy in a phase 2 study from 1980 to 1990, with no other anticancer treatment. Median survival time and 1-yr and 2-yr survival rates were 5.6 mo, 23% and 5%, respectively. By the univariate analysis, a performance status of 0-1 and tumor size less than 50% of the liver cross-sectional area were shown to be the factors most significantly favoring a better prognosis. By the multivariate analysis using the Cox proportional hazards model, a performance status of 0-1 (p less than 0.001), absence of tumor thrombus in the main portal trunk (p = 0.003) and age less than 60 yr (p = 0.036) were independent favorable prognostic factors. A prognostic index was calculated from these three factors according to the following equation: 1.8109 x (0 = performance status of 0-1 and 1 = performance status of 2-3) + 0.9322 x (0 = tumor thrombus absent in the main portal trunk and 1 = present) + 0.6996 x (0 = age less than 60 yr and 1 = age greater than or equal to 60 yr). This index was used to classify the patients into three groups with a good, intermediate and poor prognosis. The median survival times for these three groups were 9.8, 3.8 and 1.9 mo, respectively (p less than 0.01). The results of this study may be useful in the design and analysis of future clinical trials of systemic therapy for hepatocellular carcinoma.

Radiotherapy for bone metastases of hepatocellular carcinoma

Radiotherapeutic effects of 42 bone metastases in 26 hepatocellular carcinoma patients were retrospectively analyzed. Pain relief was observed in 79% of 37 bone metastases treated (29/37). Antitumor effects and improvement of paralysis were also observed in 88% (8/9) and 17% (1/6), respectively. The toxicities experienced were tolerable. Radiotherapy was an effective means of palliation in the treatment of hepatocellular carcinoma bone metastases.

A rapid anticancer drug screening assay by [14C] thymidine uptake in cultured human cancer cells

A rapid screening test by suppression of DNA synthesis in cancer cells was developed with [methyl-14C]-thymidine (14C-TdR), a microculture filtration plate and a radiochromatoscanner. Mitomycin, tamoxifen and 5-fluorouracil (5-FU) were tested against four human gastric cancer cell lines and HeLa cells. The tetrazolium-based colorimetric (MTT) assay underestimated cell inactivation by mitomycin in three cell lines compared with the cell count and the 14C-TdR assays. Inactivation by 5-FU in one cell line by 14C-TdR uptake was considerably lower than that by other methods. Thus neither the radio-labelled DNA precursor uptake nor the MTT assay is suitable for every anticancer drug but they are complementary.

The ste4+ gene, essential for sexual differentiation of Schizosaccharomyces pombe, encodes a protein with a leucine zipper motif

Ste4- mutants of Schizosaccharomyces pombe are unable to undergo both mating and meiosis. We have cloned the ste4+ gene and its cDNA. The gene encodes a 264 amino acid protein with a typical leucine zipper motif homologous with the jun family. However, unlike the jun family, this protein does not have a typical basic region that precedes the leucine zipper. The transcription of this gene absolutely depends on the ste11+ gene and increases several fold upon nitrogen starvation, a general signal for sexual differentiation. Whereas ste4+ is essential for mating and meiosis, its overexpression inhibits these processes.

A sensitive method for detecting the fermentation-inhibition antibody to Mycoplasma pneumoniae

The fermentation-inhibition (FI) test for Mycoplasma pneumoniae was improved by using a combination of guinea pig complement and gamma globulin-depleted horse serum in place of unheated whole horse serum employed in the conventional assay system. As the test antigen for the new FI assay system, M. pneumoniae filtrated through a 3.0 microns membrane filter was used. Owing to the strong augmenting effect of guinea pig complement, the FI activity of rabbit immune serum was increased 32-fold in the new system compared with the conventional system. Furthermore, IgM antibody, which is barely detectable by the conventional system, could easily be titrated by the new system. With this sensitive method, rapid rise of FI titer was clearly demonstrable in most children with acute M. pneumoniae infections, and a prevalence of FI or growth-inhibitory antibody among healthy adults in Japan (82%) was revealed.

Detection of hepatitis C virus infection by enzyme-linked immunosorbent assay system using core protein expressed in Escherichia coli

Enzyme-linked immunosorbent assay of the core protein of hepatitis C virus (HCV) expressed in E. coli led to detection of the antibody against this virus in patients with chronic hepatitis. Some of the negative results obtained using a different viral protein became positive with this E. coli-expressed viral protein, and were also positive for the viral RNA. Thus, use of the core protein of HCV facilitates accurate detection of HCV infection.

[The suppressive effects of smoking on antibody production in experimental hypersensitivity pneumonitis in rabbits]

Farmer's lung disease is one type of hypersensitivity pneumonitis (HP) in dairy farmers, and is usually caused by Micropolyspora faeni (Mf). It has been reported that the positive rate of precipitin antibody to Mf in smoking dairy farmers is one-eighth to one-half of that in nonsmoking dairy farmers. To clarify the mechanism of this phenomenon, by using an experimental HP model in rabbits, we investigated 1) the effects of short (5 weeks) and long (20 weeks)-term cigarette smoke exposure on the antibody formation, 2) the effects of 30 weeks of smoke exposure on the accessory cell function of alveolar macrophages (AM). Smoking exerted variable influences on antibody production, depending on the duration of smoke exposure, and we confirmed that long-term smoke exposure had suppressive effects. In addition AM from smoked rabbits suppressed lymphoproliferative response to autologous spleen cells. It was concluded that in this experimental HP, smoking affects the functions of both AM and lymphocytes, and that it suppresses antibody production as long as the smoke exposure continues.