[The graft replacement of the patient with aortic arch aneurysm and thrombosed aortic dissection]

The patient was male and aged 68 years and complained of dyspnea and chest pain. He was pointed out aortic arch dilatation on chest X-ray and CT demonstrated aortic arch aneurysm accompanied with acute type IIIb aortic dissection. One month later after anti-hypertensive therapy, the false lumen of aortic dissection was closed with thrombus. While we performed the graft replacement to the aortic arch aneurysm, the thrombosed false lumen was recanalized, so it needed the closure of the false lumen reinforced with teflon felt. Postoperative angiography showed no abnormality of anastomosis and complete occlusion of the false lumen.

The effect of acetazolamide and carbon dioxide on cerebral hemodynamic changes on near-infrared spectroscopy in young rabbits

The changes of cerebral blood oxyhemoglobin (HbO2), deoxyhemoglobin (HbR), and total hemoglobin (tHb) induced by acetazolamide and CO2 loading on near-infrared spectroscopy (NIRS) were recorded. In anesthetized 2-week-old rabbits, acetazolamide (10 mg/kg i.v.) increased HbO2 and tHb, concomitant with an increase in tissue PCO2, and decreased HbR only at 5 and 10 min. CO2 loading significantly increased HbR and decreased HbO2, and after the termination of CO2 loading, tHb and HbO2 significantly increased and HbR decreased to nearly the baseline value. Thus, NIRS demonstrated cerebral hemodynamic responses as a function of vasomotor reactivity to acetazolamide as well as CO2 loading.

Germ line chimera produced by transfer of cultured chick primordial germ cells

Intrinsic primordial germ cells (PGCs) from stage 27 (5-day-old) chick embryonic germinal ridges were cultured in vitro for a further 5 days, and shown to proliferate on stroma cells derived from the germinal ridge. To determine whether these cultured PGCs could colonize and contribute to the germ-line, PGCs were isolated by gentle pipetting, labeled with PKH26 fluorescent dye and injected into the blood stream of stage 17 (2.5-day-old) chick embryos. The recipient embryos were incubated until they reached stage 28. Thin sections of these embryos were analysed by fluorescent confocal laser microscopy. These analyses showed that the labeled donor PGCs had migrated into the germinal ridges of the recipient embryos, and transplanted PGCs had undergone at least 3-7 divisions. These results suggest that PGCs that had passed far beyond the migration stage in vivo were still able to migrate, colonize and proliferate in recipient chick embryonic gonads.

Development of an electrohydraulic total artificial heart at the National Cardiovascular Center, Osaka, Japan

The authors have been developing an electrohydraulic total artificial heart with a basic concept placing the blood pumps and an electrohydraulic energy converter separately, in the thorax and the abdominal region, respectively, to minimize anatomic constraints. Major problems of the system were a high energy consumption of 56 W at 6 L/min output and an insufficient maximum output of 6.7 L/min. The energy converter was redesigned to overcome these problems. A three phase, 4 pole brushless DC motor, which has maximum efficiency of 79% at a motor rotation of 2500 rpm with a load of 0.1 Nm, was developed for the new energy converter. Flow-channel design of the regenerative oil pump was optimized, which resulted in increasing the maximum flow rate at one directional motor rotation from 18 to 29 L/min. In vitro performance of the electrohydraulic total artificial heart was evaluated in a mock circulation with physiologic pressure conditions. Maximum output was increased to 10.7 L/min at a pump rate of 120 bpm and energy consumption of the motor at 6 L/min output was reduced to 18 W. Based upon these favorable results, the system is now being assembled for chronic animal implantation.

[Low incidence of point mutation of N-ras oncogene in human gliomas]

We examined the incidence of point mutations in codon 12 and 61 of N-ras gene in human gliomas using PCR with mismatched primers. This method detects point mutations. PCR with mismatched primers induced restriction sites in normal DNA but not in mutational DNA. Genomic DNAs were extracted from paraffin-embedded tissues and were amplified with nested PCR. Among 17 cases, point mutation has not been able to be found so far, when examined in codon 12 of N-ras gene and among 10 cases in codon 61 of N-ras gene. It can thus be said that point mutational activation of N-ras oncogene is an uncommon event in human gliomas.

Photodegradation kinetics of the new antibacterial fluoroquinolone derivative, orbifloxacin, in aqueous solution

The photodegradation kinetics of orbifloxacin (1-cyclopropyl-5,6,8-trifluoro-1,4-dihydro-7-(cis-3,5-dimethyl-1-pipe raz inyl)-4-oxoquinoline-3-carboxylic acid) was investigated in aqueous solution at various pH values (1.2-12.5) and at an ionic strength of 0.5. The photodegradation experiments were performed using a fluorescent or a chemical lamp as a light source and the cumulative number of photons during exposure was determined by a ferrioxalate actinometer. It was found that the photodegradation of orbifloxacin followed apparent first-order kinetics under both types of artificial light. The photodegradation rates of orbifloxacin in a neutral medium were higher than those in acidic and alkaline media. Orbifloxacin was most unstable in solution at pH 7.4, and its degradation half-life was 0.9 h. Also, the log k-pH profile indicated that the photodegradation rate of orbifloxacin was related to the dissociation of the carboxylic and dimethylpiperazinyl groups and the main photo-labile species was the zwitterionic form. In addition, the photodegradation kinetics of the decarboxylated derivative of orbifloxacin in aqueous solution was investigated to determine the effect of the functional groups on the photodegradation of orbifloxacin.

Degradation kinetics of the new antibacterial fluoroquinolone derivative, orbifloxacin, in aqueous solution

The degradation kinetics of orbifloxacin [1-cyclopropyl-5,6,8-trifluoro-1,4-dihydro-7-(cis-3,5-dimethyl-1-pipe raz inyl)-4-oxoquinoline-3-carboxylic acid] was investigated as a function of pH (1.5-10.5), temperature (100-120 degrees C) and buffer concentration (0.05-0.2 M) by means of high-performance liquid chromatography. The degradation of orbifloxacin in aqueous solution followed apparent first-order kinetics under all experimental conditions. No appreciable effect of buffer on the degradation of orbifloxacin was observed for any of the buffer species used in this study. The log k-pH profiles indicated specific-acid and specific-base catalyses and there were inflection points near pH 6 and 9 corresponding to the pKa1 and pKa2 values. From the Arrhenius plots, the activation energies for k'H, k'H2O, kH2O, k"H2O and k"OH were found to be 31.9, 36.9, 23.5, 26.5 and 19.0 kcal/mol, respectively. Arrhenius data obtained from this study showed that the degradation of orbifloxacin at room temperature was negligible at all pH values studied conditions (pH 1.5-10.5).

[A cooperative late phase II trial of l-leucovorin and 5-fluorouracil in the treatment of advanced gastric cancer. l-Leucovorin and 5-FU Study Group (Japan Western Group)]

A multicenter cooperative study was conducted to evaluate the clinical efficacy of l-leucovorin (l-LV) and 5-fluorouracil (5-FU) treatment in 69 cases of advanced gastric cancer. l-LV was administered intravenously by a 2-hour infusion at a dosage of 250 mg/m2 and 5-FU at a dosage of 600 mg/m2, intravenously via bolus one hour after administration of l-LV had been started. The combination was given weekly for 6 weeks followed by a 2-week rest period. Patients were evaluated for response after the sixth dose. Nineteen PRs were noted in the 55 patients for an overall response rate of 34.5%. Median survival time was 190 days for eligible cases, and 448 days for PR cases. Age and performance status (PS) appeared to influence clinical response. Patients aged 49 years or younger showed a significantly higher PR rate than those aged 50 years or older. The PR rate was significantly higher in the patients of PS 0-1 than those of PS 2. Diarrhea and leukopenia were experienced in 46.7% and 65% of patients, respectively. Patients who had severe toxicities required discontinuity of treatment. After recovery, treatment was repeated. The clinical results are promising for patients with advanced gastric cancer, particularly middle-aged patients. However, whether the l-leucovorin and 5-FU combination therapy will ultimately produce superior results in middle-aged patients awaits the results of Phase III trials.

Loss of serum HCV RNA at week 4 of interferon-alpha therapy is associated with more favorable long-term response in patients with chronic hepatitis C

To determine the virological factors associated with a favorable long-term response to interferon-alpha (IFN) therapy in chronic hepatitis C virus (HCV) infection, 61 Japanese patients with chronic HCV infection were treated with IFN for 24 weeks (780 million units in total) and followed for 8 to 16 months after cessation of therapy. Ten patients dropped out because of severe side effects. Of the 51 patients who completed IFN therapy, 23 showed complete and sustained response (CR --> SR), 13 complete response with early relapse (CR --> Rel), and 15 no response to IFN (NR). For the pretreatment serum HCV RNA level, 20/23 who had CR --> SR had < 10(6) eq/ml compared to 3/13 CR --> Rel and 1/15 NR (P < 0.01). Serologically defined HCV type 2 infection was also associated with a better opportunity to develop CR --> SR compared to CR --> Rel of NR (P < 0.01). Loss of serum HCV RNA at week 4 of IFN therapy was also associated with a more favorable long-term response [17/19 CR --> SR were HCV RNA negative compared to 3/11 CR --> Rel (P < 0.01) and 2/13 NR (P < 0.01)]. In contrast, normalization of serum alanine aminotransferase (ALT) levels at week 4 was found in 9/19 CR --> SR compared to 8/11 CR --> Rel (P = NS), and 0/13 in NR (P < 0.01). Six months after cessation of IFN therapy, 3/25 CR --> SR patients were HCV RNA positive despite normalization of serum ALT levels. These data indicated that in addition to pretreatment serum HCV RNA levels and HCV type, the kinetics of response to IFN (at week 4) were also predictive of subsequent long-term response to IFN in patients with chronic HCV infection.

Classification of hepatitis C virus into major types and subtypes based on molecular evolutionary analysis

Molecular evolutionary analysis was applied to determine the number of hepatitis C virus (HCV) types and subtypes based on all the HCV nucleotide sequences available from the DNA data banks (DDBJ, GenBank (NCBI), EMBL) and the literature. There was an excellent concordance among the types and subtypes assigned based on different HCV genomic regions. Only one HCV isolate was assigned to different HCV types based on the 5' non-coding (NC) and envelope 1 (E1) regions. The 5' NC region was well conserved and could be used to assign only types and not subtypes. From the sequence data available there were 13 subtypes based on the core region and 14 subtypes based on the E1 and non-structural protein 5 (NS5) regions.

Genotype distribution in Nagoya and new genotype (genotype 3a) in Japanese patients with hepatitis C virus

We evaluated hepatitis C virus (HCV) genotype distribution among Japanese patients in the city of Nagoya and the possible existence of any other genotype not determined by Okamoto's method. Eighty-five of 93 (91.4%) anti-HCV-positive patients had detectable HCV RNA. The genotype of the HCV isolate was determined in 84 of 85 (98.8%) of these HCV RNA-positive patients by Okamoto's method but determination was not possible in one (1.2%). Genotype 1b was detected in 58 of the 85 patients (68.2%), genotype 2a in 20 (23.5%), genotype 2b in 3 (3.5%), and genotype 1b + 2a in 3 (3.5%). In the remaining 1 patient in whom the genotype could not be determined, we determined the nucleotide sequence of the core region in HCV RNA extracted from this patient and evaluated it by molecular evolutionary analysis. This HCV isolate was then classified as genotype 3a. These results suggest that genotype 3a is rare among Japanese patients with HCV; thus, when classifying Japanese isolates, we should take more care because genotype 3a is not determined by current typing systems.

[Hemodynamic and neurohumoral effects of carperitide (alpha-human atrial natriuretic peptide) in dogs with low-output heart failure]

We examined the hemodynamic and neurohumoral effects of carperitide in dogs with low-output heart failure (LHF) produced by volume expansion, ligation of the left anterior descending coronary artery and methoxamine infusion. Carperitide (0.1 approximately 1 micrograms/kg/min, i.v. infusion for 30 min) decreased pulmonary arterial pressure, right atrial pressure and systemic vascular resistance and increased cardiac output. These pharmacological activities were equivalent to those of nitroglycerin (NG, 3 micrograms/kg/min). Although most of the animals did not excrete urine after induction of LHF, carperitide, unlike NG, increased urine volume. The plasma level of cyclic GMP was elevated about three times by induction of LHF and further increased after treatment with carperitide (1 microgram/kg/min). Carperitide had no effects on plasma renin activity, plasma aldosterone concentration and plasma noradrenaline. These results taken together indicate that carperitide reduces both preload and afterload in association with an increase in cyclic GMP production and improves the untoward hemodynamic alterations in LHF dogs.

[A comparative study of tazobactam/piperacillin and piperacillin in bacterial pneumonia]

The efficacy, safety and usefulness of tazobactam/piperacillin (TAZ/PIPC), in bacterial pneumonia and lung abscess were determined with PIPC as the control in a multi-institutional comparative study a penicillin antibiotic for injection prepared by combining a newly developed beta-lactamase inhibitor, tazobactam (TAZ), with a broad spectrum penicillin antibiotic, piperacillin (PIPC), at a ratio of 1:4. TAZ/PIPC was intravenously injected at a dose of 2.5 g (titer) twice a day, and PIPC at a dose of 2.0 g (titer) twice a day as a rule for 14 days. The following results were obtained: 1. The efficacy rates for bacterial pneumonia and lung abscess were 94% (80/85) in TAZ/PIPC group and 89% (70/79) in PIPC group, showing no significant difference between the two groups. 2. In a comparison of degrees of improvement in clinical symptoms, signs and laboratory findings, there were no significant differences between the two groups except for results on thoracic rales after three days of administration. 3. As for bacteriological effects, the elimination rates of causative organisms were 98% (40/41) in the TAZ/PIPC group and 80% (28/35) in the PIPC group. Thus, the TAZ/PIPC group was significantly superior to the PIPC group. The TAZ/PIPC group showed significantly better eradication of bacteria as well. Bacteria considered to be pyogenic were detected in 80 patients (43 administered TAZ/PIPC and 37 administered PIPC), but beta-lactamase production was confirmed in only 11 patients of each group. There were no significant differences in bacteriological effects among these patients. Minimum inhibitory concentrations of TAZ/PIPC against beta-lactamase producing organisms were distinctly superior to those of PIPC. 4. Side effects occurred in 10% (10/96) of the TAZ/PIPC group and 7% (7/95) of the PIPC group. Abnormal clinical laboratory test values were observed in 22% (20/92) of the TAZ/PIPC group and 18% (17/93) of the PIPC group. Thus, there were no significant differences between the two administration groups. 5. The usefulness rate in the TAZ/PIPC group was 87% (75/86) and it was 85% (67/79) in the PIPC group, showing no significant difference between them. The results suggest that TAZ/PIPC administered at a dose of 2.5 g (titer) twice a day is more useful than PIPC administered at a dose of 2.0 g (titer) twice a day in the treatment of bacterial pneumonia.

Myosin-actin interaction plays an important role in human immunodeficiency virus type 1 release from host cells

We examined the potential role of myosin and actin in the release of human immunodeficiency virus type 1 (HIV-1) from infected cells. Wortmannin (100 nM to 5 microM), an effective inhibitor of myosin light chain kinase, blocked the release of HIV-1 from infected T-lymphoblastoid and monocytoid cells in a concentration-dependent manner. Cytochalasin D, a reagent that disrupts the equilibrium between monomeric and polymeric actin, also partially inhibited the release of HIV-1 from the infected cells. At the budding stage, myosin and HIV-1 protein were detected in the same areas on the plasma membrane by using dual-label immunofluorescence microscopy and immunoelectron microscopy. In the presence of 5 microM wortmannin, viral components were observed on the plasma membrane by using immunofluorescence microscopy and electron microscopy, implying that wortmannin did not disturb the transport of viral proteins to the plasma membrane but rather inhibited budding.

Induction of human autologous cytotoxic T lymphocytes on formalin-fixed and paraffin-embedded tumour sections

Human autologous tumour-specific cytotoxic T lymphocytes (CTL) were generated from peripheral blood on small formalin-fixed paraffin-embedded sections of a gastric cancer. The CTL killed live target cells at an effector/target ratio of 1 within 24 hours and showed the same target specificity as those induced on live cancer cells. The killing activity of the CTL lasted for more than four months in culture and was inhibited by antibodies against CD8 and MHC-class I. These results suggest that adoptive immunotherapy of tumours will be possible with CTL induced on a stable source of tumour antigen.

Regulation of human retroviral latency by the NF-kappa B/I kappa B family: inhibition of human immunodeficiency virus replication by I kappa B through a Rev-dependent mechanism

The cellular transcription factor NF-kappa B stimulates human immunodeficiency virus type 1 (HIV-1) transcriptional initiation, but its role in the retroviral life cycle has not been fully defined. In this report, we show that I kappa B alpha acts as a cellular inhibitor of human retroviral replication through a discrete mechanism, independent of its effect on HIV transcription. I kappa B alpha inhibited HIV replication and gp160 expression by negatively regulating Rev function, most likely acting through a cellular factor involved in Rev transactivation. A similar effect was observed with human T leukemia virus I, in which I kappa B alpha inhibited Rex function. In contrast, no effect was observed on the replication of a DNA virus, adenovirus type 5. The NF-kappa B/I kappa B regulatory pathway therefore modulates human retroviral replication by regulating a program of cellular gene expression required for several steps in the viral life cycle, including not only viral transcription but also RNA export. This interaction between cellular and viral gene products suggests that NF-kappa B plays a broader role in the regulation of human retroviral replication, providing a previously unrecognized link between two important regulators of HIV gene expression and common NF-kappa B-dependent programs of gene expression used by human retroviruses.

Seroprevalence of hepatitis C virus infection and its genotype in Lanzhou, western China

The seroprevalence of hepatitis C virus (HCV) infection in Lanzhou, Western China was studied. HCV genotypes in 20 patients with HCV infection was determined by genotype-specific primer for polymerase chain reaction (PCR) based on HCV core region and compared with the genotype assigned by sequence comparison and molecular evolutionary analysis based on the same region. Antibody to HCV (anti-HCV) was present in 2.5% of volunteer blood donors and in 35.0% of paid blood donors (P < 0.01). HCV infection is uncommon in patients with liver disease who attended liver clinics in this locality; 4.0% with acute hepatitis and 4.0% with chronic hepatitis, 10.0% with liver cirrhosis, and none with hepatocellular carcinoma were seropositive for anti-HCV. Genotype 1b and 2a were both found to be prevalent. Together, they accounted for 19 of 20 (95%) patients with HCV infection. Sequencing of the HCV core region from two patients showed that the assignment of HCV genotype by genotype-specific primers for PCR matched well with the genotyping results based on sequence comparison and molecular evolutionary analysis. These data showed that HCV is present in Western China, HCV infection is more common in paid blood donors, and HCV genotypes 1b and 2a are both prevalent in Western China.

[Clinical investigation of severe pulmonary tuberculosis and miliary tuberculosis]

Although the incidence of pulmonary tuberculosis had been rapidly decreased in Japan, it is pointed out that the rate of decrease in annual incidence became smaller in recent years. This slowing down of the rate of decrease is considered to be resulted from an increase in number of individuals who are more susceptible to tuberculous infection; such as the elderly, young people who are not exposed to TB bacilli previously and therefore not immunized, patients with malignant disease or with organ transplantation and HIV-infected persons. Pulmonary tuberculosis still remained as a pulmonary infectious disease of highly ranked importance. Especially, miliary tuberculosis is life-threatening and occasionally fatal unless early intensive antituberculosis chemotherapy was started on the basis of a rapid and definite diagnosis. We made a retrospective survey to clarify the characteristic clinical features of miliary tuberculosis. For this purpose, we compared the characteristics and clinical features of 10 patients with miliary tuberculosis and those of 18 patients with severe pulmonary tuberculosis, not due to hematogenous dissemination. The mean ages of miliary tuberculosis group and that of severe pulmonary tuberculosis group were 62.6 and 63.8 years old, respectively, with no significant difference. Nine out of ten patients with miliary tuberculosis had fever as one of initial symptoms, whereas, all the patients with severe pulmonary tuberculosis had cough and sputa but they seldom developed fever (high fever) at the initial stage of their diseases. Duration from onset of symptom to the admission was 1.2 months on average in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Application of six hepatitis C virus genotyping systems to sera from chronic hepatitis C patients in the United States

Serum samples from 139 US patients with chronic hepatitis C virus (HCV) infection were studied using six different genotyping systems, including both molecular and serologic methods, to determine the applicability of these approaches and the prevalence of various HCV subtypes. The concordance of genotyping results based on the various systems (except for core polymerase chain reaction genotyping) was good (93.5%). Subtypes 1a and 1b were prevalent (37.4%). Subtypes 2a (2.2%), 2b (8.6%), and 3a (5.8%) were less common. HCV genotypes could not be determined in 3.4%-16.5% of samples depending on the method used. HCV type 2 was associated with greater histologic activity but lower serum HCV RNA levels (P < .05), whereas type 3 was associated with lower serum alanine aminotransferase levels (P < .05). These data demonstrate a high concordance between HCV genotyping systems and provide a foundation for comparison of genotyping data between studies using different systems. HCV types 1a and 1b are both prevalent in the United States.

Proliferation of chick primordial germ cells cultured on stroma cells from the germinal ridge

Fluorescent reagent-labelled PGCs isolated from the blood of 2-day-old chick embryos were cultured on stroma cells derived from 5-day-old germinal ridge in Medium 199 supplemented with 10% FBS, human IGF-1, bovine FGF-b, and murine LIF. In 7 experiments, the number of MCs increased by an average of 4.8 fold in 4 days. Intrinsic PGCs in the 5-day embryonic germinal ridge were observed loosely attached to the stroma cells, and they also increased 3.8 fold during culture for 4 days. These results indicate the possibility of applying this culture method to the production of transgenic chickens.

C-type natriuretic peptide inhibits intimal thickening after vascular injury

Recently we have found that C-type natriuretic peptide (CNP) inhibits proliferation of cultured rat vascular smooth muscle cells through an elevation of cGMP. We have now tested whether administration of CNP inhibits the development of intimal lesions induced by air-drying injury in rat common carotid arteries in vivo. CNP treatment (1 microgram/kg per min, iv infusion) for either 14 or 5 days resulted in 70% or 60% reduction, respectively, of intimal cross-section area 14 days after injury as compared with control rats. We also found that CNP potently stimulated cGMP production in injured carotid arteries with intimal thickening, but not in intact ones. These results indicate that GC-B, CNP specific receptor/guanylyl cyclase, is expressed at the sites of vascular injury, and that CNP might be efficacious in the prevention of restenosis caused by intimal thickening following coronary angioplasty.

Measurement of yeast intracellular pH by image processing and the change it undergoes during growth phase

The intracellular pH of the yeast Saccharomyces cerevisiae was determined by a fluorescence microscopic image processing technique. Image processing was carried out using a modification of the ratio imaging method for measurement of yeast intracellular pH. Care was necessary when taking fluorescence images in order to obtain accurate measurement of yeast intracellular pH. Until now it has been difficult to measure the intracellular pH of cells in actual cultivation conditions. This method enabled us not only to measure the intracellular pH of dilute cell suspensions, but also to obtain two-dimensional information. In the case of resting cells, the intracellular pH was dependent upon the extracellular pH, and this value was constant when the extracellular pH was constant. On the other hand, in the case of actively growing cells, intracellular pH was found to change, even if the extracellular pH was constant: the values observed were intracellular pH 5.7 during lag phase, intracellular pH 6.8 during exponential phase and intracellular pH 5.5 during stationary phase. These results for intracellular pH indicate that the yeast proton pump was activated during growth from the point of view of pH in vivo.