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Fluctuations of the neutral point voltage in NPC power converters cause problems such as excessively high voltage applied to their power devices. This paper presents a novel method of controlling the neutral point voltage by adjusting the dead-time that is required to prevent a DC-link short circuit. To analyze the dynamic effects of dead-time, a state-space averaged model for an NPC power converter is derived. This control method is applicable to single-phase NPC power converters, independent of the polarity of power flow, and free from the undesired variation of switching frequency of PWM. Experimental results have revealed satisfactory control performance.

Dyskeratosis congenita (DKC) is a rare inherited disease characterized by reticulated pigmentation of the skin, nail dystrophy and oral leukoplakia. More than 90% of DKC cases are inherited as an X-linked recessive trait. Half the patients develop progressive pancytopenia by the age of 11 yr, and this is the leading cause of death. We experienced a 11-year-old boy with the above symptomatic triad of DKC, complicated by progressive pancytopenia as well as cerebellar ataxia. Genetic analysis of mRNA from his cultured peripheral lymphocytes revealed a missense mutation resulting in substitution of 1,150 C with T in the DKC1 gene. This is identical to the mutation reported by Knight et al. to be prevalent in X-linked cases of DKC (11 out of 21 patients). Existence of the identical mutation in Japan suggests that this mutation has been selected on the basis of not only the DNA structural sequence of dyskerin, but also its biological function. We report the detailed clinical course of this Japanese DKC patient with a mutation in the DKC1 gene, and describe the results of genetic analysis.

Duocarmycins have been reported to derive their potent antitumor activity through a sequence-selective minor groove alkylation of N3 adenine in double-stranded DNA. We have used gel mobility shift assays to detect proteins that bind to DNA treated in vitro with duocarmycin SA and identified a protein, named duocarmycin-DNA adduct recognizing protein (DARP), which binds with increased affinity to duocarmycin-damaged DNA. Examination with partially purified DARP revealed that the protein recognized not only the DNA adduct of structurally related drug, CC-1065, but unexpectedly, the protein also recognized the DNA adduct of another chemotype of minor groove binder, anthramycin. These results demonstrate that DARP recognizes the structural alteration of DNA induced by these potent DNA-alkylating drugs, suggesting the possibility that the protein might modulate the antitumor activity of these drugs.

A 44-year-old woman had been diagnosed with progressive systemic sclerosis (PSS) at the age of 39 years old and mild pancytopenia was noted at that time. At the age of 41 years symptoms of dry mouth appeared. In April 1997, anemia was in progress (Hb 5.8 g/dl) and severe esophageal varices were found by gastrointestinal fiber scope, and massive splenomegaly by abdominal CT. Serological examination was negative for hepatitis virus and for anti-mitochondrial antibody. In addition, Indocyanine Green test was normal and typical findings of liver cirrhosis were not demonstrated by CT scan. Also, the bone marrow result was normal. Therefore hypersplenism with idiopathic portal hypertension (IPH) was suggested and the patient was referred for splenectomy with the aim of improving the pancytopenia. The weight of the spleen was 2100 g and the pressure of the portal vein was measured at 390 mm H2O. The diagnosis of IPH was determined because pathologically there were no findings for liver cirrhosis. After splenectomy, pancytopenia was remarkably improved (Hb 9.6 g/dl). Consequently, this case was diagnosed as IPH complicated with PSS and Sjögren syndrome.

UCN-01 (7-hydroxyl-staurosporine) was originally isolated as a Ca2+- and phospholipid-dependent protein kinase C selective inhibitor and now is being developed as an anticancer agent. Results from our and other laboratories have suggested that UCN-01 induces preferential G1-phase accumulation in several human tumor cell lines tested. To elucidate this mechanism, we examined the effects of UCN-01 on several cell cycle-regulatory proteins critical for G1-S-phase transition in p53-mutated human epidermoid carcinoma A431 cells. After 24 h exposure at around 50% growth-inhibitory concentrations (IC50s), 260 and 520 nM, UCN-01 induced the accumulation of pRb (the dephosphorylated retinoblastoma protein form). The protein expression of cyclin A but not cyclin E was markedly reduced and that of cyclin D1 was partially reduced under the same condition. UCN-01 also showed the concentration-dependent inhibitions of the activity of cyclin-dependent kinase 2 (CDK2) using histone H1 and pRb as substrates in vitro (IC50, 530 and 640 nM, respectively). In addition, CDK2 activities of the cells pretreated with UCN-01 for 24 h at 260 and 520 nM were markedly inhibited, giving IC50s of far less than 260 nM. When the same cell lysates were analyzed by Western blotting for CDK2, the lower band (e.g., active and phosphorylated CDK2) was remarkably reduced, in accordance with the reduced activity. Furthermore, UCN-01 induced the expression of the CDK inhibitor p21 protein and its complex formation with CDK2 after 24 h exposure at 260 and 520 nM, whereas the expression level was very low or undetectable in untreated or DNA-damaged cells. The increase of p21 mRNA levels was also induced under the same condition. UCN-01 further increased luciferase activities in A431 cells transiently transfected with p21 promoter-luciferase reporter plasmid after 24 h exposure at 260 and 520 nM. UCN-01 also increased the expression of the CDK inhibitor p27 protein after 24 h exposure at 260 and 520 nM. These results suggest that G1-phase accumulation induced by UCN-01 is associated with dephosphorylation of Rb and CDK2 proteins as well as induction of CDK inhibitors p21 and p27.

The chromosomal DNA of Streptomyces griseus 2247 (a derivative of strain IFO3237) was digested with several restriction endonucleases and analyzed by pulsed-field gel electrophoresis (PFGE). Digestion with AseI and DraI gave 15 and 9 fragments, respectively, the total sizes of which were 7.8 Mb. All the AseI and DraI fragments were aligned on a linear chromosome map by using linking plasmids and cosmids. PFGE analysis of the intact chromosome also showed a linear DNA band of about 8 Mb. Detailed physical maps of both terminal regions were constructed; they revealed the presence of a 24-kb terminal inverted repeat on each end. PFGE analysis with and without proteinase K treatment suggested that each end of the chromosome carries a protein molecule.

We have developed an enzyme-linked immunosorbent assay (ELISA) for the detection of IgG antibodies against Helicobacter pylori (HP) using purified HP urease as an antigen. The urease was purified from ultrasonicated extract of HP by NaCl linear gradient system on DEAE-Sepharose 4B chromatography. Two molecular weight bands, 65kD and 27kD were observed on a SDS-PAGE gel in the purified urease sample. The urease antigen did not crossreact to rabbit antibodies prepared against Campylobacter coli and Campylobacter jejuni. Out of 93 gastric biopsy patients, sixty nine patients (74.2%) were positive in HP culture test. Serum HP antibody titers (AU: arbitrary unit) of HP culture positive and negative patients were 42.9 +/- 47.4 and 16.7 +/- 25.7 (mean +/- SD), respectively (p0.05). The ELISA system have sensitivity of 72.5% and specificity of 70.8%. We believe that the ELISA system is useful for diagnosis and monitoring of HP infection.

Erythropoietin (Epo) exerts its effects by binding specific receptors on the surface of reactive cells. However, the signal transduction system after binding has not been well described. To develop a system to analyze the steps of signal transduction, we transfected the human c-fos-enhancer/promoter linked with the Photinus pyralis luciferase gene (pfosluc2) into a murine erythroleukemia cell line ELM-I-1, in which we previously showed that c-fos mRNA is rapidly induced upon Epo-stimulation. A stable transfectant was obtained. The cells transfected with pfosluc2 were stimulated with Epo and luciferase activity in the cells was measured as light intensity. The light intensity integrated for 2 min (LI2.0) was 3202 +/- 80 unit/1.5 x 10(5) cells before stimulation. This increased up to 5869 +/- 321 unit/1.5 x 10(5) cells by incubating the cells with 5 U/ml Epo for 2 h. After Epo stimulation, light intensity began to increase at 30 min, reached a peak (about 1.8 times the basal level) at 120 min, and then gradually dropped. The effect of Epo was dose-dependent; significant action occurred at as low as 0.5 U/ml, with a maximum at 5 U/ml. A similar response was observed when the cells were stimulated with interleukin-3 (IL-3) although the response was apparently lower than that with Epo. It was also found that IL-3 had an additive action with Epo on c-fos activity in this system. Thus, the above method was proven to be simple, rapid and sensitive enough to use to determine the early phase of signal transduction of Epo.

A 56-year-old male patient on chronic hemodialysis developed liver cirrhosis. He received a total of 20 liters of blood transfusion. Bronze pigmentation of the skin and iron deposition to the liver, spleen, pancreas and thyroid gland, which was demonstrated by computed tomography and magnetic resonance imaging studies, and histological demonstration of iron deposition to the thyroid gland, bone marrow and gastric mucosa established a diagnosis of secondary hemochromatosis. Endocrine work-up revealed the presence of diabetes mellitus with minimum insulin secretory response, primary (or thyroprivic) hypothyroidism, hypoparathyroidism and hypogonadotropic hypogonadism. A wide-spread endocrine involvement as seen in this patient is a rare clinical feature of hemochromatosis secondary to massive blood transfusion in hemodialysis patients. Particularly, primary hypothyroidism due to iron deposition to the thyroid gland was quite a rare feature of hemochromatosis.

To make a reliability design in ceramic application, the probablistic evaluation method of retained strength after the thermal shock is proposed, applying the unified strength evaluation method. The probability of the occurrence of cracks is predicted theoritically and compared with the results of the thermal shock tests using sintered silicon carbide as specimens and liquid sodium as a quenching medium.

金沢大学大学院自然科学研究科情報システム, 金沢大学工学部, A new infinite impulse response (IIR) Nyquist filter with zero intersymbol interference is proposed. The necessary and sufficient conditions for the transfer function are obtained. The proposed IIR Nyquist filter requires only frequency-domain optimization. Multistep optimization, using the iterative Chebyshev approximation, is proposed. This method is able to design a new kind of IIR Nyquist filter with the minimum order. Numerical examples for 30- and 15-percent rolloff rates are illustrated. From these examples, it is confirmed that the IIR approach can reduce the filter order and hardware size, compared with the conventional finite impulse response (FIR) Nyquist filters. Its efficiency becomes marked for high Q Nyquist filters.

A prototype test of an EHV cryoresistive cable cooled by liquid nitrogen was carried out in a 24 m length test line. The structure of the conductor for the cryoresistive cable was investigated experimentally and theoretically to decrease the ac resistance, and the EHV cable core and its terminals were studied simulating the operational conditions. The test results and conclusions obtained are useful for the design of a bulk power transmission cable.

A new method of cross-linked polyethylene cables, vulcanization in inert gas, was researched and developed. In this paper, the principle of the new method of the gas curing process is explained. And then the electrical and physical properties of the cables cured in inert gas are outlined and are compared with those of the cables cured in steam. It is found that the curing method and condition have heavy influence on the micro-structure of the XLPE (cross-linked polyethylene) insulation and electrical strength. In conclusion, we can cure the polyethylene cables in the flow of the high temperature and high pressure inert gas. A.C and impulse breakdown voltage of the cables cured in inert gas (gas-cured cable) were respectively higher about 50∼70% and 20∼ 70% than those of the cables cured in steam (steam-cured cable). By our new method of the gas curing process perhaps insulation thickness will be reduced to 70∼60% of that of the present steam-cured cables. It will be of great advantage to use this method in manufacturing EHV XL-PE insulated power cables.

A 1-Mb DRAM with 128K/spl times/8 bit organization is described. In designing the circuit, half V/SUB cc/ bit line precharge with dummy reverse circuits was adopted for noise reduction. The noise is estimated using a three-dimensional capacitance calculation. In realizing the chip, a 1-/spl mu/m NMOS process with double-level aluminum wiring was used.

INTRODucnoN The bacterial leaf blight disease of rice was first observed in the latter part of the last century in various localities of southern Japan. Severe dam­ age has been caused annually since then. Scant information is available on the occurrence of this disease in other countries. It has been reported in Korea (105), Taiwan (21), the Philippines (15-17, 19, 77), Indonesia (15, 16), Thailand (19), India (5,84,86-88 ), and China (8 ,9 ,107). According to investigations carried out in recent years (59, 66, 119), the disease has become of economic importance in many other countries of Asia, namely Ceylon, Cambodia, and Malaysia. It occasionally causes severe damage to rice yields and is recognized as one of the most important diseases of rice growing areas in Asian countries. No reports of the presence of the disease in America, Australia, Africa, and European countries growing rice have been received. Possibly the disease is nonexistent in these countries or is not of any great importance. Early investiga tions during 190 8 to 1910 indicated that bacterial blight occurred in almost all southwestern prefectures of Japan (73, 79, 104). It gradually spread to northern Japan and in 1962 was observed in Hokkaido. At present, the disease is widespread in all prefectures of Japan, although its severity and damage is limited in the north. The acreage infected by leaf blight disease was 50,000 to 60,000 hectares in 1940, exceeded 100,000 hec­ tares durin g the Second World War, and is now 300,000 to 500,000 hect ares. This corresponds approximately to 10 per cent of the total rice area in Japan.

O-alpha-D-Glucopyranosyl-(1 leads to 4)-O-6-deoxy-6-iodo-alpha-D-glucopyranosyl-(1 leads to 4)-D-glucopyranose (6'-MT), O-alpha-D-glucopyranosyl-(1 leads to 4)-6-deoxy-6-iodo-D-glucopyranose (6-M), and O-6-deoxy-6-iodo-alpha-D-glucopyranosyl-(1 leads to 4)-D-glucopyranose (6'-M) were prepared and their inhibitory action against Taka-amylase A [EC 3.2.1.1, alpha-1, 4-glucan 4-glucanohydrolase, Aspergillus oryzae] was investigated. The inhibitor constants of 6'-MT and 6'-M were 10 mM and 54 mM, respectively, and both inhibitors showed mixed-type inhibition. 6-M scarcely inhibited the enzyme action.

Pancreatic islet cells of rats obtained by the collagenase digestion method were preserved from 7 to 10 days at -80 degrees C in a deep freezer or at -196 degrees C in liquid nitrogen with Dulbecco modified Eagle's medium, supplemented with 10% or 20% DMSO (dimethyl sulfoxide); thawing was performed in a 37 degree C water bath. Cryopreserved islets were morphologically almost intact, and possessed approximately 50% of the insulin secretion activity of the control groups. About 300 pancreatic islets preserved at -196 degrees C with 20% DMSO were transplanted into the portal veins of streptozotocin-induced diabetic rats. Rats recovered from the diabetic state, and the normalized condition was maintained up to 20 weeks, although 4 weeks were needed before blood and urine glucose reached normal levels after transplantation. Intact B cells were found in the transplanted islet cell masses in the liver of the recipients, but B cells of the recipient's pancreases (streptozotocin-treated rats) showed a marked decrease, as well as degenerative changes.

A cleavage map of Bacillus subtilis temperate phage rho 11 was constructed with restriction endonucleases SalI, BamHI and BglII, which cut the genome into 6, 7 and 21 fragments, respectively. The molecular weight of the rho 11 genome was calculated to be 78 x 10(6). Among other endonucleases tested, PvuII, EcoRI and XbaI cleaved the genome into more than 25 fragments, while HaeIII, StuI, BalI and BamNx did not cut the genome at all. The rho 11-coded thymidylate synthetase gene, thyP11, was found to be located in the SalI-D fragment, which was in the central region of the genome.

An alpha-amylase [EC 3.2.1.1] from Streptomyces praecox was purified and its characteristic action, the conversion of maltotriose (G3) to maltose (G2) without appreciable formation of glucose (G1), was investigated. Isoelectric focusing or the glycogen adsorption procedure was employed after chromatography. Isoelectric focusing showed that the enzyme preparation after chromatographic separation comprises three isozymes. The preparation from the glycogen adsorption procedure showed the highest specific activity of any preparation of this enzyme ever obtained. Product analysis with uniformly labeled G3 revealed that at a high concentration (18 mM) of G3, much more G2 is produced than G1 (the product ratio G2/G1 is over 20), while at a lower concentration (10 microM) the reaction mixture was composed of nearly equimolar amounts of glucose and maltose. Based on the product analysis of reducing end-labeled G3 in addition to the above findings, the following conversion mechanism is proposed: Streptomyces alpha-amylase catalyzes transglycosylation to produce maltotetraose (G4) as a transient product which is immediately degraded into two molecules of G2 by a subsequent hydrolytic reaction, i.e., two molecules of G3 are converted into three molecules of maltose without appreciable formation of glucose.

We investigated the effectiveness of the Bladder Assist Device on urinary tract infection of patients with indwelling catheters. The patients, except for those with cord bladder and vesicoureteral reflux, could urinate intermittently under the BLAD system. Irrigation of the bladder using BLAD made urine clear and decreased urinary bacteria. Because of intermittent urination in patients who had been using the BLAD system for two weeks, the urine became somewhat clear and the number of bacteria decreased. Combination of bladder irrigation and intermittent urination using this system may inhibit urinary tract infection of an indwelling catheter. BLAD is considered to be a useful device for patients with continuous indwelling catheters.

HaeIII, BalI, StuI, BamHI, SlaI, and EcoRII did not cut the genome of Bacillus subtilis phage phi 1 at all, whereas ThaI, BglII, EcoRI, SalI, and Bsu1247I cut the genome once or twice. The physical map of the phi 1 genome was constructed with the latter restriction endonucleases.

We report an unusual case of renal sarcoma in a young adult. Histological examination demonstrated many similarities to the histopathological features of clear cell sarcoma of the kidney. Immunohistochemically, none of the intrinsic tumor cells showed positive staining with the antibodies against the intermediate filament proteins, epithelial membrane antigen, S100 protein, neuron-specific enolase, Leu-7 or myoglobin. The clinical course of this tumor was that of high grade malignancy, resulting in death with generalized metastases 13 months after tumor resection.