Observation of Edge Magnetoplasmon Squeezing in a Quantum Hall Conductor

Squeezing of the quadratures of the electromagnetic field has been extensively studied in optics and microwaves. However, previous works focused on the generation of squeezed states in a low impedance (Z_{0}≈50  Ω) environment. We report here on the demonstration of the squeezing of bosonic edge magnetoplasmon modes in a quantum Hall conductor whose characteristic impedance is set by the quantum of resistance (R_{K}≈25  kΩ), offering the possibility of an enhanced coupling to low-dimensional quantum conductors. By applying a combination of dc and ac drives to a quantum point contact, we demonstrate squeezing and observe a noise reduction 18% below the vacuum fluctuations. This level of squeezing can be improved by using more complex conductors, such as ac driven quantum dots or mesoscopic capacitors.

Health-related QOL of elderly patients with pulmonary M. avium complex disease in a university hospital

BACKGROUND

Little is known about the clinical characteristics and health-related quality of life (HQOL) of elderly patients with pulmonary Mycobacterium avium complex (pMAC) disease.

OBJECTIVES

To evaluate HQOL using the 36-Item Short-Form Health Survey and St George's Respiratory Questionnaire (SGRQ) and to investigate the predictors of HQOL changes among elderly patients with pMAC disease.

METHODS

This prospective cohort registry was conducted at Keio University Hospital, Tokyo, Japan, between May 2012 and July 2015 and included 84 patients with pMAC disease aged 75 years who had completed the HQOL questionnaire and 48 patients with pMAC disease who had been followed up and completed the HQOL questionnaire in cross-sectional and longitudinal analyses, respectively.

RESULTS

In cross-sectional analyses, elderly patients with pMAC disease had significantly lower role-physical, general health, vitality, social functioning, role-emotional and role/social component scores than the general Japanese elderly population. Analysis of covariance revealed that patients with cavitary lesions had significantly worse physical functioning and SGRQ scores (P < 0.05). Longitudinal analysis showed that under-treatment, short duration of disease and positive sputum smear at baseline were predictors of worse HQOL at 12 months.

CONCLUSIONS

Elderly patients with pMAC disease have reduced HQOL. Further large studies on HQOL are required to refine the use of this parameter in the treatment of these patients.

Inflammatory Cytokine Gene Expression in Different Types of Granulomatous Lesions during Asymptomatic Stages of Bovine Paratuberculosis

The granulomatous lesions in bovine paratuberculosis have been classified into two types, i.e., the lepromatous type and the tuberculoid type. To clarify the immunopathologic mechanisms at the site of infection, we compared inflammatory cytokine gene expression between the two types of lesions. Samples were obtained from noninfected control cows ( n =5) and naturally infected cows ( n =7) that were diagnosed by enzyme-linked immunosorbent assay (ELISA) and fecal culture test. Although none of the infected cows showed clinical signs, tuberculoid lesions were observed in five cows (tuberculoid group) and lepromatous lesions in two cows (lepromatous group). Among the cytokines examined by reverse transcription-polymerase chain reaction (RT-PCR), Th2-type cytokines interleukin-4 (IL-4) and IL-10, and Th1-type cytokine IL-2 were expressed more significantly in the lepromatous group than in the tuberculoid ( P < 0.01) and noninfected groups ( P < 0.05). No statistical differences were observed in the expression of interferon-gamma, IL-1 beta, TNF-alpha, and GM-CSF among lepromatous, tuberculoid, and noninfected groups. Expression of proinflammatory cytokine IL-12 mRNA, however, did not differ among the three groups; IL-18 was expressed at lower levels in the lepromatous group than in the tuberculoid group and the noninfected group ( P < 0.0001). Moreover, the number of cells in which IL-18 mRNAs were detected by in situ hybridization was markedly decreased in the lepromatous group. These results indicate that the formation of lepromatous-type lesions or tuberculoid-type lesions may be influenced by alterations in Th1/Th2-type cytokine production and that IL-18 may play an important role in a Th1-to-Th2 switch in paratuberculosis.

Fractionalized wave packets from an artificial Tomonaga-Luttinger liquid

The model of interacting fermion systems in one dimension known as a Tomonaga-Luttinger liquid (TLL) provides a simple and exactly solvable theoretical framework that predicts various intriguing physical properties. Evidence of a TLL has been observed as power-law behaviour in electronic transport on various types of one-dimensional conductor. However, these measurements, which rely on d.c. transport involving electron tunneling processes, cannot identify the long-awaited hallmark of charge fractionalization, in which an injection of elementary charge e from a non-interacting lead is divided into the non-trivial effective charge e* and the remainder, e-e* (refs 6, 7, 8). Here, we report time-resolved transport measurements on an artificial TLL composed of coupled integer quantum Hall edge channels, in which we successfully identify single charge fractionalization processes. A wave packet of charge q incident from a non-interacting region breaks up into several fractionalized charge wave packets at the edges of the artificial TLL, from which transport eigenmodes can be evaluated directly. These results are informative for elucidating the nature of TLLs and low-energy excitations in the edge channels.

A novel triple secured technique for pancreatic reconstruction following pancreaticoduodenectomy for a soft pancreas

BACKGROUND/AIMS

Soft pancreases are susceptible to developing pancreatic fistula following pancreaticoduodenectomy. To reduce the incidence of pancreatic fistula after pancreaticoduodenectomy in patients with a soft pancreas, we developed a triple secured technique. In this study, we describe the details of this technique and also report on the postoperative outcomes.

METHODOLOGY

The triple secured technique employed an ultrasonic dissector for pancreatic transection with skeletonizing and ligating of the small pancreatic branch ducts, duct-invagination or duct-to-mucosa anastomosis for main pancreatic duct management, and, finally, four large stitches between the pancreatic stump parenchyma and the jejunal seromuscular layer to prevent minor pancreatic leakage. A total of 28 consecutive patients with a soft pancreas who underwent pancreaticoduodenectomy using our technique were included in this study.

RESULTS

Postopetrative complications occurred in 16 patients. Grade B pancreatic fistula developed in 6 patients. However, no grade C pancreatic fistula occurred in this series. Neither any reoperation nor in-hospital mortality was observed in this series.

CONCLUSIONS

Our triple secured technique after pancreaticoduodenectomy was feasible and safe, with an acceptable rate of grade B pancreatic fistula and no grade C pancreatic fistula for patients with a soft pancreas.

Plasmon transport in graphene investigated by time-resolved electrical measurements

Plasmons, which are collective charge oscillations, could provide a means of confining electromagnetic field to nanoscale structures. Recently, plasmonics using graphene have attracted interest, particularly because of the tunable plasmon dispersion, which will be useful for tunable frequency in cavity applications. However, the carrier density dependence of the dispersion is weak (proportional to n(1/4)) and it is difficult to tune the frequency over orders of magnitude. Here, by exploiting electronic excitation and detection, we carry out time-resolved measurements of a charge pulse travelling in a plasmon mode in graphene corresponding to the gigahertz range. We demonstrate that the plasmon velocity can be changed over two orders of magnitude by applying a magnetic field B and by screening the plasmon electric field with a gate metal; at high B, edge magnetoplasmons, which are plasmons localized at the sample edge, are formed and their velocity depends on B, n and the gate screening effect.

Short communication: Molecular typing of Prototheca zopfii from bovine mastitis in Japan

Prototheca zopfii causes bovine mastitis, resulting in reduced milk production and the secretion of thin watery milk with white flakes. Prototheca zopfii has been biochemically and serologically divided into at least 2 genotypes, P. zopfii genotype 1 and P. zopfii genotype 2. The latter is known to be the main causative agent of bovine protothecal mastitis. Prototheca zopfii was later reclassified into 5 varieties: var. zopfii (genotypes 1 and 2), var. 1 (formerly Prototheca blaschkeae), var. 3 (formerly P. moriformis), and var. portoricensis. In this study, the 18S ribosomal DNA sequences of diverse clinical specimens from different areas in Japan were studied to clarify the pathogenicity of P. zopfii var. zopfii. The phylogenetic tree revealed that all genotype 2 isolates were grouped in a cluster of P. zopfii var. zopfii SAG 2021(T) (type strain genotype 2), and were independent from the cluster of the genotype 1 isolates. Thus, all isolates from bovine mastitis in Japan were identified as P. zopfii genotype 2. Therefore, P. zopfii var. zopfii genotype 2 is associated with bovine mastitis.

Promotion of DNA repair by nuclear IKKβ phosphorylation of ATM in response to genotoxic stimuli

Ataxia-telangiectasia mutated (ATM) is one of the key molecules involved in the cellular response to DNA damage. A portion of activated ATM is exported from the nucleus into the cytoplasm, where it activates the I kappa B kinase/nuclear factor kappa B (IKK/NF-κB) signaling pathway. It has been thought that activated IKKβ, which is a critical kinase for NF-κB activation, generally resides in the cytoplasm and phosphorylates cytoplasmic downstream molecules, such as IκBα. Here, we identified a new role for IKKβ during the response to DNA damage. ATM phosphorylation in response to alkylating agents consisted of two phases: the early phase (up to 3 h) and late phase (after 6 h). A portion of the activated IKKβ generated during the DNA damage response was found to translocate into the nucleus and directly phosphorylate ATM in the late phase. Furthermore, the phosphorylation of ATM by nuclear IKKβ was suggested to promote DNA repair. In parallel, activated IKKβ induced classical NF-κB activation and was involved in anti-apoptosis. Our findings define the function of IKKβ during the response to DNA damage, which promotes cell survival and DNA repair, and maintains cellular homeostasis.

Molecular cloning, in vitro expression and functional characterization of canine ADAMTS13

A disintegrin and metalloproteinase with thrombospondin type 1 motifs, number 13 (ADAMTS13) is a plasma zinc metalloprotease also known as von Willebrand factor (VWF)-cleaving protease. Deficiency of ADAMTS13 activity is known to cause thrombotic thrombocytopenic purpura (TTP) in humans. We isolated the canine ADAMTS13 cDNA, which encodes 1502 amino acids, and expressed the recombinant protein to evaluate VWF-cleaving ability. Although the propeptide domain was longer and the TSP1 repeat domain was shorter than those in other species, the overall structures were similar to human and mouse ADAMTS13. Recombinant canine ADAMTS13 cleaved the 250-kDa VWF monomer into two fragments of 150 kDa and 120 kDa. Furthermore, high molecular weight VWF multimers were abolished based on the activity of ADAMTS13. These results could facilitate research into hemostatic disorders such as TTP in dogs.

Encephalomyelitis of cattle caused by Akabane virus in southern Japan in 2006

Six calves, aged between 55 days and 15 months, were presented between September and November 2006 with neurological signs including limb weakness and circling. Microscopical examination of the brain and spinal cord revealed the presence of non-suppurative encephalitis in all animals. Perivascular cuffing of lymphocytes and macrophages and diffuse gliosis was prominent in the cerebrum and degeneration and/or necrosis of neurons with vacuolation of the neuropil was present in the brainstem. Neuronal necrosis and neuronophagia were noted in the ventral horn of the spinal cord. The distribution of the lesions was closely related to the clinical signs displayed by each calf. Five calves presenting with astasia with low head carriage or torticollis had lesions throughout the central nervous system (CNS). The oldest calf displayed astasia caused by weakness of the "hindlimb" one word and had lesions largely restricted to the caudal spinal cord. Akabane virus (AKAV) antigens were detected immunohistochemically within neurons and axons in lesional tissue. Virus was not isolated from CNS tissue but the AKAV S gene was detected in this tissue from five calves by reverse transcriptase polymerase chain reaction (RT-PCR). It is suggested that AKAV infection is likely to have occurred during the early life period in the calves of this study.

Mutation of the p53 tumour suppressor gene and overexpression of its protein in 62 Japanese non-Hodgkin's lymphomas

To clarify whether p53 mutation could be involved in the pathogenesis of various subtypes of lymphoma, we investigated 62 Japanese cases of non-Hodgkin's lymphomas (NHLs) for p53 gene mutations and their relationship with the expression of p53 protein. Mutations in exons 5-9 of the p53 gene were screened for using the non-isotopic RNase cleavage assay (NIRCA) and confirmed by direct sequencing, followed by immunohistochemical analysis for p53 protein. Missense and/or nonsense mutations of p53 were detected in 3 (10.7%) of 28 diffuse large B-cell lymphomas (DLBLs) and 2 (15.4%) of 13 T-cell NHLs (15.4%). A single missense mutation at codon 157 (Val to Phe) in exon 5 and at codon 273 (Arg to Pro) in exon 8 was found respectively in 2 DLBLs and in one peripheral T-cell lymphoma (unspecified). In these 3 cases harbouring a missense mutation, overexpression of p53 protein was observed in more than 80% of tumour cells. Double transversion mutations comprising of a missense mutation at codon 167 (Gln to His) in exon 5 and a nonsense mutation at codon 183 (Ser to stop codon) in exon 5 were detected in one DLBL that had apparently transformed from follicular lymphoma and in one advanced adult T-cell lymphoma (ATL). In these two cases harbouring p53 nonsense mutation, no cells positive for p53 protein immunostaining were detected, as well as lymphomas without p53 mutation.

Induction of canine pyometra by inoculation of Escherichia coli into the uterus and its relationship to reproductive features

To characterize oestrus-related factors affecting the induction of and recovery from pyometra in bitches, 60 clinically healthy beagle bitches were used for induction of pyometra by inoculation of Escherichia coli into the uterus during oestrous and metoestrous stages. The animals were classified into the following six groups according to inoculation time: Days 1-10, 11-20, 21-30, 31-40, 41-50 and 51-60 after LH surge. The incidence of pyometra during the periods Days 11-20 and 21-30 after LH surge was 90.9% and 78.9% respectively, while that during Days 1-10 and 51-60 after LH surge was less than 20%, and the patterns of the incidence of pyometra and the serum progesterone levels were similar. There was no difference in the incidence of pyometra induced in bitches less than 5 years old compared to bitches over 6 years old. Oestrus in all of the bitches with pyometra induced by E. coli returned with or without PGF 2alpha treatment, unlike in bitches with spontaneous pyometra. The duration of the oestrous cycle in the non-treated and PGF 2alpha-treated groups was 231.4+/-55.2 days and 162.1+/-40.6 days (P < 0.001), respectively, and there was no difference in the rate of return of oestrus between the two groups. The conception rate in all of the bitches in which oestrus had returned was 81.8%. The above findings indicate that the period during which severe pyometra could be induced was limited to the early stage in metoestrus.

A PLCdelta1-binding protein, p122RhoGAP, is localized in focal adhesions

We have investigated the cellular distribution of p122RhoGAP, a GTPase-activating protein of Rho small GTPase and an activator of phospholipase C-delta(1). Immunofluorescence studies demonstrated that endogenous p122 is localized at the tips of actin stress fibres and co-localizes with vinculin in normal rat kidney cells. In immunoprecipitation studies, p122 co-precipitated with vinculin, indicating that p122 is localized at the sites of focal adhesion. We have also shown that the N-terminal half of p122 is responsible for this localization. It is conceivable, therefore, that p122 is involved in the reorganization of the actin cytoskeleton and focal adhesions that regulate cell-substratum adhesion and cell migration.

The resurgence of Shamonda virus, an African Simbu group virus of the genus Orthobunyavirus, in Japan

Six virus isolations were made from Culicoides biting midges and blood samples of sentinel cattle in Kagoshima and Miyazaki Prefectures, the southern part of Japan, in 2002. Serological and genetical tests identified these viruses as isolates of Shamonda virus (SHAV), which belongs to the Simbu group of the genus Orthobunyavirus of the family Bunyaviridae. Initially, SHAV was isolated from cattle and Culicoides biting midges in Nigeria in the 1960s, and its presence has not been reported until this study. The present results indicate a wider distribution of SHAV than previously assumed.

Cold-induced ascites in broiler chickens and its improvement by temperature-controlled rearing

Pulmonary hypertension syndrome (PHS), also known as ascites, in broiler chickens prevailed in the local area of Ibaraki prefecture, Japan, and was investigated epidemiologically, serologically, and pathologically. PHS developed in chickens older than 35 days of age when rapid increase of body weight started. Approximately 90% of affected birds were males, in which weight increase was greater than in females. Serologic test revealed that PHS broilers had an increase of hematocrit value. Pathologic studies indicated that the heart of affected birds had an obese-induced pressure and cold exposure triggered congestion in the right ventricle/cava and an increase in peritoneal fluid. These changes were consistent with the previous reports of PHS, so we designed the experiment of effects on cold-induced PHS birds in a temperature-controlled house. After the 10 PHS birds at 55 days were reared for 14 days in a temperature-controlled house at 20 +/- 5 C, ascites disappeared in eight birds and hematocrit values decreased to normal range in nine birds. Our finding indicated that temperature-controlled environment may be one solution to reduce mortality in PHS birds.

Case report. First isolation of Trichosporon domesticum from a cat

The present study deals with the first isolation of Trichosporon domesticum from the urine of a cat with chronic cystitis. A 5-year-old domestic short hair cat weighing 5.6 kg was referred to an animal hospital with the chief complaint of haematuria having persisted for 3 weeks. The isolate was identified as T. domesticum, confirming the result of mycological examination by molecular analysis.

Cycloprodigiosin hydrocloride suppresses tumor necrosis factor (TNF) alpha-induced transcriptional activation by NF-kappaB

Cycloprodigiosin hydrochloride (cPrG.HCl) obtained from a marine bacterium Pseudoalteromonas denitrificans induces apoptotic cell death in various cancerous cell lines. cPrG.HCl alone caused a little cytotoxicity in HeLa cells, but it enhanced the apoptotic process progressively when co-administered with tumor necrosis factor (TNF)alpha. Here we studied the effect of cPrG.HCl on TNFalpha-induced activation of the transcription factor nuclear factor kappaB (NF-kappaB). Luciferase gene reporter assays revealed that cPrG.HCl potently suppressed the TNFalpha- and the phorbol myristate acetate-induced activation of NF-kappaB. The suppression occurred in the presence of imidazole, indicating that it was not related to the intracellular acidification resulting from the intrinsic H(+)/Cl(-) symporter activity of cPrG.HCl. cPrG.HCl inhibited neither the TNFalpha-induced phosphorylation and degradation of inhibitor of nuclear factor-kappaB, nor the subsequent nuclear translocation and DNA binding of NF-kappaB. cPrG.HCl also suppressed NF-kappaB-enhanced gene expression induced by Rac1, Cdc42, MEKK1, inhibitor of nuclear factor-kappaalpha (IKKalpha), IKKbeta, and a subunit of NF-kappaB, p65. These results indicate that cPrG.HCl suppresses NF-kappaB-dependent gene expression through the inhibition of transcriptional activation.

Molecular identification of Candida parapsilosis from crop mucosa in a cockatiel

A 2-month-old cockatiel was evaluated for diarrhea, dyspnea, and death. Histologic examination of lesions in the crop mucosa revealed hyperkeratosis and the presence of blastoconidia and hyphae. Positive immunohistochemical staining of the organisms was achieved with an antibody directed against Candida spp. Polymerase chain reaction amplification of DNA from crop lesion material with internal transcribed spacer 2 (ITS2) primers yielded fragments of approximately 300 bp, which demonstrated 95% DNA homology with the corresponding sequence from a strain of Candida parapsilosis deposited in the GenBank data base. The Candida species in the lesion of the crop mucosa was therefore identified by DNA sequence analysis as C. parapsilosis.

Analysis of c-myc DNA amplification in non-small cell lung carcinoma in comparison with small cell lung carcinoma using polymerase chain reaction

Previous studies of c-mvc DNA amplification in lung cancer have focused primarily on analysis of small cell carcinoma or its tumor cell lines. There are few data about c-myc DNA amplification in histological types of lung cancer other than small cell carcinoma. Therefore the present study was conducted to investigate c-myc oncogene amplification in non-small cell lung carcinoma. We studied 46 lung tumor specimens for c-myc DNA amplification (15 adenocarcinomas, 15 squamous cell carcinomas, 6 large cell carcinomas, and 10 small cell carcinomas). Polymerase chain reaction, digoxigenin DNA labeling, and electrophoresis were utilized to investigate the c-myc copy number in the lung tumor specimens. The c-myc copy number of non-small cell carcinoma ranged from 1.5 to more than 20.0 in adenocarcinoma and squamous cell carcinoma, and from 6.0 to 12.0 in large cell carcinoma. That of small cell carcinoma ranged from 1.8 to 12.0. The c-myc copy number of non-small cell carcinoma was significantly higher than that of small cell carcinoma (Wilcoxon rank sum test, Z=2.06 P=0.040). However, the differences in c-myc copy number among these four histological types were not statistically significant. Amplification of c-myc (more than 4 copies) was observed not only in small cell carcinoma but also in nonsmall cell carcinoma at similarly high frequency (12/15 in adenocarcinoma and squamous cell carcinoma, 6/6 in large cell carcinoma, and 9/10 in small cell carcinoma).

Rinderpest virus (RPV) ISCOM vaccine induces protection in cattle against virulent RPV challenge

Rinderpest virus (RPV), a member of genus Morbillivirus in the family Paramyxoviridae, causes an acute and often fatal disease in cattle and other large ruminants. A subunit rinderpest vaccine consisting of an immune-stimulating complex (ISCOM) incorporating the RPV haemaggulutinin (H) protein, was examined for its ability to induce protective immunity in cattle, the natural host of RPV. All of four cattle vaccinated with the ISCOM vaccine survived challenge with virulent virus. Three were solidly protected, showing no clinical signs of infection, while the fourth animal developed only mild and transient symptoms. Virus neutralizing antibodies were produced at a significant level in all vaccinated cattle. These results indicate that this ISCOM vaccine is effective in producing protective immunity in cattle and should be a suitable means of delivering glycoprotein antigens from other morbilliviruses.

Influences of alkaline ionized water on milk electrolyte concentrations in maternal rats

We previously reported that body weight on day 14 after birth in male offspring of rats given alkaline ionized water (AKW) was significantly heavier than that in offspring of rats given tap water (TPW), but no significant difference was noted in milk yield and in suckled milk volume between the two groups. Additionally, the offspring in the AKW group and TPW group were given AKW and TPW, respectively, at weaning, and unexpectedly, the necrotic foci in the cardiac muscle were observed at the 15-week-old age in the AKW group, but not in the TPW group. The present study was designed to clarify the factors which are involved in that unusual increase of body weight and occurrence of cardiac necrosis. Eight dams in each group were given AKW or TPW (control) from day 0 of gestation to day 14 of lactation. The milk samples were collected on day 14 of lactation and analyzed for concentrations of calcium (Ca), sodium (Na), potassium (K), magnesium (Mg) and chloride (Cl). The AKW and TPW were also analyzed. Ca, Na and K levels in milk were significantly higher in the AKW group compared to the TPW group. No significant difference was noted in the Mg and Cl levels between the two groups. These data suggested that the Ca cation of AKW enriched the Ca concentration of the milk and accelerated the postnatal growth of the offspring of rats given AKW.

Identification of T-helper cell epitopes in the hypervariable region of the nucleocapsid (N) protein of rinderpest virus (RPV) in cattle

The proliferative responses to synthetic peptides by lymphocytes derived from rinderpest virus (RPV)-infected cattle, the natural host for RPV, were assayed by determining [3H]thymidine incorporation into the DNA. In eight out of twelve cattle tested, significant responses were detected to peptides representing amino acids 452-501 in the C-terminal hypervariable region of the virus nucleocapsid (N) protein. It appears that helper T-cell epitope(s) for cattle which can be broadly recognized within an MHC diverse population, exists in this region of the protein.

N-acetylcysteine suppresses TNF-induced NF-kappaB activation through inhibition of IkappaB kinases

Here, we used a reductant, N-acetyl-L-cysteine (NAC), to investigate the redox-sensitive step(s) in the signalling pathway from the tumor necrosis factor (TNF) receptor to nuclear factor kappaB (NF-kappaB). We found that NAC suppressed NF-kappaB activation triggered by TNF or by overexpression of either the TNF receptor-associated death domain protein, TNF receptor-associated factor 2, NF-kappaB-inducing kinase (NIK), or IkappaB kinases (IKKalpha and IKKbeta). NAC also suppressed the TNF-induced activation of IKKalpha and IKKbeta, phosphorylation and degradation of IkappaB, and nuclear translocation of NF-kappaB. Furthermore, NAC suppressed the activation of IKKalpha and IKKbeta triggered by the overexpression of NIK. These results indicate that IKKalpha and IKKbeta are subject to redox regulation in the cells, and that NAC inhibits NF-kappaB activation through the suppression of these kinases.

Epidermal growth factor receptor is modulated by redox through multiple mechanisms. Effects of reductants and H2O2

The cellular redox state has been shown to play an essential role in cellular signaling systems. Here we investigate the effects of reductants and H2O2 on the signaling of epidermal growth factor (EGF) in cells. H2O2 induced the phosphorylation of the EGF receptor and the formation of a receptor complex comprising Shc, Grb2, Sos, and the EGF receptor. Dimerization or oligomerization of the EGF receptor was not induced by H2O2. Protein tyrosine phosphatase (PTP) assay showed that H2O2 suppressed dephosphorylation of the EGF receptor in cell lysates, suggesting that inactivation of PTP was involved in H2O2-induced activation of the EGF receptor. In contrast, the reductants N-acetyl-L-cysteine [Cys(Ac)] and dithiothreitol markedly suppressed EGF-induced dimerization and activation of the EGF receptor in cells. In accordance with suppression of the EGF receptor, Cys(Ac) suppressed EGF-induced activation of Ras, phosphatidylinositol 3-kinase and mitogen-activated protein kinase. Dithiothreitol completely inhibited EGF binding and kinase activation of the EGF receptor both in vitro and in vivo. In contrast, Cys(Ac) suppressed high-affinity EGF-binding sites on the cells, but had no effect on low-affinity binding sites. Furthermore, Cys(Ac) did not suppress EGF-induced kinase activation or dimerization of the EGF receptor in vitro, indicating that it suppressed the EGF receptor through a redox-sensitive cellular process or processes. Thus, the EGF receptor is regulated by redox through multiple steps including dephosphorylation by PTP, ligand binding, and a Cys(Ac)-sensitive cellular process or processes.

Phospholipase C-delta1 contains a functional nuclear export signal sequence

We have previously observed, using a green fluorescent protein (GFP) fusion system, that PLC-delta1 is localized mainly at the plasma membrane and in the cytosol, whereas little is present in the nucleus in Madin-Darby canine kidney cells (Fujii, M., Ohtsubo, M., Ogawa, T., Kamata, H., Hirata, H., and Yagisawa, H. (1999) Biochem. Biophys. Res. Commun. 254, 284-291). Herein, we demonstrate that PLC-delta1 has a functional nuclear export signal (NES) sequence in amino acid residues 164-177 of the EF-hand domain. The fluorescence of NES-disrupted GFP/PLC-delta1 expressed in Madin-Darby canine kidney cells was present not only at the plasma membrane and in the cytosol but also in the nucleus. Moreover, treatment with leptomycin B, a specific inhibitor of NES-dependent nuclear export, resulted in the accumulation of GFP/PLC-delta1 in the nucleus. A site-directed mutant containing a pleckstrin homology domain, which does not bind inositol 1,4,5-trisphosphate and cannot hydrolyze phosphatidylinositol 4,5-bisphosphate in vitro, accumulated in the nucleus to a much greater extent than wild-type GFP/PLC-delta1 after treatment with leptomycin B. These results suggest that PLC-delta1 is shuttled between the cytoplasm and the nucleus; its nuclear export is dependent on the leucine-rich NES sequence and its active nuclear import is regulated by an unidentified signal(s).

Overexpression of the alanine carrier protein gene from thermophilic bacterium PS3 in Escherichia coli

The alanine transporter (alanine carrier protein, ACP) gene of thermophilic bacterium PS3 was previously cloned and expressed in a functionally active form in Escherichia coli cells. To achieve controlled overproduction of the ACP protein, we designed a plasmid encoding a fusion protein comprising ACP joined to the carboxyl terminus of the maltose binding protein (MBP-ACP). Upon transduction of the plasmid into E. coli RM1 cells defective in alanine/glycine transport, the transport activity was expressed even before induction with 1-thio-beta-D-galacto-pyranoside (IPTG), and increased slightly on induction with IPTG at low concentrations. However, overexpression of the MBP-ACP gene, induced by higher concentrations of IPTG, resulted in death of the host cells. Hence we screened other host cells and found that the MBP-ACP fusion protein was produced in a large quantity in E. coli TB1 cells 3 h after IPTG induction. The MBP-ACP fusion protein was accumulated in cytoplasmic membranes in an amount reaching more than 20% of the total membrane protein. The affinity-purified MBP-ACP exhibited very low transport activity when reconstituted into proteoliposomes.

Real-time visualization of PH domain-dependent translocation of phospholipase C-delta1 in renal epithelial cells (MDCK): response to hypo-osmotic stress

Green fluorescent protein (GFP)-tagged phospholipase C (PLC)-delta1 and its mutants were expressed in Madin-Darby canine kidney (MDCK) cells. GFP-PLC-delta1 or the GFP-tagged pleckstrin homology (PH) domain of PLC-delta1 itself was found to be predominantly localized at the plasma membrane. The DeltaPH mutant or a site-directed mutant containing a PH domain which does not bind inositol 1,4, 5-trisphosphate and cannot hydrolyze phosphatidylinositol 4, 5-bisphosphate in vitro was seen only in the cytosol. In living MDCK cells hypo-osmotic stress caused a rapid dissociation of GFP-PLC-delta1 from the plasma membrane, which coincided with phosphoinositide breakdown. A PLC inhibitor, U73122, blocked this translocation, but depletion of extracellular Ca2+ had no effect. The translocation was reversed by replacement with an iso-osmotic buffer. Our results demonstrate that the PH domain plays a critical role in the membrane targeting of PLC-delta1 and that the intracellular distribution of the enzyme is regulated by osmotic stress-driven phosphoinositide turnover.

Redox regulation of cellular signalling

Extracellular stimuli elicit a variety of responses, such as cell proliferation and differentiation, through the cellular signalling system. Binding of growth factors to the respective receptor leads to the activation of receptor tyrosine kinases, which in turn stimulate downstream signalling systems such as mitogen-activated protein (MAP) kinases, phospholipase Cgamma (PLCgamma) and phosphatidylinositol 3-kinase. These biochemical reactions finally reach the nucleus, resulting in gene expression mediated by the activation of several transcription factors. Recent studies have revealed that cellular signalling pathways are regulated by the intracellular redox state. Generation of reactive oxygen species (ROS), such as H2O2, leads to the activation of protein tyrosine kinases followed by the stimulation of downstream signalling systems including MAP kinase and PLCgamma. The activation of PLCgamma by oxidative radical stress elevates the cellular Ca2+ levels by flux from the intracellular Ca2+ pool and from the extracellular space. Such reactions in the upstream signalling cascade, in concert, result in the activation of several transcription factors. On the other hand, reductants generally suppress the upstream signalling cascade resulting in the suppression of transcription factors. However, it is well known that cysteine residues in a reduced state are essential for the activity of many transcription factors. In fact, in vitro, oxidation of NFkappaB results in its activation, whereas reductants promote its activity. Thus, cellular signalling pathways are generally subjected to dual redox regulation in which redox has opposite effects on upstream signalling systems and downstream transcription factors. Not only are the cellular signalling pathways subjected to redox regulation, but also the signalling systems regulate the cellular redox state. When cells are activated by extracellular stimuli, the cells produce ROS, which in turn stimulate other cellular signalling pathways, indicating that ROS act as second messengers. It is thus evident that there is cross talk between the cellular signalling system and the cellular redox state. Cell death and life also are subjected to such dual redox regulation and cross talk. Death signals induce apoptosis through the activation of caspases in the cells. Oxidative radical stress induces the activation of caspases, whereas the oxidation of caspases results in their inactivation. Furthermore, some cell-death signals induce the production of ROS in the cells, and the ROS produced in turn stimulate the cell-death machinery. All this evidence shows that the cell's fate is determined by cross talk between the cellular signalling pathways and the cellular redox state through a complicated regulation mechanism.

Biological roles of angiotensin II via its type 2 receptor during rat follicle atresia

Type 1 angiotensin II (ANG II) receptors play crucial roles in the regulation of blood pressure and fluid osmolarity, whereas the physiological roles of type 2 ANG II receptors (AT2) remain unclear. Because AT2 is expressed in atretic follicles where granulosa cells undergo apoptosis, we examined the space and time relationship between AT2 expression and follicle atresia in vivo and the effect of AT2 on follicle-stimulating hormone (FSH) actions in vitro. Binding studies, autoradiography, and RT-PCR of AT2 revealed that the AT2 content in granulosa cells was time dependently increased at both protein and mRNA levels in equine chorionic gonadotropin-treated immature female rats. This increase paralleled the progression of atresia. ANG II suppressed FSH-caused prevention of DNA fragmentation, increases in luteinizing hormone receptor content, and estrogen production through AT2 in cultured granulosa cells. Moreover, FSH-induced stimulation of extracellular signal-regulated kinase activity, critical for cell survival, was inhibited by AT2 stimulation. These results suggest that AT2 mediates the progression of follicle atresia through granulosa cell apoptosis by inhibiting FSH actions.

Histopathological influence of alkaline ionized water on myocardial muscle of mother rats

We have reported that a marked necrosis and subsequent fibrosis of myocardium occurred among male rats 15 weeks old given alkaline ionized water (AKW) during gestation and suckling periods, and after weaning. In this study, it was examined whether similar lesions would occur in mother rats which were given AKW from day zero of gestation to day 20 of lactation. The myocardial lesion in the mother rats given AKW showed cell infiltration, vacuolation and fibrosis in the papillary muscle of the left ventricle, as were observed in male rats of 15 weeks old. Myocardial degeneration may cause a leakage of potassium into the blood that results in a higher concentration of potassium in the blood in the test group than in that of the control group given tap water.

Influences of alkaline ionized water on milk yield, body weight of offspring and perinatal dam in rats

The authors previously reported that male offspring of mothers rats given alkaline ionized water (AKW) showed a significantly higher body weight by day 14 after birth than did offspring of mother rats given tap water (TPW); furthermore, marked myocardial necrosis and fibrosis were observed particularly in the former male offspring at the age of 15 weeks. In the present experiment we looked for differences in bioparameters, namely the milk yield of mothers and suckled milk volume of the offspring, between the AKW- and the TPW-treated groups in order to reveal the factors which cause the unusual body weight gain in the offspring. Even though we were able to repeat our previous observation (the body weight of the male offspring of the AKW group increased significantly more by day 14 and 20 after birth and of the female by day 20 after birth than did that of the TPW group (p < 0.05), no significant difference was noted in any of the bioparameters, including those related to milk production and consumption. It is thus suspected that the water-hydrated cation, which was transferred either to the fetus through the placenta or to the offspring through the milk, might be the cause of the unusual body weight increase. Since calcium plays an important role in skeletal formation, it is tentatively concluded that the higher calcium concentration of AKW enriched the mother, serum calcium which was transferred to the fetus through the placenta and to the offspring through the milk.

Seroprevalence against Toxoplasma gondii in domiciled cats in Japan

A serological survey with latex agglutination test to detect anti-Toxoplasma gondii antibodies was conducted on 800 serum samples collected from domiciled cats at animal hospitals in various areas of Japan. The overall prevalence was 6.0% (48/800). Among 48 positive individuals, there was no specific distribution of strength of antibody titers; the titers were 1:64 in 8 cats, 1:128 in 12, 1:256 in 8, 1:512 in 10, 1:1,024 in 8 and 1:2,048 in 2. The maximum prevalence was 15.4% in 13 cats at 17-23 yrs old group, whereas all were negative in 58 cats aged 12-16 yrs. The age groups in the order of higher prevalence were 8, 4, 10, 5, 3, and 7 yrs, showing no aging effect to the prevalence. In terms of rearing conditions of those cats, they were classified into 4 groups, i.e., indoor, free, outdoor, and others. The prevalence in the outdoor group (11.1%) was significantly higher (p < 0.05) than that in the free group (4.8%). Epidemiological aspects observed in the domiciled cats were different from those reported in the stray cats.

Experimental infection in SPF kittens with a particular calicivirus strain originally isolated from lion

Two SPF kittens were experimentally infected via the intranasal route with a strain of calicivirus originally isolated from sick lion suffering from vesicular disease. Fever, 40.3 degrees C and 40.7 degrees C, and vesicular formation in tongue and snout were reproduced in both kittens. The infected virus was recovered from nasal, oral and rectal swabs. A longer duration of virus recovery was proved with oral swab samples taken from 1 to 10 and 12 days post infection. This suggests that tongue and oral tissues are the main tissues for virus multiplication.

Distribution of G serotypes and P genotypes of bovine group A rotavirus isolated in Japan

OBJECTIVE

To identify the distribution of G serotype and P genotype of bovine group A rotavirus in Japan.

DESIGN

Detection, isolation, electropherotyping, G serotyping and P genotyping of bovine group A rotavirus in 167 diarrhoeal faecal samples.

PROCEDURE

Bovine group A rotavirus was detected and isolated, and bovine group A rotavirus isolates were identified electropherotype by polyacrylamide gel electrophoresis and G serotype and P genotype by reverse transcription-poly-merase chain reaction.

RESULTS

Twenty-eight bovine group A rotavirus strains were isolated from 167 samples. Electropherotypes of the bovine group A rotavirus isolates were identified as long-genome electropherotype and the most prevalent combination of G serotype and P genotype of the bovine group A rotavirus isolates was G6P5 (25/28; 89.3%), followed by G6P11 (2/28; 7.1%) and G10P11 (1/28; 3.6%).

CONCLUSION

These results suggest that the bovine group A rotavirus exhibiting G6P5 is the most common in Japan.

Construction of recombinant vaccinia virus expressing Rinderpest Virus nucleocapsid protein and its immunogenicity in mice

Recombinant vaccinia virus (rVV) was constructed by inserting Rinderpest Virus (RPV) nucleocapsid (N) protein gene. The rVV expressed RPV-N protein in the rVV-infected cells. The rVV was shown to produce RPV-N-specific antibody in mice.

Immunizing effect of vaccinia virus expressing the nucleoprotein of rinderpest virus on systemic rinderpest virus infection in rabbits

A recombinant vaccinia virus (RVV) expressing the nucleoprotein (NP) of rinderpest virus (RPV) was examined in rabbits for the involvement of the NP protein in protection from the RPV infection. Despite their production of anti-NP antibody, the RVV-immunized rabbits succumbed to the RPV challenge, although there was a slight delay in the onset of disease after the low-dose challenge. On the other hand, the animals immunized with RVV expressing the hemagglutinin (H) protein of the RPV were completely protected. These results indicate that the NP protein might be not so effective as the H protein for the protection against viremic and systemic infection with RPV.

Differential effects of chronic administration of the antidepressants amitriptyline and rolipram on adenylyl cyclase activity

Significant increases were observed in guanylylimidodiphosphate- and fluoride-stimulated adenylyl cyclase activities in synaptic membrane preparations from rat cerebral cortex subsequent to the repeated administration of rolipram and amitriptyline. The potency of GppNHp-dependent inhibition of adenylyl cyclase was decreased by chronic treatment with rolipram but not by amitriptyline treatment. These findings suggest that chronically administered rolipram and amitriptyline share the augmentation of adenylyl cyclase activity by different actions on post-receptor signaling.

Clinical features of ovarian cancer in Japanese women with germ-line mutations of BRCA1

We analyzed the clinical features of 25 ovarian cancer patients who were associated with germ-line mutations of BRCA1 from four site-specific ovarian cancer families and seven breast-ovarian cancer families in Japan. The average age at diagnosis was 51.1 years (range, 38-77 years). Histological examination revealed 24 serous cyst adenocarcinomas in 25 patients. In 23 patients with clear clinical records, 3 patients had stage I disease, 17 had stage III disease, and 3 had stage IV disease. Thirteen patients with stage III disease who were treated with cisplatin-containing chemotherapy following tumor reduction surgery showed more favorable outcomes in both the survival rate and disease-free intervals, compared with age- and treatment course-matched controls (5-year survival rate, 0.786 versus 0.303; median disease-free interval, 91.43 versus 40.92 months; P < 0.05 for both, by logarithmic rank test). Our statistical model for the inheritance of susceptibility to ovarian cancer was derived from the analysis of 26 patients and 19 healthy carriers of 12 families. The expected lifetime risk of ovarian cancer is about 80% for women with mutations of BRCA1. These results suggest that the clinical outcome of ovarian cancer with germ-line mutations of BRCA1 appears to be more favorable than that with sporadic cases and that the disease penetrance among pedigrees with germ-line mutations of the BRCA1 gene is substantially high.

A possible immunosuppressant, cycloprodigiosin hydrochloride, obtained from Pseudoalteromonas denitrificans

Cycloprodigiosin hydrochloride (cPrG.HCl), a member of the prodigiosin family, is a red pigment obtained from the marine bacterium Pseudoalteromonas denitrificans. cPrG.HCl markedly suppressed 3H-thymidine incorporation by concanavalin A stimulated murine splenocytes but had little effect on lipopolysaccharide dependent 3H-thymidine incorporation, indicating that cPrG.HCl acts as a selective inhibitor of T cell proliferation in the same way as other members of the prodigiosin family. cPrG.HCl inhibited the proliferation of the PMA stimulated Jurkat cells through an apoptotic process. Intriguingly, cPrG.HCl inhibited the H+ translocation by vacuolar type ATPase in chromaffin granule membranes without any effect on either its ATPase activity nor on the membrane conductance of phospholipid bilayers, suggesting that cPrG.HCl selectively uncouples H+ translocation from the ATPase reaction rather than acting as a non-specific ionophore. Since crystalline cPrG.HCl is highly stable, it raises the possibility of its therapeutic use as an immunosuppressant.

A strain of calicivirus isolated from lions with vesicular lesions on tongue and snout

In December 1992, 17 African lions and 7 Siberian tigers in a Safari park in Japan became sick with characteristic clinical symptoms of acute vesicular formations on tongue and snout. The disease was highly contagious since all of these animals showed similar symptoms within two days after the onset of the first case. Swabs were taken from affected animals in rubbing tongues, snouts and some from rectums. Cytopathic viruses were isolated on CRFK cell culture by virological tests. The physicochemical property of a representative virus strain, named Arthur/L, isolated from a male lion was identified as a member of Caliciviridae. However, seroneutralization test indicated that this virus strain was antigenically distinct from Japanese isolates of feline caliciviruses used for comparison. Viral capsid proteins of the present isolate, Arthur/L, and of a feline calicivirus, strain FC7, were compared in an electrophoresis in SDS-PAGE gel. The major viral capsid polypeptide of them were proved to be significantly different in molecular weight. The polypeptide of FC7 was estimated to be ca. 63 KDa whereas that of Arthur/L consisted of 2 components of ca. 65 and 62 KDa. The viral proteins of these two strains were also proved to be distinct by an immunoblotting test.

Viral susceptibility of a newly established cell line derived from the peritoneal cavity of BALB/C mouse

Viral susceptibility of a newly established cell line, named KMP, derived from the peritoneal cavity of BALB/C mouse is described. The cells were originally cloned from the in vitro culture of ascites of the mouse injected with Ehrlich ascitic tumor cells in advance. The electrophoretic pattern of cellular DNAs, extracted from KMP, normal BALB/C mouse spleen, and Ehrlich tumor cells respectively were compared after triple digestions with restriction endonucleases. This cell line was proved to be of mouse origin, but not the sub-line of Ehrlich tumor cells. The strains of Coxsackie virus B group, swine enterovirus, influenza virus, encephalomyocarditis virus, vesicular stomatitis virus, and Aujeszky's disease virus were able to multiply well in the cell line with considerably high infectious titers in showing clear CPE and circular plaques.