[Prevalence of Cereulide-Producing Bacillus cereus in Pasteurized Milk]

To recognize the risk of Bacillus cereus in pasteurized milk, we investigated the prevalence of B. cereus and the rate of the production of cereulide from B. cereus isolates. B. cereus was found in 66 out of 101 (65.3%) domestically pasteurized milk samples in Japan. The ces gene was identified in 3 out of 90 B. cereus isolates that were isolated from three samples (one product) among the 101 samples. The ces gene positive isolate, the reference strain F4810/72 and a B. cereus isolate collected in a food poisoning incident were shown the productivity of cereulide using an LC-MS/MS analysis. The LC-MS/MS analysis was confirmed the ability of identification and quantification of cereulide produced in the milk samples. In this study, it was shown that B. cereus strains are prevalent in pasteurized milk, some of these strains produce cereulide, and confirmed usefulness of LC-MS/MS analysis to detect cereulide in milk.

Quantification of staphylococcal enterotoxin type A in cow milk by using a stable isotope-labelled peptide via liquid chromatography-tandem mass spectrometry

In this study, the staphylococcal enterotoxin type A (SEA) contaminant was quantified in cow milk by liquid chromatography-tandem mass spectrometry (LC-MS/MS) with the use of a stable isotope-labelled peptide of SEA as an internal standard. SEA was cleaned up in a two-step process that included pH control and trichloroacetic acid (TCA) precipitation. The pH control phase eliminated other proteins. TCA precipitation cleaned up SEA without special equipment. An appropriate enzyme-to-protein ratio maximised tryptic digestion. A desalting process guaranteed the stable retention of SEA-digested peptides. The coverage of amino-acid sequences (>10%) clearly identified the toxin's presence. SEA was accurately quantified using LC-MS/MS based on a multiple-reaction monitoring mode. The developed method was validated based on spiked recovery tests at 50 and 100 µg kg^-1 conducted with two samples collected on a daily basis for five days based on Japanese validation guidelines. The new method exhibited good accuracy which ranged from 80% to 82%. The relative standard deviations of repeatability were 13-14% and the relative standard deviations of within-laboratory reproducibility were 13-18%. These standard deviations satisfied the criteria of the Japanese validation guidelines. The quantification limit was estimated to be 10 µg kg^-1.

Comparison between patients with norovirus-related gastroenteritis and asymptomatic carriers with respect to distribution of antibody-complexed viral particles and intestinal flora

Asymptomatic carriers have a major influence on the spreading of norovirus infections. The objective of this study was to examine the characteristics of patients and asymptomatic carriers affected by norovirus-related community gastroenteritis outbreaks. No significant difference between the two groups was observed in terms of the number of norovirus-antibody complexes with respect to total numbers. Principal coordinates analysis of the intestinal flora based on β-diversity analysis, revealed a different bacterial composition between patients and asymptomatic carriers, particularly regarding the genera Pseudomonas, Bacteroides, and Erwinia, as well as the Ruminococcaceae family. Although the proportional changes between these intestinal microorganisms were not sufficient to explain gastroenteritis symptoms, they represent possible markers shared by asymptomatic norovirus carriers.

Detection of the mcr-1 gene in colistin-resistant Escherichia coli from retail meat in Japan

In this study, the presence of the mcr-1 gene in Escherichia coli from retail meat in Japan was investigated. Nine E. coli isolates (eight from chickens and one from pork) carried the mcr-1 gene on the plasmid. In six isolates from domestic chickens, mcr-1 was located on the IncI2 plasmid, which is approximately 60 kb in size. In the remaining three isolates from imported chicken and pork, mcr-1 was located on the IncX4 plasmid (30 kb).

Effect of the Infusion of OKY-046, a Thromboxane A2 Synthase Inhibitor, on Urinary Metabolites of Prostacyclin and Thromboxane A2 in Healthy Human Subjects

The influence of OKY-046, a selective thromboxane synthase inhibitor, on prostanoid formation in healthy human subjects was studied. Vehicle (5% glucose solution) or OKY-046 in 5% glucose solution at 15 μg kg−1 min−1 was intravenously administered to five male healthy volunteers for 6 h. Platelet aggregation and thromboxane B2 (TXB2) formation induced by collagen and arachidonic acid were suppressed by the infusion of OKY-046, while both were not affected by the infusion of vehicle. Urinary excretion of 11-dehydro-thromboxane B2, one of major urinary metabolites of thromboxane A2 (TXA2) was decreased by the infusion of OKY-046, while that of 2,3-dinor-6-keto-prostaglandin F1α, one of major urinary metabolites of prostacyclin (PGI2) was increased. The present study demonstrated that the infusion of OKY-046 improved the balance of TXA2/PGI2 into antithrombotic state in healthy subjects. It was also suggested that endogenously produced (probably platelet-derived) endoperoxides could be redirected into prostacyclin in vivo.

[Serial Food Poisoning Outbreaks Caused by Norovirus-Contaminated Shredded Dried Laver Seaweed Provided at School Lunch, Tokyo, 2017]

In February 2017, four food poisoning outbreaks occurred in Tokyo, involving ten schools. Shredded dried laver seaweed processed by a single food manufacturer in December 2016 was provided in common for the school meals that caused all four outbreaks. Of 4,209 persons exposed, 1,193 (28.3%) had symptoms of gastroenteritis. Norovirus (NoV) GII was detected in 207 (78.1%) of 265 cases by real-time RT-PCR. Thirty-one shredded dried laver seaweed samples were examined and seven (22.6%) of them were positive for NoV GII. PCR fragments of NoV ORF1/2 junction region (302 bp) from seven shredded dried laver seaweed samples and 20 clinical samples derived from the four outbreaks were sequenced. All of them displayed complete homology, and the genotype was classified as GII.17. A nearly full-length sequence (7,420 bp) of NoV RNA derived from a case was obtained by next-generation sequencer analysis and phylogenetic analysis indicated that this strain belongs to the same cluster as Hu/GII/JP/2015/GII.P17_GII.17/Kawasaki308. Thus, our investigation elucidated that the causative agent of these four serial food poisoning outbreaks was NoV GII.17 and the infectious source was a single batch of shredded dried laver seaweed. The water activity of the shredded dried laver seaweed was found to be 0.119 to 0.129. It was epidemiologically clarified that NoV does not lose infectivity for about two months even in the dry state. We conclude that a large diffuse outbreak of food poisoning caused by NoV GII.17 contamination of shredded dried laver seaweed had occurred in Tokyo. Our elucidation of the causative agent indicated that the food poisoning outbreaks in multiple areas of Japan, including Tokyo, during January to February 2017 were caused by the same contaminated food.

Identification and functional activity of a staphylocoagulase type XI variant originating from staphylococcal food poisoning isolates

Staphylocoagulase, an extracellular protein secreted by Staphylococcus aureus, has been used as an epidemiological marker. At least 12 serotypes and 24 genotypes subdivided on the basis of nucleotide sequence have been reported to date. In this study, we identified a novel staphylocoagulase nucleotide sequence, coa310, from staphylococcal food poisoning isolates that had the ability to coagulate plasma, but could not be typed using the conventional method. The protein encoded by coa310 contained the six fundamental conserved domains of staphylocoagulase. The full-length nucleotide sequence of coa310 shared the highest similarity (77·5%) with that of staphylocoagulase-type (SCT) XIa. The sequence of the D1 region, which would be responsible for the determination of SCT, shared the highest similarity (91·8%) with that of SCT XIa. These results suggest that coa310 is a novel variant of SCT XI. Moreover, we demonstrated that coa310 encodes a functioning coagulase, by confirming the coagulating activity of the recombinant protein expressed from coa310. This is the first study to directly demonstrate that Coa310, a putative SCT XI, has coagulating activity. These findings may be useful for the improvement of the staphylocoagulase-typing method, including serotyping and genotyping.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first study to identify a novel variant of staphylocoagulase type XI based on its nucleotide sequence and to demonstrate coagulating activity in the variant using a recombinant protein. Elucidation of the variety of staphylocoagulases will provide suggestions for further improvement of the staphylocoagulase-typing method and contribute to our understanding of the epidemiologic characterization of Staphylococcus aureus.

[Two Outbreaks of Yersinia enterocolitica O:8 Infections in Tokyo and the Characterization of Isolates]

Although the number of outbreaks caused by Yersinia enterocolitica has been very small in Japan, 4 outbreaks were occurred during the 2 years between 2012 and 2013. We describe herein 2 outbreaks which were examined in Tokyo in the present study. Outbreak 1: A total of 39 people (37 high school students and 2 staff) stayed at a hotel in mountain area in Japan had experienced abdominal pain, diarrhea and fever in August, 2012. The Y. enterocolitica serogroup O:8 was isolated from 18 (64.3%) out of 28 fecal specimens of 28 patients. The infection roots could not be revealed because Y. enterocolitica was not detected from any meals at the hotel or its environment. Outbreak 2: A total of 52 students at a dormitory had diarrhea and fever in April, 2013. The results of the bacteriological and virological examinations of fecal specimens of patients showed that the Y. enterocolitica serogroup O:8 was isolated from 24 fecal specimens of 21 patients and 3 kitchen staff. We performed bacteriological and virological examination of the stored and preserved foods at the kitchen of the dormitory to reveal the suspect food. For the detection of Y. enterocolitica, food samples. together with phosphate buffered saline (PBS) were incubated at 4 degrees C for 21 days. Then, a screening test for Y. enterocolitica using realtime-PCR targeting the ail gene was performed against the PBS culture. One sample (fresh vegetable salad) tested was positive on realtime-PCR. No Y. enterocolitica was isolated on CIN agar from the PBS culture because many bacteria colonies other than Y. enterocolitica appeared on the CIN agar. After the alkaline-treatments of the culture broth or the immunomagnetic beads concentration method using anti-Y. enterocolitica O:8 antibodies, Y. enterocolitica O:8 which was the same serogroup as the patients' isolates was successfully isolated from the PBS culture. The fresh vegetable salad was confirmed as the incrimination food of this outbreak.

Prevalence and contamination levels of listeria monocytogenes in ready-to-eat foods in Tokyo, Japan

We surveyed prevalence and contamination levels of Listeria monocytogenes in ready-to-eat foods between 2000 and 2012 in Tokyo. L. monocytogenes was isolated from 52 (1.7%) out of 2,980 samples. Comparing the prevalence in the study period, 2.2% were positive in the former period (2000-2005) and 1.2% in the latter (2006-2012). Using the most probable number (MPN) technique, 32 samples were contaminated with fewer than 0.3 L. monocytogenes/g, 10 samples with 0.3-1.0/g and 4 samples with more than 1.0/g (the maximum was 2.3/g). The most common serovar was 1/2a, followed by 1/2b, 4b and 1/2c. We revealed that ready-to-eat foods in Tokyo were contaminated with L. monocytogenes, although the contamination levels were low.

Multiplex PCR serogrouping of Listeria monocytogenes isolated in Japan

PCR serogrouping methods were used to examine strains of L. monocytogenes isolated in Japan. Among 187 strains, 99.5% were classified into 4 PCR serogroups corresponding to conventional serotypes. Only one isolate had a new PCR profile, which may be a variant of serogroup IVb.

Development of a method for detecting Coxiella burnetii in cheese samples

Coxiella burnetii is the causative agent of Q fever, and the main route of infection in humans is inhalation of contaminated aerosols. Although oral transmission by contaminated raw milk or dairy products is also a possible route of human infection, there have been few studies investigating the presence of C. burnetii in dairy products. We developed a new method of extracting DNA from cheese and detecting C. burnetii DNA in cheese samples with a nested PCR assay. The limit of detection was 6.0 × 10(2) C. burnetii particles per gram. We subsequently used this method to examine the presence of C. burnetii in cheese at commercial markets in Tokyo from June 2005 to December 2008. Twenty-eight of 147 cheese samples were found to be positive for C. burnetii DNA. However, when we assessed the viability of C. burnetii by inoculating mice with DNA-positive samples, all of the samples were found to be negative. Thus, the viability of C. burnetii appears to have been lost in these cheese samples.

[Development of effective detection method for Coxiella burnetii in mayonnaise by real-time PCR and investigation of C. burnetii contamination in commercial mayonnaise in Tokyo]

A PCR method for the effective detection of Coxiella burnetii in commercially available mayonnaise was developed. Sample preparations were isolated from 50 g portions of each mayonnaise product by four successive extraction steps in phosphate buffer with 2.0 M NaCl. These extracts were then centrifuged at 20,000 x g for 60 min. DNA was isolated from the solution containing the precipitate with a commercial kit, and amplified quantitatively using real-time PCR that targeted the com1 region of C. burnetii. The recoveries of C. burnetii from 2 kinds of commercial mayonnaise specimens, with a baseline control of 1 x 10(7) particles of the Nine Mile phase II strain, were 85.0 +/- 6.0% and 72.0 +/- 0.4%, respectively. The determination limit of this method was 500 C. burnetii particles per 50 g of mayonnaise. The DNA specimens isolated from 50 different commercial mayonnaise samples sold in Tokyo using this method were amplified using both nested PCR and real-time PCR. No contamination by C. burnetii was detected in any of the mayonnaise samples.

Acute monocytic leukaemia in a cat

A three-year-old cat with lymphadenopathy, non-regenerative anaemia and marked leucocytosis (171.3 x 10(9) white blood cells/l) was diagnosed with monocytic leukaemia and treated with a combination of anticancer drugs. A number of mature and immature monocyte-like cells were detected in the peripheral blood and bone marrow; they proved to be monocytic cells by cytochemical examination and an analysis of their cell surface phenotype, indicating that the cat suffered from acute myeloid leukaemia, subclassified as monocytic leukaemia (M5). Treatment with cytarabine, doxorubicin, vincristine and prednisolone greatly reduced the number of blast cells in the cat's peripheral blood and bone marrow. The cat was in partial remission for 67 days and survived for 95 days after it was first examined.

[Investigation of Coxiella burnetii contamination in commercial milk and PCR method for the detection of C. burnetii in egg]

A total of 244 milk samples collected from supermarkets in Tokyo were examined for contamination with Coxiella burnetii. C. burnetii DNA was detected in 131 (53.7%) of the samples by nested PCR. PCR-positive samples were injected into immunosuppressed A/J strain mice. Of the 22 PCR-positive milk samples tested, none resulted in isolation of C. burnetii from the mice. Heat-treatment was sufficient to inactivate C. burnetii in commercial milk. In addition, a PCR detection method for C. burnetii in chicken egg was developed. Egg yolk was added to an equal volume of 1 mol/L of NaCl phosphate buffer and homogenized for removal of protein and lipid. After centrifugal separation, the supernatant was removed, and template DNA in the precipitate was extracted using SDS, proteinase K and NaI. Using such prepared samples, 3.2 x 10(1) C. burnetii particles in 1 g of egg yolk could be detected by nested PCR. All of 200 chicken egg samples collected from supermarkets in Tokyo were negative for C. burnetii by the nested PCR method.

The complete nucleotide sequence and multipartite organization of the tobacco mitochondrial genome: comparative analysis of mitochondrial genomes in higher plants

Tobacco is a valuable model system for investigating the origin of mitochondrial DNA (mtDNA) in amphidiploid plants and studying the genetic interaction between mitochondria and chloroplasts in the various functions of the plant cell. As a first step, we have determined the complete mtDNA sequence of Nicotiana tabacum. The mtDNA of N. tabacum can be assumed to be a master circle (MC) of 430,597 bp. Sequence comparison of a large number of clones revealed that there are four classes of boundaries derived from homologous recombination, which leads to a multipartite organization with two MCs and six subgenomic circles. The mtDNA of N. tabacum contains 36 protein-coding genes, three ribosomal RNA genes and 21 tRNA genes. Among the first class, we identified the genes rps1 and psirps14, which had previously been thought to be absent in tobacco mtDNA on the basis of Southern analysis. Tobacco mtDNA was compared with those of Arabidopsis thaliana, Beta vulgaris, Oryza sativa and Brassica napus. Since repeated sequences show no homology to each other among the five angiosperms, it can be supposed that these were independently acquired by each species during the evolution of angiosperms. The gene order and the sequences of intergenic spacers in mtDNA also differ widely among the five angiosperms, indicating multiple reorganizations of genome structure during the evolution of higher plants. Among the conserved genes, the same potential conserved nonanucleotide-motif-type promoter could only be postulated for rrn18-rrn5 in four of the dicotyledonous plants, suggesting that a coding sequence does not necessarily move with the promoter upon reorganization of the mitochondrial genome.

The complete sequence of the rice (Oryza sativa L.) mitochondrial genome: frequent DNA sequence acquisition and loss during the evolution of flowering plants

The entire mitochondrial genome of rice (Oryza sativa L.), a monocot plant, has been sequenced. It was found to comprise 490,520 bp, with an average G+C content of 43.8%. Three rRNA genes, 17 tRNA genes and five pseudo tRNA sequences were identified. In addition, eleven ribosomal protein genes and two pseudo ribosomal protein genes were found, which are homologous to 13 of the 16 genes for ribosomal proteins in the mitochondrial genome of the liverwort (Marchantia polymorpha). A greater degree of variation in terms of presence/absence and integrity of genes was observed among the ribosomal protein genes and tRNA genes of rice, Arabidopsis and sugar beet. Transcription and post-transcriptional modification (RNA editing) in the rice mitochondrial sequence were also examined. In all, 491 Cs in the genomic DNA were converted to Ts in cDNA. The frequency of RNA editing differed markedly depending upon the ORF considered. Sequences derived from plastid and nuclear genomes make up 6.3% and 13.4% of the mitochondrial genome, respectively. The degree of conservation of plastid sequences in the mitochondrial genome ranged from 61% to 100%, suggesting that sequence migration has occurred very frequently. Three plastid DNA fragments that were incorporated into the mitochondrial genome were subsequently transferred to the nuclear genome. Nineteen fragments that were similar to transposon or retrotransposon sequences, but different from those found in the mitochondrial genomes of dicots, were identified. The results indicate frequent and independent DNA sequence flow to and from the mitochondrial genome during the evolution of flowering plants, and this may account for the range of genetic variation observed between the mitochondrial genomes of higher plants.

Chitin synthase 1 gene of Arthroderma benhamiae isolates in Japan

In the present study, the chitin synthase 1 (CHS1) gene of eight clinical isolates of Arthroderma benhamiae in Japan was investigated. Nucleotide sequence analysis of the CHS1 gene fragments from clinical isolates of A. benhamiae and from standard strains of Americano-European race and African race A. benhamiae indicated more than 90% similarities among these dermatophytes. An especially high degree of similarity was noted in nucleotide sequence CHS1 gene fragments, with more than 99% among eight clinical isolates and standard strains of the Americano-European race of A. benhamiae. The phylogenetic analysis of their sequences revealed that the eight clinical isolates and the standard strains of the Americano-European race of A. benhamiae were included in the same cluster, and that the African race of A. benhamiae formed a cluster that was distinct from the Americano-European race of A. benhamiae, A. simii and A. vanbreuseghemii.

Molecular identification of Trichophyton rubrum isolate from a dog by chitin synthase 1 (CHS1) gene analysis

A nonsporulating isolate from a dog with dermatophytosis was identified as Trichophyton rubrum by molecular analysis. The nucleotide sequence analysis of the chitin synthase 1 (CHS1) gene from the isolate indicated more than 99% sequence similarity with other human and canine isolates of T rubrum. The molecular typing suggested that isolates of T. rubrum from human and canine sources were genetically identical.

[Troubles inherent to long-term home parenteral nutrition (HPN) and the use of technologies to improve communication between medical institutions and patients]

The continuous advance of technology has contributed to the improvement of the quality of life of patients under long-term home parenteral nutrition (HPN). But the longer the patient stays home, the higher the risk of many kinds of troubles. We designed an HPN system in June 1999, which uses E-mail for patients and to contact with each other (including the patient's family) and to prevent troubles from worsening. We describe the case of a patient which shows the efficacy and usefulness of our system, which makes use of the Internet, video mail, voice mail and electric medical records.

Dominant-negative mutation of p53 tumor suppressor gene in endometrial carcinoma

BACKGROUND

It has been suggested that mutation of the TP53 tumor suppressor gene is involved in endometrial carcinogenesis. However, the status of p53 function in endometrial cancers has not yet been investigated in detail.

METHODS

We surveyed inactivating p53 mutations in endometrial carcinomas using the yeast p53 functional assay, which can evaluate the transcriptional activity of p53 in vivo in yeast. To the detected p53 mutants, we also applied a transdominance assay, which assesses the dominant-negative property of mutants.

RESULTS

Of 23 endometrial carcinomas, 9 tumors (39.1%) were found to harbor p53 mutations. Only 1 of the 6 mutants in 18 endometrioid-type tumors showed dominant-negative capacity. In contrast to the endometrioid-type tumor, all 3 mutations in 5 serous-type tumors (R273H, 9-bp deletion in codons 240-243, and R248W) showed dominant-negative capacity and presented in a homozygous state in the tumors, indicating a complete functional inactivation.

CONCLUSIONS

Although this study included a relatively small number of cases and therefore is a preliminary study, these results suggest that the dominant-negative mutation of the TP53 gene is related to serous adenocarcinoma. The role of the dominant-negative status of p53 mutants in endometrial carcinogenesis and progression of this disease should be further investigated.

A case of POEMS syndrome with high concentrations of interleukin-6 in pericardial fluid

The POEMS syndrome (plasma cell dyscrasia with polyneuropathy, organomegaly, endocrinopathy of various forms, monoclonal gammopathy, skin changes) is a rare multisystem disorder of unknown pathogenesis. Overexpression of proinflammatory cytokines has been implicated in the pathogenesis of POEMS syndrome, however, it is not known whether there is an association between abnormalities in cytokines and pericardial fluid. We present a case of POEMS syndrome with high concentrations of interleukin-6 (IL-6) in pericardial fluid. In our patient, pericarditis developed into cardiac tamponade, and the concentration of IL-6 in pericardial fluid was remarkably elevated compared with that in serum (1760 vs. 6.57 pg mL(-1)). We suggest that IL-6 is associated with the progression or maintenance of pericarditis as a result of POEMS syndrome.

Diabetic ketoacidosis associated with recurrent pulmonary edema and rhabdomyolysis in a patient with Turner's syndrome

Turner's syndrome is a condition involving total or partial absence of one X chromosome and has been associated with a number of diseases including non insulin dependent diabetes mellitus, abnormalities of glucose metabolism and hypothreosis. There have been many case reports in which Turner's syndrome is associated with type 2 diabetes, but the association with type 1 diabetes and/or life threatening complications is very rare. We present an unusual case of a patient with Turner's syndrome who has type 1 diabetes and is complicated with ketoacidosis, severe acute and recurrent pulmonary edema and rhabdomyolysis.

Multiple oral squamous epithelial lesions: are they genetically related?

The development of second primary tumors (SPTs) in patients with head and neck squamous cell carcinoma (HNSCC) has become an increasingly important factor in clinical treatment decisions. Currently, clinical and histologic parameters are used to determine whether or not SPT is present. Recent studies suggest that many SPTs in the upper aerodigestive tract have a common clonal origin, challenging the longstanding multiclonal origin concept. To determine genetic relationships among multiple oral cancerous and precancerous lesions (MOCP), we analysed 100 lesions from 26 Japanese patients. Lesion development was synchronous and metachronous. We looked for patterns of microsatellite alterations (MA) using seven markers at chromosomes 3p14, 9p21, and 17p13, where MA occurs early in oral carcinogenesis. Loss of heterozygosity (LOH) was found in 52.6% (41/78), 62.5% (60/96), and 59.3% (32/54) of informative MOCP at 3p14, 9p21, and 17p13, respectively. Microsatellite instability (MI) was observed in 11, 26 and 13% of the samples at 3p14, 9p21, and 17p13 markers, respectively. Patterns of MA were concordant in only nine (14%) of 63 lesions from four (18%) of 22 patients who initially presented with noninvasive lesions. However, two of four patients with invasive cancer as indexed lesion showed 16 (43%) clonally related MOCP among 37 lesions (P=0.003). The results suggest that the majority of MOCP arise from clonally independent cells affected by field cancerization. However, the probability of mucosal spread of clonal malignant or premalignant cells may increase along with malignant progression.

Interaction of MCC2, a novel homologue of MCC tumor suppressor, with PDZ-domain Protein AIE-75

AIE-75 is a protein identified as an autoantigen in patients with autoimmune enteropathy and as a colon cancer-related antigen. It has recently been assigned to be a causative gene for Usher type 1C congenital syndromic hearing loss. The novel protein has three PSD-95/Dlg/ZO-1 (PDZ) protein-protein interaction domains and is therefore implicated to function as a molecular anchor or sorter. We have identified a novel protein that binds to AIE-75 by yeast two-hybrid screening. The protein has a high homology to the tumor suppressor MCC (mutated in colon cancer; or MCC1 hereafter) and was named MCC2. MCC2 protein binds the first PDZ domain of AIE-75 with its C-terminal amino acids -DTFL. Since the MCC1 does not bind to AIE-75 and the MCC2 displays different expression patterns in various organs compared to MCC1, they appear to play distinct roles in cells. The MCC2 gene is located on chromosome 19p13 in the vicinity of APCL gene, while MCC1 maps near to APC tumor suppressor gene. Because of negative expression of MCC2 in a panel of cancer cell-lines compared to the corresponding normal tissues, we suggest that further study is necessary to investigate a possible role of MCC2 as a tumor suppressor.

Fulminant Mycoplasma pneumoniae pneumonia

A 64-year-old woman, who was previously in good health was admitted because of progressive respiratory distress. Her chest radiograph revealed bilateral widespread alveolar infiltrates. She was given a diagnosis of pneumonia caused by Mycoplasma pneumoniae serologically, acute respiratory distress syndrome, and disseminated intravascular coagulation. She died of multiple organ failure despite intensive therapy with mechanical ventilation, intravenous erythromycin and corticosteroids, continuous hemodiafiltration, and plasma exchange. Although Mycoplasma pneumoniae infection is usually a benign self-limited disease, this case emphasizes its potentially serious nature even in normal healthy individuals.

The gene for alternative oxidase-2 (AOX2) from Arabidopsis thaliana consists of five exons unlike other AOX genes and is transcribed at an early stage during germination

We investigated the expressions of genes for alternative oxidase (AOX1a, AOX1b, AOX1c and AOX2) and genes for cytochrome c oxidase (COX5b and COX6b) during germination of Arabidopsis thaliana, and examined oxygen uptakes of the alternative respiration and the cytochrome respiration in imbibed Arabidopsis seeds. A Northern blot analysis showed that AOX2 mRNA has already accumulated in dry seeds and subsequently decreased, whereas accumulation ofAOX1a mRNA was less abundant from 0 hours to 48 hours after imbibition and then increased. The increase of the capacity of the alternative pathway appeared to be dependent on the expressions of both AOX2 and AOX1a. On the other hand, steady-state mRNA levels of COX5b and COX6b were gradually increased during germination, and the capacity of the cytochrome pathway was correlated with the increase of expressions of the COX genes. Antimycin A, the respiratory inhibitor, strongly increased the expression of AOX1a but had no effect on the expression of AOX2. A 5'RACE analysis showed that AOX2 consists of five exons, which is different from the case of most AOX genes identified so far. Analysis of subcellular localization of AOX2 using green fluorescent protein indicated that the AOX2 protein is imported into the mitochondria.

Regulation of FRTL-5 thyroid cell growth by phosphatidylinositol (OH) 3 kinase-dependent Akt-mediated signaling

Thyrotropin (TSH)-initiated cell cycle progression from G1 to S phase in FRTL-5 thyroid cells requires serum, insulin, or insulin-like growth factor 1 (IGF-1) and involves activation of 3-hydroxy-3-methylglutaryl-CoA reductase, geranylgeranylation of RhoA, p27Kip1 degradation, and activation of cyclin-dependent kinase (cdk) 2. In the present report, we show that the serine-threonine kinase Akt is an important mediator of insulin/IGF-1/serum effects on cell cycle progression in FRTL-5 thyroid cells. The phosphoinositol (OH) 3 kinase inhibitors, Wortmannin (WM) and Ly294002 (LY), block the ability of insulin/IGF-1 to reduce p27 expression, to induce expression of cyclins E, D1, and A as well as cdk 2 and 4, and to phosphorylate retinoblastoma protein. They also inhibit insulin/IGF-1-increased DNA synthesis and cell cycle entrance (S+G2/M). Insulin/IGF-1 rapidly induced activation of Aktl in a PI3 kinase-dependent manner, and increased Aktl RNA levels. Most importantly, FRTL-5 cells transfected with a constitutively active form of Aktl have higher basal rates of DNA synthesis and no longer require exogenous insulin/IGF-1 or serum for TSH-induced growth. In sum, Aktl appears to have an important role in insulin/IGF-1 regulation of FRTL-5 thyroid cell growth and cell cycle progression.

New eudesmane sesquiterpenes from the root of Lindera strychnifolia

Strychnistenolide (1) and its acetate 2 were isolated from the root of Lindera strychnifolia, along with a novel rearranged type of secoeudesmane, strychnilactone (3). Their structures were elucidated by extensive analysis of their NMR spectra, including 2D NMR techniques, together with an X-ray analysis for 3. Strychnistenolide exists as a single stereoisomer in CHCl(3), but in pyridine is epimerized.

Inactivate the remaining p53 allele or the alternate p73? Preferential selection of the Arg72 polymorphism in cancers with recessive p53 mutants but not transdominant mutants

Several reports have noted epidemiological differences in the prevalence or prognostic significance of p53 mutants with arginine (R) or proline (P) at the codon 72 polymorphism (R72/P72) in certain cancer types, but the biological significance of these variants is unclear. The ability of p53 mutants to interact with and inactivate the p53 homolog p73 was recently reported to depend on the conformational state of the p53 protein and the residue at codon 72. Since the conformation of p53 mutants may influence their ability to transdominantly inhibit wild-type p53, we tested whether there was a correlation between the amino acid at codon 72 and the transdominance of p53 alleles found in tumors. The transdominance test was performed using a simple yeast transcription assay, and the amino acid at codon 72 was determined by sequencing. A total of 100 p53 mutants were tested. Compared with the germline frequency (R:P = 427:297), an extreme bias in favor of the R72 allele was observed with recessive mutants (R:P = 50:7, P < 0.0002), whereas no selection for the R72 allele was seen with transdominant mutants (R:P = 23:20). p53 and p73 are known to transactivate overlapping sets of target genes. We interpret the R72 bias with recessive mutants as evidence that decreased activation of p53 target genes provides a selective growth advantage to tumor cells during the stage of tumorigenesis in which a wild-type and mutant p53 allele coexist. We suggest that transdominant p53 mutants achieve this by inactivation of the remaining wild-type p53 allele, whereas recessive p53 mutants achieve it through inactivation of p73.

Characterization and expression of the genes for cytochrome c oxidase subunit VIb (COX6b) from rice and Arabidopsis thaliana

Many of the subunits of cytochrome c oxidase (COX) in the mitochondria of higher plants are encoded by nuclear genes. These genes are less characterized compared to mitochondrial-encoded genes. We previously isolated a cDNA encoding COX6b (designated OsCOX6b1 in this study) from the rice nuclear genome and analyzed its expression. The deduced protein had an extended N-terminus compared with human and yeast COX6b proteins. In this study, we identified another COX6b gene (OsCOX6b2) in rice and revealed that it was actually expressed. The deduced protein of this gene did not have an extended N-terminus and had about the same size as the human and yeast proteins. Genomic Southern hybridization analysis revealed that there was at least one OsCOX6b-homologus sequences in the rice genome other than OsCOX6b1 and OsCOX6b2. Furthermore, we identified three COX6b genes in a dicotyledonous plant, Arabidopsis thaliana. One of these genes (AtCOX6b1) was relatively long, with a length similar to that of OsCOX6b1, and the other two (AtCOX6b2 and AtCOX6b3) were shorter, with lengths similar to the length of OsCOX6b2. Genomic Southern hybridization analysis indicated there were no additional COX6b genes in the Arabidopsis genome. The coding regions of OsCOX6b1 and AtCOX6b1 were separated by four introns and those of OsCOX6b2, AtCOX6b2 and AtCOX6b3 were separated by three introns. A Northern hybridization analysis showed that OsCOX6b1, AtCOX6b1 and AtCOX6b3 were expressed in all organs examined, although with some differences in the amount of expression among the organs. OsCOX6b2 and AtCOX6b2 were strongly expressed in roots but most of the transcripts of AtCOX6b2 were degraded. The evolution of COX6b genes from rice and Arabidopsis is discussed.

Numerous and highly developed tubular projections from plastids observed in Tobacco epidermal cells

Tubular projections from plastids (stromules) were observed using a stroma-targeted green fluorescent protein (GFP) fusion protein and a confocal laser scanning microscope. In tobacco (Nicotiana tabacum) epidermal cells, stromules were observed at a high frequency. Some of them were long and connected plastids. Three days after particle bombardment, 80.6+/-6.99% of the transformed cells contained some plastids with more than one stromule, and 40.2+/-7.7% contained at least one pair of plastids connected by stromules. In a few cells, numerous and highly developed stromules covering the whole cell were observed. Stromules were also observed in epidermal cells in each of three other plant species that were tested: rice, dayflower (Commelina communis) and Arabidopsis thaliana. These findings demonstrated that stromules are common structure in plant epidermal cells.

Murine homologs of deltex define a novel gene family involved in vertebrate Notch signaling and neurogenesis

Notch signaling plays an important role in cell-fate specification in multicellular organisms by regulating cell-cell communication. The Drosophila deltex gene encodes a modulator of the Notch pathway that has been shown to interact physically with the Ankyrin repeats of Notch. We isolated four distinct cDNAs corresponding to mouse homologs of deltex - mouse Deltex1 (MDTX1), mouse Deltex2 (MDTX2), mouse Deltex2DeltaE (MDTX2DeltaE), and mouse Deltex3 (MDTX3). Deduced amino acid sequences of these four cDNAs showed a high degree of similarity to Drosophila Deltex and its human homolog, DTX1 throughout their lengths, even though they possess distinct structural features. MDTX proteins formed homotypic and heterotypic multimers. We found that these genes were expressed in the central, peripheral nervous system and in the thymus, overlapping with those of mouse Notch1. In mammalian tissue culture cells, overexpression of any of the four mouse deltex homologs suppressed the transcriptional activity of E47, a basic helix-loop-helix (bHLH) protein, in a manner similar to suppression by an activated form of human Notch1 or human DTX1. In addition, overexpression of MDTX2 and MDTX2DeltaE in C2C12 cells under differentiation-inducing conditions suppressed the expression of myogenin, one of the myogenic transcriptional factors; this was also similar to a previously reported activity of constitutively activated Notch. Furthermore, misexpression of any of the MDTX genes in Xenopus embryos resulted in an expansion of the region expressing the neural cell adhesion molecule (N-CAM) gene, a marker for the neuroepithelium. Collectively, our results suggest that these mouse deltex homologs are involved in vertebrate Notch signaling and regulation of neurogenesis.

Development of squamous cell carcinoma from pre-existent oral leukoplakia: with respect to treatment modality

The present study was undertaken in order to determine whether surgical treatment of oral leukoplakia reduces the risk of the subsequent development of carcinoma. This study included 142 patients with oral leukoplakia who received or did not receive surgical treatment. All subjects were followed-up for more than 6 months with a mean follow-up period of 4 years. Malignant transformation rate was lower among patients who received surgical excision (1/75) than among those who did not receive surgical treatments (4/51). However, the malignant transformation rates were high in patients who received cryosurgery (3/12) or cryosurgery plus surgical excision (1/4). There was no obvious relation between the grade of epithelial dysplasia and the rate of malignant transformation. Our results suggest that surgical excision of oral leukoplakia may reduce the risk of the subsequent development of carcinoma.

Maxadilan specifically interacts with PAC1 receptor, which is a dominant form of PACAP/VIP family receptors in cultured rat cortical neurons

Maxadilan is a potent vasodilator peptide isolated from salivary gland extracts of the hematophagous sand fly. Recently, the possibility was demonstrated that maxadilan binds to PAC1 receptor (PACAP, pituitary adenylate cyclase activating polypeptide type I receptor) in mammals. In the present study, we demonstrated that: (1) maxadilan specifically binds to PAC1 receptor and stimulates cyclic AMP accumulation in a dose-dependent manner in CHO cells stably expressing PAC1 receptor, not VIP (vasoactive intestinal polypeptide) receptors; that (2) the deleted peptide (amino acid #24-42) of maxadilan (termed max.d.4) also specifically binds to PAC1 receptor although max.d.4 inhibits cyclic AMP accumulation stimulated by both maxadilan and PACAP; and that (3) max.d.4 completely blocks the cyclic AMP accumulation induced by VIP in cultured rat cortical neurons. The expression of specific PACAP receptors in cultured rat cortical neurons was further investigated by the reverse transcription-polymerase chain reaction technique, which showed the presence of mRNA coding for PAC1 receptor among PACAP/VIP family receptors. These data indicate that maxadilan and max.d.4 represent important tools for clarifying the physiological role of PAC1 receptor, and that PAC1 receptor plays an important role in the regulation of the functions induced by PACAP in rat cultured cortical neurons.

[A case of terminal cancer patient whom the home staying terminal cares were provided with ease supported by the regional core hospital]

A physician who practices generally at his private clinic will be sometimes referred to a cancer patient staying at home. This referral is hardly acceptable without helps from other medical and paramedical specialities. He needs a support organization in which a supporting hospital is the most important. A case of home staying terminal cancer patient is reported here whom a private practician provided terminal cares with great difficulties at the beginning and afterwards with no significant difficulties organizing a care team for the home staying patient and assisted by a supporting hospital.

[Home infusion therapy system from a resident's point of view]

We started a new home infusion therapy system in July 1999. The home infusion therapy system is made up of doctors, nursing stations, and pharmacies in the community. We coordinate these parties before patient discharge from our hospital and support them when the patient needs hospitalization (for example, he or she develops pneumonia). This report discusses past experiences and future issue.