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Biomedical subjects

N Takada

Publications and source records attributed to N Takada.

At least 37 records · Page 2Linked to original sources
PubMed2001

Promotion of chemically induced rat esophageal tumorigenesis with post-initiation ethanol modification.

Post-initiation ethanol modification on N-nitrosomethylbenzylamine (NMBA)-induced rat esophageal carcinogenesis model was investigated in male, 6-week-old, F344 rats that received s.c. injections, 3 times per week, of 0.5 mg/kg NMBA for the first 5 weeks and then were treated with 0% (Group 1), 3.3% (Group 2), and 10% (Group 3) ethanol in the drinking water for up to 20 weeks. Group 4 received 10% ethanol without NMBA administration and Group 5 was maintained without any chemical treatment. There were no statistical differences in the incidence and multiplicity of esophageal tumors among Groups 1 to 3. However, the multiplicity of hyperplasias was statistically greater in Group 3 than in Groups 1 or 2. Esophageal epithelia of all rats in Groups 4 and 5 demonstrated a normal histology. BrdU labelling indices of tumors and hyperplasias in NMBA-treated groups were essentially similar, although cycline D1 was overexpressed to a greater extent in tumors and also hyperplasias of Group 3 than in Groups 1 or 2. The results indicated ethanol to exert weak promotion effects through cycline D1 overexpression on rat esophageal tumorigenesis initiated with NMBA.

Animals↗
PubMed2001

Isolation and structures of haterumadioxins A and B, cytotoxic endoperoxides from the Okinawan sponge Plakortis lita.

Cytotoxic endoperoxides, haterumadioxins A (1) and B (2), were isolated from the Okinawan sponge Plakortis lita. Their structures were determined by spectroscopic analysis. The absolute stereostructure of 1 was determined by degradation reactions and the modified Mosher's method. Haterumadioxins showed significant cytotoxicity against 38 human cancer cell lines.

Animals↗
PubMed2001

Hepatopulmonary syndrome associated with autoimmune liver cirrhosis.

A 46-year-old woman presented for evaluation of liver dysfunction and dyspnoea. Laboratory examination showed high levels of gamma-globulin, immunoglobulin (Ig)G, and antinuclear antibodies. Laparoscopy demonstrated hepatic cirrhosis. Despite normal spirometry, hypoxaemia (which was worse in standing position) and a low diffusing capacity were present. The shunt ratio calculated using arterial blood gas was 6.4%, but was 40% when measured using 99mTc-macroaggregated albumin scanning. The discrepancy between the ratios indicated that hypoxaemia was caused by intrapulmonary vascular dilatation. The patient was diagnosed with hepatopulmonary syndrome associated with autoimmune liver cirrhosis.

Female↗
PubMed2001

Comparison between 1-hour and 24-hour drain clamping using diluted epinephrine solution after total knee arthroplasty.

A prospective study was conducted to determine the optimal clamping time in the drain-clamping method after total knee arthroplasty. In a randomized trial, 44 primary total knee arthroplasties were studied after the drain-clamping method using diluted epinephrine solution was applied for 1 hour or 24 hours. The mean blood loss into the drains was less in the 24-hour group compared with the 1-hour group (35 mL in the 24-hour group and 247 mL in the 1-hour group). No statistically significant difference was found in hemoglobin or hematocrit levels between the 2 groups after surgery. Only 1 patient (4.5%) in the 1-hour group and 2 patients (9.1%) in the 24-hour group received blood transfusion. There were significantly more complications in the 24-hour group (P <.05). Two patients (9.1%) in this group required additional surgery. One-hour clamping is preferable to 24-hour clamping in the drain-clamping method for minimizing complications.

Aged↗
PubMed2001

Suppression of chemical carcinogenesis by water-soluble organosulfur compounds.

The chemopreventive effects of five water-soluble organosulfur compounds, S-methylcysteine (SMC) and four analogs, were examined on the promotion stage of diethylnitrosamine hepatocarcinogenesis in male F344 rats, using the medium-term bioassay (Ito test), which is based on the two-step model of hepatocarcinogenesis. In addition, we investigated the modifying effects of SMC and cysteine on the initiation stage of rat hepatocarcinogenesis. Carcinogenic potential was scored by comparing the numbers and areas of a putative neoplastic lesion, glutathione S-transferase placental form (GST-P)--positive hepatocellular foci. SMC and cysteine significantly decreased the number and area of GST-P--positive foci when given in the promotion stage of the Ito test. When given during the initiation stage, these two organosulfur compounds also significantly inhibited focus formation. Liver ornithine decarboxylase activity after two thirds partial hepatectomy and the proportion of hepatocytes positive for proliferating cell nuclear antigen significantly decreased the number of aberrant crypt foci in the colon in a multiorgan carcinogenesis bioassay of rats. These results support SMC and cysteine as chemopreventive agents for hepatocarcinogenesis and colon carcinogenesis. Their intake may be of importance for cancer.

Animals↗
PubMed2001

Borrelia sinica sp. nov., a lyme disease-related Borrelia species isolated in China.

A survey was performed for Lyme disease borrelia in the southern part of China, in Zhejiang, Sichuan and Anhui provinces, along the Yangtze River valley, in May of 1997 and 1998. Twenty isolates from Ixodes granulatus, Ixodes ovatus, Apodemus agrarius and Niviventer confucianus were obtained. These isolates were characterized by RFLP of the 5S-23S rDNA intergenic spacer, sequence analysis of the intergenic spacer, 16S rDNA and flagellin gene, DNA-DNA hybridization analysis, SDS-PAGE and Western blotting with mAbs. Six isolates from A. agrarius, five from I. granulatus collected in Zhejiang province and one from N. confucianus in Sichuan province were highly similar to strains 10MT and 5MT isolated in Korea and classified as Borrelia valaisiana. Four isolates from A. agrarius and I. granulatus collected in Zhejiang province generated unique RFLP patterns and phylogenetic analysis of the 16S rDNA and flagellin gene sequences suggested that the isolates should be classified as B. valaisiana. Furthermore, three isolates (CMN1a, CNM2, CMN3T) from N. confucianus captured in Sichuan province and one (CWO1) from I. ovatus in Anhui province showed lower 165 rDNA sequence similarity (less than 99.0%) to sequences of previously described Lyme disease-related Borrelia species. DNA-DNA hybridization results revealed that strains CMN3T and CMN1a were clearly distinct from all other known Lyme disease Borrelia species. Electron microscope observation showed the spirochaetes to be morphologically similar to those of Borrelia, but the cells contained only four periplasmic flagella inserted at each end of the spirochaetes. Based on these results, a new Borrelia species, Borrelia sinica sp. nov., is proposed. Strain CMN3T is the type strain of this new species.

Animals↗
PubMed2001

First records of tick-borne pathogens, Borrelia, and spotted fever group Rickettsiae in Okinawajima Island, Japan.

In early April 2000, tick-borne pathogens were surveyed in the northern area of Okinawajima Island, Okinawa Prefecture, which is the southernmost area of Japan. Borrelia valaisiana, a Lyme disease spirochete, was isolated from a field mouse Mus calori, and unidentified rickettsiae of the spotted fever group were isolated from all stages of Amblyomma testudinarium. These are the first reports of these pathogens on Okinawajima Island.

Animals↗
PubMed2001

Ultrastructural features of Borrelia garinii in naturally infected voles, Clethrionomys rufocanus, with special reference to the relationship with peripheral nerves.

The ultrastructural features of Borrelia garinii found in the ear tissues of the vole, Clethrionomys rufocanus, are described. The spirochetes were observed in the interstitium of connective tissue or in contact with fibroblasts and were occasionally situated in the endoneurium of the peripheral nerves. The spirochetes did not injure or enter into the fibroblasts or Schwann cells. The cytotoxicity and migration of the spirochetes are also discussed.

Animals↗
PubMed2001

[Murine typhus infected in Oku-etsu area, Fukui Prefecture].

A 15-year-old girl, high school student, became febrile (38-39 degrees C) with chills, sore throat and cough on April 20, 1994. Until the onset, she was healthy and she had been camping with her classmates in a wooded mountainous area in Oku-etsu, Fukui Prefecture. She consulted a local clinic on April 21 and bacampicillin was initially administered and then changed to cefaclor on April 23. However, high body temperature continued and a maclopapular rash appeared on her face on April 24 and gradually spread to her anterior chest and back. Blood examination showed a WBC count of 2,200/microliter, and she was admitted to our hospital on April 25. On admission, peripheral blood data showed leukocytopenia (WBC 2,300/microliter) with 5% atypical lymphocytes. Titers of anti-Rickettsia typhi serum antibodies (IgM, -G) were elevated (1:80, 1:640) and she was diagnosed as having murine typhus. On the second hospital day, 200 mg of minocycline (MINO) was administered per os and her body temperature fell to within the normal limits on the third hospital day. On the 7th hospital day, the skin rash disappeared and she was discharged. Altogether, 320 high school students went camping with this patient. Among them, approximately 30 students had similar symptoms and signs as this case and had been diagnosed suspected viral infection. Twelve students of the 30 were admitted to other hospitals. It was considered that this case was part of an outbreak of murine typhus in the Oku-etsu area, Fukui Prefecture, but no further investigation was performed. Murine typhus is usually a benign disease that is controllable by the administration of MINO. In rare cases, infection can worsen to multiorganic failure, severe complications have been reported in 1-4% of cases, and death has been reported in less than 3%. Recently, it has also been reported that MINO not only has an antibiotic effect, but also play acts as a cytokine modulator in patients with rickettsial infection. Thus, in febrile patients in whom uncommon Rickettsia infection is suspected, serological test for murine typhus should be examined and the immediate administration of MINO is important.

Adolescent↗
PubMed2001

[Epidemiological analysis on many cases of tsutsugamushi disease found in Hiroshima Prefecture, Japan].

The clinical findings of tsutsugamushi disease and the fauna of trombiculid mites in Hiroshima Prefecture were studied in this report. We reviewed 63 cases of tsutsugamushi disease occurring between 1990 and 1999, and most of cases were contracted in the area around the midportion of the Oota River (55 cases; 87.3%). Of these, 30 cases (47.1%) lived in Asakita-ku in Hiroshima City. Eschar was detected in 33/19 (84.6%) cases, and 97.6% (40/41), 88.9% (16/18) patients showed eruption and lymphadenopathy respectively. Biochemical examination revealed liver dysfunction in 38.1% (8/21) patients. Of the 11 cases examined on peripheral blood smear, atypical lymphocytes were detected in 10 cases (90.9%). Fifty-five cases (90.2%) occurred during the restricted season between September and December each year. The predominance of Leptotrombidium scutellare was verified by collection of trombiculid mites along the basin of the Oota River. Serum antibody titration on a patient in Asakita-ku showed reaction to Kawasaki type antigen definitive to L. scutellare. Therefore, we speculate that L. scutellare is a candidate for the vector of Orientia tsutsugamushi in Hiroshima Prefecture.

Adult↗
PubMed2001

Lyme disease Borrelia spp. in ticks and rodents from northwestern China.

In May 1999, field surveys of Lyme disease spirochetes were conducted around the Tianshan Mountains in Xinjiang Uygur Autonomous Region in northwestern People's Republic of China. Ixodes persulcatus ticks were obtained in a Tianchi Lake valley with primary forest, while the tick fauna was poor in the semidesert or at higher altitudes in this region. Species identities were confirmed by molecular analysis in which an internal transcribed spacer sequence was used. Of 55 adult ticks, 22 (40%) were positive for spirochetes as determined by Barbour-Stoenner-Kelly culture passages. In addition, some rodents, including Apodemus uralensis (5 of 14 animals) and Cricetulus longicaudatus (the only animal examined), and some immature stages of I. persulcatus (4 of 11 ticks) that had fed on A. uralensis were positive for spirochetes. Based on 5S-23S rRNA intergenic spacer restriction fragment length polymorphism analysis and reactivity with monoclonal antibodies, 35 cultures (including double isolation cultures) were identified as Borrelia garinii (20 isolates, including 9 Eurasian pattern B isolates and 11 Asian pattern C isolates), Borrelia afzelii (10 pattern D isolates), and mixed cultures (5 cultures, including isolates that produced B. garinii patterns B and C plus B. afzelii pattern D). These findings revealed that Lyme disease pathogens are distributed in the mountainous areas in northwestern China even though it is an arid region, and they also confirmed the specific relationship between I. persulcatus and genetic patterns of Borrelia spp. on the Asian continent.

Animals↗
PubMed2001

Fulminant Japanese spotted fever associated with hypercytokinemia.

We report a patient with Japanese spotted fever caused by Rickettsia japonica who developed shock associated with hypercytokinemia. Elevated levels of cytokines (macrophage colony-stimulating factor, interleukin 1 beta, interleukin 10, and gamma interferon) decreased rapidly after a combination treatment using an antibiotic (minocycline hydrochloride [MINO]) and methylprednisolone; however, tumor necrosis factor alpha levels were increased. The patient's fever relapsed and was resolved only after the addition of ciprofloxacin hydrochloride. The administration of new quinolones alone may be another useful form of treatment to eradicate R. japonica even if the symptoms of hypercytokinemia appear to improve with the administration of MINO and methylprednisolone.

Aged↗
PubMed2001

Gene expression profiles in Ciona intestinalis tailbud embryos.

A set of 3423 expressed sequence tags derived from the Ciona intestinalis tailbud embryos was categorized into 1213 independent clusters. When compared with DNA Data Bank of Japan database, 502 clusters of them showed significant matches to reported proteins with distinct function, whereas 184 lacked sufficient information to be categorized (including reported proteins with undefined function) and 527 had no significant similarities to known proteins. Sequence similarity analyses of the 502 clusters in relation to the biosynthetic function, as well as the structure of the message population at this stage, demonstrated that 390 of them were associated with functions that many kinds of cells use, 85 with cell-cell communication and 27 with transcription factors and other gene regulatory proteins. All of the 1213 clusters were subjected to whole-mount in situ hybridization to analyze the gene expression profiles at this stage. A total of 387 clusters showed expression specific to a certain tissue or organ; 149 showed epidermis-specific expression; 34 were specific to the nervous system; 29 to endoderm; 112 to mesenchyme; 32 to notochord; and 31 to muscle. Many genes were also specifically expressed in multiple tissues. The study also highlighted characteristic gene expression profiles dependent on the tissues. In addition, several genes showed intriguing expression patterns that have not been reported previously; for example, four genes were expressed specifically in the nerve cord cells and one gene was expressed only in the posterior part of muscle cells. This study provides molecular markers for each of the tissues and/or organs that constitutes the Ciona tailbud embryo. The sequence information will also be used for further genome scientific approach to explore molecular mechanisms involved in the formation of one of the most primitive chordate body plans.

Animals↗
PubMed2001

Changes in Ca2+ signaling and contractile protein isoforms in smooth muscle cells from guinea pig ileum during culture.

Single smooth muscle cells (SMCs) isolated from guinea pig ileum using collagenase and papain were cultured on laminin-coated dishes in MEM containing fetal calf serum. Temporal changes in intracellular calcium ion concentration in response to carbachol and to ATP were investigated using fluo-3/AM and fluorescence microscopy. It was observed that carbachol caused an increased intracellular calcium ion in freshly isolated single SMCs but a reduced or negative response of cultured SMCs before confluence. On the other hand, ATP was observed to cause an increase in the calcium ion content of SMCs throughout the culture. SDS-PAGE and Western blot analyses revealed changes in the expression of contractile proteins as follows. l-Caldesmon and non-muscle type myosin heavy chain (NMHC) (considered to be marker molecules for dedifferentiation in smooth muscle cells) and non-muscle type tropomyosin were not observed in freshly isolated single SMCs. l-Caldesmon and NMHC appeared in the cultured SMCs within 2 days and the tropomyosin isoform was observed 6 days following seeding. Simultaneously, smooth muscle type myosin heavy chain (SMHC) decreased strikingly and the 41 kDa tropomyosin monomer was lost. The content of alpha-actin decreased gradually to a minimum on day 6 when non-muscle type tropomyosin appeared, and the cells began to proliferate rapidly. These results suggest that the loss of contractility in cultured smooth muscle cells is more closely related to changes in contractile protein profiles than to receptor-mediated signal transduction and that in addition to NMHC and l-caldesmon, non-muscle type tropomyosin may be useful as a marker molecule for de-differentiation of smooth muscle cells.

Actins↗
PubMed2001

Detection of p53 gene mutations in human esophageal squamous cell carcinomas using a p53 yeast functional assay: possible difference in esophageal carcinogenesis between the young and the elderly group.

A p53 yeast functional assay, which cannot only detect p53 gene mutations but also can assess p53 gene function, was used to screen for p53 gene dysfunction in human esophageal squamous cell carcinomas. Surgically resected frozen tissues of esophageal squamous cell carcinomas from 57 patients were examined for p53 gene mutation. Because the mean age of the patients diagnosed with esophageal squamous cell carcinoma was 64 years, we classified those who were <65 years of age as the Young Group and classified the others as the Elderly Group. The incidence of p53 gene mutations was 43 of 57 (75%). The incidence of p53 gene mutations observed in the Young Group was significantly higher than in the Elderly Group (P = 0.0007). Alcohol and smoking status did not relate to p53 gene mutation expression. Survival rate after surgery was not significantly associated with the presence of p53 gene mutation. However, in the Young Group with p53 gene mutation, those who had null mutations had a significantly shorter survival than those without null mutations (P = 0.0455). No other clinicopathological factors were associated with p53 gene mutations. Possibly, there may be a difference in esophageal carcinogenesis between the Young and the Elderly groups, because the incidence of p53 gene mutations is different between the two groups. In the Young Group, p53 gene mutation may cause esophageal carcinogenesis, and null mutation for p53 gene is a significant prognostic factor.

Age Factors↗
PubMed2001

Bilirubin as a tracer for detecting gastroesophageal reflux.

PURPOSE: The usefulness of intraesophageal monitoring of bilirubin, in diagnosing gastroesophageal reflux, was studied. PATIENTS AND METHODS: Bilirubin concentration and pH at 5 cm oral and anal to the esophagogastric junction were monitored for 24 hours in 19 patients with reflux esophagitis. The duration of bilirubin presented and pH less than 4.0 were obtained as the holding time (HT) of bilirubin and acid, respectively. RESULTS: There was no difference between HT of bilirubin and acid in the stomach and esophagus. In the stomach, HT of bilirubin did not correlate with acid. Whereas, in both of bilirubin and acid, HT in the esophagus correlated significantly with that in the stomach. The correlation was more definite for bilirubin than acid. CONCLUSIONS: Bilirubin and acid presented in the upper stomach for sufficient period independently. Bilirubin monitoring was useful to evaluate the etiology of damaging the esophageal mucosa and causes of symptoms by estimating duodenogastro-esophageal reflux, which has synergistic effect with acid.

Adult↗