Biomedical subjects

H Watanabe

Publications and source records attributed to H Watanabe.

At least 631 records · Page 35Linked to original sources

PubMed1999

Diagnostic value of endoscopic retrograde pancreatography in chronic pancreatitis based on the new criteria proposed by the Japan Pancreas Society in 1995: comparison with the criteria proposed by the Japanese Society of Gastroenterology in 1983.

This study evaluated the new criteria for the diagnosis of chronic pancreatitis (CP) with endoscopic retrograde pancreatography (ERP) proposed by the Japan Pancreas Society in 1995 by comparing it with the older criteria of the Japanese Society of Gastroenterology proposed in 1983. No significant differences were noted between the two when the diagnostic sensitivity of ERP was considered in calcifying CP. Among 54 patients of noncalcifying CP (group I) with ERP diagnosis of moderate or advanced pancreatitis by the previous criteria, only one of 22 with the localized type was definite CP. The remaining 21 were ruled out as either definite or probable CP, and six were classified as having chronic obstructive pancreatitis based on the new criteria. In contrast, a diagnosis of definite CP was made not only for all the 32 patients with CP (group I) of diffuse type but also in 11 cases of CP (group II) with diffuse minimal pancreatitis showing irregular dilatation of the side branches with scattered distribution throughout the gland. In a series of 15 follow-up patients with CP (group II) having initial ERP diagnosis of minimal pancreatitis, CP group I developed in three of five cases of diffuse minimal pancreatitis, which is consistent with definite CP by the new criteria, whereas progression to this group of CP was found in none of the 10 patients with localized minimal pancreatitis. These results indicate that although localized CP is excluded from CP, the incidence of diffuse noncalcifying CP diagnosed by ERCP was increased with the new criteria, and detecting radiologic features with diffuse irregular dilatation of the branch ducts based on these criteria may lead to early diagnosis of CP.

Calcinosis↗

PubMed1999

Prolonged incubation period of salmonellosis in an outbreak of Salmonella enteritidis infection.

An outbreak of Salmonella enteritidis infections occurred in Otaru, Japan, in September 1997. A total of 143 cases of salmonellosis were reported to the local Public Health Center. In this outbreak, one case had a 214-hr incubation period. We investigated 5 isolates including this case by phage typing and pulsed-field gel electrophoresis (PFGE) to determine the genetic heterogeneity of S. enteritidis. Five isolates were phage typed as reacted, but did not conform (RDNC) with identical reaction patterns and had quite similar PFGE patterns. Thus, the prolonged incubation period may not be attributed to genetic heterogeneity of the organism but rather to other factors.

Adult↗

PubMed1999

Evaluation of AFLP, a high-resolution DNA fingerprinting method, as a tool for molecular subtyping of enterohemorrhagic Escherichia coli O157:H7 isolates.

The amplified fragment-length polymorphism (AFLPTM) technique is based on the selective PCR amplification of restriction fragments. We investigated the utility of AFLP in the molecular subtyping of enterohemorrhagic Escherichia coli serotype O157:H7 isolates. We analyzed a total of 46 isolates of E. coli O157:H7 along with other serotypes, O26:H11, 0114:H19 and 0119:NT. Isolates of E. coli O157:H7 derived from the same outbreak showed an identical AFLP-banding pattern and were subtyped into the same group, giving results almost consistent with those of a pulsed-field gel electrophoresis (PFGE) study, while other serotypes showed clearly different patterns from those of E. coli O157:H7. These results suggest that the AFLP technique has potential as an alternative tool for the molecular epidemiology of E. coli O157:H7.

Bacterial Typing Techniques↗

PubMed1999

Analysis of the c-myc, K-ras and p53 genes in methylcholanthrene-induced mouse sarcomas.

We have examined 63 methylcholanthrene (MCA)-induced mouse sarcomas for possible correlations of mutations involving the c-myc, ras and p53 genes. The c-myc gene was found to be amplified in 18 of these sarcomas (29%). Polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis and subsequent direct sequencing identified 18 cases carrying K-ras mutation at codons 12, 13 and 61 (29%). No mutation was detected in the H-ras and N-ras genes. Mutations of the p53 gene in exons 5 to 8 were found in 45 cases (71%). Comparison of these mutations revealed that out of 18 cases with c-myc gene amplifications, 10 carried K-ras mutations (56%) and 14 carried p53 mutations (78%). In contrast, among 45 cases of sarcomas without c-myc gene amplification, 8 were found to have K-ras mutations (18%). The same 45 cases were found to have 31 p53 mutations (69%). The present study suggests a strong correlation between c-myc gene amplification and K-ras gene mutation (P < 0.01). p53 gene mutation was frequently found among MCA-induced mouse sarcomas, indicating the importance of this mutation in the etiology of these tumors. However, p53 mutations were present in sarcomas regardless of the state of c-myc amplification and K-ras mutation. Therefore, a defect in the p53 gene is independent of amplification of the c-myc gene or point mutation of the K-ras gene.

Animals↗

PubMed1999

Gastric tumor induction by 1,2-dimethylhydrazine in Wistar rats with intestinal metaplasia caused by X-irradiation.

Five-week-old male Wistar rats were X-irradiated with a total of 20 Gy in 2 equal fractions at a 3-day interval. 1,2-Dimethylhydrazine (DMH) solution was injected i.m. into the back musculature at a dose of 20 mg/kg body weight weekly for 10 weeks, beginning 20 weeks after the final irradiation. Twelve months after the initial carcinogen treatment, tumors in the fundus of the glandular stomach were observed in 5 of 23 animals receiving both X-irradiation and DMH treatment. No tumors of the glandular stomach were observed in the DMH and X-ray alone or nontreatment groups. It is concluded that the presence of intestinal metaplasia may increase sensitivity to the induction of gastric tumors by carcinogens like DMH.

1,2-Dimethylhydrazine↗

PubMed1999

Multiple K-ras mutations in hyperplasia and carcinoma in cases of human pancreatic carcinoma.

Mucous cell hyperplasia (MCH) has been considered an important precursor of pancreatic ductal carcinoma based on histological and molecular research, although various K-ras mutations rates are seen among cases with pancreatic carcinoma, chronic pancreatitis and normal pancreas, with a wide range of histological characters. To investigate the premalignant potential of MCH and the multicentricity of pancreatic carcinoma, we analyzed K-ras mutation at codon 12 in carcinoma foci of 82 cases of surgically-resected pancreatic carcinoma [67 solid-type carcinomas (SCs) and 15 ductectatic-type carcinomas (DCs)], as well as in both MCH and carcinoma foci in 42 cases (30 SCs and 12 DCs), using an enriched polymerase chain reaction (PCR)-enzyme linked mini-sequence assay (ELMA). K-ras mutation was recognized in 85% (57/67) of SCs and 73% (11/15) of DCs, and multiple K-ras mutations in 12% (8/67) of SCs and in 20% (3/15) of DCs. Multiple K-ras mutations were also recognized in MCHs in 47% (14/30) of SCs and in 42% (5/12) of DCs. Moreover, the same sequence at K-ras codon 12 in MCH and carcinoma was identified in 76% (32/42) of carcinoma cases and it was more frequently recognized in hyperplasias with histological atypia (51%, 37 of 72 foci) than those without atypia (24%, 16 of 68 foci) (P<0.0007). These results further support the idea of multicentric carcinogenesis and premalignant potential of atypical hyperplasia in the human pancreas, although about half of the hyperplasias around carcinomas were not thought to be direct precursors.

Adult↗

PubMed1999

Brain natriuretic peptide (BNP) and cyclic guanosine monophosphate (cGMP) levels in normal pregnancy and preeclampsia.

OBJECTIVE: Our purpose was to evaluate plasma levels of brain natriuretic peptide (pBNP) and cyclic guanosine monophosphate (pcGMP) in preeclamptic patients and controls. STUDY DESIGN: Blood samples were obtained from 35 patients with preeclampsia and from the same women during the subsequent puerperal period. The control group consisted of normotensive pregnant women, matched with the patients for age, gestational age, and parity. The concentrations of pBNP and pcGMP were determined by the RIA method. Statistical analysis was performed using the Mann-Whitney's U test. RESULTS: The pBNP level in the preeclampsia group was significantly increased, to 7-fold that of the control group. The pcGMP level was 50% higher in the preeclampsia group than in the control group, but this was not significant. Both the pBNP level and the pcGMP level in the puerperal period did not significantly differ between the patients and the controls. CONCLUSION: The pBNP concentrations increased in the preeclamptic women, and then these compensations were normalized in the puerperal period.

Adult↗

PubMed1999

Spontaneous splenic rupture in a patient with large hepatocellular carcinoma.

We report a 61-yr-old woman with acute circulatory failure from spontaneous splenic rupture with decompensated liver cirrhosis complicating large hepatocellular carcinoma exposed on the right liver surface. On admission, the patient was tentatively diagnosed as having rupture of the hepatocellular carcinoma, and she died 15 hours after admission despite blood transfusion. Autopsy revealed that the origin of the intraperitoneal hemorrhage was a ruptured spleen. According to a MEDLINE search of the English-language literature published between 1966 and March 1998, this is the first reported case of spontaneous splenic rupture in a patient with hepatocellular carcinoma without splenic metastasis.

Carcinoma, Hepatocellular↗

PubMed1999

Carcinosarcoma of the ampulla of Vater: a case report with immunohistochemical and ultrastructural studies.

Carcinosarcoma of the duodenum has not been reported previously, although this type of tumor has been detected in other organs. We present here a case of carcinosarcoma of the duodenum, including immunohistochemical and electron microscopical findings. An ulcerating tumor, located in the duodenal ampullary region, contained two divergent components: ordinary differentiated tubular adenocarcinoma, and sarcomatoid tissue composed of spindle tumor cells. Immunohistochemically, the adenocarcinoma cells were stained with antibodies against epithelial markers including keratin and CA19-9. In contrast, the sarcomatoid tissue was strongly positive for vimentin and was focally positive for myoglobin, keratin, and CA19-9. We speculate that the sarcomatoid element of the carcinosarcoma arose from part of the ordinary adenocarcinoma tissue.

Ampulla of Vater↗

PubMed1999

Erythropoietin induces the expansion of c-kit+ progenitors for myeloid and erythroid cells, but not for lymphoid cells, in the bone marrow and liver.

In humans, the numbers of erythrocytes and granulocytes, but not that of lymphocytes, tend to increase in parallel. To determine the mechanism, we investigated how the administration of erythropoietin induces the expansion of erythroid cells and other lineage cells in the bone marrow, liver, and other organs of mice. When mice were injected twice (days 1 and 2) with erythropoietin at a dose of 20 or 200 IU/day/ mouse, a prominent expansion of TER 19+ (erythroid cells) and Gr-1high cells (granulocytes) occurred in the liver, spleen, and bone marrow day 3 after the initial injection. On the other hand, lymphoid cells, including NK cells, extrathymic T cells, and conventional T cells, did not expand. In parallel with the expansion of erythroid cells and granulocytes, the levels of c-kit(+)Lin- cells increased in the liver and bone marrow. Despite the increase in the proportion of c-kit(+) Lin(-) cells, the generation of lymphocytes (e.g., T cells) decreased when such bone marrow cells were injected to scid mice. These results suggest that erythropoietin has the ability to induce the expansion of not only erythroid cells but also granulocytes in the liver, spleen, and bone marrow. Furthermore, c-kit+ progenitors which may commit themselves to erythroid and myeloid cells, but not to lymphoid cells, were also activated in the liver and bone marrow of mice treated with erythropoietin.

Adult↗

PubMed1999

Post-operative symptoms and healing after endodontic treatment of infected teeth using pulsed Nd:YAG laser.

Forty-four teeth in 38 patients, diagnosed with chronic apical periodontitis, were endodontically treated. Root canals were shaped using a step-back technique with 5% NaOCl and 3% H2O2 as irrigants. In half of the teeth the canal terminus was irradiated with pulsed Nd:YAG laser (1 W, 15 pps, 1 s). All canals were then obturated with laterally condensed gutta-percha points and sealer, and final radiographs were obtained. Occurrence of spontaneous pain was recorded 1 day after treatment. Percussion pain was recorded after 1 week, and then at 3 and 6 months after treatment. Radiographic follow-up was performed at 3 and 6 months. Percussion pain was significantly less (P < 0.05) in the laser-treated group than in the control group, both 1 week and 3 months after treatment. Other differences between the groups were not significant. These results suggested that the clinical application of pulsed Nd:YAG laser might be advantageous for the treatment of infected root canals.

Adult↗

PubMed1999

[Drug-resistance and definitive type 104 of Salmonella serovar typhimurium isolated from sporadic cases in Tokyo, 1980-1998].

A total of 674 Salmonella serovar Typhimurium (S. Typhimurium) strains consisting of 522 domestic strains and 152 imported strains isolated in Tokyo, 1980-1998, were examined regarding their drug-resistance and phage-type. Domestic strains accounted for 6.2% of all Salmonella (8,359 strains) isolated from domestic cases, and imported strains accounted for 3.7% of all Salmonella (4,083 strains) isolated from imported cases. A drug-resistance test using 9 drugs (CP, TC, SM, KM, ABPC, ST, NA, FOM, and NFLX) showed that 245 strains (46.9%) of the domestic strains and 109 strains (71.7%) of the imported strains were resistant to some of the drugs, excluding FOM and NFLX. Drugs with a high resistance rate were TC, SM, ABPC, and CP for both groups. Drug-resistance patterns of the resistant strains varied among the 40 types. Among those, prevalent patterns recognized were CP.TC.SM.ABPC, CP.TC.SM.KM.ABPC, TC.SM, SM, and TC.KM in the domestic strains, and TC, CP.TC.SM.ABPC, CP.TC.SM.KM.ABPC, CP.TC.SM.KM.ABPC.ST and TC.KM in the imported strains. The results of the phage-typing test revealed that 31 strains of 52 domestic strains tested, and 13 strains of 46 imported strains tested were definitive type 104 (DT104). Those resistance patterns were CP.TC.SM.ABPC.SU (43 strains) and CP.TC.SM.KM.ABPC.SU (1 strain).

Anti-Bacterial Agents↗

PubMed1999

[Microbiological and clinical studies with Streptococcus pneumoniae isolated in 5 Kitakyushu municipal hospitals].

Epidemiological and microbiological studies were carried out using 200 strains of pneumococci isolated from clinical specimens in 5 Kitakyushu municipal hospitals, between October 1994 and July 1995. Eighty nine percent of pneumococci were detected in the specimens from the respiratory tract. Pneumococci were isolated mainly from infants under 3-years of age and adults over 50-years of age, and the rates of isolation were 40.5% and 39.5%, respectively. MICs of 8 antimicrobial agents, such as PCG, NFLX, CPFX, LFLX, FLRX, TFLX, SPFX, LVFX, were determined using broth microdilution methods. According to NCCLS standard (1997), recovery rates of PSSP, PISP and PRSP were 48.0%, 39.5% and 12.5%, respectively. Among 7 quinolones, TFLX, SPFX and LVFX were effective so far examined, except for a few resistant strains. Four cases in which quinolones resistant pneumococci were isolated were reviewed retrospectively. Among them 3 cases had been given quinolones before the strains were detected.

Adolescent↗

PubMed1999

[Isolation of Shiga toxin-producing Escherichia coli O157:H7 from processed salmon roe associated with the outbreaks in Japan, 1998, and a molecular typing of the isolates by pulsed-field gel electrophoresis].

Shiga toxin-producing Escherichia coil (STEC) O157 were isolated from processed salmon roe which had been a suspected food item in sporadic infections which occurred in Japan in 1998. A total of 45 samples of the processed salmon roe were pre-enriched in trypticase soy broth (TSB) at 36 degrees C for 6 h and novobiocin-supplemented modified EC broth (mEC-NB) at 42 degrees C for 18 h. After the pre-enrichments, the cultures were examined for possible occurrence of STEC O157, using an immunomagnetic separation (IMS) method. From the examination, a total of 84 strains of STEC O157:H7 that were positive for both stx 1 and stx 2 genes were isolated. By applying the most-probable-number technique, it was estimated that the number of STEC O157 was in the range of 0.73-1.5 per 10 g of the processed salmon roe. Subsequent analysis of the isolates by a pulsed-field gel electrophoresis (PFGE) revealed a pattern commonly seen in 82 isolates and another pattern in two isolates. Clinical isolates from 7 patients also showed an identical pattern to those of the 82 isolates and one isolate from a patient showed the other pattern identical to those of the two isolates. The isolates were found to belong to the phage type 14.

DNA, Bacterial↗

PubMed1999

Stress tolerance in doughs of Saccharomyces cerevisiae trehalase mutants derived from commercial Baker's yeast.

Accumulation of trehalose is widely believed to be a critical determinant in improving the stress tolerance of the yeast Saccharomyces cerevisiae, which is commonly used in commercial bread dough. To retain the accumulation of trehalose in yeast cells, we constructed, for the first time, diploid homozygous neutral trehalase mutants (Deltanth1), acid trehalase mutants (Deltaath1), and double mutants (Deltanth1 ath1) by using commercial baker's yeast strains as the parent strains and the gene disruption method. During fermentation in a liquid fermentation medium, degradation of intracellular trehalose was inhibited with all of the trehalase mutants. The gassing power of frozen doughs made with these mutants was greater than the gassing power of doughs made with the parent strains. The Deltanth1 and Deltaath1 strains also exhibited higher levels of tolerance of dry conditions than the parent strains exhibited; however, the Deltanth1 ath1 strain exhibited lower tolerance of dry conditions than the parent strain exhibited. The improved freeze tolerance exhibited by all of the trehalase mutants may make these strains useful in frozen dough.

Carbon Dioxide↗

PubMed1999

Nuclear transport of the major capsid protein is essential for adeno-associated virus capsid formation.

Adeno-associated virus capsids are composed of three proteins, VP1, VP2, and VP3. Although VP1 is necessary for viral infection, it is not essential for capsid formation. The other capsid proteins, VP2 and VP3, are sufficient for capsid formation, but the functional roles of each protein are still not well understood. By analyzing a series of deletion mutants of VP2, we identified a region necessary for nuclear transfer of VP2 and found that the efficiency of nuclear localization of the capsid proteins and the efficiency of virus-like particle (VLP) formation correlated well. To confirm the importance of the nuclear localization of the capsid proteins, we fused the nuclear localization signal of simian virus 40 large T antigen to VP3 protein. We show that this fusion protein could form VLP, indicating that the VP2-specific region located on the N-terminal side of the protein is not structurally required. This finding suggests that VP3 has sufficient information for VLP formation and that VP2 is necessary only for nuclear transfer of the capsid proteins.

Amino Acid Sequence↗

PubMed1999

DNA microsatellite instability in hyperplastic polyps, serrated adenomas, and mixed polyps: a mild mutator pathway for colorectal cancer?

AIM: To investigate the distribution of DNA microsatellite instability (MSI) in a series of hyperplastic polyps, serrated adenomas, and mixed polyps of the colorectum. METHODS: DNA was extracted from samples of 73 colorectal polyps comprising tubular adenomas (23), hyperplastic polyps (21), serrated adenomas (17), and mixed polyps (12). The presence of MSI was investigated at six loci: MYCL, D2S123, F13B, BAT-40, BAT-26, and c-myb T22, using polymerase chain reaction based methodology. MSI cases were classified as MSI-Low (MSI-L) and MSI-High (MSI-H), based on the number of affected loci. RESULTS: The frequency of MSI increased in tubular adenomas (13%), hyperplastic polyps (29%), serrated adenomas (53%), and mixed polyps (83%) (Wilcoxon rank sum statistic, p < 0.001). Hyperplastic epithelium was present in nine of 12 mixed polyps and showed MSI in eight of these. MSI was mostly MSI-L. MSI-H occurred in two serrated adenomas and three mixed polyps. Clonal relations were demonstrated between hyperplastic and dysplastic epithelium in four of eight informative mixed polyps. CONCLUSIONS: The findings support the view that hyperplastic polyps may be fundamentally neoplastic rather than hyperplastic. A proportion of hyperplastic polyps may serve as a precursor of a subset (10%) of colorectal cancers showing the MSI-L phenotype, albeit through the intermediate step of serrated dysplasia. This represents a novel and distinct morphogenetic pathway for colorectal cancer.

Adenoma↗

PubMed1999

Axonal and perikaryal involvement in chronic inflammatory demyelinating polyneuropathy.

OBJECTIVES: To assess the extent of loss of myelinated nerve fibres and spinal motor neuron loss in chronic inflammatory demyelinating polyneuropathy (CIDP), a clinicopathological study was conducted on biopsied sural nerves and necropsied spinal cords from patients with CIDP. METHODS: The myelinated fibre pathology of 71 biopsied sural nerves and motor neuron pathology of nine necropsied spinal cords at L4 levels in patients with CIDP were quantitatively and immunohistochemically assessed. RESULTS: Myelinated nerve fibre density was significantly diminished to 65.4% of the control values (p <0.0001), correlating inversely with the extent of segmental demyelination and remyelination (r = -0.43, p < 0.0005) and duration of illness (r = -0.31, p < 0.01). Numbers of large spinal motor neurons in CIDP were variably but significantly diminished (range from 46.0 to 97.6% of the age matched control value (p < 0.005)), and reactive astrogliosis was evident in the ventral horn in CIDP. The frequency of ventral horn neurons exhibiting central chromatolysis and the accumulation of phosphorylated high molecular weight neurofilament protein was significantly higher in CIDP than in controls (p<0.01 and p<0.05). CONCLUSIONS: The loss of nerve axons and spinal motor neurons is common in CIDP, and extensive in some cases. These neuronal and axonal losses may influence the functional prognosis in CIDP.

Adolescent↗