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Biomedical subjects

H Watanabe

Publications and source records attributed to H Watanabe.

At least 811 records · Page 45Linked to original sources

Combined use of bacteriophage typing and pulsed-field gel electrophoresis in the epidemiological analysis of Japanese isolates of enterohemorrhagic Escherichia coli O157:H7.

A total of 236 enterohemorrhagic Escherichia coli (EHEC) O157:H7 isolates in Japan were investigated by bacteriophage typing, and the results were compared with those of pulsed-field gel electrophoresis (PFGE). Seven phage types (PTs) were observed in 71 isolates which were derived from 22 outbreaks. All of the isolates from ten outbreaks in the Kinki region (midwestern part of Japan) in July-August 1996 were grouped into the same PFGE type (IIa) and PT 32, while among total isolates, there were such varieties as PFGE type IIa containing five phage types and PT32 containing two PFGE types. These results suggest that the ten outbreaks should be considered to be a single outbreak, and show that the combined use of bacteriophage typing and PFGE enhances reliability in epidemiological surveys.

Bacteremia↗

Alteration of p53 clonality accompanying colorectal cancer progression.

The aim of this study was to clarify whether or not the status of gene alteration is heterogeneous in intramucosal carcinoma and homogeneous within invasive carcinoma. We selected 10 colorectal carcinoma cases (1 mucosal, 5 submucosal and 4 advanced carcinomas including 2 cases with lymph node metastasis) and analyzed the p53 gene sequence. Six colorectal cancers in this study showed heterogeneity in p53 mutations in cells from the intramucosal part. In the invasive part of a carcinoma, p53 mutation status was homogeneous intratumorally in all cases. These data indicate that, in regard to p53 gene alterations, colorectal cancers can be composed of various subclones when limited to the mucosa, but clonal selection occurs when one of these subclones commences invasion to the submucosa, generating a monoclonal invasive carcinoma.

Adenoma↗

p53 gene mutation and loss of heterozygosity of chromosome 11 in methylcholanthrene-induced mouse sarcomas.

Mutations of the p53 tumor suppressor gene are the most prevalent genetic alteration observed in a wide variety of human cancers. In this study we examined 63 methylcholanthrene (MCA)-induced sarcomas from C57BL/6N x C3H/HeN F1 (BCF1) or C3H/HeN x C57BL/6N F1 (CBF1) mice for p53 gene mutations and loss of heterozygosity (LOH) of chromosome 11. Mutation analysis was done on exons 5 to 8 of the p53 gene by polymerase chain reaction-single strand conformation polymorphism analysis. This identified 53 potential mutations in 45 sarcomas. Mutations were further confirmed by direct sequencing of the region. Forty-nine of the 53 cases (94%) were missense mutations, while the rest included two nonsense mutations, one silent mutation and one insertional mutation. Spectra of base substitutions were: 25 cases (47%) of G:C-->T:A transversion, 13 cases (25%) of G:C-->A:T transition (CpG site 15%), 13 cases (24%) of G:C-->C:G transversion, a case (2%) of A:T-->T:A transversion and a case (2%) of insertion. In addition, analysis of 5 polymorphic markers of mouse chromosome 11 revealed LOH in ten cases (22%) among those carrying p53 mutations. In nine of these 10 cases, the loss involved all 5 markers. In addition, the loss was biased toward the C57BL allele (9 cases). The present study establishes the pattern of mutation of the p53 gene in MCA-induced mouse sarcomas.

Amino Acid Sequence↗

Heterogeneity of p53 mutational status in esophageal squamous cell carcinoma.

In esophageal squamous cell carcinoma, p53 gene mutations have been analyzed for inter- or intra-patient heterogeneity but only a few studies have investigated intratumoral heterogeneity. We investigated this question within individual esophageal cancers, and also in their lymph-node metastases in 8 cases. Analyzing the p53 gene sequence by direct sequencing of polymerase chain reaction products, we found heterogeneity for p53 mutations in the pre-invasive area in 3 esophageal cancers. In all areas sampled in the invasive portion of each cancer, the p53 mutational status was identical in a given tumor. In heterogeneous tumors, the invasive area showed one of the p53 mutations found in the pre-invasive area. In nodal metastases, the p53 mutation was identical to that in the invasive area of each primary tumor. These data suggest that the timing of p53 alteration is not as early as might have been expected, indicating that, in regard to p53 gene alteration, some esophageal cancers are composed of various subclones in the pre-invasive stage with invasiveness developing in one of them, which becomes predominant through clonal selection.

Aged↗

Usefulness of the [13C]-urea breath test for detection of Helicobacter pylori infection in fasting patients.

Most of the reported [13C]-urea breath test procedures use a test meal, which is believed to assist in the spread of the [13C]-urea solution into the entire stomach, as results without a test meal may mainly reflect urease activity in the antrum.Yet, procedures for the [13C]-urea breath test and interpretation of the obtained 13C excess value have not been well established. We carried out the present study to validate the usefulness of the [13C]-urea breath test in fasting subjects and to establish cut-off values. [13C]-Urea breath tests were performed on 258 Helicobacter pylori-positive and 151 -negative subjects (247 H. pylori positive and 26 negative prior to any H. pylori cure treatment and 125 H. pylori negative and 11 positive after undergoing H. pylori cure treatment). The breath test procedure was performed under the following conditions: an 8 h fast, mouth washing before and after dosing, administration of 100 mg [13C]-urea, collection of breath sample in a plastic bag, a baseline and a 20 min sampling point and subject in a sitting position. Delta-13C at the 20 min sampling point in H. pylori-positive and -negative subjects was 31.0+/-1.25 and 1.6+/-0.11%, respectively. Although the mean delta13C value was greatest in duodenal ulcer or ulcer scar patients, there were no significant differences among mean delta13C values in the various diseases. From Receiver Operator Characteristic curves and calculation of accuracy of the test, a cut-off value of 5.0% is considered to be appropriate for diagnosis of H. pylori infection, which provides 96.7% specificity and 96.5% sensitivity, suggesting that the [13C]-urea breath test in the fasting state is as effective in detecting the presence of H. pylori as other reported methods.

Adult↗

Case report: a patient who developed an amoebic liver abscess during treatment with interferon.

A 65-year-old female received recombinant interferon (IFN) alpha-2b daily for the treatment of chronic hepatitis C. Fever (39 degrees C or higher) developed 14 days after the start of administration. Abdominal computed tomography suggested multiple liver abscesses, which had not been detected before IFN administration. An autopsy revealed an amoebic liver abscess. A subclinical infection of Entamoeba histolytica in this case developed into amoebic liver abscess during IFN administration.

Aged↗

How does the distention of urinary bladder cause arousal?

Under urethane anesthesia, the urinary bladder of male rats was distended by 0.3-0.5 mL of saline. When the animals displayed large amplitude delta waves, the distention caused tonic excitation in 76% (19/25) of the noradrenergic neurons in the locus coeruleus and in 53% (16/30) of the cholinergic neurons in the laterodorsaltegmental nucleus. The response was followed by a shift of electroencephalogram (EEG) pattern to faster waves of smaller amplitude. When EEG amplitude was faster and smaller, the same stimuli caused no response. Neurons in Barrington's nucleus were excited by a small amount of bladder distention independent of EEG patterns. These results suggest that the transition of state, caused by bladder distention, from deep sleep to light sleep is mediated by noradrenergic and cholinergic neurons in the brainstem.

Adrenergic Fibers↗

Relationship between nocturnal urinary frequency and sleep disturbances in aged men.

The relationship between nocturnal urinary frequency and sleep disturbances is investigated in aged men in 12 rural towns in Kyoto and Shiga Prefectures. The subjects were 178 men who did not have diseases or symptoms that were likely to affect urinary condition or sleep. There were no significant differences in sleep disturbances, except sleep maintenance, between the normal group (nocturnal urinary frequency below twice per night) and the abnormal group (nocturnal urinary frequency twice or more per night). In healthy aged men, nocturnal urinary frequency only caused disturbance in sleep maintenance, but did not cause any other sleep disturbance.

Age Factors↗

Child psychiatry training for pediatricians: Japanese perspectives in infant psychiatry.

Since August 1993, child psychiatry training by a full-time child psychiatrist has become an essential component of the postgraduate training programme at the Department of Paediatrics, Keio University Hospital, Japan. Thirty trainees, 15 first-years and 15 second-years, had first-hand experience in residential child psychiatric treatment concurrently with pediatric training. With the trainees as primary care workers, 31 cases have been successfully treated, of whom seven were school refusals, 11 were anorexia nervosas and eight somatoform disorders. Consistent maternal care, such as three spoon-feeding sessions each day, were prescribed for anorexic patients, which enhanced sensitivity in the trainees to the unmet infantile needs of their patients and facilitated awareness of their chronic unhappiness since early life and to the therapeutic implications of empathic understanding based on trustful relationships. After the 2 years of training the first group of trainees showed competency in handling children's emotional problems on their own in distant affiliated hospitals. The flexible multidisciplinary style of training that has evolved over the past 2 years has proved to have enormous relevance in the changing contexts of the pediatric practice in Japan.

Adolescent↗

Nonfunctioning adrenal cortical cancer and analysis of the steroidogenic activity of the tumor: a case report.

An adrenocortical cancer was detected by a CT scan in a 37-year-old woman, which did not have an excessive secretion of steroids or catecholamines. The tumor was enhanced inhomogeneously by the bolus injection of contrast medium, and magnetic resonance imaging (MRI) showed that the tumor was hypointense compared to the liver on a T1-weighted image and was diffusely hyperintense on a T2-weighted image. Histologically, the tumor consisted predominantly of compact cells with marked cellular and nuclear pleomorphism, but no capsular or vascular invasion were observed. An analysis of the steroidogenic activity of the tumor revealed that the activity of mitochondrial P450c11beta was extremely reduced in the tumor.

Adrenal Cortex Neoplasms↗

Vertical transmission of hepatitis C virus: risk factors and infantile prognosis.

OBJECTIVES: To clarify the incidence and risk factors of the vertical transmission of hepatitis C virus (HCV) and to determine the prognosis of the carrier infants. METHODS: At our hospital, 1,941 non-pathological (non-HIV carriers) Japanese pregnant women were screened for anti-HCV antibodies. Sera of the antibody-positive women were examined by the reverse transcription polymerase chain reaction (RT-PCR) method, and the positive women and their infants were followed by testing HCV-related markers. RESULTS: The HCV carrier rate among the pregnant women was 3.5% (68/1,941). Four among the 65 infants (6.2%) who were successfully followed for more than 6 months developed the HCV carrier-state. Of all the risk factors examined, only the elevation (> or = 110 IU/l) of maternal serum alanine aminotransferase (ALT) was found to be significant for HCV vertical transmission. Seventy-five and 50% of the carrier infants manifested chemical hepatitis and seroconverted to an HCV-RNA-negative status, respectively, during the follow-up period. CONCLUSIONS: The frequency of HCV vertical transmission was 6.2%. Half of the carrier infants became seronegative for HCV-RNA. HCV vertical transmission was significantly affected by the maternal serum ALT level prior to delivery.

Adolescent↗

Synchronous gastric tumors associated with esophageal cancer: a retrospective study of twenty-four patients.

OBJECTIVES: Synchronous gastric tumors (including benign and secondary tumors) associated with esophageal cancer present diagnostic and therapeutic issues. We investigated this synchronous association, and retrospectively determined the frequency of the gastric tumors and the clinical characteristics. METHODS: In a series of 208 patients with esophageal cancer, we investigated the synchronous gastric tumors, as well as the frequency of association, clinicopathological characteristics, diagnosis, treatment, and the clinical outcome after surgery. RESULTS: Twenty-eight gastric tumors were found in 24 patients. Adenocarcinoma was most frequent. Most of these tumors were located at the upper or middle third of the stomach. Eight gastric tumors in six patients could not be detected preoperatively. Six of these tumors including a gastric remnant cancer were detected in the resected stomach, and two leiomyomas were detected during the operation. In one patient in which an endoscope could not pass through the esophagus, a leiomyoma was detected in the resected stomach. For the gastric cancers, total gastrectomy or proximal gastrectomy with lymph node dissections was performed. For the benign tumors, partial resection of the stomach was performed, and endoscopic resection was performed preoperatively for an adenoma. In both the postoperative hospital mortality rate and the survival rate after surgery, there were no significant differences between the patients with and without gastric tumors. CONCLUSIONS: Synchronous gastric tumors associated with esophageal cancer are not rare. When an endoscope cannot pass through the esophagus before surgery, other techniques must be performed to explore the stomach. For these patients, surgical treatment should be adapted positively.

Aged↗

The effects of retinoic acid on alkaline phosphatase activity and tissue-non-specific alkaline phosphatase gene expression in human periodontal ligament cells and gingival fibroblasts.

Alkaline phosphatase (ALP) in human periodontal ligament (HPDL) cells is classified as a tissue-non-specific alkaline phosphatase (TNSALP) by its enzymatic and immunological properties. Since retinoic acid (RA) has been shown as a potent inducer of TNSALP expression in various osteoblastic and fibroblastic cells, we investigated the effects of RA on the level of ALP activity and expression of TNSALP mRNAs in HPDL cells. Cultured cells were treated with desired RA concentrations (0, 10(-7), 10(-6), 10(-5) M) in medium containing 1% bovine serum albumin without serum. ALP activity was determined by the rate of hydrolysis of p-nitrophenyl phosphate and was also assayed in the presence of specific inhibitors. In order to identify the TNSALP mRNA type expressed by HPDL, a set of oligonucleotide primers corresponding to 2 types of human TNSALP mRNA (i.e. bone-type and liver-type) were designed, and mRNA isolated from HPDL was amplified by means of reverse transcription-polymerase chain reaction (RT-PCR). After treatment with RA (10(-6) M) for 4 d, there was a significant increase in the ALP activity of HPDL cells. The use of inhibitors and thermal inactivation experiments showed that the increased ALP activity had properties of the TNSALP type. RT-PCR analysis revealed that bone-type mRNA was highly stimulated in HPDL cells by RA treatment, but the expression of liver-type mRNA was not detected. These results indicated that the upregulation of ALP activity in HPDL cells by RA was due to the increased transcription of bone-type mRNA of the TNSALP gene.

Alkaline Phosphatase↗

[Clinical study of MRSA carrier in sputum].

We studied the clinical aspects of 25 patients (17 male, 8 female, median age 79.4 y.o.) whom MRSA was colonized in sputum from 1989 January to 1994 December. Main underlying diseases were 16 chronic bronchitis and 15 Cerebrovascular damage. Nineteen cases (76%) had catheters, for example 15 urinary tract catheters and 8 nasogastric tube. Twenty-two cases (88%) used previous antimicrobial agent. Fifteen cases (60%) were dead during previous period, and that 14 cases were dead because of respiratory failure within a year after MRSA was colonized in sputum. Nine cases (36%) were able to remove MRSA in sputum, but mortality rate was not different whether MRSA disappear or continue, MIC50 against MRSA (19 strains) were minocycline 12.5 micrograms/ml, arbekacin 6.25 micrograms/ml, vancomycin 0.78 microgram/ml and 16 cases (84.2%) were coagulase type II.

Aged↗

[Report of surveillance on streptococcal toxic shock syndrome in Japan and presentation of the criteria].

A survey was made on the situation of Group A Streptococcal toxic shock syndrome (STSS) based on questionnaires. The survey was divided into two parts. The first survey was done by sending out an outline of the STSS inquiring if any STSS cases were observed by mail to university hospitals, residence training hospital and other major hospitals totaling 2512 institutes. The second survey was subsequently done to the institutes that had STSS cases asking for the clinical course, data and sampling of the bacteria. The diagnosis of STSS was confirmed based on the diagnostic criteria induced by the working group of the United States. We have found 97 cases of STSS which 48.5% had fatal outcomes. There was no significant sex difference in the onset or the mortality rate. It occurred more in the older population, and occurred through out Japan but was not found to be epidemic. The first case was backed in 1978 and it began to increase since 1993, reaching its peak in 1994 and now decreasing in number. Most of the isolated Group A streptococcus were of type M1 and M3. We have modified the United States diagnostic criteria creating a new Japanese criteria, which includes the symptoms of the central nervous system in the term MOF. The aim for the Japanese criteria is to search for the etiology of the disease. The Japanese criteria requires that the disease progresses rapidly and that the patient be free from any conditions that might suppress the immunal system.

Adolescent↗

Penicillin-binding protein 1 of Staphylococcus aureus is essential for growth.

pbpA, a gene encoding penicillin-binding protein (PBP) 1 of Staphylococcus aureus, was cloned in an Escherichia coli MC1061 transformant which grew on a plate containing 512 microg of vancomycin per ml. This gene encodes a 744-amino-acid sequence which conserves three motifs of PBPs, SXXK, SXN, and KTG. The chromosomal copy of pbpA could be disrupted only when RN4220, a methicillin-sensitive S. aureus strain, had additional copies of pbpA in its episome. Furthermore, these episomal copies of pbpA could not be eliminated by an incompatible plasmid when the chromosomal copy of pbpA was disrupted beforehand. Based on these observations, we concluded that pbpA is essential for the growth of methicillin-sensitive S. aureus.

Amino Acid Sequence↗