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Biomedical subjects

M Nasu

Publications and source records attributed to M Nasu.

At least 37 records · Page 2Linked to original sources
PubMed1998

p53 expression in gastric mucosa with Helicobacter pylori infection.

Expression of p53 was examined immunohistochemically in the Japanese monkey model with Helicobacter pylori infection of the gastric mucosa to investigate the association between H. pylori infection and gastric carcinogenesis for a period of 4 years. In the course of these observations, from 3 years after H. pylori inoculation, nuclear staining for p53 was seen in the glandular cells of the mucosa infected with H. pylori, especially in the neck region of the glands. There was a gradual increase in the number of immunopositive cases among the infected animals. Three years after inoculation, three out of six cases, and 4 years after inoculation, four out of six cases exhibited positive staining for p53. Before inoculation, and up to 2 years after inoculation, the infected group showed no immunoreaction for p53. The non-infected group likewise displayed no immunostaining for p53 through 4 years of observation. These results suggest that p53 alterations occur in the H. pylori-infected gastric mucosa and that H. pylori infection may play an important role in gastric carcinogenesis.

Animals↗
PubMed1998

Primary ductal adenocarcinoma of the lacrimal gland.

The morphological similarity of salivary and lacrimal gland tumors is known. Many clinicopathological studies and characteristics of salivary duct carcinoma, which bears histological similarities to mammary duct carcinoma, have been recently reported; however, only one case of lacrimal duct carcinoma is reported. A second case of lacrimal duct carcinoma is presented. A 67-year-old male with a painless mass in the right upper eyelid underwent total removal of the tumor mass. Microscopic examination of the tumor mass revealed ductal adenocarcinoma of the lacrimal gland, which was the equivalent of salivary duct carcinoma. The immunohistological studies of the lacrimal duct carcinoma showed similar results to those reported for salivary duct carcinoma. The recurrent tumor in the subdural spaces was removed 2 years after the initial surgery and the patient is followed as an outpatient.

Adenocarcinoma↗
PubMed1998

Non-Hodgkin's lymphoma presenting with adrenal insufficiency and hypothyroidism: an autopsy case report.

A 55-year-old male presented with an initial manifestation of primary adrenal insufficiency, hypothyroidism. Computed tomography scans showed enlarged bilateral adrenal glands and thyroid. A pathological diagnosis of diffuse large cell, B cell lymphoma was made by a needle biopsy of the adrenal gland. He was treated with combination chemotherapy and adrenal and thyroid hormone replacement. The lymphoma subsequently involved the central nervous system. He died of pneumonia 8 months after the presentation of the first symptom. The postmortem examination demonstrated a complete regression of lymphoma in the bilateral adrenal glands and thyroid. This is an extremely rare case of coexistent lymphoma of the adrenal glands and the thyroid presenting with adrenal failure and hypothyroidism.

Adrenal Insufficiency↗
PubMed1998

Osseointegration in implant-embedded mandible in rats fed calcium-deficient diet: a radiological study.

OBJECTIVE: The purpose of the present study was to investigate osseointegration using radiographs of titanium (Ti) implants into the osteoporotic mandible of rats. MATERIALS AND METHODS: Rats were divided into three groups: first group, which were fed a standard diet throughout (control group), second group which were fed a Ca-deficient diet for only 1 week before implantation (group A), and those which were fed the Ca-deficient diet before and after implantation (group B). On the 7th and 42nd days after implantation, bone changes in those rats were examined by microradiographs and autoradiographs. RESULTS: On the 7th day after implantation, calcification of newly formed bones was lower in groups A and B than in the control group, 45Ca uptake was seen in surrounding bones adjacent to the implant, as well as throughout the mandible. On the 42nd day after implantation, trabecular bone in group A showed radiopacity as seen in the control group. In the alveolar crest and peri-implanted bones in group B, thin bone formation with active 45Ca incorporation was found. CONCLUSIONS: It is suggested that irrespective of the calcium deficiency status in rats, trabecular bones around the implant are restored to a healthy state to some extent by resuming an intake of a necessary amount of dietary calcium. In continued calcium deficiency, osseointegration with the implant and alveolar bone was still observed as in the healthy rats suggesting calcium deficiency is not always a factor to regulate osseointegration of mandibular endosseous implants.

Alveolar Process↗
PubMed1998

In vitro cytotoxic effects of vacuolating cytotoxin produced by clinical isolates of Helicobacter pylori.

The vacuolating cytotoxin produced by Helicobacter pylori is considered to be one virulence factor causing peptic ulceration. In this study, we examined the activity of vacuolating cytotoxin in induction of intracellular vacuolation of rabbit gastric epithelial cells (RGECs). We used culture supernatants of H. pylori as a source of vacuolating cytotoxin and quantitated cytotoxic activity by the MTT method. Intracellular vacuolation of RGECs was observed in the presence of 36 of 57 (63%) clinically isolated H. pylori strains. However, there were no differences in the incidence of H. pylori strains with positive vacuolating cytotoxin (Tox+) among patients with gastritis, gastric ulcers or duodenal ulcers. The MTT assay showed that the cytotoxic activity of H. pylori supernatants obtained from patients with gastric ulcers was significantly higher than in patients with gastritis (p < 0.01), but was not different to duodenal ulcer patient supernatants. Similar results were also observed in Tox+ isolates, however, there were no significant differences between patients with regard to the incidence of vacuolating cytotoxin-negative isolates. Although our data may not indicate a clear correlation between prevalence of vacuolating cytotoxin and clinical manifestations, they suggest that H. pylori harboring vacuolating cytotoxin may particularly induce damage to the gastric epithelium in patients with gastric ulcers.

Animals↗
PubMed1998

Sensitive detection of Helicobacter pylori in gastric aspirates by polymerase chain reaction.

The detection of Helicobacter pylori in gastric aspirate was examined by using the polymerase chain reaction (PCR) method for amplifying a specific fragment of the urease gene A. The ability of PCR to amplify H. pylori-specific DNA was analyzed by Southern hybridization with an internal oligonucleotide probe. Twenty-two H. pylori strains from clinical isolates and reference strains were studied, and all H. pylori strains yielded a 356-bp product that hybridized with the oligonucleotide probe, whereas no amplification was evident with 18 non-H. pylori strains. This could detect as little as 50 CFU of H. pylori in pure culture and 0.1 pg of purified chromosomal DNA. A total of 50 dyspeptic patients were examined for the presence of H. pylori by culture, the rapid urease test and histological examination of antral biopsy samples as well as by PCR in gastric juice aspirate samples. The gold standard for the presence of H. pylori was established by minimum concordance of two of three tests performed on biopsy specimens. With this gold standard, 34 of the 50 patients were considered to harbor H. pylori infection. PCR correctly identified 32 (94.1%) of these 34 infected patients. PCR had the best combination of sensitivity and specificity in assessing the correct diagnosis of H. pylori as compared with those of the rapid urease test and culture. Moreover, we established a fast and simple method for use by improvement of DNA extraction. PCR of the gastric aspirate was shown to be a sensitive and specific procedure which may be an attractive alternative to methods currently used for diagnosis of H. pylori infection.

Adult↗
PubMed1998

[In vitro activities of faropenem against clarithromycin resistance Helicobacter pylori isolates].

Agar dilution and semi-solid agar dilution were used to determine the MIC of faropenem (FRPM) against 24 H. pylori isolates. FRPM was active against clarithromycin resistance H. pylori isolates. And, the MICs obtained by both methods were in agreement. The results suggest that FRPM was not affected by pH and is a clinically useful oral antibiotic for the eradication therapy of H. pylori infections.

Anti-Bacterial Agents↗
PubMed1998

[Case report: subcutaneous abscess and thoracic empyema caused by Alcaligenes xylosoxidans].

Alcaligenes xylosoxidans is a glucose-nonfermentative gram-negative rod which usually exists in the environment. This organism while causing pneumonia, sepsis, meningitis and urinary tract infection in the compromised host, rarely causes thoracic empyema. We report a case of thoracic empyema and subcutaneous abscess due to A. xylosoxidans. A 74-year-old male, who had undergone right total pneumonectomy for chronic necrotizing pulmonary aspergillosis a year ago, was admitted to our hospital because of fever. CT scans of the chest revealed a subcutaneous abscess and empyema. Empyema and subcutaneous pus were aspirated. Culture of materials produced A. xylosoxidans. There was no significant change on symptoms and examinations despite therapy with PIPC 4 g/day and thoracic drainage. Finally, surgical treatment was required and the patient was cured.

Abscess↗
PubMed1998

[Clinical study on mechanism of Pneumocystis carinii pneumonia by polymerase chain reaction].

Pneumocystis carinii is a human respiratory pathogen which causes fatal pneumonia in patients under immunosuppressed or immune deficient conditions. Recent work have documented the usefulness of the polymerase chain reaction (PCR) method in the detection of P. carinii from clinical samples. Therefore, we described our experience in using PCR method in the detection of P. carinii from respiratory samples. In our study, bronchial washing or BALF were good for diagnosis of P. carinii pneumonia (PCP) by PCR. However, PCR method in the detection of P. carinii from swab or sputum was too sensitive because small numbers of P. carinii organisms might be insignificant in causing the disease. It might reveal colonization or asymptomatic carrier state in the upper respiratory tract. Therefore, our result suggested that colonization or asymptomatic carrier state in the upper respiratory tract could eventually evolve into PCP. This would also facilitate basic progress in the pathology or epidemiology of P. carinii infection. In addition, an usefulness of prophylactic therapy for PCP was documented by PCR.

Bronchoalveolar Lavage Fluid↗
PubMed1998

[A mechanism of clarithromycin resistance in Helicobacter pylori].

The aim of this study was to elucidate the mechanism of clarithromycin (CAM) resistance in laboratory strains and clinical isolates of Helicobacter pylori. The CAM resistance in laboratory strains was induced in vitro by CAM exposure. The majority of CAM-resistant strains were highly resistant to CAM (MICs > 100 micrograms/ml). These CAM-resistant strains also showed cross resistance to azithromycin, rokitamycin and clindamycin. The sites of point mutations in these resistant strains were identified as follows; the conserved domain V of genes encoding 23S rRNA were amplified first by PCR and this PCR products (1.4 kb) were subsequently digested with BsaI and MboII and RFLP patterns were analyzed. 1.4 kb amplicons of CAM-susceptible strains yielded two DNA bands of 1000 bp and 400 bp when digested with BsaI but no digestion product was seen by MboII digestion. In contrast to this, two types of RFLP patterns were observed for the resistant strains induced in vitro by CAM; one was the formation of three bands (700 bp, 400 bp and 300 bp) after BsaI digestion, and the other was the formation of two bands (approximately 700 bp) by MboII digestion. RFLP patterns of CAM-susceptible and CAM-resistant clinical isolates obtained from patients before and after CAM medication were similar to those observed for the CAM-susceptible strains and CAM-resistant strains developed in the laboratory. These results strongly suggest that the CAM resistance of H. pylori was caused by point mutation of 23S rRNA.

Anti-Bacterial Agents↗
PubMed1998

Development of a direct in situ PCR method for detection of specific bacteria in natural environments.

We applied HNPP (2-hydroxy-3-naphthoic acid-2'-phenylanilide phosphate) to direct in situ PCR for the routine detection of specific bacterial cells at the single-cell level. PCR was performed on glass slides with digoxigenin-labeled dUTP. The digoxigenin-labeled PCR products were detected with alkaline phosphatase-labeled antidigoxigenin antibody and HNPP which was combined with Fast Red TR. A bright red fluorescent signal was produced from conversion to HNP (dephosphorylated form) by alkaline phosphatase. We used the ECOL DNA primer set for amplification of ribosomal DNA of Escherichia coli to identify cells specifically at the single-cell level in a bacterial mixture. High-contrast images were obtained under an epifluorescence microscope with in situ PCR. By image analysis, E. coli cells in polluted river water also were detected.

Alcaligenes↗
PubMed1998

Serological assessment of the early response to eradication therapy using an immunodominant outer membrane protein of Helicobacter pylori.

Eradication of Helicobacter pylori infection cures gastritis and prevents recurrence of peptic ulcers. Endoscopy is usually used to evaluate the effectiveness of eradication therapy. We designed a new noninvasive assay system for the early evaluation of eradication of H. pylori infection in which a crude H. pylori outer membrane protein preparation (HPOmp) is used as an antigen, and we determined the sensitivity and specificity of the serological assay system. Immunoblot analysis showed that anti-HPOmp antibodies reacted to a protein with a molecular mass of approximately 29 kDa. In those patients who responded to therapy, the anti-HPOmp immunoglobulin G (IgG) titers measured by enzyme-linked immunosorbent assay (ELISA) at 1 month after the end of therapy were significantly lower than those before treatment (34.8% reduction; P < 0.001), and the posttreatment reduction in the antibody titer was significantly greater than that of the titer measured with a commercially available anti-H. pylori IgG ELISA (34.8% versus 16.1%; P < 0.001). When a 25% reduction of anti-HPOmp IgG titer at 1 month after the end of treatment was taken as the cutoff value for H. pylori eradication, the sensitivity and specificity of our new assay were 75% (51 of 68 treatment responders) and 96% (22 of 23 nonresponders), respectively. Our results indicate that the novel serological test with HPOmp might be a clinically useful tool for assessment of eradication of H. pylori.

Adolescent↗
PubMed1998

Diversity in protein synthesis and viability of Helicobacter pylori coccoid forms in response to various stimuli.

The viability of the coccoid forms of Helicobacter pylori was evaluated by assessing protein synthesis. Metabolic labeling studies showed the synthesis of proteins and the specific protein profiles of H. pylori coccoids produced under various conditions. Harsh conditions such as aerobiosis and starvation (lack of horse serum) in the culture did not affect the synthesis of proteins in the coccoids. Lowering of the pH to that of gastric secretions induced expression of several proteins in the coccoids. However, the coccoids produced under prolonged microaerobic conditions exhibited a profile of acid stress-induced protein expression different from that induced by aerobiosis or starvation. Our data suggest that coccoid H. pylori exhibits diversity in viability following exposure to different stresses and that the response to acid stress of coccoid H. pylori could be involved in infection of the host stomach.

Acids↗
PubMed1998

Evaluation of PCR for detection of DNA specific for Aspergillus species in sera of patients with various forms of pulmonary aspergillosis.

Pulmonary aspergillosis is classified into invasive, saprophytic, and allergic forms. In this study, we evaluated the usefulness of PCR for differentiating between different forms of aspergillosis or in monitoring disease activity during treatment by detecting DNA specific for Aspergillus species in the serum. Nested PCR was used to detect Aspergillus DNA in the sera of 30 patients with various forms of pulmonary aspergillosis. The results were compared with those of latex agglutination tests for detecting galactomannan antigen. We also examined the serial changes in the results of nested PCR during and after treatment of a subgroup of patients with invasive pulmonary aspergillosis with amphotericin B. The highest proportion of positive nested PCR results were in patients with invasive aspergillosis (10 of 12; 83%), while patients with pulmonary aspergilloma had the lowest frequency of positive tests (1 of 9; 11%). These results suggested that the sensitivity of the nested PCR depends on the extent of invasion by Aspergillus species. Serial assays showed that the results of nested PCR became negative shortly after commencement of antifungal treatment and that such changes did not correlate with clinical responsiveness to treatment. Our results indicate the potential usefulness of nested PCR with serum samples for the diagnosis of invasive aspergillosis and the detection of a shift in the status of infection from a noninvasive type to invasive aspergillosis. However, the results of the nested PCR did not correlate with the response to antifungal treatment.

Adult↗
PubMed1998

Carboxyl-terminal parathyroid hormone fragments stimulate type-1 procollagen and insulin-like growth factor-binding protein-5 mRNA expression in osteoblastic UMR-106 cells.

The effects of carboxyl-terminal (C-) PTH fragments, (35-84), (53-84) and (69-84), on the proliferation and function of osteoblastic UMR-106 cells were compared with those of amino-terminal (N-) (1-34) and intact (I-) (1-84) PTH. I-PTH as well as N-PTH at 10(-8)M significantly inhibited [3H] thymidine incorporation and stimulated alkaline phosphatase activity in UMR-106 cells. No C-PTH fragments affected them. In contrast, the expression of type-1 procollagen mRNA in these cells was stimulated by all C-PTH fragments, inhibited by N-PTH and not affected by I-PTH. All C-PTH fragments except (69-84) as well as N-PTH and I-PTH stimulated IGFBP-5 mRNA expression. The present study suggests that the C-portion of the PTH molecule exercises biological activities in mRNA expression of type-1 procollagen as well as IGFBP-5 in osteoblasts, and that it might be involved in the anabolic action of PTH on bone in vivo.

Cell Line↗
PubMed1998

Age-dependent changes in body composition in postmenopausal Japanese women: relationship to growth hormone secretion as well as serum levels of insulin-like growth factor (IGF)-I and IGF-binding protein-3.

The present study was performed to investigate the age-dependent changes in body composition and the possible role of growth hormone (GH), insulin-like growth factor (IGF)-I and IGF-binding protein-3 (IGFBP-3) in these changes in postmenopausal Japanese women. A total of 161 Japanese women aged 45-88 years (mean 62) were enrolled in the cross-sectional study. Body composition (bone mineral content (BMC), lean body mass (LBM) and fat) was measured by dual-energy X-ray absorptiometry, and the percentage of BMC, LBM and fat was calculated by dividing each absolute value of body composition by total body mass. Urinary GH concentration divided by creatinine in nocturnal urine samples collected just after waking was used as an index of endogenous GH secretion. Serum levels of IGF-I and IGFBP-3 were measured by RIA. Urinary GH levels as well as serum levels of IGF-I and IGFBP-3 declined with age. BMC, %BMC and LBM also declined with age, while fat mass and %fat did not obviously change with age. Urinary GH levels as well as serum levels of IGF-I and IGFBP-3 correlated positively with BMC, even if age was taken into account. On the other hand, urinary GH correlated negatively with fat and %fat. In contrast, serum levels of IGF-I and IGFBP-3 correlated positively with fat and %fat. LBM did not correlate with either urinary GH or serum IGFBP-3 levels but exhibited a weakly positive correlation with serum IGF-I level. The present study suggests that the GH-IGF-I-IGFBP-3 axis positively regulates bone mass, and that GH and IGF-I-IGFBP-3 inversely regulate fat mass, i.e. GH negatively and IGF-I-IGFBP-3 positively regulates it.

Aged↗
PubMed1998

[Evaluation of new method for diagnosis of opportunistic fungal infection].

New methods for the possible presence DNA specific for Aspergillus or Trichosporon species were developed. In aspergillus PCR, Aspergillus l8S rRNA encoding gene was amplified from five strains of Aspergillus species by the nested PCR but not from other microorganisms. Results of preliminary investigation of this method demonstrated efficient detections of Aspergillus species in serum samples of rats model of aspergillosis and 29 patients with invasive aspergillosis. In trichosporon PCR, Trichosporon 26S rRNA encoding gene was amplified from two strains of Trichosporon species, and detected by the nested PCR in 64 % of serum samples of patients with trichosporonosis, while glucuronoxylomannan antigen was detected in 55 % of samples. The high sensitivity and specificity of the nested PCR indicate that the assay can provide early diagnosis with sufficient accuracy to be clinically useful for patients with opportunistic fungal infection.

Adult↗