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Biomedical subjects

H Sakamoto

Publications and source records attributed to H Sakamoto.

At least 667 records · Page 37Linked to original sources
PubMed1990

Isolation of an amplified DNA sequence in stomach cancer.

By use of the in-gel DNA renaturation method, the presence of amplified DNA sequences was demonstrated in KATO-III, a cell line established from a signet ring cell carcinoma of the stomach. A DNA fragment from one of these amplified regions in KATO-III cells was cloned and designated SAM0.2; the locus containing the SAM0.2 fragment was referred to as SAM. The SAM locus was shown to be amplified not only in KATO-III cells, but also in three of 24 surgical specimens of stomach cancers and in two of 13 xenografts of human stomach cancers, all of these specimens being poorly differentiated adenocarcinoma or mucinous adenocarcinoma of the stomach. The SAM locus was not amplified in 14 cell lines of cancers of other organs or in 42 surgical specimens of lung cancers.

Adenocarcinoma↗
PubMed1990

Ultrastructure of rectal biopsy specimens in unusual familial ataxia with cerebrospinal fluid abnormality.

The ultrastructure of rectal biopsy specimens from a 60-year-old woman of unusual familial ataxia with cerebrospinal fluid abnormality was investigated. She had two male siblings similarly affected and a close consanguinity in the family. Meissner's plexus neurons, Schwann cells, fibroblasts and smooth muscle cells within the rectum contained intracytoplasmic eosinophilic inclusions (IEIs) with or without intensely eosinophilic granules. Ultrastructurally the IEIs were composed of a membrane-bound, fine granular material with or without dense cores. The IEIs resembled intracytoplasmic inclusions seen in various cells of the central nervous system from a male autopsied sibling. The clinically and morphologically similar finding in the two siblings suggests an autosomal recessive inherited metabolic disorder previously unreported.

Biopsy↗
PubMed1990

[Five cases of listeriosis in the elderly].

We reported five cases of listeriosis (sepsis and meningitis) in the elderly in our hospital during the last 4 years, where no cases of listeriosis had been found. These 5 cases had diabetes mellitus, lung cancer, chronic respiratory failure, gastric ulcer and aplastic anemia respectively as their underlying diseases. At the onset of listeriosis, 3 cases received corticosteroid and 3 cases received H2-blocker. 2 patients were cured and 3 patients died. Three autopsy cases had meningitis or meningoencephalitis and 2 cases of these autopsy cases had granulomatous changes in these spleens. In serotypes of Listeria monocytogenes (L. monocytogenes), 4 cases were 4b and 1 cases was 1b. All 5 strains were resistant to 3rd generation cephems. Wide uses of 3rd generation cephems and H2-blocker may be one of the reasons for the recent increase of listeriosis. Ingestion of contaminated food is the pathogenetic mechanism for initiating L. monocytogenes infections. And following the change of eating habits and the increase of imported foods, food-born listeriosis may increase. We suppose the increase of L. monocytogenes infections and must give attention to L. monocytogenes infections.

Age Factors↗
PubMed1990

Gene heterogeneity for tetracycline resistance in Staphylococcus spp.

Nucleotide sequences related to four tet genes were studied by hybridization in 183 clinical Staphylococcus isolates. tet(K) predominated in strains resistant only to tetracycline, while tet(M) was responsible for combined tetracycline and minocycline resistance. In strains harboring both genes, they contributed additively. tet(L) was detected in only five strains, and no hybridization was observed with tet(O).

DNA, Bacterial↗
PubMed1990

Deletions affecting hemolytic and toxin activities of Bordetella pertussis adenylate cyclase.

The Bordetella pertussis cyaA gene encodes a virulence factor which is a bifunctional protein exhibiting calmodulin-sensitive adenylate cyclase and hemolytic activities (P. Glaser, H. Sakamoto, J. Bellahov, A. Ullmann, and A. Danchin, EMBO J. 7:3997-4004, 1988). We characterized the hemolytic and toxin activities of the 200-kilodalton (kDa) bifunctional (CyaA) protein and showed that, whether cell associated or secreted, the 200-kDa CyaA protein carries hemolytic and toxin functions. The catalytically active 45-kDa form of adenylate cyclase released by proteolytic digestion of the 200-kDa CyaA protein displayed neither hemolytic nor toxin activities. We constructed in-phase deletions in the 3' region of the cyaA gene, which presumably carries the hemolytic determinant, and showed that the resulting proteins exhibited wild-type adenylate cyclase activity and were secreted without processing into culture supernatants. The hemolytic activities of these mutant CyaA proteins were severely reduced, and their toxin activities were abolished. These results suggest that the structural integrity of the 200-kDa CyaA protein is necessary for toxin activity and that distinct structural determinants within the CyaA protein are involved in secretion, pore formation, and entry into target cells.

Adenylyl Cyclases↗
PubMed1990

Synthesis and secretion of Bordetella pertussis adenylate cyclase as a 200-kilodalton protein.

Bordetella pertussis, the etiological agent of whooping cough, synthesizes a calmodulin-sensitive adenylate cyclase that is suspected to play a major role in the virulence of this bacterium. We show that adenylate cyclase synthesized as a 200-kilodalton protein is the product of the cyaA gene and that various virulent Bordetella species secrete this high-molecular-weight polypeptide without apparent proteolytic processing. When submitted to trypsin digestion, the 200-kilodalton protein was converted to a stable 45- to 50-kilodalton species. This corresponds to the size of the enzyme previously purified from a culture supernatant. The molecular heterogeneity reported for the various identified forms of adenylate cyclase could therefore result in part from proteolytic degradation or molecular aggregation of the major 200-kilodalton form of the enzyme.

Adenylyl Cyclases↗
PubMed1990

Effects of single and multiple moxibustions on activity of platelet function, blood coagulation and fibrinolysis in mice.

The effects of single and multiple moxibustions on platelet function, blood coagulation and fibrinolytic activity in ddY mice were studied. The increase in platelet aggregation and ATP-release after a single moxibustion was dependent on moxa weight and the kind of platelet stimulus. Blood coagulative activity tended to increase in the early phase after a single moxibustion. However, multiple moxibustions maintained the homeostasis on blood coagulation and fibrinolytic activity. This investigation suggests that the effects of moxibustion on platelet functions and coagulative and fibrinolytic activities cause an enhancement of the phagocytic activity in the host defense mechanism.

Animals↗
PubMed1990

Histopathologic and immunohistochemical findings in gelatinous drop-like corneal dystrophy.

A cornea with gelatinous drop-like corneal dystrophy was examined by histochemical and immunohistochemical techniques. Pretreatment of the sections with potassium permanganate did not decrease the staining with Congo red dye. Immunohistochemically, amyloid deposits in the cornea with this disease almost did not stain with antibodies to amyloid protein AA and AA-3. However, the corneal epithelium reacted distinctly with antibodies to amyloid protein AA and AA-3. Cross-reactivity with antibodies to protein AA and serum precursor of protein AA has been reported and protein AA-3 is the synthesized peptide corresponding to the amino acid sequence 37-47 of the human amyloid protein AA molecule. The present study suggests at least that corneal epithelial cells with gelatinous drop-like corneal dystrophy may produce a precursor of amyloid related to protein AA-3.

Adult↗
PubMed1990

Myocardial infarction induced by coronary venous thrombosis--an experimental study.

In a previous study, we proved experimentally that transmural infarction was produced in the area of the left anterior descending artery (LAD) by coronary sinus occlusion attributable to thrombus formation. In an attempt to produce infarction due to thrombus formation and to investigate the influence of thrombosis, the anterior interventricular vein (AIV) was occluded in this study. In each of 6 adult mongrel dogs, a balloon-tipped catheter was wedged in the AIV via the jugular vein. After the occlusion of blood flow by inflation of the balloon, thrombin (30-50 IU) was injected into the AIV to produce thrombi and the balloon was removed 60 min later. As a result, ischemic changes of ST and T in an ECG were clearly observed in all 6 dogs, and serum levels of myocardial enzymes supported the development of myocardial necrosis. Coronary arteriography performed 48 hours after the occlusion of the AIV showed normal findings in all 6 dogs, and residual thrombi in the AIV were observed in 5 dogs by coronary venography. In these 5 dogs, very local contraction band necrosis (CBN) was noted in the epicardium surrounding the AIV. These experimental findings indicate the following: 1) CBN can also be induced by coronary venous occlusion, 2) once the occlusive mechanism acts on the coronary venous system, the changes which are clinically similar to myocardial infarction can be induced regardless of its causes, 3) ischemic changes in myocardium can be localized in the epicardium irrespective of its causes. Therefore, these findings are considered to be important in the investigation of the clinical onset mechanism of myocardial infarction.

Animals↗
PubMed1990

Changes in brain lipid composition in thiamine deficient rats.

Brain lipid composition was studied in thiamine deficient rats treated with thiamine antimetabolites (oxythiamine: OT, and pyrithiamine: PT) and thiamine deficient diet (TDD). After intraperitoneal injection of OT (40 mg/kg/day) or TDD feeding for 6 days, body weight gain decreased. However, the PT (500 micrograms/kg/day) treated rats or the pair fed control (PFC: TDD + thiamine of 5 mg/kg, i.p.) showed no decrease in body weight gain compared with the regular diet control (C). Brain lipid levels (total lipid, total cholesterol, triglyceride, phospholipid, sphingomyelin and cerebroside) were examined in four brain regions (cerebral cortex, subcortical structure, brain stem and cerebellum). Total lipid level increased in four regions in OT or TDD treated rats, but total lipid level in the cerebellum in PT treated rats decreased. Total cholesterol level increased in all treated rats, while the triglyceride level in the brain stem decreased dramatically in OT or TDD treated rats. Cerebroside levels of four regions in the PT, OT or TDD group remarkably decreased, and PFC rats showed a significant improvement of the decrease in cerebroside level. It is conceivable that these changes in brain lipid composition provided some clues for the histological and morphological changes of the brain as manifested by the myelin degradation in acute thiamine deficiency.

Animals↗
PubMed1990

[Studies on O'Leary's plaque control record in initial periodontal treatment. 1. Relation between PCR and different brushing methods in 1982-1986].

The purpose of this study was to investigate the effects of different methods of brushing on plaque removal, using O'Leary's plaque Control Record during initial preparation. The results were as follows: 1. There were many 40-50 year-old patients and they showed a 63.0 percent first visit Plaque Control Record average. 2. Many of the patients entering the clinic had periodontal disease in mild stages. 3. In most cases the toothbrushing methods were the Rolling method and the Modified Stillman's method. Of the patients, 73.5% achieved Plaque Control scores at the 20 percent level. 4. Of the patients who had achieved a Plaque Control Record at the 20 percent level, half of the patients instructed to brush using the Rolling method had developed moderate forms of periodontal diseases, and half of the patients instructed to use the Modified Stillman's method had developed mild forms of periodontal disease. There is a close relationship between toothbrushing methods and the progression of diseases, and this shows that Plaque removal methods should be controlled.

Adult↗
PubMed1990

[Establishment of permanent atrial fibrillation and time course of the amplitude of the f wave].

Atrial fibrillation is one of the arrhythmias that increase with increasing age. In this study we compared transition intervals from sinus rhythm to permanent atrial fibrillation and the time course of the f wave amplitude immediately after the transition between 32 younger (less than 65 years) and 44 elderly patients (greater than or equal to 65 years) in whom transition from sinus rhythm to permanent atrial fibrillation was confirmed on serial ECG recordings. Each group was classified into three categories according their underlying diseases: hypertensive heart disease, valvular disease, and lone atrial fibrillation. In patients with hypertensive heart disease or lone atrial fibrillation, there was no significant difference in the transition intervals between the younger and the elderly groups. In both groups the transition intervals were significantly (p less than 0.05) longer in patients with lone atrial fibrillation than those in patients with hypertensive heart disease (44.6 vs. 12.5 months in younger and 26.8 vs. 12.9 months in elderly). A significant positive correlation (r = 0.58, p less than 0.01) was observed between the final P wave and the initial f wave amplitude on establishment of permanent atrial fibrillation in all patients. In the younger group, the initial f wave amplitude of patients with valvular disease (0.27 +/- 0.04 mV, mean +/- SE) was significantly larger than those of patients with hypertensive heart disease (0.15 +/- 0.03 mV, p less than 0.05) and of patients with lone atrial fibrillation (0.16 +/- 0.01 mV, p less than 0.05). The f wave amplitude of valvular disease was significantly decreased after 1 year (0.22 +/- 0.03 mV, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Amplification and expression of a multidrug resistance gene in human glioma cell lines.

Two human glioma cell lines were examined for multidrug resistance (MDR). A vincristine (VCR)-resistant glioma cell line showed a cross resistance to Adriamycin (doxorubicin, ADR) and etoposide (VP-16) to varying extents, suggesting the presence of MDR; the resistance to VCR was considerably decreased by calcium entry blockers. On the other hand, another VCR-sensitive glioma cell line exhibited no cross resistance to ADR or VP-16. Double minute chromosomes and homogeneously staining regions as well as clonal aberrations of chromosome 7 were not observed in cytogenetic studies of multidrug-resistant and multidrug-sensitive glioma cell lines. In Northern and Southern blot analyses, MDR gene 1 (MDR1) messenger ribonucleic acid (mRNA) was shown to be overexpressed without any amplification of the MDR1 gene in multidrug-resistant glioma cell lines as compared to multidrug-sensitive glioma cell lines. It would be reasonable to suggest that amplification of the MDR1 gene may not be a sine qua non for acquisition of MDR and that the MDR1 mRNA level may be correlated with the extent of MDR.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1990

Concentrations of atrial natriuretic peptide in plasma and urine of kidney disease patients.

Concentrations of human atrial natriuretic peptide-like immunoreactivity (hANP-LI) were measured by a highly sensitive and specific radioimmunoassay (Biochem Biophys Res Commun 1986;137:231-6) in normal subjects and in renal disease patients without accompanying congestive heart failure, hypertension, edema, diabetes, or pregnancy. We attempted to clarify whether the hANP-LI concentration in plasma was increased by loss of renal mass. We found no correlation between the hANP-LI concentration in plasma and creatinine clearance (Ccr, 4.6-122.3 mL/min) in patients with renal disease (n = 63, r = -0.196), nor between hANP-LI concentrations in plasma and urine (n = 97, r = -0.207). The fractional excretion of hANP (FEhANP) correlated significantly with Ccr (n = 63, r = 0.520, P less than 0.01) and with FENa (n = 35, r = -0.503, P less than 0.01). Increased FEhANP in patients with chronic renal failure may have resulted because of an increase in single-nephron glomerular filtration rate similar to the FENa increase in these patients. The present data indicate that decreased renal function itself does not increase the concentration of hANP-LI in plasma.

Adolescent↗
PubMed1990

[Second serogroup of Legionella pneumophila isolated from a patient with fulminant pneumonia].

A 67-year-old female was admitted to our hospital, because of high fever and dry cough. She had undergone semiradical hysterectomy and radiation therapy for carcinoma of the uterine cervix one year previously. Her chest roentgenograms on admission showed lobar consolidation of the left upper lobe. Antibiotics were administered but her general condition and pulmonary consolidation did not improve. As Legionellosis was highly suspected, we performed bronchoscopic examinations. Bronchial mucosa was almost normal with no secretion, and Legionella was isolated from the specimen obtained bronchoscopically. Six days later, L. pneumophila serogroup 2 was isolated and identified from an intratracheal aspiration, and serological diagnosis was made by indirect immunofluorescence antibody. We could also detect the bacteria in the BALF by immunofluorescence microscopy and in the tissue of the TBLB specimen with the ABC method.

Aged↗
PubMed1990

[Lung injuries and serial bronchoalveolar lavage findings in patients with summer-type hypersensitivity pneumonitis].

To evaluate acute lung injuries and their persistence in patients with summer-type hypersensitivity pneumonitis, repeated bronchoalveolar lavage (BAL) and pulmonary function tests were performed. BAL was performed on 36 occasions in 17 patients with hypersensitivity pneumonitis. Nineteen BAL procedures in 16 cases were done during the active phase within the three hospital day and BAL was repeated in 8 cases during inactive phase. Anti-Trichosporon cutaneum antibodies were detected in all of 15 cases examined using the Ouchterlony method and indirect immunofluorescent methods. The number of total BAL cells, lymphocyte and neutrophils were increased in the active phase, and OKT4/OKT8 was quite low (0.39). As the disease became inactive, the number of total BAL cells, lymphocytes and neutrophils decreased. On the other hand OKT4/OKT8 increased quickly. Significantly negative correlations were recognized between the number of BAL lymphocytes and %VC, and lymphocytes and %DLCO4. More improvements in BAL findings, %VC and %DLCO one year after acute episodes were seen in cases that moved house than cases that did not move, and these often relapsed. We concluded that complete clearing of the patient's house or moving out, if necessary, were needed to avoid relapse and persistent lung injuries.

Adolescent↗
PubMed1990

[The development of a highly sensitive IgE immunoradiometric assay using monoclonal antibodies].

We have developed two-site immunoradiometric assay (IRMA) for quantitation of human serum IgE, using two different anti-IgE monoclonal antibodies which recognize different epitopes on IgE molecule. We obtained 25 different monoclonal antibodies classified seven groups, and then two different monoclonal antibodies were selected for bead coater and tracer after checking the titer and specificity of each antibody. IgE IRMA we developed here showed good performance in terms of specificity, sensitivity and reproducibility. No cross-reactivity to IgG, IgM and albumin in the level of normal range was observed. The sensitivity for IgE assay was 0.6 x 10(-3) IU/tube and measurable range was 0.01-20.0 IU/tube (0.5-10(3) IU/ml). Coefficient of variations of Intra assay were 2.2-4.3% and average recovery yield was 92.5-108%. Good correlations with Phadebas IgE PRIST and Pharmacia IgE RIA were obtained i.e., y = 1.12x-0.19 (r = 0.96) and y = 0.97x-5.9 (r = 9.7), respectively. These results indicate that the assay system will contribute much to the routine diagnosis for atopic allergy disease and parasitic infections.

Antibodies, Monoclonal↗