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Biomedical subjects

K Saitoh

Publications and source records attributed to K Saitoh.

At least 289 records · Page 16Linked to original sources
PubMed1991

Dynemicins O, P and Q: novel antibiotics related to dynemicin A isolation, characterization and biological activity.

New antibiotics, dynemicins O (3), P (4) and Q (5), were isolated from the culture broth of Micromonospora chersina M956-1, the dynemicin A (1)-producing strain. An ethyl acetate extract of a tank culture was roughly separated by a column of Diaion SP-800 and was further purified by combining a variety of column chromatographies to afford a few mg of compounds 3, 4 and 5. Their structures, analyzed from the spectral data, had a bridging phenylene group, a vic-diol and an oxo group in place of the respective 1,5-diyn-3-ene bridge, the epoxide ring and the carboxyl group in dynemicin A. Their biological activities were evaluated against bacteria and tumor cells.

Alkenes↗
PubMed1991

Dynemicins, new antibiotics with the 1,5-diyn-3-ene and anthraquinone subunit. I. Production, isolation and physico-chemical properties.

Dynemicin A, a novel antibiotic containing the bicyclo[7.3.1]-1,5-diyn-3-ene and 1,4,6-trihydroxyanthraquinone functionalities, was isolated from the culture broth of Micromonospora chersina sp. nov. M956-1. The antibiotic exhibited potent in vitro antibacterial and cytotoxic activity, and in in vivo, it cured mice from lethal Staphylococcus aureus infection and prolonged survival time of mice inoculated with murine tumors. Three satellite components, dynemicins L, M and N, were also isolated from the culture broth and chemically characterized.

Animals↗
PubMed1991

[A study on crosstalk correction in dual energy acquisition of 123I-MIBG and 201TlCl in myocardial SPECT].

In the simultaneous dual energy acquisition, energy spectrums of two radionuclides crosstalk each other and this phenomenon is a cause of the poor quality of images. In order to obtain the image of high quality in dual energy acquisition of 123I-MIBG and 201TlCl, a crosstalk correction method was originated. The crosstalk from 201Tl to 123I window (R1) and the crosstalk from 123I to 201Tl window (R2) were determined by the cardiac phantom studies. R1 and R2 showed almost constant value throughout the myocardial wall. The crosstalk correction was performed using R1 and R2. After the crosstalk correction, the defect region placed in the cardiac phantom was detected more clearly both in visual interpretation and in quantitative analysis. The crosstalk correction method with R1 and R2 was applied to some clinical cases. By the crosstalk correction, the quality of image was improved and a false defect caused by crosstalk disappeared in a clinical case. The crosstalk correction was considered to be useful for improving the quality of image on dual energy acquisition.

3-Iodobenzylguanidine↗
PubMed1991

[A case of an intracranially located esthesioneuroepithelioma].

A 1-year-8-month-old boy was admitted to our service on September 30, 1986, complaining of nausea, vomiting and consciousness disturbance lasted for about 2 weeks. In CTs, right frontal cystic mass which was homogeneously enhanced by contrast media was revealed. Neither hypervascularity nor tumor staining were seen angiographically. On October 9, 1986, total removal of the tumor was performed. The tumor was located extracerebrally in the right anterior cranial fossa, but was covered with arachnoid membrane. The tumor showed tight adhesion with falx cerebri, particularly at crista galli where an invasive infiltration was seen. Light microscopic examination demonstrated oval or spherical small cells arranged multilobularly with rosette like formation and numerous mitoses. Ultrastructurally, cilia, microvilli and junctional complexes were observed. No dense-cored secretory granules were found in the tumor cells. Immunohistochemical study on this tumor showed negative NF and GFAP; positive NSE, S-100, vimentin and keratin. From these findings, the tumor was diagnosed as esthesioneuroepithelioma. Postoperatively, irradiation and chemotherapies were also performed, and the patient showed uneventful course. On January 31, 1987, he was discharged on his foot, and no recurrent or metastatic signs could be found until the end of March of 1990.

Brain Neoplasms↗
PubMed1991

[Parameter in fulminant hepatitis].

Serum complement hemolytic activities (CH 50) and plasma prothrombin time (PTT) of patients with fulminant hepatitis (FH, 11 cases of acute type and 11 cases of subacute type), severe acute hepatitis (AH-S, 9 cases) and typical acute hepatitis (AH-T, 20 cases) were examined. AH-S was diagnosed as AH patients with PTT under 40% and without hepatic coma. Survival rates were 100% in AH-S, 45.5% (5/11) in acute type of FH and 9.1% (1/11) in subacute type of FH. The mean levels of CH 50 on their admission were 42.6 U/ml in AH-T, 28.8 U/ml in AH-S and 13.1 U/ml in FH. CH50 levels in acute hepatitis decreased in parallel to the severity of the disease and correlated with PTT (r = 0.809). In many cases of FH and almost all cases of AH-S, CH50 levels changed more slowly than those of PTT. The patients with AH-S and subacute type of FH showed a prolonged PTT and the normal levels of CH 50 in their acute phase. These results indicate that CH50 and PTT could be useful markers differentiating subacute type from acute type of fulminant hepatitis.

Acute Disease↗
PubMed1991

[A case of systemic xanthogranulomatosis with an intracranial lesion: immunohistochemical study].

The authors describe a case of a 42-year-old woman with systemic xanthogranulomatosis who primarily manifested bilateral intraorbital tumors, generally effecting many regions. These included the intracranial dura mater, the spinal cord, the retroperitoneum, the pericardium, and the mediastinum. This disorder is basically similar to systemic Weber-Christian disease except for the absence of subcutaneous panniculitis. Immunohistochemical study reveals that this clinical entity is different from histiocytosis X because the origin of the foamy cells is not the T-zone histiocyte but the macrophage. The treatment of this disease is also discussed.

Adult↗
PubMed1991

[A successful surgical repair of bilateral atrioventricular valve regurgitation in corrected transposition of the great arteries].

The patient was a 52-year-old female with bilateral atrioventricular valve regurgitation, who had SLL-type corrected transposition of the great arteries (C-TGA) accompanied by atrial fibrillation and ventricular extrasystoles (Lown 4b). In performing C-TGA in a patient at such an age, the ability of the anatomical right ventricle to maintain the systemic circulation is reduced, and so it is most important to maintain ventricular function at operation. In this case, we preserved the tricuspid valve and transplanted a biological valve at the tricuspid annulus, while the mitral valve was repaired with Kay's method of annuloplasty. Her postoperative progress was favorable and the echocardiography confirmed that the preserved tricuspid valve did not disturb the motion of the leaflets of the biological prosthesis.

Female↗
PubMed1990

Hormonal regulation of plasminogen activator production by rat hepatocytes in primary culture.

Hormonal regulation in the production of a plasminogen activator (PA) was studied in rat hepatocytes in primary culture. Insulin and epidermal growth factor had no effect on the hepatic PA activity. However, glucagon and epinephrine augmented the activity, whereas dexamethasone suppressed it by lowering the production of hepatic PA rather than by inducing plasmin inhibitors or a plasminogen activator inhibitor (PAI). Dibutyryl cAMP, an analogue of cAMP, also augmented hepatic PA activity. The augmented activity level was lowered by either H-8, cycloheximide, or actinomycin D, suggesting that A-kinase and protein biosynthesis are closely associated with the augmentation. Glucocorticoid and hormones that act to raise the intracellular cAMP level may participate in hepatic PA production by the liver.

Animals↗
PubMed1990

Induction of a variety of tumors by c-erbB2 and clonal nature of lymphomas even with the mutated gene (Val659----Glu659).

The c-erbB2 gene is expressed uniquely in fetal epithelium in vivo and has been suggested to contribute to the development and/or progression of adenocarcinomas in man. In order to assess the oncogenicity of the c-erbB2 gene in vivo, normal c-erbB2 and mutant c-erbB2 encoding glutamic acid instead of valine at position 659 within the transmembrane domain were introduced into mice under the transcriptional regulatory unit of mouse mammary tumor virus long terminal repeat (MMTV-LTR) or immunoglobulin enhancer--SV40 early gene promoter (Ig/Tp). In transgenic mice with normal c-erbB2 under MMTV-LTR, not only adenocarcinomas but also a variety of tumors including B lymphomas were induced at relatively late onset. Induction of pre-B cell lymphomas with normal c-erbB2 was also observed using the Ig/Tp regulatory unit within 6-10 months in some members of one transgenic family among seven lines established. In contrast, with the mutant c-erbB2 under the Ig/Tp regulatory unit, the lymphoma was induced neonatally in all members of four transgenic families among ten lines obtained. However, the immunoglobulin heavy chain gene rearrangement pattern indicated that even with the mutant c-erbB2 the induced lymphomas were clonal.

Adenocarcinoma↗
PubMed1990

Healing of acetic acid-induced gastric ulcer and gastric mucosal PGI2 level in rats.

The present study was designed to investigate the changes in gastric mucosal PGI2 level accompanying the healing of acetic acid-induced gastric ulcers in rats. The ulcers, which were observed with an endoscope, were found to undergo periods of decrease, healing and exacerbation during the rat's lifetime. The phases were categorized as follows: (1) the reduction period (days 3-50 after ulcer induction, corresponding to 7-14 weeks of age), (2) healing period (days 35-150 after ulcer induction, corresponding to 12-29 weeks of age), (3) first exacerbation period (days 35-231 after ulcer induction, corresponding to 12-40 weeks of age), (4) inactive period (days 231-365 after ulcer induction, corresponding to 40-60 weeks of age), and (5) second exacerbation period (days 365-550 after ulcer induction, corresponding to 60-86 weeks of age). In normal rats, the level of gastric mucosal PGI2 gradually increased with aging between 7 and 20 weeks, then decreased up to 40 weeks. The PGI2 level in the 60-week-old rat did not differ from that in the 40-week-old rat. The PGI2 level was the lowest in the 86-week-old rat. In ulcer-bearing rats, the PGI2 level showed the same pattern of change as that in normal rats, but the level was higher. The above results indicated a marked decrease in PGI2 level between 20 and 40 weeks of age and between 60 and 86 weeks of age in normal and ulcer-bearing rats. These periods corresponded closely to the first and second exacerbation periods, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetates↗
PubMed1990

Effects of famotidine and cimetidine on plasma levels of epidurally administered lignocaine.

The effects of two H2-receptor antagonists, famotidine and cimetidine, on the plasma levels of epidurally administered lignocaine were studied. Group A (n = 20) received famotidine 20 mg orally the night before surgery and 20 mg intramuscularly 60 minutes before induction of anaesthesia. Group B (n = 15) received cimetidine 200 mg orally the night before the surgery and 400 mg orally 60 minutes before the anaesthetic induction. Group C (n = 20) received neither famotidine nor cimetidine and served as controls. Twelve millilitres of 2.0% lignocaine with adrenaline 1:200,000 was injected into the epidural space in all patients, after the establishment of general anaesthesia with nitrous oxide, oxygen, and enflurane (0.3-0.5%). The patients who received cimetidine showed significantly higher plasma concentrations of lignocaine compared with either group A or group C at all investigation times (p less than 0.01). The mean peak plasma concentrations were 2.4 (SEM 0.1), 3.2 (SEM 0.2) and 2.3 (SEM 0.1) micrograms/ml in group A, B, and C, respectively. This study suggests that famotidine is preferable to cimetidine for control of gastric acidity before the use of lignocaine as the epidural anaesthetic.

Anesthesia, Epidural↗
PubMed1990

A morphological study of the efferent ducts of the human epididymis.

Efferent ducts of the human epididymis were studied with a light microscope and a computerized three-dimensional image analyser by preparing complete serial sections. The efferent ducts were characterized by a columnar epithelium, which differed both from the cuboidal epithelium of the rete testis and from the tall columnar epithelium of the epididymal duct. Therefore, the junctions of the efferent ducts with the rete testis and epididymal duct could be identified morphologically. Five or six efferent ducts originated from the dilated extra-testicular rete testis, ran in an extremely tortuous manner and transformed into the epididymal ducts in an end-to-end pattern near the border of the epididymal head and corpus. Computerized image analysis confirmed light microscopical findings and demonstrated three-dimensional structures of the junctions of the efferent ducts with both the rete testis and the epididymal ducts.

Aged↗
PubMed1990

Characteristics of aztreonam as a substrate, inhibitor and inducer for beta-lactamases.

Aztreonam was investigated as to its characteristics as a substrate, inhibitor and inducer for the well-defined beta-lactamases of Gram-negative bacteria, and its antibacterial efficacy as to bacterial cells producing eight types of beta-lactamases was also evaluated. Aztreonam was hydrolyzed at measurable rates by class A beta-lactamases, a TEM-2 type penicillinase and the Proteus vulgaris cephalosporinase with a broad substrate range. However, the affinity of aztreonam for the class A enzymes was low, this property being well reflected by its high antibacterial activity toward producers of class A beta-lactamases. Aztreonam was extremely stable as to the typical class C cephalosporinase of Citrobacter freundii, and acted as a competitive and progressive inhibitor for the beta-lactamase. While the MICs of aztreonam in the cases of the constitutive producers of class C beta-lactamases were evidently affected by enzyme production. An experiment involving aztreonam as a inhibitor in combination with a hydrolyzable beta-lactam gave ambiguous results, however, a strong synergistic effect was found in combination with mecillinam. Using Pseudomonas aeruginosa, aztreonam was confirmed to be a poor inducer of beta-lactamases.

Amdinocillin↗
PubMed1990

[Dental management of the medically compromised patient. A study of 162 cases].

Dental management of 162 cases of medically compromised patients was reviewed. Over the past 3 years and 2 months, 130 patients with certain medical problems underwent 162 cases of dental treatment under local anesthesia. In the present study, research was done chiefly on intraoperative management of these patients. The following results were obtained: 1) In the population of 130 patients, those in their 7th decade were the most numerous. Among the subjects, essential hypertension was the most common underlying disease, and the majority of the patients had accompanying cardio-vascular diseases. 2) When the pre- and post-65-year-old patient groups were compared, the latter group had a higher frequency of multiple medical problems. 3) It is suggested that, to manage patients having hypertension or ischemic heart diseases as a complication, continuous blood pressure measurement and ECG monitoring are essential. 4) Among several local anesthetics, 3% prilocaine with 0.03 U/ml felypressin was used most frequently, especially for those with cardiovascular diseases. 5) In the management of hypertensive and ischemic heart patients, nitrous oxide inhalation sedation was effective. 6) For those who required vasodilation, administration of nifedipine or nitroglycerin was effective. 7) Although one case of syncope and another in which dental treatment procedure had to be suspended were found, no severe complications were encountered.

Aged↗
PubMed1990

Karyometric and DNA content analyses of cancer cells in stage III breast cancer with reference to prognosis.

Karyometric and DNA content analyses were simultaneously performed on 32 cases of stage III invasive ductal breast cancer using an image analysis system. From the karyometric analysis, the nuclear areas (NAs; microns 2) were (mean +/- SD) 36.27 +/- 9.40 in five-year survivors (n 17) and 57.14 +/- 13.26 in non-survivors (n 15). The nuclear shape factors (NSFs; NSF = 4 pi X NA/NP2; NP, nuclear perimeter) were 0.756 +/- 0.037 in survivors and 0.716 +/- 0.040 in non-survivors. The NA was significantly larger (P less than 0.01) and the NSF significantly lower (P less than 0.01) in non-survivors than in survivors. From the DNA content analysis, the DNA content values (c; see Measurements section) were +/- 2.59 +/- 0.70 in survivors and 3.72 +/- 1.08 in non-survivors. The percentages of aneuploid cells over 4c were 7.10 +/- 9.89 in survivors and 23.07 +/- 20.19 in non-survivors. The DNA content and the percentage of aneuploid cells over 4c were significantly higher (P less than 0.01) in non-survivors than in survivors. This method may be valuable for estimating the prognosis of patients with invasive ductal carcinoma of the breast.

Adult↗