Search PubMed⌕ Search

Biomedical subjects

M Okamoto

Publications and source records attributed to M Okamoto.

At least 613 records · Page 34Linked to original sources
PubMed1993

Malignant tumors of the head and neck in young patients.

Ten patients under 20 years of age, with malignant tumors of the head and neck was treated at the Department of Otorhinolaryngology of Kitasato University Hospital from August 1971 to December 1989. The primary lesions were situated in the nose and paranasal sinuses in 3, middle ear in 2, epipharynx in 2, and parapharynx, esophagus, and neck in 1 patient. Histological examination indicated 3 rhabdomyosarcomas, 2 malignant lymphomas, and 1 each of neuroblastoma, malignant neuroendocrine tumor, transitional cell carcinoma, lymphepithelioma, and squamous cell carcinoma. The sites of origin and histopathology of malignant tumors in such patients usually differ from those in adults. Well differentiated squamous cell carcinoma of head and neck is common in adults but not in children, in whom non-epithelial malignant tumors or sarcomas are not rare. Radiotherapy is more effective for treating malignant tumors of the head and neck in young than in adults. Eight of 10 patients are still alive, 7 of whom for 5 years or more. Two with rhabdomyosarcoma died.

Adolescent↗
PubMed1993

No allelic loss at the p53 locus in 1,2-dimethylhydrazine-induced mouse colon tumours: PCR-SSCP analysis with sequence-tagged microsatellite site primers.

We examined allelic loss in colon tumors induced by 1,2-dimethylhydrazine (DMH) in F1 hybrid mice, using sequence-tagged microsatellite site (STMS) primers derived from the chromosomal region closely linked to the p53 locus. Polymerase chain reaction--single-strand conformation polymorphism (PCR-SSCP) analysis of 155 colonic tumors with two STMS markers revealed that no genetic alterations had occurred in these tumors, except for one case where one of the markers detected an increase of one CA repeat unit in one allele. No allelic loss at the loci closely linked to the p53 locus strongly suggests that allelic loss at the p53 locus is not involved in DMH-induced colon carcinogenesis in mice.

1,2-Dimethylhydrazine↗
PubMed1993

Three forms of rat CYP11B genes: 11 beta-hydroxylase gene, aldosterone synthase gene, and a novel gene.

We isolated three genomic clones of rat P-450(11 beta) genes (CYP11B). Two of them corresponded to 11 beta-hydroxylase gene (CYP11B1) and aldosterone synthase gene (CYP11B2), respectively. The third one was a novel gene resembling both CYP11B1 and CYP11B2, and was named CYP11B3 gene (CYP11B3). CYP11B2 and CYP11B3 are located tandemly in the genome in the same direction approximately 24 kb apart. These three genes were highly homologous in their amino acid coding regions, with 88% (CYP11B1 to CYP11B2), 89% (CYP11B2 to CYP11B3), 96% (CYP11B1 to CYP11B3) nucleotide identity. The numbers and the locations of the exons of these three genes also exactly corresponded to each other. However, the nucleotide sequences of the 5' upstream regions of CYP11B1 and CYP11B2 were significantly different, suggesting different transcriptional regulations. CYP11B3 had almost the same sequence as CYP11B1 gene in the 5' upstream region. A putative Ad4 site, a cis-acting element present in the promoter regions of all the steroidogenic P-450s so far reported [Morohashi, K., Honda, S., Inomata, Y., Handa, H., Omura, T. (1992) J. Biol. Chem. 267, 17913-17919], was found in the promoter regions of both CYP11B1 and CYP11B2. Gel retardation analysis showed the binding of Ad4BP purified from bovine adrenal cortex to these two Ad4 sites. We analyzed the relative abundance of the mRNAs corresponding to these three genes by the generation of RT-PCR libraries from rat adrenal total RNAs.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1993

A long-term suppression by alpha-interferon of Philadelphia chromosome in children with chronic myelogenous leukemia.

An 8 year old girl with adult type Philadelphia (Ph1)-positive chronic myelogenous leukemia received natural alpha-interferon therapy in the chronic phase. Complete suppression of the Ph1 clone of bone marrow cells was achieved after 1 month of therapy, which was determined by disappearance of rearranged breakpoint cluster region (BCR) gene in Southern blot analysis. Complete hematological remission was also attained following 2 months of therapy. Both the suppression and the hematological remission have been sustained for 24 months with alpha-interferon, in spite of the detection of the chimeric BCR/ABL mRNA in her bone marrow by polymerase chain reaction assay 12 months after therapy.

Amino Acid Sequence↗
PubMed1993

Early afterdepolarizations in a patient with idiopathic monomorphic right ventricular tachycardia.

To identify the role of afterdepolarizations in the induction of idiopathic monomorphic right ventricular tachycardia (VT), monophasic action potentials (MAPs) were recorded in a patient with this type of VT. The VT had a left bundle branch block configuration and inferior axis, and originated in the right ventricular outflow tract (RVOT). MAPs were recorded with a contact electrode at the origin of the VT, as well as other ventricular sites. The VT was induced by the intravenous administration of isoproterenol and/or rapid ventricular pacing and was preceded by short-long-short sequences of RR intervals. Early afterdepolarizations (EADs) in MAPs were recorded at the origin of VT (RVOT), but not recorded at other ventricular sites. These data suggest that catecholamine sensitive triggered activity seems to be the mechanism of idiopathic monomorphic right VT and EADs can be recorded in association with the occurrence of this type of VT.

Action Potentials↗
PubMed1993

An anti-CD3 monoclonal antibody protects mice against a lethal infection with Listeria monocytogenes through induction of endogenous cytokines.

Mice were protected against a lethal infection with Listeria monocytogenes when treated with low doses of an anti-CD3 monoclonal antibody (MAb). Injection of anti-CD3 MAb induced rapid production of endogenous tumor necrosis factor (TNF) in the spleens and endogenous gamma interferon (IFN-gamma) in the bloodstreams and spleens of mice. Administration of anti-Thy1.2 MAb or a combination of anti-CD4 MAb and anti-CD8 MAb resulted in suppression of anti-CD3 MAb-induced endogenous cytokine production and antilisterial resistance. Alternatively, in vivo depletion of anti-CD3 MAb-induced TNF and IFN-gamma by the simultaneous administration of antibodies against TNF and IFN-gamma suppressed anti-CD3 MAb-induced antilisterial resistance. Moreover, injection of anti-complement receptor type 3 (Mac-1, CD11b) resulted in inhibition of anti-CD3 MAb-induced antilisterial resistance. These results suggest that the preventive effect of anti-CD3 MAb might be due to activation of phagocytes by TNF and IFN-gamma induced by stimulating CD4+ T cells and CD8+ T cells with the MAb. Furthermore, treatment with anti-CD3 MAb did not inhibit establishment of acquired resistance against secondary infection with L. monocytogenes.

Animals↗
PubMed1993

Changes in diaphragmatic EMG activity during sleep in space.

It remains unknown how increased upper airway resistance (UAR) during sleep could be a function of gravity. We therefore conducted quantitative evaluation of the gravitational influence on diaphragmatic EMG activity (EMGdi) in an astronaut to estimate the effect of UAR in space. EMGdi was recorded by paired surface electrodes on the ground (control, C) and abroad a short-term space mission (space, S) for 30 consecutive h. Mean EMGdi recorded during quiet breathing in wakefulness was assigned the value of 100. EMGdi in C was significantly enhanced in all sleep stages compared with that while awake in the supine position (mean +/- SD, 230 +/- 23.2% in non-rapid eye movement (non-REM) Stage II, 233 +/- 13.8 in slow-wave sleep, and 233 +/- 40.0 in REM sleep versus 100 +/- 17.3 in wakefulness, p < 0.001). In contrast, there was no statistical difference in EMGdi in S between awake and any non-REM sleep stage (mean +/- SD, 100 +/- 20.5% in wakefulness versus 103 +/- 16.9 in non-REM Stage II and 100 +/- 14.8 in slow-wave sleep; NS). However, EMGdi in REM sleep in S was statistically greater (132 +/- 28.3%) than that during wakefulness or any other sleep stage in space (p < 0.001). Therefore, gravity may play a much more significant role in the normal healthy human in the increased upper airway resistance during sleep than the relative atonia of the upper airway muscles.

Analysis of Variance↗
PubMed1993

[Preparation of phenylpropylsilica and its application to high performance liquid chromatographic analysis of proscillaridin].

Proscillaridin in commercial tablet preparations was analyzed by HPLC on a phenylpropyl chemically bonded stationary phase, prepared by treating porous silica with phenylpropyldimethylchlorosilane (PHP). From the elemental analysis data for carbon, the number of bonded PHP surface groups per 1 nm2 of silica (mean pore diameter 13.1 nm, specific surface area 330 m2/g, mean particle size 5.5 microns) in PHP gel was calculated to be 2.07. Using methanol-distilled water (80:20, v/v) as an eluent, the separation of proscillaridin was successfully performed on the PHP column.

Chromatography, High Pressure Liquid↗
PubMed1993

Long-term results of catheter ablation for idiopathic ventricular tachycardia originated from the right ventricular outflow.

We performed catheter ablation in 10 consecutive patients with idiopathic monomorphic right ventricular tachycardia and studied the long-term outcome. All ventricular tachycardias had a left bundle branch block configuration with an inferior axis, and originated from right ventricular outflow. Antiarrhythmic drugs (3-6 drugs) had been ineffective in controlling ventricular tachycardia. The 2 patients who underwent direct-current ablation (2 shocks of 150 J) had no recurrence of ventricular tachycardia and did not require antiarrhythmic drugs during a follow-up of 56 and 51 months, respectively. Of the 8 patients who underwent radiofrequency ablation (30-40 watt, 20-40 sec, 2-15 application, using Inter Nova RA 50, 13.56 MHz), 1 patient had no recurrence of ventricular tachycardias and did not require antiarrhythmic drugs, 4 patients had no recurrence of ventricular tachycardias but did require anti-arrhythmic drugs, and 3 patients experienced recurrence of non-sustained ventricular tachycardia despite the use of antiarrhythmic drugs during a follow-up of 15-40 months. There were no complications except for cardiac perforation which occurred immediately after direct-current ablation in 1 patient. In conclusion, long-term success in preventing ventricular tachycardia was achievable with direct-current ablation, but this success was associated with serious risks, such as cardiac perforation. Radiofrequency ablation was safer than direct-current ablation, but had a lower long-term success rate.

Adult↗
PubMed1993

[Invention of an air forced ventilated micro-isolation cage and rack system--environment within the cages: ventilation, air flow].

A forced air ventilation system for small laboratory animals was developed. The system consists of an air handling unit with air supply and exhaust fans, a rack, hard cage covers with a large diameter air inlet and an outlet, and shoe box cages. Air flow from the supply duct, to the exhaust duct and within the cage were observed. Variations in air flow among cages was minimal. The optimal air exchange rate of the cages in this system was determined to be 60 times per hour based on the results obtained in the present study. At this air exchange rate, air flow at the base of the cages had a velocity of less than 0.09m/sec, which was within the range of recommended values for humans. The observed results show that the system developed is capable of sustaining a laboratory animal microenvironment well in terms of air flow, without too much energy cost.

Air Movements↗
PubMed1993

Delayed-type skin allergic reaction in guinea pigs induced by anti-rheumatic compounds with sulfhydryl groups.

Delayed-type skin allergic (DTA) reactions induced by various sulfhydryl compounds were investigated. Sulfhydryl compounds investigated were bucillamine and D-penicillamine: antirheumatic agents, SA981: an intramolecular cyclic disulfide of bucillamine, tiopronin: a hepatoprotective and potent antirheumatic agent and captopril: antihypertensive and potent antirheumatic agent. Guinea pigs were sensitized on day 1 by subcutaneous injection and day 7 by subcutaneous and intramuscular injection of emulsions of these compounds (3 mg/animal) with Freund's complete adjuvant. Two weeks after the second sensitization, 0.3 mg/animal of each compound was intradermally challenged and the 24 hr DTA reaction was evaluated. A large number of sulfhydril compounds showed positive in the DTA reactions and the intensity of these reactions had a good correlation with the frequency of the skin rashes referred to by the adverse effects in clinical reports of anti-rheumatic drugs. It is suggested that guinea pig DTA reaction may provide a good screening way to find new sulfhydryl or disulfide compounds with low incidence of skin rash. A novel sulfhydryl compound N-(2,2-dimethyl-3-mercaptopropionyl)-L-cysteine (SA3441) and its intramolecular cyclic disulfide (4R)-hexahydro-7,7-dimethyl-6-oxo-1,2,5-dithiazocine-4-carboxylic acid (SA3443), which show no DTA activity in guinea pigs, were found using the above-mentioned DTA reaction.

Animals↗
PubMed1993

[Cholesteatoma in children--sex differences].

It has been reported that cholesteatoma is more aggressive in children than in adults and that it affects boys more often than girls. We found particularly prominent sex differences in the clinical characteristics and behavior of cholesteatoma in children, by comparing them with those of acute otitis media (AOM), otitis media with effusion (OME) and adult cholesteatoma. We retrospectively analyzed the clinical records of children diagnosed as having cholesteatoma by comparing their courses with those of AOM, OME, chronic otitis media, microtia and congenital malformation of the ossicles. The boy-dominant tendency were observed in OMA, OME, pediatric cholesteatoma, microtia and congenital malformation of the ossicles. Cholesteatoma has a tendency to fill the middle ear cleft in boys, in whom the most extensive cholesteatomas were observed. If OMA, OME, and cholesteatoma in children are considered to be a series of inflammatory middle ear diseases, a common factor must be involved in the boy-dominant tendency for this series of inflammatory middle ear diseases. We have proposed six factors contributing to sex differences in pediatric cholesteatoma. Among these, immunological, environmental and congenital factors were thought to be responsible for the sex differences.

Acute Disease↗
PubMed1993

[Carcinoma of the nasopharynx: analysis of treatment results in 51 patients].

The outcomes of 51 cases of nasopharyngeal carcinoma, treated in our hospital between July 1971 and June 1991, were evaluated. Factors which appeared to influence prognosis were assessed by the Kaplan-Meier method. The ages of the patients ranged from 18 to 74 years. There were 38 males and 13 females. The cumulative five-year survival rate for the whole study population was 60.6%. The UICC classification (1987) was used for disease staging. The percentages of patients surviving after five years were: 100% (n = 1) for stage II, 75% (n = 4) for stage III, and 58.1% (n = 46) stage IV. The histological type with the highest survival rate was poorly differentiated squamous cell carcinoma, which had a 69.8% (n = 37) survival rate. The anatomical sites of primary tumors were the lateral wall (62.4%, n = 33) and the posterior wall (54%, n = 33). Percentages of patients according to classification based on initial therapy were as follows: Combined radiotherapy and chemotherapy group, 61.5% (n = 22); radiotherapy alone group, 56.5% (n = 22). The incidences of local recurrence according to initial therapy were 36% in the combined therapy group and 50% for the radiotherapy alone group. There were no metastases to the cervical lymph nodes after initial therapy in stage II and III. In stage IV, the rate of metastasis was lower when combined therapy was given. When the relationship between initial therapy and distant metastasis was evaluated, the rate of metastasis was lower in the combined therapy group. We conclude that combined therapy is necessary in the treatment of nasopharyngeal carcinoma.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

[The effects of concomitant pictorial information on the memory and comprehension of story].

The present study was carried out to examine the effect of movement and coloring of concomitant pictures on children's story learning. The story was Hans Christian Andersen's HINAGIKU (daisy), which was 47 sentences long. In relation to the story, the subjects in experimental groups were presented the static or moving pictures by means of picture-card show or animation video. Those pictures were colored or uncolored. Immediately after the story learning, the subjects were given verbative recall and inferential tests. The 156 second graders were assigned to one of four experimental groups and a control group (without pictures). The main findings were as follows; (1) The coloring of picture had facilitative effects on the verbative recall of story. This result indicates that clear visual imagery improved the memory of story. (2) The moving of picture facilitated the inferential test performance. This result indicates that the movement of picture clarified the story context and gave a lot of cue information to comprehend story.

Child↗
PubMed1993

FR901277, a novel inhibitor of human leukocyte elastase from Streptomyces resistomycificus. Producing organism, fermentation, isolation, physico-chemical and biological properties.

A novel human leukocyte elastase inhibitor, FR901277 was discovered in the fermentation broth of Streptomyces resistomycificus No. 7622. FR901277 has a molecular weight of 961 and a molecular formula of C47H63N9O13. The mode of inhibition is competitive, with a Ki of 1.2 x 10(-8) M. Oral administration of FR901277 at doses from 32 to 320 mg/kg significantly prevented human leukocyte elastase-induced foot edema in mice.

Animals↗
PubMed1993

[Clinicopathological evaluation of high-range hyperthermia for advanced thoracic esophageal carcinoma].

The effectiveness of high-range hyperthermia over 45 degrees C for advanced esophageal carcinoma was clinicopathologically evaluated. Fifty-eight patients with advanced thoracic esophageal carcinoma were treated with radio-chemotherapy. They were divided into two groups: group I included 32 cases, all of whom received hyperthermia (13 cases: high-range hyperthermia); group II included the other 26 cases. The patients were given 2 Gy/day for a total of 15 sessions in 3 weeks. Bleomycin and cisplatin in combination with 5-fluorouracil have been employed as chemotherapy. Hyperthermia was performed twice a week for a total of 6 sessions. Intraluminal heating was done using Japan Crescent Inc. IH-500 T (RF, 13.56 MHz), with an intraesophageal applicator and two extra-corporeal applicators on the chest and the back. Concerning local effects, the efficacy rate was 81.3% in group I (high-range: 92.9%), and 42.3% in group II. The histologic effectiveness, when Grade 2 and 3 are determined as histologically effective, were 64.3% (high range: 85.7%) and 50.0% in group I and II, respectively.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1993

[Neoadjuvant chemotherapy effective for small cell lung cancer in a nephrectomized patient].

A 67-year-old man, who was nephrectomized due to renal cell cancer 4 years ago, was admitted to examine a mass shadow in the right middle lung field. He was diagnosed as small cell lung cancer with TBLB. Because of impaired renal function, he was treated with CBDCA (300 mg/m2, day 1), THP (30 mg/m2, day 1) and oral etoposide (25 mg/body, for 21 days) without any renal complications. After 3 courses of chemotherapy, the lung CT showed scar lesion despite the disappearance on the chest X-ray, and a right lower lobectomy was performed. Malignant cells remained in the scar lesion, but not in the lymph nodes. These findings suggested the effectiveness of neoadjuvant chemotherapy. This newly-designed chemotherapy procedure is necessary for patients with renal complications.

Aged↗