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Biomedical subjects

M Iwata

Publications and source records attributed to M Iwata.

At least 19 recordsLinked to original sources
PubMed1992

Retinoic acids inhibit activation-induced apoptosis in T cell hybridomas and thymocytes.

Apoptosis is induced in immature thymocytes and T cell hybridomas upon stimulation via the TCR/CD3 complex. This phenomenon appears to be related to negative selection of T cell clones in the thymus. In T cell hybridomas, it has been shown that glucocorticoids inhibit TCR/CD3-mediated apoptosis, whereas glucocorticoids alone induce apoptosis. All-trans-retinoic acid (RA) at 0.1 to 10 microM also inhibited TCR/CD3-mediated apoptosis assessed by DNA fragmentation and cytolysis, but RA alone hardly induced apoptosis. RA enhanced the effects of glucocorticoids to induce apoptosis and to inhibit TCR/CD3-mediated apoptosis. TCR/CD3-mediated stimulation can be mimicked by the combination of ionomycin, a calcium ionophore, and PMA, an activator of protein kinase C, and the combination-induced DNA fragmentation was also inhibited by RA. RA, however, failed to inhibit the combination-induced increase in intracellular Ca2+ concentration or the combination-induced translocation of protein kinase C from the cytosolic fraction to the particulate fraction. Time course studies of RA addition into the culture indicated that a 3- to 6-h delay in the addition of RA did not reduce its inhibitory effect on anti-CD3-induced DNA fragmentation. These results suggest that RA interferes with the apoptotic process at some point after its initiation stage. It has been suggested that negative selection involves not only TCR/CD3-mediated signals but also LFA-1-mediated signals. RA at 0.01 to 1 microM significantly inhibited the induction of thymocyte apoptosis by co-immobilized mAb to CD3 and LFA-1 molecules. RA by itself hardly induced apoptosis, but enhanced glucocorticoid-induced apoptosis. The results suggest that thymic selection might be influenced by RA at near-physiologic concentrations. The receptors of glucocorticoids and RA belong to the erbA oncogene-related steroid hormone receptor superfamily. Thyroid hormones and 1 alpha,25-dihydroxy vitamin D3, whose receptors also belong to the superfamily, failed to modulate apoptosis in both T cell hybridomas and thymocytes.

Animals↗
PubMed1992

Determination of diphenylmethane antihistaminic drugs and their analogues in body fluids by gas chromatography with surface ionization detection.

Eleven diphenylmethane antihistaminic drugs and their analogues were tested for their detection by capillary gas chromatography (GC) with surface ionization detection (SID). The GC-SID response was highest for doxylamine, diphenhydramine and orphenadrine and lowest for terodiline, clemastine and pipethanate. The detection limits for drugs with the highest response were 2-5 pg (ca. 6-20 fmol) on-column (100-250 pg/ml of body fluid). The detection limits with GC-SID were 10-100 times higher than those with GC with nitrogen-phosphorus detection. A detailed procedure for the isolation of the antihistaminics from human whole blood and urine by the use of Sep-Pak C18 cartridges, prior to GC-SID, is also presented. The recoveries of the drugs (50 or 500 pmol), which had been added to 1 ml of body fluids, were > 60%. The baselines remained steady as the column temperature was increased and the background was clean, especially for whole blood extracts.

Benzhydryl Compounds↗
PubMed1992

Sensitive determination of phenothiazines in body fluids by gas chromatography with surface ionization detection.

Fourteen phenothiazine derivatives were tested for their detection by gas chromatography (GC) with surface ionization detection (SID). The sensitivity of GC-SID was highest with trimeprazine and levomepromazine, which contain aliphatic tertiary amino side chains, and lowest with thiethylperazine and thioproperazine, which contain sulphur residues. Chlorpromazine, trimeprazine and promazine showed excellent linearity between the SID response and the drug amount in the range 0.25-3.0 pmol on-column. Their detection limits were as low as ca. 5-10 pg (15-30 fmol) on-column (250-500 pg per ml of body fluid). A detailed procedure for isolation of phenothiazines from human whole blood and urine using Sep-Pak C18 cartridges, before the GC with SID, is also presented. The recoveries of the drugs (100 pmol), which were added to 1 ml of whole blood or urine, were more than 79%. The baselines remained steady as the column temperature was increased.

Chromatography, Gas↗
PubMed1992

Significance of multidisciplinary therapy for hepatocellular carcinoma.

The effect of multidisciplinary therapy for hepatocellular carcinoma (HCC) was evaluated in 121 resected cases. The 5-year survival was 100% for absolute curative resection (12 cases), 59.1% for relative curative resection (n = 37) and 10.9% for relative non-curative resection (n = 59). However, none of the patients survived for more than 3 years after absolute non-curative resection (n = 13). The non-recurrence in the preoperative TAE groups was different from that in non-TAE groups undergoing absolute and relative curative resection. The 1- and 3-year non-recurrence rates for relative non-curative resection were 92.3% and 53.8%, respectively, for the preoperative TAE group and 56.1% and 28.1%, respectively for the non-TAE group. These data show that preoperative TAE is effective in relative non-curative resection. Functional disturbances of the coagulation-fibrinolysis system in cirrhotic patients were improved after PSE. All patients undergoing hepatectomy after PSE had an uneventful postoperative course, including well-maintained function of the coagulation-fibrinolysis system and a decrease in splenic volume. At 1 year after hepatectomy, cirrhotic patients with critical liver function and poor coagulation-fibrinolysis showed appreciable hepatic regeneration. One patient died of hepatic failure 1 year after the operation. In recurrent HCC, the 1-, 2- and 3-year survival values after reresection were 100%, 75.0% and 25.0%, respectively. The respective values following TAE were 79.0%, 42.0% and 9.0%. Three cases of recurrent HCC were effectively treated, i.e., two patients achieved a partial response and one showed no change, by continuous intra-arterial infusion of 5-FU and lentinan with intermittent one-shot injections of epirubicin using a subcutaneous infusion pump. These three patients are alive at 1 year and 7 months, 1 year and 4 months and 6 months after the treatment, respectively.

Adult↗
PubMed1992

Kanji word reading process analysed by positron emission tomography.

Positron emission tomography, involving the H2(15)O injection technique, was used to study changes in regional cerebral blood flow during Japanese kanji word reading. Three-times intrasubject averaging analysis revealed that the main cortical responses occurred in the bilateral (left-side dominant) posterior inferior temporal area for visual input. We believe the left posterior inferior temporal area processes highly complex morphological features of kanji. For language output, left-side dominant activation of the posterior inferior frontal gyrus and the basal ganglia was found.

Adult↗
PubMed1992

Nation-wide collaborative study on the long-term effects of bromocriptine in the treatment of parkinsonian patients. Final report.

Final results of the 5-year multicentric collaborative study on the long-term effects of bromocriptine in the patients with Parkinson's disease are reported. This prospective study started in May 1985 in order to see whether the early combination therapy with bromocriptine and levodopa is really superior to the levodopa monotherapy with regard to the late side effects of levodopa in the treatment of parkinsonian patients. Another project of the study was to see the therapeutic efficacy of bromocriptine monotherapy without concomitant use of levodopa. For these purposes, a total of 702 patients with Parkinson's disease were enrolled into three groups: Group 1 (n = 286) with bromocriptine monotherapy, Group 2A (n = 216) with early combination of bromocriptine and levodopa, and Group 2B (n = 200) with levodopa alone. At the end of the 5-year study, 48 patients in Group 1 (16.8%) were still continuing bromocriptine monotherapy with satisfactorily good therapeutic effects. About half (49.1%) of the Group 2A patients remained on the combined therapy, and the comparable number of the Group 2B patients (46.0%) were also kept on the initial mode of therapy, while 13.5% of the latter group with levodopa monotherapy needed bromocriptine to be added in order to assure the good therapeutic effects. Moreover, significant differences were seen between group 2A and Group 2B with regard to the incidence of wearing-off phenomenon and dyskinesias. Disappearance rate of dyskinesias which were present at the time of enrollment was significantly higher in Group 2A than in Group 2B. No significant difference was noted as to the incidence of untoward symptoms and the death rate among all three therapeutic groups. These results support the view that the early combination of bromocriptine with levodopa is superior to levodopa alone in the treatment of Parkinson's disease.

Activities of Daily Living↗
PubMed1992

Nation-wide collaborative study on the long-term effects of bromocriptine in the treatment of parkinsonian patients: analysis on the maintenance and the change of the original mode of treatment.

A nation-wide collaborative study to evaluate the long-term effects of bromocriptine in patients with Parkinson's disease was completed as described in the accompanying paper. The present study analysed the same data by paying attention to a group of patients who maintained the original mode of therapy and to a group of patients who changed the mode of treatment by adding levodopa or bromocriptine to the original drug. Surprisingly, 48 among 286 patients in a group of bromocriptine monotherapy maintained the original mode of therapy. This group has particular features of a short duration of illness and a low grade of Hoehn-Yahr's scale. It is noteworthy that this group of patients did not show wearing-off phenomenon. The effects of additional bromocriptine to levodopa for a 5-year period were analysed by comparing two groups of combination therapy and levodopa alone therapy maintained for 5 years, with 106 and 92 patients, respectively. Results were essentially the same as those obtained from the accompanying paper, i.e., in general, treatment by combination with bromocriptine may be more suitable than treatment by levodopa alone. In order to find the best timing of the combination of levodopa and bromocriptine, results of 3 groups were compared, i.e. a group of patients who started with bromocriptine alone and later added with levodopa (82 patients), a group of patients who maintained the combination for 5 years (106 patients) and a group of patients who started with levodopa alone and later added bromocriptine (27 patients). The best results were obtained in the group of 5-year combination.(ABSTRACT TRUNCATED AT 250 WORDS)

Activities of Daily Living↗
PubMed1992

Accumulation of cis-diamminedichloroplatinum (II) and its analogues in sensitive and resistant human ovarian carcinoma cells.

Human ovarian carcinoma cell line (NOS2), established from a patient with serous cystadenocarcinoma of the ovary, has been exposed to a stepwise increase in cis-diamminedichloroplatinum (II) (CDDP) concentration to produce a CDDP-resistant cell line NOS2CR) as an experimental model for resistance to CDDP. NOS2CR cells showed a 7-fold resistance to CDDP and a lesser degree of cross-resistance to diammine (1,1-cyclobutanedicarboxylato)-platinum (II) (CBDCA) and (-)-(R)-2-aminomethylpyrrolidine (1,1-cyclobutanedicarboxylato) platinum (II) (DWA2114R). In the absence of CDDP, cross-resistance to DWA2114R was reduced to the original level by 2 months, although 83% resistance to CDDP remained up to 6 months. To investigate CDDP-resistant mechanisms, alterations in the intracellular accumulation of CDDP and analogues were assayed by atomic absorption. In both NOS2 and NOS2CR cells, accumulation of CDDP increased linearly with time and was concentration-dependent. NOS2CR cells demonstrated 71, 52 and 12% reduction in accumulation of CDDP, CBDCA, and DWA2114R, respectively. These reductions did not seem to be due to P-glycoprotein, because expression of multidrug-resistant 1 gene was not detected in either NOS2 or NOS2CR cells. These studies indicate that the mechanisms of resistance to CDDP and analogues in NOS2CR cells are related in the main to reduced intracellular accumulation of drugs. DWA2114R might be helpful to treat CDDP-resistant and recurrent tumors which were treated by CDDP.

Antineoplastic Agents↗
PubMed1992

Study of bronchus-associated lymphoid tissue in patients with diffuse panbronchiolitis.

Bronchus-associated lymphoid tissue (BALT) is thought to affect local immunologic defense mechanisms. Studies of BALT, however, have mainly been focused on animals, and information detailing the BALT structure and functions in humans is scanty. Therefore, the purpose of this study is to clarify BALT morphology and immunologic findings in patients with diffuse panbronchiolitis (DPB) and compare them with BALT findings in animals. Thus, in 17 patients diagnosed with DPB, open-lung biopsy specimens were reviewed, and lymphoid follicles with a lymphoepithelium that was determined as BALT were identified in 12 patients. BALT was found mostly at bifurcations from nonrespiratory bronchioles to respiratory bronchioles. This lymphoepithelium was devoid of cilia and was diffusely infiltrated with CD4-positive (helper/inducer) T cells. The majority of T cells were confined to the parafollicular area with a predominance of helper T cells. Also, a few high endothelial venules were recognized in the parafollicular area. Further, in a follicular area situated in the center of the BALT, a number of sigM-positive cells were found to be heavily distributed, suggesting that this follicular area has the characteristics of a B cell zone equivalent to a germinal center of the peripheral lymph nodes. These observations are comparable with BALT findings in animals and suggest that BALT is at least partially related to the local immune response.

Adult↗
PubMed1992

Japanese crossed Wernicke's aphasia.

A right-handed Japanese man with no personal or family history of left-handedness developed severe Wernicke's aphasia, a mild constructional disorder, and slight left hemiparesis. MRI revealed infarction in the territory of the righ middle cerebral artery, including areas homologous to Broca's and Wernicke's areas. The cerebral blood flow in these areas remained diminished even after language activation. The most likely explanation is that language production occurred in the left Broca's area, while language comprehension occurred in the right Wernicke's area (a dissociated aphasia).

Aphasia, Wernicke↗
PubMed1992

The influence of chloro-substituent sites of hexachlorobiphenyl on the respiration of rat liver mitochondria.

The actions of three hexachlorobiphenyls (HCBs) 2,3,4,2',3',4'-, 2,3,4,3',4',5'- and 3,4,5,3',4',5'-HCBs, on the respiration of rat liver mitochondria with succinate as the substrate were compared, and the effect of chloro-substitution sites in HCB on the respiration was examined. 2,3,4,2',3',4'-HCB strongly inhibited both state 3 and 2,4-dinitrophenol (DNP)-stimulated respiration with 50% inhibition dose of 52 and 54 microM for state 3 and DNP-stimulated respiration, respectively. The inhibitory action of 2,3,4,3',4',5'-HCB on both respiration was approximately half as potent as that of 2,3,4,2',3',4'-HCB. On the other hand, 3,4,5,3',4',5'-HCB did not inhibit any respiration at all. These results indicate that both inside (ortho) and outside (meta or para) positions in each phenyl ring of the biphenyl molecule should be replaced with chlorines for HCB to be an effective inhibitor. Either the actual position of chloro-substituent or steric conformation caused by its substitution or both can be considered as factors affecting the inhibition. On the basis of the conformational energy, calculated by AM1 (Austin model 1) method, with increases in chlorine number in ortho position, HCB molecule became angulated. Furthermore, calculated probability of the conformation distribution for HCB indicated that the probability of nonplanarity was higher for effective HCB than for less effective HCB. These structural features suggest the significance of steric conformation as well as chloro-substituent sites in determining the inhibitory ability of HCB.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

[A case of eosinophilic pneumonia with diffuse reticular shadows and scattered nodular shadows on chest X-ray film--comparison of findings of chest X-ray and lung histology].

A 47-year-old woman was admitted to our hospital because of dry cough and throat discomfort. Chest X-ray film showed reticular shadows with Kerley B line and scattered nodular shadows. Blood examination revealed normal WBC count (5100/mm3) with eosinophilia (21%), negative CRP, elevated ESR (49 mm/l hr), normal IgE level and positive antinuclear antibody with speckled pattern. Skin tests and precipitating antibodies for common allergens were negative. Results of arterial blood gas analysis and respiratory function test were almost normal. Bronchoalveolar lavage fluid yields 85.7% eosinophils, which suggested eosinophilic lung disease. To establish the diagnosis, thoracotomy was performed and lung specimens were obtained from S3a and S8a. In the area of the nodule, the alveolar spaces were filled with eosinophils and mononuclear cells, with no evidence of vasculitis, granuloma or parasites. Alveolar spaces were almost preserved in residual areas. The walls of air ways, pleura and lobular septa were heavily infiltrated with eosinophils and mononuclear cells. Thus, open lung biopsy confirmed the diagnosis of idiopathic eosinophilic pneumonia. The areas of intraalveolar filling with eosinophils and mononuclear cells were found to correspond to the nodular shadows on chest X-ray film. The relationship between the findings of chest X-ray films and lung histology are discussed.

Female↗
PubMed1992

[Naming difficulties seen in a case of alexia with agraphia caused by a left postero-inferior temporal lesion].

A 71-year-old right-handed man presented writing and reading difficulties as well as naming difficulties. Neuropsychological examinations revealed mild fluent type aphasia accompanied by alexia and agraphia predominantly affecting kanji and also severe naming difficulties. Brain MRI showed cerebral subcortical hemorrhage extending from the anterior one-third of the left temporal lobe to the temporo-occipital junction involving the fusiform gyrus. The analysis of the several reported cases with severe alexia with agraphia for kanji including ours revealed a close correlation between the severity of kanji writing disturbances and that of naming difficulties. It was also shown that cases with severe naming difficulties had lesion extending anteriorly to the anterior middle temporal gyrus or medially to the parahippocampal gyrus, suggesting that the disconnection between the parahippocampal gyrus and other cortices including the temporal lobe was essential for production of naming difficulties.

Aged↗
PubMed1992

[Clinical and laboratory evaluation of pediatric kidney disease].

In infancy, the kidney by itself is immature and the body fluid composition is extremely different from that in adults. Further more, there are various renal diseases in children with characteristics different from those in adults. Thus in childhood, consideration for aging is critical for evaluation of renal function, and diagnosis of the disease. Recently, mass screening for infants or children in kindergarten or school has enabled us to find many children with renal disease, in whom symptoms are not overt. Thus the disease can be treated in an early phase. This may give a better prognosis for such children. To make an early diagnosis of renal disease it is essential to consider what laboratory tests are chosen and how the data accumulated are interpreted. In the present study, individual laboratory tests for the diagnosis of renal diseases and an indication of such tests as well as interpretation of the data are reviewed.

Child↗
PubMed1992

[Case of adult primary varicella pneumonia].

We report a case of adult primary varicella pneumonia. A 34-year-old man was admitted to our hospital with fever, dry cough and eruptions. He had no history of chicken pox and his sons had contracted varicella 2 weeks before the onset of his symptoms. Chest X-ray showed diffuse nodular shadows in both lungs. The diagnosis of primary varicella pneumonia was made based on family history, typical eruptions and high titer of antibody against Varicella zoster virus. An electron micrograph indicated this case to be primary varicella pneumonia with fibrosis and edema of interstitial spaces and the presence of virus-like particles in cells. The patient was treated with antibiotics, an antiviral agent and immunoglobulin. The clinical symptoms and diffuse nodular shadows resolved with this treatment.

Acyclovir↗
PubMed1992

[Concomitant graft replacement of the total aortic root and the transverse aortic arch for type A aortic dissection associated with annuloaortic ectasia].

Between April 1988 and February 1992, eight patients with type A aortic dissection associated with annuloaortic ectasia (AAE) underwent the concomitant graft replacement of the total aortic root and the transverse aortic arch at our institution. The acuity of the aortic dissection was acute stage in 3 patients and chronic stage in 5 including 3 cases of re-do operation. All operations were performed with an aid of extracorporeal circulation, blood cardioplegia, selective cerebral perfusion and open distal anastomosis. The operative techniques employed in this series consisted of total aortic root replacement using a composite graft (Bentall, Cabrol or Piehler's technique), and total arch replacement using en bloc arch reconstruction or three vessels graft replacement. One patients underwent re-do operation for coronary anastomotic false aneurysm following Bentall operation and aneurysmal dilatation of the false lumen at the aortic arch, and died of LOS because of the prolonged myocardial ischemia. Other seven patients survived the operation, and lead the normal life at the present time. The present data suggests that type A aortic dissection associated with AAE involving aortic arch could be treated by concomitant graft replacement of the total aortic root and the transverse aortic arch.

Adult↗
PubMed1992

[Diagnosis of ovarian tumors by transvaginal Doppler ultrasound with color flow imaging].

Ovarian carcinoma is a silent disease with few symptoms. Early detection of ovarian cancer is difficult. Transvaginal Doppler ultrasound with color flow imaging is a new technique in the evaluation of gynecological diseases. This method was used in the diagnosis of ovarian tumors in 39 women who were treated in the Department of Obstetrics and Gynecology, Nagoya University Hospital. Wave forms of the parenchymal tumor arteries or tumor surface arteries were compared by according to the pulsatility index (PI). 1/PI was 0.69 +/- 0.04 in benign tumor and 2.33 +/- 1.36 in malignant tumors (p less than 0.01). When the cutoff value of 1/PI was set at 0.8 (cutoff value of PI: 1.25), the accuracy of diagnosis was 84.6% (33/39). The accuracy of ultrasonographic pattern classification and CA125 were 74.4% (29/39) and 53.8% (21/39), respectively. In 18 tumors with low CA125 (less than 35 U/ml), 5 of 7 malignant tumors (71.4%) had high 1/PI (greater than 0.8), and benign tumor, low 1/PI (less than 0.8) or non-detectable wave forms. This procedure should prove to be useful in the diagnosis of ovarian cancer.

Adult↗