Biomedical subjects

M Iwata

Publications and source records attributed to M Iwata.

At least 379 records · Page 21Linked to original sources

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↗

PubMed1992

[A case of bronchiolitis obliterans organizing pneumonia with positive anti Jo-1 antibody preceding polymyositis].

We describe a 58-year-old female with BOOP associated with polymyositis. Four months prior to the appearance of distinctive manifestation of polymyositis, she presented with a two-week history of cough, dyspnea on exertion, and fever. Chest roentgenogram demonstrated bilateral basal infiltrative shadows. The patient was treated with prednisolone, 30 mg/day because of progressive hypoxemia. Open lung biopsy revealed organizing masses of granulation tissue extending from the respiratory bronchioles into the intra-alveolar spaces, which was consistent with BOOP. She developed muscle pain in her legs, fever, dry cough, hypoxemia, and high CPK value in the course of tapering of steroid dose. The findings of biopsy from the left rectus femoris muscle were compatible with polymyositis. Retrospective study of the patient's serum on admission showed positive anti Jo-1 antibody.

Antibodies, Antinuclear↗

PubMed1992

Regulation of HLA class II antigen expression on cultured corneal epithelium by interferon-gamma.

The effect of recombinant human interferon gamma (IFN-gamma) on the induction of HLA class II (HLA-DR, -DP, -DQ) antigen expression on human corneal epithelial (HCE) cells was examined in different stages of culture. Primary cultures were established with limbal explants without endothelium. HCE cells in Stage 1 and Stage 2, with cells negative and positive for the 64K corneal keratin (the marker for advanced corneal epithelial differentiation), respectively, were prepared. HCE cells in both stages were treated with IFN-gamma at a concentration of 0 to 1000 U/ml for two to six days and were stained by the avidin-biotin peroxidase complex method. Class II antigens were not detected on HCE cells in either stage without IFN-gamma treatment. IFN-gamma induced three class II antigens on HCE cells in both stages in a dose- and time-dependent manner but at different levels for each antigen (DR greater than DP greater than DQ). In addition, DQ expression was related to cell differentiation, with DQ extremely rare at Stage 1 and more frequent at Stage 2 (5% vs. 20%). These findings indicate that the induction of class II antigens on HCE cells may be regulated by IFN-gamma independently for each of the antigens and that DQ induction may depend upon the differentiation of HCE cells in culture.

Cell Differentiation↗

PubMed1991

Regulation of T lymphocyte apoptosis. Signals for the antagonism between activation- and glucocorticoid-induced death.

Apoptotic death can be induced in T cell hybridomas by glucocorticoids or the stimulation via the TCR/CD3 complex. The two apoptotic processes are mutually antagonistic. We have previously proposed that positive selection of thymocytes for the formation of the T cell repertoire might be based on a similar mechanism. We analyzed the TCR/CD3-mediated signals essential for the regulation of apoptosis in T cell hybridomas. We suggest that both an increase in the intracellular Ca2+ level and an activation of protein kinase C are essential for the TCR/CD3-mediated apoptosis, because we obtained the following results: 1) either reduction of extracellular Ca2+ concentration or addition of a protein kinase inhibitor, 1-(5-isoquinolkinelsulfonyl)-2-methylpiperazine or N-(2-(methylamino)ethyl)-5-isoquinolinesulfonamide, inhibited anti-CD3-induced but not dexamethasone-induced DNA fragmentation. 2) The combination of ionomycin and PMA, but neither one alone nor the combination of ionomycin and cyclic nucleotide analogs, induced DNA fragmentation. On the contrary, we suggest that only an increase in the intracellular Ca2+ level is essential for the inhibition of glucocorticoid-induced apoptosis, because ionomycin alone as well as the combination of ionomycin and PMA inhibited dexamethasone- but not anti-CD3-induced DNA fragmentation.

Animals↗

PubMed1991

A large chondroitin sulfate basement membrane-associated proteoglycan exists as a disulfide-stabilized complex of several proteins.

Proteoglycan (PG)-1000 (formerly TAP-1) is a large (Mr = 10(6)) highly glycosylated chondroitin sulfate proteoglycan found associated with Schwann cell and electrocyte basement membranes in elasmobranch electric fish. Previously, purified PG-1000 was visualized in the electron microscope as a "bottlebrush" structure about 345 nm long with about 20 side projections of 113 nm. This molecule was characterized with material purified from electric organ under denaturing and reducing conditions. Here we report that PG-1000, when purified under denaturing conditions without exposure to a reducing agent, exists as a complex of several proteins. In addition to PG-1000, this complex consists of a somewhat smaller, heavily glycosylated protein (beta component) and three smaller proteins with Mr values of 39,000, 21,000, and 18,000. The complex remains intact when exposed to denaturing and non-reducing conditions but falls apart in denaturing and reducing conditions. Presumably the complex is stabilized by disulfide bonds. The beta component of the PG-1000 complex is probably a proteoglycan. However, unlike PG-1000, the beta component does not contain chondroitin sulfate chains and lacks the epitope, T1, that is found on PG-1000. Both molecules share a protease-insensitive antigenic site, SV4, which is probably a modified keratan sulfate epitope. Evidence for the identity of this antigen is that it is found as a minor subfraction in commercial preparations of shark cartilage chondroitin and corneal keratan sulfates but not in other glycosaminoglycan preparations. These SV4 antigens are resistant to chondroitin ABC lyase digestion. However, the SV4 antigen in commercial keratan sulfate is cleaved by keratinase to a smaller antigenic fragment.

Animals↗

PubMed1991

Rescue of thymocytes and T cell hybridomas from glucocorticoid-induced apoptosis by stimulation via the T cell receptor/CD3 complex: a possible in vitro model for positive selection of the T cell repertoire.

Positive and negative selection events are involved in determining useful T cell clones to mature in the thymus. Accumulating evidence suggests that immature self-reactive thymocytes undergo apoptotic death (negative selection) upon stimulation via the T cell receptors (TcR). A similar phenomenon of activation-induced death has been reported in T cell hybridomas. On the other hand, little is known about the mechanism of the positive selection. Apoptosis in rodent thymocytes or T cell hybridomas is also known to be induced by glucocorticoids in vitro at concentrations within the physiologic range. We report here that the TcR/CD3-mediated stimulation and glucocorticoids mutually inhibit the apoptosis in T cell hybridomas. The production of interleukin 2 by the rescued cells indicated that the TcR/CD3-mediated signal was transduced into the cells. Thymocytes were also rescued from glucocorticoid-induced apoptosis by the stimulation with antibodies to TcR/CD3 molecules. The rescue of thymocytes, however, was observed only at a narrow concentration range of each of the antibodies, suggesting that the proper stimulation via the TcR/CD3 is required for the rescue. If thymocytes in situ are differentially stimulated according to the affinity of the TcR towards self, only the thymocytes whose TcR have proper affinity towards self may be rescued from glucocorticoid-induced apoptosis. Therefore, we propose a hypothesis that the positive selection of the T cell repertoire is based on the inhibition of glucocorticoid-induced apoptosis in immature thymocytes bearing TcR with proper affinity for self by the TcR-mediated signals in situ. Furthermore, the selection may be influenced by the peak level of glucocorticoid concentration, since the proper concentration range of the anti-TcR/CD3 antibody for the rescue was variable depending on the glucocorticoid concentration.

Animals↗

PubMed1991

A case of primary malignant lymphoma of the liver.

Primary lymphoma of the liver is extremely rare, and its preoperative or premortem diagnosis is still difficult. The author report here a case of primary malignant lymphoma of the liver diagnosed on a basis of ultrasonically guided biopsy of the tumor. A 51-year-old man was found to have a relatively large tumor in the right lobe of the liver as well as elevated serum LDH with abnormal isoenzyme pattern. Immunohistological studies of both biopsy and postmortem specimens of the tumor indicated T cell malignant lymphoma of the liver. The present case appears to be the second case of T cell origin of the disease.

Humans↗

PubMed1991

Surgery in acute pancreatitis. The Japanese experience.

Seventy-eight cases of severe acute pancreatitis were admitted to Mie University and its affiliated hospitals. These were subdivided into Group I (1976-1983) and Group II (1984-1989). The rate of early death was 34.8% in Group I and 9.3% in Group II. Among operated cases, peritoneal drainage alone was not effective with the worst mortality rate of 47.1%, especially in gallstone pancreatitis, with a 100% mortality rate. Early detection of infected necrosis or abscess using enhanced CT and subsequent drainage should be performed in cases of severe acute pancreatitis. A total 1182 cases of severe acute pancreatitis out of 12,309 cases of acute pancreatitis were collected in Japan by Saito et al., who belong to the Research Committee of Intractable Diseases of the Pancreas supported by the Japanese Ministry of Health and Welfare. Furthermore, 473 cases of severe acute pancreatitis in the Japanese literature reported from 1987 to 1990 were reviewed. Then, surgical indications and procedures were discussed. The incidence of necrosectomy has been increased to 10.3% from 3%, and biliary drainage procedure increased for severe acute pancreatitis. Indication of necrosectomy with or without open drainage method should be carefully evaluated in each institution.

Acute Disease↗

PubMed1991

Kinetic studies of growth hormone and prolactin during adaptation of coho salmon, Oncorhynchus kisutch, to different salinities.

The kinetics of growth hormone (GH) and prolactin (PRL) in coho salmon (Oncorhynchus kisutch) transferred from fresh water (FW) to seawater (SW) and vice versa were examined to help clarify the osmoregulatory roles of the two hormones during periods of migration to different salinities. Chum salmon GH or PRL was administered by a single injection intraarterially, and metabolic clearance rate (MCR) and secretion rate (SR) of injected hormones were calculated from the disappearance of the hormones from the plasma. When coho salmon smolts were acclimated to SW, MCR, SR, and plasma level of GH in SW-adapted (2-3 weeks) fish were twice as great as those in fish in FW. On the other hand, there was no difference in the kinetics of GH between the adult coho salmon in SW and those adapted to FW (2-3 weeks). The transfer of the adult coho salmon from SW to FW was followed after 2 days by a rise in plasma level and SR of PRL, which tended to stay at high levels after 2-3 weeks. The MCR of PRL increased significantly after 2-3 weeks in FW. These results support the likelihood of an important role of GH in SW adaptation and of PRL in FW adaptation in coho salmon.

Adaptation, Physiological↗

PubMed1991

Immature teratoma of the ovary.

The purpose of this study was to establish the optimal management of immature teratoma of the ovary. Pursuant to this, 20 previously untreated patients with immature teratoma were evaluated. Nine patients were at stage I of the disease, 2 had progressed to stage II, and 9 to stage III. Eight patients had grade 1 tumors, 11 had grade 2 tumors, and 1 had a grade 3 tumor. Postoperative chemotherapy was performed in 19 cases. Vincristine, actinomycin D, and cyclophosphamide (VAC) were administered in 9 cases, chemotherapy including cisplatin (P) was administered in 8 cases, and other regimens were followed in the 2 remaining cases. The median follow-up period was 62 months (range 19-108 months), and no patient was lost to follow-up. After completion of the follow-up period, 18 patients were alive and disease free, 1 was alive with liver metastasis, and 1 had died. The patient who died had suffered from a grade 3 tumor, and the recurrent tumor was a rhabdomyosarcoma. As a result of this study, it was found that immature teratoma of grades 1 and 2 can be managed successfully with VAC or P therapy. Thus, a hysterectomy should not be automatically performed in patients who still hope to give birth, yet suffer from a grade 1 or 2 immature teratoma at the time of a second operation.

Abdominal Neoplasms↗

PubMed1991

Sequence-dependent termination of mammalian DNA polymerase reaction by a new platinum compound, (-)-(R)-2-aminomethylpyrrolidine(1,1-cyclobutane-dicarboxylato)-2-plati num(II) monohydrate).

We examined the mechanism of the inhibition of DNA synthesis by a new platinum compound, (-)-(R)-2-aminomethylpyrrolidine(1,1-cyclobutane-dicarboxylato+ ++)-2-platinum(II) monohydrate (DWA-2114R), a derivative of the antitumor drug cis-diamminedichloroplatinum(II) (CDDP), using prokaryotic and eukaryotic DNA polymerases. Preincubating activated DNA with CDDP or DWA-2114R reduced its template activity for prokaryotic and eukaryotic DNA polymerases in a dose-dependent manner. DWA2114R required six times greater drug concentration and two times longer incubation time to show the same decrease of the template activity compared to CDDP. Treatment of primed pUC118 ssDNA templates with the two drugs followed by second-strand synthesis by prokaryotic and eukaryotic DNA polymerases revealed that DWA2114R bound to DNA in a similar manner to CDDP and these adducts blocked DNA elongation by DNA polymerases of eukaryotes as well as of prokaryotes. With these two drugs, the elongations by E. coli DNA polymerase I (Klenow fragment), T7 DNA polymerase and calf thymus DNA polymerase alpha were strongly arrested at guanine-guanine sequences (GG). Stop bands were also observed at adenine-guanine sequences (AG) guanine-adenine-guanine sequences (GAG) and mono-guanine sequence (G). Calf testis DNA polymerase beta was also arrested efficiently at AG, GAG and G, but much more weakly at GG. This pattern was common to DWA2114R and CDDP.

Animals↗