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Biomedical subjects

K Okamoto

Publications and source records attributed to K Okamoto.

At least 145 records · Page 8Linked to original sources
PubMed2001

Developmental changes in the fine structure and histochemical properties of mucous cells in the parotid gland of the infant Japanese macaque.

Mucous cells have been known to occur in the terminal portions of the parotid gland in a few species of mammals during a limited period of their development. The aim of this study was to examine the occurrence and features of mucous cells in the parotid gland of the infant Japanese macaque. Light microscopy revealed that mucous cells in the macaque parotid gland were present in the terminal clusters and acini at postnatal day 15, were less prevalent at day 30, and continued to decrease in number over 3 months. Mucous cells were no longer recognized in the parotid gland in 6-month-old macaques. Electron microscopy showed that the mucous cells contained electron-lucent secretory granules and bipartite or tripartite secretory granules. By 3 months of age, there was a scarcity of mucous cells and a concomitant increase in transitional cells. These transitional cells were intermediate in structure between mucous and serous cells, and contained three types of granules: electron-lucent, bipartite or tripartite, and electron-dense. None of the cells showed apoptotic figures. Lectin histochemistry indicated that the mucous cells in the early postnatal period had sugar residues identical in nature to those seen in the granules from mature serous cells in the glands of 3-month-old macaques. Immunohistochemistry using an antibody against human alpha-amylase showed a weakly positive reactivity in the secretory granules of the mucous cells, starting from day 15. In the transitional cells, the electron-dense granules showed a stronger immunoreactivity than either the electron-lucent granules or the heterogeneously structured granules. These results suggest that the secretory granules of mucous cells have characteristics in common with those of serous cells, and that during the transitional period the mucous granules change from the initial electron-lucent to hetorogenous forms, finally becoming the electron-dense granules. The mucous cells in the parotid gland of the juvenile Japanese macaque are therefore suggested to be converted into serous cells.

Animals↗
PubMed2001

EST analysis of genes that are expressed in the neural complex of Ciona intestinalis adults.

A subtractive cDNA library was made corresponding to mRNAs expressed in the neural complex relative to those expressed in the pharynx of adults of the ascidian Ciona intestinalis. Determination and comparison of expressed sequence tags (ESTs) of a set of 1,527 randomly selected clones demonstrated that they represent 832 independent sequences. Five hundred seventy-two of the clones contained amino-acid-encoding sequences. BLASTX analyses showed that 342 of the 572 clones were strong matches (P < 10(-7)) to previously identified proteins, while the remaining 230 fell into the "no match" category. Among the clones matching previously identified proteins, about 80 clones represented proteins that are involved in the formation, maintenance of the structure, and function of the nervous system: 22 proteins are associated with signal transduction, five proteins are related to the synapse, 11 to transcription factors, nine to transporters, five to enzymes, and 13 to extracellular matrix and cytoskeletal components, and six to apoptosis. In addition, sequence information for genes associated with the immune system and for genes encoding proteins with interesting functions were obtained. These data provide cues for further studies on genes that are expressed in and function in the ascidian nervous system.

Animals↗
PubMed2001

Malignant fibrous histiocytoma of the heart: case report and review of 46 cases in the literature.

A rare case of cardiac malignant fibrous histiocytoma (MFH) is reported. A 55-year-old woman complained of palpitation due to atrial fibrillation. Echocardiography, magnetic resonance imaging, and angiography demonstrated a tumor arising from the posterior wall of the left atrium. At surgery, the tumor was almost entirely resected and histologically defined as MFH. Neither chemotherapy nor irradiation was administered. Echocardiography revealed a local recurrence two months after the surgery and the patient died of advanced cachexy and heart failure 2 years later. The details of this case are presented with a review of the literature.

Age Factors↗
PubMed2001

[Three elderly cases of hyperostosis cranii with various clinical symptoms].

We report three elderly patients with hyperostosis cranii (HC). Patient 1 had two episodes of unconsciousness; patient 2, headache; and patient 3, dementia. On the basis of the classification of Moore using skull films, patients 1 and 2 showed hyperostosis frontoparietalis and patient 3 had hyperostosis frontalis interna. Electroencephalography showed transient generalized spike and slow wave complexes over the frontal lobes in patient 1. Magnetic resonance (MR) images showed frontal lobes compressed by the thickness of the frontal bones in all patients and thickened parietal bones in patients 1 and 2. Because findings in our series and in the literature suggest that HC may show unexpected neuropsychiatric symptoms, HC should be checked in elderly patients whose presenting symptoms include epilepsy, dementia, psychiatric disease, headache and so on. MR images should reveal the relationship between clinical symptoms and the deformation of brains by the skull.

Aged↗
PubMed2001

Diltiazem, a calcium antagonist, inhibits matrix metalloproteinase-1 (tissue collagenase) production and collagenolytic activity in human vascular smooth muscle cells.

Calcium antagonists (CAs) are widely prescribed for patients with cardiovascular diseases. CAs have been reported to inhibit smooth muscle cell (SMC) proliferation in addition to their effects on vascular tone. To determine whether CAs potentially affect vascular remodeling, we measured the expression of matrix-degrading enzymes in growth factor-stimulated SMC. Human cultured SMC were stimulated with 10 ng/ml of platelet-derived growth factor (PDGF)-BB with or without a calcium antagonist, diltiazem. In the cell counting assay, diltiazem (10-5 M) alone had no effect on the proliferation of quiescent SMC, however 10-6-10-5 M of diltiazem dose-dependently inhibited PDGF-stimulated SMC proliferation. The inhibitory effects of diltiazem on SMC proliferation were further confirmed by a 5-bromo-2'-deoxyuridine (BrdU) incorporation assay and flow cytometry. In Western blotting, matrix metalloproteinase (MMP)-1 (tissue collagenase) but not MMP-2 (72-kDa gelatinase) expression was upregulated by PDGF and phorbol ester (TPA), which were reduced by diltiazem in a dose-dependent manner. The downregulation of MMP-1 expression was consistent with the reduction of collagenolytic activity measured by a FITC-conjugated type I collagen breakdown assay. PDGF-stimulated c-Jun/AP-1 expression, a major transcriptional factor for MMP-1, was not affected by diltiazem. In contrast, intracellular calcium ions measured with a fluorometric assay of Fluo-3AM-loaded cells revealed that the PDGF-stimulated increase in the intracellular calcium content was dose-dependently reduced by diltiazem. Our data suggest that diltiazem inhibits not only proliferation but also MMP-1 expression and collagenolytic activity in PDGF-stimulated SMC. The administration of CAs potentially influences the process of vascular remodeling, and this possibility should be further verified in vivo.

Blotting, Western↗
PubMed2001

[Evaluation of superior transseptal approach for the removal of left atrial myxoma].

We compared the operative outcomes among 14 patients who underwent the removal of left atrial myxoma with four different approaches; right lateral (n = 2), transseptal bi-atrial (Dubost, n = 4), conventional transseptal (n = 4) and superior transseptal approach (STA, n = 4). Concomitant operations were performed in 4 cases (CABG, two; aortic valvuloplasty, one; mitral valve replacement, one), and two out of 4 cases were in the STA group. The mean operation, cardiopulmonary bypass and aortic cross-clamp times were shorter in the STA group compared to the other three group. The total amount of postoperative drain discharge and the peak value of creatine kinase were also lower in the STA group compared to the other three groups. Among the patients in sinus rhythm before operation, the use of STA was associated with a greater incidence (100%) of postoperative atrial fibrillation or junctional rhythm. These rhythm disturbances were temporary, and all returned to sinus rhythms during hospital stay. We conclude that STA is an excellent approach with a nice surgical view to expose and remove the left atrial myxoma.

Adult↗
PubMed2001

[Two cases of acute eosinophilic pneumonia--analyses of cytokines in BALF before and after treatment].

Acute eosinophilic pneumonia (AEP) has been well recognized as sudden onset respiratory failure characterized by an increased eosinophilic cell count in the bronchoalveolar lavage fluid (BALF). Although several lines of research have demonstrated that the Th2 cytokine network is likely to play a pivotal role in the development of AEP, that mechanism has not been clearly understood yet. Previous reports published in Japan demonstrated that the BALF CD4/CD8 ratio in patients with AEP ranged between 1.1 and 5.8. In this report, we describe 2 cases of AEP in which the CD4/CD8 ratios were 0.3 and 7.8 when present. We measured IL-4, IL-5, IL-10 and IFN gamma in the BALF before and after treatment in these patients. IL-5 decreased drastically after the treatment phase, while the other cytokines did not change much. We concluded that the IL-5 concentration in the BALF is probably related to the development of AEP. In addition, we also speculated that the CD4/CD8 ratio in BALF from patients with AEP may be affected whether a patient has an atopic background or not.

Acute Disease↗
PubMed2001

[A case of pulmonary Mycobacterium avium infection with a rapid-growing solitary node].

A 72-year-old man was admitted to our hospital because of an abnormal shadow on his chest radiograph. Computed tomography revealed a 3 cm solitary nodular opacity in the right S1. Bronchofiberscopy could neither give any specific histological findings nor bacteriological findings. This nodular shadow increased in size to 1.5 times that in the first chest radiograph. In addition, since there was no abnormal finding in the chest radiograph one year before, we performed partial pulmonary resection by video-assisted thoracoscopic surgery, taking into consideration the possibility that the solitary node was malignant. The pathological findings of the resected specimen were an epitheloid cell granuloma with Langhans giant cell and caseous necrosis. We could not detect any acid-fast bacilli or malignant cells. After surgery, M. avium was detected in a 6-week culture of the resected specimen. We treated the patient with RFP, EB and CAM for 6 months. Outpatient follow-up revealed no relapse.

Aged↗
PubMed2001

Expression patterns of cancer testis antigens in testicular germ cell tumors and adjacent testicular tissue.

PURPOSE: The human cancer-testis antigens (CTAs) are a group of tumor specific antigens recognized by cytotoxic T lymphocytes whose expression occurs in human malignancies as well as in normal testicular tissue. We studied a series of CTA gene transcripts in testicular germ cell tumors of various histological types to test the hypothesis that the expression of CTA in testicular germ cell tumors reflects developmental stages of tumorigenesis rather than constitutive tumor antigens recognized by cytotoxic T lymphocytes. MATERIALS AND METHODS: Total RNA was obtained from 31 primary and 3 metastatic testicular germ cell tumors, and 11 parenchymal tissues adjacent to the testicular germ cell tumors. We performed an expression study of the CTA genes MAGE-A, MAGE-B, GAGE, PAGE-1, HOM-MEL-40 (SSX2), NY-ESO-1, LAGE-1 and SCP-1 in these samples using reverse transcriptase-polymerase chain reaction. RESULTS: The results showed that expression patterns of CTA genes depended on the histological differentiation of the testicular germ cell tumors. Overall CTA expression was more common in seminomas than in nonseminomatous germ cell tumors. Specifically all 13 seminomas (100%) demonstrated the positive expression of MAGE-B1 and MAGE-B2, while 3 of 17 nonseminomatous germ cell tumor samples (18%) showed positive expression of these genes. All 5 teratomatous elements (100%) had homogenous null expression with regard to all CTA genes examined. In addition, we detected deficiencies in CTA expression in 7 of 11 parenchymal tissues adjacent to the testicular germ cell tumors (64%). CONCLUSIONS: These data support the idea that CTA transcripts in testicular germ cell tumors serve as developmental footprints of testicular germ cell tumors rather than as constitutive tumor antigens recognized by cytotoxic T lymphocytes.

Antigens, Neoplasm↗
PubMed2001

[Simultaneous mitral and aortic valvuloplasty using rasping procedure for combined valvular disease: a case report].

We reported a case of successful simultaneous mitral and aortic valvuloplasty using rasping procedure. A 55-year-old woman with combined valvular disease received this operation. Postoperatively, the mitral valve area increased from 1.15 cm2 to 2.03 cm2. Mitral regurgitation improved. Aortic valve pressure gradient decreased from 21 mmHg to 0 mmHg. Aortic regurgitation also improved. Cardiac Index (CI) increased from 1.94 l/min./m2 to 2.59 l/min./m2. Ejection fraction (EF) also increased from 60% to 82%. The postoperative course was uneventful. Excellent postoperative results of this procedure may be expected, not only in single valvular disease but also in combined valvular disease.

Aortic Valve↗
PubMed2001

[Inhaled nitric oxide therapy].

Inhaled nitric oxide (INO) therapy is becoming an indispensable measure in some critically ill patients with pulmonary hypertension. Most importantly, it has been shown that INO significantly reduces the necessity for extracorporeal lung assist in newborns with hypoxemic respiratory failure and pulmonary hypertension. A large number of basic and clinical studies are making great steps in delineating its physiology, techniques, side effects, and clinical efficacy. This article reviews the current knowledge of INO therapy including a novel device of nitric oxide production system.

Administration, Inhalation↗
PubMed2001

[Three-dimensional reconstructions with volume-rendering method of the arytenoid and cricoid cartilages by means of multidetector row CT].

We created volume-rendering (VR) three-dimensional (3-D) images of the larynx using a multidetector row CT. The study included 17 examinations of 15 patients. After obtaining volume data of the larynx, VR 3-D images of airways and arytenoid and cricoid cartilages were reconstructed. The threshold of airways and calcification were set as -1025/-625 HU and 80/1560 HU, respectively. The base of the vocal processes of arytenoid cartilages and cricoarytenoid joints were demonstrated at rates of 70.6% and 53.4%, respectively. VR 3-D laryngeal images were more useful in assessing anatomy than the surface-rendering images previously reported.

Adolescent↗
PubMed2001

Collagenolytic activity of a cell wall preparation from Fusobacterium necrophorum subsp. necrophorum.

A collagenolytic preparation of Fusobacterium necrophorum subsp. necrophorum was derived from the bacterial cell. It was further treated for gel permeation with Toyopearl HW 50, followed by Sepharose 4B column chromatography. In sodium dodecyl sulphate polyacrylamide gel electrophoresis, the final preparation exhibited one definite band and at least one faint band. It was inactivated completely by adjusting the pH to 4.0 or by heating at 80 degrees C for 30 min.

Animals↗
PubMed2001

[Effect of monoclonal antibody-neocarzinostatin conjugate for gastric cancer with peritoneal dissemination--comparison between early and late administration].

A7-NCS, which is a conjugate of the monoclonal antibody A7 against a human colonic cancer and the anticancer agent neocarzinostatin (NCS), reacts with human gastric cancers at a high rate. The anticancer effect of A7-NCS is stronger than that of free NCS. Nude mice models of peritoneal dissemination were established simply by intra-peritoneal inoculation of the antigen-positive human gastric cancer cell line MKN45. Using these models, the anticancer effect of A7-NCS against the peritoneal dissemination of gastric cancer was examined. The murine peritoneal dissemination models were divided into three groups. The anticancer effect of the group injected intra-peritoneally with A7-NCS 2 days after cancer inoculation was compared with that injected 18 days after inoculation. The anticancer effect in the 18-day group was inferior to that in the 2-day group, but was superior to that in the non-treated group. To get a better result in the 18-day group, which is in the advanced stage of peritoneal dissemination, repeated injection and the dose of A7-NCS should be examined.

Animals↗
PubMed2001

Resuscitation and evaluation of non-beating hearts obtained from asphyxiated dogs via autoperfusing heart-lung circuit.

BACKGROUND: The shortage of donor hearts has made use of non-beating hearts as cardiac grafts an attractive possibility for heart transplant candidates. The purpose of this study was to evaluate the utility of leukocyte-depleted hot shot cardioplegia for resuscitation of non-beating hearts obtained from asphyxiated dogs via an autoperfusing heart-lung circuit. METHODS: Mongrel dogs were divided into 3 groups according to the warm ischemia time and the method of reperfusion before starting the autoperfusing heart-lung circuit. Group A (n=4) had 60 minutes of warm ischemia and reperfusion without leukocyte-depleted hot shot, Group B (n=5) had 30 minutes of warm ischemia and reperfusion with leukocyte-depleted hot shot, and Group C (n=7) had 60 minutes of warm ischemia and reperfusion with leukocyte-depleted hot shot. We calculated stroke work via the heart-lung circuit to evaluate cardiac function of the resuscitated hearts. The criteria for "recovery" has been reported elsewhere. Myocardial water content of the resuscitated hearts was also measured and analyzed. No inotropic agents were used. RESULTS: The recovery rates in groups A, B and C were 0%, 80% and 57%, respectively, and the group B rate was significantly higher than the group A rate (p=0.04). Although myocardial water content did not differ between groups B and C, it was significantly lower in recovered hearts than in non-recovered hearts (p=0.04). Significant negative correlation was observed between the maximum stroke work value and myocardial water content in the resuscitated hearts (r=0.668, p=0.03). CONCLUSIONS: The autoperfusing heart-lung circuit is useful for evaluation and maintenance of cardiac function. Our experimental data shows that leukocyte-depleted hot shot plays a great role for resuscitation and recovery of non-beating hearts.

Animals↗
PubMed2001

[Channelopathy].

Recently, a variety of ion channel defects have been identified as the biological basis of certain familial epilepsies, paroxysmal movement disorders, myopathies and some degenerative disorders of central nervous system. Ion channel defects were mainly caused by genetic and autoimmune mechanisms. Here, we reviewed several channelopathies including spinocerebellar ataxia type 6, familial hemiplegic migraine, episodic ataxia type 2, familial hypokalemic periodic paralysis, congenital myotonia, malignant hyperthermia, epilepsy, Gitelman syndrome and Lambert-Eaton syndrome.

Autoantibodies↗
PubMed2001

[Familial hypokalemic periodic paralysis].

Recent genetic studies have identified mutations in the genes causative for familial hypokalemic periodic paralysis (F-HypoPP) . The major locus for F-HypoPP is the skeletal muscle calcium channel alpha(1S) subunit (CACNA1S), and two predominant missense mutations were found in the same gene. A small part of other F-HypoPP families has been identified to result from the missense mutations found in the skeletal muscle sodium channel alpha subunit (SCN4A) gene. We analyzed Japanese hypokalemic periodic paralysis patients (familial, sporadic and thyrotoxic), and detected the Arg 528His mutation in two F-HypoPP families. Thus F-HypoPP is related to the functional deficiency of the skeletal muscle ion-channels.

English Abstract↗