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Biomedical subjects

H Moriyama

Publications and source records attributed to H Moriyama.

At least 73 records · Page 4Linked to original sources
PubMed2000

[Endoscopic endonasal surgery with image-guidance].

We evaluated the advantages and disadvantages of image-guided endoscopic endonasal surgery for various diseases. Thirty-three patients, including 8 with chronic sinusitis, 14 with paranasal cysts, 1 with paranasal tumor (biopsy), 1 with sellaturcial cyst (Rathke's cleft cyst) and 9 with pituitary tumors were endonasally operated on from September 1998 to May 1999, with an electromagnetic navigation system, The Insta Trak (Visualization Technology Inc. USA). The Insta Trak system is composed of a computer, a metal probe with a nonmetallic suction tube attachment, and a soft-type headset with an electromagnetic sensor. This freehand, armless system compensates well for patient's head movement during surgery, and precludes the need for head fixation. Either straight or curved suction tube (probe) can be used to access almost of all pathological sites in the sinus cavity. Location of the metal probe is displayed on the computer moniter as an intersection point on the axial, coronal and sagital CT images. In all cases, Insta Trak showed the surgeon the appropriate location and direction of each lesion. The Insta Trak also indicated the location of the orbit, optic canal, nasolacrimal duct and/or skull base, thus, preventing intraoperative complications. When the anatomy was distorted by previous surgery and/or when there was uncontrollable bleeding from a severe lesion so that the surgeon had difficulty finding the proper orientation, the usefulness of image-guided surgery was sufficiently recognized. However, the following disadvantages were also pointed out. An additional 15 to 20 minutes is needed for equipment set up and operation, unless the surgeon and the operation room staff are familiar with the machine. The patient's CT image used for navigation relies on data obtained preoperatively, that is to say, it can not reflect morphological changes produced during surgery. Moreover, the surgeon must consider possible errors of the navigational point that may result in the headset during surgery, as well as, errors the machine may originally possess. The image-guided system successfully integrated the most up-to-date computer technology with a surgeon's anatomical knowledge for improved treatment of endoscopic endonasal surgery. However, we also concluded that the system should be used as a surgical supporting device for safer and more adequate procedures.

Endoscopy↗
PubMed2000

[Efficacy of endoscopic transethmoidal.transsphenoidal surgery for pituitary tumors].

Endoscopic transethmoidal.transsphenoidal surgery was performed on 30 patients with pituitary tumors, and the usefulness of this procedure was evaluated. As with conventional endoscopic intranasal surgery, the ethmoidal sinuses were opened and a broad window was created in the ethmoidal sinus from the directions of the middle meatus and the olfactory cleft. Then an endoscopic washing device was attached to a 0 degree or 30 degrees rigid endoscope and it was immobilized in the left nasal cavity with an endoscope immobilization apparatus. Removal of the tumor was then started from the right side by a bimanual technique. Based on the results, this surgical procedure was judged to be useful for the following reasons (1) it makes it easy to carry out the operative manipulations even in a narrowed nasal cavity, thereby reducing the overall time required for surgery, and (2) it is possible to prevent postoperative deformities of the nasal cavity morphology caused by pressure on its lateral wall. In additional, (3) the surgical wound can be observed, and CSF leakage can be repaired immediately after completion of the operation. Corrective surgery can be performed on an outpatient basis early after the initial operation to correct postoperative deformities of the nasal paranasal cavities, which might later cause nasal obstruction or an olfactory disturbance. Finally, (4) employing the route of endoscopic transethmoidal.transsphenoidal surgery facilitates the performance of a second operation soon, or even several months, after the first operation. A second operation may be necessary in the event of recurrence of the pituitary tumor or complication by chronic sinusitis. On the basis of our experience in the this study, we conclude that our method of endoscopic transethmoidal.transsphenoidal surgery will be useful for reducing invasiveness in the nasal cavities and achieving maximum prevention of postoperative complications. In order to fulfill its potential, neurosurgeons will need to master forceps techniques in the visual field provided by the endoscope and to cooperate with otorhinologists who are skilled in endoscopic techniques.

Adult↗
PubMed2000

[A case of isolated sarcoidosis of the cerebral falx].

A 28 year-old man complaining of intermittent headaches for a month following an episode of general convulsions was admitted to the Department of Neurosurgery of our hospital. His brain CT scan showed a well-enhanced mass growing symmetrically along the anterior cerebral falx in a manner compatible with meningioma. Nothing abnormal was detected in chest radiography on admission. Histopathological examination of the mass after partial resection revealed multiple epithelioid cell granulomas with giant cells indicating sarcoidosis. After 4 weeks of treatment with oral prednisolone 30 mg/day, bronchoalveolar lavage was performed in our department. In the lavage fluid, both the total cell count and the percentage of lymphocytes were elevated. The lung specimens obtained by transbronchial biopsy also showed epithelioid cell granulomas. CNS sarcoidosis is reportedly usually observed in the vicinity of the hypothalamus with other organ involvement. In the present case, differential diagnosis of sarcoidosis from meningioma was difficult because the solitary lesion was growing along the anterior cerebral falx without radiographic evidence of bilateral hilar lymphadenopathy.

Adult↗
PubMed1999

Effect of eluent composition on retention behavior of anions in ion chromatography on anion-exchangers modified with heparin.

Effect of eluent composition on retention behavior of inorganic anions have been investigated in ion chromatography using anion-exchangers modified with heparin. Both cation and anion of the eluent affected the retention of analyte anions and unusual retention behavior was observed on the modified stationary phase. The retention time of anions decreased with decreasing eluent concentration when sodium sulfate, magnesium sulfate and chlorides of alkali metals were used as the eluent, whereas it increased with decreasing eluent concentration when aluminum sulfate, copper sulfate and sulfuric acid were used as the eluent. The retention of nitrate increased in the order of Li+, Na+, K+, Rb+ and Cs+ when their chlorides were used as the eluent. When sodium perchlorate and chlorides of alkaline-earth metals were used as the eluent, the eluent should include heparin. Otherwise, the modifier was partially bled from the column.

Anions↗
PubMed1999

Molecular characterization of two endogenous double-stranded RNAs in rice and their inheritance by interspecific hybrids.

We completely sequenced 13,936 nucleotides (nt) of a double-stranded RNA (dsRNA) of wild rice (W-dsRNA). A single long open reading frame (13,719 nt) containing the conserved motifs of RNA-dependent RNA polymerase and RNA helicase was located in the coding strand. The identity between entire nucleotide sequence of W-dsRNA and that of the dsRNA of temperate japonica rice (J-dsRNA, 13,952 nt) was 75.5%. A site-specific discontinuity (nick) was identified at nt 1,197 from the 5' end of the coding strand of W-dsRNA. This nick is also located at nt 1,211 from the 5' end in the coding strand of J-dsRNA. The dsRNA copy number was increased more than 10-fold in pollen grains of both rice plants. This remarkable increase may be responsible for the highly efficient transmission of J-dsRNA via pollen that we already reported. J-dsRNA and W-dsRNA were also efficiently transmitted to interspecific F1 hybrids. Seed-mediated dsRNA transmission to F2 plants was also highly efficient when the maternal parent was wild rice. The efficiency of dsRNA transmission to F2 plants was reduced when the maternal parent was temperate japonica rice; however, the reduced rates in F2 plants were returned to high levels in F3 plants.

Base Sequence↗
PubMed1999

p16 inactivation in small-sized lung adenocarcinoma: its association with poor prognosis.

p16, an inhibitor of cell cycle machinery, is frequently inactivated in non-small cell carcinoma of the lung (NSCCL). To clarify the significance of p16 inactivation in the progression of lung adenocarcinoma, we immunohistochemically evaluated p16 protein status and Rb, p53 and cyclin D1 expression in 51 surgically resected adenocarcinomas that were less than 3 cm in diameter (median follow-up period: 52.5 months). Twenty-one of 51 adenocarcinomas showed negative immunostaining for p16. Twenty adenocarcinomas were also negative for Rb, while 31 and 13 were positive for p53 and cyclin D1, respectively. Loss of p16 expression was significantly correlated with scar grade, lymphatic permeation, lymph node metastasis and clinical stage. Rb protein expression was also inversely correlated with scar grade, pleural involvement and vascular invasion. When the cases were stratified according to the expression of both proteins, the Rb-/p16- subset (7/51) consisted of poorly differentiated adenocarcinoma with a higher grade of invasion. While Rb, p53 and cyclin D1 protein status showed no significant correlations with prognosis, p16 inactivation was significantly correlated with poor prognosis, and the prognosis of Rb-/p16- was the worst among the 4 subsets. Inactivation of p16 may play a role in accelerating scar formation and lymph node metastasis, and may contribute through these mechanisms to poor prognosis in patients with small-sized lung adenocarcinoma.

Adenocarcinoma↗
PubMed1999

Medium temperature, 310 K, provides single crystals of orotate phosphoribosyltransferase from Thermus thermophilus.

Crystallization of orotate phosphoribosyltransferase from a thermophilic organism, Thermus thermophilus, was achieved using the hanging-drop vapour-diffusion method coupled with a macroseeding starter. Small needle-like microcrystals were grown in a fresh protein solution in the presence of 2-methyl-2,4-pentanediol at 298 K or below. Although these normal temperature conditions caused stacking crystallization, an increase of temperature to 310 K permitted crystal growth. This was because of increased enzyme solubility at the higher temperature. The crystal was found to belong to the monoclinic space group P21with unit-cell parameters a = 44.4, b = 59.6, c = 67.8 A and beta = 98.3 degrees.

Crystallization↗
PubMed1999

Role of Bcl-xL protein in differentiation and apoptosis of human middle ear cholesteatoma epithelium.

OBJECTIVE: To compare the mechanisms of proliferation, differentiation, and apoptosis in middle ear cholesteatoma epithelium with those of normal external ear canal epithelium. DESIGN: The localizations of the expression of Bcl-xL protein and involucrin and the presence of apoptotic cells were determined for tissue slices of middle ear cholesteatoma epithelium and compared with the findings for normal external ear canal epithelium. In addition, SCC-25/bcl-xL transfectants showing the overexpression of Bcl-xL were used to investigate the effect of this protein on the expression of involucrin, which is a marker of epithelial cell differentiation. MATERIALS: Cholesteatoma tissue specimens were surgically excised from 10 patients. Normal skin specimens collected from the external ear canal of the 10 patients were used as control specimens. RESULTS: The expression of Bcl-xL was detected in the vicinity of the basal cell layer of both the cholesteatoma epithelium and the normal external ear canal epithelium. Conversely, the expression of involucrin (ie, a marker of epithelial cell differentiation) increased in proportion to the shallowness of the epithelial layer. In situ labeling detected apoptotic cells in the spinous and granular cell layers of cholesteatoma tissue sections and similar findings in the normal external skin specimens. Western blot analysis confirmed that the expression of involucrin protein was the same in both wild-type SCC-25 cells and the SCC-25/bcl-xL transfectants. CONCLUSIONS: In both the cholesteatoma epithelium and the normal external ear canal epithelium, differentiation and apoptosis begin when the epithelial cells separate from the basal cells. The mechanisms behind these changes, at least in apoptosis, appear to be controlled by the expression of the Bcl-xL protein.

Adult↗
PubMed1999

Unusual inheritance of evolutionarily-related double-stranded RNAs in interspecific hybrid between rice plants Oryza sativa and Oryza rufipogon.

Endogenous, 14 kb double-stranded RNAs (dsRNAs) have been found in two ecospecies of cultivated rice (temperate japonica rice and tropical japonica rice, Oryza sativa L.) and in wild rice (O. rufipogon, an ancestor of O. sativa). A comparison of the nucleotide and deduced amino acid sequences of the core regions of the RNA-dependent RNA polymerase domains found in these three dsRNAs suggested that these dsRNAs probably evolved independently within each host plant from a common ancestor. These dsRNAs were introduced into F1 hybrids by crossing cultivated rice and wild rice. Unusual cytoplasmic inheritance of these dsRNAs was observed in some F1 hybrids; the evolutionarily related dsRNAs were incompatible for each other, and the resident dsRNA of an egg cell from cultivated rice was excluded by the incoming dsRNA of a pollen cell from wild rice. Coexisting dsRNAs in the F1 hybrids segregated away from each other in the F2 plants. However, the total amount of these dsRNAs in the host cells remained constant (ca. 100 copies/cell). The stringent regulation of the dsRNA copy number may be responsible for their unusual inheritance.

Base Sequence↗
PubMed1999

Relationship between severity of middle ear mucosal lesion and middle ear pneumatic space volume in patients with otitis media with effusion.

If we assume that the state of suppression of pneumatic cells is the result of suppression of pneumatic cell growth by inflammatory stimulation in the middle ear pneumatic space, it is possible to improve the state of suppression by performing sufficient treatment during the growth period of the pneumatic cells. We indwelt a tympanic membrane ventilation tube (hereinafter referred to as tube) for treatment of otitis media with effusion (OME) in child patients aged 3-13 years and investigated the following points: i) relationship between the severity of inflammation of the lamina propria of middle ear mucosal specimens (hereinafter referred to as lamina propria) collected at the time of tube indwelling and the degree of growth of the pneumatic space; and ii) changes in the pneumatic space associated with treatment by tube indwelling, which was studied by comparing the above-described mucosal severity with the pneumatic space area of 2 years after tube indwelling, and with increase in the pneumatic space volume measured periodically after tube indwelling. The results indicated that mastoid cell growth suppression is higher in patients with a higher degree of inflammatory changes in the lamina propria. In association with treatment by tube indwelling, effusion accumulated in the pneumatic space and mucosal swelling disappeared early after the treatment, or 2 months of tube indwelling. After that, in patients with severe mucosal lesion, a long time, 1.5-2 years, was found to be required for repneumatization accompanying regrowth of the temporal bone. We confirmed that the severity of inflammation of the lamina propria is deeply involved in the growth and repneumatization of the pneumatic cells.

Adolescent↗
PubMed1999

Roles of cytokines and cell cycle regulating substances in proliferation of cholesteatoma epithelium.

OBJECTIVES: It can be surmised that the cell cycle must be involved in cell proliferation of the epithelium of middle ear cholesteatoma. Thus a comparative study was conducted of the levels of expression of cyclin-dependent kinase 2 (cdk2) and cyclin-dependent kinase 4 (cdk4)-substances known to be involved in the cell cycle-in cholesteatoma epithelium and the normal epithelium of the bony region of the external ear canal. In addition, it has been reported that the expression of cytokines in the epithelium is accelerated in response to subepithelial inflammation. This suggests that an interaction between the epithelium and subepithelium, which is subject to paracrine regulation, is deeply involved in epithelial proliferation. Accordingly, attention was focused on interleukin-1alpha (IL-1alpha) and keratinocyte growth factor (KGF), cytokines which are found in the subepithelium, and experiments were conducted to elucidate their effects on the expression of the substances known to be involved in the cell cycle. METHODS: The expressions of cdk2 and cdk4 in the cholesteatoma epithelium and external ear canal epithelium were investigated by an immunohistochemical technique. In addition, cultured human keratinocytes were grown in medium containing IL-1alpha or KGF at concentrations of 0, 20, and 100 ng/mL, and the differences in the expression of cdk2 and cdk4 were investigated and compared by Western blot analysis. RESULTS: In the cholesteatoma epithelium specimens, cdk2 and cdk4 were observed to be expressed in the basal and parabasal layers and in the upper layer (prickle layer and granular layer). Their expression tended to be increased compared with their expression in the normal external ear canal epithelium, and this tendency was marked in subepithelial sites showing severe inflammation. In addition, exposure of cultured human keratinocytes to IL-la or KGF resulted in accelerated expression of both cdk2 and cdk4, and this was especially striking in the case of addition of KGF. CONCLUSION: It can be surmised that, in cholesteatoma, accelerated expression of IL-1alpha and KGF by inflammatory cells at subepithelial sites of inflammation leads to upregulation of cdk2 and cdk4 in epithelial cells and to cell proliferation. It was concluded that this is at least one sequence of events involved in the mechanism causing epithelial proliferation in cholesteatoma.

Adult↗
PubMed1999

Terminal differentiation of epithelial cells in middle ear cholesteatoma: investigation of patterns of expression of protein kinase C-delta and protein kinase C-eta.

OBJECTIVES: The objective of this study was to elucidate the differentiation mechanism of keratinocytes in cholesteatoma. STUDY DESIGN: To achieve the objective, we analyzed the expressions of various cellular proteins: the delta and eta isoforms of protein kinase C (PKCdelta and PKCeta), which are thought to play key roles in signal transduction in differentiation; cytokeratin 1 (CK1) and cytokeratin 10 (CK10) (cytoskeletal constitutive proteins); and involucrin (a marker of differentiation). METHODS: The materials used in this study were tissue specimens obtained from cholesteatoma epidermis, normal external ear canal skin, normal inguinal skin, and psoriatic skin. Immunohistochemical staining techniques were applied to compare the expressions of the above proteins (i.e., PKCdelta, PKCeta, CK1, CK10 and involucrin) in those various tissues. RESULTS: No clear differences in the patterns of expression of PKCdelta and PKCeta were found between the cholesteatoma epidermis and the normal external ear canal skin. These proteins were expressed mainly in the stratum spinosum and stratum granulosum, and their patterns of expression were almost the same as those of the CK1, CK10, and involucrin proteins. CONCLUSION: The findings of this study indicate that the terminal differentiation of keratinocytes in the cholesteatoma epidermis is the same as in normal skin tissues. It was concluded that the growth of epidermis which has undergone hyperproliferation of keratinocytes because of increased levels of various cytokines is being regulated by means of normal terminal differentiation.

Adult↗
PubMed1999

Prions in Saccharomyces and Podospora spp.: protein-based inheritance.

Genetic evidence showed two non-Mendelian genetic elements of Saccharomyces cerevisiae, called [URE3] and [PSI], to be prions of Ure2p and Sup35p, respectively. [URE3] makes cells derepressed for nitrogen catabolism, while [PSI] elevates the efficiency of weak suppressor tRNAs. The same approach led to identification of the non-Mendelian element [Het-s] of the filamentous fungus Podospora anserina, as a prion of the het-s protein. The prion form of the het-s protein is required for heterokaryon incompatibility, a normal fungal function, suggesting that other normal cellular functions may be controlled by prions. [URE3] and [PSI] involve a self-propagating aggregation of Ure2p and Sup35p, respectively. In vitro, Ure2p and Sup35p form amyloid, a filamentous protein structure, high in beta-sheet with a characteristic green birefringent staining by the dye Congo Red. Amyloid deposits are a cardinal feature of Alzheimer's disease, non-insulin-dependent diabetes mellitus, the transmissible spongiform encephalopathies, and many other diseases. The prion domain of Ure2p consists of Asn-rich residues 1 to 80, but two nonoverlapping fragments of the molecule can, when overproduced, induce the de nova appearance of [URE3]. The prion domain of Sup35 consists of residues 1 to 114, also rich in Asn and Gln residues. While runs of Asn and Gln are important for [URE3] and [PSI], no such structures are found in PrP or the Het-s protein. Either elevated or depressed levels of the chaperone Hsp104 interfere with propagation of [PSI]. Both [URE3] and [PSI] are cured by growth of cells in millimolar guanidine HCl. [URE3] is also cured by overexpression of fragments of Ure2p or fusion proteins including parts of Ure2p.

Amino Acid Sequence↗
PubMed1999

Studies on spatial orientation and posture control and changes in otolith function due to linear acceleration loading.

Otolith function is directly affected by weightlessness at the time of movement in outer space, and changes occur in the mode of response. It has been known for some time that such changes occur in the posture and gait of astronauts just after they return from a trip into space. It is thought that the cause of these changes is disuse atrophy of the antigravity muscles. However, in the present study, experimental subjects underwent repeated linear acceleration loading over a long period of time, and instability of the head and a decrease in posture control, especially in relation to the gait, were observed for the first time. To date, it has been said that the otolith function has a close relationship with ocular counter rolling. However, when the otolith organ was stimulated, the response was seen to be head instability and an irregular effect on the gait. It is surmised that these findings will facilitate future research into the otolith function under gravity-free conditions.

Acceleration↗
PubMed1999

Myelinated nerve fiber analysis of the human greater splanchnic nerve.

The purpose of the present study is to analyze the human greater splanchnic nerve in relation to aging. We adopted a new staining method which makes it possible to discriminate various structures of the nervous tissue. We examined 25 human greater splanchnic nerves from cadavers for anatomy dissection. We measured the number, area and perimeter of axons. The results reveal that: (1) there is no correlation between age and the number of axons; (2) the mean area and perimeter of axons increase with age, but not the total area and perimeter. We compared these results with those for the lesser splanchnic nerve. These morphological changes in the greater splanchnic nerve may indicate a kind of compensation through axon hypertrophy for hypofunctions in abdominal organ control.

Adult↗