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Biomedical subjects

K Omori

Publications and source records attributed to K Omori.

At least 145 records · Page 8Linked to original sources

[A case of primitive neuroectodermal tumor from rib].

Primitive Neuroectodermal Tumor (PNET) is a small round cell malignancy arising in bone and soft tissue. With the progress of immunohisto-chemical and ultrastructural studies, the tumor has getting attention. We report a rare case of PNET arising from rib. A 19-year-old man was admitted to our hospital complaining of chest and back pain. The tumor arised from 5th rib and en bloc resection was performed. Pathological diagnosis was PNET. After the operation, he is doing well, except being treated with chemotherapy (T9-protocol).

Adult↗

Anticus-lateralis muscle suturing. Treatment of recurrent nerve paralysis.

We have devised a new surgical method that sutures the cricothyroid (anticus) muscle to the paralyzed lateral cricoarytenoid (lateralis) muscle for the dynamic reconstruction of the larynx. Because this method achieved remobilization of the paralyzed vocal cord in dogs, we applied it to seven patients with unilateral recurrent laryngeal nerve paralysis (four patients had postsurgical paralysis and three patients had idiopathic paralysis). We obtained the following satisfactory results: (1) vocal cord tension and voice quality improved in all patients, and (2) in four patients, remobilization of the paralyzed vocal cord was obtained. We believe that this surgical method could serve as a new dynamic method of reconstruction for the treatment of unilateral recurrent laryngeal nerve paralysis.

Anastomosis, Surgical↗

Remobilization of paralyzed vocal cord by anticus-lateralis muscle suturing.

A new method of dynamic reconstruction by suturing the cricothyroid (anticus) and the lateral cricoarytenoid (lateralis) muscles was devised for the treatment of unilateral recurrent laryngeal nerve paralysis. Eighteen adult dogs underwent this surgical procedure after sectioning a recurrent laryngeal nerve. Immediate postoperative observations revealed a marked increase in tension of the paralyzed vocal cords and remobilization to the median line of 17 of 18 dogs. More than 4 months later, fiberscopic examination revealed a satisfactory adduction of the cords. Electrophysiologic and histologic examination showed reinnervation of the affected lateralis muscle by the external branch of the superior laryngeal nerve. The clinical applications of this surgery may serve as a dynamic reconstruction for unilateral recurrent laryngeal nerve paralysis.

Animals↗

Nucleotide sequence of the Serratia marcescens threonine operon and analysis of the threonine operon mutations which alter feedback inhibition of both aspartokinase I and homoserine dehydrogenase I.

The nucleotide sequence of the Serratia marcescens threonine operon (thrA1A2BC) was determined. Three long open reading frames were identified; these open reading frames code for aspartokinase I (AKI)-homoserine dehydrogenase I (HDI), homoserine kinase, and threonine synthase, in that order. The predicted amino acid sequences of these enzymes were similar to the amino acid sequences of the corresponding enzymes in Escherichia coli. The AKI-HDI protein is apparently a tetramer composed of monomer polypeptides that are 819 amino acids long. A deletion analysis revealed that the central and C-terminal region was responsible for threonine-resistant HDI activity, a monomeric fragment extending from the N terminus to residue 306 was responsible for threonine-resistant AKI activity, and an N-terminal portion containing 468 residues was responsible for threonine-sensitive AKI activity. The thrA(1)1A(2)1 and thrA(1)5A(2)5 mutations of threonine-excreting strains HNr21 and TLr156, which result in the loss of threonine-mediated feedback inhibition of both AKI activity and HDI activity, cause single amino acid substitutions (Gly to Asp at position 330 and Ser to Phe at position 352, respectively) in the central region of the AKI-HDI protein. The thrA1+A(2)2 mutation of strain HNr59, which results in a threonine-sensitive AKI and a threonine-resistant HDI, also causes a single amino acid substitution (Ala to Thr at position 479).

Allosteric Regulation↗

Role of serine 352 in the allosteric response of Serratia marcescens aspartokinase I-homoserine dehydrogenase I analyzed by using site-directed mutagenesis.

Aspartokinase I and homoserine dehydrogenase I (AKI-HDI) from Serratia marcescens Sr41 are encoded by the thrA gene as a single polypeptide chain. Previously, a single amino acid substitution of Ser-352 with Phe was shown to produce an AKI-HDI enzyme that is not subject to threonine-mediated feedback inhibition. To determine the role of Ser-352 in the allosteric response, the thrA gene was modified by using site-directed mutagenesis so that Ser-352 of the wild-type AKI-HDI was replaced by Ala, Arg, Asn, Gln, Glu, His, Leu, Met, Pro, Thr, Trp, Tyr, or Val. The Thr-352 and Pro-352 replacements rendered AKIs sensitive to threonine. The Tyr-352 and Asn-352 substitutions led to activation, rather than inhibition, of AKI by threonine. The other replacements conferred threonine insensitivity on AKI. The threonine sensitivity of HDI was also changed by the amino acid substitutions at Ser-352. The HDI carried by the Tyr-352 mutant AKI-HDI was activated by threonine. Single amino acid replacements at Ser-352 by Ala, Asn, Gln, His, Phe, Pro, Thr, or Tyr were introduced into truncated AKI-HDIs containing the AKI and the central regions. The AKI activity of the truncated AKI-HDI containing the first 468 amino acid residues was sensitive to threonine, and introduction of the amino acid replacements did not alter the threonine sensitivity of the AKI. Another truncated AKI-HDI containing the first 462 amino acid residues possessed threonine-resistant AKI, whereas the substitutions of Ser-352 with Ala and Pro rendered AKI sensitive to threonine. The replacement of GIn-351 with Phe activated AK1 of the truncated AKI-HDI in the presence of L-threonine. These findings suggest that Ser-352 of the central region of AKI-HDI is possibly a key residue involved with the allosteric regulation of both AKI and HDI activities.

Allosteric Regulation↗

[The partial resection of lung with MULTIFIRE ENDO GIA 30 under the thoracoscopy].

MULTIFIRE ENDO GIA 30 was a newly auto suture developed by US surgical c.o., A 27-year-old man was admitted for right spontaneous pneumothorax in our hospital. We performed the partial resection of lung with this new auto suture under the thoracoscopy. Condition of patient after operation was very good, and he could discharge in short hospitalization. We concluded that this new auto suture was entirely reversible and safety.

Adult↗

[Simultaneous operation of Cabrol's operation and sternal turnover with rectus abdominal flap].

We performed simultaneous operation of sternal turnover and Cabrol operation for a 28-year-old man, who had 3rd grade funnel chest and annuloaortic ectasia with 3rd grade aortic regurgitation. We think when both annuloaortic ectasia and funnel chest are indicated for operation, simultaneous operation is to be considered and the combination of Cabrol operation and sternal turnover with rectus abdominal flap is the best procedure.

Adult↗

[A case report of mediastinal teratoma complicated with cardiac tamponade].

A 10-year-old Japanese boy was admitted to our hospital with complaints of the sudden and severe chest pain having occurred when he caught a ball on his chest. A chest X-ray film and MRI made a diagnosis of cardiac tamponade caused by perforation into the pericardial sac of a mediastinal teratoma and pericardial drainage was carried out. Pericardial effusion showed cloudy yellow and CA 19-9 level in the effusion was 6, 538.2 U/ml. The tumor was extirpated after recovery of his general condition. The tumor was consisted of solid material (5 x 6 x 3 cm) and of cystic part (4 x 6 x 0.8 cm) involving of viscous yellowish fluid. Microscopic sections showed ulcer with bleeding, granulation and pancreatic tissue. Histopathological diagnosis was benign mature teratoma. Including this case, fourteen cases of mediastinal teratomas with cardiac tamponade have been reported and this is the youngest case. Pancreatic tissue were observed histopathologically in most cases and it was thought that autodigestion by digestive enzyme from pancreas was major cause of perforation of the tumor into the pericardial sac.

Cardiac Tamponade↗

Quantitative immunogold localization of Na, K-ATPase along rat nephron.

Ultrastructural localization of Na, K-ATPase alpha-subunit along rat nephron segments was investigated quantitatively by immunogold electron microscopy on LR-White ultrathin sections using affinity-purified antibody against alpha-subunit of the enzyme. Ultrathin sections were incubated with the antibody at a saturation level and the number of gold particles bound per micron of the plasma membrane (particle density) of the tubular epithelial cells from the proximal tubule to the collecting duct was determined. In all the tubular epithelial cells, gold particles were located exclusively on the basolateral surface, and no significant binding of gold particles to the apical surface was observed. Distribution of gold particles on the basolateral membranes was quite heterogeneous; lateral membranes and infolded basal membranes were highly labeled, whereas the basal membranes which are in direct contact with the basal lamina were scarcely labeled. The average particle density on the basal surface was highest in the distal straight tubule cells (11.4 units), very high in the distal convoluted tubule cells (9.8 units), intermediate in the proximal tubule cells (3.3 units), in the connecting tubule cells (4.3 units), and in the principal cells of the collecting duct (5.6-3.8 units), low in the thin limb of Henle's loop (1.0 unit), and at the control level in the intercalated cells in the connecting and collecting duct. The relative number of gold particles/mm nephron segment and the relative number of gold particles in the various nephron segments were calculated using quantitative morphological data. The estimated distribution profile of the former was in good agreement with the Na, K-ATPase activity profile in rat nephron, which was determined biochemically with a microenzymatic method.

Animals↗

Quantitative immunoelectron microscopic localization of Na, K-ATPase alpha-subunit in the epithelial cells of rat vestibular apparatus.

Na, K-ATPase was quantitatively localized in the epithelial cells of rat vestibular apparatus such as macula utriculi, macula sacculi and crista ampullaris. Immunogold localization method was carried out at the saturation level of antibody using an affinity purified antibody against the alpha-subunit of rat kidney Na, K-ATPase. Numerous gold particles were found on the basolateral membrane of the dark cells, a small number of gold particles were found on the basolateral membrane of the transitional epithelium cells and hair cells, but the luminal surface membranes of the hair cells, transitional epithelium cells, planum semilunatum cells and dark cells were rarely labeled by gold particles. Significance of the abundant localization of Na, K-ATPase on the basolateral surface of the dark cells in the production of endolymph was discussed.

Animals↗

Analysis of the mutant proBA operon from a proline-producing strain of Serratia marcescens.

The nucleotide sequence of the proBA operon from a proline-hyperproducing mutant of Serratia marcescens was determined. Two base substitutions were found: one in the proB structural gene, coding for gamma-glutamyl kinase (GK), and a second one in the promoter region of the operon. The former base substitution led to a change of the predicted amino acid at position 117 from an alanine to a valine in GK. This mutation rendered GK 700-fold less sensitive to proline-mediated feedback inhibition than the wild-type enzyme. The other base substitution, a transversion from a G-C to an A-T, was located in the spacer region between the '-35' and '-10' sequences of the promoter, and it increased the transcriptional activity of this operon fourfold. Both these two base substitutions, which were acquired at the step of selecting mutants resistant to a toxic proline analogue, 3,4-dehydroproline, confer upon cells a high proline productivity and an increased osmotolerance.

Amino Acid Sequence↗

Different patterns of protein kinase C redistribution mediated by alpha 1-adrenoceptor stimulation and phorbol ester in rat isolated left ventricular papillary muscle.

1. In rat left ventricular papillary muscle, phenylephrine, an alpha 1-adrenoceptor agonist, had a staurosporine-sensitive positive inotropic effect and increased the particulate-associated protein kinase C (PKC) activity without significant changes in total PKC activity or in cytosolic Ca2+/phospholipid-independent kinase (PKI) activity. 2. A PKC stimulant, phorbol 12,13-dibutyrate (PDBu), decreased contractility and slightly increased PKC activity in the particulate fractions, with a marked decrease and increase in total PKC and PKI activities, respectively. 3. The PDBu-induced negative inotropic response was attenuated by two protease inhibitors, leupeptine and a microbial peptide isolated from Aspergillus japonicus (E-64), which are known to inhibit the conversion of particulate-associated PKC to PKI. 4. Such differences in the patterns of PKC redistribution, i.e. marked increases in particulate PKC and cytosolic PKI activities caused by phenylephrine and PDBu, respectively, may account for the opposite inotropic effects of PKC stimulation by an alpha 1-agonist and a phorbol ester.

Adrenergic alpha-Agonists↗

Experimental studies on the viscoelasticity of the vocal fold.

Viscoelasticity of the vocal fold was assessed by analyzing the stress-strain relationship under several experimental conditions. The stiffness increased with greater tension of the vocal fold. Marked differences in the mechanical properties were noted between the "body" and the "cover" of the vocal fold, especially when tension was applied. Contraction of the thyroarytenoid muscle tended to make the vocal fold less stiff and more viscous. Dry vocal-fold mucosa was associated with greater stiffness. Submucosal injection of saline solution to simulate edema increased the stiffness and viscosity of the vocal fold.

Animals↗

Mechanical properties of the vocal fold. Stress-strain studies.

The viscoelasticity of the vocal and ventricular folds was experimentally assessed by analyzing the stress-strain relationships obtained using a newly developed measuring system. The degree of stiffness of the mid-membranous portion of the vocal fold was less than that near the anterior commissure or the vocal process. The ventricular fold was much less stiff and significantly more viscous than the vocal fold. At the membranous portion of the vocal fold, the degree of stiffness was less and that of viscosity greater at 2 mm above and below the free margin than at the free margin itself.

Adult↗

Ultrastructural localization of Na+, K(+)-ATPase in the exorbital lacrimal gland of rat.

Ultrastructural localization of Na+, K(+)-ATPase in the exorbital lacrimal gland of rat was investigated quantitatively by protein A-gold technique. Na+, K(+)-ATPase was purified from the rat kidney, and anti-holo Na+, K(+)-ATPase antibody was obtained from the rabbit by injecting the purified enzyme. A specific antibody against the alpha-subunit of Na+, K(+)-ATPase was affinity purified. Immunoblot analysis revealed that the antibody bound specifically to the alpha-subunit of Na+, K(+)-ATPase of the lacrimal gland. Rats were fixed by perfusion with 4% paraformaldehyde containing 1% glutaraldehyde, and the lacrimal glands were embedded in LR White resin. Ultrathin sections were incubated with affinity purified antibody against the alpha-subunit of Na+, K(+)-ATPase, and then with protein A-gold complex. The sections were observed under an electron microscope. Light microscopy with silver enhancement procedure revealed that Na+, K(+)-ATPase was located mainly on the basal region of the cells of intralobular and interlobular ducts. Quantitative immunoelectron microscopic analysis showed that gold particles were found on the basolateral surfaces of the interlobular and intralobular ducts cells and on the basolateral surface of the acinar cells, whereas no significant binding was observed on any part of the apical surfaces of these cells. Labeling density of gold particles was highest on the basolateral surface of the interlobular duct cells, secondarily highest on the basolateral surface of the intralobular duct cells, and lowest on the basolateral surface of the acinar cells. The distribution pattern of Na+, K(+)-ATPase in the acinar cells and the duct cells suggest that this enzyme may play an important role in primary secretion and in determining the composition of electrolytes in the final secretion, respectively.

Animals↗

[Treatment of pericardial cyst under thoracoscopy].

Thoracoscopic therapy was carried out on two cases of pericardial cyst. The first patient was a 24-year-old male. An abnormal shadow on a chest X-ray was pointed out at a regular checkup. Thoracoscopy was carried out under the local anesthesia and a thin-walled cyst was discovered. The cyst was punctured and serous fluid was aspirated. Then, several biopsy specimens were obtained from the cyst wall, a pathological diagnosis of the cyst was made as a pericardial cyst. One year after the thoracoscopy, no abnormal shadow is observed on chest X-ray. The second patient was a 26-year-old male. It was also discovered that he had an abnormal shadow on a chest X-ray at a regular medical checkup. Since a solid mass couldn't be completely denied, thoracoscopy was carried out in preparing for thoracotomy under the general anesthesia. The cyst observed between SVC and the azygos vein, and serous fluid was aspirated form the cyst. Following this, the cyst wall was biopsied and opened. Since no cases of malignant pericardial cysts have been reported, an operation is not usually required for these patients. We suggest that thoracoscopy is very useful tool for the final diagnosis and therapy of pericardial cyst because this method is easily carried out under local anesthesia.

Adult↗