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Biomedical subjects

F Sato

Publications and source records attributed to F Sato.

At least 361 records · Page 20Linked to original sources
PubMed1985

Functional reconstruction for unilateral recurrent laryngeal nerve paralysis caused by thyroid cancer.

Surgery for unilateral recurrent laryngeal nerve paralysis, which is caused by thyroid cancer, appearing within the past six months, should be aimed at improvement of the asymmetrical vocal cord and preservation of the stiffness and the mass of the vocal fold. To accomplish these aims, reconstructive surgery of the neuromuscular systems is available and it should be performed at the same time as thyroidectomy. Our surgical procedures for unilateral recurrent laryngeal nerve paralysis caused by thyroid cancer are reported along with some experimental investigations in dogs. Experimentally, muscle atrophy was prevented by neurorrhaphy or by free nerve grafting of the recurrent laryngeal nerve, although movement of the vocals cord was not recovered due to misdirected reinnervation and reduction of the end plates. In our study of functional reconstruction for unilateral recurrent laryngeal nerve paralysis, end-to-end anastomosis or free nerve grafting between the recurrent laryngeal nerve after extirpating the abductor muscle branch of this nerve was the most effective and practical method for improvement of the adductor function. Clinically reconstructive surgery was performed on five females suffering from thyroid cancer with unilateral recurrent laryngeal nerve paralysis. The abductor branch was cut selectively in four cases, followed by free nerve grafting of the ansa cervicalis and pedicle nerve muscle graft of the thyrohyoid muscle implanted in one case. Vocal cord atrophies were not observed and phonations were good in all cases six months after of operation. However, obvious adduction of the operated vocal fold at phonation was obtained only in two cases and other two cases showed slight adduction.

Adult↗
PubMed1985

Radiation sensitization of Escherichia coli B/r by 2'-chloro-2'-deoxythymidine under various irradiation conditions.

In order to elucidate the mechanism of sensitization of E. coli B/r cells to X-irradiation by 2'-chloro-2'-deoxythymidine (2'Cl-TdR), the survival curves of the cells in which 2'Cl-TdR was incorporated into DNA were obtained following X-irradiation under various conditions. The marked sensitization of E. coli cells by 2'Cl-TdR to the killing action of X-rays was observed, when E. coli cells labelled with 2'Cl-TdR were exposed to X-rays in the absence of oxygen as well as in the presence of oxygen. The sensitization factor calculated from inactivation constants from survival curves irradiated in the absence of O2 was about a half of that obtained in the presence of O2. Under the conditions where 2'Cl-TdR was not incorporated into the DNA of E. coli cells, the presence of 2'Cl-TdR in the cell suspension fluid at the time of irradiation caused no sensitization of the cells to X-irradiation. The sensitization factor for 2'Cl-TdR obtained under N2O was almost same as that obtained under N2. It was also observed that the sensitization factor obtained in the presence of glycerol at a concentration of 1 mol dm-3 under N2 was similar to that obtained in the absence of glycerol. These results indicated that the direct effect of ionizing radiation on DNA was closely associated with the sensitization of E. coli B/r cells by 2'Cl-TdR and that the radical at the C-2' position of the deoxyribose moiety in DNA produced by X-irradiation was transformed into lethal damage for E. coli cells even in the absence of O2. However, this transformation occurred more efficiently in the presence of O2 than in the absence of O2.

Dose-Response Relationship, Radiation↗
PubMed1985

Deletions into an NH2-terminal hydrophobic domain result in secretion of rotavirus VP7, a resident endoplasmic reticulum membrane glycoprotein.

Rotavirus, a non-enveloped reovirus, buds into the rough endoplasmic reticulum and transiently acquires a membrane. The structural glycoprotein, VP7, a 38-kD integral membrane protein of the endoplasmic reticulum (ER), presumably transfers to virus in this process. The gene for VP7 potentially encodes a protein of 326 amino acids which has two tandem hydrophobic domains at the NH2-terminal, each preceded by an in-frame ATG codon. A series of deletion mutants constructed from a full-length cDNA clone of the Simian 11 rotavirus VP7 gene were expressed in COS 7 cells. Products from wild-type, and mutants which did not affect the second hydrophobic domain of VP7, were localized by immunofluorescence to elements of the ER only. However, deletions affecting the second hydrophobic domain (mutants 42-61, 43-61, 47-61) showed immunofluorescent localization of VP7 which coincided with that of wheat germ agglutinin, indicating transport to the Golgi apparatus. Immunoprecipitable wild-type protein, or an altered protein lacking the first hydrophobic sequence, remained intracellular and endo-beta-N-acetylglucosaminidase H sensitive. In contrast, products of mutants 42-61, 43-61, and 47-61 were transported from the ER, and secreted. Glycosylation of the secreted molecules was inhibited by tunicamycin, resistant to endo-beta-N-acetylglucosaminidase H digestion and therefore of the N-linked complex type. An unglycosylated version of VP7 was also secreted. We suggest that the second hydrophobic domain contributes to a positive signal for ER location and a membrane anchor function. Secretion of the mutant glycoprotein implies that transport can be constitutive with the destination being dictated by an overriding compartmentalization signal.

Amino Acid Sequence↗
PubMed1985

Immunocytochemical localization of Na+, K+-ATPase in the canine choroid plexus.

To determine the localization of Na+, K+-ATPase in the choroid plexus of the canine fourth ventricle, antisera against canine renal Na+, K+-ATPase holoenzyme and the alpha and beta subunits of the enzyme were employed and the distribution of reaction product examined at the light and electron microscopic level by means of the peroxidase-antiperoxidase immunohistochemical method. In the choroidal epithelial cells, antigenic sites were restricted to the outer surface of the apical plasmalemma, including the membranes of the microvilli. No reaction product was detected in the cytoplasm or along the lateral and basal plasmalemma. These findings strengthen the hypothesis that the apical border of the choroidal epithelial cell plays an important role in cerebrospinal fluid secretion as a result of active transport mediated by Na+, K+-ATPase.

Animals↗
PubMed1985

Promoting effect of the new chymotrypsin inhibitor FK-448 on the intestinal absorption of insulin in rats and dogs.

FK-448 is a potent and specific inhibitor of chymotrypsin, which enhances the intestinal absorption of insulin in rats and dogs resulting in a decrease in blood glucose levels in these animals. In dogs, the immunoreactive insulin (IRI) level of plasma rose proportionally to the decrease in blood glucose level. From in-vitro data, insulin was inactivated by pancreatic enzymes or the supernatants of intestine or liver homogenates. FK-448 suppressed the digestion of insulin by pancreatic enzymes and its enhancement of the intestinal absorption of insulin was found to be related to its inhibition of digestive enzymes, especially chymotrypsin.

Animals↗
PubMed1985

Rotavirus neutralizing protein VP7: antigenic determinants investigated by sequence analysis and peptide synthesis.

The rotavirus neutralizing antigen, VP7, is a 37,000-molecular-weight glycoprotein which is a major component of the outer shell of the virion. The amino acid sequence of VP7 for strain S2 (human serotype 2) and Nebraska calf diarrhea virus (bovine serotype) has been inferred from the nucleic acid sequence of cloned copies of genomic segment nine. Comparison of the amino acid sequences of these two VP7 proteins with those already determined for other rotavirus strains reveals extensive sequence conservation between serotypes with clusters of amino acid differences sited predominantly in hydrophilic domains of the protein. Six peptides have been synthesized that span the hydrophilic regions of the molecule. Antisera to these peptides both recognize the respective homologous peptides in a solid-phase radioimmunoassay and bind to denatured VP7 in a Western blot. However, none of the antisera either recognize virus or exhibit significant neutralizing activity, indicating that these peptide sequences are not available on the surface of the virus.

Amino Acid Sequence↗
PubMed1984

Immunohistochemical localization of Na+, K+-ATPase in the choroid plexus.

To determine if canine and rat choroid plexus Na+,K+-ATPase can be localized by immunoperoxidase staining after fixation and embedding, we prepared rabbit antiserum to purified canine kidney medulla Na+,K+-ATPase. When sodium dodecylsulfate polyacrylamide electrophoretic gels of purified canine kidney Na+,K+-ATPase and canine kidney microsomes were treated with antiserum followed by [125I]protein A and autoradiography, the canine microsomes and purified Na+,K+-ATPase showed a prominent radioactive band coincident with the alpha-, beta- and gamma-subunits of the purified canine kidney enzyme. When the rabbit immunoglobulin that was purified from the Na+,K+-ATPase antiserum through DEAE-cellulose ion exchange chromatography was used for immunoperoxidase staining of the choroid plexus fixed with Bouin's fixative, intense immunoreactive staining was present on the epithelial cells of both choroid plexuses but was not found in the tissue around the vessel. The staining was especially confined to apical surfaces of the epithelial cells. The same procedure was performed in the canine kidney, and immunostaining was obtained in the tubules where Baskin and Stahl described the enzyme localization. No staining was seen with pre-immune serum of the normal rabbit. We concluded that both the canine and rat choroid plexus are rich in Na+,K+-ATPase, which plays an important role in cerebrospinal fluid (CSF) secretion.

Animals↗
PubMed1984

Computed tomographic evolution of post-traumatic subdural hygroma in young adults.

The authors report on two cases of post-traumatic subdural hygroma that were encountered in young adults. Serial computed tomograms were taken immediately following trauma and for more than 4 weeks thereafter. In the case of a 28-year-old man with a skull fracture, an initial CT scan revealed a thin crescentic subdural collection in the right frontal area. A successive CT scan on the 36th postoperative day revealed developed subdural hygroma, and the CSF-like fluid was surgically evacuated. In the second case, involving an 18-year-old man, a very thin bifrontal subdural collection was found on the initial CT scan, and on the 15th post-traumatic day CT scan demonstrated a bifrontal subdural hygroma. No surgical treatment was carried out, and the follow-up CT scan on the 29th post-traumatic day demonstrated no change in size. The two young patients were slightly symptomatic during the period involved, and the repeat unenhanced CT scans showed subdural lesions of less than brain density, even in the chronic stage.

Adolescent↗
PubMed1984

The localization of motoneurons innervating the canine pharyngeal constrictor muscles in the posterior larynx by the fluorescent double-labeling technique.

The localization of motoneurons innervating the canine pharyngeal constrictor muscles in the posterior larynx, i.e., the hyopharyngeal muscle (HP), the thyropharyngeal muscle (TP) and the cricopharyngeal muscle (CP), was investigated by the fluorescent labeling technique. Labeled cells were found in the rostral portion of the ipsilateral nucleus ambiguus. The rostral ends of these cell columns were located at nearly the same level. The caudal ends of the HP cell column and the TP cell column were also located at nearly the same level. However, the CP cell column was elongated a little more caudally. The HP cells and the TP cells were intermingled in the dorsal part of the nucleus. The CP cells were mainly located in the ventral part of the nucleus. No double-labeled cells were detected.

Animals↗
PubMed1984

Vocal rehabilitation by tracheogastric shunt method after pharyngolaryngoesophagectomy for malignancy.

After pharyngolaryngoesophagectomy had been performed to remove a malignant tumor, a shunt was created between the elevated gastric tube and the trachea for vocal rehabilitation in two patients. By covering the tracheostoma, the patients were able to produce a substituted voice without any reflux. However, strange vibrations of the gastric tube slightly disturbed the intelligibility of the shunt voice.

Carcinoma, Squamous Cell↗
PubMed1984

Ultrastructure of the wall of the Dandy-Walker cyst. A case report.

The ultrastructure of the wall of the Dandy-Walker cyst has been described rarely. A boy aged 2 years was confirmed clinically, neuroradiologically, and operatively as having a Dandy-Walker cyst in the posterior fossa. The cyst wall obtained during surgery consisted of an outer arachnoid cell layer, intermediate interwoven neurological strands, and an inner layer of cells which lacked the characteristic appearance of ependyma. An unusual finding was a small, buried island of ependymal cells in the intermediate layer of the neuroglial tissue. Ultrastructural study of the cyst wall provides a better understanding of the pathogenesis of the Dandy-Walker syndrome.

Arachnoid↗
PubMed1984

Nucleus ambiguus motoneurons innervating the canine intrinsic laryngeal muscles by the fluorescent labeling technique.

The localization of motoneurons innervating the canine intrinsic laryngeal muscles was investigated by the fluorescent labeling technique. Labeled cells were found in the ipsilateral nucleus ambiguus. The most rostral labeled neurons for the cricothyroid muscle, the posterior cricoarytenoid muscle, the thyroarytenoid muscle, and the lateral cricoarytenoid muscle were found at progressively more caudal levels, respectively, within the nucleus ambiguus. The rostral tip of the arytenoid muscle cell column was at the same level as the lateral cricoarytenoid muscle cell column. The cells labeled from the cricothyroid muscle occupied the ventral part of the nucleus at the rostral level of the nucleus. At the middle level of the nucleus, the cells from the posterior cricoarytenoid muscle occupied the ventral part of the nucleus and the cells from the thyroarytenoid muscle, the lateral cricoarytenoid muscle and the arytenoid muscle occupied the dorsal part of the nucleus. The existence of double-labeled cells which innervated both thyroarytenoid muscle and lateral cricoarytenoid muscle was detected.

Animals↗