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Biomedical subjects

N Satoh

Publications and source records attributed to N Satoh.

At least 217 records · Page 12Linked to original sources
PubMed1994

[Experience with surgery for metachronous double cancer originated from thymus and lung].

A case with thymic cancer who developed pulmonary cancer ten years after the initial surgery was reported. A 50-year-old man was admitted to our hospital due to SVC syndrome. Chest X-ray examinations including venogram showed a mass lesion at the superior mediastinum. The patient underwent surgical removal and reconstruction of SVC, followed by radio-chemotherapy. The histologic diagnosis was thymic squamous cell carcinoma. He was admitted to our hospital again ten years after the initial surgery under the diagnosis of pneumonia. Bronchoscopic examination revealed nodular lesions at the right upper lobe bronchus and lower lobe bronchus, those lesions were diagnosed with squamous cell carcinomas cytologically. Right pneumonectomy was performed and the diagnosis was confirmed pathologically. Postoperative course was uneventful as of 10 months after the operation. It was concluded that this case showed metachronous double cancer of the thymus and the lung, as well as synchronous multiple bronchogenic carcinomas, which, to our knowledge, has never been reported yet.

Carcinoma, Squamous Cell↗
PubMed1993

Pituitary adenomas of patients with acromegaly express thyrotropin-releasing hormone receptor messenger RNA: cloning and functional expression of the human thyrotropin-releasing hormone receptor gene.

We cloned a human thyrotropin-releasing hormone receptor (TRH-R) gene and its pituitary cDNA, and examined whether TRH-R mRNA may be expressed and function in the GH-secreting pituitary adenomas of patients with acromegaly. The human TRH-R consists of 398 amino acids and is a member of the G protein-coupled receptor family. The gene has a single intron in the coding sequence. An addition of TRH caused an obvious increase in intracellular calcium concentration in chinese hamster ovary cells expressing this receptor. Although highly homologous to the rat and mouse TRH-Rs, the human TRH-R has several differences in the carboxyl-terminal structure. The sequence and functioning analyses showed the same expression of TRH-R mRNA in the pituitary adenomas as that in the normal pituitaries, indicating that 1) some adenomas of patients with acromegaly express an intact and functional TRH-R, and that 2) the paradoxical response of GH secretion to TRH found in the patients might be a direct effect of TRH on TRH-R expressed in the adenoma.

Acromegaly↗
PubMed1993

A complementary DNA for an ascidian embryonic nuclear antigen Hgv2 encodes a protein closely related to the amphibian histone-binding protein N1.

We have isolated and sequenced a cDNA clone encoding an ascidian embryonic nuclear protein, Hgv2. An insert about 2 kb long covered almost the entire length of 2.3-kb Hgv2 mRNA. The amino acid sequence of Hgv2 deduced from the cDNA sequence showed that this protein is related to the amphibian karyophilic histone-binding protein N1, which is thought to be involved in nucleosome assembly. Homology between these two proteins is evident from their extremely similar amino acid compositions and hydropathy profiles. In addition, Hgv2 protein has sequences strikingly similar to the nuclear targeting signal of N1. This is therefore the first report of molecular cloning of a homologue of N1 in non-amphibian species. Putative histone-binding domains of N1 are composed of two acidic residue-rich clusters. Hgv2 polypeptide contains two highly acidic regions, but amino acid sequences of the regions are not conserved. Since Hgv2 protein exists in nuclei of every embryonic cell but disappears from nuclei of metamorphosed juvenile tissues, this protein may function as a nucleosome assembly factor during rapid embryonic cell divisions.

Amino Acid Sequence↗
PubMed1993

Site-directed mutagenesis of the putative active site residues of 3C proteinase of coxsackievirus B3: evidence of a functional relationship with trypsin-like serine proteinases.

Picornavirus 3C proteinases (3Cpro) are cysteine proteinases but recent sequence analyses have shown that they are related to trypsin-like serine proteinases. Two models of 3Cpro structure have been presented. Both models indicate that residues His40 and Cys147 are members of the catalytic triad but the models differ in the designation of the third member of the catalytic triad, which is assigned as either Glu71 or Asp85. To test the importance of these four residues in the catalytic activity of 3Cpro of coxsackievirus B3, a member of the enterovirus subgroup of the picornavirus family, single amino acid substitutions were introduced at each of the four sites. All of these mutations resulted in the reduction or inactivation of autocatalytic cleavage of the 3C precursor protein expressed in Escherichia coli, suggesting that all of these residues are essential for the proteolytic reaction. The substitution of Cys147 with Ala abolished 3Cpro activity while the mutant in which Cys147 was replaced with Ser retained reduced proteolytic activity both in cis and in trans. Our results strongly support the proposal that Cys147 of 3Cpro functions as a nucleophile analogous to Ser195 of trypsin-like serine proteinases.

3C Viral Proteases↗
PubMed1993

Evaluation of oral anticoagulant therapy by measuring plasma prothrombin fragment 1 + 2.

To assess the degree of haemostatic system activation, plasma levels of prothrombin fragment 1 + 2 (F1 + 2), a direct indicator for thrombin generation in vivo, were measured in 49 patients with thrombotic disease undergoing long-term warfarin therapy (Thrombotest values < or = 40%). In these patients, vitamin K dependent coagulation factors (factors II, VII, IX and X) were decreased together with the anticoagulant proteins C and S, but the mean plasma concentration of F1 + 2 was significantly decreased compared with 48 healthy subjects. In warfarin-treated patients, F1 + 2 was positively correlated with the Thrombotest value, factors II, VII, IX and X. When analysed according to the intensity of anticoagulation, patients with Thrombotest values less than 30% showed a significant decrease in F1 + 2, but the mean F1 + 2 level was normal in patients with Thrombotests higher than 30%. These findings indicate that long-term oral anticoagulant therapy suppresses thrombin generation approximately in parallel to the decrease in coagulation factors, and levels of F1 + 2 lower than healthy subjects are observed when Thrombotest values are less than 30%.

Administration, Oral↗
PubMed1993

Novel genes expressed differentially in ascidians with alternate modes of development.

We have used a subtractive procedure to isolate cDNA clones encoding genes expressed differentially in ascidian species with alternate modes of development. The ascidians used in this study were Molgula occulta, which develops a tailed (urodele) larva, and Molgula occulta, which develops a tailless (anural) larva. Two of the identified clones, Uro-2 and Uro-11, are described. Southern blots show that the Uro-2 and Uro-11 genes are present in both species, but the corresponding mRNAs are expressed preferentially in the urodele species. In situ hybridization showed that Uro-2 and Uro-11 transcripts accumulate in small oocytes during oogenesis. The maternal Uro-2 and Uro-11 transcripts were distributed throughout the oocyte cytoplasm. Transcript concentrations declined during vitellogenesis, but mature eggs still contain detectable levels of Uro-2 and Uro-11 mRNA. After fertilization, the maternal Uro-2 and Uro-11 transcripts were localized in the ectoplasm of uncleaved zygotes and mostly entered the ectoderm cells during cleavage. The Uro-2 gene appears to produce only maternal transcripts. In contrast, the Uro-11 gene may also produce zygotic transcripts, which accumulate between gastrulation and neurulation in posterior epidermis, neural and tail muscle cells. Zygotic expression of the Uro-11 gene was not detected in embryos of the anural species. The deduced amino acid sequences of the Uro-2 and Uro-11 cDNAs suggest that they encode novel basic proteins with distinctive structural features. The predicted Uro-2 protein contain, a leucine zipper motif, suggesting that it may dimerize with another protein. The predicted Uro-11 protein contains a nuclear localization signal, a region with similarity to part of the DNA-binding motif in the bacterial histone-like HU and IHF proteins, 12 repeats of the proposed DNA-binding motif S(T)PXX, and a potential zinc finger of the C6 or C6H2 class, suggesting that it may be a DNA-binding protein. The Uro-2 and Uro-11 proteins are candidates for regulatory factors involved in the evolutionary transition from urodele to anural development.

Amino Acid Sequence↗
PubMed1993

[Changes in human spontaneous otoacoustic emissions with contralateral acoustic stimulation].

According to current cochlear concepts, spontaneous otoacoustic emissions (SOAEs) are thought to be the product of outer hair cell (OHCs) movement. Furthermore, efferent neurofibers from the olivocochlear bundle primarily innervate OHCs. Thus, we designed this investigation to determine changes in SOAE under conditions of contralateral acoustic stimulation. Fouty-two normal ears of 34 subjects with uni- or bilateral SOAEs were examined. The sound pressure level (SPL) of SOAE was measured 3 times in each subject and was initially averaged. The white noises of 30 or 40dBSPL, believed not to affect the other side, were then loaded contralaterally and the SPL of SOAEs were measured and compared with the non-loaded data. The SPL of single SOAEs were actually suppressed with 40dBSPL stimulation while the SPL of multiple SOAEs showed typical changes. Interestingly, no significant suppression of SOAEs was noticed under conditions of contralateral acoustic stimulation of the impaired ear. These data suggest that contralateral acoustic stimulation could affect OHC function via the olivocochlear bundle.

Acoustic Stimulation↗
PubMed1993

Phylogenetic position of Acoel turbellarians inferred from partial 18S rDNA sequences.

Primitive platyhelminths, especially Acoel turbellarians, are thought to be key to understanding the origin and evolution of metazoa. In order to infer their phylogenetic position within the phylum Platyhelminths, we determined and compared the complete nucleotide sequence of a region of about 750 base pairs in the central part of an 18S rDNA for ten turbellarians, including two species of the group Acoela, six species of the group Polycladida, and two species of the group Tricladida. The deduced phylogenetic tree suggests that the three groups examined form discrete and separate entities. In addition, the tree suggests an earlier emergence of the Acoel turbellarians than the other platyhelminths. This animal may not be derived by means of secondary reduction from advanced acoelomates but may be nearest to its metazoan ancestors.

Animals↗
PubMed1993

Molecular phylogeny inferred from sequences of small subunit ribosomal DNA, supports the monophyly of the metazoa.

Recent studies of molecular phylogeny based upon comparisons of the partial nucleotide sequences of 18 and 28S rRNAs have suggested that the metazoa are polyphyletic, i.e., that diploblasts (poriferans, cnidarians, ctenophores, and placozoans) and triploblasts form two separated monophyletic units. In order to examine this hypothesis, we determined almost the complete sequences of small subunit (18S-like) rDNA for two poriferans and a ctenophore. Phylogenetic comparisons of the sequences, together with those of a cnidarian, triploblasts and other eukaryotes, supported the monophyly of the metazoa. Among the diploblasts, the ctenophore showed some similarities to the poriferans.

Animals↗
PubMed1993

[The background of foreign patients with pulmonary tuberculosis and investigation of treatment results].

This study focuses on the investigation of 35 foreign patients diagnosed as having pulmonary tuberculosis and treated at National Chiba-Higashi Hospital and the Chiba Anti-Tuberculosis Association between 1987 and 1991. All of the patients had lived in Japan less than five years. A large number of the patients were in their 20s. The chest X-rays of 24 cases (70%) revealed cavitary and sputum smear cultures for Mycobacterium tuberculosis were positive in 27 cases (77%). Many patients were in moderately advanced stages of the disease, becoming ill soon after their arrival in Japan, and being diagnosed symptomatically. Among the 35 cases, eight cases failed to finish treatment. Of those failing to finish, six were female and two were male. The results of sputum smear cultures of the patients failing to complete treatment revealed four cases that tested positive. Among those cases failing to complete treatment, four patients discharged themselves, three patients stopped during out-patient treatment, and one patient had to return to her home country because of a legal problem. A total of 14 patients were illegal immigrants: three of them failed to complete treatment because of their illegal status, and two of them due to unspecified reasons.

Adolescent↗
PubMed1993

[Two cases of M. avium complex infection presenting as solitary pulmonary nodule].

Case 1 was a 75-year-old woman. Her chest X-ray showed a 3 cm solitary nodule in the right S4, and biopsy obtained by fiberoptic bronchoscopy revealed epithelioid cell granuloma. Four weeks later, Mycobacterium avium complex (MAC) was detected on culture of the bronchial lavage fluid. She was treated with INH, RFP and EB for 12 months and recovered with no relapse. Case 2 was a 75-year-old man with mild diabetes mellitus and hypertension. Chest X-ray showed a 4 cm solitary nodule in the right S9. Percutaneous pulmonary aspiration revealed numerous acid-fast bacilli on smear, and he was treated with INH, RFP and EB. Culture proved M. avium complex. The patient was unable to continue his medications because of gastrointestinal side effects, so right lower lobectomy was performed. Cases of M. avium complex infection presenting as solitary pulmonary nodule are very rare. We found only 12 reported cases in Japan and in other countries. The most usual site of cavitary lesions in M. avium complex infections is both upper lobes, in contrast to the relatively even distribution of solitary pulmonary nodules of the 14 cases (12 reported cases and our 2 cases).

Aged↗
PubMed1993

[Investigation of self-discharged patients of pulmonary tuberculosis].

This study investigates 27 cases in which the patients left hospital care without permission for personal reasons. These patients were classified as "self-discharged patients". Each of the patients had been diagnosed as having pulmonary tuberculosis, and were receiving treatment at the National Chiba Higashi Hospital during the period from January 1988 to July 1991. Disease was in an advanced stage in each of the patients when admitted: all sputum examinations were positive and chest roentgenograms revealed cavities in 26 patients. In addition to pulmonary tuberculosis, the patients were also diagnosed has having a variety of other medical complications such as diabetes mellitus, gastric ulcers and liver disease. Many of them were unemployed or were day labors. Reasons attributed to patients self-discharge from the hospital included repetition of alcohol drinking and unauthorized outings. At the time patients chose to leave hospitalization 11 cases checked positive for sputum examinations, and 16 cases never returned to complete therapy. Many of them were rated as high risk patients for pulmonary tuberculosis because they had no immediate family, did not own a residence or have regular employment thus economic and psychological conditions were very low. There is a high possibility that these individuals will suffer pulmonary tuberculosis relapse and become infectious bacteria carriers. It is important that such patients be hospitalized long enough to receive adequate treatment to prevent then from becoming infectious carriers and spreading disease.

Adolescent↗
PubMed1993

[Effect of hemodilutional autotransfusion on coagulative-fibrinolytic dynamics and metabolic response].

We studied the effect of hemodilutional autotransfusion on coagulative-fibrinolytic dynamics and metabolic response. Hemodilutional solutions used were Dextran-40 (group A) and Salin-HES (group B). The activated partial thromboplastin time (APTT) immediately after hemodilution was prolonged in both groups. Prothrombin time (PT) and hepaplastin decreased significantly, and a remarkable variation was observed particularly in group A. The results suggest that effect on fibrinolytic dynamics is not exerted in either group because antithrombin-III (AT-III) and fibrinogen decreased significantly, while fibrinogen degradation products (FDP) are within normal ranges, and plasminogen as well as alpha 2-plasmin inhibitor (alpha 2-PI) decreased significantly. On the other hand, all other parameters such as lactic acid level, pyruvic acid level in blood, lactic acid pyruvic acid ratio, and blood glucose level were elevated during surgery, but no difference was observed regarding these parameters between the two groups.

Adult↗
PubMed1992

Tunicate muscle actin genes. Structure and organization as a gene cluster.

We have isolated and determined the complete nucleotide sequences of two genes, HrMA4a and HrMA2, which encode the same muscle actin protein of the tunicate Halocynthia roretzi. HrMA4a and HrMA2 contain three exons, and the genes have intron-exon splice junctions at the same positions. The 5' flanking region of HrMA4a gene contains several potential regulatory elements. A TATA box is located at -30 and a CArG box found in regulatory region of vertebrate muscle-specific genes is located at -116. Seven E-box consensus sequences (CANNTG) known as binding sites for vertebrate myogenic determination factors are found within a 500 base-pair portion of the 5' flanking region of HrMA4a gene. HrMA4a and HrMA2 are separated by 1600 bases in genomic DNA and transcribed in the same direction. In addition to these genes, we have identified three other actin genes encoding muscle-type actins. All five actin genes are located in a 30 x 10(3) base-pair region of the genome and aligned in the same direction. This is the first report of a cluster of "vertebrate-type" muscle actin genes. The consensus sequences of 5' flanking region are conserved among these five genes, suggesting that the expression of the genes is controlled coordinately. This may be advantageous for the accumulation of considerable amounts of actin proteins in rapidly developing embryos of this animal.

Actins↗