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Biomedical subjects

M Nonaka

Publications and source records attributed to M Nonaka.

At least 181 records · Page 10Linked to original sources

P element-induced mutations in Drosophila melanogaster showing high interspecific crossability between D. melanogaster females and D. simulans males.

Homozygous stocks for the second or the third chromosome of Drosophila melanogaster with a single insertional plwB element were screened for high crossability with D. simulans. Reciprocal crosses between each of these stocks and D. simulans were made, and the insemination rate at two or three days was examined. From two cycles of screening of the original 575 stocks, one stock (# 687) which showed high insemination rate was selected and was backcrossed to a w strain to substitute the background. We obtained a stock which showed 10% insemination rate with D. simulans males (control was 0%). No stocks exhibiting a high crossability with D. simulans females were acquired. Revertant strains, from which the P element had been lost, were obtained from the backcrossed # 687 stock. The insemination rates of 13 revertants to D. simulans males ranged from 1% to 33%. Seven of these 13 were not significantly different from the control line but were significantly different from the backcrossed # 687 stock. It was concluded that the mutation showing high crossability with D. simulans males was caused by the P element transposition.

Animals↗

Epistatic interactions among the P element-induced high interspecific crossability strains in Drosophila melanogaster.

Five Drosophila melanogaster strains showing high interspecific crossability with D. simulans males, derived from the previous screening of a set of autosomal plwB transposants, were selected and the effect of the plwB insertion under the same genetic background (white strain) on the interspecific crossability was examined. This phenotype was recessive in the two strains but semidominant in the other three strains. Trans-heterozygotes, however, showed high interspecific crossability compared with the parental homozygotes, suggesting some epistatic interactions between them. In three strains, the effect of the plwB insertion region in different backgrounds (w1118 strain) on the crossability was also tested. Homozygotes of a strain (#687) showed high interspecific crossability comparable to the w background, while homozygotes of both #68 and #783 strains showed lower crossability than w1118. Although #783 heterozygotes showed intermediate values between #783 homozygotes and w1118, #68 heterozygotes showed a significantly higher insemination rate than w1118 and the #68 homozygotes. These results suggest that the region around the plwB insertion sites of #68 and #783 affects the interspecific crossability either positively or negatively depending on the genetic background. In all the stocks, positive correlation between interspecific crossability and the intraspecific mating speed was detected.

Animals↗

Effects of sesamin and alpha-tocopherol, individually or in combination, on the polyunsaturated fatty acid metabolism, chemical mediator production, and immunoglobulin levels in Sprague-Dawley rats.

Feeding sesamin and alpha-tocopherol in combination, both at the 0.5% dietary level, to Sprague-Dawley rats for 3 weeks resulted in a trend toward decreasing the proportion of 20:4n-6 and 22:5n-6 and increasing that of 18:2n-6 in phosphatidylcholine from various tissues, suggesting interference with the metabolism of linoleic acid. This dietary manipulation significantly reduced the production of leukotriene C4 in the lung, the splenic production of leukotriene B4, and reduction of the plasma histamine level. Simultaneous administration of sesamin and alpha-tocopherol significantly increased the production of IgA, IgG, and IgM by mesenteric lymph node lymphocytes, while the IgE level tended to be reduced. These effects were not necessarily apparent by feeding these compounds separately. Thus, sesamin and alpha-tocopherol in combination would be effective for regulating the eicosanoid production and modifying the immune function.

Animals↗

[A case of extirpation of the extrapleural plombs].

A 75-year-old male, who had undergone left extrapleural plombage for left pulmonary tuberculosis 46 years before, was admitted because of cough and sputum. The Chest X-ray and CT-scan films on admission show fluid collection in plombs. Left postero-lateral thoractomy was performed on January 14, 1994. There were thickness of the parietal pleura and no findings of empyema or fistulas. Extrapleural plombs and partial part of the vegetation were removed safely. There were two damaged plombs and fluid collection in another two plombs. No findings of residual tuberculosis were found on postoperative pathological and bacteriological examinations. He has been well for 8 months postoperatively.

Aged↗

[Surgical problem of lung cancer with coexisting acute pulmonary tuberculosis].

Four patients with coexistent lung cancer and acute pulmonary tuberculosis were operated during recent 5 years. All were males and cigarette smokers (B.I. > 600). Adenocarcinoma were recovered from 3 patients, while the remaining 1 had squamous cell carcinoma. Only 1 curative resection was performed for lung cancer. In most cases, late stage of the disease was alleged to be a factor contributing to the poor prognosis.

Acute Disease↗

Isolation of the Xenopus complement factor B complementary DNA and linkage of the gene to the frog MHC.

C factor B (Bf) is the key component of the C3 convertase of the alternative C pathway, and its gene resides in the class III region of the mammalian MHC. To elucidate the evolution of both the C system and the MHC, we isolated Bf cDNA clones from Xenopus laevis, an ectothermic vertebrate in which the MHC has been well defined at both the biochemical and functional levels. A part of the serine protease domain of the Xenopus Bf mRNA was amplified by reverse transcriptase-PCR, using degenerate primers corresponding to regions encoding the perfectly conserved amino acid sequences found in both the mouse Bf and C2 proteins. A full length Xenopus Bf cDNA clone was isolated from a Xenopus liver cDNA library. The deduced amino acid sequence of 747 residues showed the same domain structure as mammalian Bf and C2: three short consensus repeat domains, a von Willebrand domain and a serine protease domain. Xenopus Bf has 40% and 30% overall amino acid identity to mouse Bf and mouse C2, respectively. Because the amino acid identity between mouse Bf and mouse C2 is 38%, the gene duplication of Bf/C2 probably occurred before the divergence of amphibians and mammals. Southern blotting analysis of the Xenopus Bf gene showed a close linkage to the MHC, indicating that the Bf gene was linked to the class I and class II genes at the time Xenopus shared a common ancestor with mouse and man, 350 x 10(6) yr ago.

Amino Acid Sequence↗

Molecular cloning of a lamprey homologue of the mammalian MHC class III gene, complement factor B.

To elucidate the origin and evolution of the complement system and the MHC, we isolated cDNA clones for the MHC class III complement factor B (Bf) gene from lamprey, one of the most primitive extant vertebrates. A part of the serine protease domain of the lamprey Bf was amplified by reverse transcriptase-PCR using the degenerated primers corresponding to the conserved amino acid stretches between the mouse Bf and C2 sequences. A full-length lamprey Bf cDNA clone was isolated from the lamprey liver cDNA library using a PCR-amplified DNA clone as a probe. The deduced amino acid sequence of 763 residues showed essentially the same domain structure as mammalian Bf or C2, consisting of three short consensus repeat domains, a von Willebrand domain, and a serine protease domain. Lamprey Bf showed 33 and 29% overall amino acid similarity to mouse Bf and mouse C2, respectively, whereas amino acid similarity between mouse Bf and mouse C2 was 36%, suggesting that the gene duplication of Bf/C2 occurred in the main line of vertebrate evolution after the divergence of cyclostomes. This is the first report of the molecular cloning from cyclostomes of a component of the mammalian MHC that offers the possibility of genetic analysis of the presumably primitive MHC of cyclostomes.

Amino Acid Sequence↗

Molecular cloning of the rat complement regulatory protein, 5I2 antigen.

We have cloned a cDNA which encoded for rat complement regulatory protein, 5I2 antigen. The deduced amino acid sequence of 497 residues predicted essentially the same domain structure as the mouse complement regulatory protein, Crry/p65, composed of five short consensus repeat (SCR) domains, a transmembrane domain and a cytoplasmic domain. 5I2 antigen, however, had an additional SCR which showed a close similarity to the sixth SCR of mouse complement receptor 1 (CR1) or to the sixth, thirteenth, twentieth and twenty seventh SCR of human CR1. Corresponding domains of 5I2 antigen and mouse Crry/p65 showed 70%-86% amino acid identity, indicating that 5I2 antigen is the rat counterpart of mouse Crry/p65.

Amino Acid Sequence↗

Immunological approach to Ménière's disease: vestibular immune injury following immune reaction of the endolymphatic sac.

Following direct antigen challenge to the endolymphatic sac (sac), the relation of caloric test results and spontaneous nystagmus to the histological changes of the sensory epithelium of the vestibular organ and perilymph antibody levels was investigated in the guinea pig. In a secondary keyhole limpet hemocyanin (KLH) challenge to the sac, irritative nystagmus was followed by paralytic nystagmus and a suppression of caloric reaction. These findings correlated well with the degree of degeneration of the sensory epithelium of the vestibular organ and the levels of perilymph antibody. On the other hand, neither phosphate-buffered saline inoculation nor primary KLH challenge to the sac nor a secondary KLH challenge to the intradural space resulted in a disturbance of the vestibular function. These results suggest that the immune response of the sac may possibly be an important key to the pathogenesis of Ménière's disease.

Animals↗

Effect of dietary fats on cholesterol metabolism and eicosanoid production in hamsters fed undigested fraction of soybean protein.

The undigested fraction of soybean protein (UDF) exerts a markedly greater hypocholesterolemic effect than soybean protein itself in rats. The present study was undertaken to confirm the effect in hamsters, a more appropriate animal model for human cholesterol metabolism. Hamsters were given diets containing UDF at a nitrogen level equivalent to the 20% casein diet. Dietary fats, at the 10% level, were perilla oil and safflower oil. There was apparently no increase in the serum and liver cholesterol levels in both groups of animals cholesterol-enriched diets that had been fed for 38 days. Fecal excretion of neutral and acidic steroid tended to be higher in the perilla oil group than in the safflower oil group. The perilla oil group significantly increased 20:5n-3 in liver phosphatidylcholine and phosphatidylethanolamine accompanying a decrease in 20: 4n-6. Such changes were not so evident in liver phosphatidylinositol. The production of leukotriene B4 and the concentration of prostaglandin E2 in the spleen were higher in the safflower oil group than in the perilla oil group. Thus, the hypocholesterolemic effect of the undigested fraction of soybean protein was apparently reproduced even in hamsters. Dietary fat-induced changes in lipid parameters in hamsters resembled those observed in rats.

Animals↗

[Asymptomatic bilateral spontaneous pneumothorax].

Two surgical cases of bilateral pneumothorax founded at a medical examination were reported. Case 1; A 15-year-old male was admitted to our hospital pointed out left spontaneous pneumothorax without complaints. The interval between the first and the contralateral pneumothorax was 3 weeks. He was treated with a one-stage operation through a bilateral axillary incision. Case 2; A 19-year-old male was admitted to our hospital pointed out left spontaneous pneumothorax without complaints. Surgical operation was performed with a left axillary incision. One year after the treatment, he was pointed out right spontaneous pneumothorax on his chest X-ray film. Partial resection of the right lung was performed with a right axillary incision. Of the 261 pneumothorax patients, 28 had bilateral pneumothorax in our hospital. The majority of these patients had complaints which were chest pain, dyspnea and cough. Of the 28 patients, 2 had no complaints at the time of admission. We conclude that we have to follow up carefully the patients with hemilateral spontaneous pneumothorax.

Adolescent↗

[A case of mediastinal malignant lymphoma; 16 years follow up after surgery].

A 32-year-old female was admitted to our hospital on September 1976 because of left mediastinal mass shadows on chest roentgenogram. Needle biopsy studies provided no definitive diagnosis, and exploratory operation was carried out through left postero-lateral thoracotomy. Two large masses were seen in the mediastinum and five small tumors were seen on the diaphragm. All of these masses were removed. Histopathological examination of the tumors indicated non-Hodgkin's lymphoma, diffuse small cell type. Radiation therapy was carried out postoperatively, but chemotherapy could not continue because of side effect. Eight years after surgical therapy, recurrence was seen at left parietal pleura, ten years at peritoneum, twelve years at left parietal pleura, thirteen years at upper mediastinal lymph node, 16 years at post-peritoneal space. These tumors disappeared after radiation therapy. She is doing well seventeen years after the surgery.

Adult↗

Molecular cloning of the b subunit of mouse coagulation factor XIII and assignment of the gene to chromosome 1: close evolutionary relationship to complement factor H.

The b subunit of human coagulation factor XIII (FXIII-b) is composed of 10 short consensus repeats (SCRs) characteristic of the regulatory proteins of complement activation system. A full-length cDNA clone of mouse FXIII-b was isolated and the entire sequence was determined. The predicted amino acid sequence showed 77.5% homology with human FXIII-b, although mouse FXIII-b contained seven extra amino acid residues at the carboxyl terminal. The strong reactivity of the translation product of this clone with rabbit anti-human FXIII-b antiserum confirmed that it encodes a mouse counterpart of the human FXIII-b. By in situ hybridization and mapping studies using 66 interspecific backcross mice, the mouse FXIII-b gene (designated F13b) was shown to be located on distal chromosome 1 closely linked to Cfh, extending a conserved linkage group between human and mouse chromosome 1. In addition, a significant structural similarity between FXIII-b and complement factor H is described.

Amino Acid Sequence↗

Purification and characterization of interferon-like antiviral protein derived from flatfish (Paralichthys olivaceus) lymphocytes immortalized by oncogenes.

Flatfish leukocytes were transfected with the expression plasmids of the v-myc, c-myc, c-fos, v-myb and c-Ha-ras oncogenes. Only cotransfection of c-Ha-ras with c-myc or c-fos resulted in complete immortalization of the cells. Interferon-like anti-viral protein was found in the cultured medium of the immortalized lymphocytes. The protein was purified by DEAE-Toyopearl 650 M ion exchange chromatography and WGA agarose affinity chromatography. The protein was a glycoprotein of about 16 kDa. The antiviral activity of the protein was trypsin-sensitive and was fairly stable at pH values from 4 to 8. The protein retained about 60% of the activity even at 60 degrees C and showed a broad antiviral activity for various fish cells and viruses.

Animals↗