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Biomedical subjects

M Nonaka

Publications and source records attributed to M Nonaka.

At least 19 recordsLinked to original sources
PubMed1992

Insertion of the B2 sequence into intron 13 is the only defect of the H-2k C4 gene which causes low C4 production.

The serum level of the fourth component of complement (C4) in mice bearing H-2k haplotype is only 1/10 of that of non-H-2k mice. H-2k bearing mice, but not non-H-2k bearing mice, have an insertion of the B2 sequence into intron 13 of the C4 gene, and aberrant C4 mRNA in liver apparently generated by abnormal RNA splicing caused by the insertion of the B2 sequence. To test the possible causal relationship between the B2 insertion and low C4 production in H-2k mice directly, we constructed the H-2k C4 gene without the B2 insertion and the H-2w7 (non-H-2k) C4 gene with the B2 insertion by exchanging a part of intron 13 between these two genes. Transfection of the intact H-2w7 C4 gene or the chimeric H-2k gene without the B2 insertion into HepG2 cells resulted in the production of only normal C4 mRNA at the normal level. On the other hand, the intact H-2k C4 gene or the chimeric H-2w7 C4 gene with the B2 insertion directed production of both aberrant and a decreased amount of normal C4 mRNA. These results demonstrated that the insertion of B2 sequence into intron 13 of the C4 gene is the only determinant of low C4 production by H-2k mice through aberrant RNA processing.

Animals↗
PubMed1992

Complete complementary DNA sequence of the third component of complement of lamprey. Implication for the evolution of thioester containing proteins.

Lamprey liver mRNA sequences were amplified by reverse transcriptase-polymerase chain reaction using primers synthesized according to the amino acid sequences at the thioester region common to the mammalian C3, C4, and alpha 2-macroglobulin (alpha 2M). Two different cDNA species were identified that showed a close similarity to the mammalian C3 or alpha 2M sequences, respectively. Using the C3-like sequence as a probe, two overlapping cDNA clones were isolated from the lambda ZAP library, which together covered the entire region encoding the putative lamprey pro-C3. The deduced amino acid sequence of the putative lamprey pro-C3 contained 1660 amino acids and showed 31%, 22%, 23%, and 16% amino acid sequence identity with mouse C3, C4, C5, and human alpha 2M, respectively. The distributions of cysteine residues were completely identical between the mouse C3 and the putative lamprey C3 except that the lamprey sequence had two additional cysteine residues in the alpha-chain. The possible beta-alpha and alpha-gamma processing sites were found at exactly the same positions as in mammalian C4. These results suggest that the putative lamprey C3 retains a close similarity to the common ancestor of the mammalian C3 and C4, which appeared to have had a three-subunit chain structure.

Amino Acid Sequence↗
PubMed1992

Aberrant splicing caused by the insertion of the B2 sequence into an intron of the complement C4 gene is the basis for low C4 production in H-2k mice.

The serum level of the fourth component of complement (C4) in mice bearing the H-2k haplotype is only 1/10 to 1/20 of that of non-H-2k mice. We have analyzed C4 cDNA clones from B10.BR(H-2k) mouse liver and found aberrant C4 cDNA which contained a 200-base pair (bp) insertion between the exon 13 and exon 14 encoded sequences in addition to the normal C4 cDNA. The 5' 148 bp and the 3' 52 bp of this insert were derived from the B2 sequence, the short interspersed repeats of mouse genome, and the central part of intron 13, respectively. Sequence analysis of intron 13 of the C4k gene showed the presence of a complete copy of a B2 consensus sequence. The structure of aberrant C4 mRNA indicated that the possible 3' splice site in the B2 sequence and the cryptic 5' splice site in intron 13 were used. Both the insertion of the B2 sequence into intron 13 and the presence of aberrant mRNA in the liver were specific to H-2k-bearing mice, suggesting that the aberrant splicing due to the B2 insertion is the basis for low C4 expression in H-2k mice.

Animals↗
PubMed1992

Covalent binding of C3b to C4b within the classical complement pathway C5 convertase. Determination of amino acid residues involved in ester linkage formation.

C5 convertase of the classical complement pathway is a protein complex consisting of C4b, C2a, and C3b. Within this complex C3b binds to C4b via an ester linkage. We now present evidence that the covalent C3b-binding site on human C4b is Ser at position 1217 of C4. We also show that formation of the covalently linked C4b.C3b complex occurs in the mouse complement system and that the C3b-binding site on mouse C4b is Ser at position 1213 which is homologous to Ser-1217 of human C4. Therefore, covalent binding of C3b to a single specific site on C4b within the classical pathway C5 convertase is likely a common phenomenon in the mammalian complement system. Specific noncovalent association of metastable C3b with C4b would occur first, leading to reaction of the thioester with a specific hydroxy group. This is supported by two lines of experimental evidence, one which shows that a mutant C4 that does not make a covalent linkage with C3b is still capable of forming C5 convertase and a second in which the C4b.C3b complex has been demonstrated by cross-linking erythrocytes bearing this C5 convertase.

Amino Acid Sequence↗
PubMed1992

Molecular cloning of mouse beta 2-glycoprotein I and mapping of the gene to chromosome 11.

beta 2-Glycoprotein I (beta 2 GPI), a plasma protein that binds to anionic phospholipids, is composed of five repeating units called a short consensus repeat (SCR), which is found mostly in the regulatory proteins of the complement system. Recently the human beta 2 GPI gene has been assigned to chromosome 17, not to chromosome 1 where most of the genes of the SCR-containing proteins are clustered. In this report, we have isolated a full-length cDNA clone of mouse beta 2 GPI and determined the chromosomal localization of the gene. The amino acid sequence deduced from the nucleotide sequence of mouse beta 2 GPI revealed 76.1% identity with that of human beta 2 GPI. A genetic mapping by in situ hybridization and linkage analysis using 50 backcross mice has shown that the mouse beta 2 GPI gene (designated B2gp1) is located on the terminal portion of the D region of chromosome 11, closely linked to Gfap, and is 18 cM distal to Acrb, extending a conserved linkage group between mouse chromosome 11 and human chromosome 17. On the basis of these results, the evolutionary relationships among the SCR-containing proteins are discussed.

Amino Acid Sequence↗
PubMed1992

Vestibular disorders following immune response of the endolymphatic sac in the guinea pig.

The effect of a direct antigen challenge to the endolymphatic sac on vestibular function was investigated in guinea pigs. Following keyhole limpet hemocyanin (KLH) challenge to the sac in systemically presensitized guinea pigs, caloric responses were examined in 18 animals on days 1, 7, 14, 21, and 28. Caloric responses were significantly suppressed in 13 animals by day 7; of these, 5 animals had recovered by day 14 and 8 animals had not yet recovered by day 28. The behavior of spontaneous nystagmus was examined every hour in 10 animals at intervals of 3 to 56 hours after sac challenge. Irritative spontaneous nystagmus preceding paralytic nystagmus appeared in 5 animals, for which the mean onset was 14.6 +/- 3.1 hours and the mean duration was 4.4 +/- 6.5 hours. Paralytic spontaneous nystagmus appeared in all animals, for which the mean onset time was 23.3 +/- 12.3 hours. Neither direct KLH primary challenge of the sac nor phosphate-buffered saline injection to the sac caused significant changes in the vestibular function. These results suggest that an immune response of the sac induces a vestibular disorder and may produce an attack of vertigo similar to that of Meniere's disease.

Aged↗
PubMed1992

[Two cases of broncholithiasis removed by bronchofiberscopy].

Two cases of broncholithiasis, removed bronchoscopically, are reported. Case 1 was a 38-year-old female who was admitted with hemoptysis. The chest tomogram showed calcification near the right middle lobe bronchus. Bronchoscopy revealed a broncholith in B4. Component analysis showed that more than 98% of this stone consisted of calcium carbonate. Case 2 was a 75-year-old male who was hospitalized because of continuous cough. The chest radiograph showed calcification and atelectasis in the right upper lobe. Bronchoscopically, right B3 was obstructed by a broncholith. After removal of the stone, the distal part of B3 was noted to be filled with pus. Analysis of the stone's composition revealed calcium phosphate (77%) and calcium carbonate (23%).

Adult↗
PubMed1992

[Lobular carcinoma of the male breast--a case report].

Lobular carcinoma of the male breast is very rare, because lobules do not exist in the male mammary gland. Seven cases of lobular carcinoma of the male breast have been reported in Europe and U.S.A., although no case in Japan. We encountered a very rare case of the lobular carcinoma of 74-year-old male breast. Histopathological examinations of both primary tumor and recurrent tumors of the skin led to the diagnosis of lobular carcinoma.

Aged↗
PubMed1991

Differential expression of the five C4-related genes of H-2w7 mice.

Mice bearing the H-2w7 haplotype have five C4-related genes, one C4, one Slp, and three C4/Slp hybrid genes. The expression of these five genes in the liver of H-2w7 mice was estimated at the steady state level of their respective mRNA. We have amplified by the polymerase chain reaction (PCR) three regions of the C4/Slp mRNA where some of these five genes show nucleotide substitution. A relative amount of each gene product was estimated by single-strand conformation polymorphism (SSCP) analysis or by direct counting of the number of respective clones after subcloning into a plasmid vector. A steady state level of the C4 mRNA was most abundant among C4-related gene transcripts. The hybrid 1 and 3 genes were expressed at a similar level which is about 1/2-1/3 of the C4 level. The hybrid 2 gene was expressed at about 1/5 of the hybrid 1 or 3 level. Neither male nor female H-2w7 mice expressed the Slp gene. These results showed that the expression of the five C4-related genes of H-2w7 mice is differentially regulated in spite of the close similarity in the nucleotide sequences in both the 5' flanking and coding regions of these genes.

Animals↗
PubMed1991

A new method of hernioplasty for adult groin hernias centering on repair of the transversalis fascia.

A new method of hernioplasty for adult groin hernias centering on repair of the transversalis fascia was assessed by a questionnaire conducted every five years on adult patients who had received the above operation. The efficacy of this method was evaluated in terms of the postoperative quality of life and prevention of recurrence of groin hernias. Over the last 9 years, 834 adult patients with 921 groin hernias, including bilateral lesions, have undergone the above procedure and overall, favorable results were obtained, with only one case of recurrence (0.1 per cent) being reported. Contralateral herniation, which has been often reported following Bassini's or Hatakoshi's method, was found in only one of our patients although the number of patients who complained of pain in the operated region was comparatively high, being 51 cases or 11.4 per cent.

Adult↗
PubMed1991

Microbial sensor system for nondestructive evaluation of fish meat quality.

A microbial sensor system consisting of the bacterium (Alteromonas putrefaciens) immobilized within membranes, a flow cell, an oxygen electrode, peristaltic pumps, a buffer tank, a thermostatically controlled bath and a recorder, was constructed for the nondestructive quality evaluation of bluefin tuna. The chemical compounds on fish meat surfaces which are the indicators of fish meat quality were rapidly determined by using the proposed sensor system. Fish meat quality was determined from the rate of current decrease of the sensor. Good correlations were obtained between fish meat quality and sensor response. One assay could be completed within one minute.

Animals↗
PubMed1991

Human rib bone marrow mononuclear cells spontaneously synthesize and secrete IgE in vitro.

We have examined spontaneous secretion of IgE by human rib bone marrow mononuclear cells (MNC). Bone marrow MNC from nine out of 12 rib specimens synthesized and secreted substantial amounts of IgE during 14 days of in vitro culture. The 14-day supernatants from these bone marrow MNC contained a mean of 2589 pg/ml of IgE (n = 12) with a maximum production of 15,408 pg/ml of IgE compared with small amounts of IgE (80-200 pg/ml) produced by similarly cultured normal and inflammatory bowel disease intestinal lamina propria MNC. Using two rib specimens, time-course studies revealed spontaneous secretion of IgE to be minimal during the first 2 days of culture (152 pg/ml), followed by a steady increase between days 4 (517 pg/ml) and 14 (3588 pg/ml). The addition of pokeweed mitogen resulted in 72% suppression of spontaneous IgE production by bone marrow MNC. The bone marrow MNC isolated from the ribs consisted of 22% Leu12+ (B) cells of which 3.2% were surface IgE positive. Staining for cytoplasmic immunoglobulin revealed 1% of the bone marrow MNC to be cytoplasmic IgE+. The presence of IgE-bearing and IgE-secreting MNC in human bone marrow is consistent with the observation that allergen-specific IgE-mediated hypersensitivity is adoptively transferred by human bone marrow transplantation and demonstrates the usefulness of human bone marrow MNC for examination of IgE secretory and regulatory events.

Adult↗
PubMed1991

[Effect of inner ear immune response on vestibular function in guinea pigs].

We examined vestibular dysfunction and histological damage caused by direct antigen challenge to the endolymphatic sac in guinea pigs. We observed spontaneous nystagmus every eight hours and performed caloric testing every week following endolymphatic sac secondary KLH challenge. Spontaneous nystagmus was seen in 12 of 18 animals, and nystagmus in all directed toward the unchallenged ear (paralytic). The caloric response time courses were classified into two types, which were irreversible type and reversible type after endolymphatic sac KLH challenge. The immune injury of animals with irreversible type was thought to be stronger than that of these with reversible type. The spontaneous nystagmus of irreversible type animals was longer than that of reversible type animals. The temporary vestibular dysfunction was thought to be similar to that observed in Meniere's disease.

Animals↗
PubMed1991

[Development of acute endolymphatic hydrops following secondary endolymphatic sac immune response. I: Short-term observation].

The development of endolymphatic hydrops (e. hydrops) following secondary e. sac immune response was investigated in Hartley guinea pigs, for a period of 5 weeks. E. hydrops immediately developed to a maximum from day 2 to day 7 and then gradually reduced in the next 4 weeks. In the e. sac, numerous inflammatory cellular infiltrates, mainly polymorphonuclear cells and macrophages, were seen from day 1 to day 2. Lymphocytes and plasma cells appeared from day 3 and increased to a maximum by day 7 and then gradually decreased in the next 4 weeks. Neither primary e. sac KLH challenge nor e. sac PBS inoculation could derive e. hydrops. Development of e. hydrops was considerably parallel to the grade of immune reaction within the e. sac, suggesting that immuno-pathological reaction of the e. sac has an important effect on regulation of the endolymph volume.

Acute Disease↗
PubMed1991

[A case report of cavernostomy for lung aspergilloma].

A 65-year-old male patient with right upper lobe aspergilloma treated surgically due to continuation of hemoptysis was reported. Cavernostomy was indicated in this patient, since he had a low respiratory function. After cavernostomy, cavitry infection with MRSA occurred and additional operation was necessary. We should gave great care to intra-cavitary infection. Loss of lung function after the operation seemed to be minimal.

Aged↗