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Biomedical subjects

S Maeda

Publications and source records attributed to S Maeda.

At least 739 records · Page 41Linked to original sources
PubMed1989

[Clinical application of extracorporeal microexplosive lithotripsy].

A total of 46 cases underwent 66 treatments with extracorporeal microexplosive lithotripsy (EML) for upper urinary tract calculi between March 10, 1987 and May 28, 1987. The efficacy of EML therapy was investigated in all cases over 3 months. The lithotripter of EML made by the Yachiyoda Co. Ltd (SZ-1) was adapted to a microexplosion (10 mg silver azide) as the source of energy for underwater shock wave generation. Fifteen cases (32.6%) had a history of previous open lithotomy of the same upper urinary tract as being treated by EML. Pre-treatments with ureteral catheters and ureteral stents were performed in 4 and 4 cases (8.7% and 8.7%), respectively. The microexplosions were conducted in syncronization with patient exhalation from 100 to 400 times during 1 session, depending upon the size of the stone. The patients felt pressure only on their back at the pulse of explosion and complained occasionally a dull pain, but this pain was mild and tolerable, and no patients required anesthesia. When stone disintegration was judged to be unsatisfactory, that is the stone remained unfragment or the size of the residual stone fragments was greater than 5 mm., an additional session was performed, usually 1 week after the previous session. On the X-ray film obtained three months after EML treatment, 26 cases (57%) were completely free from stone concerments, 17 cases (37%) had stone fragments of equal to or less than 5 mm and 3 cases (6%) had ones of greater than 5 mm. Treatment of EML alone was performed in 44 cases (96%), while 2 cases (4%) required transurethral stone manipulation following EML.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

Ribosomal RNA gene (rDNA) distribution in human leukemia cells by in situ hybridization on chromosome.

By in situ hybridization on chromosome, phytohemagglutinin (PHA)-stimulated lymphocytes obtained from normal individuals showed slight polymorphism in terms of distribution of rDNA among Nucleolar Organizer Region (NOR) chromosomes probably due to racial differences, although their interindividual distinct polymorphism had been reported in the U.S.A. Three chronic and one acute myelogenous leukemias (CML and AML) and one chronic monocytic leukemia (CMoL) were also analysed for the distribution of rDNA among NORs. The distribution patterns in leukemia cells were found to be significantly different from those in the cells of normal individuals. Although genetic alteration of normal leukocytes was not disregarded, the changes of rDNA distribution in leukemia cells are demonstrated in this study. The Ph1 chromosome in CML carried a greater amount of rDNA. The rDNA distribution in Ph1-negative cells obtained from patients showed almost the same pattern as that of Ph1-positive cells. In AML, the t(8;21) carried a smaller amount of rDNA. Trisomic chromosome 21 in CMoL carried extra rDNA copies on its NOR. Based on these data, leukemia cells seem to show variability of rDNA distribution especially on marker chromosomes, contrary to the non-polymorphic patterns of normal lymphocytes. Thus a strong relationship between marker formation and abnormal distribution of rDNA could be suggested.

Chromosomes, Human↗
PubMed1989

Solitary retroperitoneal neurofibroma: a case report.

A solitary neurofibroma arising in the retroperitoneal space without any other stagma of von Recklinghausen's disease is reported. Confusion with another nerve sheath tumor, a schwannoma is a diagnostic pitfall. Histochemical and immunohistochemical stainings of the tumor are useful for the diagnosis of solitary neurofibroma.

Female↗
PubMed1989

[Surgical treatment of thoracoabdominal aortic aneurysm: detection and prevention of spinal cord injury].

Five cases with thoracoabdominal aneurysm underwent surgical treatment under the monitoring of somatosensory evoked potentials (SEP) and spinal cord perfusion pressure [SCPP, the pressure difference between mean distal aortic pressure (MDAP) and cerebrospinal fluid pressure CSFP)]. The reconstruction of major branches of abdominal aorta and intercostal arteries were also performed. The surgical results and data of SEP, CSFP and SCPP during the cross-clamping were reported. Our procedures to detect and prevent ischemic spinal cord injury based on the experiments performed in our department were also summarized as follows: (1) Segmental cross-clamping should be applied during the reconstruction of thoracoabdominal aorta. (2) Major intercostal or lumbar arteries should be reconstructed. (3) SEP should be monitored to detect the spinal cord ischemia. (4) SCPP should be maintained at more than 40 mmHg by increasing MDAP and/or decreasing CSFP.

Adult↗
PubMed1988

Structure of the mouse C-reactive protein gene.

A genomic DNA clone corresponding to the mouse C-reactive protein (CRP) has been isolated and characterized. The mouse CRP gene is 1.9-kilobase pairs in length and contains a single intron of 213-base pairs which interrupts the codon for the 2nd amino acid residue of the mature CRP protein. We compared nucleotide sequences of the mouse and human CRP genes and discussed structures of possible regulatory sequences. With this characterization, the isolation and sequence analyses of a set of mouse and human pentraxin genes, i.e. CRP and serum amyloid P component genes is not complete.

Amino Acid Sequence↗
PubMed1988

Activation of the ompC gene by the OmpR protein in Escherichia coli. The cis-acting upstream sequence can function in both orientations with respect to the canonical promoter.

Expression of the ompC gene coding for an outer membrane protein of Escherichia coli is regulated by a transcriptional activation mechanism that requires the ompR gene product that acts on nucleotide sequences located upstream of the -35 and -10 regions of the ompC promoter. Using an ompC-lacZ fusion gene, the orientation of the cis-acting upstream sequence (OmpR-binding site) with respect to the canonical -35 and -10 regions (RNA polymerase-binding site) was changed. The ompC gene was activated in an OmpR-dependent manner even when the upstream sequence was in the reverse orientation with respect to the -35 and -10 regions, providing that these two DNA elements were aligned stereospecifically on the DNA helix. Evidence is presented that the upstream sequence can increase the transcription efficiency of the ompC promoter in a manner relatively independent of its orientation with respect to the -35 and -10 regions.

Bacterial Outer Membrane Proteins↗
PubMed1988

Enzyme-linked immunosorbent assay of lipoprotein(a) in serum and cord blood.

We have developed a new sensitive method for quantifying lipoprotein(a) (Lp(a] in human serum, using a 'sandwich' type noncompetitive enzyme-linked immunosorbent assay (ELISA). The solid-phase used was a polystyrene plate. The anti-Lp(a) antibody-enzyme conjugate was labelled by linking Fab' fragments to peroxidase (EC 1.11.1.7) by the maleimide method. The minimum detectable concentration was 0.5 ng/well. Routinely, the assay was carried out with 1,000-fold diluted serum, and Lp(a) was quantified between 4.0 and 500 mg/l. Within-run coefficients of variation (CVs) ranged from 3.5% to 10.4% and between-run CVs from 5.0% to 11.1%. Results by the ELISA were in good agreement with those by radial immunodiffusion (r = 0.955). The distribution of Lp(a) in serum from 820 healthy donors was highly skewed: mean 141.1 mg/l, medium 97.9 mg/l. In cord blood, the mean and median were 15.6 and 9.8 mg/l, respectively. This ELISA for Lp(a) has the advantages of being highly sensitive and specific, simple to perform, and does not use radioisotopes.

Adolescent↗
PubMed1988

Structure of the mouse serum amyloid P component gene.

A genomic DNA clone corresponding to the mouse serum amyloid P component (SAP) has been isolated and characterized for the first time. The numbers of exons, the relative sites of intron/exon junctions, and the size of the coding region for mature SAP protein are all in complete agreement with those of the human SAP gene. In the 5'-flanking region of the mouse SAP gene, there is a small DNA segment (43-base pairs) which is highly homologous with the corresponding region of the human SAP gene. However, most parts of the 5'-flanking regions are not conserved between the mouse and human SAP genes, and several phorbol ester-responsive element-like sequences are present only in the mouse SAP gene.

Amino Acid Sequence↗
PubMed1988

Acute-phase response of mRNAs for serum amyloid P component, C-reactive protein and prealbumin (transthyretin) in mouse liver.

Acute-phase response of mRNAs for serum amyloid P component (SAP), C-reactive protein (CRP) and prealbumin was examined in C57BL/6 mouse liver by hybridization to specific cDNA probes. Although the level of SAP mRNAs in the unstimulated mouse was about one-tenth of that of CRP mRNAs, it increased up to 60-fold during the first 20 hr, and returned gradually to the original level at 69 hr after the administration of Escherichia coli lipopolysaccharide. On the other hand, the level of CRP mRNA rapidly increased up to 6-fold during the first 4 hr, and reverted to the original level as early as at 20 hr. In contrast, the level of mRNA for prealbumin decreased to about 0.5-fold during the first 20 hr, recovered and increased up to 1.6-fold of the original level during 32 to 69 hr.

Animals↗
PubMed1988

Detection of hypermethylation of the c-abl genomic locus in the spleen of juvenile LE rats.

Tumor induction by treatment with polycylic hydrocarbons depends on age and the strains of rats used. Juvenile LE rats are very sensitive to the induction of leukemia and chromosomal breaks by intravenous DMBA injection. We have previously demonstrated a chromosomal translocation in chromosome 3 and 12 in a DMBA induced LE rat leukemia cell K3D. In our present communication we have examined the c-abl expression in the leukemic cell line as well as in the LE rats at different ages. We found that in the leukemic cell K3D the c-abl expression is elevated both at the level of mRNA and protein. In the preleukemic stage, highly elevated expression of c-abl mRNA was detected exclusively in the spleen of the juvenile LE rats. Furthermore this high expression of the c-abl gene correlates well with hypermethylation of possible cytosine residue in the c-abl genomic locus.

Animals↗
PubMed1988

Stereospecific positioning of the cis-acting sequence with respect to the canonical promoter is required for activation of the ompC gene by a positive regulator, OmpR, in Escherichia coli.

Expression of the ompC gene coding for a major outer-membrane protein of Escherichia coli is regulated by a transcriptional activation mechanism that requires the ompR gene product, OmpR. It was demonstrated that multiple OmpR molecules bind to a cis-acting sequence located upstream from the canonical -35 and -10 regions of the ompC promoter. Using an ompC-lacZ fusion gene, the distance between the cis-acting upstream sequence (OmpR-binding site) and the -35 and -10 regions (RNA polymerase-binding site) has been changed. We demonstrated that the ompC transcription was activated in an OmpR-dependent manner even when the cis-acting upstream sequence was separated from the -35 and -10 regions by several turns of the DNA helix, providing that the distance between them was a near-integral multiple of one turn of the DNA helix. Evidence is presented that stereospecific positioning of the cis-acting upstream sequence with respect to the canonical promoter is required for activation of the ompC gene by the positive regulator, OmpR.

Bacterial Outer Membrane Proteins↗
PubMed1988

Expression of human papillomavirus type 6b E2 gene product with DNA-binding activity in insect (Bombyx mori) cells using a baculovirus expression vector.

Human papillomavirus type 6b (HPV6b) has been shown to be a major etiologic agent of genital condylomas. The E2 gene, one of the early genes, has been shown to activate the enhancer element in trans in cells transformed with bovine papillomavirus type 1a (BPV1a) but the E2 gene product of any HPV has not been identified. The E2 gene of HPV6b was inserted into the polyhedrin gene of a Baculovirus, Bombyx mori nuclear polyhedrosis virus (BmNPV), 156 bp downstream from the translational start codon, and transferred into BmNPV by allelic replacement in a cotransfected Bombyx mori cell line, Bm-N. The predicted 46-kDa protein was produced by a recombinant virus in the infected Bm-N cells at a high level under the control of the polyhedrin promoter. We obtained the antibody against the putative E2-polyhedrin fusion protein by immunizing a rabbit with this protein. This protein reacted with the antibodies against polyhedrin and the fusion protein. This protein did specifically bind to the upstream regulatory region of the HPV6b and BPV1a genomes. This DNA binding activity was blocked by the antibody against this protein.

Animals↗
PubMed1988

Cloning and sequence analysis of a cDNA for lymphocyte proliferation potentiating factor of rabbit polymorphonuclear leukocytes: identification rabbit interleukin 1 beta.

Complementary DNA for a rabbit PMN-derived lymphocyte proliferation potentiating factor (PMN factor) was cloned from a cDNA library constructed from poly(A)+RNA of early inflammatory exudate PMN. Oligodeoxyribonucleotides as probes for cloning were synthesized according to the previously reported amino acid sequence of the purified PMN factor. This cDNA encodes a 268-residue protein which is homologous to the established structures of human IL 1 beta (74%0 or murine IL 1 beta (71%). The NH2-terminal amino acid sequence of the endogenously produced PMN factor indicates that the mature molecule is made up of carboxy terminal 152 amino acids of the precursor molecule. Taking into consideration the previous studies on biological activities, this cloned PMN factor is therefore considered to be rabbit IL 1 beta.

Amino Acid Sequence↗
PubMed1988

An autosomal dominant mutation of facial development in a transgenic mouse.

We have created a transgenic mouse which showed an autosomal dominant mutation of facial development. This facial malformation was characterized by a short snout and a twisted upper jaw. All offspring showing the dysmorphic phenotype carried the injected gene. In order to analyze the primary cause of this mutation, newborn mice and embryos were examined. The outcome was that the malformation of nasal and premaxillary bone was not the primary defect but was a secondary event. The primary cause of this dysmorphism was a developmental defect in the first branchial arch. Genomic DNA fragments flanking the insertion site of this mutant mouse were cloned. Using these fragments, we have assigned the integration site to chromosome 13. The gene responsible for a previously reported mutant mouse, one which also has a short snout, is also reported to be on chromosome 13. In the fragments flanking the insertion site of the transgenic mouse, at least one fragment was highly conserved in mammals. These results indicate that this malformation is due to the insertional disruption of a host gene. However, the possibility that this mutation is caused by an inappropriate expression of the injected gene still remains to be investigated.

Animals↗
PubMed1988

Inhibition of cardiac Na+, K+-ATPase activity by dynorphin-A and ethylketocyclazocine.

The effect of various opioids on Na+, K+ -ATPase partially purified from rat heart was examined. Dynorphin-A (1-13), dynorphin-A (1-17) and ethylketocyclazocine (EKC), which are k-type opiate agonists, markedly inhibited the enzyme activity in a dose-dependent manner; IC50 values were 12 microM, 21 microM and 0.38 mM, respectively. Morphine (mu-type agonist), methionine- and leucine-enkephalin (delta-type agonist) at the concentration of 1 mM did not affect the enzyme activity. The effect of dynorphin-A (1-13) and EKC was not antagonized by naloxone. Dynorphin-A (1-13) mainly decreased Vmax value without the change of Km value in the activation of Na+, K+-ATPase by ATP, Na+ and K+. Dynorphin-A(1-13) inhibited the partial reactions of Na+, K+-ATPase at the different degree of the potency; the inhibition of K+-stimulated phosphatase was greater than that of Na+-dependent phosphorylation. The present study suggests that dynorphin-A and EKC have an effect on cardiovascular system which is mediated by the inhibition of Na+, K+-ATPase in the heart.

Adenosine Triphosphate↗
PubMed1988

Induction of chromosomal aberrations in rat bone marrow cells and mutations in Salmonella typhimurium by benz[a]anthracene derivatives.

Benz[a]anthracene (BA) and its derivatives containing methyl and/or ethyl groups in the 7 and/or 12 positions were tested for their ability to induce chromosome aberrations (CA) in rat bone marrow cells and for their mutagenicity to Salmonella typhimurium TA100 or TA98. The incidence of aberrant cells induced by the BA derivatives, given in lipid emulsion as a single-pulse dose of 50 mg/kg body weight into the caudal vein, was in the order: DMBA greater than EMBA greater than MEBA greater than other BA derivatives = control. The alkyl groups, at least 1 methyl group, at the 7 and 12 positions of BA seemed to be necessary to induce CA, although DEBA having ethyl groups at both the 7 and 12 positions of BA did not induce CA. DMBA or EMBA induced not only gaps and breaks but also exchanges and multiple CA, while the CA induced by other BA derivatives consisted of only gaps and breaks. 7MBA and 12MBA which exhibit carcinogenic activity intermediate between that of DMBA and BA induced few CA in the present system. However, the correlation coefficient between the logarithm incidence of aberrant cells and the carcinogenicity index calculated from the data of 9 BA derivatives including both 7MBA and 12MBA was 0.792. The relative mutagenicities of the BA derivatives with TA100 in the presence of hepatic S9 from polychlorinated biphenyl (PCB)-treated rats were in the order: BA greater than 7MBA greater than DMBA greater than 12MBA greater than 7EBA greater than EMBA greater than MEBA greater than 12EBA = DEBA = control. The results with TA98 were essentially the same as those with TA100. The results with TA100 in the presence of hepatic S9 from phenobarbital (PB)-treated rats were in the order: DMBA greater than 12MBA greater than 7MBA greater than 7EBA greater than BA greater than EMBA = MEBA greater than 12EBA = DEBA = control. These findings reveal no obvious relation between the mutagenic activities of the BA derivatives with the PCB-S9 or PB-S9 activating systems and their capacities to induce CA or their reported carcinogenicities. The incidence of CA induced by the dihydrodiols implicated as the metabolic precursors of the active diol epoxide metabolites of several of these BA derivatives was also tested. BA 3,4-dihydrodiol, like BA itself, induced few CA. However, the corresponding dihydrodiols of DMBA, 12MBA and 7MBA, induced relatively high levels of CA.(ABSTRACT TRUNCATED AT 400 WORDS)

Alcohols↗
PubMed1988

Expression of the E2 open reading frame of papillomaviruses BPV1 and HPV6b in silkworm by a baculovirus vector.

To produce and characterize the nature of the E2 protein of papillomaviruses, we have developed a system to express the DNA sequence containing an open reading frame (ORF) as a fusion protein in cultured insect cells and silkworms. The DNA fragments of the E2 ORF predicted from the DNA sequence of bovine papillomavirus type 1 and human papillomavirus type 6b were linked to the N-terminal part of polyhedrin gene of the Baculovirus Bombyx mori nuclear polyhedrosis virus (BmNPV) vector. Hybrid proteins composed of polyhedrin protein (52 amino acids) and the E2 proteins of BPV1 (410 amino acids) or HPV6b (346 amino acids) were efficiently produced in B. mori cells and silkworm larvae infected with recombinant viruses. The amount of E2 fusion proteins produced by recombinant viruses was comparable to that of polyhedrin produced by wild type BmNPV. The hybrid proteins were immunologically reactive to antiserum against polyhedrin.

Animals↗