Biomedical subjects
N Shimizu
Publications and source records attributed to N Shimizu.
[Five cases of pulmonary thromboembolism after chest surgery].
The incidence of pulmonary thromboembolism after chest surgery is increasing. Five cases of it in recent two years were described. Four cases were lung cancer, and the other was myasthenia gravis. All lung cancer cases were after left lobectomy, and the findings of thromboembolism were mainly detected in right lung. Though hypocapnia is characteristic of pulmonary thromboembolism, arterial blood gas tests did not show it in all cases. Slight hypoxemia and arrhythmia are noteworthy signs of pulmonary thromboembolism after chest surgery. As thrombolytic and anticoagulation therapy, urokinase and heparin were very useful in four of five cases. Four patients made a rapid recovery from pulmonary thromboembolism, but one died of cerebral hemorrhagic infarction. The other patient did not recover in spite of intense medication, extracorporeal membrane oxygenation, and pulmonary embolectomy. To prevent pulmonary thromboembolism after chest surgery, appropriate countermeasures should be considered.
New animal model of glandular stomach carcinogenesis in Mongolian gerbils infected with Helicobacter pylori and treated with a chemical carcinogen.
In 1994 WHO/IARC concluded that "Helicobacter pylori is a definite carcinogen" based on epidemiological studies, but there have been few reports demonstrating a relation between H. pylori and stomach cancer in animal models. We have succeeded in producing adenocarcinomas in the glandular stomachs of Mongolian gerbils with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) or N-methyl-N-nitrosourea as carcinogens and hope to establish an experimental stomach carcinogenesis model using H. pylori. Male Mongolian gerbils, 7 weeks old, were infected with H. pylori followed by MNNG administration at a concentration of 100ppm administration or treated with MNNG at a concentration of 300ppm in their drinking water followed by inoculation with H. pylori. They were then killed sequentially, and their excised stomachs underwent microbiological and histopathological examinations. H. pylori were detected in all infected gerbils. Hyperplastic change of pyloric mucosa was observed with high 5-bromo-2'-deoxyuridine incorporation in affected animals. H. pylori infection persists on administration of MMNG and enhances glandular stomach proliferation in Mongolian gerbils. Whether long-term colonization promotes carcinogenesis in the glandular stomach of Mongolian gerbils is a matter of great interest.
[Usefulness of pharmacokinetic modulating chemotherapy (PMC) for the postoperative adjuvant therapy of colorectal carcinoma: a preliminary report].
Pharmacokinetic modulating chemotherapy (PMC) using oral UFT and continuous venous 5-FU infusion was administered to 22 resectable patients with Dukes' B2-D colorectal carcinomas. The regimen was arranged as follows: Group A (n = 12) UFT 300-450 mg/day, 5 days a week and 5-FU 440-600 mg/m2/24 hr (750-1,000 mg/body/24 hr) once a week, Group B (n = 10), UFT less than 300 mg/day, 5 days a week, and/ or 5-FU less than 440 mg/m2/24 hr (750 mg/body/ 24 hr) once a week. The control group (Group C, n = 26) was selected at random from among non-PMC cases matched for other background factors and in which surgery had been performed during the past 4 years. Fifteen out of 26 patients in Group C were treated with 5-FU masked compounds orally. The cumulative 2 year recurrent rates of Groups A, B and C were 8.3%, 52.0% and 50.0%, respectively; the rate of Group A was significantly lower than that of Group B (p < 0.05). Four patients who suffered from PMC-related side effects of grade 1-2 wanted to decrease their dosage of UFT and/or 5-FU. They were registered in Group B. These results suggest that the regimen of Group A was advantageous in improving the prognosis after resection of Dukes' B2-D colorectal carcinoma.
[First successful bilateral living-donor lobar lung transplantation in Japan].
No successful lung transplantation has been reported in Japan until recently when we performed the first successful bilateral living-donor lobar lung transplantation. A 24-year-old woman with primary ciliary dyskinesia began experiencing severe respiratory insufficiency and required mechanical ventilation. On October 28, 1998, she underwent bilateral living-donor lobar transplantation, receiving her sister's lower right lobe and her mother's left lower lobe under cardiopulmonary bypass. The patient was discharged from the hospital 61 days after transplantation. Six months postoperatively, she has returned to normal life and is able to carry out daily activities. She is in good physical condition with a vital capacity of 1.77 L.
Fluorodeoxyglucose positron emission tomography scan of prostate cancer bone metastases with flare reaction after endocrine therapy.
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Targeted in vivo delivery of therapeutic gene into experimental squamous cell carcinomas using anti-epidermal growth factor receptor antibody: immunogene approach.
The "Fab immunogene" is a novel gene transfer vehicle in which the Fab fragment of anti-human epidermal growth factor (EGF) receptor antibody B4G7 is conjugated with poly-L-lysine to form an affinity complex with DNA. It was developed to target delivery of therapeutic genes into EGF receptor-hyperproducing tumor cells. Various characteristic features of the immunogene have been documented (Chen et al., 1998). Here we add further evidence to prove that in vitro transfer of beta-galactosidase/Fab immunogene is exclusively to EGF receptor-positive cells and that the herpes simplex virus thymidine kinase (TK)/Fab immunogene induces substantial suicide effects on A431 tumor cells when treated together with ganciclovir. The in vivo specificity of the immunogene transfer was examined using A431 tumor-bearing nude mice. When these nude mice were injected intraperitoneally with the chloramphenicol acetyltransferase (CAT)/Fab immunogene, CAT DNA was detected in the tumors as well as in liver and kidney but not brain, whereas CAT mRNA and enzyme activity were detected only in the tumors. Local and intraperitoneal injection of the TK/Fab immunogene and subsequent administration of ganciclovir effectively suppressed the growth of A431 tumors transplanted on the backs of nude mice. These observations suggest a possible application of the Fab immunogene system in cancer gene therapy.
Sperm-activating proteins obtained from the herring eggs are homologous to trypsin inhibitors and synthesized in follicle cells.
The activation of sperm motility by the egg is an ubiquitous phenomenon in the animal kingdom, but the molecules by which the egg activates sperm motility have been clarified in only a few invertebrate species. In the Pacific herring, Clupea pallasii, mature unfertilized eggs release the sperm-activating proteins which are prerequisite to successful fertilization. Complementary DNA clones encoding herring sperm-activating proteins were isolated from a herring ovarian complementary DNA library and amino acid sequences were deduced. The herring sperm-activating protein(s) is a secretory product(s) with a strong homology to Kazal-type trypsin inhibitors, such as mammalian acrosin inhibitors. The sperm-activating proteins were globally distributed in the outermost layer of the egg chorion and its gene was found to be expressed in the follicle cells which surround developing oocytes. These results suggest that in the Pacific herring, trypsin inhibitor-like proteins are synthesized in the follicle cells, secreted, accumulated in the egg chorion during oocyte development, and released into the milieu at spawning to activate the motility of spermatozoa at the time of gamete interaction.
Structural organization and chromosomal localization of the human hepatocyte growth factor activator gene--phylogenetic and functional relationship with blood coagulation factor XII, urokinase, and tissue-type plasminogen activator.
The organization and structure of the gene coding for hepatocyte growth factor activator (HGFA) have been determined by isolation of unique clones from a human genomic library. These clones were characterized by restriction mapping, Southern blotting and DNA sequencing. The complete sequence of the gene was determined and found to span about 7.5 kilobases of DNA and consist of 14 exons separated by 13 introns. The coding region of HGFA consists of multiple putative domains that are homologous to those observed in blood coagulation factor XII (FXII). These regions were found as separate exons in the gene, and the exon/intron arrangement was similar to that of FXII, suggesting that the genes for HGFA and FXII have arisen through gene duplication events from a common ancestral gene. The major transcription initiation site is located 75 bp upstream of the translational start codon. The gene was mapped to chromosome 4p16, using spot-blot hybridization on sorted chromosomes and fluorescence in situ hybridization on metaphase chromosome spreads. The phylogenetic and functional relationships between HGFA and FXII as well as urokinase and tissue-type plasminogen activator are discussed.
Pb isotopic variability in melt inclusions from oceanic island basalts, polynesia
Previous studies have suggested that melting processes are responsible for the trace element variability observed in olivine-hosted basaltic melt inclusions. Melt inclusions from three individual lava samples (two from Mangaia, Cook Islands, and one from Tahaa, Society Islands) have heterogeneous Pb isotopic compositions, even though the erupted lavas are isotopically homogeneous. The range of Pb isotopic compositions from individual melt inclusions spans 50 percent of the worldwide range observed for ocean island basalts. The melt inclusion data can be explained by two-component mixing for each island. Our data imply that magmas with different isotopic compositions existed in the volcanic plumbing system before or during melt aggregation.
Molecular cloning of a novel putative Ca2+ channel protein (TRPC7) highly expressed in brain.
We have isolated cDNA clones for a novel human protein, TRPC7 (transient receptor potential-related channels), which consists of 1503 amino acid residues from the fetal brain and caudate nucleus cDNA libraries. Northern blot analysis indicated that the TRPC7 gene is highly expressed as a 6.5-kb transcript in brain. The TRPC7 protein has significant homology with Caenorhabditis elegans hypothetical proteins T01H8.5, C05C12.3, and F54D1.5 and with Drosophila and human transient receptor potential (trp) proteins. The TRPC7 protein has seven putative transmembrane domains that probably constitute a Ca2+ channel as in the above-mentioned proteins. Genomic sequencing revealed that the TRPC7 gene consists of 32 exons spanning approximately 90 kb. The TRPC7 gene was mapped between D21S400 and D21S171 on human chromosome 21q22.3, 14 kb distal to a NotI site in D21S400. This novel TRPC7 gene could be a candidate gene for genetic disorders such as bipolar affective disorder, nonsyndromic hereditary deafness, Knobloch syndrome, and holoprosencephaly, which were mapped to this region.
Collagen abnormalities in the spinal cord from patients with amyotrophic lateral sclerosis.
During the last 10 years, we have demonstrated morphological and biochemical abnormalities of skin extracellular matrices in amyotrophic lateral sclerosis (ALS). However, currently little is known concerning collagen of the spinal cord in ALS. We measured the amount of collagen and characterized collagen at light and electron microscopic levels in posterior funiculus, posterior half of lateral funiculus and anterior horn of cervical enlargement of the spinal cord obtained from ten patients with ALS, 11 patients with other neurologic diseases (control group A), and ten patients without neurologic ones (control group B). In posterior half of lateral funiculus and anterior horn, (1) by light microscopy, there was no significant difference in vessel wall area between ALS patients and control groups A and B; (2) ultrastructurally, collagen bundles were more fragmented and widely separated, and the fibrils were randomly oriented in the perivascular space of capillaries in ALS patients, which were not observed in any areas of control groups or in posterior funiculus of ALS patients; and (3) the collagen contents in ALS were significantly lower (P<0.001 and P<0.001, respectively) than those in control groups A and B. Fragmented and widely separated collagen bundles in the interstitial tissue surrounding capillaries and markedly decreased amount of collagen in posterior half of lateral funiculus and in anterior horn of ALS could be related to the degeneration of the upper and lower motor neurons in the spinal cord in ALS, that is, selective neuronal vulnerability in ALS.
Identification of two novel 5' noncoding exons in human MNB/DYRK gene and alternatively spliced transcripts.
Previously, the comparison of human MNB/DYRK cDNA sequences with publicly available genomic DNA sequence made a conclusion that MNB/DYRK gene consists of 11 exons spanning 100 kb. Here we found a novel human MNB/DYRK cDNA clone that has the 5' end different from any of those reported MNB/DYRK cDNAs. The 5' end of this cDNA resides in a CpG island associated with the NotI linking clone LL390 that is located more than 50 kb upstream of the exon that contains an initiation codon ATG. Northern blot analysis indicated that almost all the MNB/DYRK transcripts start from the newly identified 5'-noncoding exon. PCR amplification of cDNAs from various human tissues indicated that some mRNAs contain an additional noncoding exon of 76 bp next to the 5'-end exon and there are at least three types of MNB/DYRK mRNAs containing alternatively spliced 5' exons including two novel exons. We now conclude that human MNB/DYRK gene consists of 13 exons (not 11 exons) spanning about 150 kb (not 100 kb).
Ciliary neurotropic factor in skin biopsies of patients with amyotrophic lateral sclerosis.
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Point mutations (Thr240Arg and Gln311Stop) [correction of Thr240Arg and Ala311Stop] in the Parkin gene.
Autosomal recessive juvenile parkinsonism (AR-JP) is a distinct clinical and genetic entity characterized by selective degeneration of nigral neurons. Recently, the parkin gene responsible for AR-JP has been identified. To date, we found two different deletional mutations including single and multiple exonic deletions. In the present study, we identified two types of point mutations (Thr240Arg and Gln311Stop) involving exons 6 and 8 in the parkin gene of the AR-JP patients from two Turkish families. This is the first report on point mutations for the parkin gene. Furthermore, the Thr240Arg mutation was located on a consensus sequence for the site of phosphorylation by casein kinase II. Identification of its mutation provides an important clue as to the role of the Parkin protein in degeneration of the substantia nigra in the brain of AR-JP patients.
Overproduction and immuno-affinity purification of myelin proteolipid protein (PLP), an inositol hexakisphosphate-binding protein, in a baculovirus expression system.
Myelin proteolipid protein (PLP) is a major integral membrane protein of central nervous system myelin and is considered to play a significant role in myelination. PLP has a four-transmembrane structure, judging from the hydropathy profile. In addition, it has InsP6 binding activity. Here, we have succeeded in producing PLP in large quantities of 3.9 pg/cell (6 mg/L) by using a baculovirus expression system and developing an efficient purification method, maintaining InsP6 binding activity. The recombinant PLP (rPLP) was purified by ion-exchange and immunoaffinity chromatography in a nonorganic solvent. The final yield of purified rPLP was 36%. The Kd and Bmax values for the InsP6-PLP binding were 55 nM and 33 pmol/microgram protein, respectively. The Kd value of purified rPLP is equal to that of mouse brain PLP. These results indicate that purified rPLP keeps its native conformation and binds InsP6 in an almost one-to-one ratio.
The gene for death agonist BID maps to the region of human 22q11.2 duplicated in cat eye syndrome chromosomes and to mouse chromosome 6.
Cat eye syndrome (CES) is associated with a duplication of a segment of human chromosome 22q11.2. Only one gene, ATP6E, has been previously mapped to this duplicated region. We now report the mapping of the human homologue of the apoptotic agonist Bid to human chromosome 22 near locus D22S57 in the CES region. Dosage analysis demonstrated that BID is located just distal to the CES region critical for the majority of malformations associated with the syndrome (CESCR), as previously defined by a single patient with an unusual supernumerary chromosome. However, BID remains a good candidate for involvement in CES-related mental impairment, and its overexpression may subtly add to the phenotype of CES patients. Our mapping of murine Bid confirms that the synteny of the CESCR and the 22q11 deletion syndrome critical region immediately telomeric on human chromosome 22 is not conserved in mice. Bid and adjacent gene Atp6e were found to map to mousechromosome 6, while the region homologous to the DGSCR is known to map to mouse chromosome 16.
Molecular cloning, expression, and purification of undecaprenyl diphosphate synthase. No sequence similarity between E- and Z-prenyl diphosphate synthases.
Cloning of the gene for undecaprenyl diphosphate synthase was successful, providing the first primary structure for any prenyltransferase that catalyzes Z-prenyl chain elongation. A genomic DNA library of Micrococcus luteus B-P 26 was constructed in Escherichia coli, and the recombinant clones were grown on nylon membranes. The membrane was incubated directly by floating it on a reaction mixture containing radiolabeled isopentenyl diphosphate, nonlabeled farnesyl diphosphate, and Mg2+. Only the clones harboring plasmids encoding prenyltransferases could take up the substrates to synthesize and accumulate radiolabeled products inside the cells in amounts large enough to be detectable by autoradiography. Four positive colonies were found among about 4,000 bacterial colonies of the genomic DNA library. Two of them carried the gene for undecaprenyl diphosphate synthase, which catalyzes the Z-prenyl chain elongation, and the others carried the (all-E)-hexaprenyl diphosphate synthase genes (hexs-a and hexs-b; Shimizu, N., Koyama, T., and Ogura, K. (1998) J. Bacteriol. 180, 1578-1581). The undecaprenyl diphosphate synthase, which had a predicted molecular mass of 28.9 kDa, was overproduced in E. coli cells by applying a soluble expression system, and it was purified to near homogeneity. The deduced primary structure of the Z-prenyl chain-elongating enzyme is totally different from those of E-prenyl chain-elongating enzymes, which have characteristic conserved regions, including aspartate-rich motifs.