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Biomedical subjects

S Shimizu

Publications and source records attributed to S Shimizu.

At least 487 records · Page 27Linked to original sources

[FAM as a palliative chemotherapy for gastric cancer with bone metastasis].

A 50-year-old male was admitted to our hospital with severe malaise and lumbar pain. He suffered from diffuse bone metastasis of gastric cancer (mod. tub. adenocarcinoma) and DIC. In order to palliate his severe bone pain and bleeding tendency, FAM (5-fluorouracil 600 mg/body day 1, 7, 29, 36; doxorubicin 40 mg/body day 1, 29; and mitomycin C 12 mg/body day 1) combination chemotherapy was used. After administration of FAM therapy, bone pain and bleeding tendency due to DIC disappeared. For three months after initiation of chemotherapy, the patient's quality of life was maintained fairly well. Adverse reactions of FAM therapy were only appetite loss for several days. FAM therapy might be a useful regimen for palliation of bone pain and DIC due to diffuse bone metastasis of gastric cancer.

Adenocarcinoma↗

[A case of Sjögren's syndrome with an eyelid tumor, a so-termed pseudolymphoma of the iacrimal gland].

The female subject, 64 years old, subjectively noticed a mild dryness of the eyes and bilateral, submandibular swelling in 1988. The clinical symptom was mild, and such autoantibody and hyper-gammaglobulinemia as often observed in Sjögren's syndrome were not recognized. However, by judging from the results of gum test (9 mL/10 min), salivary gland scan (Grade 2) and the labial biopsy, we diagnosed the case as Sjögren's syndrome. We then administered prednisolone at 40 mg at the onset of treatment and gradually decreasing the dosage over 3.5 years, and the symptoms improved. As an eyelid tumor in the left eye was noticed in 1991 and began to enlarge, the subject was hospitalized in June of 1992. The biopsy of the tumor (2.0 x 1.7 cm) showed marked polyclonal lymphoproliferation with lymphoid follicles which was determined by immunohistological staining. The case was a patient with a lymphoproliferative lesion from a lacrimal gland which is equal to a so-termed pseudolymphoma. Since there are some reports concerning the transition from pseudolymphoma to malignant lymphoma, this patient should be followed carefully.

Eyelid Neoplasms↗

Coexistence of psoriasis and an unusual IgG-mediated subepidermal bullous dermatosis: identification of a novel 200-kDa lower lamina lucida target antigen.

Bullous pemphigoid (BP) is characterized by autoantibodies against 230- and 180-kDa hemidesmosomal antigens located in the most superficial layers of the basement membrane zone (BMZ). Histologically, there is a predominance of eosinophils in the infiltrate. In a psoriatic patient, we identified an unusual autoimmune subepidermal bullous eruption which clinically resembled BP, but which was characterized by IgG autoantibodies against a novel 200-kDa lower lamina lucida component. Histologically there was a predominance of neutrophils in the infiltrate. Direct immunofluorescence showed linear immunoglobulin (Ig)G and C3 deposition at the BMZ. The patient's IgG autoantibodies bound exclusively to the dermal side of salt-split normal human skin. Indirect immunogold electron microscopy showed a marked deposition of IgG at the lower lamina lucida and minimal deposition at the hemidesmosomes. Immunoblot analysis identified a unique 200-kDa autoantigen in dermal extracts and a faint band of the 230-kDa BP antigen in epidermal extracts. The patient responded dramatically well to cyclosporin A. Although the patient's serum also reacted slightly with the 230-kDa BP antigen, there were significant findings different from the usual immunopathological changes of BP. These included finding a novel 200-kDa lower lamina lucida target antigen, the binding of IgG autoantibodies exclusively to the dermal side of the split skin and a predominance of neutrophils in blister infiltrate. The IgG autoantibodies against the 200-kDa lamina lucida target antigen seemed to play a major role in the pathogenesis of this unique autoimmune subepidermal dermatosis.

Aged↗

[Extracranial vertebral artery aneurysm complicating Klippel-Feil syndrome: case report].

The Klippel-Feil syndrome is one of the spinal malformations characterized by fusion of the cervical vertebrae. It is well known that the malformation can cause some neurologic disorders. However, an aneurysm in the vertebral artery associated with the Klippel-Feil syndrome is extremely rare, with only one case having been reported in the literature. We present a 39-year-old female with a sudden onset of disturbed consciousness. Lateral cervical x-ray films showed the Klippel-Feil syndrome and hypermobility between C1 and C2. MRI showed multiple infarctions in the posterior circulation, including bilateral thalami. Right vertebral angiogram identified the extracranial vertebral artery aneurysm as the source of the emboli. The patient gradually recovered with conservative therapy. The aneurysm was thought to be produced by chronic arterial trauma secondary to excessive movement between C1 and C2. We conclude that an extracranial vertebral artery aneurysm is a serious complication in a patient with the Klippel-Feil syndrome.

Adult↗

[DNA subtraction in situ hybridization--new approaches of detecting genetic defects in surgical pathology specimens].

A novel in situ histochemical method of screening genetic alterations of human malignant cells was reported. The method is based on subtraction in situ hybridization of whole genomic DNA from a healthy volunteer or DNA extracted from non-neoplastic tissues. The method can widely examine the possible DNA defects in situ without employing specific probes employing colorimetric reaction in routinely processed surgical pathology materials, i.e. 10% formalin-fixed and paraffin embedded tissue sections. Results can be correlated with histopathological findings. In this report, we also describe the results on genetic alterations of human esophageal squamous cell carcinoma, using this DNA subtraction in situ hybridization.

Carcinoma, Squamous Cell↗

Occurrence of a furan fatty acid in marine bacteria.

A fatty acid containing a furan ring was detected in the cellular lipids of marine bacteria, Shewanella putrefaciens, Marinomonas comunis, Enterobacter agglomerans, Pseudomonas fluorescens, etc., which were isolated from the intestinal liquor of fishes. Analytical data indicated that the fatty acid was 10,13-epoxy-11-methyloctadeca-10, 12-dienoic acid. Therefore, we propose that furan fatty acids detected in marine fish are derived not only from marine plants but also from intestinal bacteria of fishes.

Animals↗

Preparation of 13C-labeled polyunsaturated fatty acids by an arachidonic acid-producing fungus Mortierella alpina 1S-4.

Three types of 13C-labeled polyunsaturated fatty acids (PUFAs) were produced in mycelia of an arachidonic acid-producing fungus, Mortierella alpina 1S-4, when grown with 13C-labeled glucose or fatty acid methyl esters. We analyzed them by negative-ion fastatom bombardment mass spectrometry. (i) PUFA in mycelia grown with [1-(13)C]glucose or [2-(13)C]glucose was a mixture of molecules containing zero to six labeled carbons. The content of 13C in the total carbon atoms of PUFA, such as arachidonic (20:4 omega 6), dihomo-gamma-linolenic (20:3 omega 6), gamma-linolenic (18:3 omega 6), and linoleic (18:2 omega 6) acids, in the mycelia grown with [1-(13)C]-glucose or [2-(13)C]glucose was about 11 or 15%, respectively. More than 80% of these PUFA had more than one 13C atom. (ii) When the fungus was grown with [U-13C]glucose, the content of PUFA molecules, all carbons of which were 13C-labeled, was about 20%. The percentage of 13C in PUFA from [U-13C]glucose was 78-83%, over 98% of which had more than one 13C atom. The 13C atoms in the labeled fatty acids formed from 13C-labeled glucose were thought to be distributed at random by a two carbon-unit. (iii) The 13C atom of PUFA in mycelia grown with 1-(13)C-labeled fatty acid methyl esters was highly localized. More than half of the 20:4 omega 6 molecules had only one 13C atom at C-3, C-5, or C-7 when the fungus was grown with methyl [1-13c]stearate, methyl [1-(13)C]palmitate, or methyl [1-(13)C]-myristate, respectively.

Arachidonic Acid↗

AG dinucleotide insertion in a patient with chronic granulomatous disease lacking cytosolic 67-kD protein.

The 67-kD cytosolic protein (p67-phox) is an essential component of the superoxide-generating system in phagocytes, and its defect is known to cause chronic granulomatous disease (CGD). We sequenced p67-phox cDNA from one of seven patients found in Japan and his parents. In the patient's cDNA, homozygous AG dinucleotide insertion at position 399 (or 401) was found together with three other homozygous substitutions in a coding region (A-542 to G, T-895 to C and A-983 to G) compared with the sequence reported for HL-60 cells. In cDNA from his parents, the AG insertion was found to be heterozygous. In contrast, the other three substitutions were found homozygously in his father's specimen and the latter two in his mother's specimen. The substitution of A-542 to G was heterozygous in his mother's cDNA. The AG insertion would induce a frame shift and bring about a stop codon at the position of 433. However, the other three differences would give insignificant changes for the protein function, if any, because the substitutions of A-542 to G and A-983 to G result in the conservative amino acid transitions, ie, Lys-180 to Arg and Lys-327 to Arg, and that of T-895 to C no amino acid change. Neutrophils from the patients completely lacked superoxide generating activity whereas those from his parents generated substantial amounts of superoxide anion upon stimulation. Thus, it is concluded that the AG dinucleotide insertion is responsible for the disease in this patient.

Adult↗

Irradiation increases manganese superoxide dismutase mRNA levels in human fibroblasts. Possible mechanisms for its accumulation.

Irradiation induces the production of superoxide radicals (O2.-), which play an important causative role in radiation damage. Manganese superoxide dismutase (MnSOD) is a mitochondrial enzyme involved in scavenging O2..-. This study examined MnSOD gene regulation by irradiation in WI38 human fibroblasts. Unstimulated fibroblasts constitutively expressed MnSOD activity and mRNA; irradiation markedly increased MnSOD activity and mRNA levels. The increase in MnSOD transcripts by irradiation was both time- and dose-dependent. WI38 fibroblasts constitutively produce low levels of interleukin-1 (IL-1). The induction of MnSOD mRNA by irradiation was partially blocked by anti-IL-1 antibodies, and treatment of cells with IL-1 also increased MnSOD mRNA levels. Inhibition of the cyclo-oxygenase pathway with indomethacin augmented the induction MnSOD mRNA by irradiation and prostaglandin E2 inhibited the accumulation of MnSOD mRNA by irradiation. Transcriptional run-on analysis showed that irradiation increased the rate of MnSOD transcription 2-fold. Stability studies of MnSOD mRNA in these cells showed that the half-life increased from < 1.5 h in unirradiated cells to > 4 h in irradiated cells. These results suggest that induction of the MnSOD gene after irradiation is regulated, at least in part, by IL-1 production and that increased levels of MnSOD transcripts also occur through a pathway of endogenous prostaglandin E2 production. Our data indicate that the increase in MnSOD mRNA observed after irradiation occurs through both transcriptional and post-transcriptional mechanisms.

Cells, Cultured↗

omega-Hydroxylation of docosahexaenoic acid or arachidonic acid in human colonic well differentiated adenocarcinoma homogenate.

Human colonic well differentiated adenocarcinoma homogenate was incubated with NADPH and docosahexaenoic acid (22:6(n-3)) or arachidonic acid (20:4(n-6)) as a substrate. On a selected ion monitoring chromatogram obtained with reversed phase-high-performance liquid chromatography thermospray mass spectrometry, omega-hydroxydocosahexaenoic acid (omega-HDHE) or omega-hydroxyeicosatetraenoic acid (omega-HETE) from an incubation mixture of the homogenate was detected in significant amount, compared to that from a colonic region remote from the carcinoma. In contrast, epoxydocosapentaenoic acids and the dihydroxy derivatives from 22:6(n-3) or epoxyeicosatrienoic acids and the dihydroxy derivatives from 20:4(n-6) were detected in low amounts, compared to that from a colonic region remote from the carcinoma. The results suggest that highly active NADPH-dependent omega-oxidations of polyunsaturated fatty acids occur in colonic adenocarcinoma homogenate.

Adenocarcinoma↗

Purification and characterization of two forms of cytochrome b5 from an arachidonic acid-producing fungus, Mortierella hygrophila.

Two forms of cytochrome b5 have been purified from the microsomes of an arachidonic acid-producing fungus, Mortierella hygrophila IFO 5941, after detergent solubilization. They have monomeric molecular masses of about 16 kDa and 19 kDa. Their absorption spectra are similar to those of mammalian cytochrome b5s. Their amino acid compositions show some similarity to those of mammalian cytochrome b5s, but the contents of some amino acids (glycine, alanine, aspartic acid + asparagine, glutamic acid + glutamine, arginine, proline, histidine, leucine and lysine) are unique to the cytochrome b5s of M. hygrophila. Some of their internal peptide sequences also show close homology with those of some mammals (approx. 65 to 67%), while some others show no or little homology. The addition of various acyl-CoAs to NADH-reduced microsomes caused an abrupt shiftdown of the steady state reduction level of cytochrome b5. This indicates the increased utilization of electrons for the desaturation process and may suggest that the cytochrome b5s of this fungus actually take part in its microsomal desaturation system for polyunsaturated fatty acid biosynthesis as electron carriers.

Amino Acid Sequence↗

Prevention of hypoxia-induced cell death by Bcl-2 and Bcl-xL.

The proto-oncogene bcl-2, isolated from the t(14;18) chromosomal breakpoint in follicular B-lymphoma, and a bcl-2-related gene bcl-x (ref. 4) prevent apoptotic cell death induced by various treatments. Although a mechanism has been proposed that involves Bcl-2 activity on reactive oxygen species (ROS), expression of Bcl-2 or Bcl-xL prevents cell death induced by withdrawal of oxygen (hypoxia), which drastically decreases the net formation of oxygen free radicals and does not increase oxidized lipid, protein or DNA. Furthermore, neither ROS scavenger nor inhibitor of ROS scavenger affects cell death, regardless of the expression of Bcl-2 or Bcl-xL. Thus our data suggest that Bcl-2 and Bcl-xL exert an anti-cell death function by a mechanism other than regulation of ROS activity.

Animals↗

High-performance liquid chromatography-thermospray mass spectrometry of omega-carboxyleukotriene B4 and omega-hydroxyleukotriene B4 from an incubation mixture of human colonic well-differentiated adenocarcinoma homogenate.

A method for the analysis of omega-carboxyleukotriene B4 and omega-hydroxyleukotriene B4 in human colonic carcinoma homogenate is described. The hydroxy groups of the leukotriene metabolite were acetylated by acetic anhydride, and the mixture was partially purified on a Sep-Pak C18 cartridge and analysed by reversed-phase HPLC-thermospray MS. Generally, the base ion, [MH-2(60)]+, is produced through elimination of two acetic acid (60 mass units) molecules from the protonated molecular ion. On selected-ion monitoring, standard curves for omega-carboxy- or omega-hydroxyleukotriene B4 showed a linear relationship over the range 72-1500 pmol. The assay based on selected-ion monitoring was applied to an extract from human colonic carcinoma homogenate. When a homogenate of human colonic well-differentiated adenocarcinoma was incubated with NADPH and leukotriene B4 (60.6 nmol) as a substrate, the conversion of precursor leukotriene B4 to omega-carboxyleukotriene B4 or omega-hydroxyleukotriene B4 was 0.33 or 3.17%, respectively. Based on these results, it is suggested that carcinoma cells themselves or leukocytes at the hostsite in a region of human colonic well-differentiated adenocarcinoma are performing omega-oxidation through NADPH-dependent omega-hydroxylation of leukotriene B4.

Adenocarcinoma↗