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Biomedical subjects

N Miwa

Publications and source records attributed to N Miwa.

At least 55 records · Page 3Linked to original sources
PubMed1996

Promotive action of acylated ascorbate on cellular DNA synthesis and growth at low doses in contrast to inhibitory action at high doses or upon combination with hyperthermia.

Effects of 6-O-palmitoyl ascorbate (ascorbate) developed to increase the antitumour activity of ascorbic acid on DNA synthesis and proliferation of Ehrlich ascites tumour cells were investigated. Treatment of the cells with the acylated ascorbate at 25-50 microM for 1 h resulted in no effect on DNA synthesis, assayed by pulse incorporation of [3H]thymidine after a culture period of 20 h, but led to 49%-87% enhanced DNA synthesis after 4 days, suggesting that long-term culture is required for promotion by ascorbate to occur. At a dose as high as 75 microM acylated ascorbate, however, cellular DNA synthesis was 64% inhibited after 20 h and 99% after 4 days. The results suggest that acylated ascorbate exhibits a dual action on DNA synthesis: promotion at low doses and inhibition at high doses, both of which are potentiated in a time-dependent manner. In contrast to the above-mentioned results at 37 degrees C, acylated ascorbate at 25-75 microM inhibited but did not promote DNA synthesis at 42 degrees C whatever the culture period. Similar results were exhibited when proliferation of cells cultured for a long period was investigated. At 37 degrees C, 50 microM acylated ascorbate increased the number of the cells to 3.6 times the control values after 8 days and to 1.9 times after 11 days; in contrast, a 75-microM dose decreased the cell number considerably. Combination with hyperthermia (42 degrees C) suppressed the increase and cell growth was completely inhibited at 75 microM.

Acylation↗
PubMed1996

Nested polymerase chain reaction for detection of low levels of enterotoxigenic Clostridium perfringens in animal feces and meat.

A rapid and sensitive method for detecting enterotoxigenic Clostridium perfringens in animal feces and meat is described. The method consists of a combination of nested polymerase chain reaction (PCR) with enrichment culture of the sample. In the PCR, two pairs of oligonucleotide primers homologous to the C. perfringens enterotoxin (CPE) gene were used: the first primer pair amplified a 425-bp fragment and the second one amplified a 199-bp fragment within the fragment amplified by the first PCR. When the specificity and sensitivity of nested PCR in the detection of the CPE gene of isolated C. perfringens were compared with those of the single PCR, the former amplified specifically the 199-bp fragment and the sensitivity was about 10(3)-fold higher that that of the latter. The nested PCR combined with enrichment culture was applied to detecting the CPE gene in samples inoculated artificially with enterotoxigenic C. perfringens. This method detected within 22-26 hr the CPE gene in samples of animal feces and meat inoculated with fewer than 10(1) CFU/g of enterotoxigenic C. perfringens. When the method was applied to detection of indigenous enterotoxigenic C. perfringens in cattle feces, pig feces, beef and pork, C. perfringens was found in one case (10%) of 10 cattle fecal samples, and the PCR-amplified product corresponded to the fragment of the CPE gene in restriction endonucleases digestion pattern.

Animals↗
PubMed1996

[Role of intercellular adhesion molecule (ICAM)-1 in the interaction between glomerular endothelial cells and granulocytes].

The present study was designed to investigate the role of intercellular adhesion molecule (ICAM)-1 in the interaction between glomerular endothelial cells (GEN) and granulocytes. Expression of ICAM-1 was promoted after stimulation with tumor necrosis factor (TNF)-alpha. This effect was dose- and time-dependent. Granulocytes attached to GEN in accordance with the increased expression of ICAM-1 on the cells stimulated with TNF-alpha. In addition, the adhesion of granulocytes to activated GEN with TNF-alpha stimulated specific [51Cr] release from the monolayers. Furthermore, monoclonal antibodies to TNF-alpha dose-dependently inhibited the adhesion of granulocytes to activated GEN. In summary, ICAM-1 is related to the glomerular endothelial cell injury induced by granulocytes activated with TNF-alpha, suggesting that ICAM-1 may play a role in the initiation of certain types of glomerulonephritis with granulocyte infiltration.

Animals↗
PubMed1995

Involvement of adhesion molecules in glomerular endothelial cell injury induced by PMA-stimulated lymphocytes.

Adhesion of lymphocytes to glomerular endothelial cells might be a critical step in the development of acute and chronic glomerulonephritis. The protective effect of anti-CD11a and anti-intercellular adhesion molecule (ICAM-1) antibodies on the cytotoxity elicited by phorbol 12-myristate 13-acetate (PMA)-stimulated lymphocytes was investigated by using cultured bovine glomerular endothelial cells (GEN). Both anti-CD11a and CD18 antibodies inhibited GEN injury induced by the activated lymphocytes in a dose-dependent manner. In addition, both antibodies also inhibited the adhesion of the activated lymphocytes to the GEN monolayers. These results suggest that it is important for activated lymphocytes to bind to GEN via adhesion molecules for cytotoxity to be produced by the activated lymphocytes.

Animals↗
PubMed1995

[Glomerular lesion in patients with type II mixed cryoglobulinemia having antibodies to hepatitis C virus].

We report here two cases of mixed cryoglobulinemia showing renal involvement associated with hepatitis C virus (HCV) infection. The subjects were 62- and 63-year-old males. Both patients presented with purpura on the legs, which was diagnosed as allergic vasculitis by skin biopsy. Case 1 followed a clinical course of progressive nephrotic syndrome with mild hematuria. He also had diabetes mellitus and hypertension. In contrast, case 2 showed only mild hematuria without proteinuria at the time of the renal biopsy. Both cases had immunological disarrangements, such as severe hypocomplimentemia and seropositive rheumatic factor. Recently, it was reported that patients with type II mixed cryoglobulinemia had HCV seropositivity, and revealed membranoproliferative glomerulonephritis. These facts strongly suggested that renal lesions are the result of direct damage mediated by cryoglobulinemia and an activated complement pathway through an immune complex mechanism related to HCV.

Antibodies, Viral↗
PubMed1995

Expression of intercellular adhesion molecule-1 on cultured glomerular endothelial cells by pro-inflammatory cytokines and lipopolysaccharide.

Infiltration of leukocytes and mononuclear cells into the glomeruli is an early pathological finding in human and experimental glomerulonephritis. However, the cellular and molecular basis for cell infiltration into the glomeruli is not yet completely understood. In addition, there is little information on the expression of intercellular adhesion molecule-1 (ICAM-1) on glomerular cells. In the present study, we investigated the expression of ICAM-1 on cultured bovine glomerular endothelial cells (GEN) and its regulation by the pro-inflammatory cytokines, interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1) and lipopolysaccharide (LPS). Immunocytochemical staining showed that ICAM-1 molecules were constitutively expressed on the surface of GEN. In flow cytometric and ELISA analyses, ICAM-1 molecule expression on GEN was significantly upregulated by IL-1 beta, MCP-1 and LPS in a dose-dependent manner, but not by IL-6. LPS was the most potent inducer of ICAM-1 molecule expression on GEN. The effects of IL-1 beta, MCP-1 and LPS were observed as early as 4 h and reached a maximal level by 18 h. These results suggest that ICAM-1 on GEN can participate in the infiltration of mononuclear cells into glomeruli in human and experimental glomerulonephritis.

Animals↗
PubMed1995

Enhanced inhibitory effects of hyperthermia combined with ascorbic acid on DNA synthesis in Ehrlich ascites tumor cells grown at a low cell density.

Effects of hyperthermia and cell densities on inhibitory activity of ascorbic acid on DNA synthesis in Ehrlich ascites tumor cells were studied. When cells at a low density of 5 x 10(3)/ml were treated with 75 microM ascorbic acid for 1 h, DNA synthesis was inhibited after treatment at 37 degrees C and the inhibition was significantly enhanced at 42 degrees C. At a cell density as high as 1 x 10(5)/ml, however, inhibition did not occur at 37 degrees C or 42 degrees C. In contrast, dehydroascorbic acid was inactive even at a low cell density under similar conditions. Inhibitory effects of ascorbic acid on DNA synthesis were also markedly enhanced by treatment at 40 degrees C. DNA synthesis was not inhibited in the absence of the drug. Furthermore, mice transplanted with cells treated with a combination of 75 microM ascorbic acid and hyperthermia at 42 degrees C, considerably prolonged their survival time in comparison with untreated cells. Addition of ascorbic acid to hyperthermia is suggested to be an advantageous treatment for cancer.

Animals↗
PubMed1995

[Preoperative plasmapheresis for lung cancer with multiple myeloma].

A 66-old-male admitted to our hospital was diagnosed multiple myeloma (IgA kappa type, Durie & Salmon stage IIIA) and squamous cell lung cancer (c-T2N0M0 stage I). The function of platelets was within a normal range (11.7 x 10(4)/mm3 and the bleeding time of two minutes), but the function of coagulation was reduced (prothrombin time, 13.1 seconds; activating prothrombin time, 45.1 seconds; and antithrombin III, 65%). The hyperviscosity syndrome was anticipated because of high IgA M protein (6,551 mg/dl). Plasmapheresis with 800 ml of fresh frozen plasma was performed before the left lower pulmonary lobectomy and R1 lymph node dissection. Then the function of coagulation was improved (prothrombin time, 12.6 seconds; activating prothrombin time, 31.3 seconds; and antithrombin III, 75%). IgA M protein was also decreased to 4,696 mg/dl. Postoperative bleeding necessitated a second thoracotomy. The cause of postoperative bleeding was the ablasion of the pleural adhesion due to tuberculous pleuritis as well as bleeding tendency of multiple myeloma. The plasmapheresis performed in this case did not fully improve the bleeding tendency. Cases of cancer complicated with multiple myeloma have been increasing and if an operation is needed, plasmapheresis should be considered. The indication and the extent of hematologic restoration to be achieved should be further investigated.

Aged↗
PubMed1995

Differential susceptibility of epidermal keratinocytes and neuroblastoma cells to cytotoxicity of ultraviolet-B light irradiation prevented by the oxygen radical-scavenger ascorbate-2-phosphate but not by ascorbate.

Human or mouse epidermal keratinocytes NHEK or Pam212 was less susceptible to ultraviolet (UV)-B irradiation than mouse neuroblastoma NAs1 cells in culture, undergoing apoptosis-like cell death as shown by cell fragmentation and cell membrane integrity disruption. UV susceptibility was appreciably reduced by the reactive oxygen species (ROS)-scavenger L-ascorbic acid-2-phosphate (Asc2P) endowed with long-lasting functions but not by L-ascorbic acid (Asc) for each cell type. DehydroAsc reduced UV susceptibility of Pam212 or NAs1 established cell lines but not of normal diploid NHEK cells destined to be thereafter submitted to cellular senescence. The susceptibility reduction may not be ascribed to extracellular Asc2P or DehAsc, which was removed by aspirating and/or rinsing upon irradiation after the intracellular channelyzer analysis and dead cell-specific DNA-intercalator ethidium homodimer/fluorometry, respectively. Thus, the three cell types differed in UV susceptibility partly because of their different ROS-scavenging abilities, which may be potently promoted by Asc2P or dehydroAsc but not Asc.

Animals↗
PubMed1994

Inhibition of tumor cell growth by low-boiling-point-saturated fatty acids isolated by molecular distillation and reversed phase liquid chromatography of hydrolysates of uncytotoxic wool grease secreted from sheep sebaceous gland.

We showed that massive growth of mouse Ehrlich ascites carcinoma (EAC) cells was not inhibited by wool grease secreted from the sheep sebaceous gland, whereas wool fatty acids separated by saponification of wool grease was growth-inhibitory. We then fractionated wool fatty acids into 9 fractions using molecular distillation (80-200 degrees C; 1 x 10(-2) mmHg) and found a marked antitumor activity in a low-boiling-point (< 80 degrees C) fraction (MW 200-300; C10-C20), which was further separated by reversed phase liquid chromatography on an octadecylisilica gel column, resulting in 5 fractions. The second most hydrophobic fraction (C8Si-4) obtained was the most growth-inhibitory to EAC cells cultured or implanted into mice, more marked than the antitumor glycopeptide bleomycin. C8Si-4 was suggested to be a mixture of a normal-chain C16-saturated fatty acid and two branched-chain kinds of saturated C16-iso- and C19-anteiso-fatty acids without hydroxyl groups according to gas chromatography-mass spectrographic analysis. Thus low-boiling-point saturated fatty acid moieties in some wool grease molecules were shown to become growth-inhibitory in vitro and in vivo only after released in the free acid form by esterolysis.

Animals↗
PubMed1994

[A case of subperitoneal tuberculosis revealed by abdominal pain during pulmonary tuberculosis treatments].

The case was a 58 year-old female. During hospitalization for the treatment of pulmonary tuberculosis, she complained of pain in the left hypochondriac region. Abdominal CT revealed a mass between the abdominal wall and left lobe of the liver. Metastatic liver carcinoma was suspected by aspiration cytology, but no primary tumor could be identified. Therefore, an exploratory laparotomy was done, and the mass proved to be a subperitoneal tuberculoma. Tuberculous lymphadenitis was also found in lymph nodes of the upper abdominal cavity. Tuberculosis in the abdominal cavity has been rare in recent times in Japan. Therefore, this case provides valuable experience in the differential diagnosis of an abdominal mass.

Abdominal Pain↗
PubMed1993

Human neuroblastoma cells produce the NF-kappa B-like HIV-1 transcription activator during differentiation.

Human neuroblastoma GOTO and IMR32 cells differentiate into neural cells on treatment with 5-BrdU. Here we report that in association with differentiation induced by 5-BrdU, the transcription of HIV-1 was activated in both neuroblastoma cell lines. An NF-kappa B-like factor was also found to be produced in association with the neural cell differentiation of these cells. These results suggest that, during differentiation of neural cells, an NF-kappa B-like factor was produced, and that when the neural cells are infected with HIV-1 the production of NF-kappa B results in activation of transcription of HIV-1. Thus this NF-kappa B-like factor may be involved in the mechanism causing AIDS dementia.

Base Sequence↗
PubMed1993

Angiokeratoma corporis circumscriptum naeviforme with transepidermal elimination.

A 5-year-old Japanese boy visited our clinic for treatment of a dark bluish papulonodular lesion on his right thigh. The histopathology of the lesion indicated angiokeratoma corporis circumscriptum naeviforme. Topical antibiotics were prescribed for occasional bleeding from the site. Frequent bleeding started in April of 1992, when erythema and itching were observed around the angiokeratoma. Histopathology of the lesion showed heavy lymphoid cell infiltration around dilated capillaries and irregular acanthosis engulfing dilated capillaries. Interestingly, there were confined masses of red blood cells in the epidermal layer as well as both in and on the horny layer. This is a feature of transepidermal elimination. This transepidermal elimination appeared to be triggered or enhanced by the concomitant contact dermatitis due to topical antibiotics. To the best of our knowledge, this is the first report of angiokeratoma in which the angiokeratoma itself reduced in size through transepidermal elimination, possibly caused by contact dermatitis.

Angiokeratoma↗
PubMed1992

The Koebner phenomenon in eruptive xanthoma.

A 49-year-old woman with Type V hyperlipidemia had yellow papules smaller than 3 mm in diameter with red haloes on her elbows, shoulder, buttocks, and hands. Two linear lesions composed of papules arising at the sites of skin previously injured by a cat scratch were observed. Histopathological examination of these papules revealed the presence of many foam cells in the dermis which stained positively with oil red O stain. A survey of the literature found only 5 cases of the Koebner phenomenon in xanthoma.

Animals↗
PubMed1992

Eruptive pruritic papular porokeratosis.

Three cases of an unusual variant of porokeratosis (Mibelli) were described. Patients with disseminated superficial porokeratosis for some years suddenly developed intensively pruritic erythematous papules. Skin biopsies revealed that these papules contained cornoid lamellae on their tops. Pruritic papules subsided in several months, leaving slightly hyperkeratotic brown annular lesions which were shown to contain typical cornoid lamellae histopathologically. This type of porokeratosis has not been reported in the literature.

Acute Disease↗
PubMed1991

An improved ELISA system for the measurement of IgG antibodies against pertussis toxin (PT) and filamentous hemagglutinin (FHA) in human sera.

We have developed a modified assay method for the measurement of antibodies against PT and FHA. Polystyrene balls coated with purified PT and FHA were incubated with standard or test sera, washed, incubated with goat anti-human IgG F(ab')2 conjugated with horseradish peroxidase and then washed again. Peroxidase activity was then measured by color development using o-phenylenediamine. The anti-PT and anti-FHA IgG titers were determined using calibration curves. The assay standard curves for anti-PT and anti-FHA were both linear from 1 to 100 ELISA units per milliliter (EU ml-1), and the assay sensitivity was calculated to be 1 EU ml-1 in both cases. Intra- and inter-assay CVs were both less than 10%. Inter-laboratory assay CVs calculated from the results from four different facilities were 3.3-34.6% (average 14.5%) and 2.1-30.3% (average 13.6%) for anti-PT and anti-FHA IgG, respectively, and the correlation coefficient between the Chinese hamster ovary (CHO) cell assay and the anti-PT PS-ball ELISA assay was 0.959. Using this assay method we obtained in a highly sensitive and reproducible measurement of IgG antibodies against PT and FHA in human sera. This assay should be especially useful for the determination of low concentrations of these antibodies.

Adhesins, Bacterial↗
PubMed1990

Tumor growth-inhibitory glycoprotein secreted from the mouse brain at terminal stage of the ontogeny: molecular homogeneity and requirement of the retained protein conformation for exhibition of the cytotoxic action.

The mouse brain at the neonatal stage but not at the adult or fetal stage, secretes a protein which inhibits growth and DNA synthesis of malignant cells preferentially over those of normal cells, and so is termed neonatal brain-derived carcinostatic factor (NBCF). In the present study, NBCF was prepared from conditioned medium cultured from neonatal brain, and was obtained by HPLC as a homogeneous protein (62 kDa, pI 9.1); physico-chemical and biological properties of NBCF differ from those of cerebral proteins known. A 1,2-cis-diol affinity column retained NBCF, which was thereafter eluted with D-sorbitol; NBCF treated with neuraminidase lost part of activity without emergence of new N-terminal amino acids, suggesting glycan moieties required for the activity exhibition. This is supported by repression of NBCF secretion by tunicamycin of doses as low as is not cytotoxic. NBCF did not hydrolyze target proteins; cytotoxic action of NBCF was not counteracted by a diversity of proteinase inhibitors. An ether extract of NBCF was not cytotoxic, whereas the ether-insoluble residuum retained part of the initial activity. NBCF was inactivated with immobilized trypsin or with dithiothreitol combined with guanidine more markedly than with either agent. Thus cytotoxicity exhibition of NBCF, mediated through actions other than proteolysis, is attributed to the proteinic principle but not to protein-bound lipophilic ligands, and requires retention of the protein conformation and intramolecularly buried SS bonds.

Animals↗