Search PubMed⌕ Search

Biomedical subjects

M Shoji

Publications and source records attributed to M Shoji.

At least 163 records · Page 9Linked to original sources

Production of recombinant human monoclonal antibody using ras-amplified BHK-21 cells in a protein-free medium.

A ras oncogene-amplified recombinant BHK-21 cell line (ras-rBHK-IgG) has been established, and was shown to hyperproduce the recombinant IgG chimeric human monoclonal antibody (hMAb) AE6F4, which recognizes lung cancer cells. We found that the ras-rBHK-IgG cell could be easily cultured in a protein-free ERDF medium supplemented with iron(III) nitrate, hydroxyethyliminodiacetic acid, and non-protein synthetic attachment factor as well as in a serum-free ERDF medium supplemented with insulin, transferrin, ethanolamine, and sodium selenite. The productivity of recombinant hMAb from the cells cultured in dishes at high cell densities was higher in protein-free medium than in serum-containing medium. True high density culture of the ras-rBHK-IgG cells was done in protein-free medium using the Tecnomouse, which is a novel hollow fiber bioreactor system. After culture for 30 days in protein-free culture, a total amount of about 14 mg of the recombinant hMAb AE6F4 was obtained, and was shown to be reactive against lung cancer cells in tissues.

Animals↗

Cortical laminar necrosis and central pontine myelinolysis in a patient with Sheehan syndrome and severe hyponatremia.

Hypoxic encephalopathy and osmotic demyelination are independent clinical entities. We describe a rare case with these two complications as demonstrated by magnetic resonance imaging (MRI). A 58-year-old woman had adrenal crises twice a decade due to Sheehan syndrome. At the second crisis, hyponatremia was remarkable with consciousness disturbance which was rapidly corrected by intravenous administration of glucocorticoid and hypertonic saline. The maneuver improved consciousness disturbance, but resulted in hypokalemic ventricular fibrillation with circulatory failure. After the normalization of the circulation, however, her consciousness level deteriorated again. Repeated brain MRI revealed acute and chronic phases of cortical laminar necrosis and central pontine myelinolysis.

Brain↗

Further studies on the urinary metabolites of 2,4-dinitrotoluene and 2,6-dinitrotoluene in the male Wistar rat.

1. Conjugates of 2,4-dinitrobenzyl alcohol (2,4-DNB) and 2,6-dinitrobenzyl alcohol (2,6-DNB), which were major urinary metabolites of the male Wistar rat dosed orally with 2,4-dinitrotoluene (2,4-DNT) or 2,6-dinitrotoluene (2,6-DNT), were examined by hplc using potassium 2,4-dinitrobenzyl glucuronide (2,4-DNB-G), potassium 2,6-dinitrobenzyl glucuronide (2,6-DNB-G), pyridinium 2,4-dinitrobenzyl sulphate (2,4-DNB-S), and pyridinium 2,6-dinitrobenzyl sulphate (2,6-DNB-S) as authentic compounds. Other metabolites were also examined by hplc. 2. Conjugates detected from urine following administration of 2,4-DNT and 2,6-DNT were 2,4-DNB-G and 2,6-DNB-G, which accounted for about 10.7 and 17.4% of the administered dose respectively. No peaks corresponding to pyridinium 2,4-DNB-S and pyridinium 2,6-DNB-S were detected in urine samples. 3. 2-Amino-4-nitrobenzoic acid (0.71%), 4-amino-2-nitrobenzoic acid (0.52%) and 4-acetylamino-2-nitrobenzoic acid (3.9%), in addition to known metabolites 4-amino-2-nitrotoluene (0.04%), 2,4-DNB (0.25%), 2,4-dinitrobenzoic acid (6.9%) and 4-acetylamino-2-aminobenzoic acid (3.4%), were detected in ether extracts of urine of rat given 2,4-DNT. 2,6-Dinitrobenzoic acid (0.17%) and two known metabolites, 2-amino-6-nitrotoluene (0.44%) and 2,6-DNB (0.53%), were detected in ether extracts of urine of rat given 2,6-DNT.

Animals↗

Lung cancer-reacting human recombinant antibody AE6F4: potential usefulness in the sputum cytodiagnosis.

Human monoclonal antibody (hMAb) AE6F4 has been shown to be potentially useful for immunocytological detection of lung cancer cells in sputum. By recombinant DNA technology, IgM type hMAb AE6F4 was switched to lgG. The IgG mimic recombinant AE6F4 antibody expression plasmid was assembled using the antibody heavy chain gene, which ligated the gene encoding VH and CH1(mu) domains of hMAb AE6F4 heavy chain to the gene encoding CH2(gamma 1) and CH3(gamma 1) domains of human IgG heavy chain, and the antibody light chain gene of hMAb AE6F4. The recombinant antibody expressed by baby hamster kidney (BHK)-21 cells showed molecular size equivalence to IgG, and consisted of human mu-gamma hybrid heavy and kappa light chains. The immunological specificity of the recombinant antibody was the same as that of hMAb AE6F4 by immunoblotting analysis to the 14-3-3 protein, the putative antigen of hMAb AE6F4, and by immunohistochemical and immunocytological analyses using tissue sections and sputa of lung cancer patients. The transfected BHK-21 cells produced the recombinant antibody persistently and the productivity was greater than 20 times that by human-human hybridoma producing hMAb AE6F4.

14-3-3 Proteins↗

Amyloid beta-protein ending at Thr43 is a minor component of some diffuse plaques in the Alzheimer's disease brain, but is not found in cerebrovascular amyloid.

The distribution of amyloid beta-protein ending at 40 (A beta 40), 42 (A beta 42), and 43 (A beta 43) were immunocytochemically examined in Alzheimer's brains. A large number of diffuse plaques were stained with A beta 42 antibody (S42), but some were weakly labeled with A beta 43 antibody (S43). Immature and mature plaques were labeled with A beta 40 antibody (S40), S42, and S43. Thus, A beta 42 is the major component of diffuse plaques, the initial phase of plaque formation, and A beta 43 is present as a minor component. Only A beta 40 is present in cerebrovascular amyloid.

Aged↗

Selective inhibition of DNA polymerase-alpha family with chemically synthesized derivatives of PHYLPA, a unique Physarum lysophosphatidic acid.

PHYLPA, a unique Physarum lysophosphatidic acid (LPA), showed selective inhibition of a family of DNA polymerase alpha, including DNA polymerases alpha, delta and epsilon; but no inhibition of DNA polymerase beta or gamma was observed. To reveal the molecular mechanism of inhibition of DNA polymerases by PHYLPA, four stereoisomers and some other derivatives were synthesized and their effects on DNA polymerases were studied. Among eight derivatives synthesized, PHYLPA-1 (the natural PHYLPA; sodium 1-O-[(9'S,10'R)-9',10'-methanohexadecanoyl]-sn-glycerol 2,3-cyclic phosphate) and PHYLPA-2 (sodium 3-O-[9'S,10'R)-9',10'-methanohexadecanoyl]-sn-glycerol 1,2-cyclic phosphate) were strong and specific inhibitors of a family of DNA polymerase alpha. But their stereoisomers PHYLPA-3 (sodium 1-O-[9'R,10'S)-9',10'-methanohexadecanoyl]-sn-glycerol 2,3-cyclic phosphate) and PHYLPA-4 (sodium 3-O-[9'R,10'S)-9',10'-methanohexadecanoyl-sn-glycerol 1,2 cyclic phosphate) were weak inhibitors, showing the critical importance of stereochemistry of a cyclopropane-containing fatty acid for the inhibitory activity. Some derivatives having no cyclopropane-containing fatty acids--palmitoyl-, oleoyl-, and palmitoleoyl-PHYLPA--showed inhibition to some extent; but 1-palmytoyl and 1-oleoyl lysophosphatidic acid, which has no cyclic phosphate, did not show an apparent inhibitor activity on DNA polymerases. Hence, the extent of the inhibition apparently depends on the stereochemistry of both the fatty acid moiety and the cyclic phosphate.

Animals↗

Modified amyloid beta protein ending at 42 or 40 with different solubility accumulates in the brain of Alzheimer's disease.

Serial extraction study of Alzheimer's disease (AD) and control brains revealed 4, 3.7 and 3 kD amyloid beta protein (A beta) species accumulated in AD brains. In the fractions extracted with TBS, 10% SDS and formic acid, considerable amounts of A beta species were recovered in SDS fractions besides TBS and formic acid fractions. Immunoblotting with several site-specific antibodies confirmed not only the presence of 4 kD A beta starting at the first amino acid of A beta but also 2 smaller A beta species with modification of their amino-termini in the highly resolutional Tris/Tricine gel system. A beta solubility using these solvents was associated with both modification of the amino-terminus and length of carboxyl-terminus of A beta. Especially, a large amount of modified A beta was found to be accumulated as forms with different solubility in AD brains.

Aged↗

Tau in cerebrospinal fluids: establishment of the sandwich ELISA with antibody specific to the repeat sequence in tau.

Clinical diagnosis for Alzheimer's disease (AD) is provided by the criteria of DSMIV and clinical progress in addition to imaging analysis with MRI after negative screening. The final exclusive diagnosis is confirmed by the neuropathological findings of neurofibrillary tangles and senile plaques in autopsy brains. We developed a new ELISA system to measure the amount of tau in cerebrospinal fluids (CSF) using phosphorylation-independent and sequence-specific antibodies. The present ELISA was sensitive enough to detect tau in CSF of normal subjects. The amount of tau was significantly elevated in CSF of AD subjects compared with those of normal subjects and subjects with dementia of cerebrovascular disease, suggesting that tau in CSF reflects the massive and continuous neuronal cell death in the AD brain. In conclusion, we established an ELISA system which enabled us to detect tau in CSF and demonstrated that tau was significantly and specifically elevated in CSF of AD subjects. This assay system can provide us with a potent diagnostic tool for clinical AD.

Alzheimer Disease↗

Molecular cloning of the 31 kDa cytosolic phospholipase A2, as an antigen recognized by the lung cancer-specific human monoclonal antibody, AE6F4.

The human monoclonal antibody AE6F4 specifically reacts with human lung cancer tissues but does not with normal tissues. This monoclonal antibody recognizes a cytosolic 31 kDa antigen in the cancer cells. In a previous study, we elucidated that the 31 kDa antigen belonged to a family of proteins collectively designated as 14-3-3 proteins, which were known as protein kinase-dependent activators of tyrosine/trytophan hydroxylases, or protein kinase C inhibitor proteins. Here we report molecular cloning of the 31 kDa antigen from the human lung adenocarcinoma cell line, A549. Sequencing analysis indicates that the cloned cDNA is identical to that of previously reported human placental cytosolic phospholipase A2 (cPLA2), which is also a member of the 14-3-3 protein family. Western analysis demonstrated that a 31 kDa recombinant cPLA2 expressed in monkey COS cells was recognized by the AE6F4 monoclonal antibody. Binding of the monoclonal antibody to the recombinant cPLA2 was abolished when treated with sodium periodate, suggesting that not only are carbohydrate chains associated with the cPLA2, but they also play a crucial role in antigen recognition by the monoclonal antibody.

14-3-3 Proteins↗

Elevation of ratio of urinary N-acetylneuraminlactose to free sialic acid in some advanced cancer patients.

We estimated the levels of free sialic acid and sialylated oligosaccharides excreted in the urine of normal donors (n = 10) and patients with gastric cancer (n = 6) and colorectal cancer (n = 4). The total sialic acid level in cancer patients was similar to that in normal donors. However, the ratios of glycosidically bound sialic acids to free sialic acid were higher in some advanced cancer patients than in the normal donors. A major component of sialylated oligosaccharides was N-acetylneuraminyl alpha (2-->3) lactose. The elevation of the urinary ratio of this sialylated oligosaccharide to free sialic acid observed in some advanced cancer patients in this study may reflect the elevation of sialyltransferase activity in tumor tissues.

Adult↗

Megakaryocytic differentiation of a leukemic cell line, MC3, by phorbol ester: induction of glycoprotein IIb/IIIa and effects on expression of IL-6, IL-6 receptor, mpl and GATA genes.

We investigated megakaryocytic differentiation in a newly-established Ph1-positive leukemic cell line, MC3, which showed tri-lineage immunophenotypes (myeloid antigens2+, CD19(1+) and CD41a1+) and was positive for CD34 and CD38. TPA induced MC3 cells to differentiate to an early stage of megakaryocyte lineage exhibiting an increase in the expression of platelet glycoproteins (GP) IIb/IIIa (CD41a), and an increase in cell size and nuclear ploidy. TPA treatment also enhanced the expression of GPIIb mRNA, and induced the expression of interleukin-6 (IL-6) and its receptor mRNAs, while it did not induce transcripts of the genes IL-11 and mpl ligand, and further decreased the transcript of the mpl gene. Consistent with these findings, MC3 cells treated with TPA showed an increased expression of GATA-1, but not GATA-3 transcripts, whereas those without TPA treatment expressed only the GATA-2 transcript. These results provide an insight into the study for the regulatory mechanism of megakaryocytopoiesis and leukemic cell differentiation.

Antigens, CD↗

Variable clinical symptoms in familial amyotrophic lateral sclerosis with a novel point mutation in the Cu/Zn superoxide dismutase gene.

We report a novel missense point mutation in exon 4 of the Cu/Zn superoxide dismutase (SOD) gene of affected members of a Japanese kindred segregating familial amyotrophic lateral sclerosis (FALS) through at least three successive generations. The mutation, which is predicted to cause the replacement of isoleucine at codon 104 by phenylalanine (I104F), is associated with a significant reduction in Cu/Zn SOD enzyme activity but results in a highly variable clinical phenotype. Age at onset varied from 6 to 55; the initial symptoms occurred in either the lower or upper extremities in different family members. The duration of the disease varied from 3 to 38 years. Two subjects, aged 59 and 34, remained asymptomatic until their death from other causes, although their offspring carrying the same mutation have already developed clinical evidence of the disease. These results suggest that FALS from this novel I104F mutation shows considerable clinical variation.

Adult↗

Effects of V1- and V2-vasopressin (AVP) antagonists on the pressor, AVP and atrial natriuretic peptide responses to a hypertonic saline infusion in conscious anephric rats.

To examine the role of vasopressin (AVP) receptors in the regulation of the hemodynamics and release of atrial natriuretic peptide (ANP), and the participation of renal nerve inputs in the osmotic AVP release, hypertonic saline (HS) was infused into conscious, bilaterally nephrectomized rats with non-peptide, selective antagonists for the V1-receptor or V2-receptor of AVP. In the control group, HS alone increased mean arterial pressure, plasma ANP and AVP, plasma volume and plasma osmolality, and decreased the heart rate. In the V1-receptor antagonist group, an increase in the mean arterial pressure and a decrease in heart rate were completely abolished and an increase in plasma ANP was attenuated. In the V2-receptor antagonist group, increases in mean arterial pressure and plasma ANP and a decrease in heart rate were attenuated. However, the ratio of the changes in heart rate to the changes in mean arterial pressure in the V2-receptor antagonist group is significantly higher than that in the control group. In both experimental groups, increases in plasma AVP, plasma volume and plasma osmolality were not different from those in the control group. These results suggest that a HS-induced increase in mean arterial pressure is mediated by the pressor effect of AVP, mainly through V1-receptors, and that the depressor effect of AVP through V2-receptors may not influence tonically HS-induced hypertension. Moreover, HS-induced increase in plasma ANP is mediated mainly by increases in plasma volume and blood pressure, but may not be affected by a direct action of AVP to the heart. Renal afferent nerve inputs may not have effects on the regulation of osmotic AVP release.

Animals↗

Chlorpropamide-induced ADH release, hyponatremia and central pontine myelinolysis in diabetes mellitus.

Chlorpropamide (CPM) has been reported to produce impaired water excretion due to the enhancement of renal vasopressin (ADH) action and/or due to centrally enhanced ADH release, but it is still unknown whether CPM gives rise to ADH release with a subsequent hyponatremia in diabetes mellitus (DM), which, in turn, causes an impairment of the central nervous system. In 3 patients with DM, who developed hyponatremia during the treatment with CPM, an acute water load (WL) was carried out in the presence and absence of the drug, and plasma ADH was determined with plasma and urine osmolalities. Moreover, in 2 cases, MRI scans of the brain were taken. In all the patients, acute WL tests failed to suppress completely ADH release in response to changes in plasma osmolality in the presence of CPM, which, in turn, resulted in the impaired water excretion. In the absence of CPM, an acute WL normally suppressed plasma ADH leading to the diuresis. MRI scans illustrated the presence of central pontine myelinolysis. It is likely that CPM might stimulate ADH release in DM with a subsequent hyponatremia and brain damages.

Aged↗

Changes in plasma vasopressin levels and cardiovascular function due to postural changes in diabetic neuropathy.

Decreases in blood pressure are well known to increase the release of vasopressin. Studies were carried out to investigate whether vasopressin responses to postural changes in blood pressure are maintained in diabetic patients with orthostatic hypotension [DM-OH(+)] as well as non-diabetic patients with orthostatic hypotension [nonDM-OH(+)] and these responses were compared with those observed in normal subjects and diabetic patients without orthostatic hypotension [DM-OH(-)]. After 30 min in the supine position, the upright posture for 40 min was maintained and then the supine for 10 min. Blood pressure and heart rate (HR) were measured every 5 min and plasma vasopressin levels (plasma AVP) were determined every 10 min. In normal subjects and DM-OH(-), mean arterial blood pressure (MABP) did not change, but HR increased significantly by the upright position. Plasma AVP did not change in these groups. On the other hand, in DM-OH(+) MABP fell abruptly and remained to decrease during the upright posture. The HR responses in this group, however, were similar to those in normal control and DM-OH(-). Plasma AVP in DM-OH(+) significantly increased only at 30 min during upright. These increases were significantly greater than those in normal and DM-OH(-). There were significant correlation in changes in MABP (delta MAP) and plasma AVP (delta AVP) in DM-OH(+) (delta AVP = -0.13 MABP + 1.5, r = -0.32, p < 0.01). Relationship between delta MABP and delta AVP in nonDM-OH(+) was similar to that in DM-OH(+). It is concluded that AVP responses to orthostatic hypotension in diabetic and non-diabetic neuropathies were attenuated, but heart rate responses in these patients ware well reserved.

Adult↗

Role of atrial natriuretic peptide in interleukin 1 beta-induced natriuresis in conscious rats.

To assess whether atrial natriuretic peptide (ANP) plays a role in the natriuresis induced by interleukin 1 beta (IL-1 beta), the following experiments were carried out. Experiment (Ex) I: IL-1 beta (7.5 micrograms/kg BW) was given intravenously (i.v.) in conscious hydrated rats (n = 6). Plasma ANP, vasopressin (AVP) osmolality (Posm), Na and K, urine Na (UNa V) and K excretion (UK V), osmolality and flow (UF), and mean arterial blood pressure (MABP) and heart rate were simultaneously determined. In the control group (n = 6), the drug was omitted, and the same protocols were carried out. Ex II: Three mg/kg BW of the specific ANP antagonist, HS-142-1 (HS), was administered i.v. and then, IL-1 beta (7.5 micrograms/kg BW) was given i.v. (n = 6). In the HS alone group (n = 6), IL-1 beta was omitted. The experimental protocols were the same as those in Ex I. IL-1 beta increased significantly plasma ANP and AVP and UNa V, but not UF, accompanied by decreases in Posm and UKV and increases in MABP (ExI). HS inhibited the natriuresis mediated by IL-1 beta, despite increases in plasma ANP and had no influence on plasma AVP and MABP. In the control (ExI) and HS alone (ExII) groups, these parameters did not change, except for decreases in Posm in both groups and increased plasma ANP in the latter. These results suggest that plasma ANP may play an essential role in the IL-1 beta-mediated natriuresis.

Animals↗