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Biomedical subjects

K Okazaki

Publications and source records attributed to K Okazaki.

At least 379 records · Page 21Linked to original sources
PubMed1987

Bovine herpesvirus type 1 gp87 mediates both attachment of virions to susceptible cells and hemagglutination.

The 87,000-dalton glycoprotein (gp87) of bovine herpesvirus type 1 (BHV-1) was found to selectively attach to susceptible cells. The attachment of gp87 to the cells was markedly decreased by the prior adsorption of intact virions. Anti-gp87 (site Ia) monoclonal antibody, which inhibited BHV-1 adsorption to the cells and neutralized the virus without complement [Okazaki et al., Virology 250: 260-264], was effective in inhibiting the adsorption of gp87. Only the same antibody was able to inhibit the hemagglutination activity of BHV-1. Other monoclonal antibodies to the glycoproteins of BHV-1, including antibodies directed to sites Ib and Ic on gp87, were ineffective in inhibiting either virus adsorption or hemagglutination. The results of this study indicate that site Ia of gp87 molecule is the critical site of virus attachment for initiation of infection as well as the hemagglutination of BHV-1.

Animals↗
PubMed1987

An attempt to assay the state of determination by using transfected genes as probes in transdifferentiation of neural retina into lens.

Hybrid genes coding for chloramphenicol acetyltransferase (CAT) with a non-specific retroviral, lens-specific delta-crystallin or lens-specific alpha-crystallin promoters were constructed to transfect the transdifferentiating (lentoidogenic) and non-transdifferentiating (non-lentoidogenic) cultures of chicken embryonic neural retina for assaying the state of determination towards lens differentiation. The expression occurred only when CAT genes with lens-specific promoters were transfected to the cultures maintained in the conditions permissive to lentoidogenesis. The expression of these exogenous, lens-specific CAT genes began at stages of culturing that were earlier than the expression of endogenous crystallin. Presumably, there are two steps in the transdifferentiation of neural retina into lens; acquisition of capacity to express crystallin genes and derepression of the endogenous crystallin genes.

Animals↗
PubMed1987

Typing of herpes simplex virus types 1 and 2 by immunoblotting analysis using polyclonal antisera to herpes simplex virus glycoproteins.

Herpes simplex virus (HSV) isolates were differentiated by immunoblotting analysis using a mixture of polyclonal antisera directed against HSV type 1 (HSV-1) and HSV type 2 (HSV-2) glycoprotein fractions (gB/gC of HSV-1 and gC/gE/84-kDa protein of HSV-2), since the mixed antisera recognized viral polypeptides with different molecular weights in HSV-1- and HSV-2-infected cells. Results of typing by immunoblotting analysis were consistent with those obtained by restriction endonuclease analysis of DNAs extracted from 10 HSV isolates. These results suggest that the immunoblotting technique will be applicable to reliable typing of HSV isolates using polyclonal antisera showing the difference in reaction patterns between HSV-1- and HSV-2-infected cells.

Animals↗
PubMed1987

Peroxisomal acyl-coenzyme A oxidase multigene family of the yeast Candida tropicalis; nucleotide sequence of a third gene and its protein product.

We have determined the complete nucleotide sequence of gene POX2, which encodes one of the major peroxisomal polypeptides (PXPs) of Candida tropicalis. POX2 is linked to gene POX4, which codes for a subunit (PXP-4) of long-chain acyl-CoA oxidase. Southern blot analysis revealed that POX2 had a significant homology to POX4, and also to gene POX5 which encodes a subunit (PXP-5) of the isozyme of acyl-CoA oxidase. PXP-2, the protein product of POX2, was co-purified with PXP-4 from the isolated peroxisomes. PXP-2 itself was a flavoprotein and likely to form an equimolar complex with PXP-4, although its enzymatic activity was uncertain. POX2 corresponds to a single open reading frame of 724 amino acids and has no introns. The N-terminal sequence and the calculated Mr of the deduced polypeptide were consistent with those of isolated PXP-2. The primary structure was highly homologous to those of PXP-4 and PXP-5 in respect of the amino acid sequence and the hydropathy profile. We conclude that POX2 is a third gene of the peroxisomal acyl-COA oxidase multigene family.

Acyl-CoA Oxidase↗
PubMed1987

Specificity of rat liver cathepsin D.

The specificity of highly purified rat liver cathepsin D was investigated by analyzing the digests of denatured proteins. At the P1 site, cathepsin D prefers hydrophobic residues except Ile and Val, that are branched at the beta-carbon. Strong and weak hydrophobicities are required at P1' and P2 sites, respectively. A lower protency for beta-turn formation is essential for the sequence around the P1 site.

Amino Acid Sequence↗
PubMed1987

Anatomic variants of choledochocele and manometric measurements of pressure in the cele and the orifice zone.

We report five cases of choledochocele and propose five anatomic variants (types A-E) on the basis of endoscopic retrograde cholangiography findings. To clarify pathophysiology of the disease manometric studies were performed in the three cases. As a result, the orifice of the cele was proved to act like a sphincter. Two of them with normal motility of the orifice showed normal pressures in the cele. However, one case with spastic motility of the orifice showed high pressure in the cele. All five cases had chronic pancreatitis. In a case (type E) without communication between the cele and the pancreatic duct, the cause of pancreatitis seemed to be increased pancreatic ductal pressure due to disturbed motility of an inflamed pancreatic sphincter. In the other four cases with communication between the cele and the pancreatic duct, the cause of pancreatitis may be a reflux of bile juice into the pancreatic duct. Manometric study seems to be useful in clarifying the pathophysiology of choledochocele.

Aged↗
PubMed1986

Mechanisms of neutralization by monoclonal antibodies to different antigenic sites on the bovine herpesvirus type 1 glycoproteins.

Monoclonal antibodies directed to different antigenic sites on bovine herpesvirus type 1 (BHV-1) glycoproteins were used to study the mechanisms of neutralization of the virus. Three nonoverlapping neutralizing antigenic sites, designated Ia, Ib, and Ic, were defined on gp87. Antibodies to site Ia which mediated viral neutralization without complement were effective on inhibition of virus adsorption. Antibodies to a single neutralization site on gp71, designated IIa, were able to neutralize the virus without complement even when they were incubated with the virus which had already adsorbed onto the cells. Antibodies directed against gp117 and antibodies against sites Ib and Ic on gp87 required complement for virus neutralization.

Antibodies, Monoclonal↗
PubMed1986

Spontaneous rupture of the spleen and liver in amyloidosis--a case report and review of the literature.

A 52 year-old woman with systemic amyloidosis complicated with multiple myeloma died suddenly of intraperitoneal hemorrhage due to spontaneous rupture of the spleen and liver. Autopsy revealed multiple myeloma involving the bone marrow and diffuse amyloidosis involving the liver, spleen, kidneys, heart, bone marrow, lymph nodes, lungs, gastrointestinal tract, thyroid, skin and adrenal glands. The splenic red pulp and the hepatic parenchyma were replaced by masses of amyloid. Amyloid deposits were also numerous in the walls of blood vessels and linearly in the intracapsular regions of both the liver and spleen. This is the eighth case of spontaneous rupture of the spleen and the second case of spontaneous rupture of the liver in association with systemic amyloidosis.

Amyloidosis↗
PubMed1986

Endoscopic measurement of papillary sphincter zone and pancreatic main ductal pressure in patients with chronic pancreatitis.

To determine the significance of manometric pressure of the pancreatic duct, we used a microtransducer inserted through a duodenoscope to measure pressures in the papillary sphincter zone and pancreatic main duct in 20 control subjects and 20 patients with chronic pancreatitis, and recorded the effect of exogenous glucagon or secretin. There was no significant difference between control subjects and patients with chronic pancreatitis without papillitis in the motility of the sphincter of Oddi. The pancreatic main ductal pressure was significantly higher in the patients with chronic pancreatitis (54.5 +/- 29.9 mmHg) than in the control subjects (16.2 +/- 8.7 mmHg). The viscosity of pure pancreatic juice of patients with chronic pancreatitis [5.8 centipoise (cp)] in the basal secretory state was significantly higher than that of the control subjects (1.61 cp). These data lead to the hypothesis that increased pancreatic ductal pressure in patients with chronic pancreatitis without papillitis is due not to papillary dysfunction, but to increased viscosity or other unknown factors.

Ampulla of Vater↗
PubMed1986

Two acyl-coenzyme A oxidases in peroxisomes of the yeast Candida tropicalis: primary structures deduced from genomic DNA sequence.

We report the complete nucleotide sequence of two genes encoding major peroxisomal polypeptides (PXPs) of Candida tropicalis. One, POX4, encodes PXP-4, which is the most abundant polypeptide in cells grown on oleic acid, and the other, POX5, is the gene for PXP-5. Each of the two polypeptides was found to be the subunit of a distinct long-chain acyl-coenzyme A oxidase: acyl-CoA oxidase II (PXP-4) or acyl-CoA oxidase I (PXP-5). Both the genes had no intron and gave a single open reading frame. The NH2-terminal sequences, except the initiator methionine, and the calculated molecular weights of the deduced polypeptides were consistent with those of the respective PXPs. Well-conserved sequences of 12 and 16 hydrophobic amino acids were present in the middle of the polypeptide, instead of at the NH2 terminus, and may be internal signal sequences for the peroxisomal location of PXPs. Although the two polypeptides were significantly homologous throughout their sequences, the local homologies in two regions out of five were markedly diverged from the average (63%); the homology in the second region was 93%, whereas that in the fourth one was only 24%. The implications of this finding are discussed in respect to the multiplicity of peroxisomal enzymes and the presence of multifunctional proteins in peroxisomes.

Acyl Coenzyme A↗