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S Oka

Publications and source records attributed to S Oka.

At least 199 records · Page 11Linked to original sources

Maternal Meal Ingestion Does Not Affect Amniotic Fluid Index during Short-period Observation in Normal Pregnancy

>Objective: To determine whether maternal meal ingestion affects amniotic fluid index (AFI) over a short period after maternal meal ingestion in normal growth fetuses with normal amniotic fluid volume in uncomplicated late pregnancies.Methods: Twenty-five women with an appropriate-for-gestational-age fetus with normal AFI were included in a simple crossover, blinded study during late pregnancy. After an overnight fast, two different maternal meal states were prepared. On day A, the subjects had a standard 600-kcal breakfast at 8 a.m. On day B, the fasting state was maintained until 10 a.m. Both states were randomly assigned to each woman within 3 days. On both days, the AFI was measured at 7 a.m. (the fasting state) and at 10 a.m. (the fed state on day A and the continuous fasting state on day B). A change in AFI between 7 and 10 a.m. was compared between the days by paired t test.Results: The mean gestational age (mean +/- SD) was 37.5 +/- 1.5 weeks on day A and 37.4 +/- 1.6 weeks on day B. The change in AFI between 7 and 10 a.m. was 1.1 +/- 3.0 cm on day A (with breakfast) and 2.1 +/- 2.6 cm on day B (keeping fast). These changes were not different between the days (P = 0.19).Conclusions: Maternal meal ingestion had no apparent acute effect on AFI in normal growth fetuses with normal amniotic fluid volume.

Journal Article↗

Optimal conditions of immune complex transfer enzyme immunoassays for antibody IgGs to HIV-1 using recombinant p17, p24, and reverse transcriptase as antigens.

The immune complex transfer enzyme immunoassays for antibody IgGs to p17, p24, and reverse transcriptase (RT) of HIV-1 were tested under various conditions. Antibody IgGs to HIV-1 were reacted for up to 20 hr with 2,4-dinitrophenyl-bovine serum albumin-recombinant HIV-1 protein conjugates and recombinant HIV-1 protein-beta-D-galactosidase conjugates, and the immune complexes formed, comprising the three components, were trapped onto polystyrene beads coated with (anti-2,4-dinitrophenyl group) IgG by incubation at 4-30 degrees C for up to 2 hr with shaking and were transferred onto polystyrene beads coated with (antihuman IgG gamma-chain) IgG in the presence of excess of epsilon N-2,4-dinitrophenyl-L-lysine by incubation at 4-30 degrees C for up to 2 hr with shaking. When serum randomly collected from an HIV-1 seropositive subject and serum included in an Western blot kit were tested, the formation of the immune complex was almost completed within 1 hr for antibody IgG to p17, within 1-2 hr for antibody IgG to p24 and within 4 hr for antibody IgG to RT. Even for antibody IgG to p17, however, the immune complex continued to be formed for at least 2 hr, when serum samples at early stages of HIV-1 infection were tested. Trapping and transferring of the immune complexes were faster at higher temperatures and were almost completed within 0.5-1.5 hr, although the amount of the immune complexes trapped and transferred at 25 and/or 30 degrees C increased for 0.5-1 hr, but subsequently tended to decline. When the formation, trapping, and transferring of the immune complexes were performed for 0.5, 1, and 1 hr, respectively, with shaking followed by 1 hr assay of bound beta-D-galactosidase activity, the sensitivities for antibody IgGs to p17, p24, and RT using 10 microliters of serum samples were similar to or significantly higher than those of the corresponding previous immune complex transfer enzyme immunoassays using 10 microliters of serum samples, in which the formation, trapping, and transferring of the immune complexes were performed for 3, 16, and 3 hr, respectively, without shaking, followed by 2.5 hr assay of bound beta-D-galactosidase activity, and the sensitivities for antibody IgGs to p17, p24, and RT using 100 microliters of serum samples were 21-22-fold, 5.5-6.3-fold, and 5.3-6.0-fold, respectively, higher. When each period of time for the formation, trapping, and transferring of the immune complexes was prolonged to up to 4 hr, the sensitivities for antibody IgGs to p17, p24, and RT using 100 microliters of serum samples were improved 88-93-fold, 15-17 fold and 20-24-fold, respectively, as compared with those of the previous ones.

Antigen-Antibody Complex↗

Ultrasensitive and rapid enzyme immunoassay (thin aqueous layer immune complex transfer enzyme immunoassay) for antibody IgG to HIV-1 p17 antigen.

The immune complex transfer enzyme immunoassay for antibody IgG to HIV-1 p17 antigen was performed in two different ways (the present immunoassays I and II) within shorter periods of time than previously reported. In the present (simultaneous) immunoassay I, antibody IgG to HIV-1 p17 antigen in 10 microL of serum samples was incubated simultaneously with 2,4-dinitrophenyl-maltose binding protein-recombinant p17(rp17) fusion protein and rp17-beta-D-galactosidase conjugate in a total volume of 22 microL for 10 min to form the immune complex comprising the three components. The reaction mixture was incubated with a polystyrene bead of 6.35 mm in diameter coated with affinity-purified (anti-2,4-dinitrophenyl group) IgG for 5 min in a styrol test tube (13.3 x 54 mm and 2.1 g) to trap the immune complex. After washing, the polystyrene bead was incubated with 30 microL of epsilonN-2,4-dinitrophenyl-L-lysine solution in a polystyrene tube (12 x 75 mm) coated with affinity-purified (antihuman IgG gamma-chain) IgG for 10 min to transfer the immune complex. In the present (sequential) immunoassay 11, a polystyrene bead of 6.35 mm in diameter coated successively with affinity-purified (anti-2,4-dinitrophenyl group) IgG and 2,4-dinitrophenyl-maltose binding protein-rp17 fusion protein was incubated in a styrol test tube (13.3 x 54 mm and 2.1 g) sequentially with antibody IgG to HIV-1 p17 antigen in 10 microL of serum samples in a total volume of 16 microL for 5 min and subsequently with rp17-beta-D-galactosidase conjugate in a volume of 10 microL for 5 and 10 min. The immune complex formed on the polystyrene bead was transferred to a polystyrene tube coated with affinity-purified (antihuman IgG gamma-chain) IgG for 5 and 10 min in the same way as in the present immunoassay I. During the incubations, the styrol test tubes containing the polystyrene beads and reaction mixtures were shaken, and the polystyrene test tubes were rotated with shaking, so that the polystyrene beads were rotated randomly, and small drops (16 to 30 microL) of the reaction mixtures evenly contacted all parts of the solid phase surfaces during the incubations, though only small parts of the solid phase surfaces were contacted at one time. The intent was to continuously mix thin aqueous layers of the reaction mixtures covering the solid phase surfaces with the rest of the reaction mixtures. (Therefore, these immunoassays were called thin aqueous layer immunoassays.) beta-D-Galactosidase activity bound to the polystyrene tubes was assayed by fluorometry for 30 and 60 min. The present immunoassays I and II, in which only 15 to 25 min were used for the immunoreactions, were as sensitive if not more so than the previous immune complex transfer enzyme immunoassay requiring 150 min for the immunoreactions. In these earlier immunoreactions, the immune complex comprising the three components formed by 30 min incubation was trapped onto two polystyrene beads (3.2 mm in diameter) coated with affinity-purified (anti-2,4-dinitrophenyl group) IgG for 60 min, and was then transferred to two polystyrene beads (3.2 mm in diameter) coated with affinity-purified (antihuman IgG y-chain) IgG for 60 min in a total volume of 150 microL. Furthermore, the present (sequential) immunoassay 11 (and probably I) could become approximately 10 times more sensitive by assaying bound beta-D-galactosidase activity for a longer period of time (10 h), since beta-D-galactosidase activity, bound nonspecifically in the presence of serum samples from HIV-1 seronegative subjects, was considerably low.

2,4-Dinitrophenol↗

Immune complex transfer enzyme immunoassay for antibody IgG to HIV-1 gp41 antigen using synthetic peptides as antigens.

The immune complex transfer enzyme immunoassay for antibody IgG to HIV-1 gp41 antigen was developed using two synthetic peptides. An aliquot (10 microl) of serum samples from HIV-1 seropositive subjects was incubated simultaneously with 2,4-dinitrophenyl-bovine serum albumin-synthetic HIV-1 gp41 peptide conjugates and synthetic HIV-1 gp41 peptide-beta-D-galactosidase conjugates and subsequently with colored polystyrene beads coated with affinity-purified (anti-2,4-dinitrophenyl group) IgG to trap the immune complexes formed comprising the three components. After washing, the colored polystyrene beads were incubated with white polystyrene beads coated with affinity-purified (anti-human IgGgamma-chain) IgG in the presence of epsilonN-2,4-dinitrophenyl-L-lysine to transfer the immune complexes to the white polystyrene beads. Beta-D-Galactosidase activity bound to the white polystyrene beads was assayed by fluorometry. The formation, trapping and transferring of the immune complexes were completed within 0.5, 0.5 and 1.5 hr, respectively. Since each peptide appeared to react with its own specific antibody IgG, serum samples were tested by the equimolar combination of the two peptides. The lowest signals (fluorescence intensities for bound beta-D-galactosidase activity) for serum samples from HIV-1 asymptomatic carriers, patients with AIDS-related complex and patients with AIDS were 1490-, 2210- and 1460-fold, respectively, higher than the highest signal for serum samples from HIV-1 seronegative subjects. In five seroconversion serum panels, antibody IgG to HIV-1 gp41 antigen was detected as early as antibodies to HIV-1 detected by three currently commercially available methods.

Acquired Immunodeficiency Syndrome↗

[Treatment of cytomegalovirus retinitis in AIDS with an intraocular sustained-release ganciclovir implant].

Active cytomegalovirus (CMV) retinitis in patients with acquired immunodeficiency syndrome (AIDS) was treated with an intraocular sustained-release ganciclovir implant. A total number of 19 implants were performed in 15 eyes of 9 AIDS patients. The intraocular sustained-release ganciclovir was effective in preventing reactivation of CMV retinitis in 15 of the 19 implants, ineffective in 3, and undetermined in 1. All ineffective cases had been resistant to ganciclovir therapy before the implants. Vision after the therapy was maintained at better than 0.5 except for one eye. There were no serious ocular complications caused by the therapy. Among 5 patients with unilateral CMV retinitis, 2 unaffected eyes developed CMV retinitis during this therapy. In addition, another patient developed presumed CMV infection in other systemic organs. Based on these data, the intraocular sustained-release ganciclovir implant was considered to be useful for the treatment of CMV retinitis in AIDS.

AIDS-Related Opportunistic Infections↗

Identification and characterization of multiple HLA-A24-restricted HIV-1 CTL epitopes: strong epitopes are derived from V regions of HIV-1.

HIV-1-specific CTL has a crucial role in the elimination of the virus. However, a restricted number of common HLA class I alleles has been studied for their presentation of HIV-1 CTL epitopes. We have attempted to identify HIV-1 CTL epitopes presented by HLA-A*2402 using reverse immunogenetics. Fifty-three HLA-A*2402-binding HIV-1 peptides were used to induce specific CTL in PBL of four HIV-1-infected individuals carrying HLA-A24. Twelve peptides were strongly suggested to be HLA-A*2402-restricted HIV-1 CTL epitopes because these peptides induced the specific CTL that killed both the target cells pulsed with the specific peptides and those infected with the vaccinia HIV-1 recombinant virus in at least one HIV-1-infected individual. Of these epitopes, 11 were confirmed by the generation of the specific CTL clones. Six were the Env epitopes while three, one, and one were derived from Gag, Pol, and Nef proteins, respectively. Analysis of 12 HIV-1-infected individuals using these peptides showed that 5 derived from the Env protein and one from the Nef protein were strong epitopes. These strong epitopes were derived from the diverse region of HIV-1 while weak epitopes were conserved in the HIV-1 clade B strain. Analysis of CTL recognition of mutations in these strong epitopes suggested that the mutations in the Env epitopes may critically influence CTL recognition in vivo.

Alleles↗

HIV type 1 V3 variation dynamics in vivo: long-term persistence of non-syncytium-inducing genotypes and transient presence of syncytium-inducing genotypes during the course of progressive AIDS.

We performed a population-based sequence analysis of the envelope V3 region of human immunodeficiency virus type 1 (HIV-1) in two infected hemophiliacs. The study was conducted over 6-9 years, extending from the asymptomatic phase to AIDS. In both patients, serial analysis showed that the V3 population at the initial stage consisted exclusively of putative non-syncytium-inducing (NSI) genotypes. Several of these clones continued to be present without change for many years until the terminal stage and often represented the dominant species in the population at each time interval. On the other hand, syncytium-inducing (SI) genotypes were initially absent but appeared shortly before severe depletion of CD4+ T cells and their proportion in the population appeared to correlate with the viral load. In sharp contrast to NSI genotypes, SI genotypes displayed a significantly shorter presence. Thus, rapid gross population changes were found in SI genotypes, which were particularly frequent in the asymptomatic phase and less frequent in the terminal stage. Furthermore, the ratio of nonsynonymous nucleotide substitutions per synonymous substitutions in the V3 region in SI genotypes was higher than the corresponding value of NSI genotypes and the phylogenetic tree analysis revealed that a longer branch length was observed in SI genotypes than in NSI genotypes. These results suggest that there might be a stronger pressure for selection on SI viruses than on NSI viruses during the high CD4 counts on the contrary to the fact that emergence of SI genotypes was well correlated with the rapid decline of CD4 count.

Acquired Immunodeficiency Syndrome↗

Expression cloning of a cDNA encoding a sulfotransferase involved in the biosynthesis of the HNK-1 carbohydrate epitope.

The HNK-1 carbohydrate epitope is expressed on several neural adhesion glycoproteins and as a glycolipid, and is involved in cell interactions. The structural element of the epitope common to glycoproteins and glycolipids has been determined to be sulfate-3-GlcAbeta1--> 3Galbeta1-->4GlcNAc. The glucuronyltransferase and sulfotransferase are considered to be the key enzymes in the biosynthesis of this epitope because the rest of the structure occurs often in glycoconjugates. Here we describe the isolation of the rat sulfotransferase cDNA via an expression cloning strategy. The clone finally isolated predicts a protein of 356 amino acids, with characteristics of a type II transmembrane protein and with no sequence similarity to other known sulfotransferases. Both the enzyme expressed as a soluble fusion protein and homogenates of cells transfected with the full-length cDNA could transfer sulfate from a sulfate donor to acceptor substrates containing terminal glucuronic acid.

Amino Acid Sequence↗

Cytomegalovirus (CMV) retinitis and CMV antigenemia as a clue to impaired adrenocortical function in patients with AIDS.

OBJECTIVE: To elucidate the relationship between the activity of CMV disease and adrenocortical function in patients with AIDS. DESIGN AND PATIENTS: CMV retinitis and CMV antigenemia assay (CMV-Ag: numbers of polymorphonuclear leukocytes positive for CMV pp65 antigen per 1.5 x 10(5) cells) are the least invasive and easily accessible examinations to assess the CMV disease activity. All HIV-infected patients with CD4+ lymphocyte counts < 50 x 10(6)/l who were admitted to the Research Hospital of the Institute of the Medical Science (University of Tokyo) between May 1995 to April 1996 were included in this study. METHODS: Fundoscopic examination on CMV retinitis and CMV-Ag were chosen as methods to assess CMV activity because of their simplicity. Adrenocortical function was evaluated by basal plasma adrenocorticotropin, plasma cortisol, plasma aldosterone, plasma renin activity, and responses of plasma cortisol and plasma aldosterone to 250 micrograms intravenous cosyntropin [rapid adrenocorticotropin test (RAT)]. RESULTS: Thirty patients were enrolled in this study with a maximum CD4+ lymphocyte count of 32 x 10(6)/l. Eleven out of 30 patients showed impaired RAT response (37%). Fourteen out of 30 patients had CMV retinitis. A significant correlation was found between the presence of CMV retinitis and subnormal cortisol response (P < 0.005). Sixteen out of the 30 patients were CMV-Ag-positive. A significant correlation was found between CMV-Ag positivity and subnormal cortisol response to RAT (P < 0.005). CMV-Ag levels in the patients with subnormal cortisol response to RAT were significantly higher than those with normal response (P < 0.001). Importantly, five patients with subnormal cortisol response but not overt adrenal insufficiency at the time of RAT developed overt disease shortly afterwards. Autopsy was performed in six patients with subnormal cortisol response and showed multiple inclusion bodies indicative of CMV adrenitis. CONCLUSION: The adrenal gland is most frequently affected by CMV in AIDS patients. Our result suggests that CMV retinitis or CMV-Ag positivity independently serve as an indication of possible adrenal dysfunction.

AIDS-Related Opportunistic Infections↗

Molecular cloning and functional expression of a cDNA encoding a new member of mixed lineage protein kinase from human brain.

We have cloned a novel protein kinase from human cerebellum and named it LZK (leucine zipper-bearing kinase). The LZK cDNA encoded a 966-amino acid polypeptide that contains a kinase catalytic domain and double leucine/isoleucine zippers separated by a short spacer region. The amino acid sequence of the kinase catalytic domain was a hybrid between those in serine/threonine and tyrosine protein kinases, indicating that LZK belongs to the subfamily of the mixed lineage kinase (MLK) family. The kinase catalytic domain of LZK was most similar to DLK (Holtzman, L. B., Merritt, S.E., and Fan, G. (1994) J. Biol. Chem. 269, 30808-30817), MUK (Hirai, S., Izawa, M., Osada, S., Spyrou, G., and Ohno, S. (1996) Oncogene 12, 641-650), and ZPK (Reddy, U. R., and Presure, D. (1994) Biochem. Biophys. Res. Commun. 202, 613-620), which belong to the same subfamily of the MLK family. However, besides the kinase catalytic domain and double leucine/isoleucine zippers, there was no significant homology with known proteins. The recombinant LZK autophosphorylated in the presence of ATP and divalent cations, and exhibited serine/threonine kinase catalytic activity. Northern blot analysis revealed that LZK is expressed most strongly in the pancreas, with a pattern that differs from other MLKs. Expression of LZK in COS7 cells induced phosphorylation of c-Jun and activation of JNK-1, indicating the association of LZK in the c-Jun amino-terminal kinase/stress-activated protein kinase pathway. The expressed LZK was detected primarily in the membrane fraction, suggesting that LZK interacts with other cellular components in vivo.

Amino Acid Sequence↗

Cloning and functional expression of a novel glucuronyltransferase involved in the biosynthesis of the carbohydrate epitope HNK-1.

The HNK-1 carbohydrate epitope is characteristically expressed on a series of cell adhesion molecules and also on some glycolipids in the nervous system over a wide range of species from insect to mammal. The HNK-1 epitope is involved in cell-cell and/or cell-substrate interaction and recognition during the development of the nervous system. In this study, we isolated a novel glucuronyltransferase from rat brain, which is a key enzyme of the biosynthesis of the HNK-1 epitope on glycoproteins. Based on the partial amino acid sequences, we isolated cDNA encoding the glucuronyltransferase. The primary structure deduced from the cDNA sequence predicted a type II transmembrane protein with 347 amino acids and had no detectable similarity with any other proteins of known functions, including glucuronyltransferases of the liver and olfactory epithelium. Expression of a soluble recombinant form of the enzyme in COS-1 cells produced an active glucuronyltransferase. The selective expression of the glucuronyltransferase gene in the nervous system was consistent with the almost exclusive localization of the HNK-1 epitope in the nervous system. Transfection of the glucuronyltransferase cDNA into COS-1 cells induced not only expression of the HNK-1 epitope on the cell surface but also marked morphological changes of the cells, suggesting that the HNK-1 epitope associates with the cell-substratum interaction.

Amino Acid Sequence↗

Evidence of presentation of multiple HIV-1 cytotoxic T lymphocyte epitopes by HLA-B*3501 molecules that are associated with the accelerated progression of AIDS.

We recently showed HLA-B35-restricted CTL activity for 10 HIV-1 epitopes in PBL from two HIV-1-infected individuals. In the present study, we established CTL clones specific for nine of these HIV-1 epitopes to confirm these HLA-B35-restricted epitopes. The specific CTL clones effectively killed the HLA-B*3501-positive target cells infected with the HIV-1 vaccinia recombinant virus. These results confirmed that nine HIV-1 CTL epitopes are presented by HLA-B*3501 molecules. The CTL activity specific for four Pol and two Nef epitopes was induced in the peptide-stimulated PBL from three or more of seven HIV-1-infected individuals, indicating that these six are common epitopes. Eight were considered strong epitopes because the specific CTL activity was detected in the cultured PBL that was once stimulated with peptides. Thus, the present study excluded the possibility that the disability of the presentation of HIV-1 epitopes by HLA-B35 molecules is associated with the accelerated progression of AIDS in HLA-B35-positive individuals. Analysis of mutated epitopes found in an HIV-1 type B strain using the CTL clones revealed that most mutated epitopes partially or markedly affect the recognition of CTL clones. Of 19 mutations that affected recognition of the CTL clones, 7 reduced peptide-HLA-B*3501 binding, while 12 affected TCR recognition. These results indicate that natural mutations of HLA-B35-restricted HIV-1 CTL epitopes affect the recognition of CTL by mechanisms that reduce both peptide binding and TCR recognition.

Acquired Immunodeficiency Syndrome↗

Renal expression of serum-type mannan-binding protein in rat.

Mannan-binding proteins (MBPs) occur as liver and serum forms, which are encoded by separate genes and synthesized by the liver. Serum MBP plays a role in the first defense against a variety of pathogens. We found in this study, by reverse-transcriptional PCR, that rat serum MBP mRNA but not liver MBP is also expressed in the kidney. The level of the serum mRNA expression in the kidney as estimated by competitive PCR was about one-eighth that of the liver. Transcripts of serum MBP were detected in the renal corpuscles and distal convolutions by in situ hybridization. Affinity chromatography of the extract of rat kidney on a column of Sepharose-4B-mannan isolated a 29-kDa protein. These results indicate that serum MBP is synthesized in the kidney as well as in the liver. The kidney protein may be associated with local host defense around the kidney.

Animals↗

More sensitive immune complex transfer enzyme immunoassay for antibody IgG to p17 of HIV-1 with shorter incubation time for immunoreactions and larger volumes of serum samples.

In the previous immune complex transfer enzyme immunoassay for antibody IgG to p17 of HIV-1, the immune complex comprising 2,4-dinitrophenyl-bovine serum albumin-recombinant p17 conjugate, anti-p17 IgG, and recombinant p17-beta-D-galactosidase conjugate was trapped onto polystyrene beads coated with (anti-2,4-dinitrophenyl group) IgG by overnight incubation and was transferred to polystyrene beads coated with (antithuman IgG gamma-chain) IgG by 3 hr incubation in the presence of excess of epsilon N-2,4-dinitrophenyl-L-lysine. These processes were made efficient by incubation with shaking and by using solid phases with larger surface areas. In addition, the volume of serum samples used was increased from 10 microliters to 100 microliters. As a result, the sensitivity was improved 20-30-fold and was approximately 100,000-fold higher than that of Western blotting for p17 band, even when both trapping and transferring of the immune complex were performed for only 30 min. Furthermore, testing many samples became easily possible with higher sensitivity using microplates and a fluororeader.

2,4-Dinitrophenol↗

Effect of maternal meal ingestion on fetal renal artery resistance.

OBJECTIVE: To examine whether maternal meal ingestion affects the fetal circulation in uncomplicated pregnancies. METHODS: A simple crossover blinded study was designed for late uncomplicated singleton pregnancies. After overnight fasting, two different maternal meal states were tested. In one state, pregnant women had a standard 600-kcal breakfast at 8 AM (phase A). The other state consisted of maintaining fasting (phase B). Both states were assigned to each woman within 3 days in randomized order. Fetal Doppler studies of the umbilical, middle cerebral, and renal arteries and the descending aorta were performed at 7 AM (the fasting state) and at 10 AM (the fed state or the continuous fasting state). RESULTS: Twenty women underwent the crossover study. Regardless of the maternal meal state, no significant change was observed in the pulsatility index (PI) of either the umbilical artery (n = 20), the middle cerebral artery (n = 19), or the descending aorta (n = 15). However, the PI of the fetal renal artery decreased significantly after maternal meal ingestion (n = 14) (phase A, 2.36 +/- 0.16 versus 2.09 +/- 0.33; P = .021). There was no such change in the PI after prolonged fasting (phase B, 2.44 +/- 0.32 versus 2.39 +/- 0.44; P = .75). CONCLUSION: Fetal renal artery resistance decreased after maternal meal ingestion in normally grown fetuses during late pregnancy. This decrease in the resistance may be associated with increased fetal urine production after maternal meals.

Adult↗