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Biomedical subjects

M Sakaguchi

Publications and source records attributed to M Sakaguchi.

At least 289 records · Page 16Linked to original sources
PubMed1994

Tympanometric changes following acute otitis media in Japanese children.

Using tympanometry we investigated potential changes in both middle ears developing during and after unilateral acute otitis media (AOM) in Japanese children. In 144 children with unilateral (AOM), tympanometry was performed at presentation and was repeated at the 1st, 2nd, 3rd, and 4th weeks and then every 2 weeks up to 12 weeks after entry into the study. Type B tympanograms were recorded in 81 (56%) of the affected ears and in 37 (26%) of the unaffected ears at presentation. Twelve weeks after AOM, the type B tympanogram was still observed in 21 (15%) of the affected ears and in 16 (11%) of the unaffected ears. Ears with type B changes at presentation showed a significantly slower recovery of middle ear ventilation than did those with either type A or type C1.

Acoustic Impedance Tests↗
PubMed1994

Expression of a novel Marek's disease virus type 1 (MDV1)-specific protein p40 in insect cells by a baculovirus vector and in chick embryo fibroblasts infected with MDV1.

We found that the open reading frame of 1053 nucleotides within the short unique sequence of Marek's disease virus (MDV) type 1 (MDV1) expresses a 40 kDa protein, using a baculovirus vector in insect cells. Mouse antisera against the 40 kDa protein reacted with a 40 kDa protein in MDV1-infected cells. A cross-reactive polypeptide of 37 kDa was also detected in cells infected with herpesvirus of turkey.

Animals↗
PubMed1994

Bio-anticlastogenic effects of unsaturated fatty acids included in fish oil--docosahexaenoic acid, docosapentaenoic acid, and eicosapentaenoic acid--in cultured Chinese hamster cells.

Bio-anticlastogenic effects of unsaturated fatty acids--cis-4,7,10,13,16,19-docosahexaenoic acid (DHA), cis-7,10,13,16,19-docosapentaenoic acid (DPA), and cis-5,8,11,14,17-eicosapentaenoic acid (EPA)--on chemically induced chromosome aberrations were studied in cultured Chinese hamster cells. The induction of chromosome aberrations by the crosslinking agents mitomycin C (MMC) and cisplatin (DDP), the SN-1 type alkylating agents N-ethyl-N'-nitro-N-nitrosoguanidine (ENNG), methyl nitrosourea (MNU), and ethyl nitrosourea (ENU), and the SN-2 type alkylating agent ethyl methanesulfonate (EMS), but not by the SN-1 type alkylating agent N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and the SN-2 type alkylating agent methyl methanesulfonate (MMS), was suppressed by post-treatment with DHA, DPA, and EPA. Since there was no opportunity to inactivate mutagens by desmutagenic mechanisms under the post-treatment schedule used, the results demonstrate the bio-anticlastogenicity of unsaturated fatty acids. Suppression by the unsaturated fatty acids was observed when cells were treated during the G2 phase, suggesting that G2 events were responsible for the bio-anticlastogenic effects. Two saturated fatty acids with the same number of carbons as the studied unsaturated fatty acids--docosanoic acid and eicosanoic acid--did not affect chromosome aberration induction, suggesting the necessity of unsaturation for fatty acid bio-anticlastogenicity.

Alkylating Agents↗
PubMed1994

Changes with aging in head and center of foot pressure sway in children.

To quantitate the development of equilibrium in children, we investigated movements of the head and of the center of foot pressure (COF) in standing subjects, using a cephalograph, a force measuring platform, and a technical computer. We studied 126 subjects, 105 healthy children, aged 4-18 years, and 21 adults, aged 20-28 years. Each subject stood with their feet together on a platform for 60 s each with eyes open or closed. The area and total length of head and COF movements decreased with increasing age, and were significantly greater in children under 12 years than in adults. The ratio of the lengths of head to COF movements was significantly larger in children under 9 years than in adults. The ratio of the anteroposterior to lateral movement of COF was also larger in children under 9 years. These observations suggested that body sway in children was not only larger than that in adults, but different in nature.

Adolescent↗
PubMed1994

Antagonizing effect of triphenyltin chloride on cytosine-1-beta-D-arabinofuranoside potentiation of chromosome aberrations induced by mitomycin C.

We previously reported that the organotin triphenyltin chloride (TPTC), which has been widely used as an anti-fouling coating for fishing nets and ship bottoms, potentiated clastogen-induced chromosome aberrations during the G2 phase of the cell cycle. In this communication, CHO cells treated with mitomycin C (MMC) were post-treated with TPTC in the presence and absence of other agents--cytosine-1-beta-D-arabinofuranoside (araC), hydroxyurea, or caffeine--having a similar effect during the G2 phase of the cell cycle. The potentiating effect of araC was completely inhibited in the presence of TPTC at the concentration at which TPTC showed its potentiating effect, suggesting that potentiating effects of TPTC and araC are antagonistic. On the other hand, combined treatment with TPTC and caffeine or hydroxyurea showed a potentiating effect almost equal to the sum of the potentiating effects of each given separately.

Animals↗
PubMed1994

Construction of recombinant Marek's disease virus type 1 (MDV1) expressing the Escherichia coli lacZ gene as a possible live vaccine vector: the US10 gene of MDV1 as a stable insertion site.

This paper describes the construction of a recombinant Marek's disease virus serotype 1 (MDV1) in which the Escherichia coli lacZ gene was inserted into the open reading frame homologous to the US10 gene of herpes simplex virus 1 (HSV1). The recombinant virus replicated as well in cell culture as the parental MDV1 K-554 strain. Chickens immunized with the virus were protected against challenge with virulent MDV1, and produced a high level of antibodies against beta-galactosidase as well as against MDV1 antigens. The antibody titres persisted for at least 16 weeks. These results demonstrate that the US10 gene of MDV1 is an effective site for the insertion of foreign genes from which to construct a polyvalent live vaccine for poultry.

Animals↗
PubMed1994

Acute pharyngitis, an unusual complication of intravenous hyperalimentation.

While the numerous complications of intravenous hyperalimentation (IVH) are well recognized, we encountered a unique one. A 60-year-old man developed a sore throat, neck pain and fever seven days after catheterization of the subclavian vein to provide post-operative nutrition. Marked swelling was visible at the right posterior wall of this oropharynx and hypopharynx. X-ray of the neck revealed that the tip of the catheter was positioned in the internal jugular vein, not the subclavian vein as intended. The acute pharyngitis, diagnosed as due to phlebitis of the internal jugular vein due to the malpositioned catheter, subsided within two days of catheter removal.

Acute Disease↗
PubMed1994

cDNA cloning and characterization of mitochondrial import stimulation factor (MSF) purified from rat liver cytosol.

We identified a liver cytosolic protein factor that stimulated the import of wheat germ lysate-synthesized precursor proteins into mitochondria. It was termed mitochondrial import stimulation factor or MSF [Hachiya, N. et al. (1993) EMBO J. 12, 1579-1586]. It consisted of 32-kDa (MSFL) and 30-kDa (MSFS) polypeptides as assessed by SDS-PAGE. MSF recognized the presequence portion of mitochondrial precursor proteins and catalyzed the depolymerization and unfolding of in vitro synthesized mitochondrial precursor proteins in an ATP-dependent manner. We report here the cDNA cloning and characterization of MSF. Microsequencing of MSFL and MSFS showed that they belonged to a highly conserved, widely distributed eukaryotic protein family, collectively designated as 14-3-3 proteins. We cloned the cDNA of MSFL and that of one component of MSFS (MSFS1) from a rat liver cDNA library. The cloned cDNAs were separately expressed in Escherichia coli and the expressed proteins were purified to homogeneity. The purified recombinant MSFL and MSFS1 stimulated mitochondrial import of adrenodoxin precursor (pAd) synthesized in vitro with wheat germ lysate translation system. Recombinant MSFL or MSFS1 had the ability to bind with denatured pAd and they kept the precursor in an import-competent state. Rabbit polyclonal antibodies raised against the recombinant proteins inhibited the import-stimulation activity of rat liver cytosol as well as that of authentic purified MSF. Identification of MSF as 14-3-3 proteins establishes a novel function for this family of proteins and indicates their role as cytosolic chaperones to aid many important cellular events.

14-3-3 Proteins↗
PubMed1994

Estimation of Der p and Der f I quantities in the reference preparations of Dermatophagoides mite extracts.

A monoclonal antibody-based enzyme-linked immunosorbent assay (MoAb-ELISA) was developed to measure the major Dermatophagoides mite allergens, Der p I and Der f I. The assay was highly species-specific and sensitive. Using this assay system, the absolute mass unit of Der p I and Der f I in the reference preparations of the extracts was estimated. The primary standards used were the purified Der p I and Der f I preparations. The reference preparations of the D. pteronyssinus and D. farinae extracts (92-Dp and 92-Df), which had been prepared from the same amount of mite bodies of both species, were found to contain the same levels of the Der I allergens, 10.1 micrograms/ml of Der p I and 10.0 micrograms/ml of Der f I, respectively. A histamine release assay with leucocytes from mite-allergic donors showed that the total allergenic potency of 92-Dp and 92-Df was comparable. This results indicates that the estimated Der I levels in these extracts seem to be valid, at least, in the balance between the two species, although further comparisons of the absolute quantities by several different laboratories are needed. The Der I levels in the WHO/IUIS international reference preparation of D. pteronyssinus and the CBER standard mite extracts, E4-Dp and E5-Df, were also estimated using this assay system. They were found to contain 4.4 micrograms/vial and 13.3 micrograms/ml of Der p I and 9.5 micrograms/ml of Der f I, respectively.

Allergens↗
PubMed1994

A case of siblings with Meckel's diverticulum diagnosed before operation.

The authors encountered a sibling case of Meckel's diverticulum in 9 and 11 year old Japanese boys. They were diagnosed using contrast examination and 99mTc-pertechnetate scintigraphy before operation. The familial tendency is one in every 2500 families. Only 15 cases of familial occurrence have been reported by five authors.

Anastomosis, Surgical↗
PubMed1994

A new system that analyzes erythropoietin-mediated early signal transduction: transfection of the c-fos enhancer.promoter-luciferase gene into a murine erythroid cell line.

Erythropoietin (Epo) exerts its effects by binding specific receptors on the surface of reactive cells. However, the signal transduction system after binding has not been well described. To develop a system to analyze the steps of signal transduction, we transfected the human c-fos-enhancer/promoter linked with the Photinus pyralis luciferase gene (pfosluc2) into a murine erythroleukemia cell line ELM-I-1, in which we previously showed that c-fos mRNA is rapidly induced upon Epo-stimulation. A stable transfectant was obtained. The cells transfected with pfosluc2 were stimulated with Epo and luciferase activity in the cells was measured as light intensity. The light intensity integrated for 2 min (LI2.0) was 3202 +/- 80 unit/1.5 x 10(5) cells before stimulation. This increased up to 5869 +/- 321 unit/1.5 x 10(5) cells by incubating the cells with 5 U/ml Epo for 2 h. After Epo stimulation, light intensity began to increase at 30 min, reached a peak (about 1.8 times the basal level) at 120 min, and then gradually dropped. The effect of Epo was dose-dependent; significant action occurred at as low as 0.5 U/ml, with a maximum at 5 U/ml. A similar response was observed when the cells were stimulated with interleukin-3 (IL-3) although the response was apparently lower than that with Epo. It was also found that IL-3 had an additive action with Epo on c-fos activity in this system. Thus, the above method was proven to be simple, rapid and sensitive enough to use to determine the early phase of signal transduction of Epo.

Animals↗
PubMed1994

HCV-marker-positive autoimmune-type chronic active hepatitis: a possible relation between HCV infection and liver autoreaction.

This study focused on 32 patients who were diagnosed as having autoimmune hepatitis based upon clinical and histological factors. Fifteen of these patients were positive for HCV-RNA and for one of the HCV-related markers tested, including anti-C100, ELISA II, and RIBA 2 (Group 2). The remaining 17 patients were negative for all HCV-related markers (Group 1). Clinical factors in the two groups, including the frequency of autoantibodies, serum levels of aminotransferase and gammaglobulin, HLA phenotypes, and the response to corticosteroid treatments, were compared. The titer of serum anti-nuclear antibodies and the level of serum aminotransferase at initial diagnosis were significantly higher in Group 1 than in Group 2. Furthermore, the genetic background of the two groups, as indicated by HLA phenotypes, differed. All cases in Group 1 were HLA-DR4-positive, whereas only 60% of those in Group 2 cases had HLA-DR4. Also, all cases in Group 1 but only 66.7% of the cases in Group 2 showed good clinical responses to corticosteroid treatment. Finally, no cases of HCV-related-marker-positive autoimmune hepatitis (Group 2) had antibodies for LKM, suggesting that these cases were clinically different from type II autoimmune hepatitis. These data indicated that immunosuppressive treatment might be the preferred initial treatment in patients who either satisfy the criteria for AIH or who are sero-positive for an HCV-marker.

Autoantibodies↗
PubMed1994

Prevalence of IgE antibody to crude and purified allergens of Japanese cedar pollen among different troops of Japanese monkeys (Macaca fuscata).

We measured specific IgE antibodies to the crude allergen as well as two purified allergens (Cry j I and Cry j II) of Japanese cedar (Cryptomeria japonica--CJ) pollen in the serum of 276 Japanese monkeys in nine troops. Of 45 monkeys with CJ specific IgE in eight of nine troops, 23 (51%) were found to have IgE to both Cry j I and Cry j II, 21 (47%) only to Cry j I, and one (2.2%) only to Cry j II. The positive rate of specific IgE antibody to each allergen varied among the troops.

Allergens↗
PubMed1994

Distention of the uterus activates its multiple pacemakers and induces their coordination.

In the pregnant human uterus, pacemaker activities and their coordination processes were studied in labor induced by uterine distention. Electrical and mechanical activities of the uterus were simultaneously recorded in 6 midtrimester (normal, n = 4; fetal death, n = 2) and 8 term (normal, n = 7; fetal death, n = 1) patients. Initially, frequent and sporadical spike discharges which did not synchronize with low magnitude and irregular mechanical activities were noted. With time, synchronization of both activities developed. These findings were noted regardless of the gestational stage of the patient and fetal viability. The patterns of development and decreases in mechanical and electrical activities, together with their synchronization patterns, were positively and negatively controlled by uterine distention and its suspension, respectively. These results suggest that the uterus has multiple pacemakers in various locations, and uterine distention works as a trigger for the elevation of excitability and for coordinated and orthodromic activities.

Adult↗
PubMed1994

Three isoforms of platelet-derived growth factors all have the capability to induce angiogenesis in vivo.

Three isoforms of platelet-derived growth factors (PDGFs) composing of AA, AB, and BB chains all exhibited angiogenic activity in a dose-dependent manner in an in vivo assay system involving the chorioallantoic membrane of chick embryo. The order of potency as BB > AB = AA. They, however, failed to stimulate proliferation of vascular endothelial cells, suggesting that their effects are indirect. These data suggest that possibility that three PDGF isoforms are indirect angiogenic factors.

Animals↗
PubMed1994

Formaldehyde-fixed cells infected with pseudorabies virus conferred resistance against Aujeszky's disease.

Cells infected with Pseudorabies virus (PrV) and fixed with formaldehyde were evaluated as a vaccine against Aujeszky's disease. Mice and pigs inoculated with fixed cells showed no clinical signs. In a challenge test, all fixed cells conferred protection on mice and pigs. Although pigs showed slight symptoms, they were restored to normal health within a few days. These results demonstrate that PrV-infected cells fixed with formaldehyde function as a vaccine against Aujeszky's disease and serve as a novel type of vaccine which is easy to make, and is both safe and effective.

Animals↗
PubMed1994

Removal of cat major allergen (Fel d I) from futon (Japanese bedding) with a home washing machine.

We evaluated the removal of a cat major allergen (Fel d I) from futons (Japanese bedding) with the use of a large-sized home washing machine. Before and after washing a futon that had been used in a home with a cat, a small amount of cotton was collected from the futon and Fel d I was extracted from the cotton. The levels of Fel d I were assayed by a sandwich enzyme-linked immunosorbent assay (ELISA). We found that washing reduced the Fel d I level in futons by more than 95%. In conclusion, washing of futons is an effective method for elimination of their cat allergens.

Allergens↗