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Biomedical subjects

H Hatta

Publications and source records attributed to H Hatta.

At least 37 records · Page 2Linked to original sources
PubMed1997

Passive immunization against dental plaque formation in humans: effect of a mouth rinse containing egg yolk antibodies (IgY) specific to Streptococcus mutans.

Passive immunization involving the delivery of antibodies specific to pathogens of infectious diseases to the host has been an attractive approach to establish protective immunity against a variety of microbial pathogens, including Streptococcus mutans, which is the principal etiologic agent of dental caries in humans. The overall purpose of the present study was to determine the effectiveness of a mouth rinse containing antibodies to S. mutans in preventing the establishment of this bacterium in dental plaque of humans. The antibodies were derived from egg yolks obtained from hens immunized with whole cells of S. mutans grown in sucrose-containing medium. The immunoglobulin derived from the yolks (IgY) of immunized hens was characterized in vitro and in vivo in human volunteers. Cross-reactivity tests showed that immune IgY reacted with every serotype, except serotype b, which had lost its GTase activity, when the bacteria were cultured in sucrose-containing medium. Immune IgY inhibited S. mutans adherence to saliva-coated hydroxyapatite discs by 59.2%, while control IgY caused an inhibition of only 8.2%. In the short-term (4-hour) test using a mouth rinse containing 10% sucrose, immune IgY decreased the ratio of the percentage of S. mutans per total streptococci in saliva. In the long-term (7-day) test using a mouth rinse without sucrose, the ratio in saliva was not significantly reduced in the volunteers using the immune IgY due to the large standard deviation. However, comparing the ratios of the percentage of S. mutans per total streptococci in plaque of individual subjects, there was a tendency for a reduction of the ratios in the volunteers receiving the mouth rinse containing immune IgY. These results support the effectiveness of IgY with specificity to S. mutans grown in the presence of sucrose as an efficient method to control the colonization of mutans streptococci in the oral cavity of humans.

Antibodies, Bacterial↗
PubMed1997

Branch geometry in Cornus kousa (Cornaceae): computer simulations.

Computer simulations similar to actual trees were constructed using simple branching rules. Branch orientation with respect to the direction of gravity was a fundamental consideration. In Cornus kousa BUERG. ex HANCE, several types of branches develop from winter buds, varying from orthotropic shoots to plagiotropic ones. Based on actual observations and measurements of branching structures with a wide range of orientations, we made a flexible geometrical model consisting of five forking branches that varied in outgrowth depending on the direction of the shoot with respect to gravity. Repetition of the branching by computer generated a realistic tree pattern, which was close to the shape of a young C. kousa tree. Reproductive shoots seem to be under a branching rule that was a modification of vegetative branching, although the reproductive branch size was considerably smaller than the vegetative one, and reproductive branching was bifurcated instead of five-forked. We conclude that all branchings in orthotropic and plagiotropic shoots in the vegetative phase and shoots in the reproductive phase are formed under the same branching rule, but each has different parameter values.

Computer Simulation↗
PubMed1997

[Association of participation in health checkups with medical service utilization in a rural town].

Association of participation in health checkups in 1983-94 with medical service utilization in 1989-94 was studied. The study subjects consisted of 1,198 males and 1,247 females aged 30 years or over, who were members of the National Health Insurance in a rural town in Kyoto prefecture. One hundred and four males and 95 females died during 1989-94. Cumulative death rates were higher among both males and females with less participation in checkups than among those with higher participation, however, there was no difference seen for medical service utilization. Regarding subjects alive in 1994, both males and females who participated frequently in checking in 1983-88 also visited medical facilities more frequently and had higher medical costs in 1989-94 than those with less frequent participation. Similar analysis for checkups in 1989-94, showed that only females had that tendency. Among participants in checkups in 1989-94, there were smaller numbers of hypertensives, current smokers, and current drinkers than among non-participants, therefore, the participants are thought to have decreased their risk for chronic diseases. In conclusion, frequent participation in health checkups are thought to increase medical utilization even with a lower prevalence or risk of chronic diseases.

Adult↗
PubMed1996

Anti-erythropoietin receptor monoclonal antibody: epitope mapping, quantification of the soluble receptor, and detection of the solubilized transmembrane receptor and the receptor-expressing cells.

A hybridoma cell line producing the monoclonal antibody against erythropoietin receptor (EpoR) was established using the soluble ectodomain of mouse erythropoietin receptor (sEpoR) as an antigen. The monoclonal antibody termed 1G3 bound to the denatured sEpoR. Epitope mapping with peptide library revealed that 1G3 recognized the amino terminal region including the hexapeptide (positions 6 to 11; LeuProAspProLysPhe). The amino acid sequence in this hexapeptide was identical in mice, rats, and humans, and therefore 1G3 bound to EpoR from all of these sources. Using 1G3, we evaluated sEpoR by a sandwich enzyme-linked immunoassay, and EpoR in the solubilized membrane preparation was detected by Western blotting. The cells expressing EpoR were identified with immunochemical staining. We confirmed the presence of EpoR in a neuronal cell line and PC12 cells, and EpoR was expressed in primary cultured hippocampal neurons.

Amino Acid Sequence↗
PubMed1996

Passive immunity against diarrhoea.

Passive immunity against a variety of respiratory and gastrointestinal pathogens has recently been increasingly used clinically, and oral administration of antibodies of both human and non-human origin has been tried both for prophylaxis and treatment of infections. Although the former type of therapy has been shown to be effective, data on the latter are still scarce. This commentary focuses on recent studies on successful oral therapeutic administration of bovine immunoglobulins.

Animals↗
PubMed1996

[Validation of the hospital anxiety and depression scale in a gastro-intestinal clinic].

This study examined the validity of the Japanese version of the hospital anxiety and depression scale (HAD) in a gastro-intestinal outpatient clinic. One hundred and twenty-three men and 142 women consulting a gastro-intestinal outpatient clinic at a primary care hospital in Kyoto during 1995 were surveyed. Item-remainder correlation and internal consistency were examined for reliability. Concurrent validities were examined using the stait-trait anxiety inventory (STAI) and Zung's self-rating depression scale (SDS). The prevalence of psychiatric disorder in this population ranged from 27% to 39%. Cronbach's coefficients were greater than 0.8 for the anxiety subscale and more than 0.7 for the depression subscale. Spearman's correlation of the anxiety subscale scores and the STAI were r = 0.678 for men, and r = 0.717 for women. The correlation of depression subscale scores and SDS were r = 0.457 for men, and r = 0.565 for women. It is suggested that the use of the HAD to general hospital outpatients clinic would facilitate detecting emotional disorders in outpatients.

Adult↗
PubMed1995

[Characteristics of smoking, drinking, dietary habits, and physical exercise in health behavioral models].

Various kinds of preventive health behaviors are promoted by health education. The extent of behavioral modification achieved, however, obviously differs from individual to individual according to habits, one of the reasons being the characteristics of various health habits are perceived differently. This cross-sectional study examined the association of indices representing health behavior models with smoking, drinking, dietary habits, and physical exercise. The indices and their meaning were as follows; health locus of control (HLC) and saliency of health are thought to cause the most active behavioral change, health norm relatively passive change, and vulnerability to illness the most passive change. The indices and lifestyle (health related practices) were surveyed by a self-administered questionnaire in a rural town in March 1994. The study sample consisted of 1,010 males and 1,055 females aged 20 years or older who responded to all questions related to the indices. Results are as follows: 1) Smoking and alcohol drinking were associated with vulnerability to illness, suggesting that people who quit smoking or alcohol drinking do so because of perception of their association with illness. Alcohol drinking seemed to have a higher magnitude of being associated with becoming ill or with fear of illness than smoking. 2) Consuming green-yellow vegetables and fresh fish, and physical fitness were associated with internal HLC, saliency of health, and health norm. These habits appeared to be easy to modify by active personal behavior choice. 3) Consuming milk, yogurt, boiled beans, tofu, oranges, and other fruits were associated with saliency of health. These habits seemed to relate to personal sense of being "healthy". 4) It seemed that younger people more likely changed their behavior by active self-management, while, older people changed due to their sense of value or norm. While it is important for health education to promote "self-management of health" by active behavioral change, certain habits are more resistant to change despite educational efforts possibly because of their characteristics in health behavioral models. For cases such as these, techniques promoting passive behavioral change should be considered.

Adult↗
PubMed1993

Oral passive immunization effect of anti-human rotavirus IgY and its behavior against proteolytic enzymes.

The neutralization titer of anti-human rotavirus (HRV) IgY was completely inactivated by pepsin at pH 2.0. However, it was not significantly affected by trypsin or chymotrypsin under certain conditions. The immunological activity of the IgY was observed in the intestine of suckling mice for 2 h after oral administration and the activity rapidly decreased thereafter. The effects of oral supply of IgY were thus estimated for HRV-induced diarrhea in suckling mice and it was found that a previous supply of the IgY (1 h before HRV infection) completely prevented the HRV-induced diarrhea. The preventive effect was decreased as the time gap between IgY administration and HRV infection was longer. However, the oral supply of the IgY within 24 h after HRV infection was still effective and decreased the incidence of HRV diarrhea in suckling mice.

Administration, Oral↗
PubMed1993

Productivity and some properties of egg yolk antibody (IgY) against human rotavirus compared with rabbit IgG.

Productivity and some properties of anti-Human Rotavirus (HRV) hen egg yolk antibody (IgY) were compared with those of anti-HRV rabbit serum antibody (IgG). The hens immunized with HRV (Wa strain, serotype 1 and Mo strain, serotype 3) were found to continuously to lay eggs without any change in the egg laying rate and the yolk of the eggs laid over a year showed a high level of neutralization titer against HRV. The production of anti-HRV IgY by a hen (one year) was at least 15 times (anti-Wa) and 120 times (anti-Mo) more effective than those by an immunized rabbit in the neutralization titer of the antibodies. The stability of anti-HRV IgY at temperature above 70 degrees C and low pH 2-3 was less than that of anti-HRV rabbit IgG. The temperature corresponding to the maximum of denaturation endotherm (Tmax) of IgY was 73.9 degrees C while that of rabbit IgG was 77.0 degrees C in the analysis by differential scanning calorimetry. This discrepancy in heat and acidic pH stability found between the two antibodies as discussed with regard to their protein structures.

Animals↗
PubMed1992

Molecular stability of chicken and rabbit immunoglobulin G.

Molecular stability of chicken egg yolk immunoglobulin G (IgY) and that of rabbit IgG were compared by measuring antibody activities and conformational changes. Stability of rabbit IgG to acid denaturation was much higher than that of IgY. Conformation of the IgY molecule was readily changed in acidic conditions, resulting in a rapid loss of antibody activity. Much less stable natures of IgY to heat-treatment and guanidine-HCl denaturation than rabbit IgG were also observed. Differences in the structure between the two immunoglobulins that might participate in their different stability were inferred from their amino acid sequence data. Importance of the intramolecular disulfide linkage in the rabbit light chain and some other structural differences were suggested.

Animals↗
PubMed1992

Effect of DCA administration or endurance training on lactate metabolism in mice during and after exercise.

The purpose of this study was to investigate the effect of the activation of tissue oxidative capacity by dichloroacetate (DCA) administration or endurance training on oxidative removal of lactate, which is the major pathway of lactate metabolism, in mice during prolonged exercise and after supramaximal exercise. DCA administration significantly decreased the blood lactate concentration and activated the oxidative removal of lactate during prolonged exercise. DCA administration did not change lactate metabolism in mice after supramaximal exercise. Endurance training significantly decreased the blood lactate concentration during prolonged exercise and also activated the oxidative removal of lactate. Endurance training significantly increased the recovery of the blood lactate concentration after supramaximal exercise, while it did not activate the oxidative removal of lactate. These results suggest that the activation of the tissue oxidative capacity decreases the blood lactate concentration and also can activate the oxidative removal of lactate during prolonged exercise, while it does not activate the oxidative removal of lactate after supramaximal exercise.

Animals↗
PubMed1991

Structures of asparagine-linked oligosaccharides from hen egg-yolk antibody (IgY). Occurrence of unusual glucosylated oligo-mannose type oligosaccharides in a mature glycoprotein.

Asparagine-linked oligosaccharides present on hen egg-yolk immunoglobulin, termed IgY, were liberated from the protein by hydrazinolysis. After N-acetylation, the oligosaccharides were labelled with a UV-absorbing compound, p-aminobenzoic acid ethyl ester (ABEE). The ABEE-derivatized oligosaccharides were fractionated by anion exchange, normal phase and reversed phase HPLC, and their structures were determined by a combination of sugar composition analysis, methylation analysis, negative ion FAB-MS, 500 MHz 1H-NMR and sequential exoglycosidase digestions. IgY contained monoglucosylated oligomannose type oligosaccharides with structures of Glc alpha 1-3Man7-9-GlcNAc-GlcNAc, oligomannose type oligosaccharides with the size range of Man5-9GlcNAc-GlcNAc, and biantennary complex type oligosaccharides with core region structure of Man alpha 1-6(+/- GlcNAc beta 1-4)(Man alpha 1-3)Man beta 1-4GlcNAc beta 1-4(+/- Fuc alpha 1-6)GlcNAc. The glucosylated oligosaccharides, Glc1Man8GlcNAc2 and Glc1Man7GlcNAc2, have not previously been reported in mature glycoproteins from any source.

4-Aminobenzoic Acid↗
PubMed1991

Effect of dichloroacetate on oxidative removal of lactate in mice after supramaximal exercise.

1. The effect of dichloroacetate (DCA), which activates substrate oxidation on oxidative removal of lactate in mice after supramaximal exercise was investigated. 2. DCA significantly decreased the blood lactate concentration and increased the oxidative removal of lactate during prolonged exercise. 3. No significant differences were found in the removal of the blood lactate concentration, in oxidative removal of lactate after supramaximal exercise. 4. It is concluded that DCA administration which activates lactate oxidation during exercise does not activate lactate oxidation in mice after supramaximal exercise.

Animals↗
PubMed1991

Tissue specific expression of the plasma glutathione peroxidase gene in rat kidney.

Rat plasma glutathione peroxidase (GSH-Px) was purified 1,400-fold from rat serum by a combination of phenyl Sepharose, DEAE Sephacel, blue Sepharose and Sephacryl S-200 column chromatographies. The purified GSH-Px migrated as a single band corresponding to a molecular weight of 22,500 on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The enzyme was used for the immunization of chickens to obtain a specific antibody and for determination of its amino acid sequence. Two overlapping cDNA clones for rat plasma GSH-Px were isolated from a placental cDNA library. The composite nucleotide sequence is 1,529 base-pairs long and encodes 226 amino acids. The deduced amino acid sequence completely coincided with the sequences of five individual peptide fragments derived from the purified plasma GSH-Px on digestion with lysyl endopeptidase. In order to identify the tissue(s) generating this plasma GSH-Px, immunoblot analysis was performed on homogenates prepared from 13 tissues. A single immunoreactive band of 22.5 kDa, corresponding to plasma GSH-Px, was detected for the kidney homogenate. A much fainter band was observed for the lung preparation, but liver, spleen, bone marrow, and other tissues examined were negative. Northern blot analysis further revealed that the expression level of the plasma GSH-Px gene was high in kidney and low in lung. No transcript was detected in liver or spleen. These results indicate that plasma GSH-Px is predominantly synthesized and secreted by renal cells.

Amino Acid Sequence↗
PubMed1991

Protection of rats against dental caries by passive immunization with hen-egg-yolk antibody (IgY).

Hen-egg-yolk antibody (IgY) was prepared against Streptococcus mutans MT8148 serotype c that was cultivated in medium containing sucrose, and it was used in passive caries-immunity studies. Specific pathogen-free rats infected with S. mutans MT8148 (c) and fed with a cariogenic diet containing more than 2% immune yolk powder developed significantly lower caries scores than did the ones infected with the same strain and fed with a diet containing only control yolk powder obtained from non-immunized hens. Similar results were obtained in an experiment with rats infected with S. mutans JC-2 (c) strain. Rats provided a diet supplemented with 0.5% immune water-soluble protein fraction containing S. mutans-specific IgY and challenged with S. mutans MT8148 exhibited significantly fewer caries lesions, compared with control rats on the normal diet.

Administration, Oral↗
PubMed1990

Gastroenteritis in suckling mice caused by human rotavirus can be prevented with egg yolk immunoglobulin (IgY) and treated with a protein-bound polysaccharide preparation (PSK).

Oral inoculation of human rotavirus MO strain (serotype 3) into 5-day-old BALB/c mice cause gastroenteritis characterized by diarrhea. Clinical symptoms, histopathological changes in the small intestine, and the detection of rotavirus antigen in enterocytes were all characteristic of rotavirus-induced gastroenteritis. Using this small animal model, passive protection of suckling mice against human rotavirus infection was achieved with the use of immunoglobulin (IgY) from the yolks of eggs of rotavirus-immunized hens. When IgY against a rotavirus strain homotypic to the challenge virus (MO strain) was administered in the mice, complete protection against rotavirus infection was achieved. On the other hand, with oral administration of IgY against a heterotypic strain (serotype 1, Wa strain), a lower protective effect was nevertheless obtained. The four different strains of human rotavirus (Wa, KUN, MO, and ST3) were inactivated in vitro by treatment with PSK, a protein-bound polysaccharide preparation, in a dose-dependent manner. Oral administration of 2.5 mg of PSK caused a therapeutic effect on experimentally MO-infected suckling mice. The antiviral effect of PSK was indicated by the reduction of the duration of diarrhea.

Animals↗