Awareness Survey on Community Water Fluoridation by Region / 치위생과학회지

Background@#The purpose of this study is to investigate the pro-con of re-implementation by administrative areas and the difference in perception of community water fluoridation in implemented and non-implemented areas after the community water fluoridation in Korea was suspended. Through this, we intend to provide basic data that can help find ways to increase the support and interest of local residents. @*Methods@#The 601 questionnaires collected through the survey and statistical analysis was conducted using SPSS Statistics 28.0. @*Results@#As a result of analyzing the perception of the community water fluoridation according to the understanding of fluorine, the proportion of people who were not recognized by both fluorine and community water fluoridation was the highest (p＜0.05). As a result of the analysis of the pro-con of re-implementation of community water fluoridation, the approval was high. Among those who responded in favor, the place of re-implementation showed that ‘implementation nationwide’ was high. As for the reason for favor, it was found that it was possible to prevent dental caries disease. The reason for the objection was the lack of knowledge about fluoride. @*Conclusion@#The results of the survey for the pro-con of the re-implementation of community water fluoridation showed a higher degree of ‘agree’ and showed that people in the area where community water fluoridation was not implemented showed higher interest in oral health prevention and management. Through this, not only oral education, but also correct information on the implementation method of community water fluoridation, the benefits of community water fluoridation, and the facts that were misunderstood in the past, as well as oral education, can be provided to raise interest in community water fluoridation. It is thought that the expected effect of the re-implementation of community water fluoridation can be obtained if such activities are carried out.

Study on the characterization, biocompatibility and efficacy of sponge brush products for oral care / 대한치과재료학회지

A sponge brush is an oral hygiene product that is used to clean buccal, gingival and palatal mucosa. The aim of this study was to observe the appearance, porosity, water sorption, cytotoxicity and efficacy of sponge brush products. Seven commercially available sponge brush products were used as test materials. To observe the appearance of sponge brush, the dimension and weight were examined. The porosity was measured using the micro CT. The water sorption rate was calculated by weight change before and after immersion of sponge brush in distilled water for 5 s. The sponge brush was extracted according to the KS P ISO 10993-12, and examined the extracted solution by visual inspection. Extracted solution was then evaluated with MTT assay. Protein removal efficacy of sponge brush product from the bovine serum albumin coated sheet was tested using bicinchoninic acid assay. The results of the length and diameter range of brush were 17~24 mm and 14~24 mm respectively.The length and thickness range of the handle was 14~16 cm and 3~5 mm respectively. There were significant differences in the sponge brush weight of all products (p<0.05), and porosity of the sponge was indicated to be more than 80% in all products.The water sorption rate ranged from 21 to 62% (p<0.05). As the results of extraction, there were neither foreign materials nor impurities in all of sponge brush products. The cell viability was indicated to be more than 70% except for two products.After applying all sponge brush products, the protein removal rate was more than 70%. The above results will provide useful information for future development of related oral care products.

Study on the characterization, biocompatibility and efficacy of sponge brush products for oral care / 대한치과재료학회지

A sponge brush is an oral hygiene product that is used to clean buccal, gingival and palatal mucosa. The aim of this study was to observe the appearance, porosity, water sorption, cytotoxicity and efficacy of sponge brush products. Seven commercially available sponge brush products were used as test materials. To observe the appearance of sponge brush, the dimension and weight were examined. The porosity was measured using the micro CT. The water sorption rate was calculated by weight change before and after immersion of sponge brush in distilled water for 5 s. The sponge brush was extracted according to the KS P ISO 10993-12, and examined the extracted solution by visual inspection. Extracted solution was then evaluated with MTT assay. Protein removal efficacy of sponge brush product from the bovine serum albumin coated sheet was tested using bicinchoninic acid assay. The results of the length and diameter range of brush were 17~24 mm and 14~24 mm respectively.The length and thickness range of the handle was 14~16 cm and 3~5 mm respectively. There were significant differences in the sponge brush weight of all products (p<0.05), and porosity of the sponge was indicated to be more than 80% in all products.The water sorption rate ranged from 21 to 62% (p<0.05). As the results of extraction, there were neither foreign materials nor impurities in all of sponge brush products. The cell viability was indicated to be more than 70% except for two products.After applying all sponge brush products, the protein removal rate was more than 70%. The above results will provide useful information for future development of related oral care products.

The Past and Current Status of Dentists in Japan / 치위생과학회지

The purpose of this study is to provide the general history of fostering dentists in Japan and introducing their new roles. This research was conducted based on the government policy report on dentists and the information published by each educational institution. Based on the collected data, the official websites were used to represent the latest statistics of the institutions. The number of dentists in Japan has increased. The government established the National Examination for Dentists to guarantee the quality of dentists. After the standards for developing questions for the national examination were established in 1985, the contents of the examination have been appropriately improved by revising the standards every four years. This improvement has required dental students to study a variety of subjects for six years at dental school. Since dentists in Japan are required to respond to various demands from the nation; the Model Core Curriculum for Dental Education was developed to teach medical ethics and abilities to ensure that dentists conduct themselves professionally. Recently, the roles of dentists have been changing in Japan.When providing dental services to older patients over the age of 65, dentists and other dental professions focus on maintaining oral functions, such as saliva secretion, bite force, tongue movement, and masticatory/swallowing functions. However, oral function-related services for children are different. In addition to providing essential dental services, dental practitioners also provide special treatment, such as oral muscle training, myofunctional therapy, health guidance, and space retainers to the child patients with developmental insufficiency in oral functions. Dentistry in Japan has undergone numerous changes over the years and has continued to offer high-quality dental health services. Thus, information gained from the Japanese experience may be helpful to dental professions in other developed countries for planning oral health measures.

Status of Oral Care according to the Type of Surgery for Inpatients at Dental Hospitals / 치위생과학회지

Background@#The aim of this study was to understand the importance of professional oral care for inpatients by examining the type and frequency of surgery and hospital discharge period at dental hospitals, and identify the types of professional oral care actually in progress. @*Methods@#In this study, the type of surgery and length of hospitalization were investigated among patients admitted to the dental hospital for oral and maxillofacial surgery, and the professional oral care status of inpatients who had difficulty self-managing their oral care was retrospectively identified by collecting data on oral care before and after surgery, including the type and frequency. @*Results@#The majority of inpatients at dental hospitals were male (57.6%), elderly patients over 60 years accounted for 20% of patients, and the average length of hospitalization was 4 days. In the 20s (aged 20∼29 y), the number of orthognathic surgery patients (73.1%) was high, and the incidence of cysts was high in middle-aged patients. Regarding the oral care of hospitalized patients, scaling was performed once by a dentist before surgery. After surgery, surgical dressings using H2O2 balls were applied and oral care education was introduced before discharge. @*Conclusion@#Based on the results of this study, professional oral care is essential to prevent infection and complications caused by oral bacteria among inpatients at dental hospitals. It is necessary to use various oral hygiene aids for inpatients and to conduct effective oral care instruction according to each patient’s situation. In addition, it is necessary to raise awareness and the role of dental hygienists in professional oral care.

Relevance between Marketing Route of Social Media and Consumer Age Group for Choosing Dental Clinics / 치위생과학회지

Background@#The purpose of the study was to evaluate the relationship and route of dental Social Media marketing by age group and support effective dental marketingy by age group. @*Methods@#A study was conducted on 265 people, aged 20 to 64 years, who lived in Seoul, Gyeonggi area and regularly used one or more of the social media platforms, Naver Band, Facebook, Instagram, KakaoStory, Twitter, or YouTube more than once a day. A 27-question questionnaire survey of approximately 10 minutes was conducted, and the collected data was statistically analyzed using the PASW program, with the significane level set to 0.05. @*Results@#“Introduction of acquaintances” was the most common route to visit the dentist. Regarding the use of social media platforms based on age group, ‘Instagram’ had the highest frequency among people belonging to the age groups of 20 to 29 years and 30 to 39 years; ‘YouTube’ had the highest frequency among those aged 40 to 49 years; and ‘Naver Band’ had the highest frequency among those aged 50 to 65 years. @*Conclusion@#The most frequently used social media by consumers according to age included Facebook, YouTube, and Instagram. However, social media was found to have no significant impact on the choice of dental institutions, as the number of people who visited the dentist through “Introduction of acquaintances” was the highest, and “Introduction of acquaintances” did not have experience accessing the dentist site after dental marketing. If this study could provide customized marketing information for each age group through social media, it is expected that the marketing effect of dental institutions through social media would be maximized in the future.

Suggestions for the Work of Dental Hygienists and a Reflection of Health Insurance Charges according to Demographic Changes / 치위생과학회지

Given that the demand for dental care for elderly individuals is expected to increase according to demographic changes, long-term roadmaps for the current health insurance system should be actively planned. The study aimed to investigate the health insurance system in Korea, compared to that of Japan, and suggest directions for the work of dental hygienists to provide basic data on efficient improvements in the health insurance system. Based on the collected data, the website was used to collect additional related data from Korea and Japan. The most common cause of death in Korea was malignant neoplasms, and most patients were hospitalized for diseases and disorders of the musculoskeletal system and connective tissue. Dental care covered by Korean medical insurance for individuals aged 65 years or older was treatment oriented, such as dentures and implants, while in Japan, treatment-intensive items, such as visiting a dental hygienist for guidance and provision of home-care professional oral hygiene treatment, were covered. The percentages of remaining teeth in Korea and the percentage of remaining 20 teeth were 68.9% in those aged 65 to 74 years and 51.2% in those aged 75 to 84 years in Japan. A strategy for promoting oral health among elderly individuals should be established, and a multilateral intervention approach is required to prevent oral problems from leading to deterioration of whole-body health. The role of dental hygienists in providing comprehensive assessment to elderly individuals is important. In order to provide systemic oral care, it is necessary to introduce oral care systems according to the national policy.

Dental Hygienists in Japan / 치위생과학회지

The purpose of this study was to determine the status of dental hygienists in Japan. The study explicated the history, core curriculum, National Examination for Dental Hygienists, work roles of dental hygienists, and workplaces of dental hygienists. This study was based on the government policy report on dental hygienists and the information published by each public institution. The latest statistics presented by the institutions were collected through official websites. The employment information of graduates from Hiroshima University was analyzed based on actual field study. The results of the study revealed that social demand for dental hygienists has steadily increased and policies and education have been revised accordingly. The work roles of dental hygienists have expanded to meet the needs of the treatment and those of public health fields. In line with major policy changes, the educational period has been extended from 1 year to 3 or 4 years, while the mandatory credits for graduation have been established. Licensing examinations were being performed by the local governments since 1948 due to the different situations of dental hygienists in different areas. In 1992, they were converted into a single national examination. The work roles have expanded from assisting dental treatments to health guidance, home care, and perioperative care. Consequently, the number of dental hygienists has increased, especially in healthcare facilities for the elderly. Dental hygienists perform various roles. However, the most essential role is to provide the best oral care services to the patient. The expected role of dental hygienists has expanded in alignment with public healthcare needs and support for the elderly. The government and universities are expected to bring about improvements such as diversifying the channels of education and establishing policies to respond to growing patient needs by cultivating excellent dental hygiene professionals.

The effect of general health status, oral health behavior and status on quality of life in Korea adults / 대한구강보건학회지

Objectives@#The purpose of this study was to analyze the relations between general health status, oral health behavior, oral health status, and quality of life, as well as the mediating effects of oral health behavior and oral health status. @*Methods@#Subjects aged ≥19 years participated in a health questionnaire in the third year of the Japanese National Health and Nutrition Examination Survey (2015). @*Results@#Analysis of the overall path of periodontal disease showed that respiratory and circulatory diseases and oral health behaviors had statistically significant indirect effects on quality of life through the mediation of oral health behavior and oral health conditions, while analysis of the overall trend of the decayed, missing, and filled teeth (DMFT) index showed significant indirect effects on quality of life through mediation between oral and oral health conditions. As a result of these analyses, the association of general health status with quality of life, and its effect thereon, were confirmed through the intermediary of oral health behaviors and oral health conditions. @*Conclusions@#Therefore, further research is needed on the relation of general diseases to oral health management. Special oral health departments need to be established in both general and university hospitals, and dental hygienists in charge of oral care need to be deployed to improve oral health for general diseases. Manuals and systems for oral health management and oral health promotion need to be developed for certified dental hygienists in Japan, specifically for each systemic disease. For example, hygienists should have guidance on the oral health practices that help in the prevention of diabetes.

Elderly Welfare System and Role of Dental Hygienists in Korea and Japan / 치위생과학회지

In accordance with the aged society, oral health care for the elderly is considered important to maintain general health. Although the role of dental hygienists is essential for proper health management of the oral cavity, research on the care system for the elderly people's oral health and on the role of dental hygienists in the field of elderly welfare is still insufficient. Hence, the aim of this study is to investigate the status of Korean elderly welfare system and dental hygienists by comparing them with those in Japan, a precedent of aged society. First, we compared and investigated the Japanese long-term insurance system, which provides an institutional basis for a long-term care system for the elderly in Korea. Second, the elderly welfare law and care system, focusing on oral care, were examined. Lastly, in elderly care, we analyzed the distinctions between Korea and Japan regarding dental hygienists' role and scope of work. Taken together, as a precedent of aged society, Japan has shown well-specialized and systematic welfare for the elderly compared with Korea. With the development of the welfare system for the elderly in Japan, the role and the workscope of dental hygienists have been expanded to improve quality of life of elderly people, as a key professional for elderly oral care. Therefore, we should perceive the need for improvement of long-term care insurance and the expansion of dental hygienists' work in Korea. In conclusion, these results could be used as basic data for improving the elderly welfare system and developing dental hygienists in Korea.

Hydrogen peroxide inhibits Ca²⁺ efflux through plasma membrane Ca²⁺-ATPase in mouse parotid acinar cells

Intracellular Ca²⁺ mobilization is closely linked with the initiation of salivary secretion in parotid acinar cells. Reactive oxygen species (ROS) are known to be related to a variety of oxidative stress-induced cellular disorders and believed to be involved in salivary impairments. In this study, we investigated the underlying mechanism of hydrogen peroxide (H₂O₂) on cytosolic Ca²⁺ accumulation in mouse parotid acinar cells. Intracellular Ca²⁺ levels were slowly elevated when 1 mM H₂O₂ was perfused in the presence of normal extracellular Ca²⁺. In a Ca²⁺-free medium, 1 mM H₂O₂ still enhanced the intracellular Ca²⁺ level. Ca²⁺ entry tested using manganese quenching technique was not affected by perfusion of 1 mM H₂O₂. On the other hand, 10 mM H₂O₂ induced more rapid Ca²⁺ accumulation and facilitated Ca²⁺ entry from extracellular fluid. Ca²⁺ refill into intracellular Ca²⁺ store and inositol 1,4,5-trisphosphate (1 µM)-induced Ca²⁺ release from Ca²⁺ store was not affected by 1 mM H₂O₂ in permeabilized cells. Ca²⁺ efflux through plasma membrane Ca²⁺-ATPase (PMCA) was markedly blocked by 1 mM H₂O₂ in thapsigargin-treated intact acinar cells. Antioxidants, either catalase or dithiothreitol, completely protected H₂O₂-induced Ca²⁺ accumulation through PMCA inactivation. From the above results, we suggest that excessive production of H₂O₂ under pathological conditions may lead to cytosolic Ca²⁺ accumulation and that the primary mechanism of H₂O₂-induced Ca²⁺ accumulation is likely to inhibit Ca²⁺ efflux through PMCA rather than mobilize Ca²⁺ ions from extracellular medium or intracellular stores in mouse parotid acinar cells.

Effect of p-Dimethylaminoazobenzene and 2(3)-tert-Butyl-4-hydroxyanisole on Lipid Pcroxidation, Glutathione-S-transferase, Peroxidase and Reductase in Rat Liver

An experiment was conducted in order to investigate the effect of p-dimethylaminoazobenzene (DAB) and 2(3)-tert-butyl-4-hydroxyanisole (BHA) on the lipid peroxidation and peroxide-destroying enzyme system in the rat liver. Dietary supplementation of DAB (0.06%) for three weeks caused the elevation of glutathione-S-transferase activity by 60% and glutathione reductase by 50%, but it decreased glutathione peroxidase and catalase activities significantly. Dietary supplementation of BHA (0.75%) also increased glutatione-S-transferase activity in the liver by 2 folds, and it counteracts DAB effect on the glutathione peroxidase and catalase activities. There was a marked increase in malon-dialdehyde content in the postnuclear fraction of liver by the treatment of DAB, but the addition of BHA lowered the malondialdehyde content to almost the control level. The protective effect of BHA on the lipid peroxidation induced by DAB administration at the enzyme level seems to be due to the induction of glutathione-S-transferase and the protection of glutathione peroxidase and catalase activities from being lowered by DAB administration.

Interaction between Inorganic Mercury and Selenium on Tissue Sulfhydryl Groups and Glutathione-linked Enzymes in Rats

The effect of selenium on the tissue sulfhydryl group content and lipid peroxide-destorying enzyme system in the liver, kidney and testis of rat treated with mercury was investigated. The male rats were injected s.c. with HgCl2 (10 micromoles/kg BW) and orally received Na2SeO3 (13 micromoles/kg BW) simultaneously. After 3 days, liver, kidney and testis were removed and analyzed. Mercury decreased the total sulfhydryl group content in the kidney by 25% and the total glutathione content in the kidney and testis by 50% and 36%, respectively, with no changes in other tissues. There was 12% increase in the total sulfhydryl group but not in the total glutathione content in kidney by a simul-taneous treatment of Se and Hg. Glutathione peroxidase (GSH-Px) activities were decreased by 63% in the liver and 69% in the kidney, and glutathione reductase (GSH-Rd) activity was increased in the tests by 16% by the Hg treatment with no changes in Other tissues. Hg had no effect upon glutathione-S-transferase activities in all organs examined. Simultaneous Se treatment increased GSH-Rd activity in the kidney by 23% and GSH-Px activities in liver and kidney by 24% and 21%, respectively, compared to the Hg-treated group. These data indicate that the alleviation of Hg toxicity by Se treatment is well correlated with the protein sulfhydryl group content and GSH-Px activity.

Properties of Hepatitis B Virus Associated DNA Polymerase

The nature of hepatitis B virus (HBV) particle associated DNA polymerase was studied in relation to various enzyme inhibitors including antiviral agents. HBV DNA polymerase required high concentration of MgCl2(> 30 mM) and neutral pH for its full activity. p-chloromercuribenzoate was a strong inhibitor (85% inhibition at 1 mM) but N-ethylmaleimide had much less inhibitory effect (20% inhibition at 10 mM). Phosphonoformic acid showed the greatest inhibitory effect on HBV-DNA polymerase (almost complete inhibition at 100 microM) among phosphocompounds tested. Adenine arabinoside triphosphate (ara-ATP) and cytosine arabinoside triphosphate (ara-CTP) were competitive inhibitors with respect to their respective deoxyribonucleoside triphosphate (dATP and dCTP). Ara-CPT was a stronger inhibitor of HBV-DNA polymerase compared to ara-ATP. Ki values for ara-ATP and ara-CTP were 15.0 microM and 11.7 microM , respectively. HBV-DNA polymerase is characteristic in its ionic requirements and susceptibilities to certain inhibitors.

Effect of Dexamethasone and Epinephrine on Metallothionein Level in the Perfused Rat Liver

The effect of dexamethasone (10(-5)M) and epinephrine (10(-6)M) on the biosynthesis of metallothionein (MT) in the perfused rat liver was investigated. MT synthesis was determined by measuring the incorporation of 14C-L-aspartic acid into liver MT fraction after the perfusion for five hours of isolated liver by artificial blood containing 14C-L-U-aspartic acid (0.2uci) with dexamethasone or epinephrine. MT was isolated by Sephadex G-75 column chromatography and DEAE Sephadex column chromatography. Incorporation of radioactive 14C into the MT fraction of perfused liver cytosol (9.0grams of liver) from dexamethasone treated, epinephrine treated and control groups were, respective1y, 0.72, 0.34 and 0.33% of total radioactivity infused. Total protein content in the MT fraction of liver perfused with dexamethasone and epinephrine were 0.80, 0.64mg/g liver compared to 0.52mg/g liver in the control. MT, a protein having a high content of cystein and metals is synthesized in the perfused rat liver and its induction is stimulated by dexamethasone, while epinephrine increased the accumulation of Zn in the MT fraction of the perfused rat liver. The present experiment confirms that MT synthesis and degradation are somewhat regulated by glucocorticoid hormone and epinephrine.

Effect of Antioxidants on the Incidence of 7, 12-dimethylbenzanthracene-induced Mammary Tumor in Rats

The inhibitory effect of selenium, vitamin E, and BHA on DMBA-induced mammary tumorigenesis in rats was investigated. Dietary vitamin E (200 IU/Kg diet) alone could not reduce the tumor incidence at 25 weeks after DMBA administration (10mg DMBA/rat) when selenium was deficient. Selenium supplementation (2ppm in drinking water) to rats fed a practical diet (0.17 ppm Se) reduced the tumor incidence to 14.3% from 75% at 27 weeks after DMBA administration. Dietary supplementation of BHA (0.75%) also reduced the incidence of DMBA-induced mammary tumor to 42.9% at 27 weeks after DMBA-treatment. Rats fed a diet deficient in both selenium and vitamin E contained significantly lower glutathione peroxidase activity and higher malondialdehyde in muscle. However, supplementation of selenium or BHA to the rats fed a practical diet did not alter the malondialdehyde content and glutathione peroxidase activities in muscle, skin and mammary gland. Dietary selenium increased the tissue selenium level. DMBA-induced mammary tumorigenesis was reduced by antioxidants tested but the anticarcinogenic effect of selenium or BHA seems to be independent of glutathione peroxi-dase activity.

Purification of r-Glutamyltranspeptidase from Rat Primary Hepatoma Tissue and Preparation of a Tumor Associated Antigen

r-Glutamyltranspeptidase (r-GT) from a rat hepatoma induced by 3'-methyl-4-dimethylaminoazobenzene (3'-Me DAB) was purified 833 fold. The purified enzyme had a specific activity of 15.0 U/mg protein with an overall yield of 3.8%. The molecular weight of native r-GT was estimated as about 350,000 daltons, whichs a multicomplex of a single polypetide having a M W of 59,000. Anti r-GT rabbit antiserum cross-reacted with kidney r-GT as well as liver r-GT. Tryptic digestion of r-GT followed by separation with Con A sepharose column chromatography resulted in two major glycopeptides. A tumor associated antigen was prepared by the conjugation of a tryptic glycopeptide of r-GT to keyhole limpets hemocyanin and an antibody against this antigen cross-reacted preferentially with r-GT in rat hepatoma tissue.

Inhibition of HBV replication by antisense oligodeoxyribonucleotides in HepG2 cells transfected with a cloned HBV DNA

The effect of antisense oligodeoxyribonucleotides(oligo[dN]s) on hepatitis B virus(HBV) replication in HepG2 cells harboring a cloned HBV genome was examined. Antisense oligo(dN)s directed at translational initiation sites of S, pre C and P genes of HBV were treated to the cells and the amount of HBsAg and HBV DNA content were measured 72 hours after the treatment. HBsAg expressions in HepG2 cells harboring the HBV genome were inhibited 68%, 53%, and 46% by the treatment with antisense oligo[dN] directed at S, pre C, and P gene loci, respectively, and HBV DNA content in the cells was also reduced by the treatment of each antisense oligo[dN]. The doubling times of the cultured cells treated with 25 micrograms, 50 micrograms, and 100 micrograms of antisense oligo[dN]/ml medium were 43.3, 62.1, and 93.0 hours, respectively, compared with 37.5 hours of the untreated control cells. Cellular DNA synthesis was inhibited by the treatment with 100 micrograms/ml of antisense oligo [dN], however, no significant effect was observed by the treatment with 50 micrograms or less of antisense oligo[dN]/ml. These results suggested that antisense oligo[dN]s specific to the translational initiation sites of S, pre C, and P genes of HBV may have therapeutic potential for the suppression of HBV propagation in chronic HBV infected patients.

Identification of major allergens from the house dust mites, Dermatophagoides farinae and Dermatophagoides pteronyssinus, by electroblotting

The allergens were separated from the extracts of house dust mites by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and identified by autoradiography. Over 30 protein bands of the whole body extract of Dermatophagoides farinae were apparent on 10-20% gradient SDS-PAGE, and 13 bands with MW between 93KD and 12KD bound with specific IgE antibodies in patients' sera sensitive to house dust mites. The major allergenic component of the whole body extract of D. farinae was the protein of MW 14-15KD, which was detected in 95.7% of 47 patients' sera sensitive to house dust mites. The extract of Dermatophagoides pteronyssinus supplied by Bencard Company, England was thought to contain feces enriched material as noted in a few broad protein bands on SDS-PAGE. Seven allergenic components were shown by autoradiography. The protein band of MW 14-15KD was one of the most frequently revealed allergens on autoradiography, which has appeared in 32.5% of 40 patients' sera sensitive to house dust mites. The electrobotting technique used in the present study was fast, convenient and highly useful for both the identification of allergen components and the screening of specific IgE antibody. The individual variations of IgE immune responses to the allergenic components of the two house dust mites were discussed.

Structure of heavy and light chains of blood coagulation factor VIII (FVIII) involved in the activation of FVIII

Structure of human blood coagulation factor VIII (FVIII) in relation to its activation process was investigated. FVIII was purified from a commercial FVIII concentrate by immunoaffinity chromatography and its dissociated subunits, heavy and light chains were isolated. The light chain (FVIII-L) was treated with thrombin or factor Xa (FXa) in order to cleave the peptide at Aug(1689) or Arg(1721), respectively, Reassociation of FVIII-H with either of FVIII-L derivatives, FVIII-L-72 (72 kDa) and FVIII-L-65 (65 kDa) brought about the formation of heterodimers which have similar cofactor activity. The association constant of FVIII-H with FVIII-L-72 was about two-fold faster than that with FVIII-L-65, Cleavage of major FVIII-H with thrombin generated two peptides with molecular weights of 50 kDa (A(1)) and 40 kDa (A(2)) Formation of heterotrimer by reassociation of A(1), A(2) and FVIII-L-72-generated FVIII cofactor activity, while the dimers formed from A(1) or A(2) with FVIII-L-72 had no activity, suggesting that both A(1) and A(2) are required for FVIII activity, Heterotrimers formed from A(1) and A(2) with either of FVIII-L-72 or FVIII-L-65 in the presence of CaCl2 (10 mM) revealed cofactor activity, and they were dissociated into subunits with the loss of activity when EDTA (10 mM) was added, indicating that the formation of heterotrimer, the functional unit of FVIII, from A1, A(2) and FVIII-L is calcium dependent and that the cleavage of FVIII-L by FXa does not inactivate FVIII.