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Biomedical subjects

H W Kwan

Publications and source records attributed to H W Kwan.

At least 19 recordsLinked to original sources
PubMed2001

Oral administration of milk from cows immunized with human intestinal bacteria leads to significant improvements of symptoms and signs in patients with oral submucous fibrosis.

BACKGROUND: Previous studies have shown that the local and systemic upregulation of fibrogenic cytokines and downregulation of antifibrotic cytokine are central to the pathogenesis of oral submucous fibrosis (OSF). The milk from cows immunized with human intestinal bacteria (immune milk) contains an anti-inflammatory component that may suppress the inflammatory reaction and modulate cytokine production. Therefore, it was decided to test whether immune milk may have some beneficial effects on controlling the symptoms and signs in OSF patients. METHODS: In this preliminary study, 26 OSF patients who received immune milk treatment (45 g of immune milk powder twice a day) for 3 months and oral habit intervention were included in the experimental group. Another 20 OSF patients who received only oral habit intervention served as the control group. RESULTS: We found that the interincisor distance was significantly improved (> or =3 mm of the baseline measurement) in 18 of the 26 (69.2%) OSF patients in the experimental group at exit. However, in the control group none of the OSF patients had an increase in interincisor distance greater than 2 mm. In addition, disappearance or significant improvement of symptoms at exit was observed in 80% (16/20) of the patients with intolerance to spicy foods (P < 0.001) and 72.2% (13/18) of the patients with xerostomia (P < 0.005) in the experimental group, compared with 17.6% (3/17) of the patients with improvement of intolerance to spicy foods and 15.4% (2/13) of the patients with improvement of xerostomia in the control group. Partial regression of concomitant oral leukoplakia or erythroplakia (judged from the size reduction of the lesions) at exit was noted in 71.4% (5/7) of the patients in the experimental group (P < 0.05), compared with none (0/5) of the patients with improvement in the control group. CONCLUSION: We conclude that oral administration of immune milk leads to significant improvements of symptoms and signs in OSF patients.

Adult↗
PubMed2000

Effects of continuous calcitonin treatment on osteoclasts derived from cocultures of mouse marrow stromal and spleen cells.

BACKGROUND: Continuous calcitonin (CT) treatment for bone diseases associated with increased bone resorption may be followed by prolonged depression of osteoclast response to CT. The mechanisms of this "escape" phenomenon remain unclear. METHODS: We examined the effects of continuous CT treatment on cell formation, calcitonin receptor (CTR) expression, response to CT, and bone resorption of osteoclasts in a coculture of mouse marrow stromal and spleen cells in the presence of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3]. Cells were cocultured and treated with salmon CT (sCT) for 7, 14, or 21 days. The effects of continuous CT treatment on osteoclast formation was determined by quantitation of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells (MNCs). CTR expression in osteoclasts was determined by binding of [125I]sCT in autoradiography. Bone resorption and CT responsiveness were assessed by examining the formation of resorption pits and by enumerating osteoclast reattachment on dentine slices after sCT rechallenge. RESULTS: TRAP-positive MNCs appeared in cocultures treated with sCT and were similar in number and morphology to those in control cultures, regardless of the concentration and duration of sCT treatment. A decrease in CTR expression was identified as a loss of silver grains from the TRAP-positive cells in cocultures receiving sCT treatment for 14 or 21 days. Partial recovery of CTR expression in TRAP-positive cells was evident in cocultures treated with sCT for only the first 7 days of coculture. TRAP-positive MNCs in cocultures treated with sCT for 14 or 21 days were resistant to the rechallenge with sCT. They attached to dentine slices and caused numerous resorption pits compared with control cells and cells treated with sCT for the first 7 days of coculture (p < 0.01). CONCLUSION: These findings suggest that the escape phenomenon that develops after continuous CT treatment may be due, at least in part to: 1) loss of responsiveness to CT in existing osteoclasts; and 2) development of new osteoclasts that are CTR-deficient and, therefore, refractory to CT rechallenge.

Animals↗
PubMed1996

Fear of injections and report of negative dentist behavior among Caucasian American and Taiwanese adults from dental school clinics.

Fear of injections and reports of negative dentist behavior and associations with dental anxiety and avoidance of treatment were explored among 951 adults from dental school clinics in Iowa City, Iowa and Taipei, Taiwan. Use and fear of anesthetic injections and negative dentist behavior were assessed by written questionnaire to test associations with demographics, overall dental anxiety (Dental Anxiety Scale or "DAS") and utilization behaviors. Frequency and logistic regression analyses showed that use of dental anesthetics for routine treatment was much greater overall among caucasian Americans than Taiwanese, as was fear of injections. Taiwanese and Americans with high dental anxiety (DAS 12) had similar high fear of injections, but inspite of similar fears about dental drilling, high anxiety Taiwanese reported using much less local anesthesia for routine treatments than did high anxiety Americans. Report of condescending remarks to patients ("put downs") by dentists was mainly an American phenomenon associated with high dental anxiety. Avoidance of appointment making was high for persons afraid of injections and for Americans reporting negative dentist behavior. Avoidance was highest in subjects with high dental anxiety. That predominant characteristics or etiologies of dental anxiety can differ by cultural differences in dental health care systems, dentist beliefs and/or expectations of patients within those systems was discussed in relation to the literature.

Adolescent↗
PubMed1993

Analysis of a DNA polymorphic region in the gtfB and gtfC genes of Streptococcus mutans.

We have previously demonstrated the existence of DNA polymorphisms at the 5' coding regions of the gtfB and gtfC genes specifying the streptococcal glucosyltransferases (J.S. Chia, T.Y. Hsu, L.J. Teng, J.Y. Chen, L.J. Hahn, and C.S. Yang, Infect. Immun. 59:1656-1660, 1991). DNA sequence analysis by polymerase chain reaction and direct sequencing revealed that while several nucleotide changes were identified, accounting for the polymorphisms, the amino acids which they code for remain unchanged. The polymorphic region is located in a highly conserved amino terminus of the glucosyltransferases. A peptide of 19 amino acids from this region reversed the inhibiting activity of an antiserum raised against the proteins coded for by the gtfB and gtfC genes. The results suggest that the polymorphic region, varying in DNA but not in amino acid sequences, might specify some biological function.

Amino Acid Sequence↗
PubMed1989

[Prevalence of temporomandibular disorder syndrome (TMD) in university students--a third year report of the epidemiological study in Taiwan].

A total of 2033 university students (1161 boys, 872 girls, ages ranged from 17 to 32 years) were examined according to an examination form. Pain and functional disorders of the head and neck muscles and TM joints, as well as the dental occlusal conditions were recorded. Questionnaires relating to personal history, oral habits, experience of pain and disorder, and psychoemotional status were also given and replied. It was found that 42.9% of the students had one or more signs of TMD, and girls suffered slightly more often. The prevalence was not as high as in junior college students, and was about the same as in teenagers reported in the previous two years. Occlusal factors like slide in centric, balancing side contact, dental restoration and molar guidance during protrusion were more often found in the TMD group, while missing teeth, incisal overlap, attrition and cross bite were not. About 34% of the students had a previous experience of TM joint pain and/or clicking while only 20% of them had such symptoms during the examination. More than 60% of the students having joint clicking were not aware of this symptom. The oral habit and bruxism were not found to be more often in the TMD group. Emotional factors such as Type A personality, emotion, stress, anger, etc. had a higher score in the TMD group while tension, anxiety, and competition did not. It could be concluded that TMD is a fairly common syndrome in the youth of Taiwan although not serious or treatment demanded. Psychoemotional factors are as important as dental factors in relation to the TMD symptomatology, if not more important.

Adolescent↗
PubMed1988

Subsets of T lymphocytes in peripheral blood of patients with oral lichen planus.

The T lymphocyte subsets in the peripheral blood were studied in 26 patients with oral lichen planus and in 11 normal controls. Lymphocyte subsets were identified with monoclonal antibodies (Ortho Diagnostic System Inc. Raritan, New Jersey, USA) by an indirect immunofluorescent antibody method. This study shows no significant difference between patients with oral lichen planus and healthy controls. The conclusion is that local immunity, due to the breakdown of skin-associated lymphoid tissue, not a generalized immunologic disorder, is considered to be involved in the pathogenesis of oral lichen planus.

Adult↗
PubMed1987

Peripheral ameloblastoma with metastasis.

Peripheral ameloblastoma is an uncommon clinical entity, while ameloblastoma with distant metastasis is still more unusual. A case of peripheral ameloblastoma with left supraclavicular lymph node metastasis is presented here.

Aged↗
PubMed1987

Treatment of a patient with Papillon-Lefèvre syndrome. A case report.

A vital root submersion procedure was performed in a rare case of Papillon-Lefèvre syndrome (PLS). Although the etiology and pathogenesis are obscure, possible host genetic defects and known or unknown periodontal pathogens may play important roles in the progression of PLS. Since this patient did not respond to conventional periodontal therapy, a submersion procedure was employed to maintain the alveolar ridge and resulted in controlling the progression of the patient's severe periodontitis. The following is a report of the treatment and the rationale for therapy.

Alveoloplasty↗
PubMed1987

Preparation of large temporomandibular joint specimens for pathological study.

Ten fresh temporomandibular joint (TMJ) specimens about 5 X 4.5 X 3.5 cm in size were removed at autopsy by 5 cuts according to appropriate anatomical landmarks. After routine formalin fixation, the whole-TMJ specimens were wrapped with a thin layer of self-curing resin and then cut with a low speed bone saw along the parasagittal plane predetermined by x-ray guidance. Each specimen was serially cut into 4 to 5 parallel slices of 3 mm thickness, which were then decalcified with 14% EDTA and embedded in paraffin. Histological sections of 5 microns were stained with hematoxylin and eosin. The procedures were accomplished within 20 to 24 days after autopsy. With this technique, the anatomical interrelationships among the various joint components could be maintained and the macroscopic and microscopic topography of the TMJ could be studied in the desired reference plane. Therefore, the corresponding changes among the joint components in a diseased TMJ could be thoroughly examined. This technique was also applicable for the study of large specimens containing both hard and soft tissues.

Adolescent↗
PubMed1987

Lymphocyte function in patients with recurrent aphthous ulcers.

Lymphocyte proliferation (LP) responses to mitogens: phytohemagglutinin (PHA), concanavalin A (ConA) and pokeweed mitogens (PWM) were studied in 17 patients with recurrent aphthous ulcers (RAU) of minor type (MiAU) and 20 age/sex-matched healthy subjects. RAU patients elicited normal T-cell and B-cell responses to mitogens in comparison with healthy subjects. Proliferative responses were neither enhanced during active episodes of oral ulceration nor suppressed during periods of remission. It seems unlikely that non-specific lymphocyte dysfunction plays a major role in the pathogenesis of RAU.

Adult↗
PubMed1986

Slicing technique for tooth specimens in histological preparation.

A slicing technique for the preparation of a tooth specimen is described. A low speed saw (ISOMET) was used for this modified technique. It is a slicing machine fitted with a diamond-impregnated cutting disc of 0.5 mm in thickness. The formalin was used for lubrication to serve as both a coolant and a fixative simultaneously. It is thought that the preparation will not damage or disturb the surface of the tooth specimen by careful management under 200 rpm with a loading of 50 grams. The cutting of slices can be controlled by adjusting the specimen arm with a micrometer to the desired thickness. A high quality histological preparation can be obtained when the specimen is sliced as mentioned above soon after it is removed from the living body before decalcification. By the observation of specimens such as the resected jaw bone or other large hard tissue specimens, it is suggested that the sliced specimens of 2 mm in thickness can be obtained routinely for histological study by using this method.

Animals↗
PubMed1986

Serum immunoglobulins, complements and circulating immune complexes in oral lichen planus.

Serum IgG, IgM, IgA, C3, C4 concentrations and circulating immune complexes (CIC) were measured in a series of 46 patients with oral lichen planus (LP). This investigation revealed a significant increase in the level of serum IgG in patients with oral LP as compared with 36 healthy subjects. In erosive LP, serum IgM was also elevated as compared with healthy subjects and patients with the non-erosive type. The results of this study did not support the suggestion that a humoral immunodeficiency underlies oral LP. Elevated serum level of IgM may be considered to represent secondary oral infection during mucosal erosion. The study also demonstrated a significant reduction in serum C4 in both variants of oral LP, but the C3 level was normal. A 3% polyethylene glycol precipitation (PEG-ppt) method was used, no significant amount of CIC could be detected in the patients. It is tempting to speculate that oral LP reflects an immunologic disorder in which serum IgG and C4 is disturbed. However, further investigation is needed to clarify the pathogenesis of oral LP.

Adult↗