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Biomedical subjects

Y C Lü

Publications and source records attributed to Y C Lü.

At least 19 recordsLinked to original sources
PubMed1999

[Binding and interaction of histones and transcription factors on the promoter of hAMFR gene].

In this study, histone H1, core histones H2A-H2B and H3-H4 were purified from chicken erythrocytes by hydroxylapatile chromatography. The nuclear extract was prepared from HeLa cells. We investigated the binding and interaction of histones and transcription factors on the upstream sequence of human autocrine motility factor receptor (hAMFR) gene by gel shift mobility assay. We found that the binding of H1 on the promoter sequence of hAMFR gene was relatively stable. We propose that H1 plays an important role in stablizing chromatosome. We also found that histones and HeLa cell extract could form a ternary complex with the DNA template.

Animals↗
PubMed1999

[Effects of the interaction between histone and hAMFR gene promoter on the transcription activity in vitro].

The effects of interaction between histones and human autocrine motility factor receptor (hAMFR) gene promoter on the transcription activity in vitro was investigated by using histones purified from chicken erythrocytes, HeLa cell nuclear extracts and heat-treated supernatants of Xenopus eggs. The results showed that the competitive binding of histones and transcription factors at the promoter of hAMFR gene was very important to the transcription in vitro. If a pre-initiation complex was formed with HeLa cell nuclear extracts on the promoter prior to nucleosome assembly, it would prevent nucleosome-mediated transcription repression. When the nucleosome was assembled on the promoter in advance, the transcription activity could be repressed. When histones and HeLa cell nuclear extracts were mixed in the reaction simultaneously, the transcription activity would depend on the relative amount of histones to that of HeLa cell nuclear extracts.

HeLa Cells↗
PubMed1993

Growth of human melanocytes from suction blister of localized vitiligo patient and from foreskins of newborns and adults by modified culture medium.

We report on the culturing of melanocytes from suction blisters from the uninvolved skin of localized (focal and segmental) vitiligo patients and from the foreskins of newborns and adults, over a long period of time using a modified culture medium composed of F-12 medium supplemented with insulin (5 mg/mL), cholera toxin (40 ng/mL), transferrin (5 mg/mL), hydrocortisone (1 mM), epithelial growth factor (20 ng/mL), endothelial cell growth supplement (ECGS) (15 mg/mL), retinol (1 x 10(-7) M), 12-o-tetradecanoyl-phorbol-13 acetates (TPA) (85 nM), and 1% fetal calf serum (FCS). This method may be used in in vitro studies on normal human melanocytes and for study of the difference between melanocytes of normal individuals and of those with vitiligo. The ability to culture melanocytes from localized vitiligo, and the inability to grow those of generalized vitiligo with this system reconfirms the difference in the pathogenesis of various types of vitiligo. Thus, culturing may be used for differentiating localized vitiligo from generalized vitiligo and may be used to guide the mode of treatment when vitiligo has just started to develop and only a few depigmented patches have appeared. The results of studies on seeding density effect and serial Dopa reaction on the melanocytes of normal individuals reveal that the use of tyrosinase activity as the assessment parameter requires the use of melanocytes cultured for less than five months at a seeding density of less than 4 x 10(4) cells/cm2. Enlarged and heavily pigmented cells, senescent cells, were observed after very long-term culture (one year and four months).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Trichotillomania: a clinical study of 36 patients.

To understand the clinical characteristics of trichotillomania, 36 patients were investigated at the psychocutaneous special clinic from February 1982 to October 1990. There were 16 males and 20 females. The most prominent age was found in a group of 23 (63.9%) elementary school children, and in regards to the age of disease onset, 35 (97.2%) of our patients were under the age of 18. A 30-year-old woman with schizophrenia and a 6-year-old boy with mental retardation were noted in our study; the remaining 34 patients were generally well without signs of mental illness except for the recurrent failure to resist impulses to pull out their own hair. The common life events precipitating stress were academic problems and parent-child conflicts. The duration of follow-up was for at least 6 months. The habit of hair plucking was easily corrected if the duration of the disease was less than 6 months. Usually these patients had a satisfactory regrowth of hair within 1-3 months after our explanation and reassurance. In contrast, the patients with a hair loss of more than half a year were not easy to approach, and needed psychiatric treatment.

Adolescent↗
PubMed1991

Cryofibrinogenemia: report of a case.

Cryofibrinogenemia, a rare disease, is diagnosed by the presence of reversible cryoprecipitate in plasma, which may cause various clinical manifestations of thromboembolic or hemorrhagic disorders. A 66-year-old female patient suffered from recurrent reticulate erythema, purpura and gangrene on the distal portion of the extremities and face during the winter for 5 years. Cryofibrinogenemia was proven with the following evidences: (1) Histopathologic findings revealed many eosinophilic cylinders, about 6-9 microns in diameter, deposited within the lumen of the blood vessels in the dermis and subcutaneous tissue. There was no evidence of vasculitis. These cylinders were fibrinogen in nature, as proven by direct immunofluorescence. (2) Cryofibrinogen was detected in the citrated plasma, which was confirmed by double immunodiffusion, the presence of an IgG-kappa M protein was also revealed by immunofixation. Debridement and skin grafts were performed, and prednisolone combined with cyclophosphamide were given. Skin lesions improved without recurrence, and the "cryocrit" decreased from 13.6% to less than 2% during the follow up. We conclude that if there is any case with the similar cutaneous manifestations, cryofibrinogenemia should be considered.

Aged↗
PubMed1989

The subtypes, distribution and location of human papillomavirus DNA in genital warts and genital Bowen's disease--a study using in situ DNA.DNA hybridization.

The aim of this study is to investigate the difference in subtypes and distribution of human papillomavirus (HPV) between the benign pathological condition- Genital wart (condyloma acuminatum, verruca- like lesion and papular lesion) and genital Bowen's disease (Bowenoid papulosis, Mollucum contagiosum with Bowenoid papulosis and Condyloma acuminatum with verruca- like lesion and pathological bowenoid change) of genitalia by in situ DNA.DNA hybridization. In situ DNA.DNA hybridization was performed by hybridizing the RNAse treated and denatured frozen skin section with 3H-labeled HPV 6, 11, 16 and 18-DNAs probes and then developed autoradiogram on a glass slide. The results reveal that: (1) The benign cases are strongly associated with HPV 6/11, while the bowenoid cases are associated with HPV 16/18, indicating 16 positive in 24 cases and 3 positive in 5 cases respectively; (2) Four of sixteen benign cases were doubly infected with HPV 6/11 and 16/18; and 2 of 2 bowenoid cases were infected with HPV 16/18 only (3) In benign cases, HPV distributes through the upper third of epidermis and in bowenoid cases, HPV scatters throughout the whole epidermis including parabasal layers. These findings may indicate that the subtypes of HPV, the interaction of weak oncogenic virus (HPV 6/11) and strong oncogenic virus (HPV 16/18) and the presence of HPV on proliferating cells (parabasal layers) all play a part in oncogenicity. The detectability of HPV 6/11 DNA in both the nucleus and cytoplasm indicate that: 1). In situ DNA.DNA hybridization is a more sensitive method than the immunological detection of capsid antigen. 2). In addition to the nucleus, the cytoplasm is a site through which HPV 6/11 virus should pass during their life cycle. Using PEG hybridization mixture, it was revealed that 6 of the 6 HPV 6/11 positive condyloma acuminata harbored HPV 6. This result indicates that the subtype of HPV determine the gross morphology of skin lesion.

Bowen's Disease↗
PubMed1987

Naevus fusco-caeruleus zygomaticus.

One hundred and ten cases of an unusual type of naevus, which we have called naevus fusco-caeruleus zygomaticus were studied. The naevus presents as a bilateral speckled discolouration of the skin of the face principally in the zygomatic region. The condition usually does not become apparent until the second decade of life, and is much commoner in females. No association with any other abnormalities was found. Light and electron microscopy of the speckles showed the presence of dermal melanocytes mostly in the upper dermis. A survey was also carried out to determine the prevalence of this naevus in the general population.

Adolescent↗
PubMed1987

Study of peripheral T-cell subpopulations and lymphocyte proliferation in different phases of evolution of alopecia areata.

The current hypothesis on the pathogenesis of alopecia areata is immunologically mediated, yet no conclusive data has been documented. To clarify the changes in various phases of disease evolution, analysis of T lymphocyte subpopulations was carried out in the peripheral blood of 34 patients and 27 healthy normal subjects by means of OKT-3, OKT-4, OKT-8 and Ia1 monoclonal antibodies. Study of lymphocyte proliferation in response to various mitogens was further carried out in 27 patients and 25 healthy normal subjects. Significant predominance (p less than 0.01) of OKT-8 positive (cytotoxic/suppressor) cells and diminution (p less than 0.01) of Ia1 positive cells were noted in the whole alopecia group and in various subgroups of disease evolution. Since diminution (p less than 0.05) of OKT-4 positive (inducer/helper) cells was also noted in the stable phase, it was postulated that these activated T cells migrated from circulation to the local site of primary event. Hence, it was evident that the predominance of cytotoxic/suppressor cells was a relative change, and the role of inducer/helper cells in the pathogenesis was implicated. No enhancement of lymphocyte proliferation was observed.

Adolescent↗
PubMed1985

Report of a family with mal de Meleda in Taiwan: a clinical, histopathological and immunological study.

A family in Taiwan is reported to have Mal de Meleda with possibly autosomal recessive inheritance among 5 of its members. The glove- and sock-like erythrokeratosis and the hyperkeratotic plaques of the knees and elbows are the common features. Erythema of the nose, cheeks, and the perioral area in 4 affected members, actinic elastosis in 2 severely affected members, and partially impaired cell-mediated immunity in vitro in both affected and unaffected members are notable findings. Tigason (etretinate) treatment was beneficial in regard to hyperkeratinization, but not to erythema.

Adolescent↗
PubMed1985

Clinical findings and immunological abnormalities in Yu-Cheng patients.

An outbreak of poisoning caused by ingestion of rice bran oil which was accidentally contaminated with polychlorinated biphenyls (PCBs) broke out in Taiwan in February 1979. Diagnosis, management, and follow-up of the patients were performed at special clinics, and subjective symptoms and cutaneous changes such as peculiar acneform eruptions and pigmentation were recorded. The patients were divided into six age groups of both essex, and the body surface of the patients was divided into 12 sections according to the nature of skin. The prevalence of each type of cutaneous change was proved statistically by the chi-square test. The examination of the immune system function in the patients at 1 year revealed: decreased concentration of IgM and IgA but not of IgG; decreased percentage of total T-cells, active T-cells, and helper T-cells, normal percentage of B-cells and suppressor T-cells; suppression of delayed type response to recalling antigens; enhancement of lymphocyte spontaneous proliferation; and enhancement of lymphocyte proliferation with PHA, PWM, and PPD stimulation but not ConA. Follow-up studies 3 years later showed decreased blood PCB levels; some improvement of subjective symptoms and cutaneous changes; recovery of skin testing response to PPD; normal percentage of total T-cells and increased percentage of suppressor T-cells; and enhancement of lymphocyte proliferation spontaneously or under the stimulation of various mitogens.

Adolescent↗
PubMed1985

Clinical significance of anti-nDNA antibodies in ANA-positive systemic lupus erythematosus: comparison of the Farr radioimmunoassay and the Crithidia luciliae immunofluorescent technique.

To evaluate the clinical applicability of anti-native DNA antibodies (anti-nDNA) in systemic lupus erythematosus (SLE), two conventional methods--the Farr radioimmunoassay (Farr assay) and the Crithidia luciliae immunofluorescent technique (CL-IF assay)--were compared in 180 sera of antinuclear antibody (ANA)-positive systemic lupus erythematosus (85 active and 95 inactive), 31 sera of ANA-positive non-SLE rheumatic diseases and 40 sera from healthy subjects. The results further appraised the clinical significance of anti-nDNA antibodies in the diagnosis of systemic lupus erythematosus, especially those patients with nephritis. The CL-IF assay was found less sensitive in the detection of anti-nDNA than the Farr assay. As a tool for differentiating SLE from non-SLE rheumatic diseases, the CL-IF assay is not as sensitive as the Farr assay (sensitivity of CL-IF and Farr assay = 38.3% versus 60.0%). But the CL-IF test is much more convenient and efficient in the detection of active stage SLE and lupus nephritis than the Farr assay. The efficiency of anti-nDNA tests by the CL-IF and Farr assays for diagnosing active SLE were 85.8% versus 79.6%, for lupus nephritis were 76.1% versus 64.4% and finally for both conditions were 81.7% versus 62.2%. As an index of disease activity during the course of treatment, titers of anti-nDNA antibodies by Farr assay proved much more reliable than those by Crithidia luciliae assay. For the detection of anti-nDNA antibodies, simultaneous utilization of these two methods for fresh cases and using the Farr assay alone during the course of treatment are recommended.

Animals↗
PubMed1984

Dermatological, medical, and laboratory findings of patients in Taiwan and their treatments.

This paper describes in detail the dermatological, medical, and laboratory findings of patients poisoned with PCBs and related compounds in Taiwan. Together with their symptoms, their skin lesions as well as their hematological, immunological, and other clinical features are explained. A grading of their clinical severity was tried, and its possible association with PCB concentrations in their blood was examined but could not be demonstrated. Various treatments have been applied but without notable success. Even so, a follow-up study of patients one year later showed that about 38% of patients were somewhat clinically improved, while 54% were not altered.

Acne Vulgaris↗
PubMed1984

PCB poisoning in Japan and Taiwan. Dermatological, medical, and laboratory findings of patients in Taiwan and their treatments.

This paper describes in detail the dermatological, medical, and laboratory findings of patients poisoned with PCBs and related compounds in Taiwan. Together with their symptoms, their skin lesions as well as their hematological, immunological, and other clinical features are explained. A grading of their clinical severity was tried, and its possible association with PCB concentrations in their blood was examined but could not be demonstrated. Various treatments have been applied but without notable success. Even so, a follow-up study of patients one year later showed that about 38% of patients were somewhat clinically improved, while 54% were not altered.

Acne Vulgaris↗
PubMed1984

Altered distribution of lymphocyte subpopulations and augmentation of lymphocyte proliferation in chronic PCB poisoned patients.

To clarify the mechanism of immunotoxicity of polychlorinated biphenyls (PCB), delayed type hypersensitivity skin test, lymphoproliferative responses, and lymphocyte subpopulations defined by monoclonal antibodies were performed on 30 patients and 38 age/sex-matched healthy individuals. Three years ago the patients had ingested rice bran oil accidentally contaminated by PCB. Except for lymphocyte proliferation, the chronic effect of PCB and its derivatives upon cell-mediated immunity (CMI) in these patients was not so evident when compared to that found within one year of exposure. Delayed type hypersensitivity skin response to purified protein derivative (PPD) and the numbers of peripheral T and B lymphocytes were within normal range. The enumeration of lymphocyte subsets demonstrated decreased T4 (inducer/helper) cells and increased T8 (cytotoxic/suppressor) cells. The abnormally augmentated spontaneous proliferation and proliferation responses to phytohemagglutinin (PHA), concanavalin A (Con A), pokeweed mitogen (PWM) and PPD implicated that both T and B lymphocytes were functionally affected. This may well be the result of the immunotoxicity rather than the enhancement of cell-mediated immunity by these toxic compounds. While there was no correlation between the results of those assays and blood PCB levels, it appears that the lymphoproliferative assay may be applied as a sensitive test in reflecting the severity of PCB immunotoxicity.

Chronic Disease↗