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Biomedical subjects

Y S Kao

Publications and source records attributed to Y S Kao.

At least 19 recordsLinked to original sources
PubMed2001

Endothelin-1 increases glucose transporter glut1 mRNA accumulation in 3T3-L1 adipocytes by a mitogen-activated protein kinase-dependent pathway.

The mechanism of enhancing glucose transport by prolonged endothelin-1 (ET-1) treatment of 3T3-L1 adipocytes was examined. Western and Northern blot analyses indicated that ET-1 increased the amount of both GLUT1 protein and mRNA. The degradation rate of GLUT1 mRNA as measured in the presence of actinomycin D, nevertheless, was not significantly altered by ET-1. Whereas various inhibitors for distinct signalling pathways were tested, only the mitogen-activated protein kinase (MAPK) kinase inhibitor, PD98059, was found to decrease significantly the enhancing effect of ET-1. Similar extent of inhibition was observed in cells pretreated with pertussis toxin (PT). Immunoblot analysis revealed that ET-1 may stimulate a transient phosphorylation of p42/p44 MAPK and both PT and PD98059 inhibited this stimulation. In addition, the effect of ET-1 on GLUT1 mRNA accumulation was inhibited by PD98059 and cycloheximide, implying that a trans-activation was involved. Taken together, these results suggest that ET-1 may induce GLUT1 gene expression by a MAPK-dependent mechanism.

3T3 Cells↗
PubMed1999

Persistent infection of a lymphoma cell line by herpes simplex virus.

The peripheral blood cells from a patient with a B-cell lymphoma were established in long-term tissue culture. Two years after establishment of the cells in culture they were infected with herpes simplex virus type 2 and the productivity and duration of viral persistence investigated. One week after infection the lymphoblastoid cells were productively infected and have remained so for a period of over 3 years. Expression of a viral glycoprotein antigen was evaluated by using a fluorescein-labeled monoclonal anti-herpes simplex virus type 2 antibody and revealed a spectrum of staining reactions grading from a lightly stippled to very intense pattern. Polymerase chain reaction analysis of the infected cells revealed the presence of the herpes simplex virus type 2 DNA polymerase gene in the infected cells that was absent from the uninfected lymphoblastoid cells. These results taken together with the long-term growth characteristics of both the infected and uninfected lymphoblastoid cells suggest that this cell line may be a good model system for studying viral infection, viral replication, viral latency, and clinical application for the isolation of human herpes virus.

Adult↗
PubMed1999

Estimating the ozone formation potential of volatile aromatic compounds in vehicle tunnels.

Two vehicle tunnels located in the Taipei area were selected to study the ozone formation potential of volatile aromatic compounds (VACs). Air samples in the two tunnels were collected using canisters. Analysis of VACs was conducted with a gas chromatograph equipped with a mass spectrometer. The total VOCs concentrations in Zefun tunnel ranged from 483.5 to 1032.2 (micrograms/m3) which increased with the increase in traffic volume. In the Lishin tunnel, the total VACs concentration ranged from 356.6 to 1961.3 (micrograms/m3) which was not well correlated with the traffic volume. The most predominant VACs in these vehicle tunnels were toluene and xylenes. Although the traffic volume and types of vehicles were not exactly the same, the characteristic ratios of the VACs concentrations were found to be similar. These results indicated that the existence of a specific characteristic ratio of VAC concentration was affected by the mobile sources. The maximum ozone formation potential resulted from the vehicles in the Lishin motorcycle tunnel which had higher values than the Zefun tunnel and much higher than the SPECIATE databases in the US via weighting the maximum incremental reactivity (MIR) scale.

Air Pollution↗
PubMed1999

Synergistic effect of arachidonic acid and cyclic AMP on glucose transport in 3T3-L1 adipocytes.

The combined effect of arachidonic acid and cAMP on glucose transport was examined in 3T3-L1 adipocytes. In cells pre-treated with arachidonic acid and increasing concentrations of 8-bromo cAMP for 8 h, although either agent alone enhanced glucose uptake, the simultaneous presence of both agents dramatically increased 2-deoxyglucose uptake in a synergistic fashion. Insulin-stimulated glucose transport, on the other hand, was only slightly affected. The synergistic effect of these two agents was abolished in the presence of cycloheximide. Immunoblot analysis revealed that the contents of ubiquitous glucose transporter (GLUT1) in total cellular and plasma membranes were similarly augmented in cells pre-treated with both arachidonic acid and 8-bromo cAMP, to a greater extent than the additive effect of each agent alone. The content of GLUT4, on the other hand, was not altered under the same experimental conditions. In cells pre-treated with 4beta-phorbol 12beta-myristate 13alpha-acetate (PMA) for 24 h to down-regulate protein kinase C (PKC), the subsequent synergistic effect of arachidonic acid and 8-bromo cAMP was greatly inhibited. In addition, pre-treatment with both PMA and 8-bromo cAMP enhanced glucose transport in a similarly synergistic fashion. Thus the present study seems to indicate that arachidonic acid may act with cAMP in a synergistic way to increase glucose transport by a PKC-dependent mechanism. The increased activity may be accounted for by increased GLUT1 synthesis.

3T3 Cells↗
PubMed1999

Phalloplasty in female-to-male transsexuals using free radial osteocutaneous flap: a series of 22 cases.

From July 1994 to December 1996, 22 cases of primary female transsexualism received phalloplasty using free radial forearm osteocutaneous flaps in The Veterans General Hospital, Taipei, Taiwan. Follow-up period ranged from 6 months to 35 months. No complete flap loss and one partial loss (10% reduction) were noted after operation. The urethrocutaneous fistula rate was 40.9%, needing fistula repair surgery. Urethral stricture was noted in three cases (13.7%). Significant donor forearm morbidity was noted in two cases (9.1%) including one who suffered from radius bone fracture. All preserved 'clitorises' had intact erotic sensation and all neophalli gained protective sensation within 9 months. No 'penile fracture' was noted. In nine cases that have regular sexual activities, the sexual performance was rated as satisfactory. We share our experience and recommend that the free radial forearm osteocutaneous tubing flap is a promising choice for phalloplasty in female-to-male transsexuals.

Bone Transplantation↗
PubMed1998

Glans sculpting in phalloplasty--experiences in female-to-male transsexuals.

An aesthetically appealing neophallus with an urethral meatus at its tip is one of the goals of phalloplasty in female-to-male transsexuals. From July 1993 to December 1996, 20 cases of female-to-male transsexuals who had received sculpting of glans in four different ways were enrolled. Their photographs were collected and were scored by independent surgical and non-surgical assessors. The Norfolk procedure creates a more normal neoglans assessed by patients themselves and by the assessors. Split-thickness skin graft (SSG) produces a more normal-looking coronal sulcus than full-thickness skin graft (FTSG) in the Norfolk procedure.

Adult↗
PubMed1998

Epicanthoplasty with modified Y-V advancement procedure.

The presence of epicanthal folds and lack of supratarsal folds are unique features in most Asian eyelids. Although many surgical procedures are available to eliminate epicanthal folds, scarring on the medial canthus is still an obstacle for surgeons to overcome. From January of 1989 to November of 1997, we used modified Y-V advancement procedures in 148 cases to correct epicanthal folds in Asian eyelids. Five of those cases involved congenital palpebral anomalies, including congenital entropion, congenital ptosis, and Down syndrome. There were few complications in our series. We believe that the modified Y-V advancement procedure causes minimum scarring on medial canthus in correcting Oriental epicanthal folds and congenital palpebral anomalies. This procedure can also be simultaneously combined with blepharoplasties and corrective procedures of eyelids.

Adolescent↗
PubMed1994

Ultrastructure, ZIO-staining and chromaffinity of gerbil pinealocytes.

The ultrastructure and cytochemistry of the gerbil pineal gland were studied by the conventional electron microscopy, zinc iodide-osmium tetroxide (ZIO) staining and chromaffin reaction. Conventional electron microscopy revealed that the ultrastructure of gerbil pinealocytes are similar to other rodents, i.e., irregular cell contour with numerous cytoplasmic processes, round or oval nucleus and prominent nucleoli, elongated mitochondria with flattened and tubular cristae and dense matrix, well-developed Golgi apparatus and its associated structures, abundant elements of endoplasmic reticulum--both smooth and rough varieties, and bundles of microfilament and microtubule in the cytoplasm. Some pinealocyte processes contain numerous small clear and "slightly coated" vesicles. Numerous profiles of varicosities containing small dense-cored and clear vesicles were frequently encountered. After ZIO treatment, ZIO staining was preferentially localized in the cytoplasm of some, but not all, of the gerbil pinealocytes. Numerous small clear vesicles (30-50 nm in diameter) in the process of the pinealocytes or in the varicosities of the nerve fibers showed strong ZIO-philia. After chromaffin reaction treatment, the number and electron density of small clear and dense-cored vesicles in the profiles of nerve varicosities increased and this indicates that some of the small clear and dense-cored vesicles in the varicosities are reactive. It is thus concluded that (1) the vesicles in the pinealocytes may be rich in cystine and/or cysteine and possibly the organelle is involved in the sequestering calcium ion during the calcification of the pineal concretions, and (2) the small dense-cored and clear vesicles in the nerve fibers in the gerbil pineal parenchyma may contain both serotonin and primary biogenic amines.

Animals↗
PubMed1990

Trisomy 4 in a case of acute undifferentiated myeloblastic leukemia with hand-mirror cells.

A case of acute undifferentiated myelocytic leukemic with trisomy 4 is described. The patient is a 61-year-old woman who developed leukemia 4 1/2 years after receiving radiation therapy for uterine carcinoma. Many leukemic cells exhibited hand-mirror configuration after the bone marrow aspirate was left at room temperature overnight. The relationship between trisomy 4 and hand-mirror cells in acute myelocytic leukemia is unknown.

Bone Marrow Examination↗
PubMed1990

Banding resolution of amniotic cell chromosome preparations for prenatal diagnosis.

Fifty consecutive routine female karyotypes of amniotic fluid cells were analyzed to determine: (1) the banding resolution of each metaphase in routine preparations, (2) whether all haploids in the same metaphase had the same level of banding resolution, and (3) which chromosomes showed the least/most variation in regard to banding resolution. For each karyotype, the number of dark bands for each right-hand-side chromosome were counted and compared with an ideogram (ISCN 1985). Banding resolution was separated into three groups: 400-band, 550-band, and 850-band. It was found that all 50 metaphases showed at least a 400-band resolution, and 1 metaphase showed a banding resolution between a 550-band and 850-band level. Although the chromosome preparations were sufficient for routine purposes, additional effort and banding techniques are required to detect small chromosomal abnormalities that require a higher level of resolution.

Amniotic Fluid↗
PubMed1986

Neo-kyotorphin, an analgesic peptide isolated from human lung carcinoma.

A pentapeptide with analgesic activity has been isolated from human lung squamous cell carcinoma and from three other types of propagated tumors of human lung small-cell carcinoma (SCC), adenoma (AD) and large-cell carcinoma (LCC) in nude mice. The amino acid sequence of the peptide has been revealed to be H-Thr-Ser-Lys-Tyr-Arg-OH, which is exactly the same as that of neo-kyotorphin, an analgesic peptide originally isolated from bovine brain [(1982) Life Sci. 31, 1733]. No neo-kyotorphin could be isolated from normal lung tissue using the same procedures as those used for carcinomas. The results suggest that the presence of neo-kyotorphin in the lung carcinoma may represent the ectopic expression of peptide hormone. Our findings constitute the first example of a human lung carcinoma producing analgesic peptide.

Amino Acid Sequence↗
PubMed1983

A simple, rapid, high-resolution chromosome technic for lymphocytes.

Phytohemagglutinin (PHA) stimulated lymphocytes were exposed to a hypotonic solution consisting of equal parts of 0.075 M 2-Mercaptoethanol and 0.075 M KCl, followed by addition of colcemid. The cells were fixed and washed in the usual manner. The slides then were subjected to trypsin-Giemsa banding. This method yields a high percentage of mitotic figures in prophase and prometaphase, ideal for high-resolution chromosome analysis.

Humans↗