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Biomedical subjects

G H Yu

Publications and source records attributed to G H Yu.

At least 37 records · Page 2Linked to original sources
PubMed1996

[rhTGF-beta 1 induced differentiation of human promonocytic leukemia THP-1 cells].

With promonocytic leukemia cell line THP-1 cells as an experimental material, the present paper described the proliferation, differentiation and maturation of these cells into m phi-like cells when they were treated with rhTGF-beta 1. Both cell number count and 3H-TdR uptake experiments indicated that rhTGF-beta 1 obviously inhibited the proliferation of THP-1 cells, and the inhibiting effect was related to its concentration. At the same time, the changes in the mode of cell growth and morphology occurred. The cells changed gradually from suspensive into adherent state and formed two groups of cell populations. The number of adherent cells formed was dependent on the concentration and duration of the treatment of rhTGF-beta 1. Therefore, based on the degree of inhibition of cell proliferation and the number of adherent cells with different rhTGF-beta 1 concentrations in a trial experiment, 1.25 ng/ml rhTGF-beta 1 was chosen as the dose in other experiments. From scanning electronmicroscopic observation, it was found that the external morphology of rhTGF-beta 1 treated THP-1 cells gradually transformed into typical macrophage-like cells. Concomitantly, their subcellular organelles also became progressively matured, with primary lysosomes typical for early M phi in 72 h and secondary lysosomes and phagosomes for mature M phi in 120 h of induction, as observed with transmission electron microscope. The ANAE activity, NBT reduction and phagocytosis of differentiated adherent cells were higher than those of control cells and suspensive cells. Specific anti-human TGF-beta-neutralizing mAb could completely block the differentiation of THP-1 cells into M phi-like cells. To sum up, from the results of the studies on cell morphology, growth mode, ultrastructures, phagocytosis, enzyme activation and TGF-beta 1 mAb blocking of induction and differentiation, it is clear that rhTGF-beta 1 can induce THP-1 cells to differentiate and mature into M phi-like cells, with the parallel development of cytoplasmic organoids, phenotype variation and the gaining of phagocytosis activity etc. Concordantly, rhTGF-beta 1 made the M phi-like cells to an activated state as they became matured during the induced differentiation.

Cell Transformation, Neoplastic↗
PubMed1995

Primary cutaneous osteosarcoma.

A 78-year-old man had a 1-cm cutaneous nodule on his shoulder; subsequent excisional biopsy showed osteosarcoma. There was no connection to deeper structures, and no primary bone lesion was found. The tumor recurred at the same site 9 months after diagnosis and was reexcised. We believe this to be the first well-illustrated case of primary cutaneous osteosarcoma, which should now be included on the list of sarcomas that may occur in the skin.

Aged↗
PubMed1995

Image analysis--derived morphometric differences in fine needle aspirates of ductal and lobular breast carcinoma.

The differentiation of ductal and lobular carcinoma (including lobular carcinoma in situ) of the breast has important prognostic implications; thus, preoperative differentiation of these entities via fine needle aspiration could have a substantial impact on the therapeutic options offered to patients. However, well-defined, reliable light microscopic criteria do not currently exist for their distinction in cytologic preparations, particularly when the differential diagnosis of lobular versus low nuclear grade ductal carcinoma is considered. In this study we utilized a morphometric image analysis system to identify distinct nuclear features useful in the differentiation of these two entities and found that a number of significant differences do exist. Although some features (i.e., nuclear size) may be detected in traditional cytologic preparations, others may not be detected by the human observer, supporting a role for automated morphometric analysis as a useful adjunct in the distinction of lobular and low nuclear grade ductal carcinoma in fine needle aspirates of the breast.

Biopsy, Needle↗
PubMed1994

The effect of limited handrail support on total treadmill time and the prediction of VO2 max.

Holding onto the front handrail during treadmill testing significantly increases total treadmill time (TT) and predicted VO2max when compared with tests without front handrail support. By limiting the amount of handrail support to the tips of two fingers of one hand, the difference in TT can be substantially reduced. In the present study, the difference in TT between tests with and without handrail support for healthy men was not significantly different. However, this was not true for healthy women and for male patients with coronary artery disease and myocardial infarction.

Aged↗
PubMed1993

Adult intracardiac rhabdomyoma resembling the extracardiac variant.

Rhabdomyomas are benign striated muscle neoplasms that may assume a number of characteristic histologic patterns. These lesions may be classified as cardiac or extracardiac on the basis of their location and histology. We present a case of large intracardiac mass with the morphologic features of an extracardiac rhabdomyoma occurring in an adult female.

Adult↗
PubMed1993

Cellular angiolipoma of the breast.

Cellular angiolipomas are benign fatty tumors that occur as multiple subcutaneous nodules on the extremities and trunks of young adults. Although clinically benign, they may occasionally mimic Kaposi's sarcoma or angiosarcoma histologically. We report the first case of cellular angiolipoma occurring in the subcutaneous tissue of the breast, a rare but well-recognized site of benign and malignant vascular tumors.

Breast Neoplasms↗
PubMed1991

Adenosine-5'-O-(3-thiotriphosphate) binding to human neutrophils. Evidence for a common nucleotide receptor.

Human polymorphonuclear neutrophils (PMN) respond to ATP with an elevation in intracellular calcium and a marked enhancement of O2-production in response to stimulation by the chemotactic peptide N'-formyl-Met-Leu-Phe (FMLP). These pertussis toxin-sensitive pathways appear to be mediated by a nucleotide receptor(s) on the surface of human PMN. In the current study, we have examined the binding to intact human PMN of the ATP analog, adenosine 5'-O-(3-thio[35S] triphosphate) [( 35S]ATP gamma S). On the basis of Scatchard analysis, the binding of [35S]ATP gamma S involves at least two sites, one of high and one of low affinity. In the presence of sodium thiophosphate, a compound which did not affect intracellular increases in calcium induced by ATP or N'-formyl-Met-Leu-Phe, a significant fraction of the [35S]ATP gamma S binding was eliminated. This reduction involved both high and low affinity binding of [35S]ATP gamma S and was related to a reduction in numbers of binding sites. The Kd values for the high affinity binding site were unaffected by the presence of sodium thiophosphate, although the low affinity Kd values were numerically increased by 2-fold. In the presence of thiophosphate, [35S]ATP gamma S binding was specific, saturable, and reversible, and was related to a single class of high affinity (Kd = 36 +/- 19 nM) binding sites (184 +/- 144 sites/cell), together with a second class of low affinity (Kd = 1110 +/- 503 nM) binding sites (13,562 +/- 6,851 sites/cells). Competitive binding experiments, based on the ability of nucleotides and ATP analogs to block [35S]ATP gamma S binding to PMN, revealed a rank order of ATP gamma S greater than ATP greater than 2-MeS-ATP = 8-Bromo ATP greater than ADP = ITP greater than AMP-PCP = GTP much greater than CTP. A comparison between the ability of nucleotides to compete with [35S]ATP gamma S binding and their ability to induce a biologic response (elevation of intracellular calcium) revealed a close correlation (r2 = 0.83). These findings support the possibility of a common nucleotide PMN receptor functionally linked to a cellular response which involves increases in intracellular calcium.

Adenosine Triphosphate↗
PubMed1990

[Pulmonary Pseudomonas infections].

145 strains of pathogenic pseudomonas had been isolated from the sputum or bronchoscopic aspirate of 1423 patients with pulmonary infections. They were classified into 8 types, among which 31.7% was pseudomonas aeruginosa. Pseudomonas aeruginosa was the dominant causative organism in pulmonary infections of the aged while in presenile ones the organism was mainly Pseudomonas fetid. The incidence of nosnocomial pseudomonas infection in patients of COPD with respiratory failure was 40%, of COPD with pulmonary infection 9.1% and of others 6.6%. 24 pseudomonas carriers with COPD (colonies less than or equal to 10(6)/ml in sputum) had been followed up. 16 out of them became negative in sputum culture without any treatment, while the remaining 8 developed pulmonary pseudomonas infections. 21 patients (14.5%) were found to have other types of pseudomonas infections during antibiotic treatment. Sensitivity tests showed that third-generation cephalosporins and aminoglycosides had definite antimicrobial activity against pseudomonas, the former being more stable and effective than the latter.

Adult↗
PubMed1989

[Latent risk and precautions against cross infection at the respiratory disease unit].

To investigate the contamination of respiratory pathogens in the ward of respiratory disease, bacterial count was conducted in air of different rooms of the ward. It was found that the air total bacterial count was much higher in the nursing room and ICU than that in the rooms with good ventilation (P less than 0.01). Pathogens were examined in the saliva of the medical staff. No significant difference was found in the pathogens of the saliva between the COPD patients and medical staff, who were considered as bacteria-carriers. 155 times of bacteriologic examinations were made in 68 humidified bottles for oxygen supplement. All bottles had a mixed contamination, with Pseudomonas aeruginosa being one of common pathogens.

Bacterial Infections↗
PubMed1989

[Influence of total parenteral nutrition on amikacin pharmacokinetics].

Six patients under total parenteral nutrition (TPN) and eight control patients received 200 mg of amikacin by iv infusion in 0.5 h. Amikacin concentrations of serum and urine were determined by fluorescence polarization immunoassay. At 6 h after the beginning of administration, the amikacin level in serum of TPN group (2.3 +/- 0.8 micrograms/ml) was significantly higher than control (1.3 +/- 0.8 microgram/ml). There was no significant difference between the 24-h urine output of 2 groups. Pharmacokinetic calculations were based on a two-compartment open-system model. The T1/2 beta and apparent volumes of distribution (Vc, Vdss, V2) of TPN group were significantly greater than those of control group. The body clearance of amikacin in TPN group was slower than control. It is suggested that serum amikacin concentrations should be monitored in clinical TPN patients to prevent toxic reactions.

Adult↗
PubMed1988

Biochemical characterization of membrane cofactor protein of the complement system.

Membrane cofactor protein (MCP; formerly termed glycoprotein 45-70 to indicate its Mr) of complement is a widely distributed iC3/C3b binding protein with co-factor activity. On human mononuclear cells and cell lines and platelets, MCP is a doublet. The two forms differ in Mr by approximately 5 k and the upper species is predominant in most individuals. To further characterize these two forms, limited proteolytic digestions were performed. Of the four peptides produced, three have identical Mr indicating that the molecules are similar proteins. Both forms also have acidic isoelectric points and shift to a less acidic isoelectric point after treatment with neuraminidase. Glycosidase digestions indicate that both species contain N- and O-linked oligosaccharides but that the quantity of sialic acid is greater on the larger one. Pulse-chase experiments demonstrate approximately equal quantities of two precursor forms with Mr of 41 and 43 k. These two precursors possess N-linked high-mannose type of oligosaccharides and chase into the mature molecules which have complex sugars. The smaller precursor chases at a slower rate, possibly accounting for the reduced quantity of the smaller form of the mature form of MCP. These experiments indicate that the two forms of MCP are structurally similar and are derived from two distinct precursors. They also suggest that variations in the rate of processing of two intracellular precursors may account for the different quantities of the mature forms of this membrane protein.

Antigens, CD↗
PubMed1986

Identification of a third component of complement-binding glycoprotein of human platelets.

Utilizing affinity chromatography, a C3-specific binding protein was isolated from 125I surface-labeled human platelets. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis demonstrated two bands with mean Mr of 64,000 and 53,000, characteristic variability in the relative density of the two bands in a given individual, and the presence of N-linked complex oligosaccharides as well as sialic acid residues not associated with N-linked sugars. These characteristics are similar to those of a human leukocyte iC3- and C3b-binding glycoprotein, termed gp45-70. Further analysis showed that leukocyte gp45-70 and the platelet C3-binding glycoprotein have identical Mr and other similar structural features. Functional characterization of solubilized platelet preparations indicated that gp45-70 has cofactor activity. This membrane glycoprotein is structurally and antigenically distinct from decay accelerating factor (DAF), a complement regulatory protein previously identified on human platelet membranes. DAF and gp45-70 have complementary activity profiles inasmuch as DAF can prevent assembly of and dissociate the C3 convertases but has no cofactor activity, whereas gp45-70 has cofactor activity but no decay accelerating activity. We suggest that these two proteins function conjointly to prevent autologous complement activation.

Blood Platelets↗