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Biomedical subjects

B Yu

Publications and source records attributed to B Yu.

At least 235 records · Page 13Linked to original sources

[Specific binding and internalization of anti-CCT2 monoclonal antibody and bleomycin A6 conjugate in human leukemia cells].

The immunoconjugate of anti-CCT2 monoclonal antibody linked to bleomycin A6 was adsorbed on colloidal gold particles (McAb-A6-Au). Binding and internalization of McAb-A6-Au particles in human leukemia CEM cells were examined by electron microscopy. After 60 min at 4 degrees C, McAb-A6-Au particles were bound to the surface membrane of 78% of CEM cells. Transferring to 37 degrees C for 15 min, McAb-A6-Au particles were found to be 56% inside the CEM cells and about one third of the cells contained particles in the nucleus. After 4 h at 37 degrees C the percentage of CEM cells containing McAb-A6-Au particles increased to 72%. However, only 14% of the antigenically irrelevant U937 cells contained these particles and none of them was found in the nucleus. Preincubation with unconjugated anti-CCT2 monoclonal antibody markedly blocked the McAb-A6-Au particle uptake in CEM cells. The McAb-A6-Au particles were internalized through the formation of endocytotic vesicles. In addition, some McAb-A6-Au particles were able to penetrate the plasma membrane directly into cytoplasma and notably into the nucleus. Results indicate that the immunoconjugate of monoclonal antibody linked to bleomycin A6 showed selective binding to target cells and entered the cells specifically and rapidly.

Antibodies, Monoclonal↗

[Preliminary study of atrial natriuretic peptide in patients with cardiac deficiency and its clinical significance].

Immunoreactive atrial natriuretic peptide (irANP) has been measured in 24 patients of various cardiac diseases by radioimmunoassay. According to the TCM, these patients were divided into 4 groups: cardiac energy deficiency mild (A) and severe (B) groups; simple cardiac deficiency (C); and the control (D). The New York Heart Association (NYHA) classification of cardiac function in 5 cases of group A were all degree IV; in 6 cases of group B were 2 of degree IV and 4 of degree III; in 6 cases of group C were 1 of degree III, 3 of degree II and 2 of degree I; and in 6 cases of group D were all degree I. The results of chest X-ray and echocardiogram suggested that the classification of cardiac function was objective. The quantity of irANP in group A-D and NYHA IV-I decreased gradually and was correlated with left ventricular ejection fraction (r = -0.87, P less than 0.01). The average amounts of irANP in the different TCM groups A-D were at the equivalent levels in the groups NYHA IV-I. Meanwhile it was found that the cardiac energy deficiency patients had abnormality in some parameters of hemorrheology, but no correlation with irANP. It suggested that the diagnosis of cardiac deficiency by TCM was correlated with the different degree of NYHA in the sense of biochemical index of irANP. The irANP might be considered as one of the objective signs of the cardiac energy deficiency, which also might represent the severity of the disease.

Atrial Natriuretic Factor↗

[Experimental study on the antigoiter effect of high casein nutrition].

In this experiment, goiter was successfully induced in rat with MMI, and the antigoiter effect of 25% and 50% casein diet was observed. The results showed that the diet with 50% casein is more effective than that with 25% casein in counteracting MMI and preventing goiter in rat. The antigoiter mechanisms of high protein nutrition might be as follows: Protecting the mechanism of thyroid iodine transportation through the follicular cell, and therefore accelerating thyroid iodine metabolism; Relieving thyroid peroxidase (TPO) from the inhibitive effect of MMI and facilitating thyroid hormone synthesis; Coordinating the function of hypothalamus-pituitary-TSH-thyroid axis and protecting the wholeness of thyroid cell and thus avoiding the occurrence of pathological changes.

Animals↗

Differential attitudes of Chinese students toward people with disabilities: a cross-cultural perspective.

The purpose of this study was to examine the attitudes of 338 Chinese secondary school students toward three major disability groups (people who are physically disabled, emotionally disturbed, and mentally retarded) using an adaptation of the American Scale of Attitudes toward Disabled Persons (SADP). We found that physically disabled persons were rated higher across the three subscales of the SADP compared to either emotionally disturbed and mentally retarded individuals, who were rated similarly low by the students. The lack of differentiation between the two mental handicapping conditions is at variance with contemporary western findings. The overall negative attitudes toward people with mental disabilities may have significant implications for community rehabilitation programming for this population.

Adolescent↗

Immediate hypersensitivity skin reactions to human dander in atopic dermatitis. Partial purification and characterization of human dander allergens.

Using high-speed gel filtration chromatography, an aqueous extract of human dander was divided into four fractions (fractions I to IV). Scratch tests with the crude human dander extract and each fraction were performed in 147 patients with atopic dermatitis and 100 control subjects. The crude extract provoked positive reactions in 61.9% (91/147) of patients with atopic dermatitis and 6% (6/100) of control subjects. The most potent allergenic component was present in fraction II, which induced positive reactions in 61.2% (90/147) of patients with atopic dermatitis. Sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis demonstrated that fraction II contained two proteins with molecular weights of 10,000 and 13,000, respectively.

Adolescent↗

Specificity of the fatty acyl moieties of diacylglycerol for the activation of calcium-activated, phospholipid-dependent protein kinase.

The specificity of the fatty acyl moieties of diacylglycerol for the activation of Ca2+-activated, phospholipid-dependent protein kinase was investigated. Diacylglycerol has been previously shown to activate this enzyme by increasing the affinity for Ca2+ and phospholipid, both of which are indispensable for the enzyme activation. Diacylglycerols containing at least one unsaturated fatty acid at either position 1 or 2 are fully active in this capacity, irrespective of the chain length of the other fatty acyl moiety in the range tested, C2 to C18. Diacylglycerols containing two saturated fatty acids such as dipalmitin and distearin are far less effective. Mono- and triacylglycerols and free fatty acids are totally inactive, indicating that the diacylglycerol structure is essential.

Animals↗

Invasive aspergillosis. Progress in early diagnosis and treatment.

Ninety-one patients with documented invasive infections due to an Aspergillus species were identified at Memorial Sloan-Kettering Cancer Center from July 1, 1971, through December 31, 1976. Of the 29 patients in whom the diagnosis was made during life, 10 had successful treatment and survived the Aspergillus infection by two to 17 months. An immunodiffusion test was useful in the early diagnosis of invasive aspergillosis, and in 11 patients in whom the diagnosis was supported by seroconversion and who underwent treatment, the survival rate was 64 percent. Cultures of respiratory secretions were not reliable because they often reflected only colonization. In one year, only 9 percent of he patients with Aspergillus species isolated from the sputum had an invasive infection. The lung was the commonest site of involvement, 91 percent of the patients having pulmonary lesions. The most frequently affected extrapulmonary organ was the brain (18.3 percent). Eight patients had nonpulmonary aspergillosis as the only manifestation of this infection. Most of the 91 patients had hematologic neoplasms as the underlying disease, and neutropenia and antibacterial therapy preceded the diagnosis of aspergillosis in the majority of cases.

Adolescent↗

Widespread occurrence of calcium-activated, phospholipid-dependent protein kinase in mammalian tissues.

Ca2+-activated, phospholipid-dependent multifunctional protein kinase originally found in rat brain occurs in a variety of mammalian tissues. In most tissues the enzyme activity is comparable to that of cyclic AMP-dependent protein kinase when assayed with calf thymus H1 histone as phosphate acceptor. In some tissues such as platelets, brain, and lymphocytes the enzyme far exceeds the cyclic AMP-dependent enzyme. This species of protein kinase found in various tissues shows very similar physical, kinetic, and catalytic properties, and does not appear to show tissue and species specificities. It is conceivable that this protein kinase plays roles in transmembrane control of protein phosphorylation by a large number of extracellular messengers which induce phosphatidylinositol turnover in their target tissues.

Animals↗

Inhibitory action of chlorpromazine, dibucaine, and other phospholipid-interacting drugs on calcium-activated, phospholipid-dependent protein kinase.

Ca2+-activated, phospholipid-dependent protein kinase recently found in mammalian tissues (Takai, Y., Kishimoto, A., Iwasa, Y., Kawahara, Y., Mori, T., and Nishizuka, Y. (1979) J. Biol. Chem. 254, 3692-3695) is inhibited by various phospholipid-interacting drugs such as chlorpromazine, imipramine, phentolamine, dibucaine, verapamil, and tetracaine. This effect is attributed to the inhibition of the activation process but not to the interaction with the active site of enzyme. This is supported by the fact that a catalytic fragment of this enzyme, which is obtained by limited proteolysis with Ca2+-dependent neutral protease, is fully active without without Ca2+ and phospholipid and is not susceptible to any of these drugs. Kinetic analysis suggests that these drugs cause such inhibition competitively with phospholipid. None of these drugs appears to compete with Ca2+ or to counteract the unique effect of unsaturated diacylglycerol. Unsaturated diacylglycerol has been shown previously to increase markedly the affinity of enzyme for Ca2+ as well as for phospholipid and thereby serve as an initiator for the activation of this protein kinase. Neither cyclic AMP-dependent nor cyclic GMP-dependent protein kinase is susceptible to these phospholipid-interacting drugs.

Animals↗

Diagnosis of invasive aspergillosis by passive hemagglutination assay of antibody.

Sheep red cells treated with concanavalin A and sensitized with a partially purified aspergillus antigen were used to detect antibody to Aspergillus by passive hemagglutination (PHA). Sera from eight patients with aspergillomas or allergic aspergillosis had PHA titers of greater than or equal to 1:800 and antibody detectable by immunodiffusion (ID). Of 122 hospitalized cancer patients without invasive aspergillosis, 118 had titers of less than or equal to 1:80, 86 of < 1:10, two of 1:160, and two of 1:320. None had antibody by ID. Antibody was detectable by PHA in sera from 12 of 14 healthy microbiology laboratory workers. Of 55 cancer patients who had sera available for testing within two weeks before diagnosis of invasive aspergillosis, 18 patients seroconverted: 13 by both PHA and ID, two by PHA alone, and three by ID alone. PHA titers rose from < 1:10 to between 1:40 and 1:1,280. In immunosuppressed patients who were at risk of developing invasive aspergillosis, the appearance of antibody correlated with the diagnosis of invasive aspergillosis.

Antibodies, Fungal↗