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Biomedical subjects

X Y Yang

Publications and source records attributed to X Y Yang.

At least 91 records · Page 5Linked to original sources
PubMed1990

Effect of astragalus membranaceus on electric activities of cultured rat beating heart cells infected with Coxsackie B-2 virus.

Astragalus membranaceus (AM) which has a protective effect on rat beating heart cells infected experimentally with Coxsackie B-2 virus was evaluated on the basis of changes in morphologic and electric activity of the cells. Rhythm, beating frequency, beating percentage, cardiac cellular damage and cytopathic effects (CPE) were monitored every 24 h after challenge; electric activities parameters were measured by conventional intracellular microelectrode technique. Significant protective effects were demonstrated when AM was given in the early period of infection. The results suggest that AM should be valuable in preventing and treating acute myocarditis caused by Coxsackie B virus.

Action Potentials↗
PubMed1990

Clinical significance of hysterography in the diagnosis of choriocarcinoma and invasive mole.

From 1963 through 1988, a total of 194 hysterographies were performed for 111 patients. Three types of abnormalities were observed on the hysterogram: filling defect, intramural invasion of the uterine wall by the contrast medium; and intravasation of the contrast medium into the pelvic veins. The pathology and clinical significance of three types of abnormalities were studied. The results showed that hysterography demonstrated better images than pelvic arteriography and B-scan for the diagnosis of choriocarcinoma and invasive mole, especially when combined with B-scan/or pelvic arteriography, a greater accuracy was achieved.

Choriocarcinoma↗
PubMed1990

[Colitis due to chemotherapeutic agent].

From 1965 through 1989, a total of 1,382 cases of malignant trophoblastic neoplasms, were treated in our hospital. Colitis related to chemotherapy was observed in 110 cases. This toxic reaction was specific to 5-Fluorouracil treatment and may result in pseudomembranous colitis if improperly treated. Staphylococcus aureus or Clostridium difficile was the causative agent. For the early detection of this disease, it is necessary to monitor the bacteria flora in the smear of fecal substance. Vancomycin and Metronidazole together with lactobacillus preparation were given and proved to be effective in most cases. The mechanism of formation of pseudomembranous colitis, the causative agents and method of diagnosis and treatment were discussed.

Adult↗
PubMed1990

Immunologic methods for the detection of carcinogen adducts in humans.

Monoclonal antibodies have been developed which recognize a number of carcinogen-DNA and protein adducts. These antibodies can be used in highly sensitive competitive enzyme linked immunosorbent assays (ELISA) to detect femtomole levels of adducts in human samples. With the most sensitive antibodies, DNA adducts in the range of 1/10(8) nucleotides can be measured. In addition, antibodies to DNA adducts can be used to investigate immunohistochemically the localization of adducts in specific cell and tissue types. Antibodies recognizing benzo(a)pyrene diol epoxide-DNA have been used to monitor adducts in white blood cell DNA of foundry workers and placental and white blood cell DNA of smokers and nonsmokers. Because of antibody crossreactivity with structurally related adducts of other polycyclic aromatic hydrocarbons, this assay is not specific for benzo(a)pyrene adducts. Antibodies to the stable guanine imidazole ring opened aflatoxin-B1-DNA adduct have been used to detect elevated levels of adducts in liver tissue from Taiwanese hepatocellular cancer patients. Monoclonal antibodies against 8-methoxypsoralen-DNA have been used to monitor adducts in psoriasis and cancer patients treated with psoralen plus UVA light. These patients have also served as model systems for the development of immunofluorescence methods for adduct detection. Immunohistochemical staining of skin biopsies from psoriasis patients demonstrated specific staining of epidermal cells. With further increases in sensitivity, this method should be applicable to the detection of adducts in other human tissues. Adduct detection in humans is now established as a viable method for determination of exposure to certain chemical carcinogens. However, the relationship of adduct measurements to individual risk requires further investigation.

Aflatoxins↗
PubMed1989

The use of Chinese herb medicine in experimental radiotherapy.

Extracts from a group of destagnative herbs, 764-1, and the effective chemical, 764-3, were tested by an in vitro experiment using a HeLa-S3 cell line. Under aerobic conditions, the shoulder of the cell survival curve diminished or disappeared according to the different doses of 764-1 used, but no change in slope was observed. In nitrogen, when the dose of 764-1 increased to 20 mg/ml (ID20), besides the disappearance of the shoulder, the slope of the curve also showed changes at lower doses (4-8 Gy); up to 10-25 Gy the curve became more flattened. 764-3 showed almost a similar effect by mainly affecting the shoulder of the survival curve. At low drug doses a SER as high as 1.87 might be obtained under hypoxic condition. At the same time 764-1 was used in testing the effect on radiation lung damage. It was found that 764-1 could markedly inhibit the change of alveolar surfactant at 1 and 3 weeks after radiation. A wide field of investigation is thus spread out in front of us on radiosensitization and protection. Further studies on 764-3 are carried out.

Animals↗
PubMed1989

8-Methoxypsoralen-DNA adducts in patients treated with 8-methoxypsoralen and ultraviolet A light.

The combination of 8-methoxypsoralen (8-MOP) plus ultraviolet A light (320-400 nm), termed PUVA, is used in the treatment of psoriasis, a hyperproliferative disease of the skin. This treatment results in the formation of specific 8-MOP adducts with cellular DNA. We have previously developed monoclonal antibodies which recognize these 8-MOP photoadducts. We now report the use of these antibodies in an indirect immunofluorescence technique to study human skin biopsies. Nuclei in 3 of 5 skin biopsies from psoriasis patients undergoing PUVA therapy were positive for adducts. The presence of adducts by immunofluorescence did not correlate with plasma levels of 8-MOP. Enzyme-linked immunosorbent assays, used to determine whether 8-MOP photoadducts could be detected in DNA isolated from the lymphocytes of psoriasis patients after PUVA therapy, were negative.

Antibodies, Monoclonal↗
PubMed1989

[Diagnosis and treatment of intrauterine adhesions].

Twenty-four cases of intrauterine adhesions (Asherman's syndrome) were reported. The characteristic clinical picture was amenorrhea of hypomenorrhea accompanied by periodic lower abdominal pain. Intrauterine adhesions were demonstrated by hysterography in 14 cases. Lysis of adhesions was performed in 14 patients through vaginal route and in 3 by abdominal hysterotomy. Cyclic abdominal pain disappeared after treatment in all patients and normal menses were established in 16 cases (94%). In 11 patients with intrauterine adhesions developing after trauma, 3 conceived for 4 times all resulting in full term deliveries of healthy babies. The etiologic factors method of diagnosis and treatment of intra-uterine adhesions and prevention of readhesion are discussed.

Adult↗
PubMed1989

Comparison of magnesium in human lymphocytes and mononuclear blood cells.

The population of mononuclear blood cells (MBCs) separated by a discontinuous gradient from healthy normal volunteers consists of lymphocytes (L), monocytes (M) and relatively few granulocytes (G). We attempted to remove the phagocytic cells (M and G) by pretreatment of the blood with carbonyl iron particles (CIP). In 50 volunteers (21 males and 29 females, ages 17-75, mean 33.3 years), we determined the content and concentration of Mg in MBCs before and after pretreatment with CIP. The results (mean +/- SEM) show a significant decrease in the MBC Mg content (from 3.12 +/- 0.08 to 2.39 +/- 0.05 fmol/cell; p less than 0.0001), concentration (from 10.4 +/- 0.2 to 9.6 +/- 0.3 mmol/l; p less than 0.004) and M percentage (from 14.5 +/- 1.0 to 1.0 +/- 0.2%; p less than 0.0001) after CIP pretreatment. The L percentage significantly increased from 81.6 +/- 1.0 to 96.1 +/- 0.2% (p less than 0.0001) after CIP pretreatment. These date suggest that M have both a larger content and concentration of Mg than L.

Adult↗
PubMed1989

Determination of magnesium in granulocytes.

Determination of magnesium in mononuclear blood cells may provide useful information about intracellular magnesium. Mononuclear blood cell preparations are frequently contaminated with granulocytes. We determined the normal reference interval for magnesium content and concentration of granulocytes and compared it with magnesium in mononuclear blood cells. The mean granulocyte magnesium concentration and content were 6.95 (SD 1.25) mmol/L and 3.11 (SD 0.54) fmol per cell, respectively, vs 10.95 (SD 1.70) mmol/L and 3.27 (SD 0.46) fmol per cell in mononuclear cells. The concentration of magnesium in granulocytes was significantly less (P less than 0.001) than in mononuclear blood cells, but the magnesium contents were not significantly different.

Adult↗
PubMed1989

[Cytotoxic effects of changrolin, lidocaine and amiodarone on ultrastructure of cultured rat beating cardiac myocytes].

Ultrastructural and morphological alterations of cultured rat beating cardiac myocytes treated with changrolin (CRL), lidocaine (Lid), and amiodarone (Ami) were studied. After the cultures were treated with CRL 100 micrograms/ml for 24 h, the beating of the myocytes stopped, the configuration and fine structure were destroyed, while the nuclei showed pyknotic deformation and reduced in size. The membrane and structures of mitochondria were disrupted and myofibrils fragmented and disrupted. In addition, a lot of vacuoles with characteristic dense particles were found in the cytoplasm. Similar alterations were seen when Lid 1000 micrograms/ml and Ami 50 micrograms/ml were added to the cultures. Normal beating networks of myocytes were examined under inverted microscopy after the cultured cells were treated with CRL 25 micrograms/ml, Lid 250 micrograms/ml or Ami 6.25 micrograms/ml. The ultrastructure of some regions of the myocytes showed very slight damage. The results indicated that the dosage of CRL and Lid generally used in anti-arrhythmic therapy basically exerted no harm to myocytes. However, caution should be taken when Ami was given intravenously, since its effective serum concentration was close to the dosage which could cause slight damage to the ultrastructure of cultured cells.

Amiodarone↗
PubMed1988

Effects of 8-methoxypsoralen and ultraviolet light A on EGF receptor (HER-1) expression.

Activation of psoralens by ultraviolet light irradiation at 308-400 nm (UVA) is used in the photochemical treatment of psoriasis. While the major effect of this activation is the formation of DNA adducts, it was recently demonstrated that psoralens can also bind to specific saturable high affinity cellular receptors, and that this is associated with inhibition of epidermal growth factor (EGF)-receptor binding. In view of these findings, we have examined whether 8-methoxy-psoralen (8-MOP) itself, or in combination with UVA, influences expression of the human EGF-receptor gene ("HER-1") in a human keratinocyte cell line. We have found that 8 MOP alone, and to a lesser extent UVA, induce a striking increase in cellular levels of HER-1 RNA. The combination of 8-MOP with UVA produces less induction of HER-1 RNA than that obtained with 8-MOP alone. We suggest, therefore, that this effect of 8-MOP is not due to DNA damage, but may reflect a separate effect of this compound on receptor-mediated signal transduction.

Blotting, Northern↗
PubMed1988

Flow cytometric analysis of 8-methoxypsoralen-DNA photoadducts in human keratinocytes.

Flow cytometric methods have been developed for the analysis of 8-methoxypsoralen-DNA adducts in SV40-transformed human keratinocytes (svk-14). Monoclonal antibodies which specifically recognize these adducts were used in conjunction with fluorescein isothiocyanate-labeled second antibodies and propidium iodide staining to simultaneously determine 8-methoxypsoralen-DNA adduct levels and DNA content, respectively. The sensitivity of the method was determined by quantitation of adduct levels in DNA isolated from treated cells by enzyme-linked immunosorbent assay. Adduct formation during various stages of the cell cycle was also investigated. Two separate cell populations with a DNA content indicative of cells in G1 but with different levels of fluorescein isothiocyanate labeling were observed. Pretreatment of cells with aphidicolin decreased the number of cells in S phase, and only one fluorescein isothiocyanate-staining G1 population was observed. There is an indication of greater adduct formation in S-phase cells when immunofluorescence is corrected for DNA content. These results suggest that adduct formation is not simply linear with respect to DNA content.

Antibodies, Monoclonal↗
PubMed1988

Pregnancy outcomes after successful chemotherapy for choriocarcinoma and invasive mole: long-term follow-up.

In order to preserve the fertility of young patients with choriocarcinoma and invasive mole, chemotherapy alone was given without hysterectomy in 265 cases from 1959 through 1980. By the end of 1985, 205 patients had become pregnant after recovery, with a total of 355 pregnancies. Among these, 23 were terminated by induced abortions, 26 as miscarriages, two as ectopic gestations, two as intrauterine deaths, and three as stillbirths. Among 303 livebirths (including four sets of twins), six infants died neonatally, three of whom were found to have congenital anomalies incompatible with life, and two died during infancy. All the remaining 295 children had normal growth and development, the oldest now being 25 years of age. The rates of fetal wastage, malformations, twin pregnancies, and neonatal and infantile deaths did not deviate from the normal. Cytogenetic study of the peripheral lymphocytes of 94 of the children revealed no increase of chromosomal aberrations. The rates of recurrence of disease and of death caused by recurrence of disease in these were not increased in comparison with those in patients who underwent hysterectomy. These data indicate that treatment of malignant trophoblastic neoplasms with chemotherapy alone is compatible with the preservation of fertility in most women.

Adult↗
PubMed1988

Treatment of the thalassemia syndrome with splenectomy.

Splenectomy was performed on 152 patients with thalassemia (thal), including 90 cases with Hb H disease, 48 cases with homozygous beta-thal, and 14 cases with Hb E-beta-thal. The therapeutic effect in Hb H disease was 83.3%, and 32.3% in Hb E-beta-thal and beta-thal. In Hb H disease, the hemoglobin (Hb) level increased 30 g/l in 14 of 29 cases. After splenectomy, the life-span (T1/2) of 51Cr RBC in Hb H and Hb E-beta-thal increased to 18.2 +/- 2.6 and 18.2 days, respectively. The number of inclusion (Heinz) bodies attached to the RBC membrane increased after surgery. The interdermal delayed supersensitivity reaction became negative in seven of 26 cases of Hb H disease; the IgG also decreased after surgery. The number of PAS positive foam cells in the spleen correlated to Hb level after surgery. Infection is a common complication.

China↗
PubMed1988

Detection and quantification of 8-methoxypsoralen-DNA adducts.

8-Methoxypsoralen (8-MOP) is a photoactivated drug used clinically in the treatment of psoriasis and cutaneous T-cell lymphoma (CTCL). We have developed monoclonal antibodies which specifically recognize 8-MOP-modified DNA and do not cross-react with unmodified DNA or free 8-MOP. Highly sensitive, competitive enzyme-linked immunosorbent assays (ELISA) have been developed with both colour and fluorescence endpoint detection for quantification of DNA adducts in biological samples. In addition, immunofluorescence and flow cytometric techniques have been developed to visualize adducts in tissues and cells. These techniques have been validated in keratinocytes treated in culture and in animals treated in vivo with 8-MOP and ultraviolet A (UVA) light. Adduct levels have also been monitored in skin biopsies and lymphocytes of patients with psoriasis and lymphoma.

Animals↗