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Biomedical subjects

Z Wu

Publications and source records attributed to Z Wu.

At least 433 records · Page 24Linked to original sources
PubMed1998

[Determination of digoxin-like immunoreactive substances in sera of 15 elder patients with cardiac insufficiency].

The presence of a higher concentration of digoxin-like immunoreactive substances (DLIS) in human serum have been reported in a number of pathophysiological conditions. DLIS can react with anti-digoxin antibodies when determination of serum digoxin was performed with immunoassay. It may falsely elevate the serum digoxin concentration and is troublesome in the therapeutic monitoring of digoxin. The apparent digoxin concentrations (DLIS) in serum were determined in 15 elder patients with cardiac insufficiency by fluorescence polarization immunoassay (FPIA). The lowest measurable concentration, defined as the concentration that could be distinguished from zero with 95% confidence, was 0.256 nmol.L-1. Steroids and drugs commonly administered with digoxin showed no significant cross-reactivity. In these patients, the positive ratio for determination of DLIS was 46.7% (7 in 15 cases), and its mean serum concentration was 0.55 +/- 0.44 nmol.L-1 (range 0.26-1.52 nmol.L-1). The results were well consistent with that obtained by Dasgupta et al. In conclusion, there are certain increased concentrations of DLIS in the sera of elder patients with cardiac insufficiency, suggesting that digoxin levels measured by immunoassay method must be interpreted carefully in these patients after treatment with digoxin or other digitalis preparations.

Aged↗
PubMed1998

[The morbidity investigation of residents in a highly endemic village of schistosomiasis in Poyang Lake region].

AIM: To investigate the morbidity of residents in a highly endemic village of schistosomiasis, and to evaluate the usefulness of ultrasound in morbidity study. METHODS: Morbidity induced by Schistosoma japonicum was evaluated and compared in target population by using parasitological examination, ultrasound investigation and medical history questionnaire. RESULTS: The schistosome infection rate was 22.9% in the study population and the prevalence of abnormal ultrasound findings in the liver and spleen was high. The abnormal ultrasound findings correlated with sex significantly, the abnormality of liver parenchyma correlated with age, sex, infection status, occupation and the number of treatment after multiple logistic regression analysis. CONCLUSION: The ultrasound examination could find out the direct pathological changes resulting from schistosome infection.

Adolescent↗
PubMed1998

[Segmentation of osteomas X-ray image using mathematical morphology].

In this paper, we introduce a method for the segmentation of osteomas X-ray images. This method is mainly based on mathematical morphology. Structuring elements are selected according to the shape of osteomas. After gray scale morphology operations, osteomas boundary is extracted by histogram threshold. Further processing of resulting boundary with binary morphological operation produces a closed osteomas contour. So osteomas is isolated from background.

Bone Neoplasms↗
PubMed1998

[The effects of fibronectin on the attachment and proliferation of periodontal ligament cells].

The purpose of this in vitro study was to observe and evaluate the effects of fibronectin(FN) on the growth of periodontal ligament cells(PDLC) on different root surfaces. Cell culture and scanning electronic microscopic techniques were used. The results showed that the growth pattern of PDLC on normal root surfaces were better than that of periodontitis. FN can significantly enhanced the attachment and proliferation of PDL cells on normal root surfaces. On the other hand, only the enhancement of attachment by FN was observed on the periodontitis root surfaces. It may be concluded that FN can promote the growth of PDLC and FN may play different effects on the attachment and proliferation of PDLC.

Cell Division↗
PubMed1998

[Effects of biomaterials on immunoglobulins and biochemistry in serum of extracoporal circulation].

The polyvinyl chloride(PVC) tube coated with cellulose acetate(CA), polyether suffone(PES), polyurethane(PU), silicon rubber(SR) and polyester fibre(PETF) were put in contact with circular serum at 37 degrees C. According to different time-periods of exposure, the immunoglobulins (G.A.M), albumin(ALB), total protein (TP) and total cholesteral(Tch) in serum were measured by an IL-Monarch biomedical analyser. The results showed that the levels of immunoglobutins significantly decreased after the serum came in contact with CA, PETF, SR and that the levels of ALB, TP and Tch were significantly lower in the serum exposed to PETF while those in the serum exposed to other materials were normal. These changes may relate to the complement activation induced by different materials.

Biocompatible Materials↗
PubMed1998

[Chemical pattern recognition of traditional Chinese medicine kudingcha (I)].

In this paper, the non-linear mapping method of pattern recognition was adopted to classify 78 samples of traditional Chinese medicine Kudingcha, with macro and trace elements as classified characteristic features. Ilex cornuta Lindl., Ilex latifolia Thunb. and Ligustrum lucidum Ait. were identified accurately. The results agree with those from pharmacognosy. This paper provides a new method for identification of traditional Chinese medicine.

Drugs, Chinese Herbal↗
PubMed1998

[Chemical pattern recognition of traditional Chinese medicine kudingcha (II)].

In this paper, the HPLC data from 78 samples of Kudingcha were treated with back propagation algorithm of artifical neural network pattern recognition, and the computer-aided classification of Ilex cornuta Lindl., Ilex latifolia Thunb. and Ligustrum lucidum Ait. was accomplished. This paper provides a scientific, advanced and feasible method for identification of traditional Chinese medicine.

Chromatography, High Pressure Liquid↗
PubMed1998

[TLC identification of Flos Carthami].

In 137 kinds of medicinal meterials included 21 kinds of traditional Chinese patent medicines in Pharmacopoeia such as Qili Powder, character identified constituent of Flos Carthami was found by TLC, and was successful to be used to identification of Flos Carthami in 9 kinds of traditional Chinese patent meicines such as Qili Powder.

Carthamus tinctorius↗
PubMed1998

[Study on chemical components of Momordica charantia].

The paper deals with the study of chemical constituents of the unmatured fruits of Chinese traditional medicine Momordica charantia L. which is usually used as green-stuff. There are two parts of the extracts obtained by ethanol precipitation, and four compounds obtained from the further isolation. They are identified as Vincine, Mycose, Momordicoside A and Momordicoside B.

Drugs, Chinese Herbal↗
PubMed1998

[Studies on the chemical components of Brucea javanica].

Three active components were isolated from treated dry-fruits of Brucea javanica (L.) Merr by chromatographic methods, and they were identified as Brusatol (I), Bruceine D (II), Bruceosidae A (III) by means of UV, IR, 1H-NMR, 13C-NMR spectroscopic analysis methods.

Brucea↗
PubMed1998

[Analysis of air pollutants with a combination of GC/FTIR and GC/MS].

In this paper, the air pollutants were analyzed with a combination of Gas chromatography/Fourier transform infrared spectroscopy (GC/FTIR) and Gas chromatography/Mass spectroscopy (GC/MS). The organic mixture was well separated after a careful adjustment of GC and IR parameters in GC/FTIR. In the identification of unknown components, MS is a main method, while IR is also useful to confirm the results.

English Abstract↗
PubMed1998

[Detection of radical anion of nitrobenzene in situ on palladium electrode in different solvent].

By means of a highly sensitive electrolytic cell installed in the ESR cavity, radical anion of nitrobenzene in the process of nitrobenzene electroreduction on palladium electrode in different solvent is dectected by flowing electrolytic system. The results show that in different solvent the discrimination of the ESR spectra are different, the solvent has an effect on nitrobenzene radical anion. The nitrobenzene electroreduction on Pd electrode must produce radical anion as an intermediate.

English Abstract↗
PubMed1998

[Direct determination of zinc in polymerized rosin by flame atomic absorption spectrometry].

Using 95% ethanol as the solvent, we directly determined zinc in polymerized rosin by flame atomic absorption spectrometry. The recovery rate is from 100 to 103 percent. The relative standard deviation (RSD) of the determination is between 1.1-4.1%. The sensitivity is high and the characteristic concentration reaches 0.0077 microg x mL(-1)/1%. The method is quite significant in forestry chemical works with its simplicity and efficiency.

English Abstract↗
PubMed1998

C-TAK1 protein kinase phosphorylates human Cdc25C on serine 216 and promotes 14-3-3 protein binding.

Cdc25C is a dual-specificity protein kinase that controls entry into mitosis by dephosphorylating Cdc2 on both threonine 14 and tyrosine 15. Cdc25C is phosphorylated on serine 216 throughout interphase but not during mitosis. Serine 216 phosphorylation mediates the binding of 14-3-3 protein to Cdc25C, and Cdc25C/14-3-3 complexes are present throughout interphase but not during mitosis. Here we report the cloning of a human kinase denoted C-TAK1 (for Cdc twenty-five C associated protein kinase) that phosphorylates Cdc25C on serine 216 in vitro. C-TAK1 is ubiquitously expressed in human tissues and cell lines and is distinct from the DNA damage checkpoint kinase Chk1, shown previously to phosphorylate Cdc25C on serine 216. Cotransfection of Cdc25C with C-TAK1 resulted in enhanced phosphorylation of Cdc25C on serine 216. In addition, a physical interaction between C-TAK1 and Cdc25C was observed upon transient overexpression in COS-7 cells. Finally, coproduction of Cdc25C and C-TAK1 in bacteria resulted in the stoichiometric phosphorylation of Cdc25C on serine 216 and facilitated 14-3-3 protein binding in vitro. Taken together, these results suggest that one function of C-TAK1 may be to regulate the interactions between Cdc25C and 14-3-3 in vivo by phosphorylating Cdc25C on serine 216.

14-3-3 Proteins↗
PubMed1998

Fibronectin modulates the effects of HIV-1 Tat on the growth of murine Kaposi's sarcoma-like cells through the down-regulation of tyrosine phosphorylation.

HIV-1 Tat plays a role in the pathogenesis of Kaposi's sarcoma. We therefore investigated the effect of Tat on the growth of murine Kaposi's sarcoma-like spindle (TTB) cells derived from dermal lesions. We observed that Tat and a peptide corresponding to the carboxyl-terminal region (Tat65-80) containing an RGD sequence inhibit TTB cell proliferation only when cells are cultured on fibronectin. This inhibitory effect correlates with redistribution of the alpha(v) integrin subunit on the surface of TTB cells and with down-regulation of tyrosine phosphorylation of specific substrates due to an increased tyrosine phosphatase activity. Indeed, phenylarsine oxide, a potent inhibitor of phosphotyrosine phosphatases, prevented the effects of Tat on TTB cells. We therefore argue that the action of Tat on TTB cells is mediated by the RGD motif through an integrin-based cell signaling pathway involving the activity of phosphotyrosine phosphatase(s), which would lead to a decrease in the levels of phosphotyrosine-containing proteins, among which is erk-2/p42MAPK.

Animals↗