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Biomedical subjects

W Gong

Publications and source records attributed to W Gong.

97 records · Page 6Linked to original sources

[Simultaneous analysis of vitamin B complex by least square UV-spectrophotometry].

Simultaneous analysis of VitB1, VitB2 and VitB3 in Vitamin B Complex tablets was made by least square UV-spectrophotometry. The results showed that the contents of VitB1, VitB2 and VitB3 could be calculated by computer with least square method using 12 absorbances of 239, 241, 257, 259, 261, 263, 266, 269, 270, 279 and 281 nm wavelengths. The reclamation of VitB1 was 101.4% (CV% = 0.88, n = 3), of VitB2 98.5% (CV = 0.43, n = 3), and of VitB3 101.3% (CV% = 0.15, n = 3).

Least-Squares Analysis↗

[Comparison of immunoenzymatic staining technique (IEST), double gluing strip circumoval precipitin test (DGS-COPT) and conventional circumoval precipitin test (CV-COPT) for diagnosis of schistosomiasis japonica].

IEST, DGS-COPT and CV-COPT using lyophilized ova of schistosoma japonicum were performed on sera from 120 cases of schistosomiasis japonica, 120 cases of schistosomiasis japonica 3-8 years after being cured with praziquantel and 120 healthy individuals by single-blind method. The sensitivity and specificity of IEST was 91.7% and 95.8% respectively which were significantly higher than that of both DGS-COPT and CV-COPT. The negative conversion rate of cured patients was 70.8% with IEST, 80.8% with DGS-COPT and 81.7% with CV-COPT. The results showed that IEST has higher diagnostic value for schistosomiasis than both COPT. DGS-COPT has the same diagnostic value as CV-COPT, however, it was easy to perform and time-saving, thus it might be applied in the fields for practical purposes.

Animals↗

[Immunocytochemical study of monoclonal antibody 83YH2 in stomach cancer].

Using the avidin biotin complex (ABC) immunocytochemical stain, 97 cases of stomach cancer were examined for monoclonal antibody 83YH2. The positive rate was 82.47% (80/97) in stomach cancer with various types of differentiation. Some gastric epithelial cells and intestinal metaplastic cells near the cancer foci also showed weak positivity. But 83YH2 was not detected in normal human tissues. In the same stomach cancer cases, CEA test was also performed. The positive rate and distribution of CEA was almost similar to that of 83YH2, despite the fact that it was verified, by the immunoblock test, that 83YH2 was a different antigen. The results show that 83YH2 is an associated antigen of stomach cancer.

Adenocarcinoma↗

Production of neutrons from interactions of GCR-like particles.

In order to help assess the risk to astronauts due to the long-term exposure to the natural radiation environment in space, an understanding of how the primary radiation field is changed when passing through shielding and tissue materials must be obtained. One important aspect of the change in the primary radiation field after passing through shielding materials is the production of secondary particles from the breakup of the primary. Neutrons are an important component of the secondary particle field due to their relatively high biological weighting factors, and due to their relative abundance, especially behind thick shielding scenarios. Because of the complexity of the problem, the estimation of the risk from exposure to the secondary neutron field must be handled using calculational techniques. However, those calculations will need an extensive set of neutron cross section and thicktarget neutron yield data in order to make an accurate assessment of the risk. In this paper we briefly survey the existing neutron-production data sets that are applicable to the space radiation transport problem, and we point out how neutron production from protons is different than neutron production from heavy ions. We also make comparisons of one the heavy-ion data sets with Boltzmann-Uehling-Uhlenbeck (BUU) calculations.

Aerospace Medicine↗

A new insight into the role of "old" chemotactic peptide receptors FPR and FPRL1: down-regulation of chemokine receptors CCR5 and CXCR4.

N-formyl peptides, such as fMet-Leu-Phe (fMLP), are some of the first identified and most potent chemoattractants for phagocytic leukocytes. In addition to the bacterial peptide fMLP and the putative endogenously produced formylated peptides, we recently identified a number of other novel peptide agonists that selectively activate the prototype formyl peptide receptor (FPR) and/or its variant FPRL1. These agonists include several synthetic peptide domains derived from the envelope proteins of the human immunodeficiency virus type 1 (HIV-1) and intact human acute phase serum protein serum amyloid A. The activation of FPR and/or FPRL1 in monocytes by these agonists resulted in increased cell migration, calcium mobilisation and the heterologous down-regulation of the expression and function of chemokine receptors, notably CCR5 and CXCR4, two crucial fusion co-receptors for HIV-1. This down-regulation of CCR5 by FPR and FPRL1 agonists was associated with a rapid serine phosphorylation of CCR5. The desensitisation of CCR5 by FPR or FPRL1 agonists, not only inhibited its biological function induced by chemokine ligands, but also interfered with its capacity to act as a fusion co-receptor for monocyte tropic HIV-1. Thus, heterologous desensitisation by FPR and FPRL1 may play an important role in orchestrating the host innate immune responses which generate multiple chemotactic stimulants. Furthermore, the understanding of the structural and biochemical basis of FPR/FPRL1 activation may lead to the development of novel immunoregulatory and anti-HIV agents that emulate the process of heterologous desensitisation.

Chemotaxis, Leukocyte↗