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Biomedical subjects

X J Fan

Publications and source records attributed to X J Fan.

26 records · Page 2Linked to original sources
PubMed1986

[Photodynamic therapy (PDT) of bladder cancer in the rat].

PDT of rat bladder cancer, induced by N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN) was studied. All animals were divided at random into three groups. Group 2 and 3 were treated by hematoporphyrin derivative (HPD)-laser PDT while group 1, without treatment, served as control. The results showed that the malignant lesions could be selectively and obviously destroyed, if the whole tumor area were sufficiently exposed to the laser irradiation. However, the normal bladder epithelium and muscle layer showed no histologic change. Similar reactions were found in papilloma of bladder which was considered as precancerous lesion. Thus, PDT may be beneficial to cancer prevention. Its role in prevention and treatment of bladder cancer should be further studied experimentally and clinically.

Animals↗
PubMed1985

The biological effects of photodynamic therapy on normal skin in mice--I. A light microscopic study.

A light microscopic investigation of the biological effects of photodynamic therapy using hematoporphyrin derivative and red light irradiation has been carried out. HpD alone, even used at a dose of 50 mg/kg, did not cause histologically discernible changes. The irradiation alone used in this experiment caused only slight or moderate dilatation and congestion of blood vessels, which disappeared completely within several hours after light exposure. In the PDT treated mouse ears severe degeneration and necrosis of skin tissue occurred within 1-2 days. The importance of adequate drug and light doses and proper interval chosen for obtaining best therapeutic effects and protection of surrounding normal tissues was pointed out. The possible mechanism of the PDT action in vivo was briefly discussed.

Animals↗
PubMed1985

The biological effects of photodynamic therapy on normal skin in mice--II. An electron microscopic study.

In the present study it has been demonstrated that the ultrastructural changes in mouse ear skin after PDT action occurred much more distinct and earlier than those observed in the histological study. Various types of cells in the skin respond to the photodynamic action differently. The endothelial cells, fibroblasts and nerve fibers are most sensitive. In contrast, the keratinocytes and chondrocytes often remain rather well preserved after PDT treatment. The possible mechanism of PDT action was briefly discussed.

Animals↗
PubMedDate not supplied

Enhanced T-helper 2 lymphocyte responses: immune mechanism of Helicobacter pylori infection.

Several lines of evidence implicate Helicobacter pylori (H. pylori) infection in gastroduodenal inflammation. However, the exact pathogenesis of H. pylori infection is not fully understood. T-helper (TH) lymphocytes may be subdivided into TH1 and TH2 cells based on the distinct patterns of cytokine production. TH1 reaction is associated with immunity or resistance to infection, while TH2 reaction is associated with the progression or persistence of infection. The production of interferon-gamma (INF-gamma) and interleukin 2 (IL-2), which are type 1 cytokines, is decreased in H. pylori infection. Enhanced production of type 2 cytokines (IL-4) and IL-6) is observed in individuals with H. pylori infection. Suppressed proliferative responses of peripheral blood and gastric lymphocytes have also been demonstrated in patients with H. pylori colonisation, suggesting that specific T-cell responses may be down-regulated by an enhanced TH2 reaction. Suppressed TH1 and enhanced TH2 responses in H. pylori infection may be involved in the immunopathogenesis of chronic H. pylori infection.

Chronic Disease↗