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Biomedical subjects

C H Yan

Publications and source records attributed to C H Yan.

9 recordsLinked to original sources

[Effects of methylflavonolamine hydrochloride on contractility of isolated rabbit ileum].

Methylflavonolamine hydrochloride (MFA), verapamil (Ver), and trifluoperazine (Tri) inhibited the contractions induced by submaximal concentrations of acetylcholine (ACh) and serotonin (5-HT). IC50 values (mumol.L-1) were 33.2 +/- 0.7, 0.276 +/- 0.018, 3.83 +/- 0.23, and 15.31 +/- 0.10, 0.233 +/- 0.017, 2.33 +/- 0.20, respectively. MFA, Ver, and Tri inhibited the contractions induced by CaCl2 and pD'2 values were 4.3 +/- 0.3, 6.23 +/- 0.22, 4.99 +/- 0.24, respectively. MFA 3 mumol.L-1, Ver 0.03 mumol.L-1, and Tri 3 mumol.L-1 inhibited the contractions induced by ACh in Ca(2+)-free medium, while MFA 60 mumol.L-1, Tri 30 mumol.L-1, but not Ver 0.6 mumol.L-1, had pronounced inhibitions on extracellular calcium-dependent contractions induced by ACh. These results suggest that MFA has a calcium antagonistic effect and that MFA is similar to Tri, but not Ver, in mechanism.

Animals

Spontaneous coronary artery dissection in a young man with anterior myocardial infarction.

A case of spontaneous coronary artery dissection in a young male with subsequent myocardial infarction is reported. In addition, distal vessel occlusion is noted, presumably from embolization of thrombotic material originating from the site of dissection. Postulated mechanisms of this uncommon cause of myocardial infarction and subsequent therapeutic options are reviewed.

Adult

Anticancer gelatin microspheres with multiple functions.

Biodegradable, hydrophilic gelatin microspheres (GM) with an average diameter of 70 microns were prepared by cross-linking gelatin with glutaraldehyde for hepatic intra-arterial infusion. An anticancer agent, mitomycin C (MMC), together with a radioisotope, 131I, were bound to the GM for chemotherapy and local internal radiotherapy. The 131I-labelled MMC-GM (131I-MMC-GM) could accumulate in the specific site and embolize the hepatic arteries after the hepatic intra-arterial infusion, while it caused various effects to the liver cells. The 131I-MMC-GM remained within the hepatic arteries for at least one month. In vitro release of drugs from the GM was also quantified using a dynamic dialysis method.

Animals

Direct examination of chemical kinetic laws by visual imagery. IV. Association processes between antigen- and fragmented antibody carrying fluorescent latex particles.

The binary association process was further examined by direct visual observation using a fluorescence microscope connected to an image-processing system and by a spectrophotometric method. In the present paper, we used human serum albumin (HSA)- and fragmented anti-HSA antibody-carrying fluorescent latex particles in order to attain higher sensitivities and exclude complexities that might be caused by dissociation of the association product. The rate constant of the binary association process was estimated to be 6.0 x 10(8) M-1 s-1 at 30 degrees C and pH 7.6. The activation parameters of the association process were evaluated. The effects of pH and viscosity of the suspension on the association process were also examined.

Antigen-Antibody Complex

[The significance of mummy cell in the diagnosis of Hodgkin's disease].

The mummy cell is a necrotic single cell in lympho-reticular lesion, and it is characterized by the pattern of distributing isolated in a lympho-reticular background without detachment from the surrounding cells, staining deeply or amphibic in mature both nuclei and cytoplasm and the ghost nuclei are often recognized. Totally, 95 lympho-node biopsies were reviewed, the mummy cells can be found in 21/24 of Hodgkin's disease and 18/71 of other lesions (NHL, reactive hyperplasia etc.). They are more common in nodular sclerosis (NS) and lymphocyte depletion (LD) among the four subtypes of Hodgkin's disease. It is worthwhile to note the suggestive role of mummy cells in pathological diagnosis of Hodgkin's disease.

Hodgkin Disease

[Blood gas analysis of varicocele, spermatic vein and peripheral vein].

Blood gas analysis was carried out in 80 cases of varicocele. The PO2 of the spermatic vein was lower than that of peripheral vein (P less than 0.01). There was also a significant difference of PO2 between I. and III. of varicocele (P less than 0.05). Blood of the spermatic vein showed metabolic acidosis. It is suggested that hypoxemia of the testes may affect spermatogenic function.

Adolescent