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Biomedical subjects

Y Fang

Publications and source records attributed to Y Fang.

At least 253 records · Page 14Linked to original sources
PubMed1991

Developmental expression of cathepsin L and c-rasHa in the mouse placenta.

An investigation is described of the expression of the cysteine proteinase cathepsin L during placental development. In addition, whether cathepsin L expression is linked to c-rasHa expression in development, as it is in metastatic cells, is examined. Large amounts of cathepsin L and its transcript are present in the mouse placenta, more than six times more than in adult kidney and liver. Throughout gestation, cathepsin L and its transcript are located in the giant cells and spongiotrophoblasts of the placenta. Several forms of different mobility on denaturing gels are found in the placenta. Their apparent molecular weights, as determined from the gels, are 43,000, 39,000, 29,000, and 20,000. The 39-kDa form is procathepsin L. The 29-kDa and 20-kDa forms are lysosomal cathepsin Ls. The 39-kDa procathepsin L and the 20-kDa mature cathepsin L are the most abundant species in the placenta and are present in about equal amounts throughout gestation. At any time during gestation, placental minces synthesize and secrete only procathepsin L. The amniotic fluid of the fetus contains the 43-kDa form of cathepsin L and procathepsin L, but no detectable amounts of mature cathepsin L. By contrast, serum from nonpregnant or pregnant mice contains three forms of cathepsin L (i.e., the 43-kDa form, procathepsin L, and mature cathepsin L). Cathepsin L and the rasHa oncogene are expressed in two coincident waves corresponding to periods during which the placenta is invasive and just before parturition. The presence of large amounts of cathepsin L in the placenta suggests that the proteinase has a significant function there. Expression of cathepsin L in the placenta is potentially under the control of the ras gene product p21; both are under developmental control.

Animals↗
PubMed1991

Regulation of the expression of mitogen-regulated protein (MRP; proliferin) and cathepsin L in cultured cells and in the murine placenta.

The genes encoding mitogen-regulated protein (MRP; also called proliferin; PLF) and procathepsin L (CL; also called major excreted protein; MEP) are expressed to high levels in the mouse placenta. Although they are both regulated by epidermal growth factor (EGF) and fibroblast growth factor (FGF) in 3T3 cells, expression of these genes is differently regulated with growth state. The expression patterns of MRP and CL as a function of murine development are also different. Basal and growth factor-stimulated levels of MRP expression are much higher in growing than in quiescent 3T3 cells, whereas CL levels are similar. These changes in gene expression in cultured quiescent cells parallel the changes in MRP and CL expression observed in the late-gestational quiescent placenta. These results suggest growth factors may regulate the expression of these genes, but other influences also regulate the expression of MRP and CL in vivo.

3T3 Cells↗
PubMed1991

[Interval division, forecasting and decline tendency estimation model of malaria incidence in Xuzhou City].

This paper uses Grey Model to divide the malaria incidence of 1956-1986 into interval in Xuzhou City. The Grey forecasting GM (1,1) model is used to calculate the malaria incidence in 1987 and 1988. The accuracy of forecasting is 94.83% and 82.44% respectively. Furthermore, the Grey Verhulst model is used to fit the malaria incidence for the study of the declining tendency of vivax malaria incidence. Based on the fitting models, the decline tendency estimation models of vivax malaria are worked out.

China↗
PubMed1990

[Ecological studies on the cercariae of Echinochasmus japonicus].

Results of ecological observation on the cercariae of Echinochasmus japonicus showed that their development in and emergence from Parafossarulus striatulus as well as their activity in infecting the fish host in water were closely related to temperature and light. The number of cercariae emerged varied with the temperature of water. When the infected snails were reared at water temperature of 27-32 degrees C, the germinal cells and germ balls in the daughter radiae multiplied continually into cercariae a majority of which emerged. At water temperature below 24 degrees C, multiplication was hindered and, emergence of cercariae obviously decreased. Cercaria shedding stopped at water temperature of 14 degrees C. The reason why the rate and degree of infection with meta-cercariae of Echinochasmus japonicus in the small-sized species of fresh water fishes were higher than in the large-sized species was that the cercariae were tactic to light and so active in shallow water where they were constantly in contact with smaller fishes. Since the natural infection rate of Parafossa-rulus striatulus was found to be higher (32.2%; 37.3%) during the months of July-October than during the other months, investigations on the first intermediate host should be carried out in early autumn.

Animals↗
PubMed1989

[Electron microscopic observation of acoustic neurinoma].

The ultrastructural pattern of the acoustic neurinoma was studied with 10 excised tumors as well as one from the temporal bone. Under transmission electron microscope, the ultrastructural characteristics of the tumor were as follows: (1) The cytoplasm formed bundles of very thin, long processes in intimate contact with each other and/or with similar processes from neighboring cells. (2) All of these cells and their processes were surrounded by a basement membrane. (3) In the dense areas, the extracellular spaces were occupied by banded fusiform fibers (Luse bodies). (4) In some tumors, the extracellular space of the loose areas contained a moderate amount of collagen. (5) The extracellular space in many tumors appeared either "empty" or filled with fine granular material and small bundles of fine filaments. Fully and partially myelinated nerve fibers were found in some tumors. Pathological classification based on the ultrastructure of the acoustic neurinoma had been discussed.

Humans↗
PubMed1989

[In vivo inspection of Wallerian degeneration. MRI studies].

11 cases of infarction with Wallerian Degeneration studied by Magnetic Resonance Imaging. It showed that MR Imaging is a very useful method to inspect Wallerian degeneration in vivo after cerebral infarction and provides a new way to study neural pathways. T2-Weighted Images can demonstrate the degenerated pyramid tract and the extent of the degeneration. T1-Weighted Images can demonstrate structural changes clearly such as the atrophy of the cerebral peduncle.

Aged↗