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Biomedical subjects

X Wei

Publications and source records attributed to X Wei.

212 records · Page 12Linked to original sources
PubMed1985

X-ray microanalysis of resting and stimulated rat pancreas.

The elemental distribution in acinar cells of rat pancreas was investigated by X-ray microanalysis of thin, freeze-dried cryosections. In the resting cell, the highest calcium concentrations were found in the basal part of the cell (including the endoplasmic reticulum) and in the zymogen granules. Mitochondrial calcium concentrations were low. Zymogen granules were rich in sulphur, but low in phosphorus, sodium and potassium. Stimulation of the pancreas by perfusion in vivo with the cholinergic agonist carbachol caused a significant decrease of the calcium concentration in the basal part of the cell and an increase in the calcium concentration in the apical part of the cell. The mitochondrial calcium concentration was not significantly altered. In addition, increased sodium and decreased potassium concentrations, giving rise to a significant increase in Na/K ratio were observed in all cell compartments measured, except in the zymogen granules.

Animals↗
PubMed1981

Immunofluorescence localizations of proteins in semithin 0.2--1 micron frozen sections of the ear. A report of improved techniques including gelatin encapsulation and cryoultramicrotomy.

The present work describes a high resolution technique for locating proteins in frozen sections of the inner ear by immunofluorescence. Dissected organs are encapsulated in gelatin, and sections 0.1--1 micron thick are cut at --100 degrees C in a cryoultramicrotome. These are labelled with antibodies against two cytoskeletal proteins, actin and tubulin. Actin, which had previously only been described in the sensory cells, is found in the supporting cells as well. Tubulin is identified in the supporting cells and in outer spiral nerve fibres.

Actins↗
PubMedDate not supplied

Cryoultramicrotomy as a preparative method for x-ray microanalysis in pathology.

The role of ion shifts in cell injury has become one of the most intriguing fields of application of X-ray microanalysis in pathology. In principle, cryo(ultra)-microtomy is the best preparative method for X-ray microanalysis of diffusible substances. In this review, the following points are discussed: the choice of freezing method and coolant, the use of high molecular weight polymer cryoprotectants and their possible physiological effects the choice of the cryosectioning temperature, and techniques for handling and transfer of sections. Experiences with the sectioning of cryoprotected tissue are presented. Finally, other preparative techniques for microanalysis are compared to cryoultramicrotomy.

Animals↗
PubMedDate not supplied

The reserpinized rat in the study of cystic fibrosis: x-ray microanalysis of submandibular gland and pancreas.

The chronically reserpinized rat has been suggested as an animal model for cystic fibrosis. X-ray microanalysis of thick and thin cryosections was carried out to assess elemental redistribution in the submandibular glands and the pancreas of reserpinized rats at the cellular and subcellular level. In the submandibular gland of reserpinized rats, calcium and magnesium concentrations were significantly elevated. Mucus globules, secretory granules, and endoplasmic reticulum were the primary sites of the localization of excess calcium and magnesium. A significant potassium loss from the gland had occurred, particularly from the serous cells. Electron microscopy of conventionally prepared tissue showed marked swelling of the endoplasmic reticulum, especially in mucous cells. The elemental changes in the pancreatic acinar cells of reserpinized rats were reminiscent of elemental redistribution connected with cell death: increased levels of sodium, chlorine, and calcium and decreased levels of magnesium and potassium. Ultrastructural changes included swelling of the endoplasmic reticulum and obstruction of the acinar lumen. It is concluded tha elemental redistribution in chronically reserpinized rats presents interesting parallels with cystic fibrosis.

Animals↗
PubMedDate not supplied

Polymorphism of haptoglobin, transferrin and third component of complement in subpopulations of Han ethnic group.

The genetic polymorphisms of haptoglobin, transferrin and third component of complement were investigated by electrophoretic techniques in six subgroups (Harbin, Xi'an, Chengdu, Guiyang, Zhangzhou and Lanzhou) of the Han ethnic group in China. For haptoglobin, HP*1 frequency shows a descending tendency from the South to the North in the Han ethnic group. Among the transferrin alleles, Dchi shows an increasing frequency from the North to the South. For the third component of complement, S allele is absolutely preponderant.

Asian People↗
PubMedDate not supplied

Cardiovascular effects of microinjections of thyrotropin-releasing hormone, oxytocin and other neuropeptides into the rostral ventrolateral medulla of the rat.

Thyrotropin-releasing hormone, oxytocin, neurotensin, calcitonin gene-related peptide and neuropeptide Y have been proposed as putative neurotransmitters in the rostral ventrolateral medulla of the rat. To investigate the modulation of the basal blood pressure by neuropeptides, we microinjected these neuropeptides into the rostral ventrolateral medulla of the rat and examined their effects on basal blood pressure. Male Wistar rats were anesthetized with urethane, paralyzed and artificially ventilated. Thyrotropin-releasing hormone (0.01-1 ng), oxytocin (1 and 10 ng), neurotensin (0.1-10 ng), calcitonin gene-related peptide (1 and 10 ng) and neuropeptide (1 and 10 ng) produced increases in blood pressure and/or heart rate. Ganglion blockade with hexamethonium (10 mg/kg, i.v.) blocked the pressor responses to thyrotropin-releasing hormone (0.1 ng), oxytocin (10 ng) and neurotensin (10 ng), while methylatropine (1 mg/kg, i.v.) did not affect these responses. Corticotropin-releasing factor (0.1-10 ng) and atrial natriuretic peptide (1 and 10 ng) were ineffective. These findings indicate that many neuropeptides can modify basal blood pressure when injected into the rostral ventrolateral medulla. Whether these neuropeptides play a role in the blood pressure regulation within this brain region remains to be established.

Animals↗