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Biomedical subjects

J Xu

Publications and source records attributed to J Xu.

At least 1,279 records · Page 71Linked to original sources
PubMed1989

[Influence of acupuncture on human nasal mucociliary transport].

The effect of acupuncture on human nasal mucociliary transport was studied by using both 99mTc tagged-particle method (detected by SPECT) and the saccharin method. Results showed that acupuncture on the Yingxiang and Hegu could increase the velocity of the mucociliary transport in chronic rhinitis patients, but not in normal persons.

Acupuncture Therapy↗
PubMed1988

Histochemistry and electron microscopy in the diagnosis of small mucous cells in carcinoma of the stomach.

One hundred and two cases of poorly differentiated adenocarcinoma were obtained from 71 surgical and 31 biopsy specimens of the stomach. These tumours produced both intracellular and extracellular mucins, which were demonstrated to be neutral mucins, N-acetyl sialomucins, sulphomucins and O-acetyl sialomucins. The majority of tumours (85.3%) secreted two or more kinds of mucins simultaneously, but only a small proportion (14.7%) produced a single kind of mucin. Ultrastructurally, three types of mucin granules were identified; these differed in shape and density. Tumour cells containing intracellular mucins or mucin granules were designated as mucous cancer cells and further subdivided into small, large and goblet mucous cells; tumour cells having neither mucins nor glandular differentiation were designated as undifferentiated cancer cells. These histochemical distinctions, supported by the electron microscopical observations, may be useful to demonstrate early malignant foci in gastric biopsies.

Adenocarcinoma↗
PubMed1987

Serotonergic, adrenergic and histaminergic receptors coupled to phospholipase C in cultured cerebellar granule cells of rats.

Phosphatidylinositol (Ptdlns) turnover has been studied in the primary culture of granule cells dissociated from the cerebellum of postnatal rat. Addition of serotonin (5-hydroxytryptamine, 5-HT) caused an increase (300-600% of control) of [3H]inositol monophosphate (IP1) accumulation in the presence of LiCl in cells prelabeled with [3H]myo-inositol. The EC50 and saturation concentrations of 5-HT were about 0.1 and 10 microM respectively. Some nonselective 5-HT receptor agonists, MK212, 5-methoxytryptamine, tryptamine and quipazine, were capable of stimulating IP1 accumulation; a selective 5-HT1A receptor agonist, 8-OH-DPAT, was ineffective. The 5-HT-induced response was potently blocked by several 5-HT2 receptor antagonists such as ketanserin, mianserin, spiroperidol and pyzotyline. The 5-HT-induced accumulation was dependent on the culturing time of granule cells with the maximal response seen in an 8-day culture. Norepinephrine (NE) also promoted an increased IP1 accumulation (300% of the control) with an EC50 of about 1 microM, while prazosin inhibited this NE-induced response with a Ki of about 0.2 nM. The responses induced by NE and 5-HT appeared to be additive. In addition, histamine in a dose-dependent manner enhanced the accumulation by about 100%; this histamine effect was blocked by triprolidine, an H1 receptor antagonist, but not by cimetidine, an H2 receptor antagonist. These results suggest that 5-HT, NE and histamine could be part of the neurotransmitter substances present in mossy fibers or other afferent nerve endings which innervate granule cells in vivo and that Ptdlns turnover regulated by their selective receptors on granule cells may play a role in modulating the excitatory function of these neurons.

Animals↗
PubMed1987

Mutagenicity of diesel exhaust particles and oil shale particles dispersed in lecithin surfactant.

Diesel exhaust particulate material from exhaust pipe scrapings of two trucks, diluted automobile diesel exhaust particulate material collected on filters, and two oil shale ores were prepared for the Ames mutagenicity assay by dichloromethane (DCM) extraction, by dispersion into 0.85% saline, or by dispersion into dipalmitoyl lecithin (DPL) emulsion in saline. Salmonella typhimurium TA98 was used to detect frameshift mutagens in the samples. Samples of diesel soot gave positive mutagenic responses with both DCM extraction and DPL dispersion, with the DPL dispersion giving higher results in some cases. The results suggest that possible mutagens associated with inhaled particles may be dispersed or solubilized into the phospholipid component of pulmonary surfactant and become active in such a phase.

Dimyristoylphosphatidylcholine↗
PubMed1987

Muscarinic acetylcholine receptor-mediated phosphoinositide turnover in cultured cerebellar granule cells: desensitization by receptor agonists.

Cultured granule cells prepared from 8-day postnatal rats were used for the study of carbachol-induced phosphoinositide turnover. The addition of carbachol induced a 20- to 30-fold increase in [3H]inositol monophosphate (IP1) accumulation within 30 min in the presence of 20 mM LiCl in granule cells prelabeled with [3H]myoinositol. Carbachol also stimulated the formation of [3H]inositol bisphosphate and [3H]inositol trisphosphate assayed either in the presence or in the absence of lithium; the increase in [3H]inositol triphosphate and [3H]inositol biphosphate synthesis appeared to be faster in the time course but much smaller in amount when compared with the formation of [3H]IP1. The EC50 of carbachol was approximately 7 microM, and the saturation concentration was about 100 microM. This carbachol-induced response was completely blocked by two muscarinic acetylcholine receptor (mAChR) antagonists, atropine and pirenzepine, with a Ki of 0.5 and 120 nM, respectively. Saturation studies of the binding of [3H]N-methylscopolamine and [3H]quinuclidinyl benzilate to mAChRs in intact granule cells revealed the presence of a single class of binding sites with a Kd of 140 and 126 pM, respectively, and a Bmax of approximately 70 fmol/10(6) cells for both ligands. Within 1 hr after pre-exposure of cells to carbachol, the subsequent carbachol-induced [3H]IP1 accumulation was reduced by about 50%, whereas mAChR binding, assessed by using either [3H]N-methylscopolamine or [3H]quinuclidinyl benzilate, was unchanged. A second slower phase of desensitization was associated with a loss of mAChR binding sites; at 18 hr, the decrease of responsiveness was about 80%, whereas the loss of mAChR sites was about 60%.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Sulphomucin colonic type intestinal metaplasia and carcinoma in the stomach. A histochemical study of 115 cases obtained by biopsy.

One hundred fifteen gastroscopic biopsy specimens (54 cases of carcinoma and 61 of gastritis) were used in this histochemical study. Intestinal metaplasia (IM) was classified into small intestinal type (ST) and colonic type (CT). The former may be a reactive change only. The incidence of sulphomucin colonic type (SCT) metaplasia was higher in gastric carcinomas than in benign lesions (P less than 0.01), and a relation between SCT metaplasia and cancer was demonstrated by both histologic and histochemical procedures. This suggests that SCT IM is correlated with certain precancerous lesions. There was no significant difference in the incidence of O-acetyl sialomucin colonic type (OCT) metaplasia between benign and malignant diseases. Further study is needed to determine why slightly more than half of the SCT IM was accompanied by OCT IM.

Biopsy↗