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Biomedical subjects

Q Li

Publications and source records attributed to Q Li.

At least 1,063 records · Page 59Linked to original sources
PubMed1990

Motoneurons innervating the external anal and urethral sphincters of the female cat have different patterns of dendritic arborization.

The locations and dendritic arbors of sacral motoneurons (MNs) innervating the striated external anal and urethral sphincters (EAS and EUS, respectively) of the cat were investigated using muscle injections of cholera toxin-conjugated HRP (CT-HRP). Serial reconstructions showed that all cells labelled after EAS injections were located in the dorsomedial (DM) subdivision of Onuf's nucleus, whereas all cells labelled from the EUS were located in the ventrolateral (VL) subdivision. The dendritic arbors of EAS and EUS MNs were very different, suggesting differences in afferent control. In addition, prominent bundles of dendrites extended preferentially into the regions occupied by functionally appropriate preganglionic neurons (PGNs) in the sacral parasympathetic nucleus (SPN) which innervate the colon and bladder.

Anal Canal↗
PubMed1990

Transforming growth factor-beta 1 (TGF-beta 1) is a bifunctional immune regulator for mucosal IgA responses.

Porcine transforming growth factor-beta 1 (TGF-beta 1) exerts a unique bifunctional immunoregulatory effect on IgA responses in murine mesenteric and Peyer's patches lymphocyte cultures. TGF-beta 1 is a potent costimulator of LPS-induced IgA responses. The enhancement was observed at TGF-beta 1 at 0.1 to 10 ng/ml in both early and late phases of IgA responses from Day 5 to Day 14 in cultures. On the contrary, TGF-beta 1 exerts a profound immunosuppressive effect on IL-5-induced IgA synthesis. TGF-beta 1 is a natural cytokine produced by intestinal epithelial cells and may account for the polyclonal production and secretion of IgA at the mucosal surface and ensure the integrity of the primary host defense by mucosa-associated lymphoid tissues (MALT).

Animals↗
PubMed1990

[Effects of alpha-adrenoceptor agonists on cardiac function and blood pressure in rats].

In rat working hearts, alpha 1-adrenoceptor agonist phenylephrine increased LVP, +/- dP/dtmax, ABF and HR in the presence of propranolol. But alpha 2-adrenoceptor agonist B-HT 920 was ineffective. The changes induced by phenylephrine were antagonized by prazosin. In normotensive pithed rats, iv methoxamine dose-dependently increased LVP, +/- dP/dtmax, LVEDP, SAP and DAP. The changes in haemodynamics elicited by iv methoxamine were also antagonized by pretreatment with prazosin, and were attenuated by nifedipine (1 mg/kg, ia). In these two experiments, the increase in HR developed more slowly. The results suggest that postjunctional alpha 1-adrenoceptors, which exist in rat myocardium, produce a positive inotropic effect, which is possibly dependent on influx of extracellular calcium. Postjunctional alpha 2-adrenoceptors-mediated effects were not found in rat myocardium in our functional studies.

Adrenergic alpha-Agonists↗
PubMed1990

[Diterpenoid constituents in bulbs of Fritillaria anhuiensis S.C. Chen et S.F. Yin].

The bulb of Fritillaria anhuiensis, a substitute for the traditional Chinese medicine Beimu, has been used as antibechic and expectorant. From the either soluble part of the bulb, four constituents were isolated and identified by spectral analysis (IR, MS, 1HNMR, 13CNMR) as beta-sitosterol, daucosterol, ent-kaur-15-en-17-ol and ent-kauran-16 beta, 17-diol.

Diterpenes↗
PubMed1990

[The correlation of central projection of the acupoints riyue, qimen with correlative viscera, in the rabbit].

Twenty two rabbits were selected for the experiment and were divided into three groups. CT-HRP or CB-HRP was injected respectively into the ampulla wall (group 1) or acupoint area Riyue (group 2) or Qimen (group 3). The results obtained are as follows: Group 1. The labelled cells appeared in the spinal ganglia from T3 to T11 on the left side and T2 to T10 on the right side, and a lot appeared in the nodose ganglion of the vagus nerve on both sides. The transganglionic labeled terminals were found in the region of the solitary nucleus on both sides. A lot of labelled cells appeared in the celiae ganglia on both sides, a few dorsal motor nucleus of the vagus nerve on both sides. Group 2. The labelled cells appeared in the spinal ganglia from T4 to T10 and C6 to C8 on the same side, the anterior horn of the spinal cord from T5 to T10 segments on the same side, and a lot appeared in the ganglia of the sympathetic trunk from T3 to T10 on the same side. Group 3. The labelled cells appeared in the spinal ganglia from T4 to T8 on the same side, the anterior horn of the spinal cord from T5 to T7 segments on the same side, and a lot appeared in the ganglia of the sympathetic trunk from T4 to T8 on the same side. The results of experiment shows: 1. There are 5-7 overlapping segments of sensory nerve projection between Riyue, Qimen acupoint area and ductus choledochus ampulla.(ABSTRACT TRUNCATED AT 250 WORDS)

Acupuncture Points↗
PubMed1990

[Effect of changing the functional state of frontal cortex by GABA on the acupuncture effect of PAG neurons].

The aim of this paper is to investigate the corticofugal modulation of nucleus periaqueductal gray (PAG) after electroacupuncture by topical administration of GABA on frontal cortex. Experiments were carried out on restrained rabbits immobilized with gallamine. Electrical stimulation of the n. suralis was used as the noxious stimulation. Single unit activities of PAG neurons were record with glass microelectrodes extracellularly. "Zusanli" and "Huantiao" points were stimulated by the electroacupuncture bilaterally. GABA was applied topically by means of 3 x 3 mm2 filter paper and placed on the frontal cortex. It was shown that the responses of most PAG neurons evoked by noxious stimulation were inhibited after simple electroacupuncture. On the contrary, the acupuncture effect on PAG neurons was abolished when GABA was administered on frontal cortex. However, the effect of saline control resembled that of simple acupuncture. This result suggested that the corticofugal modulation from frontal cortex may play a role in acupuncture analgesia.

Acupuncture Analgesia↗
PubMed1990

[The changes of beta-glucuronidase in rabbit model with calcium bilirubinate stone].

The aim of the present study is to determine the beta-glucuronidase changes in bile and hepatobiliary tissue of rabbit model having pigment gallstone by means of biochemical and enzymehistochemical assay methods. The result showed both of the bacterial and non-bacterial beta-glucuronidase take part in the course of pigment gallstone formation. The bacterial beta-glucuronidase level increased quickly before the formation of gallstone, then decreased with control of bacterial infection. Non-bacterial beta-glucuronidase increased slowly in pro-formation stage of gallstone, then kept high level for long period of time. The relationship between beta-glucuronidase and pigment gallstone formation is also discussed.

Animals↗
PubMed1990

[Mutagenesis of vitamin B2 producer by using protoplasts].

Studies on preparation, regeneration and ultraviolet-mutagenesis of protoplasts of vitamin B2 producer Eremothecium aohbyii were reported. By using a complex enzyme system (0.5% snial digestase + 0.5% cellulase), a great number of protoplasts were obtained. Ultraviolet-mutagenesising positive mutation ratio is 14.29%. The HPLC analysis indicated that a lot of mutants were screened by using ultraviolet-mutagenesis mutation of protoplasts, Vitamin B2 produced by the mutant E3 increased 116.4%.

Mutation↗
PubMed1990

[The preparation and properties of catechol-1,2-dioxygenase from Pseudomonas putida].

Catechol-1,2-dioxygenase (EC 1.13.11.1) catalyzes the degradation of catechol to cis, cis-muconic acid. The biochemical properties of catechol-1,2-dioxygenase from Pseudomonas putida 84103 were investigated. The optimum pH and temperature is 7.5-8.0 and 25-30 degrees C, respectively. Cu2+, Zn2+ inhibit the enzyme activity. The paper chromatograph and UV absorption spectrum of enzymatic reaction product are accordance with those of the standard muconic acid.

Catechol 1,2-Dioxygenase↗
PubMed1990

[Study on protein polymorphism of Chinese KM subcolonies].

This paper presents the results of study on 24 protein markers by means of electrophoresis in 4KM subcolonies maintained in Beijing, Shanghai and Changcun, and compares it with that of one NIH colony introduced from U.S.A. in 1982. The results revealed that: (1) There were few genetic variants on allelic constitutions of Chinese KM mouse colonies, and the genetic distance among KM subcolonies is 0.008-0.027 positively related with the time the colony closed; (2) The unique position of S: KM mouse was shown in phylogenetic diagram of 4 KM subcolonies, which agrees with the result from mandible analysis; (3) The allelic constitutions of KM mice differs from NIH mice a Swiss derivative colony at Es-3, Es-10, Glo-1, Gpt-1, Got-2 and Mpi-1 loci and the average genetic distance between KM and NIH colonies is 0.131 + 0.011, which indicates that Chinese KM mice is one of non-Swiss derivative subspecies.

Animals↗
PubMed1990

[Studies on molluscicidal effect of bromoacetamide against Ganesella virgo].

Molluscicidal effect of bromoacetamide against the snails in laboratory and field trials were observed. Grassland of Guiliu River in Keerqinyouyiquanqi District, Neimengol Autonomous Region was selected for field trials. The results showed that bromoacetamide was fairly effective against Ganesella virgo, the intermediate host of Dicrocoelium chinensis and Eurytrema pancreaticum. In field trials, 7 days after spraying at a dosage of 0.5g/m2, 74.7-84.7% of snails were killed. When a dosage of 1g/m2 was used, the mortality of snails reached 84.8-95.7%.

Acetamides↗
PubMed1990

[Influence of iron deficiency anemia on development of thymus and spleen and adenosine deaminase activity in rats].

Models of rats with iron deficiency anemia (IDA) were established, and changes in development of the thymus and spleen and adenosine deaminase (ADA) activity in them studied. The size and weight of the thymus in IDA rats were decreased, which suggested that the development of the thymus was lowered; but the size and weight of the spleen in IDA group were increased. ADA activities of the thymus and the spleen in IDA rats were significantly decreased by 32.98% and 25.89%, respectively. One week after iron supplement, the weight of the thymus and spleen in IDS group returned to normal level (P greater than 0.05), and their ADA activity also significantly increased, but ADA activity of the thymus tissue did not return to the normal. The results suggested that the changes in ADA activity of the thymus and spleen tissues were related to iron deficiency. Stepwise regression analysis suggested that there was a negative correlation between ADA activity of the thymus tissue and FEP/Hb ratio.

Adenosine Deaminase↗