Biomedical subjects

G Zhong

Publications and source records attributed to G Zhong.

64 records · Page 4Linked to original sources

PubMed1992

[Ca2+ channel blocking effect of panaxadiol saponins and panaxatriol saponins of cultured cardiac cells].

It was found that PDS and PTS decreased the action potential parameters of the cultured myocardiocytes in a dosage-dependent way. The effects of PDS 1000 micrograms/ml, PTS 200 micrograms/ml were in correspondence with the known Ca2+ channel blocker Mn2+ 0.05 micrograms/ml. Washing out, administration of epinephrine 10 micrograms/ml or Ca2+ 80 micrograms/ml were able to reverse the action potential from inhibition. The above results indicate that both PDS and PTS have Ca2+ channel blockade action.

Action Potentials↗

PubMed1992

[Thixotropic properties of whole blood in children with congenital heart disease].

The thixotropic parameters of whole blood in two groups of children with congenital heart disease (CHD) were measured. Group 1. cyanotic heart disease (CCHD), 20 cases; Group 2. acyanotic heart disease (ACHD), 30 cases. Fifty healthy children were controls matched with the patients in sex and age. Their thixotropic parameters were compared; the paired t-test was used. In the children with CCHD, the hematocrit (HCT), the yield stress (tau 0) the Newtonian contribution of viscosity (mu), the equilibrium value of the structural parameter (A), the apparent viscosity at 2.37 sec-1 (eta s) and the Non-Newtonian contribution of viscosity (eta s-mu) were significantly higher than those in corresponding control groups. In the children with ACHD, only the values of tau 0, eta s-mu, and eta s were higher than those in control groups. All of the thixotropic parameters in CCHD group were significantly higher than those in ACHD group. Thus we described quantitatively CHD in terms of thixotropy of blood. The thixotropic parameters of blood could be used as indexes of severity for pathologic changes of CHD.

Adolescent↗

PubMed1991

[Research on thixotropic properties of whole blood in patients with ischemic stroke and its high risk].

So far, few papers on alteration of thixotropic properties of blood from patients with cerebrovascular disease have been found. We measured the thixotropic parameters of blood from 92 patients suffering from cerebrovascular diseases. These patients were divided into five groups. Group I consisted of 14 male patients with cerebral arteriosclerosis (CA) (aged 61.7 +/- 8.2 years) and Group II, 12 male patients with transient cerebral ischemic attack (TIA) (64.4 +/- 7.8 years). All of patients in groups III (22 male old patients, 66.6 +/- 5.1 years), IV (24 male middle-aged patients 53.7 +/- 2.8 years), and V (20 female patients 58.4 +/- 13.8 years) were suffering from cerebral thrombosis. These 92 patients and 92 selected healthy subjects were pair matched in sex and age. Using paired t-test, we compared their thixotropic parameters. The results showed that the yield stress (tau 0), the equilibrium value of the structural parameter (A), the apparent viscosity at 2.37 s-1 (eta s), and non-Newtonian contribution of viscosity (eta s-mu) in groups I, II and III were significantly higher than those in the corresponding control groups. The values of tau 0, A, eta s, (eta s-mu) and eta p of blood in group V were higher than those in the control group; only the values of tau 0, eta p, (eta s-mu) of blood in group IV were higher than those in the control group. No significant difference in the thixotropic parameters was noted among groups I, II and III. The results suggest that the patients with cerebrovascular diseases had evidently increased number and degree of RBC aggregation.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1991

[A new approach to measurement of thixotropic properties of whole human blood].

With the Low Shear 30 rheometer and its accessory instruments, four torque decay curves of whole human blood from a healthy young man were recorded at shear rate 1.285, 1.747, 2.37 and 3.23 s-1 respectively for pretesting. The modified Levenberg-Marquardt non-linear parameter estimating method was used to calculate the thixotropic parameters by following Huang's equation. The results showed that the thixotropic properties of whole human blood could be measured by recording two torque decay curves. This approach is much easier than Huang's method. We have adopted it to measure the thixotropic properties of whole blood from healthy young men (n = 32) and young women (n = 32). The results were comparable to those in Huang's reports of 1976. The coefficients of variations of most parameters in our measurement were less than those in Huang's reports. Meanwhile, we analysed the advantage in using the new method and made some suggestions to improve the measurement accuracy in human blood thixotropy.

Adolescent↗

PubMed1991

[Study on thixotropic parameters of whole blood from healthy children].

With low shear-30 rheometer, the authors used a modified protocol to measure thixotropic parameters of whole blood from 200 healthy newborns and children, so as to suggest the normal range of blood thixotropic parameters in four age groups, namely, the newborns, 1 year- group, 5 year- and 10-15 year group. The results demonstrated that the thixotropic parameters in the newborn group were higher than those in other three groups. However, these thixotropic parameters in the group 1-10 years were lower than those in the 10-15 year group. No significant sex differences were noted among the fore three groups, but sex differences appeared obviously in the 10-15 year group. It implied that the changes relying on the age is consistent with children's growth, development and physiologic activities.

Adolescent↗

PubMed1990

[The role of hemorheologic changes in the pathogenesis of acute hemorrhagic necrotizing pancreatitis].

The hemorheologic alterations were studied in experimental acute hemorrhagic necrotizing pancreatitis (AHNP) which was induced by injection of 5% sodium taurocholate into the main pancreatic duct. The results showed that during the early stage of AHNP, all of hemorheologic parameters were significantly elevated, and continually increased at the rest intervals. The authors suggested that the blood viscosity and hematocrit increase, red blood cells tend to aggregate, and erythrocyte deformation decrease are the causation of pancreatic microcirculatory disturbances and promoting pancreatic progressive necrosis. After using low molecular dextran and Salvia miltiorrhizae, the hemorheologic alterations in AHNP were recovered, and the histologic observation improved. Our data indicate the hemorheologic disturbances is one of the key factors in the pathogenesis of AHNP.

Acute Disease↗

PubMed1990

[The establishment of hemorheological data base and its applications].

This hemorheological data base was established with an Apple II computer. The covering technique was applied to deal with its lacks of memories. This data base had a mutual administration system and complete managing functions including inputting, inquiring, printing, transferring, revising functions and so on. More than twenty hemorheological parameters involving apparent viscosities of whole human blood, plasma viscosity, viscoelasticity and thixotropy indices, were saved in the way of paging mode. Meanwhile, this data base had a common mathematical statistics system in recently medical use. It included monovariable linear and nonlinear regressions, t-test, multiple linear regression, cluster analysis etc. Therefore, this data base can be conveniently utilized to analyze the hemorheological data comprehensively. Besides the establishment of normal hemorheological indices, this data base equipped a primary method of quantitative diagnosis through hemorheological indices, it gave a new method to diagnose some diseases and to observe their curing process.

Blood Viscosity↗

PubMed1990

[Visco-elasticity of whole blood in healthy young men and women].

The measurement of visco-elastic properties of blood of the Chinese is very important for theoretical research and clinical practice. This paper reports the study of the visco-elastic properties, rheological parameters and several biochemical components of the whole blood in 146 healthy young students. No significant difference in the concentrations of globulin, cholesterol, fibrinogen and blood sugar between the male group and female group could be found. The level of albumin, hemoglobin and triglyceride in the male group was significantly higher than that in the female group. The rheological measurement demonstrated that plasma viscosities in both the male and female groups had no significant differences and that the values of HCT, apparent viscosities at high (51.2 s-1) and low (0.512 s-1) shear rates and AI in the male group had higher values of ESR and OD than the female group. The visco-elastic parameters of whole blood, including eta', eta", G' and lambda, were higher in the male group than the female group. The physiological meaning of these differences between the groups is also discussed in the paper.

Adolescent↗

PubMed1986

Convergence of cutaneous, tooth pulp, visceral, neck and muscle afferents onto nociceptive and non-nociceptive neurones in trigeminal subnucleus caudalis (medullary dorsal horn) and its implications for referred pain.

Because of the likely involvement of central convergence of afferent inputs in mechanisms underlying referred pain, the activity of single neurones was recorded in the cat's trigeminal (V) subnucleus caudalis (medullary dorsal horn) to test for the presence and extent of convergent inputs to the neurones. In chloralose-anaesthetized or decerebrate unanaesthetized cats, electrical stimuli were applied to afferents supplying facial skin, oral mucosa, canine and premolar tooth pulp, laryngeal mucosa, cervical skin and muscle, and jaw and tongue muscles, and tactile and noxious mechanical and thermal stimuli were applied to skin and mucosa. Considerable proportions of caudalis neurones which could be functionally classified on the basis of their cutaneous receptive field properties as low-threshold mechanoreceptive (LTM), wide-dynamic-range (WDR), or nociceptive-specific (NS) neurones, could be excited by electrical stimulation of several of these afferent inputs. Extensive convergence of afferent inputs, including inputs from skin or mucosal areas outside the neuronal oral-facial receptive field delineated by natural stimuli, was a particular feature of the units classified as cutaneous nociceptive neurones (i.e., WDR and NS). On the basis of antidromic activation, 15% of these WDR and NS neurones were shown to have a direct projection to the contralateral thalamus. The findings question the use of terminology and classifications of somatosensory neurones based only on the cutaneous receptive field properties of the neurones since distinctions between the different neuronal populations become less obvious when properties other than those related to cutaneous afferent inputs are taken into account. Moreover, the observations of extensive convergence of different types of afferents, which was especially apparent in cutaneous nociceptive neurones, also suggest a role for these neurones in mediating deep pain and in spread and referral of pain.

Animals↗

PubMedDate not supplied

Expression of estrogen receptors ERalpha and ERbeta in endometrial hyperplasia and adenocarcinoma.

We assessed the expression of estrogen receptors (ER)alpha and ERbeta in 114 human endometrial hyperplasia and adenocarcinomas. The aim of this study was to determine the expression of both ER isoforms in human endometrial tissue by immunohistochemistry. From normal proliferation to simple and complex hyperplasia, the expression of ERalpha was increased (P < 0.05), while ERbeta did not change much (P > 0.05). In atypia hyperplasia and adenocarcinoma, both ERalpha and ERbeta were decreased significantly (P < 0.05). Most endometrial adenocarcinomas expressed ERalpha, either alone or in combination with ERbeta, and the ERbeta/ERalpha ratio was decreased when compared to normal proliferation (P < 0.05). Also, we found that the expression of ERalpha and ERbeta has no relationship with the status of lymph node of adenocarcinoma (P > 0.05). Both ERalpha and ERbeta play an important role in endometrial hyperplasia and carcinomas, the levels of ERalpha and ERbeta appear be used as prognostic indicators.

Adenocarcinoma↗