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Biomedical subjects

Z Han

Publications and source records attributed to Z Han.

At least 145 records · Page 8Linked to original sources
PubMed1993

[Effect of EA on the enzymes of microvasculature and CA fluorescence in acute myocardial ischemia].

It was aimed at observing the histochemical basis of physiological experiment about the effect of electroacupuncture (EA) on acute myocardial ischemia (AMI) in this paper. The capillaries of myocardium were reflected with both alkaline phosphatase (ALP) and Mg(2+)-ATPase. Thirty min after ligating the left ventricular branch (LVB), the capillaries stained by ALP were much decreased in the ischemic group without EA, while in EA group they were increased distinctly. The number and the total length of the capillaries in a 220 x 320 microns ischemic area of the posterior wall (section 10 microns) were measured and compared. In ischemic group the number was 17.2 +/- 1.65, the length was 634.62 +/- 66.24 microns, in EA group 22.5 +/- 1.44, 1187.57 +/- 103.69 microns, respectively. Both counts were significant differences (P < 0.05, P < 0.001). It reflected that EA could improve the microcirculation and metabolic function of AMI. Mg(2+)-ATPase was shown on the plasma membrane of endothelial cell of microvasculature and analysed quantitatively with a Univar scanning microspectrophotometer. After occluding LVB for 30 min its optic density of AMI was decreased to 106.83 +/- 14.06, while it was increased to 210.83 +/- 24.88 in EA group, P < 0.05. The activity of Mg(2+)-ATPase could increase in transporting Na+, k+ ions through the membrane of the endothelial cells of ischemic myocardium. The result was consistent with the physiological experiment, because EA could regulate the changes of mean repolarization rate induced by AMI and adjust the ion concentration of transmembrane. The catecholamine (CA) in myocardium was located at sympathetic adrenergic terminals with varicosities containing norepinephrine (NE).(ABSTRACT TRUNCATED AT 250 WORDS)

Alkaline Phosphatase↗
PubMed1993

[Influence of electroacupuncture on electrical activity of dorsal horn neurons of the thoracic spinal cord in the rabbit].

In the present paper, influence of electroacupuncture (EA) on electrical activity of neurons of dorsal horns of T2-T3 spinal segments was analysed in chloralose-urethane anesthetized rabbits. Results were: 1). after EA of "Neiguan" (PC 6), of the 31 dorsal horn neurons, 11 increased significantly in their firing rate, 4 decreased obviously and other 16 had no marked change; 2). after EA of "Zusanli" (ST 36), of the 28 neurons, only 2 increased significantly in firing rate, 14 decreased and other 12 had no clear change; 3). of the 6 neurons which all responded to EA of "Neiguan" (PC 6) and "Zusanli" (ST 36), 5 were excited by "Neiguan" (PC 6) and suppressed by "Zusanli (ST 36); the other one was inhibited by both; 4). the receptive field on the body surface and physiological types of 18 neurons were also examined. The results indicate that information from EA of "Neiguan" and "Zusanli" can converge to the neurons of dorsal horns of T2-T3 spinal cord, and different acupoints have a relative specificity.

Acupuncture Points↗
PubMed1993

[Influence of EA on the effective refractory period in rabbits with AMI].

A method of an incomplete ischemia of the lateral wall of the left ventricle produced by pulling the ventricular branch of the left coronary artery of rabbits was employed in this study and the dispersion of the effective refractoriness used as an index. It was noted that the effective refractory periods at the different sites in AMI region were mainly shortened and the dispersion of refractoriness increased obviously. Nevertheless, EA at Neiguan acupoint could inhibit reduction of the effective refractory of ischemic myocardium and improve the dispersion of refractoriness markedly, which would be beneficial to synchronization of the myocardial excitatory state. It suggests that EA have some effect of anti-arrhythmia.

Acupuncture Therapy↗
PubMed1993

[Anti-implantation action of nylestriol and its effect on uterine cytosol estrogen and progesterone receptor in rabbits].

The anti-implantation action of nylestriol in rabbit was studied. The changes of uterine cytosol estrogen and progesterone receptor (ER and PR) were analysed with the dextran-coated charcoal method. Plasma progesterone level of early pregnant rabbits was measured by radioimmunoassay. The results showed that oral nylestriol could obviously prevent the early pregnancy of rabbit by anti-implantation of blastocyst. The content of ER decreased in the nylestriol group (P < 0.01). The content of PR in nylestriol group was lower than that of the control group (P < 0.05). No significant difference of plasma progesterone level was noted between the control and treatment groups. These results suggest that there is close relationship between the anti-implantation effect of nylestriol and the decreased content of cytosol ER and PR during the pre-implantation period.

Animals↗
PubMed1993

Proliferation of nontransformed cells is inhibited by adenosine metabolite of but not by parental 8-Cl-cyclic AMP.

In this study we evaluated the regulatory effect of 8-Cl-cyclic AMP (cAMP) on the proliferation of nontransformed cells. Our data indicate that similar to the reported inhibitory effect of 8-Cl-cAMP on the proliferation of Molt-4 lymphoma cells, the inhibitory effect of 8-Cl-cAMP on the proliferation of nontransformed fibroblast, myoblast and endothelial cells was dependent on serum or cyclic nucleotide phosphodiesterases and other nucleotide phosphatases. This suggested that the metabolism of 8-Cl-cAMP was required for the inhibition of cell proliferation. In addition, this serum-dependent inhibitory effect of 8-Cl-cAMP was antagonized by the presence of exogenous adenosine deaminase, suggesting that 8-Cl-adenosine was responsible for mediating the serum-dependent inhibitory effect of 8-Cl-cAMP on these cells. This idea was supported further by the ability of 8-Cl-adenosine to duplicate the inhibitory effect of 8-Cl-cAMP on cell proliferation in defined medium.

2-Chloroadenosine↗
PubMed1992

Influence of acupuncture on the discharge of PHA neurons in the rabbit.

This paper deals with whether the posterior hypothalamus area (PHA) can receive signals from electroacupuncture (EA) at "Neiguan", and whether a relative specificity does exist between acupoints or acupoint and non-acupoint. The neuron activity was recorded extracellularly for analyzing the influence of EA at different acupoints and non-acupoint on the discharge of PHA neurons.

Acupuncture Points↗
PubMed1991

The deleterious effects of aging and kainic acid may be selective for similar striatal neuronal populations.

The present experiments were performed to determine whether the age-related loss of striatal D2 receptors could be localized to a kainic acid-sensitive neuronal population. This neurotoxin selectively destroys intrinsic neurons. Thus, if kainic acid reduced striatal D2 receptor concentrations such that age differences in this parameter were no longer observed, it would be a good indication that the D2 receptors lost through aging are also sensitive to kainic acid. Mature (6 months) and senescent (24 months) rats were stereotaxically, unilaterally injected with 3 micrograms/0.5 microliter kainic acid into the right striatum. Seven days later striatal D2 receptors were assessed with [3H]-spiperone in one group of mature and senescent rats. A second group of mature and senescent unilaterally lesioned rats was anesthetized and perfused. Brains were dissected and processed for striatal cell counts using cresyl violet staining, tyrosine hydroxylase and met-enkephalin using immunocytochemistry, and acetylcholinesterase using histochemistry. Age-related differences in D2-receptor concentrations were observed in intact, but not lesioned, striata. Kainic acid was less effective in reducing D2-receptor concentrations in senescent animals, suggesting that some proportion of the receptors was already lost prior to lesioning. Kainic acid also reduced total neuronal numbers, as well as Met-Enk and AChE positive staining, to approximately the same extent in mature and senescent rats. No age differences were seen in any of the other parameters following kainic acid administration.

Acetylcholinesterase↗
PubMed1991

[Preliminary study of cervicovaginal peroxidase as indicator for ovulation].

The study was designed to determine whether the change in the pattern of cervicovaginal peroxidase activity in the fertile period of women can serve as a basis for the development of a technique to predict ovulation time in natural family planning. Eight healthy women volunteered for this study in Chengdu area. The samples of cervical mucus and vaginal secretion were collected. The specific G-Px activity was measured with reference to the procedure of Tsibris, et al., on days 6, 8, 10, 12 through 16, 18, 20, 22, 24 of each menstrual cycle; at the same time an antecubital venous blood sample was drawn to be analyzed for levels of LH, FSH, E2, and P by RIA. The data showed that in 7 ovulatory cycles the G-Px activity did not vary regularly in vaginal secretion but it did drop rapidly in cervical mucus 2 or 3 days before ovulation time and it rose again one day after ovulation. The results suggest that the measurement of the G-Px activity in cervical mucus can be used to predict ovulation by two to three days before the time.

Cervix Mucus↗
PubMed1991

[Intrauterine adhesion and ovulatory disorder following induced abortion].

Follicular stimulating hormone, luteinizing hormone, prolactin, estradiol and progesterone were measured by radioimmunoassay in 34 patients with those from 34 normal cycling women after induced abortion. The result showed that the anovulatory incidence of the patients (20.6%) was significantly higher than that of the controls (2.8%) (P less than 0.05). Increased prolactin and premature ovarian failure might be responsible for the anovulatory disorder, resulting in unsatisfactory restoration of fertility. It is suggested that the low success rate in treating patients with intrauterine adhesion after induced abortion may be due to premature ovarian failure and hyperprolactinaemia.

Abortion, Induced↗
PubMed1991

Role of amygdaloid nucleus in the correlation between the heart and the acupoint neiguan in rabbits.

Amygdaloid nucleus (AMYG) could converge and integrate the signals from electroacupuncture (EA) at Neiguan (P 6) and acute myocardial ischemia (AMI) in rabbits. And EA could regulate the changes in the discharge of single units in AMYG caused by AMI, that is, EA inhibited the increased frequency, and reversed the decreased frequency. This suggested that AMYG is an important link in correlation between the heart and the acupoint Neiguan, providing an experimental basis for the Theory of Channel--Viscera Correlation.

Acupuncture Points↗
PubMed1990

Transference of thoracodorsal nerve to musculocutaneous or axillary nerve in old traumatic injury.

On the basis of anatomic studies, we have devised a new method of transferring the thoracodorsal nerve to reinnervate the paralytic deltoid or biceps muscles in an old traumatic injury of the associated nerve. It has been applied to a case of musculocutaneous nerve injury and two cases of axillary nerve injury with good results. The muscle functions have returned to normal within 1 and 2 years, respectively, as shown by electromyography and the muscular contractility test.

Adult↗
PubMed1990

[Studies on the interrelationships between some acupoints on pericardial channel and heart].

The theory of acupoint-Zangfu correlation is one of the essential contents of the doctrine of Channel and Collateral. Being based on this theory, a study has been done from the experimental research point of view in our laboratory since 1979, to approach the specific interrelationships between some acupoints on the pericardial channel and heart, as well as their functional regularities, and has served for clinical practice, which provided the basis for the research on the connective pathways between the pericardial channel and heart. Coronary heart disease, one has been treated effectively by acupuncture, was selected and, by imitating the early stage of myocardial infarction, the reperfusion model of coronary artery in rabbits was designed to produce a reversible acute myocardial ischemic injury. As the indices, the ST segments of second standard lead and augmented unipolar limb leads of electrocardiogram were obviously improved when electroacupuncture (EA) was applied to the points "Jianshi" or "Neiguan", these could be observed repeatedly. Then the factors influencing the effects of acupuncture were analysed. The effects of EA at six points on "pericardial channel", "urinary bladder channel" and "liver channel" were compared. Results showed that both "Ximen" and "Weishu" were able to accelerate the restoration of acute myocardial ischemic injury. However, EA at "Zhongdu" and "Xiguan" could hardly affect, this indicates that "where the channel passes through, where it affects on".(ABSTRACT TRUNCATED AT 250 WORDS)

Acupuncture Points↗
PubMed1990

Influence of EA on the electrical conductance in the marginal area of the acute ischemic myocardium in the rabbit.

AMI was produced by occlusion of LVB for 30 min in the rabbit, lengthening the conductive time of myocardium in the ischemic area and resulting in asynchronous activation state of myocardium. EA could facilitate the conductance of electric activation in the ischemic marginal area and make the activation of myocardial cells in this area synchronous which is of importance in blocking the formation of reentrant circuit. The finding suggests that EA possesses an antiarrhythmic effect.

Action Potentials↗
PubMed1990

Relationship between PO-AH and PHA in the effects of EA at neiguan in the rabbit.

The activity of PHA neurons was extracellularly recorded by using glass microelectrodes and the mutual relationship between PO-AH and PHA during the regulation activity of EA was analysed. The results were as follows: 1. The activity of most PHA neurons could be changed by PO-AH stimulation. 2. The activity of some PHA neurons could be affected by AMI. 3. The AMI-induced PHA neurons activity could be changed by EA at "Neiguan". 4. The effect of EA could be enhanced in some PHA neurons by PO-AH stimulation under EA. The findings suggest that PO-AH and PHA possess some coordination effect in the regulation of EA at "Neiguan" on the functional activity of the heart.

Acupuncture Points↗
PubMed1989

Effect of aging on concentrations of D2-receptor-containing neurons in the rat striatum.

Striatal D2 dopamine receptor concentrations were shown to decrease 30-35% during the lifespan of Wistar rats as assessed both radiochemically and autoradiographically. Binding densities and degree of age-change varied within the striatum; the latter ranging from 17 to 44% in 4 different regions. Overall neuronal loss during aging was 19%, and also varied considerably within the different striatal regions. Thus, it appears that neuronal loss may account for up to roughly half of the striatal D2 receptor loss during aging.

Aging↗
PubMed1989

Effect of aging on populations of estrogen receptor-containing cells in the rat uterus.

Estrogen receptor-containing cells were identified in uteri of mature and senescent rats by means of quantitative autoradiography. Cell numbers and density were assessed in the various uterine layers. It was determined that despite decreases in receptor concentrations in endometrium, endometrial stroma, myometrium, and epithelium, no significant cell loss occurred in any region. Receptor content per cell clearly decreased with age in the endometrial stroma, while only in the myometrium was there any suggestion of cell loss in the absence of receptor loss from individual cells. Thus, age-related reductions in uterine estradiol receptor levels may be due to different mechanisms in different tissue regions.

Aging↗
PubMed1987

An E. coli promoter induced by the cessation of growth.

The production of the bacterial DNA replication inhibitor Microcin B17 is induced as cultures enter stationary phase. Using S1 nuclease protection assays we have shown that this induction is the result of increased levels of transcription initiation from a promoter located upstream from mcbA, the structural gene for Microcin B17. Upstream from the start site of transcription there is a rather typical -35 region. However, there is no good homology to the consensus -10 region. While most of the cell's transcription is shut off as a result of the cessation of growth, transcription from the mcbA promoter continues for several hours in stationary phase. A single-copy gene fusion between mcbA and lacZ was used to monitor the response of the promoter to different nutritional conditions and in different host backgrounds altered in metabolic regulatory loci. Starvation for nitrogen, phosphate or carbon sources all induced transcription from the promoter. Levels of transcription were reduced in ompR backgrounds. In contrast, mutations in other global regulatory loci, fnr, relA and cya had little or no effect.

Anti-Bacterial Agents↗