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Biomedical subjects

Z Chen

Publications and source records attributed to Z Chen.

At least 1,153 records · Page 64Linked to original sources
PubMed1996

[The effect of electroacupuncture on the discharge activity of temperature-sensitive neurons of preoptic-anterior hypothalamus in the rabbit treated by arginine vasopressin].

Arginine vasopressin (AVP) has been shown to have significant effects on the thermoregulation. The present experiments were to investigate the effect of electroacupuncture (EA) on the discharge activity of temperature-sensitive neurons of preoptic-anterior hypothalamus (PO-AH) in rabbits treated by AVP and arginine vasopressin monoclonal antibody (AVPMcAb). The results were as follows: (1) AVP could markedly promote the firing activity of EA on heat-sensitive neurons in PO-AH. (2) AVPMcAb could markedly reduce the effect of EA on temperature-sensitive neurons in PO-AH. Experimental results indicated that the mechanisms of EA on hypothermia might be related to AVP.

Animals↗
PubMed1996

[Testicular torsion: report of 12 patients].

12 cases of testicular torsion were stadieded. It is helpful to get diagnosis for early testicular torsion using radionuclide testicular imaging, B-ultrasound and color Doppler flow imaging. A peculiar type of testicular torsion was unilateral defect of radionuclide distribution. The causes, diagnoses and treatments of testicular torsion were discussed in detail.

Adolescent↗
PubMed1996

[The effect of electric acupuncture on SEP of local cerebral ischemic-reperfusion rats].

The results suggest that 3 hours after cerebral ischemia, the P1-N1 amplitudes of the somatosensory evoked potential (SEP) of the cerebral cortex decrease significantly by the stimulation of cerebrum, while the latency period of both wave P1 and P2 prolonged; 2 hours later, the abnormal data of SEP have not any improvement. These suggest that the post-ischemic cortex and subcortical neurons were injured permanently by a substantial lesions from reperfusional injuries. Cerebral tissue histologic studies show that the infarcted focus locates in caudate nucleus and lateral cortex of cerebral hemisphere. But after electric acupuncture at Huantiao at the late stage of cerebral ischemia of rats, the abnormal data of SEP show better recoveries and manintains till 2 hours after reperfusion, and even near to that of the normal rat. All of them suggest acupuncture is effective obviously for ischemic injury of cerebral tissue, and possesses a presetting protection for reperfusional injury of cerebral tissue. So it is concluded that the efficacy of acupuncture results from its comprehensive and optimal regulation function to multisystem of the whole body.

Animals↗
PubMed1996

[Relationship between body composition and serum thyroid hormone in children aged 8 to 12 years].

Eighty-one children aged 8 to 12 years were divided into three groups, i.e., obese, normal, and thin ones according to their body fat percentage, and serum thyroid hormone, zinc and copper concentrations were determined for them to study relationship between body composition and serum thyroid hormone, zinc and copper. Results indicated serum level of free 3,5,3'-triiodothyronine (FT3) was significantly higher in the obese group than in the other two groups, and that in the normal group was higher than that in the thin one. Analysis showed body fat composition correlated with serum FT3 positively. No correlation between body composition, serum thyroid hormone, and serum zinc and copper in children aged 8 to 12 years was observed in this experiment.

Adipose Tissue↗
PubMed1996

[Effects of iodine and thyroid hormone deficiency during brain development on activities of cholinergic neurone-related enzymes in central nervous system of rats].

To study the effects of iodine and thyroid hormone deficiency during brain development on activities of enzymes of central acetyl choline metabolism, activities of choline acetylcholinetransferase (CHAT) and acetylcholinesterase (AChE) in hippocampus and cerebral cortex, basal forebrain and cerebellum in 20-day-old rats were determined. Results showed that CHAT and AChE activities in hippocampus, cerebral cortex and basal forebrain in iodine deficiency and hypothyroid rats were significantly lower than those in controls. A ratio of membranebound AChE to soluble AChE, activities of inextractable AChE, and percentage of its activities in the four sections of the brain in the trial rats were significantly lower, and activities of soluble AChE and its percentage of activities were significantly higher than those in controls. It suggests iodine and thyroid hormone deficiency could affect maturation of CHAT and disturb transformation and maturation of various molecular types of AChE and delay distinctly the development of cholinergic neurone during the critical period of brain development in rats.

Acetylcholinesterase↗
PubMed1996

[The principle of nasal defects repair based on the frontal and temporal vessels anatomy].

After dissection of 9 corpes' (18 sides) vessels of the forehead, nose and temporal, we have discovered that the superatrochlear arteries run upward bilaterally, the branches of the supertrochelear arteries, the superficial branches of the supraorbital arteries and the front branches of the superficial temporal form a network--the frontal artery anastomotic net. The main trank and the parital branches of the superficial temporal arteries give off 2-3 ear branches. Based on these findings, we have made a series of explor atire researches, designed several new kinds of skin flaps for repairing the nasal defects, and improved a number traditional skin flaps. Guided by the above mentioned principles, we have successfully reconstructed 32 different kinds of nasal defects and achieved good results.

Adolescent↗
PubMed1996

[On the difference of cardiovascular effects between caudal ventrolateral medulla pressor area (cVMP) and rostrolateral medulla pressor area (rVMP)].

In 56 urethane anesthetized Wistar rats, bilateral microinjection of glutamate (L-glu) was used to observe the difference of cardiovascular effects between caudal ventrolateral medulla pressor area (cVMP) and rostral ventrolateral medulla pressor area (rVMP). The results showed that the pressor effect of cVMP was weaker than that of rVMP and was not accampanied by responses in heart rate. In the latter case, an increase of heart rate was involved. The baroreflex was inhibited when rVMP was activated by L-glu but facilitated when cVMP was activated. The above results suggest that the pathway and functions of the cardiovascular effects of rVMP are different from those of cVMP.

Animals↗
PubMed1996

[The micro-anatomy and clinical significance of the apical foramen in 1,282 permanent teeth].

To study the shape and size of the apical foramen of permanent teeth and their relations, we observed 1,282 permanent teeth. The teeth were photographed by XTL-2 photstero microscope. The rule of its shape and its clinical significance were discussed. In the 1,282 teeth, the round and oralshaped accounted for 94.77% (1,215/1,282), indicating that the morphological appearance of the apical foramen is inconsisted with that of vessels or/and nerves in the tissues.

Dentition, Permanent↗
PubMed1996

[Evaluation of ligature-induced periodontitis in minipig].

We evaluated the progressing period of ligature induced periodontitis in chinese minipig. Plaque index (PLI), bleeding index (BI), probing pocket depth (PD) and clinical attachment level (CAL) were measured in 3 minipigs. On weeks 4 and 8, there was a significant increase of the mean values of PD and CAL. After this active phase, there was no further destruction up to 20 weeks. Following ligature removed probing depths decreased in 3 weeks, but they did not restore to the baseline. It suggests that using ligature induced periodontitis model to evaluate the treatment therapy and medicine effect have to consider the self-healing of lesions, when a treatment trail is carried out in a model.

Animals↗
PubMed1996

[Omeprazole, clarithromycin and amoxicillin therapy for Helicobacter pylori infection].

The aim of this study is to determine the eradication rate in Helicobacter pylori (Hp) infection using omeprazole 20 mg twice daily, clarithromycin 500 mg twice daily and amoxicillin 1,000 mg twice daily for one or two weeks, in comparison with colloidal bismuth subcitrate 240 mg twice daily, amoxicillin 1,000 mg twice daily and metronidazole 400 mg twice daily for two weeks. 141 patients with Hp associated chronic gastritis or duodenal ulcer were randomly divided into 3 groups. Group I (n = 48) treated with triple therapy of omeprazole, clarithromycin and amoxicillin for 1 week. Group II (n = 47) treated with the same drug and dosage for 2 weeks. Group III (n = 46) treated with triple therapy of colloidal bismuth subcitrate, amoxicillin and metronidazole for 2 weeks. The Hp status was determined by rapid urease test and histology of Warthin-Starry silver stain. The eradication rates of Group I, Group II and Group III were 89.6%, 95.7% and 71.7% respectively. The difference between Group I and Group III, or Group II and Group III was significant. The difference of eradication rate between Group I and Group II was statistically insignificant. The frequency of side effects in Group III was higher than that in Group I or Group II. Although 21.1% of the patients in Group I and II experienced a metallic taste, none discontinued the medication. Our results show that triple therapy with omeprazole, clarithromycin and amoxicillin is an effective and well tolerated treatment for eradication of Hp infection and may be an alternative regimen to the old standard triple therapy.

Adult↗
PubMed1996

[Detection of severity of coronary stenosis by quantitative myocardial tomography with Tc-99m-MIBI at rest].

To evaluate the role of myocardial tomography with Tc-99m-MIBI (MB) in detecting abnormal coronary arteries, 34 patients with myocardial infarction underwent resting quantitative SPEC with MB and coronary arteriography within one month. When segmental MB uptake was < 560% of the left ventricular peak activity, there was 88% probability that a totally occluded or severely stenosed coronary artery (stenosis > 90%) was involved. There was 82% probability of finding no significant stenosis of coronary arteries in the normal myocardial segments. In the myocardial segments supplied by occluded coronary arteries, there was significantly higher MB uptake in the segments with good collateral circulation as compared with those subtended by a vessel totally occluded with poor collateral circulation (P < 0.05). The sensitivity and specificity of detecting abnormal coronary artery by quantitative analysis of myocardial tomography was 87% and 90% respectively. It is suggested that quantitative analysis of myocardial tomography with MB can differentiate between myocardial segments supplied by severely stenosed and normal coronary artery and evaluate the existence of collateral circulation.

Aged↗
PubMed1996

[Effects of reagents used in polymerase chain reaction on sensitivity and specificity of detection of Mycobacterium tuberculosis].

OBJECTIVE: To explore the effects of reagents used in polymerase chain reaction on sensitivity and specificity of detection of mycobacterium tuberculosis. METHODS: 205 tuberculosis and 105 nontuberculosis cases' sputum specimens were examined simultaneously by smear, polymerase chain reaction using three different reagents and culture. RESULTS: The positive rates of Mycobacterium tuberculosis by polymerase chain reaction using three different reagents were 82.4%, 71.7% and 61.0% respectively in 205 tuberculosis cases, while 18.0%, 11.4% and 2.8% respectively in 105 nontuberculosis cases. The differences between the above three different groups was statistically significant (P < 0.005). CONCLUSIONS: The sequences of primers and the length of amplified products of different reagents may be associated with the positive and the false positive rates of Mycobacterium tuberculosis in polymearase chain reaction.

DNA Primers↗
PubMed1996

[Water soluble contents of Chinese drug beimu, the bulbs of Fritillaria plants].

Based on platelet aggregation induced by platelet activating factor (PAF), the active fraction with inhibiting effect was screened from four species of Chinese drung Beimu, the bulbs of Fritillaria przewalskii, F. ussurienis, F. anhuiensis and F. thunbergii. According to the experimental results, the active water soluble fraction of F. ussuriensis was further studied. Two nucleosides, thymidine and adenosine were isolated. Platelet aggregation assay shows that adenosine is the chief aggregation inhibitor with 1% = 42 at 5 microns. It is suggested that nucleosides may be the other type of active constituent besides alkaloids in the Fritillaria plants.

Adenosine↗
PubMed1996

Hypoxia effects on hypothalamic corticotropin-releasing hormone and anterior pituitary cAMP.

AIM: To study the effects of acute and chronic hypoxia on hypothalamus-anterior pituitary-adrenocortex axis. METHODS: Rats and pikas were exposed to different altitude and periods. Animals were injected with CRH, Arg and NE in the third ventricle of the brain of rats. RESULTS: Anterior pituitary cAMP and plasma corticosterone levels of rats obviously increased during 1 h of hypoxia. cAMP was increased from 2.23 +/- 0.13 of control group to 7.7 +/- 0.7 of 5 km and 13.4 +/- 1.9 nmol/g wet tissue of 8 km, respectively. i.c.v. CRH, Arg and NE all activated HPA axis. The effects of CRH were most potent. CRH 2 microL 0.75 nmol i.c.v increased anterior pituitary of cAMP from 3.5 +/- 0.4 of control to 22.4 +/- 2.2 nmol/kg wet tissue. Stimulating altitude of 5000 m resulted in a 16.9% decrease in corticosterone level (P < 0.05), 8000 m resulted in a 47.5% decrease (P < 0.01) after hypoxia for 25 d. Hypoxia did not activate HPA axis in pikas. CONCLUSION: 1) Hypoxia stress activates the secretion of corticotrophin (ACTH) via cAMP; 2) Adrenocotical function of rats decays during chronic hypoxia; 3) Arg and NE regulate the secretion of plasma corticosterone and synthesis of pituitary cAMP at the hypothalamus level; 4) Hypoxia tolerance of the pika was high.

Animals↗
PubMed1995

Interleukin 12 in combination with anti-interleukin 10 reverses graft prolongation after portal venous immunization.

Portal venous pretransplantation transfusion augments allogeneic skin graft survival in mice transplanted across multiple minor histocompatibility barriers. We have shown in earlier studies that this is correlated with preferential activation for production of type-2 cytokines (interleukin [IL]-4 and IL-10) and decreased production of type-1 cytokines (IL-2 and interferon-gamma). We show that recombinant IL-12, in association with anti-IL-10 monoclonal antibody, can reverse in vivo the graft prolongation afforded by portal venous immunization and the altered cytokine production that follows. These alterations are in turn associated with increased expression of messenger RNA for interferon-gamma, IL-2, and IL-12 and decreased expression of IL-4, IL-10, and IL-13, as determined by non-quantitative polymerase chain reaction using cells obtained from lymph nodes draining the graft. Recombinant IL-12 in vitro also produces dose-related inhibition of activation for production of type-2 cytokines.

Animals↗