Biomedical subjects

Z J Liang

Publications and source records attributed to Z J Liang.

At least 19 recordsLinked to original sources

PubMed2004

A comparative study of 632.8 and 532 nm laser irradiation on some rheological factors in human blood in vitro.

The effects of laser irradiation with 632.8 and 532 nm on rheological properties of blood were comparatively studied in vitro. Under the irradiation condition of 30 mW, laser irradiation of blood samples using a spot diameter of 5 mm with each laser, showed promising results in the modulation of hemorheological properties. When blood samples from patients with abnormally high values of erythrocyte sedimentation rate (ESR) were irradiated, the values of ESR were lowered statistically by either of the 632.8 or 532 nm lasers. The laser irradiation reduced blood viscosities at different shear rates (10-110 S(-1)) for the hyper-viscosity blood samples. Laser irradiation increased the electrophoretic mobility (EPM) of erythrocytes when the values of the sample's EPM were abnormally slow. The erythrocyte deformability was enhanced by laser irradiation when the deformability of the sample from the patients was originally poor. For verifying the improvement of laser irradiation on erythrocyte deformability, the typical erythrocyte samples with poor deformability were produced by the pre-treatment of the erythrocytes with Ca(2+). The deformability of these erythrocyte samples was also improved after laser irradiation. These results suggest that membrane-bound hemoglobin (Hbm) might be the initial site of the interaction, since Hbm is the main cause of poor deformability when erythrocytes were treated with Ca(2+). In all experiments including ESR, blood viscosity, EPM and erythrocyte deformability, the 532 nm laser demonstrated more efficient effects on modulating rheological properties than 632.8 nm laser. This wavelength effect is consistent with the absorption spectrum of hemoglobin, reflecting that hemoglobin may be one of the action targets under laser irradiation.

Blood↗

PubMed2000

Effects of Veratrum nigrum alkaloids on central catecholaminergic neurons of renal hypertensive rats.

AIM: To study the central hypotensive mechanism of Veratrum nigrum L var ussurience Nakai alkaloids (VnA) in renal hypertensive rats(RHR). METHODS: The quantitative method of immunocytochemistry (ICC) was used to observe and detect the effect of VnA (30 micrograms.kg-1, i.v.) on activity of central catecholaminergic (CA) neurons of C1, C2, A1, and A5 areas in RHR. RESULTS: VnA increased the immunoreactivity (IR) of tyrosine 3-monooxygenase (TM)-immunopositive (IP) neurons of C1, C2, and A5 areas in RHR experimental group compared with RHR control group [positive units: (1.9 +/- 0.4), (1.18 +/- 0.23), (1.2 +/- 0.4) vs (0.15 +/- 0.22), (0.31 +/- 0.16), (0.69 +/- 0.20), respectively]; IR of TM-IP neurons of C1 and C2 areas in RHR control group was decreased compared with sham-operated group [positive units: (0.15 +/- 0.22), (0.31 +/- 0.16) vs (1.45 +/- 0.29), (1.36 +/- 0.25), respectively]. CONCLUSION: VnA increased the activity of central CA neurons in RHR to exert its hypotensive effect.

Animals↗

PubMed1999

[Compression of the palmar cutaneous branch of the median nerve at the wrist].

OBJECTIVE: To study the compression factor and clinical manifestation of the compression of the palmar cutaneous branch of the median nerve. METHODS: Anatomic study was done on both sides of 2 cadavers and 6 cases of hand injury in the debridement, the origin, course, branch of the palmar cutaneous branch of the median nerve were observed. From 1995 to 1998, 12 patients of compression of the palmar cutaneous branch were treated by local blockade injection. Among them, there were 8 males and 4 females, aged from 23 to 65 years and the course of disease ranged 3 to 12 months. RESULTS: The palmar cutaneous branch of the median nerve was (1.3 +/- 0.1) mm in diameter, it could be pulled when the wrist dorsi-extension. All cases showed good recovery of hand function and no recurrence after 4 to 12 months follow-up. CONCLUSION: The palmar cutaneous branch compression syndrome is closely related to the local anatomy. The diagnosis is definite according to the clinical symptoms and signs, and local blocking is effective on the most patients.

Adult↗

PubMed1997

Physiological basis for long life span.

A collection of clinical data is reported on nonagenarians in comparison to an 'average' population of younger age. The results of these clinical data indicated that a vital physiological basis for long life span probably existed. The basis include a better micro-blood-flow state, a better cardiac, immune (nature killer cell activity), adrenocortical, hepatic and renal function, and a higher level of high density lipoprotein cholesterol. It is suggested that the method, including Chinese traditional medicine, to improve the micro-blood-flow, nature killer cell activity, high density lipoprotein cholesterol and vital organ function may be beneficial for life preservation and aging retarding.

Aged↗

PubMed1997

Inhibitory effects of vinpocetine on sodium current in rat cardiomyocytes.

AIM: To study the effects of vinpocetine (Vin) on the sodium current (INa) in cardiomyocytes. METHODS: The sodium current in adult rat ventricular myocytes was measured by whole cell patch-clamp technique. RESULTS: The INa in cardiomyocytes was blocked reversibly by Vin, in concentration-dependent and voltage-dependent manner, but not rate- or use-dependent. The INa was attenuated by 13%-75% when the Vin concentration was raised from 10 to 80 mumol.L-1. The IC50 (95% confidence limits) was 36.4 (28.1-47.1) mumol.L-1. When the membrane potential depolarized over the range of -90 mV to +40 mV in 10-mV step, inhibitory effect of Vin on the INa was 39% at first, then maintained at a higher level, about 52% +/- 5%. The maximal depression (57%) reached at about 0 mV. Vin influenced both the activation and inactivation processes of sodium channel, and resulted in attenuation of the window currents (the slowly inactivating sodium currents). CONCLUSION: Vin inhibited sodium currents in rat ventricular myocytes.

Animals↗

PubMed1995

[Effect of acute hypoxia on blood viscosity, red blood cell deformability and the left ventricular function in rats].

Experiments were performed on SD rats anaesthetized with urethane and chloralose. The left ventricular function and the parameters of hemorrheology during acute hypoxia were investigated. It was found that during acute hypoxia of 15 min, arterial blood gas value PaO2 decreased markedly. The parameters of the left ventricular function such as +/- dP/dtmax, Peak, HR, Vce40, Vmp, Vmax, L0 (CFU), decreased markedly either. At the same time, hyperviscosity was induced and red blood cell filtration (IF) increased. All these parameters recovered to normal control level after reoxygenation of 15 min. By intravenous injection of propranolol (0.5 mg/kg) and then hypoxia, the left ventricular function were suppressed markedly; and so were to the elevation of blood viscosity and IF. Preinjection of regitine (3 mg/kg) prior hypoxia has the same effect on the blood viscosity and IF. Acute hypoxia induced hyperviscosity and elevation of IF could be suppressed by destruction of carotid sinus region with phenol, but the left ventricular function decreased markedly. These results suggest that acute hypoxia induces hyperviscosity and decreases of red blood cell deformability and left ventricular function, which is probably mediated via the sympathetic nervous system and carotid sinus region.

Animals↗

PubMed1995

Inhibitory effects of 2-[(diethylamino)acetyl]-1,2,3,4-tetrahydro-6, 7-dimethoxyl-1-[1'-(6"-methoxy-2"-naphthalenyl)ethyl]-isoquinoline on isolated guinea pig papillary muscle and heart atrium.

AIM: To investigate the cardiac actions of 2-[(diethylamino)acetyl]-1,2,3,4-tetrahydro-6, 7-dimethoxyl-1-[1'-(6"-methoxy-2"-naphthalenyl) ethyl]-isoquinoline (CPU57) by comparison with nifedipine and focus on its mechanism of actions. METHOD: The following were measured and recorded: 1) the rate and contraction of spontaneous beating of the guinea pigs right heart atrium, 2) the isometric tension of the electrically stimulated left heart atrium and the right papillary muscles. RESULTS: CPU57 had negative inotropic and negative chronotropic actions in isolated heart of guinea pigs as the typical calcium antagonist, nifedipine. However, CPU57 0.01-100 mumol.L(-1) produced less cardiac inhibitory potency than nifedipine and had much stronger negative inotropic action than negative chronotropic action. The decrease in external CaCl2 concentration from 1.5 to 0.3 mmol.L(-1) or increase to 7.5 mmol.L(-1), potentiated or reduced respectively, the inhibitory action of CPU57 on the contraction in paced left heart atrium in normal CaCl2 solution. CPU57 1-10 mumol.L(-1) also inhibited contractile response to CaCl2 in paced left heart atrium with pD2' value of 4.77. CONCLUSION: CPU57 has calcium antagonism on the heart of guinea pigs.

Animals↗

PubMed1993

Cardiac electric activity of 1-(2-[(6-methoxyl)-naphthylmethyl])-1-methyl-N-piperidinylacethyl-6,7- dimethoxyl-1,2,3,4-tetrahydroisoquinoline in SHR and WKY rats.

1-(2-[(6-Methoxyl)-naphthylmethyl)])-1-methyl-N-piperidinylacethyl -6,7- dimethoxyl-1,2,3,4-tetrahydroisoquinoline (CPU-23), a substituted tetrahydroisoquinoline, reduced the voltages of P wave and J point, prolonged PR interval, and slowed sinus rhythm of ECG in spontaneously hypertensive rats (SHR) and age-matched normotensive WKY rats. The effects of CPU-23 on cardiac electric activity were stronger in SHR than in WKY rats (P < 0.05 or P < 0.01). The results suggest that CPU-23 have a calcium antagonistic activity on rat hearts and that calcium antagonists may exert a stronger inhibition of the cardiac electric activity in hypertensive rats than in normotensive rats.

Animals↗

PubMed1993

[Inhibitory effect of intraventricular administration of morphine on the hyperviscosity and elevation of blood pressure induced by stress in the rat].

Experiments were performed on 99 Wistar rats. It was found that hyperviscosity and elevation of blood pressure (BP) could be induced by hanging and restraining conscious rats with their four limbs tied on a frame. These effects were unaffected by bilateral vagotomy. By intravenous injection of propranolol or phentolamine, elevation of BP could be reduced, while stress-induced hyperviscosity could only be reduced by propranolol (i.v.). Stress-induced hyperviscosity and elevation of BP could be inhibited by electroacupuncture applied to the right hind leg or microinjection of morphine into 4th ventricle of the brain. On the other hand, if opiate receptor antagonist naloxone was given into the 4th-ventricle, the stress-induced hyperviscosity and elevation of BP could no longer be inhibited by electroacupuncture. It is suggested that the hyperviscosity and elevation of BP induced by hanging and restraining are mediated by excitatory cardiovascular sympathetic outflow with the result of activation of adrenoreceptors. Activation of the opiate receptors in the hindbrain may be responsible for decrease in stress-induced hyperviscosity and elevation of BP and for the inhibitory effect of electroacupuncture of the right hind leg on stress-induced hyperviscosity and elevation of BP.

Animals↗

PubMed1992

[Effects of tetramethylpyrazine and ferulic acid alone or combined on vascular smooth muscle, blood viscosity and toxicity].

The experiments showed that both tetramethylpyrazine and ferulic acid relaxed the norepinephrine-induced spasmodic contraction of rabbit and rat aorta strips, increased the coronary flow of isolated guinea pig hearts and reduced the whole blood viscosity in rats. Evaluated with Burgi's equation, the combined effect of these 2 drugs was obviously potentiated, but the combined acute toxicity in mice was greatly reduced.

Animals↗

PubMed1992

[Microinjection of 5-HT into the rostral ventrolateral medulla reduced the hyperviscosity and elevation of blood pressure induced by stress].

Experiments were carried out on 62 wistar rats. The hyperviscosity and elevation of blood pressure were induced by hanging and restraining the rats with their four limbs tied on a frame. It was found that microinjection of 5-HT (25 micrograms/10 microliters) into the 4th ventricle of the brain or bilateral microinjection of 5-HT (4 micrograms/0.5 microliters/site) into rostral ventrolateral medulla (rVLM) reduced stress-induced hyperviscosity (p < 0.01) and elevation of blood pressure (p < 0.01). The effect of 5-HT injected into the 4th ventricle or rVLM was blocked by bilateral microinjection of cinanserine (4 micrograms/0.5 microliter/site) into rVLM. These results suggest that microinjection of 5-HT into 4th ventricle and rVLM could reduce stress-induced hyperviscosity and elevation of blood pressure and these effects were probably mediated via 5-HT receptors in the rVLM.

Animals↗

PubMed1992

Extended parietal cell vagotomy in the treatment of perforation, hemorrhage and stenosis due to duodenal ulcer.

Ninety-five patients with perforation, hemorrhage or stenosis due to duodenal ulcer were treated by extended parietal cell vagotomy. Postoperative follow-up ranged from 3.5 to 10 years (mean 6 years) in 88 patients (92%) with acute perforation (60), hemorrhage (8) and stenosis (20). There was no operative mortality. Ulcer recurrence was 2.3%. Only one patient (5%) had restenosis and required reoperation. There was no recurrent hemorrhage and there were few long-term complications. According to the Visick classification, 67 patients (76%) belonged to grade I, 13 (14.7%) grade II, 4 (4.5%) grade III, and 4 (4.5%) grade IV. Extended parietal cell vagotomy proved to be safe with excellent results, low ulcer recurrence and few complications. Moreover, recurrent ulcers healed rapidly following medical therapy. The authors believe that extended parietal cell vagotomy should be the treatment of choice for acute perforation, hemorrhage or stenosis due to duodenal ulcer.

Adolescent↗

PubMed1987