Using whole-cell patch-clamp technique, the effect of radiofrequency catheter ablation (RFCA) on calcium current (Ic_a) of guinea pig ventricular myocytes was examined. The radiofrequency energy delivered was 20 W× 10 s. RFCA decreased Ic_a apparently with the affected area reaching up to 1.2 cm from the ablation focus. In the meanwhile, the pathological lesion size resulted from RFCA was merely 0. 41 ±0. 11 cm. These findings indicate that RFCA, apart from causing tissue necrosis by heat, can affect myocyte membrane currents in a large area. This may explain why RFCA has a very high success rate with a small pathological lesion.

To develop an easy, reproducible experimental model of cerebral infarction (CD without craniotomy in New Zealand white rabbits, a silicone rubber cylinder embedded in a nylon suture was delivered to the middle cerebral arteries through the internal carotid artery in anesthetized animals. Rabbits were sacrificed 0. 5 –5 h after embolization. CI size and location were ascertained by the triphenyl–2H-tetrazolium chloride (TTC) staining method; cerebral blood flow (CBF) was measured prior to and after embolization. in all rabbits after 4 h of ischemia, in 50 % after 3 h and only in 33 % after 2. 5 h. CI did not occur within less than 2. 5 h of ischemia. No correlation was found between size and location of CI and occlusion time. CBF was maximally reduced in the fight MCA territory but was also reduced in both anterior cerebral arteries and left MCA territories. This model is technically easy and the retrievable embolus allows the study of reperfusion by pulling on the nylon suture. It is suitable for studying chemical and molecular changes of the ischemic cells and/or for studying neuroimage changes after ischemic stroke.

Using biplane transesophageal echocardiography and the concept of three dimensional transthoracic echocardiography, we performed three dimensional reconstruction of transesophageal images of various clinicopathologic cases, including atrial septal defect, mitral stenosis, mitral valve prolapse and pulmonary stenosis. The hardware equipments and image processing flow chart of three dimensional reconstruction of transesophageal echocardiographic images are described. Our present study indicates that three dimensional reconstruction of transesophageal echocardiographic images could display multi-regional three dimensional structures of heart and great vessels, including superior vena cava, ascending aorta, right ventricular outflow tract, pulmonary artery and left heart, with clear, visual and stereoscopic imaging. The regional structures could be displayed at different levels of stereo-anatomic-secr tions and in different orientations of rotating stereo-images, which could provide accurate three dimensional anatomical information for cardiac stereo-morphological study and definition of spatial location and size of cardiac abnormalities.

Whether or not the pericytes exist in the intra-acinar pulmonary arteries and their normal structure and morphological changes during development of the structural remodeling of pulmonary vessels were observed using a pulmonary hypertension model in rats induced by monocrotaline injection. The results showed that the pericytes in the peripheral pulmonary vessels proliferated and transformed into smooth muscle cells during development of pulmonary hypertension, and at the same time, the pericytes could synthesize and secrete extracellular matrix including collagen, suggesting that the pericytes play an important role in the development of pulmonary hypertension and structural remodeling of the pulmonary vessels.

The effects of 3,4-DHAP on hypoxic pulmonary and systemic vascular responses were studied in anaesthetized dogs. The percentage change in pulmonary vascular resistance (Δ PVR %) and that in systemic vascular resistance (Δ SVR %) induced by 5 min hypoxia decreased significantly. 3,4-DHAP in doses of 1 mg/kg, 3 mg/kg, and 10 mg/kg i. v caused a decrease in Δ PVR% from the control value of 47.27±22.27 % to 24.62±21.76 %, 18–15±18.73 %, and 24.10 ±19. 76 % respectively, and a decrease in Δ SVR % from the control value of 12. 91 ±7. 39 % to-0. 34±12. 70 %, −2.11 ±12. 76 %, and -2.37±15. 52 % respectively. The results showed that 3,4-DHAP could decrease the hypoxic responses of pulmonary and systemic blood vessels. But it did not change Δ PVR % or Δ SVR % in dose of 30 mg/kg, neither did it influence the heart rate, cardiac output or cerebral blood flow during hypoxia in all the doses used.

The model of membranous glomerulonephritis (MGN) in rats was successfully established using self-made cationic bovine serum albumin (C-BSA) and treated with Huangdan Decoction (HDD) andTripterygium Wilfordii Co. tablet (TW). Results indicated that the levels of urinary protein, blood urea nitrogen (BUN) and serum creatinine (Scr) in treated groups (groups A, B and C) were significantly decreased as compared with the control group (group D) (P<0. 01). By light and electron microscope and immunofluorescent technique, the damage to kidney in groups A, B and C was found much milder than that in group D with lesion in group A being slightest. These findings suggest that HDD and TW may alleviate the pathological lesions of MGN, prevent or retard its progression, and have remarkable therapeutic effects on MGN.

The effect of Huoxuequyu recipe on erythrocyte membrane Ca²⁺-ATPase activity in pregnant rats with passive smoking induced asymmetrical intrauterine growth retardation (IUGR) was observed. The rats were divided into three groups: control group, model group and treated group. The fetal mean birth weight and erythrocyte membrane Ca²⁺-ATPase activity were found to be decreased in the model group as compared with the control and treated groups. There was a significant difference between the model group and the control group (P<0.01), while no significant difference existed between the treated group and the control group (P>0. 05). Furthermore, the findings indicated that the erythrocyte membrane Ca²⁺-ATPase activity seem to be positively correlated with the birth weight (P<0. 05).

On the basis of our observation, it is believedthat the Huoxuequyu decoction could increase erythrocyte membrane Ca²⁺-ATPase activity and promote blood circulation, thereby exerting a beneficial effect on fetal development.

The morphology of corneal innervation was studied in rabbits with alloxan-induced diabetes. The experimental rabbits were killed after 6, 8, 10, 12 weeks. Corneal innervation was studied by histochemical techniques and transimission electron microscopy. The results revealed that in diabetic rabbits, from 6 weeks, the density of nerve-nets was markedly sparser, the fibers were thinner and the activity of nerves was lower than those of the control group. Ultrastructural changes showed swelling of axons, irregular distribution of fibril and degeneration of mitochondria of varying degree. With the progress of disease the above changes were becoming more marked gradually. It may be assumed that these changes are related to hyperglycemia.

In this study, microcomputer image processing and pattern recognitiontechnology, and the knowledge of morphology and optical characteristics ofCryptococcus neoformans were used for identification ofCryptococcus neoformans. Four groups of mice were lethally infected with standard strain, Wuhan strain, American B-2643 strain and Var. Shanghainesis of theCryptococcus neoformans. The samples collected included mice brain, lung, kidney, liver, small intestine tissue and were observed under a light microscope. More than 600 images of the fungus were input into a microcomputer. A system of computer for automatic identification of theCryptococcus neoformans was developed. The technique involved image preprocessing, image segmenting, coding of line-length on the edge, curve fitting, extracting of image feature, building of image library and feature data bank etc. And then, 768 images of the clinical samples and other fungus samples whose morphological features tend to be confused withCryptococcus neoformans were input into microcomputer and subjected to automatic identification. TheCryptococcus neoformans was accurately identified within 15 min, and the consistence rate with results of routine culture was 98 %.

Bletilla striata and gelfoam were used as embolizing agents for the embolization of various hepatotropic vessels in dogs. The results proved thatBletilla striata was superior to gelfoam. The mechanisms of embolization byBletilla striata are attributable to following factors; non—absobent property, machanical obstruction; effects on coagulative and auticoagulative systems and secondary obstruction resulted from the injury to wall of blood vessels.

This study aimed at the exploration of the relationship between Na⁺H⁺ exchange system and myocardial ischemia-reperfusion injury (MRI) in an attempt to provide a theoretic basis for the prevention and treatment of MRI. We used the isolated working guinea pig hearts as the experimental model to mimick cardiopulmonary bypass, which included 120 min hypothermic ischemic cardioplegic arrest followed by 60 min normothermic reperfusion. The hearts were divided into 2 groups: the control group receiving St. Thomas’ Hospital Solution (STS) and the treated group receiving STS + amiloride, a Na⁺-H⁺ exchange blocker. The results showed that during reperfusion. [Na⁺]i and [Ca²⁺_i overloads, poor recovery of cardiac function, increases in CPK release and OFR generation, reduction of ATP content and serious damage of ultrastructure were seen in group 1; whereas there were no [Na⁺]_i and [Ca²⁺]_i overloads and better recovery of cardiac function accompanied by improved results of biochemical assay and less damage of ultrastructure was found in group 2. Our study indicates that amiloride can inhibit Na⁺™H⁺ exchange system in cardiac cells during early reperfusion period, which prevents [Na⁺]_i overload produced by Na⁺™H⁺ exchange, and stops Na⁺™Ca²⁺ exchange activated by high level of [Na⁺]_i, thus attenuating [Ca²⁺]_i overload caused by Na⁺™Ca²⁺ exchange and myocardial injury. Therefore, we conclude that Na⁺™H⁺ exchange blocker, amiloride, can exert significant protective effects on MRI and its use may prove to be a new clinical approach to prevention and cure of MRI.

A suspension of iodized oil and anticancer agent was injected into the portal veins of 20 rats with hepatic carcinoma. Oil drops were seen in tumor cell lines, small blood vessels inside the cancer nest, the sinusoid, and the central veins. After injection of oil suspension through the portal vein the distal small vessels were embolized and necrotic changes of tumor cells and their subordinate normal liver cells were observed. The results obtained in this experiment provided a good anatomical and pathological basis for treating liver cancers with the portal vein embolization with chemotherapeutic agents.

965 workers engaged in working tasks of work intensity grade 2,3,4 (based on Chinese National Standard) were investigated on the musculoskeletal disorders with a questionnaire. The lumbar vertebra of 136 randomly chosen workers were also radiologically examined. The result revealed that the prevalence of low—back disorders was 51–2 % on average and it was obviously correlated with such factors as age, standing, previous back injury, education level, sport activity, work intensity, working posture, satisfaction with the tools as well as work condition and house work. Heavy work load and unneutral working posture were proved to be the main factors as revealed by the multifactor analysis and further supported by the findings of X-ray examination.