ABSTRACT
This study was aimed to investigate the changes of hemodynamic parameters, pathology and c kit mRNA expression in myocardium after acute myocardial infarctionin (AMI) in rats, and to elucidate the relationship between these three kinds of changes. Sixty six adult male SD rats were randomly divided into normal group, Sham groups and ligation groups. The rat model of AMI was set up by ligating the left anterior descending artery. Hemodynamic parameters, pathological changes and c kit mRNA expression in myocardiam were examined. The results revealed that there were no statistically significant differences in hemodynamic parameters between normal group and Sham groups. Compared with the normal group, all ligation groups exhibited significantly decreased left ventricular systolic pressure (LVSP) and +/-dp/dtmax (P<0.01), and increased left ventricular end diastolic pressure (LVEDP, P<0.01). In the other ligation groups, compared with 6th hour group after ligation, there appeared striking increase of LVSP, LVEDP and +/-dp/dtmax (P<0.05). HE staining in myocardiam showed that there are necrosis and derangement at 24th hour group after ligation ,and a great number of inflammatory cells infiltration around the infarct zone at 3rd day group after ligation, and granulation tissue infiltrated into the infarct zone at 14th day group after ligation. In all five time points groups after ligation, the levels of c-kit mRNA expression were 0.99 fold, 1.06 fold, 1.46 fold, 1.91 fold and 2.67 fold, respectively, compared with Sham groups. The results suggest that cardiac stem cells in myocardium might contribute to the role of regenerating myocardium via self proliferation after acute myocardial infarction, but further investigation is still needed.
Subject(s)
Animals , Male , Rats , Hemodynamics , Physiology , Myocardial Infarction , Metabolism , Pathology , Myocardium , Metabolism , Pathology , Myocytes, Cardiac , Cell Biology , Proto-Oncogene Proteins c-kit , Genetics , Metabolism , RNA, Messenger , Genetics , Metabolism , Random Allocation , Rats, Sprague-Dawley , Stem Cells , Cell BiologyABSTRACT
This study was aimed at observing the effects of ovariectomy and estradiol on the microarchitecture of cancellous bone and exploring the influence of microarchitectural change on the biomechanical properties. Thirty 6-month-old unmated female SD rats were randomly divided into 3 groups (10 rat each): sham-operated control group (Sham), ovariectomized group (OVX)and Estradiol Benzoate treated group (EBT). All rats were housed in standard environmental conditions. Five months after operation, the rats were sacrificed. The biomechanical properties of the third lumbar vertebras (L3) were measured with compression testing in vitro. Micro-CT scanning was performed on the fourth lumbar vertebras (L4) in vitro. In comparison with the corresponding variables of Sham, the bone volume fraction (BV/TV) and the trabecular number (Tb. N) of OVX were reduced remarkably, and the trabecular separation (Tb. Sp) and the structural model index (SMI) of OVX were enhanced obviously. These facts implicated that the bone trabecular plate-like structure of OVX were decreased. BV/TV, Tb. N and the trabecular thickness (Tb. Th) of EBT were greater than those of OVX. Tb. Sp and SMI of EBT were much smaller than those of OVX. The results of mechanical test showed that the maximum forioe (Fmax), the maximum stress (sigmamax) and the elastic modeulus (E) of the lumbar vertebral cancellous bone of OVX were declined sharply, while the aforesaid biomechanical index of EBT was improved distinctly. The performance of three-dimensional micro-CT and the mechanical testing to assess microarchitecture of cancellous bone are useful for evaluating the state of osteoporosis and the antiosteoporotic effect of agents.
Subject(s)
Animals , Female , Rats , Biomechanical Phenomena , Estradiol , Pharmacology , Imaging, Three-Dimensional , Lumbar Vertebrae , Diagnostic Imaging , Pathology , Osteoporosis , Pathology , Ovariectomy , Random Allocation , Rats, Sprague-Dawley , Tomography, X-Ray ComputedABSTRACT
The effect of chitosan with different molecular weight and deacetylation degree on blood hemostasis was tested. The experiments found evident alteration of red blood cell morphology and unusual coagglutination between erythrocytes in the anticoagulant blood which was treated by chitosan acetic acid solution. The red blood cells clot formation experiments showed that chitosan with low deacetylation degree (60%-70%) caused more red blood cells to assemble when compared versus chitosan with other deacetylation degrees. The effect of molecular weight between 10(5)-10(6) was not obvious. The thrombin time (TT), prothrombin time (PT), activated partial thromboplastin time (APTT), and concentration of fibrinogen (FIB) of blood treated by chitosan acetic acid solution were measured. The results proved that the hemostasis property of chitosan acetic acid solution was independent of the platelets and the normal "Cascade-like" coagulation pathway.
Subject(s)
Animals , Rabbits , Acetic Acid , Chemistry , Pharmacology , Chitosan , Chemistry , Pharmacology , Fibrinogen , Hemostatics , Chemistry , Pharmacology , Partial Thromboplastin Time , Prothrombin Time , Thrombin TimeABSTRACT
Cardiopulmonary resuscitation board (CPR Board) is an essential tool in emergency care, which can keep the patient's airway open and support the patient in the administration of CPR. This paper introduces the structure, performances and clinical trials of a CPR board.
ABSTRACT
The effects of chitosan and N,O-carboxymethyl chitosan on blood hemostasis are tested.The dynamic blood coagulation experiments show chitsan with low deacetylation degree has higher absorption ability.The experiments can't find that any altered red blood cell morphology or an unusual affinity between erythrocytes appears evidently in the ACD blood treated with chitosan.The concentration of the platelets on the chitosan surface may be one of causes that platelets produce blood coagulation.Chitosan is substituted by the carboxymethyl and has water solubility.But N,O-carboxymethyl chitosan can lead torouleau and not toaltering the morphology of the erythrocyte.The blood hemostasis effect is not obvious.The values of TT,PT,APTT and FIB are measured from blood and the results fail toprove that chitosan and N,O-carboxymethyl chitosan can activate the coagulation factors.
ABSTRACT
Chitosan have applied extensively in the field of medicine. We review the mechanism of chitosan hemostasis. The effect of chitosan on hemostasis is independent of all known“Cascade-like”coagulation pathways,induding platelets and soluble coagulant factors. Chitosan induce hemostasis by coalesce erythrocytes to one another to form a blood clot. In addition,the use of chitosan in hemostat is indicated in this paper.
ABSTRACT
Objective Study and determine the suitable negative pressure condition for a negative pressure isolator. Method The filter efficiency, pressure, capabilities of inner environment and physiological parameters of the user were tested in different negative pressure conditions. Results The different negative pressure conditions influence above mentioned capabilities of the isolator considerably except for the filter efficiency Conclusion Under the conditions of -30Pa～-50Pa,those are optimized the capabilities of inner environment and physiological parameters of the user.