Conventional medical experiments can hardly simulate cardiac excitation propagation and observe the evolvement of cardiac electrical activities firsthand as is possible with computer simulation. Based on the anatomic structure of the heart, simulation of cardiac electrical activity mainly consists of the emulation of the excitation process among the cardiac cells and calculation of the electrical activities of individual cardiac cells. In this study we establish a geometric ventricular structure model demonstrating the direction of the cardiac muscle fibers and the layers of the ventricular cells, and endow different action potential models to the ventricular cells of different layers, and observe the activation process of the ventricular parts in view of the three-dimensional anatomy. This method gives attention to both enough calculation amounts and efficiency, which achieves satisfactory simulation results of ventricular electrical activity based on the anatomic structure and cell electrophysiology through an improved algorithm on personal computer.
Algorithms ; Computer Simulation ; Electrophysiology ; Heart ; anatomy & histology ; physiology ; Humans ; Models, Anatomic ; Models, Cardiovascular

OBJECTIVETo study the role of O(6)-methylguanine-DNA methyltransferase (hMGMT) in the development of human lung cancer.

METHODSReverse transcription-polymerase chain reaction (RT-PCR) method was applied to measure hMGMT mRNA expression in 150 lung cancer specimens, 40 normal lung tissues, and in the peripheral mononuclear blood cells from 50 lung cancer cases and 50 normal controls. The protein expressions of p53, C-MYC and K-RAS were assessed by immuno-histochemistry. The effects of some exposure factors on the expression of hMGMT gene were analyzed. The relationships between hMGMT gene and cancer related genes p53, C-MYC and K-RAS were investigated.

RESULTSThe mRNA of hMGMT was low or absent in 49 of 150 (32.7%) lung cancer specimens, whereas 2 of 40 (5%) normal lung tissues had reduced the levels of hMGMT mRNA. The low expression of hMGMT seemed to be a risk factor of lung cancer, with a OR of 9.22 (2.05-57.65). Reduced expression levels of hMGMT mRNA were observed in 10 of 50 (20%) lung cancer patients' peripheral mononuclear blood cells, and 2 of 50 (4%) blood cells among normal controls. When investigating the exposure factors which affecting the expression of hMGMT gene, we noticed that smoking was suppressing the expression of hMGMT gene. Interestingly, over-expression of K-RAS oncogene was significantly correlated with low expression of hMGMT (P < 0.05). However, the expressions of p53 and C-myc were not correlated with the status of hMGMT gene.

CONCLUSIONhMGMT might play an important role in the development of human lung cancer. Low expression of hMGMT gene seemed to be a risk factor for lung cancer which could be used as a valuable biomarker on susceptibility of human lung cancers.

Adult ; Aged ; Biomarkers, Tumor ; Carcinoma, Squamous Cell ; enzymology ; genetics ; China ; epidemiology ; DNA Repair ; genetics ; Female ; Genes, ras ; genetics ; Humans ; Lung Neoplasms ; enzymology ; genetics ; Male ; Middle Aged ; O(6)-Methylguanine-DNA Methyltransferase ; biosynthesis ; genetics ; metabolism ; Point Mutation ; RNA, Messenger ; biosynthesis ; genetics ; Smoking ; adverse effects ; ras Proteins ; biosynthesis ; genetics

OBJECTIVETo analyze the relationship between the normalized difference vegetation index (NDVI) and the snail distribution in marshland of Jiangning county in Jiangsu province, and to explore the utility of Terra-MODIS image map in the small scale snail habitats surveillance.

METHODSNDVI were extracted from MODIS image by vector chart of the snail distribution using ArcView 8.1 and ERDAS 8.5 software. The relationship between NDVI and the snail distribution were Investigated using Bivariate correlations and stepwise linear regression.

RESULTSThe snail density on marshland was positively correlated with the mean NDVI in the first ten-day of May and the maximum NDVI (N(20max)) in the last ten-day of May. Incidence of pixel with the live snail on marshland was positively correlated with the mean NDVI (N(2mean)) in the first ten-day of May. An equation Y(1) = 0.009 47 x N(20max) (R(2) = 0.73), Y(2) = 0.018 6 x N(2mean) (R(2) = 0.906) was established.

CONCLUSIONThis study showed that the Terra-MODIS satellite images reflecting the status of the vegetation on marshland in Jiangning county could be applied to the study to supervise the snail habitat. The results suggested that MODIS images could be used to survey the small scale snail habitats on marshland.

Animals ; Breeding ; China ; epidemiology ; Ecology ; Environmental Monitoring ; Epidemiological Monitoring ; Humans ; Satellite Communications ; Schistosomiasis japonica ; epidemiology ; transmission ; Seasons ; Snails ; growth & development ; parasitology ; physiology

OBJECTIVETo study the effect of Hongjingtian (Gadol) injection on cardiac hemodynamics and myocardial oxygen consumption for analyzing its underlying mechanism in the treatment of coronary heart disease.

METHODA total of 20 dogs anesthetized with pentobarbital sodium (30 mg x kg(-1), i.v.) were evenly randomized into control group, low-dose Gadol (LDG) group, high-dose Gadol (HDG) group and Herbesser Injection group. The blood flow volume (BFV) of the left coronary artery and cardiac output (CO), left ventricular pressure (LVP), maximum ascending rate (dp/dtmax) of LVP, mean arterial pressure (MAP) of the femoral artery, oxygen contents of the coronary artery and coronary vein (venous sinus), oxygen consumption index (OCI), cardiac index (CI), coronary artery resistance (CAR) and total peripheral resistance (TPR) as well as oxygen utilization rate (OUR) were detected respectively.

RESULTAfter venous injection of Gadol, CAR, MAP, TPR, OCI, myocardial oxygen consumption and heart rate lowered significantly (P < 0.05-0.01), while BFV and blood oxygen content of the venous sinus increased considerably (P < 0.05-0.01) in comparison with pre-injection. No significant differences were found in LVP and myocardial contractivity between control group and LDG, and between control and HDG groups respectively.

CONCLUSIONIt showed dilation of the coronary artery and reduction of the cardiac afterload after injection of Gadol. Besides, CO and stroke volume increased considerably and the cardiac effective work was raised without any significant simultaneous increase of both myocardial contractility and LVP. A decrease in the myocardial oxygen consumption and reduction of OCI indicates an improvement of the oxygen supply of the myocardium, and a favorable regulation of the compliance of the cardiac vessels. As a result, the cardiovascular performance was ameliorated. The abovementioned improvement of these indexes may contribute to the therapeutic effect of Gadol in the treatment of coronary heart disease in clinic.

Animals ; Blood Pressure ; drug effects ; Cardiac Output ; drug effects ; Dogs ; Drugs, Chinese Herbal ; isolation & purification ; pharmacology ; Female ; Heart Rate ; drug effects ; Hemodynamics ; drug effects ; Injections, Intravenous ; Male ; Myocardium ; metabolism ; Oxygen ; metabolism ; Plants, Medicinal ; chemistry ; Random Allocation ; Rhodiola ; chemistry ; Vascular Resistance ; drug effects

Objective: To investigate the characteristics and comprehensive treatment of infected wounds in patients with iatrogenic Cushing's syndrome. Methods: A retrospective observational study was conducted. From May 2012 to December 2021, the data of 19 patients with iatrogenic Cushing's syndrome discharged from the Department of Burns and Plastic Surgery of the First Affiliated Hospital of Guangxi Medical University were collected, including 8 males and 11 females, aged 28-71 (56±11) years, with 12 cases of infected acute wounds and 7 cases of infected chronic wounds. The lesions were located in the limbs, perianal, and sacrococcygeal regions, with original infection ranging from 9 cm×5 cm to 85 cm×45 cm. After admission, the patients were performed with multidisciplinary assisted diagnosis and treatment, and the wounds were treated with debridement and vacuum sealing drainage, according to the size, severity of infection, suture tension, and bone and tendon tissue exposure of wounds, direct suture or autologous skin and/or artificial dermis and/or autologous tissue flap transplantation was selected for wound repair. The levels of cortisol and adrenocorticotropic hormone (ACTH) of patients at 8:00, 16:00, and 24:00 within 24 h after admission were counted. After admission, the number of operations, wound repair methods, and wound and skin/flap donor site healing of patients were recorded. During follow-up, the wounds were observed for recurrent infection. Results: The cortisol levels of 16 patients at 8:00, 16:00, and 24:00 within 24 h after admission were (130±54), (80±16), and (109±39) nmol/L, respectively, and ACTH levels were (7.2±2.8), (4.1±1.8), and (6.0±3.0) pg/mL, respectively; and the other 3 patients had no such statistical results. After admission, the number of surgical operation for patients was 3.4±0.9. The following methods were used for wound repair, including direct suturing in 4 cases and autologous skin and/or artificial dermis grafting in 9 cases, of which 2 cases underwent stage Ⅱ autologous skin grafting after artificial dermis grafting in stage Ⅰ, and 6 cases had pedicled retrograde island flap+autologous skin grafting. The wound healing was observed, showing that all directly sutured wounds healed well; the wounds in 6 cases of autologous skin and/or artificial dermis grafting healed well, and the wounds in 3 cases also healed well after the secondary skin grafting; the flaps in 4 cases survived well with the wounds in 2 cases with distal perforators flap arteries circumfluence obstacle of posterior leg healed after stage Ⅱ debridement and autologous skin grafting. The healing status of skin/flap donor sites was followed showing that the donor sites of medium-thickness skin grafts in the thigh of 4 cases were well healed after transplanted with autologous split-thickness grafts from scalp; the donor sites of medium-thickness skin grafts in 3 cases did not undergo split-thickness skin grafting, of which 2 cases had poor healing but healed well after secondary skin grafting 2 weeks after surgery; the donor sites of split-thickness skin grafts in the head of 2 patients healed well; and all donor sites of flaps healed well after autologous skin grafting. During follow-up of more than half a year, 3 gout patients were hospitalized again for surgical treatment due to gout stone rupture, 4 patients were hospitalized again for surgical treatment due to infection, and no recurrent infection was found in the rest of patients. Conclusions: The infected wounds in patients with iatrogenic Cushing's syndrome have poor ability to regenerate and are prone to repeated infection. Local wound treatment together with multidisciplinary comprehensive treatment should be performed to control infection and close wounds in a timely manner, so as to maximize the benefits of patients.
Adrenocorticotropic Hormone ; China ; Cushing Syndrome/surgery* ; Female ; Gout ; Humans ; Hydrocortisone ; Iatrogenic Disease ; Male ; Skin, Artificial ; Wound Infection