基于两类媒介的炭疽传播模型的全局动力学分析

为了研究动物种群中媒介对炭疽传播的影响,该文依据尸食性蝇与血食性蝇的传播机制,建立了一个确定性传染病模型.利用微分方程基本定理证明了模型解的非负性和有界性,给出了平衡点存在的充分条件,定义了模型的几类再生数,利用线性化方法和M-矩阵等方法对平衡点的稳定性进行了分析,并研究了疾病的持久性.利用数值模拟研究了参数对基本再生数的影响.研究结果表明:及时清理染病尸体,尽量消除苍蝇的繁殖地点,对苍蝇使用杀虫剂对炭疽在动物种群中传播具有一定的抑制作用.

稀奇古怪的异食癖

吃石成癖的人 台湾宜兰县有个31岁的男子,竟然嗜石成癖,他一天不吃石头,便会烦躁不安。这个男子叫黄清松,是个低能力。据他的父母说,从3岁开始他就经常拾小石子吃,犹如一般小孩吃饼干,直到如今31岁,他已嗜石成癖;吃糖果或饼干,他会当场呕吐。平时吃饭他可吃可不吃,吃石头却很认真,一天不吃石头,便烦躁不安。据他母亲说,他每天入睡后。

Study on vasculogenic mimicry in malignant esophageal stromal tumors

AIM: To investigate whether malignant esophageal stromal tumors contain PAS-positive patterned matrix-associated vascular channels, which are lined by tumor cells, but not vascular endothelial cells. That is vasculogenic mimicry (VM) independent of tumor angiogenesis. METHODS: Thirty-six tissue samples of malignant esophageal stromal tumors were analyzed. Tissue sections were stained for Vascular endothelial growth factor (VEGF), CD31 and periodic acid Schiff (PAS). The level of VEGF, the microvascular density (MVD) and the vasculogenic mimicry density (VMD) were determined. RESULTS: PAS-positive patterned matrix-associated vascular channels were detected in 33.3% (12/36) of tumor samples. Within these patterned channels, red blood cells were found. The level of VEGF and the MVD in tumors containing patterned channels were significantly higher than those in tumors not containing patterned channels (P < 0.05). At the same time, the malignant degree of tumors was higher, the proportions of tumors containing patterned channels were not only more, but also in the each kind of tumors containing patterned channels. CONCLUSION: In malignant esophageal stromal tumors, a VM mechanism causes some tumor cells to deform themselves and secrete extracellular matrix; thus, PAS-positive patterned matrix-associated vascular channels appear and supplying blood to the tumors to sustain their growth and metastasis.

Prevalence of linked angina and gastroesophageal reflux disease in general practice

AIM： To evaluate the association between gastroesophageal reflux diseases （GERD） and coronary heart diseases. METHODS： One thousand nine hundred and seventy consecutive patients who attended our hospital were enrolled. All of the patients who first attend our hospital were asked to respond to the F-scale questionnaire regardless of their chief complaints. All patients had a careful history taken, and resting echocardiography （ECG） was performed by physicians if the diagnostic necessity arose. Patients with ECG signs of coronary artery ischemia were defined as ST- segment depression based on the Minnesota code. RESULTS： Among 712 patients （36%） with GERD, ECG was performed in 171 （24%）, and ischemic changes were detected in eight （5%）. Four （50%） of these patients with abnormal findings upon ECG had no chest symptoms such as chest pain, chest oppression, or palpitations. These patients （0.6%; 4/712） were thought to have non-GERD heartburn, which may be related to ischemic heart disease. Of 281 patients who underwent ECG and did not have GERD symptoms, 20 （7%） had abnormal findings upon ECG. In patients with GERD symptoms and ECG signs of coronary artery ischemia, the prevalence of linked angina was considered to be 0.4% （8/1970 patients）.CONCLUSION： The present study suggested that ischemic heart disease might be found although a patient was referred to the hospital with a complaint of GERD symptoms. Physicians have to be concerned about missing clinically important coronary artery disease while evaluating patients for GERD symptoms.

EFFECTS OF ACUTE HYPOGLYCEMIA ON THE OREXIN SYSTEM IN RAT

Objective To evaluate the effects of acute glucose level changes on expression of prepro-orexin, orexin 1 receptor (OX1R) and orexin 2 receptor (OX2R) mRNA in rat hypothalamus tissue and pancreatic islets cells. Methods Thirty adult male Wistar rats were randomly divided into three equal groups (n = 10). The acute hypoglycemia rat model was induced by a single subcutaneous injection of insulin. Twenty acute hypoglycemia rats were divided into group B and group C. Group B was allowed to eat freely, while group C was food-deprived. Control rats were injected the same volume of saline. The effect of glucose levels (2.8 mmol/L and 8.3 mmol/L) on pancreatic islet cell orexin system was detected in pancreas islet cell cultured in vitro. The expression of prepro-orexin and OXR mRNA was examined in rat hypothalamus tissue and pancreatic islets cell cultured in vitro using reverse transcription-polymerase chain reaction (RT-PCR). Results Expression of orexin mRNA increased about 150% for the food-deprived hypoglycemia rats in comparison with control group (P < 0.01), whereas expression of OX1R mRNA decreased up to 30% (P < 0.01). However, expression of OX2R mRNA was unchanged in comparison with control group. In vitro, after incubation with 2.8 mmol/L glucose for 6 hours, the expression of prepro-orexin mRNA increased 2 times in rat pancreas islet cells in comparison with 8.3 mmol/L glucose group (P < 0.01). But the expression of OX1R mRNA was not sensitive to acute glucose fluctuation.Conclusions Orexin in rat hypothalamus is stimulated by decline in blood glucose and inhibited by signals related to feeding. Moreover, glucose plays a role in modulating the gene expression of prepro-orexin in rat pancreatic islet cells.

Transmitted cardiovascular pulsations on high resolution esophageal impedance manometry, and their significance in dysphagia

AIM To investigate the behavior of pulsatile pressure zones(PPZ's) as noted on high resolution esophageal impedance manometry(HREIM), and determine their association with dysphagia.METHODS Retrospective, single center case control design scr-eening HREIM studies for cases(dysphagia) and controls(no dysphagia). Thoracic radiology studies were reviewed further in cases for(thoracic cardiovascular) thoracic cardiovascular(TCV) structures in esophageal proximity to compare with HREIM findings. Manometric data was collected for number, location, axial length, PPZ pressure and esophageal clearance function(impedance). RESULTS Among 317 screened patients, 56% cases and 64% controls had PPZ's. Fifty cases had an available thoracic radiology comparison. The distribution of PPZ's in these 50 cases and 59 controls was similar(average 1.4 PPZ/patient). Controls(mean 31.2 ± SD 12 years) were a significantly younger population than cases(mean 67.3 ± SD 14.9 years) with P < 0.0001. The upright posture PPZ pressure was higher in controls(15.7 ± 10.0 mm Hg) than cases(10.8 ± 9.7 mm Hg). Although statistically significant(P = 0.005), it was a weak predictor using logistic regression and ROC model(AUC = 0.65). Three dysphagia patients had partial compression from external TCV on radiology(1 aberrant subclavian artery, 2 dilated left atrium). The posture(supine vs upright) with more prominent PPZ's impaired bolus clearance in 9 additional cases by > 20%. CONCLUSION Transmitted TCV pulsations observed in HREIM bear no significant impact on swallowing. However, in older adults with dysphagia, evidence of impaired bolus clearance on impedance should be evaluated for external TCV compression. These associations have never been explored previously in literature, and are novel.

Phytogenic Feed Additive for Sows： Effects on Sow Feed Intake, Serum Metabolite Concentrations, IgG Level, Lysozyme Activity and Milk Quality

The objective of this study was to investigate the influence ofa phytogenic feed additive （PFA） to late-gestation （d 90） and lactation sows on their reproduction performance. Sixty Large White × Landrace primiparous sows were divided into four groups （fifteen sows per group）. The control group was fed with basal diet, the others were fed with basal diet supplemented with 0.02%, 0.04% and 0.06% PFA, respectively. Compared with the control, the sows in 0.04% PFA group had higher feed intake during lactation and higher litter weaning weight （P 〈 0.05）. At farrowing, glucose level in 0.04% PFA sows was higher than the control and sows in 0.02% PFA had the highest IgG content among the treatments （P 〈 0.05）. On day 7 of lactation, serum urea nitrogen contents were lower in response to PFA supplementation compared to the control （P 〈 0.05）. At the same time, sows fed the 0.06% PFA diet increased the lysozyme activity （P 〈 0.05）. The levels of milk lactose and IgG were increased in 0.02% and 0.04% PFA groups （P 〈 0.05）. In conclusion, feeding PFA improved sows and litter performance, serum metabolite concentrations, lgG level and lysozyme activity at postpartum and milk quality.

Application of transesophageal echocardiography to aortic embolic stroke

OBJECTIVES: To determine the relative value of transesophageal echocardiography (TEE) and transthoracic echocardiography (TTE) in exploring the potential embolic source (PES) in heart and aortic arch and to study the clinical significance of aortic arch atherosclerosis (AAA). METHODS: Forty-nine patients with cerebral embolism were included in this study. TEE and TTE were used to evaluate the potential source of emboli in aortic arch, heart and duplex in the carotid artery. An atherosclerotic lesion of the aortic arch was defined as normal, mild plaque, moderate plaque, and protruding plaque or mobile plaque. RESULTS: Of the 49 patients, 31 (63%) patients showed evidence of AAA: 7 (14.1%) patients were mild, 9 (18.4%) were moderate and 15 (30.6%) were severe. In those 15 patients, 11 had neither severe ICAA nor heart disease. Thirty-three patients had internal carotid arterial atherosclerosis (ICAA). The potential sources of embolization of heart and aortic arch is 48.98% by TEE, but only 18.4% by TTE; 9 patients had heart disease. Age and ICAA were significantly correlated with AAA. CONCLUSION: At present, TEE is a better method for exploring atherosclerotic lesions in the thoracic aorta. AAA is an important potential source of cerebral embolic stroke.

Effect of kidney-reinforcing,blood-activating and stasis-removing recipes on adhesion molecule expression of bone marrow mesenchymal stem cells from chronic aplastic anemia patients

OBJECTIVE： To explore the effect of kidney-rein- forcing, blood-activating and stasis-removing recipes on adhesion molecule expression of bone mar- row mesenchymal stem cells （MSCs） from patients with chronic aplastic anemia （CAA）. METHODS： We used three Traditional Chinese Medicine recipes, namely a kidney-reinforcing recipe （KRR）, blood-activating and stasis-removing recipe （BASRR）, and kidney-reinforcing, blood-activating and stasis-removing recipe （KRBASFIR）, and a nor- mal saline control to prepare herbal medicine se- rum in Sprague Dawley rats. Thirty CAA patients were enrolled in the experimental group, including 17 kidney-Yang deficient patients and 13 kidney-Yin deficient patients. Ten healthy individuals were included in the control group. MSCs were isolated from bone marrow samples, and the cell density was observed to measure their proliferation ability by microscopy on days 2, 7, and 14 after isolation. In addition, the expression of adhesion molecules of bone marrow MSCs （CD106, CD49d, CD31 and CD44） were detected by flow cytometry after 48 h of treatment with the four different herbal medi- cine serums. RESULTS： The proliferation of MSCs from kid- ney-Yang deficient and kidney-Yin deficient pa- tients was weaker than that of MSCs from the con- trol group. The expression of all adhesion mole- cules of bone marrow MSCs from CAA patients was obviously lower than that in the control group （P〈 0.01）. The expression of CD49d and CD31 in MSCs from patients with a kidney-Yin deficiency was low- er than in those with a kidney-yang deficiency （P〈 0.05 and P〈O.01, respectively）. For kidney-Yang defi- cient patients, CD31 expression in the KRBASRR group was significantly higher than that in the BASRR group （P〈O.01）, while CD44 in the KRBASRR group was significantly higher than that in both KRR and BASRR groups （P〈O.01）. For kidney-Yin defi- cient patients, CD106 and CD49d expression in the KRBASRR group was obviously higher than that in the KRR group （P〈0.05）, while CD31 and CD44 ex- pression in the KRBASRR group was significantly higher than that in both KRR and BASRR groups （P〈 0.05 and P〈0.01, respectively）. CONCLUSION： The bone marrow microenviron- ment in CAA patients is abnormal. The effect of KRBASRR may be better than that of KRR and BASRR for kidney-Yang deficient and kidney-Yin de- ficient patients by improving the expression levels of MSC adhesion molecules.

Application of transesophageal echocardiography to aortic embolic stroke

s To determine the relative value of transesophageal echocardiography (TEE) and tr ansthoracic echocardiography (TTE) in exploring the potential embolic source (PE S) in heart and aortic arch and to study the clinical significance of aortic arc h athersclerosis (AAA) Methods Forty nine patients with cerebral embolism were included in this study TEE an d TTE were used to evaluate the potential source of emboli in aortic arch, heart and duplex in the carotid artery An atherosclerotic lesion of the aortic arch was defined as normal, mild plaque, moderate plaque, and protruding plaque or m obile plaque Results Of the 49 patients, 31(63%) patients showed evidence of AAA: 7 (14 1%) patients were mild, 9 (18 4%) were moderate and 15 (30 6%) were severe In those 15 p atients, 11 had neither severe ICAA nor heart disease Thirty three patients h ad internal carotid arterial atherosclerosis (ICAA) The potential sources of e mbolization of heart and aortic arch is 48 98% by TEE, but only 18 4% by TTE; 9 patients had heart disease Age and ICAA were significantly correlated with A AA Conclusion At present, TEE is a better method for exploring atherosclerotic lesions in the thoracic aorta AAA is an important potential source of cerebral embolic stroke

Effect of Linguizhugan decoction on hyperlipidemia rats with intermittent fasting

OBJECTIVE:To explore the effect of Linguizhugan decoction on hyperlipidemia rats with caloric restriction.METHODS:The hyperlipidemia model of rat was induced by high fat diet for 8 weeks.After the model was established,26 rats were randomly divided into 4 groups:the control group(n=6),the model group(n=6),the intermittent fasting(IF) group(n= 8),and the IF and herbal medicine(IFH) group(n= 6).IF group was applied intermittent fasting every other day.The IFH group was given Linguizhugan decoction every day and intermittent fasting every other day.Blood samples were taken at the end of 16 weeks,and serum ghrelin and lipid was tested.RESULTS:Serum ghrelin in the IF group significantly increased(P<0.01).Serum ghrelin in IFH group was lower than the IF group(P<0.05),but higher than the model group(P<0.01).CONCLUSION:Linguizhugan decoction may play a part in regulation of energy and appetite in hyperlipidemia rats with IF.

Effect of Zhuyeshigao granule on tumor necrosis factor-α and inter leukins serum protein levels in rats with radiation esophagitis

OBJECTIVE： To investigate the effects of Zhuyesh- igao granule （ZSG） on tumor necrosis factor-a （TNF-a）, interleukin-1 （IL-1）, IL-2, IL-6, and IL-8 in rats with radiation esophagitis. METHODS： Fifty Wistar rats were randomly divid- ed into five groups （10 rats in each group）： con- trol （without radiation）, saline-treated, and low, medium, and high-dose ISG-treated groups. Rats were given normal saline （10 mL/kg） or 1.15, 2.3, or 4.6 g/kg ZSG by intragastric administration once a day for 7 days. A rat model of radiation esophagi- tis was established by local irradiation of Co60 （490.25 cGy/min, totaling 30 Gy）. The administra- tion of ZSG was continued for another 7 days and on the 7th day post-irradiation, inferior vena cavablood was collected. The serum was separated, and TNF-a, IL-1, IL-2, 11_-6, and IL-8 protein levels were determined. RESULTS： Inflammatory response factors were found in the serum of each group. However, levels in ZSG-treated groups were significantly lower than in the saline-treated group （P〈0.05）. CONCLUSION： ZSG may prevent the development of radiation esophagitis, perhaps by inhibiting the generation and release of the inflammatory re- sponse factors TNF-a, IL-1, IL-2, IL-6, and IL-8.

Modified Dachengqi Tang improves decreased gastrointestinal motility in postoperative esophageal cancer patients

OBJECTIVE:To investigate the clinical effects of modified Dachengqi Tang(DCQT) on promoting gastrointestinal motility in post-operative esophageal cancer patients.METHODS:Sixty postoperative esophageal cancer patients were enrolled and randomly assigned to the modified treatment group or the control group(30 patients in each group).Patients in the treatment group were given DCQT made from decocted herbs and administered via nasojejunal tube at a dosage of 150 mL.Gastrointestinal motility was assessed by recording time for recovery of bowel sounds,flatus,defecation,and the total amount of gastric drainage during the first three postoperative days.Plasma motilin(MTL) and vasoactive intestinal peptide(VIP) were measured one hour before and three days after surgery.RESULTS:Compared with the control group,the times to first bowel sound,flatus,and defecation were significantly shorter and there was less gastric drainage in the treatment group(P < 0.01,P < 0.01,P < 0.01,and P < 0.05,respectively).In the treatment group,postoperative plasma MTL was significantly higher(P < 0.01) and VIP was significantly lower than those in the control group(P < 0.05).There was no difference found in either MTL or VIP from before to after operation in the treatment group(P > 0.05).MTL was significantly lower and VIP was higher postoperatively in the control group,compared to before surgery(P < 0.01).CONCLUSION:Modified DCQT effectively improved decreased gastrointestinal motility in postoperative esophageal cancer patients by increasing MTL and reducing VIP.