Effect of successive irrigation of subarachnoid cavity on body temperature and cerebrospinal fluid-related index in suppurative meningitis model dogs

BACKGROUND: At present, suppurative meningitis is mainly treated through anti-infection with antibiotics, depressing encephalic pressure with mannitol , lowering body temperature with drugs , supporting treatment, etc. However, it takes a long course of treatment and has poor therapeutic effect. Successive irrigation of subarachnoid cavity maybe have better effect on suppurative meningitis. OBJECTIVE: We compared the successive irrigation of subbarachnoid cavity with routine therapeutic methods to observe the effect of successive irrigation of subarachnoid cavity on the body temperature, cerebrospinal fluid pressure, the number of white blood cell and the level of protein of suppurative meningitis dogs. DESIGN: A randomized and controlled animal experiment. SETTING: Institute of Neuroscience, Taihe Hospital Affiliated to Yunyang Medical College. MATERIALS: Totally 17 healthy adult male Beagle dogs, of common grade, weighing 9 to 10 kg, were involved in the experiment, and raised in the 20 ℃ temperature with relative humidity of 50% for 1 week. They were randomized into 3 groups: normal group (n=5), control group (n=5) and irrigation group (n=6). Artificial cerebrospinal fluid was prepared according to the level of glucose and chloride of cerebrospinal fluid of normal dogs, and then it was sterilized with high pressure. METHODS: This experiment was carried out in the experimental animal center of Yunyang Medical College from April to August 2001. ① After the dogs were anesthetized,1 mL fresh staphylococcus aureus liquid [(1.5-1.6)×109 L-1] was injected into medullary cistern to establish suppurative meningitis models. ② After models were successfully established, intravenous drip infusion of 1.2 ×106 U/(kg·d), muscular injection of sulfadiazine sodium of 100 mg/(kg·d)and intravenous injection of 200 g/L mannitol of 5 g/(kg·time) for 3 times a day were performed in the control group. The irrigation of subarachnoid meningitis was conducted in the irrigation group besides the routine treatments in the control group: Artificial cerebrospinal fluid was successively injected into the epidural catheter in the waist part. The mixtures of artificial cerebrospinal fluid and inflammatory cerebrospinal fluid flowed out incessantly from epidural catheter of medullary cistern. Irrigation was ended 48 hours later. Dogs were routinely raised in the control group. ③ From the first day after being modeled to the 14th day after treatment, the rectal temperatures were daily measured in the morning, at noon and in the evening respectively, then the mean temperatures were calculated . From the 2nd day after being modeled to the 14th day after treatment, puncture at waist was given once, and the cerebrospinal fluid pressure, the number of white blood cells and the level of protein were measured. MAIN OUTCOME MEASURES: The body temperature, cerebrospinal fluid pressure, the number of white blood cells and the level of protein were measured on suppurative meningitis model dogs. RESULTS: Totally 17 Beagle dogs were involved in this study. ①The body temperatures of dogs were significantly reduced in the control group and in irrigation group on the 1st day after treatment and lower than suppurative meningitis model dogs on the 2nd day after being modeled (P < 0.05). The body temperatures were gradually decreased in control group from the 2nd day after being modeled to the 14th day after treatment (P < 0.01), but were significantly higher than those of dogs in normal group on the 14th day after treatment (P < 0.05). The body temperatures of dogs were gradually decreased in irrigation group on the 2nd day or 3rd day after treatment (P < 0.01) and then were close to the normal body temperature on the 14th day after treatment. ②There was the same cerebrospinal fluid pressure in control group as in irrigation group on the 2nd day after being modeled (P > 0.05), but significantly decreased in two groups from the 1st day or 2nd day after treatment (P < 0.01), and cerebrospinal fluid pressure was close to the normal level in irrigation group. Although the cerebrospinal fluid pressure raised a little on the 3rd day or 4th day after treatment in the irrigation group (P < 0.05), but recovered to the normal level on the 9th day after treatment again. It decreased slowly in the control group and still was significantly higher than normal group on the 14th day after treatment (P < 0.01). ③No significant difference existed in number of white blood cell and the level of protein between control group and irrigation group on the 2nd day following modeled. Both of them began to significantly decrease on the 1st and 2nd day after treatment (P < 0.01). Although the number of white blood cell and the level of protein rebounded a little in irrigation group 3 or 4 days after treatment (P < 0.05), they were gradually decreased and recovered to normal levels on the 13th day after treatment. The number of white blood cell and the level of protein slowly decreased in the control group compared with irrigation group and were still significantly higher than normal group on the 14th day (P < 0.01). CONCLUSION: Irrigation of subarachnoid cavity can decrease the body temperature, cerebrospinal fluid pressure, the number of white blood cells and the level of protein at early stage of suppurative meningitis , and the therapeutic effect is better than that of routine treatment.

An experimental study on preventive effect of continuous irrigation from peridural adhesion after laminectomy

Objective To observe the preventive effect of continuous irrigation with sodium hyaluronate injection from peridural adhesionaminectomy.Methods Larninectomies were performed in L1,L4,L7 of 25 New Zealand rabbits respectively with 3

Influence of the heat irrigating effect of radiofrequency ablation on regional liver tissue in Bama miniature pigs

BACKGROUND The results of the heat irrigating effect of radiofrequency ablation(RFA)are uncertain,and the accurate impact of the heat irrigating effect on regional liver tissue is unknown due to a lack of control experiments.AIM The aim of this study was to determine the influence of the heat irrigating effect of RFA on regional liver tissue in Bama miniature pigs.METHODS Eight Bama miniature pigs were randomly divided into the observation group(group A)and the control group(group B),with 4 pigs/group.An RFA electrode needle was implanted near the hepatic segment vasculature(3-5 mm from the hepatic segment portal vein)under ultrasound guidance in group A.Similarly,an RFA electrode needle was implanted far from the hepatic segment vasculature(8-10 mm from the hepatic segment portal vein)in group B.The left internal lobe and right medial lobe were chosen as RFA sites in each pig.RFA was performed at the left internal lobe on day one in each pig,and at the right medial lobe 7 d later.Each RFA lasted 12 min.The general status of the pigs and serious complications were observed during the perioperative period.The pigs were sacrificed and the livers were removed immediately after RFA on the eighth day.The samples were roughly observed.Hematoxylin-eosin and Ki67 staining,as well as TUNEL detection,were performed on the tissue sections.RESULTS All 8 animals successfully underwent ultrasound-guided RFA.No serious complications,such as massive hemorrhage,biliary fistula,severe pleural effusion,pneumothorax,peripheral organ failure,or renal failure occurred in any of the animals during the perioperative period.The RFA coagulative necrosis lesion was spherical and the surrounding liver tissue showed an inflammatory response.The difference in the Suzuki score of the liver tissue surrounding the ablated portal vein,and its distal area between groups A and B,was statistically significant(P<0.05).More apoptotic cells were seen in liver tissue surrounding the ablated portal vein and its distal area in group A,while fewer apoptotic cells in the same area were seen in group B.The difference in the apoptotic index of the above area between group A and group B was statistically significant(P<0.05).Cells staining positive for Ki67 were observed in liver tissue at the left internal lobe around the ablated portal vein and its distal area in group A.No Ki67 staining positive cells were observed in other tissue sections.The difference in the Ki67 staining positive index in the above area was statistically significant(P<0.05)between group A and group B.CONCLUSION Changes as a result of thermal damage occur in liver tissue around the ablated portal vein and its distal area due to the heat irrigating effect when the RFA electrode tip is close to(<5 mm)the portal vein.

Determination of the effective utilization coefficient of irrigation water based on geographically weighted regression

This study uses geographically weighted regression to determine the spatial distribution of the effective utilization coefficient of irrigation water in Zhejiang Province,China,owing to the influences of spatial attributes on the irrigation efficiency.The sample set of this study comprised 165 agricultural test sites.A multivariate linear regression model and a geographically weighted regression model were established using the effective utilization coefficient of agricultural irrigation water as the dependent variable in addition to a suite of independent variables,including the actual irrigation area,the percentage of farmland using water-saving irrigation,the type of irrigation area,the net water consumption per mu,the water intake method,the terrain slope,and the soil field capacity.Results revealed a positive spatial correlation and noticeable agglomeration features in the effective utilization coefficient of irrigation water in Zhejiang Province.The geographically weighted regression model performed better in terms of fit and prediction accuracy than the multivariate linear regression model.The obtained findings confirm the suitability of the geographically weighted regression model for determining the spatial distribution of the effective utilization coefficient of irrigation water in Zhejiang,and offer a new approach on a regional scale.

Climatic impacts induced by winter wheat irrigation over North China simulated by the nonhydrostatic RegCM4.7

Quantification of the impact of winter wheat irrigation on the climate and the occurrence of extreme climatic events over North China is crucial for regional adaptation planning.Previous related studies mainly focused on the impact on surface processes;however,few focused on the effects of extreme events using high-resolution nonhydrostatic regional climate models.Here,the 9-km-resolution nonhydrostatic RegCM4.7 was coupled with a crop irrigation scheme and an updated winter wheat irrigation dataset to better simulate irrigation effects.Two experiments were conducted with and without winter wheat irrigation to isolate the effects of irrigation.Results showed that irrigation simulation reduces the model biases in temperature,precipitation,latent heat flux,soil moisture,sensitive heat flux,and top-layer soil moisture.Moreover,it also reduces the bias and increases the correlation with observations obtained in irrigated areas,especially in summer,indicating better representation of irrigation schemes.Winter wheat irrigation tends to cause substantial cooling of the local surface maximum,minimum,and mean air temperatures(by-1.68,-0.34,and-0.79℃,respectively)over irrigated areas of North China,with the largest changes observed in relation to maximum temperature.Additionally,precipitation is found to increase during spring and summer,which is strongly related to water vapor transport in the lower levels of the atmosphere.Further analyses indicated that the number of annual mean hot days decrease(-13.9 d),whereas the number of both comfort days(+10.2 d)and rainy days(days with total precipitation greater than 1 mm:+6.6 d)increase over irrigated areas,demonstrating beneficial feedback to human perception and agriculture.Fortunately,although the heat wave risk increases(number of annual mean heat wave days:+5.8 d),the impact is limited to small areas within irrigated region.Additionally,no notable change was found in terms of heavy rainfall events and precipitation intensity,which might be an undereastimation caused by the less water use in model simulation.Although winter wheat irrigation does not have notable impact on the climate of the surrounding region,it is an important factor for the local-scale climate.