用微量细胞培养ELISA测定HCLV TCID_(50)

应用猪瘟兔化弱毒制备的猪瘟兔化疫苗常因为剂量不足而引起免疫失败。究其原因主要是因为兔检(RID)合格的猪瘟兔化苗批间差异较大,质量不稳定。为此建立微量细胞培养ELISA用以测定HCLV TCID50,并获得成功,可以替代RID测毒。

MR diffusion-weighed imaging of rabbit liver

AIM： To study the techniques of MR diffusion-weighed imaging （DWI） for normal rabbit liver. METHODS： After 15 normal New Zealand white rabbits and one New Zealand white rabbit implanted with VX-2 tumor were anesthetized with 30 soluble pentobarbitone, DWI was performed respectively for different b values, repetition times （TR） or thicknesses, when other parameters were the same and magnetic resonance imaging （MRI） was performed respectively, or with different field of views （FOV） or coil when other parameters were the same. The distinction between groups was analyzed by SPSS10.0 with apparent diffusion coefficient （ADC）, quality index （QI） or signal-noise ratio （SNR）. RESULTS： As b value increased, liver ADC, QI and SNR of DWI became smaller and simultaneously （F= 292.87, 156.1, 88.23, P〈0.01）. QI of DWI was high, when bvalue was 10, 50 or 100 respectively, but the distinction between them was insignificant; when b value was 800, QI and SNR of DWI were low. QI and SNR of DWI had no significant difference between TR = 4 000, 6 000 and 8 000. QI of DWI with 2 mm thickness was bigger than that with 5 mm thickness （t = 3.04, P〈0.01）, but SNR of DWI with 2 mm thickness was significantly smaller （t = -17.86, P〈0.01）. SNR of MRI with knee joint coil was obviously bigger than that with cranium coil It = -5.77 （TlWI） or -4.02 （T2WI）, P〈0.01], but QI of MRI was smaller on the contrary It = 7.10 （TlWI） or 3.97 （T2WI）, P〈0.01]. When FOV was enlarged gradually, SNR of MRI increased IF= 85.81 （T1WI） or 221.96 （T2WI）, P〈0.01], but QI firstly increased, then decreased IF= 68.67 （TlWI） or 69.46 （T2WI）, P〈0.01] and QI of MRI was the biggest when FOV was 20 crux15 cm. CONCLUSION： The scanning technique is very important in DWl of rabbit liver and the overall quality of DWl with b （100 s/mm2）, thickness （2 mm）, cranium coils and FOV（20 cm×15 cm） was best in our study, when other parameters were the same.

Characteristics of liver on magnetic resonance diffusion-weighted imaging:Dynamic and image pathological investigation in rabbit liver VX-2 tumor model

AIM： To investigate dynamical and image pathological characteristics of the liver on magnetic resonance （MR） diffusion-weighted imaging （DWI） in the rabbit VX-2 tumor model. METHODS： Forty New Zealand rabbits were included in the study and VX-2 tumor piece was implanted intrahepatically. Fifteen animals received two intrahepatic implantations while 25 had one intrahepatical implantation. DWI, T1- and T2-weighted of magnetic resonance imaging （MRI） were carried out on the 7th and the 14th d after implantation and DWI was conducted, respectively on the 21th d. Ten VX-2 tumor samples were studied pathologically. RESULTS： The rate of lump detected by DWI, TlWI and T2WI was 78.7%, 10.7% and 53.5% （X^2 =32.61, P 〈 0.001） on the 7th d after implantation and 95.8%, 54.3% and 82.9% （X^2 = 21.50, P 〈 0.001） on the 14th d. The signal of most VX-2 tumors on DWI was uniform and it was equal diffusion coefficient （ADC）. did not decrease on the 7th on the map of apparent The signal of VX tumors d after implantation, most of them slowly growing during the week following implantation without significant cell dying within the tumor. VX-2 tumors grew increasingly within 14 d after implantation but the signal of most VX-2 tumors on DWI or on the map of ADC was uniform or uneven and ADC of VX tumors decreased obscurely or slightly because tumor necrosis was still not obvious. On the 21th d after implantation, the signal of most VX-2 tumors on DWI or on the map of ADC was uneven because tumor necrosis was evident and ADC of VX-2 tumor necrotic areas decreased. The areas of viable cells in VX-2 tumors manifested a high signal on DWI and a low signal on the map of ADC. The areas of dead cells or necrosis in VX-2 tumors manifested low signals on DWI and low, equal or high signals on the map of ADC but they manifested high signals on DWI and on the map of ADC at the same time when the areas of necrotic tumor became liquefied or cystic. The border of tumors on DWI appeared gradually distinct and internal signals of tumor became progressively uneven. CONCLUSION： The manifestations of viable, necrotic and liquefied or cystic areas in VX-2 tumors on DWI are typical and DWI is of significant and potential values in clinical application in both the early detection and diagnosis of liver tumors.

Identification of Health and Welfare Parameters for Rabbit Production and Definition of an Evaluation Score

The knowledge on rabbit welfare may be improved by the use of correct tools for monitoring the different aspects of rabbit industrial farming. Therefore, the aim of this study was to define parameters related to health and welfare of animals in industrial farms with intensive husbandry. Health, management, environmental and productive parameters were firstly characterized and then a protocol to assess welfare of rabbits was define. The research was conducted on 8 industrial farms from 2004 to 2007 and around 30 inspections were done in each farm. At each visit, the health conditions were established by： （1） necropsy on animals of different productive category; （2） specific laboratory investigations based on the lesions observed; （3） checking the presence of parasites in environmental faecal samples; （4） bacteriological examination of vaginal, nasal and rectal swabs of rabbit of different age. The immune conditions and the efficacy of vaccinations were measured by determining anti-Myxomatosis and anti-Rabbit Haemorrhagic Disease antibodies using competitive ELISAs, and anti-Encephalitozoon cunicoli antibodies by immunocarbonassay. The environmental conditions were evaluated by measuring air temperature, relative humidity, ammonia concentration and bacterial/fungal count. Finally the productive parameters were also recorded and elaborated. All the entered values were then utilized for defining a score system to establish health and welfare conditions.

Development and characterization of urethral stricture model in rabbits

Objective： To establish an experimental model of urethral stricture in rabbits. Methods： A total of 21 adult male New Zealand rabbits were included into group. After intravenous anesthesia, urethroscopy was performed with a pediatric resectoscope （F13）. Fifteen animals were randomly selected as the study group. A lcm-long circumferential electrocoagulation of the bulbar urethra was performed to these animals until ulceration of the mucosa. The remaining 6 animals underwent video urethroscopy without electrocoagulation, serving as controls. On the 30th day, retrograde urethrogram and urethroscopy were performed to evaluate urethral stricture formation, histological examinations （HE and Sirius Red staining） were done to assess urethral pathological change. Results： Two rabbits in study group died and no death occurred in controls. Based on urethrogram and urethroscopy, no rabbits in control group developed urethral stricture, while significant stricture formation was observed in every case of the study group. Histological examination showed a normal urethra in control cases, while at stricture site of the study group extensive fibrosis of muscle and submucous tis High collagen expression in fibrosis tissue was assayed sue by was observed with a large number of fibroblasts infiltration Sirius Red staining. Conclusion： A lcm-long endoscopic electrocoagulation can successfully induce urethral stricture formation in rabbit models. This method offers an ideal animal model for the fundamental and clinical study of urethral stricture

A Correlative Study of CT, MR and Pathology in Rabbit Liver after Embolization by a China-Formulated Lipiodol Emulsion

OBJECTIVE To explore the MR characteristics following lipiodol retention in rabbit liver and to evaluate the sensitivity of CT （CT value 〉400 HU） and MR in displaying the hepatic degeneration and necrosis following embolization. METHODS Thirty-two rabbits were randomly divided into 3 groups. In the control group （n=8）, 2 ml of normal saline was injected into the right branch of the portal vein. In the first experimental group（n= 12）, 4 ml of lipiodol emulsion was injected into the main portal vein. In the second experimental group （n= 12）, 2 ml of lipiodol emulsion was injected into the right branch of the portal vein. CT and MR images were obtained before and after surgery in each group. The histopathologic condition was determined for all liver tissue specimens. RESULTS In the control group, CT and MR did not show any significant changes in the livers after surgery. After the operations in the experimental groups, the regional CT attenuation was 601±101 HU in the largest slice, which had no abnormal signals on T1Wl and T2Wl. In the first group, histologic examinations showed there were concentrated lipiodol droplets around the portal areas. In the second group, serious degeneration and necrosis in the right hepatic lobe occurred in 9 rabbits. T1Wl displayed homogenous or non-homogenous low signals and T2Wl mainly displayed a high signal. However, these pathologic changes did not appear on CT scanning due to high attenuation of the lipiodol. CONCLUSION There were no remarkable hepatic changes on MR in rabbits following good retention of the formulated lipiodol emulsion mixture of lipiodol and urografin（CT value 〉 400 HU）. MR displayed serious degeneration and necrosis of the liver following embolization.

Toxicity of Alum to Newzealand Rabbits

This study was considered to assess the risk of alum which is used in Sudan for drinking water treatment purposes for a long period without toxicity freedom records .Newzealand rabbits were chosen for animal phase trials, divided into 3 groups. One group was the undosed controls. Test groups were given alum at dose rates of 1% and 20% respectively for two groups after an adaptation period. Clinical signs were observed together with postmortem and histopathological examinations. Chemical investigations included enzymatic, metabolic, electrolyte and hematological changes. The test rabbits demonstrated low voice, inappitence, whitish salivation, watery diarrhea and recumbence followed by emphysematous, lungs, electrolyte imbalance, renal dysfunctions, stiff focal inflammation of the empty intestines and congested liver with white spots. The control group was normal .On atomic absorption only the lungs kept residual alum, while the livers washed- out the substance ,may be via bile .Alum -dosed rabbits showed necrosis in the cortex and medulla of the kidney, emphysema in the lungs and necrosis in the hepatocytes. On evaluation of the above results, alum was considered to be toxic to Newzealand rabbits at dose rates tried.

Expression of Hsp70 and Caspase-3 in rabbits after se- vere traumatic brain injury

Objective： To investigate the expres- sion of Caspase-3 and Hsp70 in rabbits after severe trau- matic brain injury （TBI） and to explore the feasibility of its application in estimation of injury time in forensic medicine. Methods： Arabbit model of heavy TBI was developed by high velocity impact on the parietal bone with an iron stick. Totally 8 healthy adult New Zealand white rabbits were randomly divided into control group （n=2） and injury group （n=6）. Four hours after injury, tissue specimens from the parietal lobe, temporal lobe, occipital lobe, cerebellum and brainstem were harvested to detect the expression of Hsp70 and Caspase-3 by immunohistochemistry. Besides, the gray values of cells positive for HspT0 and Caspase-3 were analyzed with an image analyzer. Results： Immunohistochemistry staining demonstrated a low level of Caspase-3 and Hsp70 expression in normal control group. While in injury group, both the Caspase-3 and Hsp70 expression was significantly elevated （P〈0.05）. Positive cells gathered around the lesion focus. Occipital lobe and cerebellum had fewer positive cells while temporal and brainstem had the fewest. Conclusion： The expression of Caspase-3 and HspT0 at an early stage following severe TBI is characteristic and can be applied to estimate the time of injury.

Protective effects of ischemic postconditioning on intestinal mucosa barrier function in rabbits with crush injury of hind limb： an experimental study

Objective： To explore the protective effects of two types of ischemic postconditioning （IP） on intestinal mucosa barrier in rabbits with crush injury of the hind limb. Methods： This study was conducted between August and December 2008 in the Department of Trauma Surgery, Daping Hospital, Third Military Medical University, Chongqing, China. The model of crush injury to the hind limb of rabbits was firstly developed by a 25 kg object with the right hind limbs fixed by wooden splints, and then two types of IP were established, including occluding/opening the common iliac artery and vein alternatively （traditional IP, IP A） and binding/loosening the proximum of the injured hind limb altematively （modified IP, IP B）. Thirty-six male New Zealand white rabbits were randomly divided into three groups： IP A group, IP B group and control group, with 12 rabbits in each group. The serum levels of diamine oxidase （DAO） and intestinal fatty acid-binding protein （I-FABP） were detected at 2, 6, 12 and 24 hours after injury. Pathologi- cal changes of ileum were examined at 24 hours after injury. Results： The serum levels of I-FABP at 2, 6, 12 and 24 hours after injury in both IPA and IP B groups had a significant decrease, compared with control group. DAO levels also showed the same change trend at 2 and 6 hours after injury, but showed no significant difference between two IP groups. No difference in pathological changes of ileum was found among the three groups. Conclusions： IP can protect intestinal mucosa barrier function on the model of hind limb crush injury in rabbits. Meanwhile the modified IP B shows the same protection as the traditional IP A, and is worth applying in clinic.