Effects of the Fusarium toxin deoxynivalenol from naturally contaminated wheat given subchronically or as one single dose on the in vivo protein synthesis of peripheral blood lymphocytes and plasma proteins in the pig

Trichothecenes, such as deoxynivalenol (DON), are known to inhibit the protein synthesis in vitro by binding at the 60S subunit of eukaryotic ribosomes. Therefore, cells and tissues with high protein turnover, such as lymphocytes and the liver (albumin and fibrinogen synthesis), were suggested to react most sensitively to DON. However, to the author's knowledge this observation was not proven in vivo in pigs, which were regarded as the farm animals most susceptible to DON. A total of 31 castrated male, crossbred German Landrace x Pietrain pigs weighing approx. 40 kg were fed a DON contaminated diet (5.7 mg/kg) either acutely (one single dose) or subchronically (4 weeks) or a control diet (0.1 mg/kg). In addition, one group received an intravenous injection of 53 microg DON/kg LW. One hour after feeding, a "flooding dose" of the stable isotope l-[(2)H(5)]-phenylalanine (125 mg/kg LW) was given and frequent blood samples (permanent catheter) were collected over a 60 min period. The molar percent excess (MPE) of plasma free and protein-bound phenylalanine were measured by GC/MS. No differences could be observed in the plasma concentrations of total protein, albumin, fibrinogen and serum enzymes between the groups. On the other hand, fractional synthesis rates (FSR, %/d) of albumin were significantly decreased by 43%, 45% and 26% and FSR of lymphocytes declined by 27%, 19% and 24%, whereas fibrinogen was not significantly affected after subchronic or one single oral and intravenous DON exposure, respectively. Additionally, the absolute synthesis rate (ASR, g/d) of albumin and the proportion of albumin to total body protein synthesis were reduced in the same manner, whereas the albumin secretion time ranged between 6.8 and 34.4 min and was not affected by treatment. In conclusion, the flooding dose technique appeared to be suitable for distinguishing DON-related effects on the protein synthesis, while determination of plasma protein concentrations seemed not to be an appropriate parameter.     

乳猪心钠素单克隆抗体的研究

以乳猪ＡＮＰ作为免疫原，通过杂交瘤技术建立了３株稳定分泌特异ＡＮＰ单克隆抗体的细胞株，对其所分泌单抗的生物学特性进行了鉴定，单抗滴度为（１～６）×１０－７，两种为ＩｇＧ１型，一种为ＩｇＧ２ａ型，所分泌的单抗能识别不同的抗原表位。     

合肥市屠宰生猪主要微生物学指标调查研究

目的：了解合肥市定点屠宰场生猪屠宰加工产品的卫生质量以及加工生产的卫生状况。方法：应用国标法对5个定点生猪屠宰场500份生猪胴体体表样品及200份胴体肉样进行菌落总数、大肠菌群和沙门菌的检测。结果：生猪胴体肉样菌落总数和大肠菌群的总超标率达46%和22.5%;生猪胴体体表样品和肉样沙门菌检出率分别为24.2%和17%;大肠菌群和沙门菌之间呈现正相关。结论：合肥市生猪胴体的卫生质量急需提高,屠宰生产加工水平亟待改善,在肉品生产过程中重视大肠菌群的控制则有利于降低沙门菌的污染程度,实施宰前管理和宰前检验是保证病健隔离分宰,减轻对加工环境和产品污染的重要环节。     

复合角化细胞人工皮肤的实验研究——小香猪角化细胞库的构建

目的小香猪皮肤角化细胞常作为种子细胞运用于多种生物复合材料中，本研究旨在通过对小香猪角化细胞获取、培养及传代的研究，为生物膜修复皮肤缺损奠定基础。方法采用中性蛋白酶和胰蛋白酶联合消化法分离小香猪角化细胞，然后接种、传代，观察角化细胞形态，并绘制生长曲线。同时，将角化细胞进行冻存与复苏，观察其特性。结果小香猪角化细胞呈“铺路石”样生长，可连续传代，第1代到第4代保持了旺盛的增长趋势，且细胞形态良好，与原代细胞无明显区别，第5代之后细胞生长缓慢，不宜传代。冻存、复苏后的角质形成细胞保持了与原代细胞相同的生长状态．并具有继续传代能力。从细胞生长曲线上可以看出角化细胞的生长过程经历了潜伏期、指数生长期、停滞期二三个阶段。结论小型香猪角质细胞库的构建为组织工程化皮肤的临床应用奠定了前期基础。     

Tauroursodeoxycholate ameliorates reperfusion injury after pig liver transplantation

Reperfusion injury is a serious problem after clinical liver transplantation, often leading to dys- or even non-function of grafts. The present study was designed to determine whether the hydrophilic bile salt tauroursodeoxycholate (TUDC), known to be hepatoprotective in cholestatic liver disease, mitigates reperfusion injury in an in vivo pig liver transplantation model. Liver transplantation was performed in 12 pigs after a preservation time of 8 h. TUDC was administered to donor and recipient animals, and saline to controls. Blood was drawn at different time points for determination of liver enzymes. Bile samples were collected, and bile flow (BF), and bile salt secretion rate (BSSR) determined. Samples of liver tissue and bile ducts were taken for assessment by light and electron microscopy. Liver enzymes were significantly lower in the TUDC group. BF and BSSR were significantly higher. Microscopy revealed better preservation of bile duct architecture of the TUDC-infused animals. We can conclude that infusions of TUDC in pig livers ameliorate reperfusion injury in vivo. The molecular basis for this finding may be the membrane stabilizing effect of TUDC. Further studies are warranted to clarify its effect. Received: 19 February 1999 Received after revision: 23 August 1999 Accepted: 16 September 1999     

The Anti-Non-Gal Xenoantibody Response to Xenoantigens on Gal Knockout Pig Cells Is Encoded by a Restricted Number of Germline Progenitors

Antibodies directed at non-gal xenoantigens are responsible for acute humoral xenograft rejection when gal knockout (GalTKO) pig organs are transplanted into nonhuman primates. We generated IgM and IgG gene libraries using peripheral blood lymphocytes of rhesus monkeys initiating active xenoantibody responses after immunization with GalTKO pig endothelial cells and used these libraries to identify IgV_H genes that encode antibody responses to non-gal pig xenoantigens. Immunoglobulin genes derived from the IGHV3–21 germline progenitor encode xenoantibodies directed at non-gal xenoantigens. Transduction of GalTKO cells with lentiviral vectors expressing the porcine α1,3 galactosyltransferase gene responsible for gal carbohydrate expression results in a higher level of binding of 'anti-non-gal' xenoantibodies to transduced GalTKO cells expressing the gal carbohydrate, suggesting that anti-non-gal xenoantibodies cross react with carbohydrate xenoantigens. The galactosyltransferase two gene encoding isoglobotriaosylceramide synthase (iGb3 synthase) is not expressed in GalTKO pig cells. Our results demonstrate that anti-non-gal xenoantibodies in primates are encoded by IgV_H genes that are restricted to IGHV3–21 and bind to an epitope that is structurally related to but distinct from the Gal carbohydrate.     

HF-Electro-Surgery, Ultrasound-Dissection or Laser for the Laparoscopic Cholecystectomy and for Liver-Wedge-Resection. An Experimental Study in Pigs

laparoscopic wedge-resection of the liver is performed in 6 pigs, in three of these a cholecystectomy is carried out during the same operation. The method of resection chosen was: Monopolar HF-current, ultrasound and laser (Nd:YAG-laser and Holmium:YAG-laser). The least damage to the healthy liver tissue was seen using the Holmium:YAG-laser. Healing (after18 days) was best when the Holmium:YAG-laser had been used. Cautery was worst in both tissue damage and delayed healing.     

Vishweshwaraiah Iron Steel Limited (VISL) fire disasters following steel converter blast, 30 July 2003

A fire disaster occurred in Vishweshwaraiah Iron Steel Limited (VISL), Bhadravathi, India on 30 July 2003. The steel converter containing 24,000 kg of liquid metal (pig iron) at very high temperature exploded. A total of 30 workers became victims. Seven persons died on the spot. Twenty-three victims were transferred to the VISL hospital; of these, six were transferred to the burns unit of the Kasturba Hospital, Manipal (180 km from VISL). All six treated at the burns unit suffered 3–65% total body surface area (TBSA) burn, two had external injuries and two had eye involvement. Out of the six patients admitted at the burns unit, two expired (one due to refractory shock and another due to pulmonary embolism). Out of four survivors, one underwent tangential excision; another underwent operation for removal of foreign body from both soles and the remaining two were managed conservatively. Of the four survivors, two who had eye injuries, one developed minute corneal opacities within 2 months. The total duration of hospital stay of survivors at the burns unit varied from 8 to 43 days. All the victims were counselled by VISL psychiatrists before resuming their duties. Except the one who developed mixed anxiety–depression disorder, all survivors returned to work. The article describes the mechanism of the incident, injuries sustained and suggestions in relation to future safety measures.     

Further development of the rat Pig-a mutation assay: measuring rat Pig-a mutant bone marrow erythroids and a high throughput assay for mutant peripheral blood reticulocytes

Recent studies indicate that the Pig-a assay is a promising tool for evaluating in vivo mutagenicity. We have developed novel rat Pig-a assays that facilitate measuring mutant frequencies in two early arising populations of blood cells, bone marrow erythroids (BMEs) and peripheral blood (PB) reticulocytes (RETs). In these assays, bone marrow cells of erythroid origin and PB red blood cells (RBCs) were identified using an antibody against rat erythroid-specific marker HIS49. In addition, RETs were selectivity enriched from PB using magnetic separation of cells positive for CD71, a transferrin receptor expressed on the surface of BMEs and RETs, but not on the surface of mature RBCs. With magnetic enrichment, more than 1 x 10(6) CD71-positive RETs could be evaluated by flow cytometry for Pig-a mutant frequency within 5 to 8 min. CD59-deficient RET and BME frequencies of more than 100 x 10(-6) and 80 x 10(-6) were detected 1 week after treating rats with 40 mg/kg N-ethyl-N-nitrosourea; by comparison, the frequency of CD59-deficient total RBCs in these rats was 13.2 x 10(-6). The frequency of spontaneous Pig-a mutant RETs and BMEs was less than 5 x 10(-6) and 15 x 10(-6), respectively. Since approximately 98% of nucleated cells in the BME fraction were erythroblasts, it should be possible to use BMEs to determine the spectrum of CD59-deficient Pig-a mutations in cells of erythroid lineage. Conducting concurrent Pig-a assays on RETs and BMEs may be useful for evaluating the in vivo mutagenicity of chemicals, especially when prolonged mutant manifestation is not feasible or when the confirmation of mutation induction is necessary.     

Effects of active immunization against cholecystokinin 8 on performance, contents of serum hormones, and expressions of CCK gene and CCK receptor gene in pigs

This study was conducted to investigate the effects of active immunization against cholecystokinin 8 (CCK₈) on the content of serum CCK, expression of CCK, and CCK receptor gene in pigs. The subjects for this experiment were 15 pigs divided into three groups (5 pigs per group). The treated groups were immunized with CCK₈ conjugated to human serum albumin (HSA). The control group was immunized with same dosage of HSA. The average daily gain of pig fed with 250 μg CCK was significantly increased (P < 0.05), compared with the control group (0 μg CCK). The content of CCK₈, insulin, and leptin in serum was significantly (P < 0.05) decreased and the titer of CCK₈ antibody was significantly (P < 0.05) increased in treated groups compared to the control group. The levels of CCK gene and CCK receptor gene expression in jejunum, pituitary, and pancreas of the treated groups were significantly (P < 0.05) lower than that of the control group. It is concluded that optimal active immunization against CCK₈ could increase the content of CCK antibody and suppress CCK gene and CCK receptor gene expressions and in result improve feed intake and growth performance of pigs. Keying Zhang and Zhongbiao Yuan have contributed equally to this work.