双胍盐对柑桔青霉病防治效果试验

两年的抑菌、刻伤接种和果实贮藏试验表明,双胍盐对柑桔青霉病的防治效果与伊迈唑相接近,可作为苯并咪唑类的替换药剂。     

Identification of bovine viral diarrhea virus type 1 in yaks (Bos poephagus grunniens) in the Himalayan region

Since cattle are widely infected by bovine viral diarrhea virus (BVDV) in India, we searched for pestivirus infection in yaks. Of 71 pure and crossbred yaks from Himalayan region, pestivirus antigen was detected by Ag-ELISA in three animals. Pestivirus in leukocyte and cell culture isolated virus samples originating from positive yaks was also confirmed by RT-PCR using panpestivirus specific primers selected from 5'-untranslated region (5' UTR). The 5' UTR, N(pro) and E2 regions were sequenced and used for genetic typing. Phylogenetic analysis revealed that pestiviruses detected in three Himalayan yaks were similar genetically, belonging to BVDV-1. Antigenic characterisation of yak pestivirus also confirmed the typing as BVDV-1. This is the first report on the identification of BVDV type 1 in yaks.     

云南松松塔提取物对H22实体瘤小鼠模型的抑瘤作用

研究云南松松塔乙醇提取物(PEA)和碱水提取醇沉物(PED)对H22实体瘤小鼠的抑瘤作用。建立H22实体瘤小鼠模型,随机分组,灌胃给药,1次/d,给药10d。末次给药24h后,取血检测γ干扰素(IFN-γ)、白细胞介素-2(IL-2)、白细胞介素-4(IL-4)和白细胞介素-10(IL-10)含量;剥离肿瘤组织并称重,计算抑瘤率;检测肿瘤组织匀浆中环氧化酶-2(COX-2)和前列腺素E2(PGE2)含量;石蜡包埋HE染色观察肿瘤细胞病理组织学变化。结果显示,PEA和PED各剂量组小鼠平均肿瘤重量较模型组显著减小;最大抑瘤率分别达46.11%和58.05%。PEA和PED各剂量组小鼠外周血中IFN-γ和IL-2含量较模型组显著升高;IL-4和IL-10含量较模型组显著降低。PEA和PED各剂量组小鼠肿瘤组织中COX-2和PGE2含量较模型组显著减少;给药组正常肿瘤组织减少,有出血和坏死,脂肪组织增多。结果表明,PEA和PED可抑制H22实体瘤小鼠的肿瘤生长,其机制与调节Th1/Th2细胞平衡和抑制COX-2与PGE2的表达有关。     

Evidence for estrogen receptor expression during medullary bone formation and resorption in estrogen-treated male Japanese quails (Coturnix coturnix japonica)

The temporal expression of estrogen receptor (ER)-α and ER-β mRNA was examined in male Japanese quails. Femurs of quails receiving 17β-estradiol underwent RTPCR and histochemical analysis 1 to 15 days after treatment. Untreated quails were used as controls (day 0). Between days 0 and 5, cells lining the bone endosteal surface differentiated into osteoblasts, which in turn formed medullary bone. Expression of ER-α was already observed on day 0 and increased slightly during bone formation whereas ER-β was hardly detected throughout this process. After osteoclasts appeared on the medullary bone surface, this type of bone disappeared from the bone marrow cavity (days 7~15). ER-α expression simultaneously decreased slightly and ER-β levels remained very low. These results suggest that estrogen activity mediated by ER-α not only affects medullary bone formation but also bone resorption.     

A meta-analysis comparing the effect of PCV2 vaccines on average daily weight gain and mortality rate in pigs from weaning to slaughter

The aim of this investigation was, through a meta-analysis, to review the published literature concerning the effect of PCV2 vaccination on the average daily weight gain (ADG) and on the mortality rate in pigs from weaning to slaughter. The review was restricted to studies investigating the effect of vaccines against PCV2 published from 2006 to 2008, identified using computerised literature databases. Only studies that met the following criteria were included: commercial vaccines were used, pigs or pens were assigned randomly to vaccination versus control groups in herds naturally infected with PCV2, and vaccinated and non-vaccinated pigs were housed together. Furthermore, it was a requirement that sample size, age at vaccination, and production period were stated. The levels of ADG and mortality rate had to be comparable to those seen in modern intensive swine production. In total, 107 studies were identified; 70 were excluded because they did not fulfil the inclusion criteria and 13 were identical to results published elsewhere. A significant effect of PCV2 vaccination on ADG was found for pigs in all production phases. The largest increase in ADG was found for finishing pigs (41.5g) and nursery-finishing pigs (33.6g) with only 10.6g increase in the nursery pigs. Mortality rate was significantly reduced for finishing pigs (4.4%) and nursery-finishing pigs (5.4%), but not for nursery pigs (0.25%). Herds negative for PRRS had a significantly larger increase in ADG compared to herds positive for PRRS. The PRRS status had no effect on mortality rate.     

Influence of sodium diethyldithiocarbamate (Imuthiol) on lymphocyte function and growth in weanling pigs

Mitogen-stimulated lymphocyte proliferation, delayed-type hypersensitivity (DTH) reactions, interleukin-2 (IL-2) production, and growth performance were evaluated in 3-week-old pigs treated with imuthiol. Lymphocyte proliferative responses to Con A and PWM were reduced (P < 0.05) in pigs treated with imuthiol at 25 mg/kg; PHA proliferative responses were not influenced by imuthiol treatment. Imuthiol at 2.5 mg/kg and 25 mg/kg lowered IL-2 production when compared to saline-treated controls. Delayed-type hypersensitivity responses to PHA were higher in 25 mg/kg imuthiol-treated pigs; however, 2.5 mg/kg imuthiol-treated pigs had lower DHT reactions. Imuthiol at 2.5 mg/kg and 25 mg/kg reduced (P < 0.05) average daily feed intake. These data suggest that in vivo imuthiol treatment in pigs lowers lymphocyte proliferative responses, IL-2 production, and growth performance.     

Immunostimulatory effects of natural human interferon-alpha (huIFN-α) on carps Cyprinus carpio L.

Human interferon-α (huIFN-α) is an important immunomodulatory substance used in the treatment and prevention of numerous infectious and immune-related diseases in animals. However, the immunostimulatory effects of huIFN-α in fish remain to be investigated. In the current study, the immune responses of the carp species Cyprinus carpio L. to treatment with huIFN-α were analyzed via measurement of superoxide anion production, phagocytic activity and the expression of cytokine genes including interleukin-1β, tumor necrosis factor-α and interleukin 10. Low doses of huIFN-α were administered orally once a day for 3 days, and sampling was carried out at 1, 3 and 5 days post-treatment. Our results indicate that a low dose of huIFN-α significantly increased phagocytic activity and superoxide anion production in the carp kidney. The huIFN-α-treated fish also displayed a significant upregulation in cytokine gene expression. The current study demonstrates the stimulatory effects of huIFN-α on the carp immune system and highlights the immunomodulatory role of huIFN-α in fish.