当前猪病流行动态与防控对策

我国是猪群生产和消费大国,产量和销量在世界首屈一指。毋庸置疑,这直接促进了养猪业迅速发展。然而,近年来,猪群流行病频发,严重制约了该产业发展。本文对猪群病流行现状和动态作以阐释分析,并试做出防控措施,以期参考。

Peritoneal carcinomatosis of colorectal origin:Incidence,prognosis and treatment options

Peritoneal carcinomatosis (PC) is one manifestation of metastatic colorectal cancer (CRC). Tumor growth on intestinal surfaces and associated fluid accumulation eventually result in bowel obstruction and incapacitating levels of ascites, which profoundly affect the quality of life for affected patients. PC appears resistant to traditional 5-fluorouracil-based chemotherapy, and surgery was formerly reserved for palliative purposes only. In the absence of effective treatment, the histori-cal prognosis for these patients was extremely poor, with an invariably fatal outcome. These poor outcomes likely explain why PC secondary to CRC has received little attention from oncologic researchers. Thus, data are lacking regarding incidence, clinical disease course, and accurate treatment evaluation for patients with PC. Recently, population-based studies have revealed that PC occurs relatively frequently among patients withCRC. Risk factors for developing PC have been identi-fied:right-sided tumor, advanced T-stage, advanced N-stage, poor differentiation grade, and younger age at diagnosis. During the past decade, both chemother-apeutical and surgical treatments have achieved prom-ising results in these patients. A chance for long-term survival or even cure may now be offered to selected patients by combining radical surgical resection with intraperitoneal instillation of heated chemotherapy. This combined procedure has become known as hy-perthermic intraperitoneal chemotherapy. This edito-rial outlines recent advancements in the medical and surgical treatment of PC and reviews the most recent information on incidence and prognosis of this disease. Given recent progress, treatment should now be considered in every patient presenting with PC.

Acute pancreatitis:Etiology and common pathogenesis

Acute pancreatitis is an inflammatory disease of the pancreas.The etiology and pathogenesis of acute pancreatitis have been intensively investigated for centuries worldwide.Many causes of acute pancreatitis have been discovered,but the pathogenetic theories are controversial.The most common cause of acute pancreatitis is gallstone impacting the distal common bile-pancreatic duct.The majority ofinvestigators accept that the main factors for acute billiary pancreatitis are pancreatic hyperstimulation and bile-pancreatic duct obstruction which increase pancreatic duct pressure and active trypsin reflux.Acute pancreatitis occurs when intracellular protective mechanisms to prevent trypsinogen activation or reduce trypsin activity are overwhelmed.However,little is known about the other acute pancreatitis.We hypothesize that acute biliary pancreatitis and other causes of acute pancreatitis possess a common pathogenesis.Pancreatic hyperstimulation and pancreatic duct obstruction increase pancreatic duct pressure,active trypsin reflux,and subsequent unregulated activation of trypsin within pancreatic acinar cells.Enzyme activation within the pancreas leads to auto-digestion of the gland and local inflammation.Once the hypothesis is confirmed,traditional therapeutic strategies against acute pancreatitis may be improved.Decompression of pancreatic duct pressure should be advocated in the treatment of acute pancreatitits which may greatly improve its outcome.

Effect of Maternal Antibodies on the Pathogenesis of Avian Reovirus Infections in Broiler Chickens Using Real-Time Reverse Transcriptase Polymerase Chain Reaction

The effect of maternal antibodies on the pathogenesis of avian reovirus （ARV） was studied in commercial and specific pathogen free broilers （SPF） using a real-time reverse transcriptase （RT）-polymerase chain reaction （PCR） assay, along with the incidence and severity of morbidity, mortality, and gross lesions. ARV RNA was detected in cloacal swabs in both bird groups from the first day throughout the 21 days experiment. Commercial broiler chickens, which had high maternal antibodies against ARV, showed minimum clinical signs, gross lesions, and lower numbers of birds with viral RNA excretion, whereas specific pathogen free （SPF） broiler chickens, which did not have antibody against ARVs, had 30% mortality, more severe signs, and higher numbers of birds excreting viral RNA. The highest peak of SPF birds excreting viral RNA occurred during the time of maximum mortality. The protective effect of maternal antibody on ARV pathogenesis in broiler chickens correlated with the detection of ARV RNA using the real-time RT-PCR.

Iatrogenic Tumor Implantation

Iatrogenic tumor implantation is a condition that results from various medical procedures used during diagnosis or treatment of a malignancy.It involves desquamation and dissemination of tumor cells that develop into a local recurrence or distant metastasis from the tumor under treatment.The main clinical feature of the condition is nodules at the operation's porous channel or incision,which is easily diagnosed in accordance with the case history.Final diagnosis can be made based on pathological examination.Tumor implantation may occur in various puncturing porous channels,including a laparoscopic port,abdominal wall incision,and perineal incision,etc.Besides a malignant tumor, implantation potential exists with diseases,such as a borderline tumor and endometriosis etc.Once a tumor implantation is diagnosed,or suspected,surgical resection is usually conducted. During the diagnosis and treatment of diseases,avoiding and reducing iatrogenic implantation and dissemination has been regarded as an important principle for surgical treatment of tumors.In a clinical practice setting,if possible,excisional biopsy should be employed,if a biopsy is needed.Repeated puncturing should be avoided during a paracentesis.In a laparoscopic procedure,the tissue is first put into a sample bag and then is taken out from the point of incision.After a laparoscopic procedure,the peritoneum,abdominal muscular fasciae,and skin should be carefully closed,and/or the punctured porous channel be excised.In addition,the sample/tissue should be rinsed with distilled water before surgical closure of the abdominal cavity, allowing the exfoliated tumor cells to swell and rupture in the hypo-osmolar solution.Then surgical closure can be conducted following a change of gloves and equipment.The extent of hysteromyomectomy should as far as possible be away from the uterine cavity.The purpose of this study is to make clinicians aware of the possibility of tumor implantation and to give special attention to avoid,or reduce iatrogenic implantation during a surgical procedure.

QUALITATIVE STUDY FOR A MULTI-DRUG RESISTANT TB MODEL WITH EXOGENOUS REINFECTION AND RELAPSE

One tuberculosis transmission model is formulated by incorporating exogenous reinfec- tion, relapse, and two treatment stages of infectious TB cases. The global stability of the unique disease-free equilibrium is obtained by applying the comparison principle if the effective reproduction number for the full model is less than unity. The existence and stability of the boundary equilibria are given by introducing the invasion reproduction numbers. Furthermore, the existence and local stability of the endemic equilibrium are addressed under some conditions.