三代头孢菌素致尿毒症患者中枢神经系统不良反应的护理

目的总结三代头孢菌素引起尿毒症患者中枢神经系统不良反应的护理经验。方法对12例尿毒症患者使用三代头孢菌素后出现神经、精神症状,进行临床分析并采取相应的防护措施。结果 12例均及时停药,给予对症、支持治疗,其中4例维持性血液透析患者各增加1次透析、6例进行急诊血液透析,所有病例症状消失。结论尿毒症患者应用三代头孢菌素时需详细询问病史,严密观察用药反应,出现中枢神经系统不良反应后及时停药并积极采取相应的治疗护理措施,可避免严重并发症发生。     

Maintenance of cell volume in the central nervous system

Maintenance of the ionic and osmotic composition and volume of intra- and extracellular fluids in the brain is crucial for normal functioning of the central nervous system (CNS). Osmoregulation in the CNS is mediated by solute and water transport across the blood-brain barrier, choroid plexus and plasma membrane of glial cells and neurons. Despite its clinical and physiological significance, however, little is known about the underlying cellular and molecular mechanisms by which CNS osmotic and ionic balance is maintained. In this review, I will discuss our current understanding of cell volume regulation in the CNS and how it relates to various disease processes, such as hyponatremia, renal failure and hypernatremia. A detailed understanding of brain osmoregulatory processes represents a fundamental physiological problem and is required for the treatment of numerous disease states, particularly those encountered in the practice of nephrology.     

Prevalence and trend analysis of antimicrobial resistance in clinical Escherichia coli isolates collected from diseased pigs in the USA between 2006 and 2016

Antimicrobial resistance (AMR) is an emerging threat to both human and animal health. Antimicrobial use and resistance in food animal production, including swine, has received increased scrutiny as a source of resistant foodborne pathogens. Continuous surveillance of AMR in bacterial isolates of swine origin can guide in conservation of antimicrobials used in both human and swine medicine. The objective of this study was to evaluate the prevalence and trends of the phenotypic AMR in Escherichia coli of swine origin isolated from clinical samples at the Minnesota Veterinary Diagnostic laboratory between 2006 and 2016. The prevalence of resistance to ampicillin, tetracyclines and sulphadimethoxine remained greater than 50% throughout the period. There was a drastic change in enrofloxacin resistance, increasing from less than 1% to more than 20% between 2006 and 2016 (annual relative increase of 57% between 2006 and 2013 and 16% between 2013 and 2016). The prevalence of resistance to other antimicrobials remained constant (ceftiofur, oxytetracycline and chlortetracycline) or changed significantly (annual relative changes of less than 10%) for at least some time‐period between 2006 and 2016 (ampicillin, florfenicol, gentamicin, neomycin, sulphadimethoxine, trimethoprim‐sulphamethoxazole and spectinomycin). Rarefaction analysis revealed an increase in the number of unique combinations of AMRs per year. Network analysis was performed by estimating and plotting partial correlations between minimum inhibitory concentrations (MICs) of various antimicrobials. An increase in strength of these networks was observed, particularly in networks created after 2010, which can be indicative of increased multiple AMR in these isolates. These results provide valuable insight into the trends in AMR in E. coli of swine origin in the USA and act as supplementary information to the existing active AMR surveillance systems.     

Detection of atypical porcine pestivirus in Brazil in the central nervous system of suckling piglets with congenital tremor

Atypical porcine pestivirus (APPV ) has been detected in piglets with congenital tremor (CT ) from three different continents including North America, Europe and Asia. Thirteen piglets from four farms in two different states in Brazil with CT were sampled. Viral RNA was detected by quantitative real‐time PCR in the cerebellum or cerebellum and spinal cord in the 100% of the piglets with CT , and APPV was not detected in any tissue sample from clinically non‐affected piglets with the exception of the cerebellum of one piglet from Farm A. Piglets with CT had an odds ratio of 99.0 (95% CI 3.4, 2823.8; p  =  .0072) compared to piglets without CT to test positive for APPV by qRT ‐PCR . A subset of positive samples was selected for sequencing of the NS 3 gene. Phylogenetic analysis revealed that Brazilian sequences of the NS 3 formed an independent cluster and had the highest sequence identity with a sequence from the United States. This is the first identification of APPV infection in piglets with CT in South America.     

Effect of epinephrine on central nervous system and cardiovascular system toxicity of bupivacaine in pigs

To determine what effect the addition of epinephrine has on bupivacaine toxicity, toxic doses of bupivacaine were administered to awake spontaneously breathing pigs. Twenty animals were randomized to one of two groups. One group received an infusion of bupivacaine with epinephrine (5 micrograms/ml) at a rate of 2 mg.kg-1.min-1; the other received an infusion of plain bupivacaine at the same rate. Bupivacaine infusion was continued until cardiovascular collapse. Following cardiovascular collapse we attempted to resuscitate the animals via open chest cardiac massage and a standardized resuscitation protocol. The addition of epinephrine to bupivacaine significantly increased blood pressure and systemic vascular resistance but not heart rate or cardiac output early in the bupivacaine infusion. Epinephrine had no effect on the dose of bupivacaine that caused cardiovascular collapse (P = 0.1), on the plasma concentration of bupivacaine at collapse (P = 0.9), or on the ability to resuscitate animals following cardiovascular collapse. The addition of epinephrine decreased the dose of bupivacaine required to initiate cardiac dysrhythmias (P = 0.003). The first dysrhythmia experienced by the epinephrine group was second degree heart block, which contrasts with the premature ventricular and atrial dysrhythmias experienced by the plain group. The dose of bupivacaine that produced seizures was also reduced by the addition of epinephrine (P = 0.006). The addition of epinephrine to bupivacaine did not alter the dose of bupivacaine that caused cardiovascular collapse in awake spontaneously breathing pigs but did decrease the dose of bupivacaine that caused seizures and dysrhythmias.     

Spontaneous migration of a bullet in the central nervous system

An example of spontaneous migration of a metallic foreign body within the subarachnoid space is illustrated. An intracranial bullet is shown to move within the cisterns of the posterior fossa and then down the subarachnoid space of the spinal canal. The patient's symptoms correlate well with the movement of the foreign body.     

Development of a novel quantitative real‐time PCR assay with lyophilized powder reagent to detect African swine fever virus in blood samples of domestic pigs in China

African swine fever (ASF) is a devastating disease, which is causing huge economic losses in China. Therefore, it is urgent to provide a rapid, highly specific and sensitive diagnostic method for the detection of African swine fever virus (ASFV), the ASF infectious agent. In this study, a novel quantitative real‐time polymerase chain reaction (qPCR) assay with lyophilized powder reagents (LPR), targeting the major structural protein p72 gene, was established for the detection of ASFV. This assay had many advantages, such as saving time and money, good sensitivity and repeatability. The sensitivity of this assay was 100 copies/μl of ASFV plasmid templates, and the assay showed 10‐fold greater sensitivity than a qPCR assay recommended by OIE. Furthermore, specificity analysis showed that qPCR with LPR for ASFV had no cross‐reactivity with other important swine pathogens. In clinical diagnoses of 218 blood samples of domestic pigs in China, the positive rate of the diagnosis of ASFV by qPCR with the LPR and commercial kit reached 80.73% (176/218) and 76.61% (167/218) respectively. The coincidence rate between the two assays is 92.20% (201/218), and kappa value is 0.768 (p < .0001) by SPSS analysis. The overall agreement between the two assays was 95.87% (209/218). Further Pearson correlation and linear regression analysis showed a significant correlation between the two assays with an R² value of 0.9438. The entire procedure, from specimen processing to result reporting, can be completed within 2 hr. Our results demonstrated that the qPCR‐LPR assay is a good laboratory diagnostic tool for sensitive and efficient detection of ASFV.     

Surveillance of Bungowannah Pestivirus in the Upper Midwestern USA

Pestiviruses, a genetically and antigenically highly diverse group, include one of the most historically significant swine pathogens, that is, classical swine fever virus. In Australia, investigations into swine outbreaks characterized by neonatal mortality, stillbirths and mummified foetuses resulted in the discovery of a new pestivirus, Bungowannah virus. This finding raised the possibility that Bungowannah virus, or a variant thereof, was circulating in swine herds elsewhere in the World. If so, it raised the possibility of a pestivirus emerging as a new swine disease with unknown consequences for animal health and food safety. Thus, we developed three specific qRT‐PCR assays to evaluate tissue samples from undiagnosed cases of abortion or respiratory disease for evidence of Bungowannah virus. Examination of 64 samples collected between the Fall of 2007 and Spring of 2010 tested negative for all three genes examined. We conclude that Bungowannah‐like pestivirus is unlikely to be present in swine in the upper Midwestern USA.     

Differential effect of recombinant tissue plasminogen activator-induced thrombolysis in the central nervous system and systemic arteries

Recombinant tissue plasminogen activator (rTPA) has been more effective in inducing thrombolysis in laboratory studies of intracranial thrombosis than clinical studies of systemic or coronary thrombosis would indicate. To evaluate this discrepancy, 21 rabbits were subjected to embolic occlusion of the right internal carotid artery (ICA) by retrograde injection of a tin-tagged, 2-hour-old autologous clot through the external carotid artery with angiographic monitoring in the same manner as in a previously reported model. The emboli lodged intracranially at the bifurcation of the ICA in 10 animals and in the cervical ICA in 11 animals. Digital subtraction angiography confirmed total occlusion of the ICA in all animals. Treatment started one-half hour after embolization and consisted of a bolus of 0.5 mg/kg of rTPA followed by an infusion of 1 mg/kg/h for 2 hours. All of the animals with intracranial emboli and 6 of the animals with cervical emboli were treated intravenously. The remaining 5 animals with cervical emboli were treated by intracarotid infusion of the same dose of rTPA. In the intravenously treated group, serial digital subtraction angiography documented thrombolysis in 9 of the 10 animals with intracranial emboli and only 1 of the 6 with cervical emboli. Thrombolysis occurred in 4 of the 5 rabbits with cervical emboli treated with intracarotid rTPA. Intravenous rTPA therapy produced a significantly (P less than 0.01) higher rate of thrombolysis in intracranial as compared to cervical thrombus.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of midazolam and diazepam premedication on central nervous system and cardiovascular toxicity of bupivacaine in pigs

To determine the effect of benzodiazepine premedication on central nervous system and cardiovascular effects of bupivacaine, the authors administered toxic doses of bupivacaine to awake spontaneously breathing pigs after intravenous premedication with midazolam (0.06 mg/kg), diazepam (0.15 mg/kg), or saline. Five minutes after administration of one of these solutions, they began an infusion of bupivacaine at 2 mg.kg-1.min-1. The bupivacaine infusion was continued until cardiovascular collapse. They then attempted to resuscitate the animals via open chest cardiac massage and a standard resuscitation protocol. Premedication with midazolam or diazepam significantly delayed the onset of ventricular dysrhythmias (P less than 0.05), decreased the incidence of seizures (P less than 0.05), and prevented the increase in blood pressure and heart rate following bupivacaine infusion (P less than 0.05). Benzodiazepine premedication did not affect the dose of bupivacaine or the blood concentration required to produce cardiovascular collapse. The ability to resuscitate animals premedicated with midazolam did not differ from control; however, significantly fewer animals premedicated with diazepam were resuscitated (P less than 0.05). A clinically relevant observation was that almost all animals premedicated with a benzodiazepine progressed directly to cardiovascular collapse without first manifesting seizures.