A comparison of in situ hybridization and immunohistochemistry for the detection of a new porcine circovirus in formalin-fixed tissues from pigs with post-weaning multisystemic wasting syndrome (PMWS)

Post-weaning multisystemic wasting syndrome (PMWS) is a recently identified condition affecting pigs in North America and Europe. Porcine circovirus antigen and nucleic acid have been demonstrated associated with lesions, and a new porcine circovirus designated PCV2 has been recovered from tissues of these animals. In this study, in situ hybridisation and immunohistochemical protocols were developed, optimized and compared for their relative sensitivity in detecting PCV2 antigens and nucleic acid in tissues from cases of PMWS that had been fixed for up to 6 months in formalin. For both immunohistochemistry and in situ hybridization, an increase in specific signal was observed following increased exposure to both protease XIV and proteinase K. Maximum signal and minimal loss of tissue morphology was seen after 40 min treatment with protease XIV (0.5 mg/ml). After optimisation, a comparison of these techniques on sequential sections demonstrated that both techniques successfully detected antigen or nucleic acid in all of the tissues examined. More positive cells, with increased signal intensity, were detected following immunohistochemistry.     

Suppression of Heavy Drinking and Alcohol Seeking by a Selective ALDH-2 Inhibitor

Background: Inherited human aldehyde dehydrogenase 2 (ALDH‐2) deficiency reduces the risk for alcoholism. Kudzu plants and extracts have been used for 1,000 years in traditional Chinese medicine to treat alcoholism. Kudzu contains daidzin, which inhibits ALDH‐2 and suppresses heavy drinking in rodents. Decreased drinking due to ALDH‐2 inhibition is attributed to aversive properties of acetaldehyde accumulated during alcohol consumption. However, daidzin can reduce drinking in some rodents without necessarily increasing acetaldehyde. Therefore, a selective ALDH‐2 inhibitor might affect other metabolic factors involved in regulating drinking. Methods: Aldehyde dehydrogenase 2 inhibitors were synthesized based on the co‐crystal structure of ALDH‐2 and daidzin. We tested the efficacy of a highly selective reversible ALDH‐2 inhibitor, CVT‐10216, in models of moderate and high alcohol drinking rats. We studied 2‐bottle choice and deprivation‐induced drinking paradigms in Fawn Hooded (FH) rats, operant self‐administration in Long Evans (LE), FH, and inbred P (iP) rats and in cue‐induced reinstatement in iP rats. We also assayed blood acetaldehyde levels as well as dopamine (DA) release in the nucleus accumbens (NAc) and tested possible rewarding/aversive effects of the inhibitor in a conditioned place preference (CPP) paradigm. Results: CVT‐10216 increases acetaldehyde after alcohol gavage and inhibits 2‐bottle choice alcohol intake in heavy drinking rodents, including deprivation‐induced drinking. Moreover, CVT‐10216 also prevents operant self‐administration and eliminates cue‐induced reinstatement of alcohol seeking even when alcohol is not available (i.e., no acetaldehyde). Alcohol stimulates DA release in the NAc, which is thought to contribute to increased drinking and relapse in alcoholism. CVT‐10216 prevents alcohol‐induced increases in NAc DA without changing basal levels. CVT‐10216 does not show rewarding or aversive properties in the CPP paradigm at therapeutic doses. Conclusion: Our findings suggest that selective reversible ALDH‐2 inhibitors may have therapeutic potential to reduce excessive drinking and to suppress relapse in abstinent alcoholics.     

Prolonged survival with a remnant kidney

Surgical ablation of five-sixths renal mass in Munich-Wistar rats fed a high protein diet leads to focal sclerosis in the remnant kidney and progressive renal failure. Experimental data suggest that this injury results from intraglomerular hypertension and/or chronic glomerular hyperfiltration. Data in humans largely are limited to patients with unilateral renal agenesis or uninephrectomy, either for unilateral renal disease or for kidney transplant donation. Isolated case reports have documented focal sclerosis and progressive renal failure in two patients with a remnant kidney. To obtain data in humans with a remnant kidney, we surveyed more than 800 urologists and nephrologists in the United States and abroad. Criteria for inclusion in the study were (1) surgical resection (in one or more operations) resulting in the presence of a remnant kidney; and (2) an adequate period of follow-up, defined as 5 years or greater. A total of 13 patients were identified (from 13 different centers). Twelve patients had renal cancer and one had tuberculosis. Six patients were observed for 10 or more years postoperatively and all have stable serum creatinine levels of less than 270 mumol/L (3.0 mg/dL); two of these six patients are now more than 25 and 30 years postoperation. The other seven patients, observed for 5 to 7 years, have serum creatinine levels less than 270 mumol/L (3 mg/dL), while one has an increasing serum creatinine level. The two longest surviving patients both have undergone successful pregnancy with no overall change in serum creatinine. These observations demonstrate that it is possible for humans to survive more than 30 years with a stable serum creatinine, despite the presence of only a remnant kidney.     

Miliary tuberculosis: A complication of intravesical BCG treatment

A case of miliary tuberculosis following intravesical bacillus Calmette-Guerin (BCG) treatment is described.     

Stage I nonseminomatous germ-cell testicular cancer — management options and risk-benefit considerations

Summary The results obtained with primary retroperitoneal lymph-node dissection (RPLND) in 464 patients with clinical stage A nonseminomatous germ-cell (NSGC) testicular cancer over a period of 25 years (1965–1989) were reviewed. Results were analyzed in clinical terms and subdivided into early (1965–1978) and contemporary (1979–1989) findings so as to be comparable with series using radiotherapy or surveillance. Between 1965 and 1978 (86 clinical stage A patients), the overall relapse rate of 15% (n=13) was similar to that obtained in radiotherapy series but the survival (98.8% after RPLND) was superior to that achieved with irradiation (87%). From 1979 to 1989, 378 clinical stage A cases had primary RPLND, of whom 29% (n=111) had cancerous nodes. The relapse rate for pathological stage A patients (n=267) was 11% and two patients died. The rate of relapse for pathological stage B patients who did not receive adjuvant chemotherapy was 32%. No relapse was seen among 46 pathological stage B patients given postoperative adjuvant chemotherapy. The mortality of 0.7% observed among 378 clinical stage A RPLND cases was lower than the 2% value reported in surveillance series. Although not statistically significant, these consistent results reported for two eras (pre- and postplatinum) spanning a period of 25 years suggest a sound basis for the surgical approach. The anatomic and medical principles in oncology, which have supported this approach, remain cogent today. They are discussed herein. Now that nerve-sparing techniques have been developed, the one long-term morbidity of RPLND (i.e., anejaculation) can be avoided. It would seem appropriate to have nerve-sparing RPLND techniques in any armamentarium dealing with clinical stage A disease.     

Simulation studies of the CA3 hippocampal subfield modelled as an attractor neural network

Real neuronal networks in the brain utilize networks of neurons with graded not binary firing rates. A theoretical analysis of the operation of autoassociative networks with neurons with graded firing rates has therefore been developed. The present simulation study was performed in order to investigate the operation of such a network with values for the asymmetric diluted neuronal connectivity typical of some brain regions such as the hippocampus, which are outside the range to which the theoretical analysis strictly applies. We report that, in line with theoretical predictions, the amount of information that can be retrieved is relatively independent of the resolution of the stored patterns (binary, ternary, decimal, or fifty-fold). The implication of this is that if the network stores many graded patterns, which it can, then the retrieval quality of each of the patterns becomes low. The implications of this trade-off between the number of patterns stored and the retrieval quality of each pattern when graded firing rates are stored for understanding the operation of networks in the hippocampus are considered.     

Inhibition of the activation of Hageman factor (factor XII) by extracts of Schistosoma mansoni.

How intravascular helminth parasites evade host hemostatic defense mechanisms and survive within the circulating blood has not been adequately explained. Previous reports have described an inhibitor of the intrinsic clotting pathway in extracts of adult Schistosoma mansoni. Using a purified preparation of Hageman factor, we examined the ability of schistosome extracts and secretory products to inhibit the activation of human Hageman factor (factor XII) in an amidolytic assay. Both schistosome extracts and secretory products inhibited the activation of purified Hageman factor by more than 95%. Schistosome extracts inhibited activation of Hageman factor both by ellagic acid and by bovine sulfatides. In contrast, activated Hageman factor retained full activity in the presence of schistosome extracts as tested both on an amidolytic synthetic substrate and a natural substrate, plasma thromboplastin antecedent (factor XI). Our findings indicate that extracts and secretory products of adult Schistosoma mansoni contain a potent inhibitor of the activation of Hageman factor. Knowledge of a site at which schistosomes inhibit the intrinsic clotting pathway provides added insight into the mechanisms by which the parasites avoid the host hemostatic defense mechanisms.