Summary
The potential role of wild animals in the maintenance and spread of tuberculosis (TB) infection in domestic livestock is of particular importance in countries where eradication programs have ...substantially reduced the incidence of bovine tuberculosis but sporadic outbreaks still occur. Mycobacterium bovis is the agent mainly isolated in wildlife in Spain, but recently, infections by Mycobacterium caprae have increased substantially. In this study, we have analysed 43 mandibular lymph nodes samples containing TB‐like lesions from 43 hunted wild boar from Madrid and Extremadura (central and south‐western regions of Spain). After isolation, identification and typing of Mycobacterium tuberculosis complex isolates, we found that 23 mandibular lymph nodes involved M. caprae infections and 20 M. bovis. The lesions were compared for histopathology (different granuloma stage and number of multinucleated giant cells (MNGCs)), and acid‐fast bacilli (AFBs) were quantified in the Ziehl‐Neelsen‐stained slides. Granulomas produced by M. caprae showed more stage IV granulomas, more MNGCs and higher AFBs counts than those induced by M. bovis. In conclusion, lesions caused by M. caprae would be more prone to the excretion of bacilli, and infected animals result as a high‐risk source of infection for other animals.
Aims The aim of the study was to assess the incidence and clinical implications of increased plasma angiotensin II despite chronic ACE inhibitor therapy in patients with heart failure. Methods and ...Results The studied population consisted of 70 patients (mean age 59±9 years). Plasma renin activity and plasma concentration of aldosterone, norepinephrine, atrial natriuretic peptide, angiotensin II, tumour necrosis factor, interleukin-6 and interleukin-1B were assessed at 6 months of ACE inhibitor therapy. Mean left ventricular ejection fraction was 24±5% and the end-systolic and end-diastolic diameters were 59±9 and 71±8mm, respectively. Despite chronic enalapril or captopril therapy, 35 patients (50%) had increased plasma angiotensin II (median 33pg.ml−1, range 17–84), while it was in the normal range in the remaining 35 patients (median 10pg.ml−1, range 5–15). Plasma renin activity (P=0·005), interleukin-6 (P=0·004), New York Heart Association functional class III-IV (P=0·006), furosemide dose (P=0·01), lack of beta-blocker therapy (P=0·04) and norepinephrine (P=0·04) were univariately associated with increased angiotensin II. Multivariate regression analysis identified the plasma renin activity (0·0004), norepinephrine (0·02) and interleukin-6 (0·03) as independent predictors of plasma angiotensin II. During follow-up (35±29 months), nine (12·8%) patients died and 13 had new heart failure episodes. Increased plasma angiotensin II, despite ACE inhibitor therapy, was a significant predictor of death or heart failure according to the Kaplan–Meier survival method by log rank test (P=0·002). Conclusion Fifty per cent of patients with heart failure, had increased plasma angiotension II despite chronic ACE inhibitor therapy. These patients had higher neurohormonal activation and poor prognosis.
Limited information has been published on the wild boar immune response against bovine tuberculosis (bTB) and the immunopathogenesis of the pathological hallmark (granuloma) in this species.
The main ...objectives of this study were, on the one hand, to characterize the histopathological features (number of acid-fast bacilli (AFB) and multinucleated giant cells (MNGCs) and the immunohistochemical distribution of different cell subsets (CD3+, CD79a+ and MAC387+) and chemical mediators (iNOS and IFN-γ) in the different developmental stages of granulomas produced by the natural infection of Mycobacterium bovis (M. bovis) in wild boar. On the other hand, the study also aimed to analyze the mechanisms underlying the marked differences in the typical lesional patterns observed in M. bovis infections of wild boar (contained, not generalized) and those previously described in fallow deer (poorly contained, generalized).
The majority of granulomas analyzed (95.3%) did not show any AFB with the ZN stain and a low number of MNGCs were identified in the different granuloma stages. The immunohistochemical analysis showed that MAC387 was the only immune marker that produced decreasing positivity by granuloma stage, being statistically significantly lower in stages III and IV when compared to stage I and II. Immune markers for lymphocyte cells (CD3 and CD79a) showed a slight rise in the positivity (which was not statistically significant) in the advanced granuloma stages. In keeping with the presence of large numbers of T cells and macrophages, there was a consistently high level of expression of IFN-γ at all stages of granuloma development without a statistical significant decrease in advanced stages. Also related with the higher presence of macrophages in stage I and II, the expression of iNOS was higher in early stages and sustained until stage III, showing a non statistical significant decrease in stage IV. The macrophage and iNOS activity are more intense and sustained along the granuloma development than those described in fallow deer.
Immunohistochemical protocols with a panel of markers for wild boar different cells subsets (CD3+, CD79a+ and MAC387+) and chemical mediators (iNOS and IFN-γ), and their use to further investigate the immune response in this species are provided.
Background
The early identification of patients at high risk of severe post liver transplant hepatitis C recurrence is relevant, as these patients may be treated using interferon (IFN)‐free regimens.
...Methods
In a retrospective study with prospectively collected data, we investigated whether the use of several non‐invasive methods (fibrosis 4 index FIB‐4, AST‐to‐platelets ratio index APRI, enhanced liver fibrosis test ELF, IFN‐γ‐inducible protein 10 IP‐10, and transient elastography by Fibroscan) and their combinations 6 months after transplantation could identify those recipients at higher risk of severe recurrence, defined by the presence of significant fibrosis (F ≥2) and/or portal hypertension (hepatic venous pressure gradient ≥6 mmHg) 12 months after transplant. Seventy‐two hepatitis C virus (HCV)‐infected liver transplant patients and 10 recipients in whom HCV was eradicated before transplantation were included in the study.
Results
The levels of all biomarkers were significantly higher in HCV‐infected recipients than in controls. Among HCV recipients, levels of biomarkers were significantly higher in patients with severe recurrence. Although there were no statistically significant differences between biomarkers, APRI, ELF, and FIB‐4 obtained the highest area under the ROC curve values. The combination of serum biomarkers with Fibroscan increased the negative and positive predictive values, although diagnostic accuracy of individual tests was not significantly improved.
Conclusions
Patients at higher risk of severe HCV recurrence can be identified early, 6 months after transplantation, using readily available non‐invasive methods.
Summary
Non‐tuberculous mycobacteria (NTM) are widely distributed in the environment, particularly in wet soil, marshland, rivers or streams, but also are causative agents of a wide variety of ...infections in animals and humans. Little information is available regarding the NTM prevalence in wildlife and their effects or significance in the bovine tuberculosis (bTB) epidemiology and diagnosis. This research shows the most frequently NTM isolated in lymph nodes of wild boar (Sus scrofa) from southern Spain, relating the NTM presence with the individual characteristics, the management of animals and the possible misdiagnosis of Mycobacterium bovis in concurrent infections. A total of 219 NTM isolates were obtained from 1249 wild boar mandibular lymph nodes sampled between 2007 and 2011. All but 75 isolates were identified by the PCR‐restriction analysis‐hsp65, and a partial sequencing of the 16S rDNA was carried out to identify the rest of the isolates. Results showed that Mycobacterium chelonae was the most frequently isolated NTM specie (133 isolates, 60.7%), followed by Mycobacterium avium (24 isolates, 11%). No relation was found regarding sex, body condition and management, but M. chelonae was more frequently detected in adults, whereas M. avium was more prevalent in subadults. The high NTM prevalence observed in the studied wild boar populations could make difficult the bTB diagnostic.
The pathophysiology of circulatory and renal dysfunction in cirrhosis and the treatment of ascites and related conditions (hepatorenal syndrome and spontaneous bacterial peritonitis) have been ...research topics of major interest during the last two decades. However, many aspects of these problem remain unclear and will constitute major areas of investigation in the next millennium. The pathogenesis of sodium retention, the most prevalent renal function abnormality of cirrhosis, is only partially known. In approximately one third of patients with ascites, sodium retention occurs despite normal activity of the renin-aldosterone and sympathetic nervous systems and increased circulating plasma levels of natriuretic peptides and activity of the so-called natriuretic hormone. These patients present an impairment in circulatory function which, although less intense, is similar to that of patients with increased activity of the renin-aldosterone and sympathetic nervous systems, suggesting that antinatriuretic factors more sensitive to changes in circulatory function that these systems may be important in the pathogenesis of sodium retention in cirrhosis. The development of drugs that inhibit the tubular effect of antidiuretic hormone and increase renal water excretion without affecting urine solute excretion has opened a field of great interest for the management of water retention and dilutional hyponatremia in cirrhosis. Two families of drugs, the V2 vasopressin receptor antagonists and the kappa-opioid agonists, have been shown to improve free water clearance and correct dilutional hyponatremia in human and experimental cirrhosis with ascites. The first type of drugs blocks the tubular effect of antidiuretic hormone and the second inhibits antidiuretic hormone secretion by the neurohypophysis. On the other hand, two new treatments have also been proved to reverse hepatorenal syndrome in cirrhosis. The most interesting one is that based on the simultaneous administration of plasma volume expansion and vasoconstrictors. The second is transjugular intrahepatic portosystemic shunt. The long-term administration (1–3 weeks) of analogs of vasopressin (ornipressin or terlipressin) or other vasoconstrictors together with plasma volume expansion with albumin is associated with a dramatic improvement in circulatory function and normalization of serum creatinine concentration in patients with severe hepatorenal syndrome. Of interest is the observation that in many of these patients, hepatorenal syndrome does not recur following discontinuation of the treatment, thus raising important questions about the mechanism by which hepatorenal syndrome follows a progressive course in most untreated cases. The pathogenesis of circulatory dysfunction in cirrhosis and the role of local mechanisms in the development of the splanchnic arteriolar vasodilation associated with portal hypertension will continue as important topics in clinical and basic research in Hepatology. Of special interest is the study of the mechanism by which circulatory function further deteriorates following complications such as severe bacterial infection or therapeutic interventions such as therapeutic paracentesis, and the adverse consequences of the impairment in circulatory function on renal and hepatic hemodynamics. Finally, although major advances have been made concerning the treatment and secondary prophylaxis of spontaneous bacterial peritonitis in cirrhosis, many aspects of the pathogenesis of this infection remain unclear. The mechanism of bacterial translocation and of the colonization of bacteria in the ascitic fluid are particularly important to design adequate measures for primary prophylaxis of this severe bacterial infection.
Research on management of bovine tuberculosis (bTB) in wildlife reservoir hosts is crucial for the implementation of effective disease control measures and the generation of practical bTB management ...recommendations. Among the management methods carried out on wild species to reduce bTB prevalence, the control of population density has been frequently used, with hunting pressure a practical strategy to reduce bTB prevalence. However, despite the number of articles about population density control in different bTB wildlife reservoirs, there is little information regarding the application of such measures on the Eurasian wild boar (Sus scrofa), which is considered the main bTB wildlife reservoir within Mediterranean ecosystems.
This study shows the effects of a management measure leading to a radical decrease in wild boar population density at a large hunting estate in Central Spain, in order to assess the evolution of bTB prevalence in both the wild boar population and the sympatric fallow deer population.
The evolution of bTB prevalence was monitored in populations of the two wild ungulate species over a 5-year study period (2007–2012). The results showed that bTB prevalence decreased in fallow deer, corresponding to an important reduction in the wild boar population. However, this decrease was not homogeneous: in the last season of study there was an increase in bTB-infected male animals. Moreover, bTB prevalence remained high in the remnant wild boar population.
Mycobacterium bovis infections in fallow deer have been reported in different countries and play an important role in the epidemiology of bovine tuberculosis (bTB), together with other deer species. ...There is little knowledge of the pathogenesis of bTB in fallow deer. The aim of this study was to perform a histopathological characterisation of the granulomas induced by M. bovis in this species and the immunohistochemical distribution of different cell subsets (CD3+, CD79+, macrophages) and chemical mediators (iNOS, TNF-α, IFN-γ) in the different developmental stages of granulomas. Stage I/II granulomas showed a marked presence of macrophages (MAC387+) expressing high iNOS levels while stage III/IV granulomas showed a decrease in the number of these cells forming a rim surrounding the necrotic foci. This was correlated with the presence of IFN-γ expressing cell counts, much higher in stage I/II than in stage III/IV. The number of B cells increased alongside the developmental stage of the granuloma, and interestingly the expression of TNF-α was very low in all the stages. This characterisation of the lesions and the local immune response may be helpful as basic knowledge in the attempts to increase the vaccine efficacy as well as for disease severity evaluation and for the development of improved diagnostic tools. Immunohistochemical methods using several commercial antibodies in fallow deer tissues are described.
PDF
