Risedronate in the treatment of Murine Chagas’ disease

Risedronate, a bisphosphonate, was used to treat CD-1 mice infected with the Brazil strain of Trypanosoma cruzi. When given by subcutaneous injection 3 times/week, there was a significant reduction in mortality, however, the myocardial pathology and right ventricular dilation was unchanged in these mice compared to control animals. In C57BL/6 mice infected with the Tulahuen strain, there was no change in mortality in response to risedronate treatment. These data suggest that this class of compounds has activity against T. cruzi in vivo and illustrate the utility of imaging and pathologic studies as adjuncts in the evaluation of therapeutic compounds as treatments for experimental Chagas disease. In addition, it underscores the need to use different strains of T. cruzi.     

Expression of cytokines and chemokines and microvasculature alterations of the tongue from patients with chronic Chagas’ disease

Chagas’ disease is caused by the protozoan Trypanosoma cruzi and continues to be a significant public health problem, since 10 million people are still infected in Latin America. The purpose of this study was to analyze the microvasculature alterations as well the expression of cytokines and chemokines in the tongues from patients with chronic Chagas’ disease (CC; n = 18), comparatively with a non-chagasic group (NC; n = 22). We observed several vascular alterations in the tongue of CC such as a greater vascular diameter, increased vascular wall area, high density of the blood vessels, and increased thickening of the capillary basement membrane. The expression of cytokines interferon gamma and tumor necrosis factor alpha and chemokine macrophage inflammatory protein 1α were significantly down-regulated in the tongue of CC group. These results demonstrated that, in the tongue of chagasic patients, a microvascular abnormality and immunological impairment occurs, probably due to chronic inflammation evoked by T. cruzi antigens.     

Allelic exclusion of immunoglobulin gene rearrangement and expression: why and how?

Since the discovery of the allelic exclusion of immunoglobulin (Ig) gene expression by Pervis in the 1960s [J. Exp. Med. 122 (1965) 853], much attention has been focused on its mechanism. Much less attention has been paid, however, to the question of why B cells demonstrate such unusual genetic regulation of antigen receptor gene expression. A large body of literature implicates the Ig gene products as feedback regulators of their own genetic rearrangement [Adv. Immunol.78 (2001)169; Science 236 (1987)816]. While a role for Ig gene products in the regulation of V(D)J recombination is beyond debate, it is extremely unlikely that such a feedback mechanism would be fast enough to avoid occasional near-simultaneous rearrangement of allelic loci leading to dual receptor gene expression. This review will suggest an hypothesis to answer the 'why bother' aspect of allelic exclusion and then go on to propose a mechanism, distinct from feedback regulation, which may contribute to the allelic exclusion of Ig gene expression.     

Vitamin D and the development of allergic disease: how important is it?

Vitamin D has known effects on lung development and the immune system that may be important in the development, severity, and course of allergic diseases (asthma, eczema, and food allergy). Vitamin D deficiency is prevalent worldwide and may partly explain the increases in asthma and allergic diseases that have occurred over the last 50–60 years. In this review, we explore past and current knowledge on the effect of vitamin D on lung development and immunomodulation and present the evidence of its role in allergic conditions. While there is growing observational and experimental evidence for the role of vitamin D, well‐designed and well‐powered clinical trials are needed to determine whether supplementation of vitamin D should be recommended in these disorders.     

Cerebral small vessel disease and the risk of Alzheimer’s disease: A systematic review

BackgroundCerebral small vessel disease (CSVD) comprises a variety of disorders affecting small arteries and microvessels of the brain, manifesting as white matter hyperintensities (WMHs), cerebral microbleeds (CMBs), and deep brain infarcts. In addition to its contribution to vascular dementia (VaD), it has also been suggested to contribute to the pathogenesis of Alzheimer’s disease (AD).MethodA systematic review of the literature available on Medline, Embase and Pubmed was undertaken, whereby CSVD was divided into WMHs, CMBs and deep brain infarcts. Biomarkers of AD pathology in the cerebrospinal fluid or plasma, or positron emission tomographic imaging for amyloid and/or tau deposition were used for AD pathology.ResultsA total of 4117 articles were identified and 41 articles met criteria for inclusion. These consisted of 17 articles on vascular risk factors for clinical AD, 21 articles on Aβ pathology and 15 articles on tau pathology, permitting ten meta-analyses. CMBs or lobar CMBs were associated with pooled relative risk (RR) of AD at 1.546, (95%CI 0.842–2.838, z = 1.41 p = 0.160) and 1.526(95%CI 0.760–3.063, z = 1.19, p = 0.235) respectively, both non-significant. Microinfarcts were associated with significantly increased AD risk, with pooled odds ratio OR at 1.203(95%CI 1.014–1.428, 2.12 p = 0.034). Aβ pathology was significantly associated with WMHs in AD patients but not in normal age-matched controls. The pooled β (linear regression) for total WMHs with CSF Aβ42 in AD patients was -0.19(95%CI -0.26–0.11, z = 4.83 p = 0.000) and the pooled r (correlation coefficient) for WMHs and PiB in the normal population was -0.10 (95%CI -0.11–0.30, 0.93 p = 0.351). CMBs were significantly associated with Aβ pathology in AD patients. The pooled standardized mean difference (SMD) was -0.453, 95%CI -0.697– -0.208, z = 3.63 p = 0.000. There was no significant relationship between the incidence of lacunes and levels of CSFAβ, with a pooled β of 0.057 (95%CI -0.050–0.163, z = 1.05 p = 0.295). No significant relationship was found between CMBs and the levels of CSFt-tau/CSFp-tau in AD patients (-0.014, 95%CI -0.556–0.529, z = 0.05 p = 0.960; -0.058, 95%CI -0.630–0.515, z = 0.20 p = 0.844) and cortical CMBs and CSF p-tau in the normal population (0.000, 95%CI -0.706–0.706, z = 0.00 p = 0.999).ConclusionsSome CSVD markers were significantly associated with clinical AD pathology and may be associated with Aβ/tau pathology. WMHs and microinfarcts were associated with increased risk of AD. It remains unclear whether they precede or follow AD pathology.     

Microbeads and flow cytometry: how and why put the "-metry" in immuno-cytometry?

In current practice of immunophenotyping, flow cytometers are mainly used as cell counters. These instruments which measure fluorescence intensity on each individual cell with high sensitivity can also count molecules on cells. "Putting the - metry into cytofluorometry" means measuring the expression level of molecules of biological interest on (in) target cells. Candidate molecules are numerous due to the many membrane receptors which biological function depends on the number of accessible molecules. Any modulation of the expression level brings valuable information to the biologist, beit associated to physiological differentiation, pathological state or therapeutic intervention. In order to take the best from such measurements in clinical biology, full reliability is mandatory in terms of time-to-time, platform-to-platform and lab- to-lab reproducibility. One should ban "arbitrary units" as currently provided by the instruments to switch to real units. This paper tends to review the most important features conditioning a reliable quantitation of cellular antigens, with data expressed in terms of number of molecules per cell. In addition to staining tools (antibody-based reagents) and data treatment softwares, calibration tools are mandatory. They are not all equivalent. Fluorescent beads with internal fluorescence are very useful for instrument quality-control but they can not interchange with immunological calibration systems which measure the number of antibody molecules that can bind onto the cells. Numerous application examples illustrate the interest of this "quantitative" dimension of Immunocytometry. Generalization of this approach would help getting a wider access to clinical biology.     

Celiac disease and immunoglobulin a deficiency: how effective are the serological methods of diagnosis?

Immunoglobulin A (IgA) deficiency is 10 to 15 times more common in patients with celiac disease (CD) than in healthy subjects. Serological tests have become the preferred methods of diagnosing CD in both symptomatic and asymptomatic patients. However, commercially available serological methods are limited in that they detect only the IgA isotype of antibodies (with the exception of IgG gliadin assays); hence, IgA-deficient patients with CD may yield false-negative serology. Fifteen pediatric patients with CD and 10 IgA-deficient pediatric patients without CD were examined for IgA and IgG antibodies to endomysium, gliadin, and tissue transglutaminase. Twenty-five specimens from patients with IgA deficiency were examined. Fifteen were from patients with CD, and 10 were patients without CD. All 15 IgA-deficient patients with CD were positive for endomysium antibodies of the IgG isotype and for IgG gliadin antibodies. All but one of the IgA-deficient patients with CD were also positive for IgG tissue transglutaminase antibodies. None of the IgA-deficient patients without CD were positive for any of the antibody markers. All the specimens examined were also negative for IgA-specific antibodies to endomysium, gliadin, and tissue transglutaminase. IgG-specific antibody tests for endomysium, gliadin, and tissue transglutaminase are useful for the identification of IgA-deficient patients with CD. IgG antibody tests along with tests routinely being used in clinical laboratories can reliably detect all active patients with CD. In addition, the levels of these CD-specific IgG antibodies could be used to monitor patient dietary compliance.     

In vivo EPR: when, how and why?

This special issue is aimed at providing the readers of this journal with an indication of the exciting and important areas in which in vivo electron paramagnetic resonance (EPR) [or equivalently electron spin resonance (ESR)] is making contributions to experimental progress and to provide perspectives on future developments, including the potential for in vivo EPR to be an important new clinical tool. There also are many situations where the combination of in vivo EPR with NMR may be very synergistic. EPR (ESR) is a magnetic resonance-based technique that detects species with unpaired electrons. The technique has become a major tool in diverse fields ranging from biology and chemistry to solid-state physics. In the last few years, many publications have demonstrated that EPR measurements in living animals (in vivo EPR) can provide very significant new insights to physiology, pathophysiology and pharmacology. The most successful applications of in vivo EPR have been non-invasive measurements of oxygen, nitric oxide, bioradicals, pH and redox state, with applications in oncology, cardiology, neuroscience and toxicology. EPR also appears to be the method of choice for measuring radiation dose retrospectively, including the potential to do this in vivo in human subjects. While far from comprehensive, the reviews, original contributions and viewpoints provided in this issue by several leaders in the field of in vivo EPR should provide the readers with confirmation that in vivo EPR is an exciting field that is likely to provide very valuable complementary information for many NMR-based studies in experimental animals and, probably, also for clinical studies.     

Protection of vascular endothelium by aspirin in a murine model of chronic Chagas’ disease

Chronic Chagas’ disease affects 10–30 % of patients infected with Trypanosoma cruzi, and it mainly manifests as cardiomyopathy. Important pathophysiological mechanisms involved in the cardiac lesions include activation of the endothelium and induced microvascular alterations. These processes involve the production of endothelial adhesion molecules and thromboxane A₂, which are involved in inflammatory cell recruitment and platelet aggregation, respectively. Cyclooxygenase inhibitors such as aspirin decrease thromboxane production and alter the course of Chagas’ disease, both in the acute and chronic phases. We studied the effects of the administration of low and high doses of aspirin during the early phase of T. cruzi infection, following microvascular damage in the context of a chronic murine model of Chagas’ disease. The effects of both schedules were assessed at 24 and 90 days postinfection by evaluating parasitemia, mortality, and cardiac histopathological changes as well as the expression of ICAM, VCAM, and E-selectin in cardiac tissue. Thromboxane A₂, soluble ICAM, and E-selectin blood levels were also measured. While aspirin did not affect parasitemia or mortality in the infected mice, it decreased both cardiac inflammatory infiltrates and thromboxane levels. Additionally, at 90 days postinfection, aspirin normalized sICAM and sE-selectin levels. Considering the improved endothelial function induced by aspirin, we propose the possibility of including this drug in clinical therapy to treat chronic Chagas’ disease.     

Chemotherapy in alveolar echinococcosis of multi-organs: what’s the role?

The aim of this study was to investigate the clinical efficiency of chemotherapy for the treatment of human alveolar echinococcosis (AE). Twenty-four patients who suffered from late-stage AE were enrolled in this study. The classification of the disease stages was performed according to the PNM (parasite lesion, neighboring organ invasion, metastases) classification system established by the World Health Organization Informal Working Group on Echinococcosis and classification standards. Radical surgery (n?=?3), palliative surgery plus chemotherapy (n?=?11), and sole chemotherapy (n?=?10) were given, respectively. For those with AE metastasis with spleen and kidney, radical surgery was effective for the treatment. However, the treatment efficiency for those with AE metastasis to bone tissues was unfavorable. Significant improvement was noted in those with cerebral lesions after chemotherapy. Stable health conditions were observed in those with pulmonary lesions after chemotherapy. For those with liver lesion, long stable health conditions were noted after chemotherapy. However, surgical interventions were needed as the occurrence of bile duct complications. With regards to the other lesions, radical surgeries were recommended. Satisfactory treatment outcomes were obtained in those with AE after chemotherapy.     

Cortisol hypersecretion and the risk of Alzheimer’s disease: A systematic review and meta-analysis

BackgroundMorning cortisol levels have been reported to be elevated among patients with Alzheimer’s disease (AD); yet no meta-analysis has been conducted to confirm the existence and magnitude of this association. It also remains unclear whether hypercortisolism is a risk factor for AD.MethodsPubMed, EMBASE, and PsycINFO were systematically searched for eligible studies. Cross-sectional data were pooled using random-effects meta-analyses; the differences in morning cortisol levels between patients and cognitively normal controls were quantified. Longitudinal studies were qualitatively synthesised due to methodological heterogeneity.Results17,245 participants from 57 cross-sectional studies and 19 prospective cohort studies were included. Compared with cognitively normal controls, AD patients had moderately increased morning cortisol in blood (g = 0.422, P < 0.001; I² = 48.5 %), saliva (g = 0.540, P < 0.001; I² = 13.6 %), and cerebrospinal fluids (g = 0.565, P = 0.003; I² = 75.3 %). A moderate elevation of morning cortisol was also detected in cerebrospinal fluids from patients with mild cognitive impairment (MCI) versus controls (g = 0.309, P = 0.001; I² = 0.0 %). Cohort studies suggested that higher morning cortisol may accelerate cognitive decline in MCI or mild AD patients, but the results in cognitively healthy adults were inconsistent.ConclusionsMorning cortisol was confirmed to be moderately elevated in AD patients and may have diagnostic and prognostic values for AD.     

Comparative karyotype using bidirectional chromosome painting: how and why?

Rat is widely used in biomedical and pharmaceutical research but its genome has been significantly less studied than that of the mouse. This represents a major limitation for studying cytogenetic and molecular mechanisms in the rat model. As Muridae species underwent an intense chromosome evolution it is not possible to directly transpose knowledge of the mouse genome to that of the rat. For establishing a comparative karyotype between rat and mouse, painting probes of both species were prepared by PARM-PCR (Priming Authorizing Random Mismatches PCR) from a low copy number of sorted chromosomes, the mouse and rat specific painting probes being then hybridized on rat and mouse metaphases, respectively. The availability of rodent species chromosome painting probes as well as the information obtained by the comparative karyotype and comparative gene mapping data are of great interest to improve knowledge on species evolution but also to better understand carcinogenesis process, as illustrated by our data concerning the cytogenetic characterization of radon-induced rat lung tumors. Detailed methods for obtaining painting probes by PARM-PCR from sorted mouse and rat chromosomes and for their hybridization in homologous or heterologous conditions are described. Usefulness of chromosome painting is illustrated by the characterization of chromosomal abnormalities in a radon-induced rat lung tumor. Advantages and limitations of this technique as compared to classical cytogenetics, FISH and CGH are discussed.     

Crohn’s disease of the appendix

Although appendectomy is often the first surgical procedure in patients with Crohn's disease (CD), only few data exist on appendiceal CD. The aim of this study was to analyze appendices of CD patients undergoing surgery. We analyzed 149 specimens from consecutive patients with CD who underwent primary right ileocolonic or (sub)total colonic resection. The appendix was present in 90 resection specimens. Histologic findings were compared with those of 180 age and sex matched controls. Thirty-six appendices showed histologic signs of CD (40%): A transmural inflammation was found in 24 cases (67%), and a mucosal inflammation in 12 cases (33%). Histologic hallmarks of mucosal involvement were focal or discontinuous inflammation with crypt distortion and a histiocytic and lymphocytic predominant inflammation. Furthermore, epitheloid granulomas and erosions or ulcers with abundant histiocytes at the lesions base were observed. In comparison to controls luminal obliteration was significantly overrepresented in CD whereas acute phlegmonous appendicitis was underrepresented ( P<0.01). Patients with CD of the appendix showed a more widespread colonic involvement than those without ( P<0.01). This study shows that CD of the appendix exhibits specific histologic features that allow a differentiation from non-CD-associated appendicitis. CD-associated appendicitis is a frequent event, probably signifying a more widespread colonic involvement.     

Metabolic syndrome: what, why, how and who?

Although first knowledge on the joint onset of cardiovascular risk factors had been gained earlier, the first systematic review of this condition was made by G. Reaven in 1988 with his thesis on syndrome X, today known as the metabolic syndrome, with insulin resistance as the common denominator. Four elements have been identified: central obesity, dyslipoproteinemia (increased triglycerides, reduced HDL cholesterol), hypertension and glucose intolerance. There are two most influential definitions: one by the National Cholesterol Education Program (NCEP) and the other by the International Diabetes Federation (/IDF). NCEP requires the presence of at least three of the following factors: abdominal obesity as assessed by waist circumference >102 cm (m) or >88 cm (f), dyslipoproteinemia defined as triglyceridemia > or =1.7 mmol/L and/or HDL cholesterol <1.03 mmol/L (m); <1.29 mmol/L (f), hypertension (blood pressure > or =30/85 mmHg) and fasting glycemia > or =5.6 mmol/L (previously 6.1). IDF focuses on central obesity defined as waist circumference, taking into consideration sex and ethnic group specificities, with the presence of at least two additional factors (dyslipoproteinemia, hypertension, or increased fasting glycemia - all criteria virtually the same as in NCEP definition). Both IDF and NCEP define abdominal obesity by waist circumference, taking account of sex differences, and, in case of IDF, ethnic ones as well. The idea is to identify the simplest measure to indirectly determine the accumulation of visceral fat, which is, contrary to subcutaneous fat, a significant cardiovascular risk factor. However, waist circumference as the only criterion seems to be less specific than the waist-to-hip circumference ratio, which defines the risk more specifically and also better reflects insulin resistance. There is broad discussion as to whether the term metabolic syndrome contributes to the identification of persons at risk of cardiovascular disease better than its components, and, if so, which is the right set of components. It is being recommended that the discussion on the metabolic syndrome be limited to persons without diabetes or already diagnosed cardiovascular disease, as the primary goal for these individuals is to prevent these diseases. It has already been shown that this was possible, primarily by intensive change in lifestyle - healthy diet and exercise. In conclusion, further basic research is necessary to explain the pathophysiologic mechanisms, which might serve to develop new therapies. Moreover, epidemiological and public health aspects are extremely important in the creation of a prevention program. Preliminary results of the Croatian Health Survey (2003) indicate that the metabolic syndrome according to the IDF criteria is present even in the youngest age group, with expected age-dependent increase in both men and women. This is even an underestimate since in this survey only blood pressure and waist circumference were actually measured, and data on dislipidemia and blood glucose were based on a questionnaire. It is already obvious that a wide action with two main goals aimed primarily at the youngest population is necessary: an increase in regular physical activity and the promotion of healthy and energy-adequate diet in the population at large.     

alpha-Synuclein and intracellular trafficking: impact on the spreading of Parkinson’s disease pathology

Parkinson’s disease is characterized by intracellular proteinaceous depositions known as Lewy bodies. These largely consist of the protein α-synuclein, whose physiological function remains unclear, but mutations and overexpression of the protein have been shown to cause early onset cases of Parkinson’s disease. Deregulation of α-synuclein biology causes neurodegeneration and impaired neuronal trafficking, hinting at a possible contribution to the pathological mechanism. Recent studies produced some evidence hinting at the involvement of several regulators of the transport machinery such as Rab GTPases and SNARE proteins, but also shown that α-synuclein can be propagated between cells. Here, we discuss the molecular interplay of α-synuclein with the intracellular transport machinery, its consequences, and the implications for disease mechanisms.