Recognizing and treating myocarditis in recent-onset systemic sclerosis heart disease: Potential utility of immunosuppressive therapy in cardiac damage progression

Objectives

Scleroderma heart disease is a major risk of death in systemic sclerosis (SSc). Mechanisms underlying myocardial damage are still unclear. We performed an extensive study of SSc patients with recent-onset symptoms for heart disease and examined the efficacy of immunosuppressive therapy.

Methods

A cohort of 181 SSc patients was enrolled. Of these, 7 patients newly developed clinical symptoms of heart disease (heart failure, chest pain, and palpitation); all of them showed mild but persistent increase in cardiac enzymes. These patients underwent Holter ECG, 2D-echocardiography, perfusional scintigraphy, delayed-enhancement-cardiac magnetic resonance (DE-CMR), coronary angiography, and endomyocardial biopsy. Patients were treated for at least 12 months and followed-up for 5 years.

Results

Ventricular ectopic beats (VEBs) were found in 4 patients, wall motion abnormalities in 3, pericardial effusion in 6, and DE in CMR in 6 with T2-hyperintensity in 2. In all patients, histology showed upregulation of endothelium adhesion molecules and infiltration of activated T lymphocytes, with (acute/active myocarditis in 6) or without (chronic/borderline myocarditis in 1) myocyte necrosis. Parvovirus B19 genome was detected in 3. None showed occlusion of coronary arteries or microvessels. Compared with SSc controls, these patients more often had early disease, skeletal myositis, c-ANCA/anti-PR3 positivity, VEBs, pericardial effusion, and systolic and/or diastolic dysfunction. Immunosuppressive therapy improved symptoms and led to cardiac enzyme negativization; however, 2 patients died of sudden death during follow-up.

Conclusions

Myocarditis is a common finding in SSc patients with recent-onset cardiac involvement. Its early detection allowed to timely start an immunosuppressive treatment, preventing cardiac damage progression in most cases.     

Influence of Mansonella perstans microfilaraemia on total IgE levels in Gabonese patients co-infected with Loa loa

Mansonella (M.) perstans filariasis is widely found in Africa, including Gabon where Loa loa is also endemic. This study reports the total IgE titres according to different bioclinical forms of single or co-infection with L. loa and M. perstans in 138 patients and 20 healthy controls. The median parasite density was significantly higher in cases of loiasis. IgE titres were higher in patients with microscopic dual-infection and in the group of patients with occult loiasis plus M. perstans microfilaraemia (8425 [5292–20,679] KUI/L and 6304 [1045–10,326] KUI/L, respectively), compared to individuals with either microfilaraemic Loa loa (3368 [1414–7074] KUI/L) or Mansonella (4370 [1478–7334] KUI/L) single infections (p < 0.01). IgE levels were positively correlated with M. perstans microfilaraemia (rho = 0.27; p < 0.01). Compared to single infections, dual M. perstans–L. loa infection induces very high total IgE titres. Studies correlating IgE titres and clinical symptoms are needed to confirm the involvement of this immunoglobulin in the pathological processes during filariasis.     

From morbidity control to transmission control: time to change tactics against helminths on Unguja Island,Zanzibar

In Zanzibar, the prevalence and intensity of helminth infections have markedly declined over the past 25 years, which is generally attributed to morbidity control programmes emphasising ‘preventive chemotherapy’. Here we provide an update of the current situation of soil-transmitted helminthiasis and urinary schistosomiasis on Unguja Island, and highlight socioeconomic development, improvement in sanitation and health education as additional drivers against helminthiases. Our data were obtained from cross-sectional surveys carried out between 2006 and 2009 with stool and urine samples from 2858 and 879 individuals, respectively, examined for helminth eggs and larvae. Additionally, several hundred people were interviewed on sanitation and hygienic behaviour. Data on Unguja's economic growth and improvements in access to clean water and household latrines in the recent past were derived from the extant literature. Pooled prevalences of Trichuris trichiura, Schistosoma haematobium, Ascaris lumbricoides, hookworm and Strongyloides stercoralis were 35%, 29%, 12%, 10% and 6%, respectively. However, there were considerable differences in prevalences between different age-groups and at village and district level. Moreover, some hotspots for A. lumbricoides, T. trichiura and S. haematobium were identified with prevalences above 60% among school-aged children. Availability of a latrine and washing hands before eating did not significantly lower the risk of helminth infections in our study population. Nevertheless, a considerable increase in access to household latrines (from 49% to 72%) and piped water (from 45% to 71%) between 1991 and 2005 is likely to have contributed to reducing the force of transmission of helminthiases in Zanzibar. The next logical step in Unguja is to change the tactics from morbidity control to interruption of helminth transmission and ultimately local elimination. Hence, ‘preventive chemotherapy’ needs to be further consolidated, placing particular emphasis on health education and improved access to clean water and sanitation.     

Proteome analysis of the cardiac and pericardial tissue of Biomphalaria tenagophila populations susceptible and resistant to Schistosoma mansoni infection

For a better comprehension of the parasite-host interaction, proteins expressed by the cardiac and pericardial tissues were compared between susceptible (Cabo Frio) and resistant (Taim) Biomphalaria tenagophila populations, challenged (c) and non-challenged (nc) with Schistosoma mansoni. Proteins were separated by two-dimensional gel electrophoresis (2DE) and stained with Coomassie blue. A total of 146 and 135 spots were observed in Cabo Frio (CFnc) and in Taim (Tnc) non-challenged populations, respectively, whereas 153 spots were detected in both Cabo Frio (CFc) and Taim (Tc) challenged populations. Regarding comparisons between CFnc and CFc, the numbers of exclusive spots obtained were one and nine, respectively, whereas Tnc yielded 17 and Tc eight exclusive spots. By comparing the total of spots in CF (nc+c) with T (nc+c) populations, we obtained: four exclusive spots for CFc; zero for CFnc; four for Tc and; one for Tnc. A quantitative comparison (reason>2.5) of the total spots of CF (nc+c) with T (nc+c) populations allowed us to distinguish five more intense spots for Tc, 14 for Tnc, 15 for CFnc and 11 for CFc. In the CFnc population, two proteins were identified: actin and ATP synthase alpha chain; in the CFc population, four proteins: actin, calmodulin, HSP70, and dehydrogenase; in the Tnc population, five proteins: matrilin, HSP70, actin, ATP synthase alpha chain and intermediate filament of the protein; and in the Tc population, three proteins: actin, alpha-S1 casein and ATP synthase alpha chain. Out of a total of 79 spots, only nine proteins were identified due to the low number of available nucleotide sequences in the GenBank. Nevertheless, knowing proteins regarded as differentially expressed is indispensable for hitherto unidentified genes implicated in B. tenagophila resistance and or susceptibility to S. mansoni infection.     

Changed gene expression for candidate ageing genes in long-lived Bicyclus anynana butterflies

Candidate genes for the regulation of lifespan have emerged from studies that use mutants and genetically manipulated model organisms. However, it is rarely addressed whether these genes contribute to lifespan variation in populations of these species that capture natural standing genetic variation. Here, we explore expression variation in three candidate ageing genes, Indy, sod2, and catalase, in Bicyclus anynana, a butterfly with well understood ecology.We used lines established from natural populations and artificially selected for increased adult starvation resistance. They show a considerable increase in adult lifespan under both starvation and optimal food conditions. We measured adult butterflies of various ages, under a range of optimal and starvation diets, from two selected populations and one unselected control population.In all lines, Indy and catalase are up-regulated in response to starvation while this is not evident for sod2. Under starvation, Indy and catalase are up-regulated in, while this is not evident for sod2. Under optimal food conditions, Indy is down-regulated at a later age, with Indy expression showing relatively high inter-individual variation. We find differences between the selected lines and the unselected line. Under starvation conditions, expression is higher for catalase in one, and for sod2 in both selected lines. Importantly, sod2 expression is also higher in the selected populations under optimal food conditions.We conclude that sod2, but not Indy, is involved in the response to artificial selection for increased starvation resistance. The role of catalase is less clear because of the differences between the two selected lines. Moreover, sod2 appears to be a candidate gene that underpins the genetic correlation between starvation resistance and longevity. Our study indicates that some, but not all, genes identified through mutant screens in other organisms may underpin standing genetic variation for ageing-related traits in stocks of Bicyclus butterflies established from natural populations. Clearly, this needs to be investigated in other organisms as well, especially in the organisms to which mutants screens were applied. This information will narrow down the list of genes that underpin variation in lifespan and ageing in extant populations of organisms, and which may serve as candidate genes in humans.     

The origins and spread of antimalarial drug resistance: lessons for policy makers

Understanding the frequency with which new resistance alleles arise and their subsequent patterns of spread is critical to our attempts to manage drug resistance in parasite populations. We review recent molecular evolutionary studies utilizing marker loci situated close to resistance loci on the Plasmodium falciparum genome that have given surprising insights into the origins and spread of drug resistance loci. We discuss possible reasons for the patterns observed, and highlight the implications of these results for resistance management. In particular, we show that many resistance mutations have rather few independent origins. De novo mutation appears to be less important than migration for introducing resistance alleles into parasite populations. Attempts to manage drug resistance will be of limited effectiveness unless this is taken into account.     

Plasmodium falciparum GPI toxin: A common foe for man and mosquito

The glycosylphosphatidylinositol (GPI) anchor of the malaria parasite, Plasmodium falciparum, which can be regarded as an endotoxin, plays a role in the induced pathology associated with severe malaria in humans. However, it is unclear whether the main mosquito vector, Anopheles gambiae, can specifically recognize, and respond to GPI from the malaria parasite. Recent data suggests that the malaria vector does mount a specific response against malaria GPI. In addition, following the strong immune response, mosquito fecundity is severely affected, resulting in a significant reduction in viable eggs produced. In this mini-review we look at the increased interest in understanding the way that malaria antigens are recognized in the mosquito, and how this relates to a better understanding of the interactions between the malaria parasite and both human and vector.     

Usefulness of rickettsial PCR assays for the molecular diagnosis of human rickettsioses

Background

The effectiveness of PCR methods to amplify rickettsiae from clinical samples has still not been evaluated. Our aim was to determine the sensitivity and usefulness for Rickettsia species identification by PCR methods, targeting 16S rDNA, htrA, gltA, ompA, and ompB genes for molecular diagnosis of rickettsioses.

Methods

A total of 72 clinical samples (EDTA-blood, skin biopsies and ticks) taken from 52 patients in the early phase of the illness with PCR-confirmed rickettsioses were included. Single [16S rDNA, gltA (5′ end), and htrA genes] and sequential (nested or semi-nested) PCR assays [ompB, gltA (central region) and ompA genes] were performed.

Results

For single-stage PCR assays, the greatest sensitivity (33.3%) was obtained using the gltA (5′ end), while for sequential assays, the most sensitive results were obtained using the ompB assay (83.3%). The highest sensitivity (100%) was achieved using the three sequential PCRs. The ompA PCR method was the most reliable for identifying Rickettsia species, according to clinical features.

Conclusions

PCR-based amplification methods are useful rickettsial diagnostic tools in the early phase of the illness. The three sequential PCR assays here investigated (ompB, gltA and ompA) appear to be useful tools for molecular diagnosis of rickettsioses. ompB PCR assay is effective for primary screening, since it detects a high percentage of positive samples. ompA assay is the most useful method to identify a Rickettsia species in human pathology. Nevertheless, epidemiology, clinical symptoms and the vector involved in the infection have to be taken into account for the diagnosis of rickettsioses.     

Species-specific loop-mediated isothermal amplification (LAMP) for diagnosis of trypanosomosis

In this study, we developed loop-mediated isothermal amplification (LAMP) for the specific detection of both animal and human trypanosomosis using primer sets that are designed from 5.8S rRNA-internal transcribed spacer 2 (ITS2) gene for Trypanosoma brucei gambiense, 18S rRNA for both T. congolense and T. cruzi, and VSG RoTat 1.2 for T. evansi. These LAMP primer sets are highly sensitive and are capable of detecting down to 1 fg trypanosomal DNA, which is equivalent to approximately 0.01 trypanosomes. LAMP is a rapid and simple technique since it can be carried out in 1 h and requires only a simple heating device for incubation. Therefore, LAMP has great potential of being used for diagnosis of trypanosomosis in the laboratory and the field, especially in countries that lack sufficient resources needed for application of molecular diagnostic techniques.     

Time to set the agenda for schistosomiasis elimination

It is time to raise global awareness to the possibility of schistosomiasis elimination and to support endemic countries in their quest to determine the most appropriate approaches to eliminate this persistent and debilitating disease. The main interventions for schistosomiasis control are reviewed, including preventive chemotherapy using praziquantel, snail control, sanitation, safe water supplies, and behaviour change strategies supported by information, education and communication (IEC) materials. Differences in the biology and transmission of the three main Schistosoma species (i.e. Schistosoma haematobium, S. mansoni and S. japonicum), which impact on control interventions, are considered. Sensitive diagnostic procedures to ensure adequate surveillance in areas attaining low endemicity are required. The importance of capacity building is highlighted. To achieve elimination, an intersectoral approach is necessary, with advocacy and action from local communities and the health community to foster cooperative ventures with engineers, the private sector, governments and non-governmental organizations specialized in water supply and sanitation. Examples of successful schistosomiasis control programmes are reviewed to highlight what has been learnt in terms of strategy for control and elimination. These include St. Lucia and other Caribbean islands, Brazil and Venezuela for S. mansoni; Saudi Arabia and Egypt for both S. mansoni and S. haematobium; Morocco, Tunisia, Algeria, Mauritius and the Islamic Republic of Iran for S. haematobium; Japan and the People's Republic of China for S. japonicum. Additional targets for elimination or even eradication could be the two minor human schistosome species S. guineenisis and S. intercalatum, which have a restricted distribution in West and Central Africa. The examples show that elimination of schistosomiasis is an achievable and desirable goal requiring full integration of preventive chemotherapy with the tools of transmission control. An agenda for the elimination of schistosomiasis would aim to identify the gaps in knowledge, and define the tools, strategies and guidelines that will help national control programmes move towards elimination, including an internationally accepted mechanism that allows verification/confirmation of elimination.     

Regional Network for Research,Surveillance and Control of Asian Schistosomiasis (RNAS)

In order to strengthen the communication, cooperation and coordination among scientists and control authorities concerned with these parasitic diseases at the regional level, the establishment of the Regional Network on Asian Schistosomiasis (RNAS) was initiated 1998 in Wuxi, People's Republic of China. The RNAS was facilitated by an initiating collaborative research grant from WHO/TDR in 1999. The main activities and achievements of the RNAS during its first 2 years of existence are described. It is hoped that more interested parties will become involved in the network activities and other international agencies will consider providing technical and financial support to the network in the future to ensure the sustained development of the RNAS. The website of RNAS is now available in both English and Chinese versions with URL address: http://www.rnas.org. Thus far, the RNAS has held two important meetings with a third planned for 2002. The annual meeting will involve scientists and control authorities from all countries endemic for Asian schistosomiasis, providing a forum for more regional cooperation and coordination. More focus will be directed at training activities in specific fields such as immunodiagnostics, standardization of ultrasound use for monitoring infection-related morbidity, cost factor analysis, application of GIS/RS technology, environmental modification and human behaviour, agricultural efforts including livestock management for control of schistosome transmission, etc.     

Prevention of Plasmodium vivax malaria recurrence: Efficacy of the standard total dose of primaquine administered over 3 days

Background

The standard total dose (STD) of primaquine to prevent Plasmodium vivax recurrence is 0.25 mg/kg day administered over 14 days (STD-14). We evaluated, in an endemic zone of Colombia, the anti-recurrence efficacy of the STD dose administered over 3 and 14 days, and of sub-STD dose administered over 3 days (71%STD-3, 50%STD-3).

Methods

A controlled clinical trial was carried out with 188 subjects allocated into one of four treatment groups: STD-14, STD-3, 71%STD-3, 50%STD-3.

Results

Recurrences during the 120 days of follow-up were 15% in STD-14, and 57% in STD-3. Treatment with 71%STD-3 and 50%STD-3 resulted in recurrence in >48% subjects within 120 days after the primary episode. High daily doses (1.17 mg/kg day) were well tolerated.

Conclusions

(a) The standard dose and regimen (STD-14) of primaquine to prevent P. vivax relapse is recommended. The administration of the same dose over 3 days (STD-3) should be avoided; (b) doses lower than the STD doses administered over 3 days are ineffective in preventing relapse.     

Microtubules mobility affects the modulation of L-type I(Ca) by muscarinic and beta-adrenergic agonists in guinea-pig cardiac myocytes

To investigate the interaction of cytoskeleton with the receptor modulation of ionic currents, we studied the effect of muscarinic and beta-adrenergic stimulation in adult guinea-pig ventricular cardiac myocytes treated with paclitaxel and colchicine, two drugs that respectively stabilize or destabilize microtubules. We observed that the stabilization of microtubules with paclitaxel (1 microM for 1-4 h) did not markedly affect either the kinetics of I(Ca), or the stimulatory effect of isoproterenol (Iso, 1 microM); however paclitaxel significantly blunted the response to carbachol (CCh, 1 microM). In agreement with the electrophysiological measurements, Iso induced a similar enhancement of intracellular cAMP levels in both control and paclitaxel-treated cells, while the response to CCh 1 microM was significantly reduced in paclitaxel-treated cells. The reduction of muscarinic response induced by paclitaxel was also evident in atrial cells, in which the stimulation of I(KACh) by CCh 1 microM was reduced to about 10%. Compared to the muscarinic response, paclitaxel did not have significant effect on the purinergic (adenosine 1-10 microM) modulation of I(Ca). In contrast to paclitaxel, in colchicine-treated cells, I(Ca) was not enhanced by beta-adrenergic stimulation, but instead reduced by CCh, even in the absence of previous stimulation. In conclusion, our data suggest that microtubule stabilization significantly affects the muscarinic modulation of I(Ca), by interacting with the receptor or the G-protein rather than on the intracellular signaling cascade.     

Laboratory and field evaluation of rodent bait treated with fipronil for feed through and systemic control of Phlebotomus papatasi

The sand fly Phlebotomus papatasi is the main vector of Leishmania major, etiologic agent of zoonotic cutaneous leishmaniasis (ZCL), which is endemic in North Africa, the Middle East, and Asia. In North Africa, Meriones shawi is one of the two main reservoir hosts of L. major. P. papatasi populations are maintained in borrowing rodents such as M. shawi. Three fipronil-treated rodent baits were evaluated for systemic and feed through insecticidal activity against P. papatasi feeding on M. shawi. Through blood feeding bioassays, mortality rates of females P. papatasi increased with the concentration of fipronil in the rodent bait varying from 0.001% to 0.005%. In the laboratory, more than 90.0% of P. papatasi were killed within 48 h after blood feeding on the desert's jirds, M. shawi, treated up to 29 days prior with a single application of fipronil at a concentration of 0.001%, 0.0025% and 0.005%. Through larval bioassays, mortality rates of larvae that have fed on faeces of treated bait for M. shawi increase with the concentrations of fipronil. Faeces of orally-treated Meriones were significantly toxic to larvae for 5 weeks with a concentration of 0.005%. In the field, application of treated bait resulted in 80.0% reduction in the populations of P. papatasi up to 6 weeks after a single application of fipronil at a concentration of 0.005%. This is the first study to demonstrate field efficacy of fipronil-treated rodent baits for P. papatasi control and the first study to evaluate this approach in M. shawi, a principal ZCL reservoir host. These results suggest that fipronil-treated rodent baits can be used to effectively reduce the populations of P. papatasi associated with M. shawi in ZCL endemic areas.