Bioassay-guided fractionation and in vivo antiplasmodial effect of fractions of chloroform extract of Artemisia maciverae Linn

In the search for new plant-derived anti-malarial compounds, chromatographic fractions of chloroform extract of whole plants of Artemisia maciverae were tested in vivo using chloroquine resistant and chloroquine sensitive Plasmodium berghei NK 65 infected Swiss albino mice. One fraction and a sub-fraction of this were most active at 10/mg and cleared parasitemia in mice within 3 days. The different fractions and sub-fractions were tested with different reagents to determine the broad classes of compounds present. The active fraction tested positive for triterpenes and alkaloids, and the sub-fraction for only triterpenes. These tests suggest that the anti-malarial activities observed with these fractions may be due to these classes of compounds in the chloroform extract of the A. maciverae. Further chemical work is however required to characterize the active constituents.     

Suppressive effect of rice extract on Helicobacter pylori infection in a Mongolian gerbil model

Background Rice extract has been shown to protect gastric mucosa from stress-induced damage. In this study, the antibiotic effect and the anti-inflammatory effect of orally administered aqueous rice extract on Helicobacter pylori infection and H. pylori-induced gastritis, respectively, in Mongolian gerbils were investigated.Methods Fifty specific-pathogen-free male Mongolian gerbils, seven weeks old, were divided into four groups: uninfected, untreated animals (group A); uninfected, rice extract-treated animals (group B); H. pylori-infected, untreated animals (group C); and H. pylori-infected, rice extract-treated animals (group D). Group C and D animals were killed 12 weeks after H. pylori infection (i.e., at 19 weeks of age) and group A and B animals were also killed at age 19 weeks. The stomachs were removed for histopathological examination with hematoxylin-and-eosin staining and anti-5-bromo-2-deoxyuridine (BrdU) immunostaining, and to determine the bacterial burden. Serum anti-H. pylori antibody titers were also tested.Results In groups A and B, the gastric mucosa showed no inflammatory cell infiltration and a few BrdU-reactive cells. Group C animals developed marked chronic active gastritis in the gastric mucosa, and BrdU-labeled cells in the gastric mucosa markedly increased in number. In group D animals, a significant reduction occurred in the degree of neutrophilic polymorphonuclear cell infiltration into the gastric mucosa, in the BrdU-labeling indices of gastric epithelial cells, and in anti-H. pylori antibody titers in the serum (P < 0.01), compared with although H. pylori was not completely eradicated.Conclusions The rice extract was effective in suppressing inflammation and epithelial cell proliferation in the gastric mucosa in H. pylori-infected Mongolian gerbils. The rice extract has potential to exhibit a protective effect on H. pylori-related gastric mucosal diseases.     

Serum antibodies to enterohepatic Helicobacter spp. in patients with chronic liver diseases and in a population with high prevalence of H. pylori infection

BACKGROUND: Enteric Helicobacter species might be a risk factor for chronic liver and biliary tract diseases. AIMS: To analyse serum antibody levels to three enteric Helicobacter species in patients with various biliary tract and chronic liver diseases and compare results with corresponding parameters for an adult population group, known to have a high prevalence of Helicobacter pylori infection, and with healthy blood donors, to explore a possible association of enteric Helicobacter with chronic liver diseases. SUBJECTS: Sera of 90 patients with various chronic liver diseases, 121 Estonian adult persons and 68 blood donors were analysed. METHODS: Sera, previously tested for H. pylori were analysed for IgG to Helicobacter hepaticus, Helicobacter bilis and Helicobacter pullorum. ELISA was initially used for screening and exclusion of negative cases. Sera with positive ELISA results were further analysed by immunoblot. To remove cross-reactive antibodies between H. pylori and the enteric species, sera were pre-absorbed with lysed H. pylori cells. RESULTS: Liver patients showed a significantly higher seroprevalence to H. hepaticus and H. bilis, compared with the adult population group (p=0.0001 and 0.04, respectively), and to H. hepaticus, compared with blood donors (p=0.01). Patients with autoimmune hepatitis showed no significant antibody reactivity to the enteric Helicobacter spp. in contrast to patients with other chronic liver diseases. CONCLUSION: Patients with chronic liver diseases, except autoimmune hepatitis patients, showed increased antibody levels to H. bilis/H. hepaticus compared with the population and blood donors indicating a possible role of enteric Helicobacter in the natural course of chronic liver diseases. Immunoblot seems to be a promising method for serodiagnosis of infections with these fastidious pathogens.     

Natural infectivity of Anopheles species from the Pacific and Atlantic Regions of Colombia

Malaria is an important public health problem in Colombia. Among the major vectors in Colombia, Anopheles albimanus is recognized for its importance on the Pacific Coast where it is the predominant species; it is also found in the Atlantic Coast, although its vectorial role in this region is not clear. We examined the occurrence of An. albimanus in four localities of the Pacific and three of the Atlantic Coast. Morphological identification of problematic specimens was confirmed by a molecular assay. All identified mosquitoes at these sites, including An. albimanus, were also tested for malaria parasite infection. From 12,189 anophelines collected, 6370 were from the Pacific Coast, and corresponded to 99% An. albimanus, 0.8% Anopheles neivai, and three other species at <0.2%. From the Atlantic Coast we identified 5819 specimens with 61% An. albimanus, 36% Anopheles triannulatus s.l. and five other species at <2%. In both coasts, species present at lower percentages included several incriminated as vectors in neighboring countries. Six Pacific Coast specimens were infected with malaria parasites: four An. albimanus, two with Plasmodium vivax VK247, one with P. vivax VK210 and one with Plasmodium falciparum; two An. neivai with P. falciparum. Our data support the continued predominance of An. albimanus in the Pacific Coast, and demonstrate that this species is the most abundant in the Atlantic Coast as well.     

Functional assessment of compound mutations in the KCNQ1 and KCNH2 genes associated with long QT syndrome

BACKGROUND: Long QT syndrome (LQTS) is a cardiovascular disorder characterized by prolonged QTc time, syncope, or sudden death caused by torsades de pointes and ventricular fibrillation. We investigated the clinical and electrophysiologic phenotype of individual mutations and the compound mutations in a family in which different genotypes could be found. OBJECTIVES: The purpose of this study was to determine the impact of genotype-based diagnostic assessment in LQTS. METHODS: We used cascade screening and functional analyses to investigate the phenotype in a family with LQTS. The contributions of the compound mutations in the KCNQ1 and KCNH2 genes (KCNQ1 R591H, KCNH2 R328C) were analyzed by heterologous expression in Xenopus laevis oocytes using two-electrode voltage clamp and by confocal imaging. RESULTS: KCNH2 R328C did not show any functional phenotype whereas KCNQ1 R591H resulted in severe reduction of current. Neither wild-type nor mutant channels affected each other functionally in coexpression experiments. Therefore, a direct interaction between KCNQ1 and KCNH2 was ruled out under these conditions. CONCLUSION: Assessment of novel mutational findings in LQTS should include accurate genetic and functional analysis. Notably, appropriate studies are needed if two or more mutations in different genes are present in one proband. Our findings prompt reconsideration of the impact of compound mutations in LQTS families and reinforce the need for thorough functional evaluation of novel ion channel mutations before assignment of pathogenic status.     

The early effect of proton pump inhibitor therapy on the accuracy of the C-urea breath test

BACKGROUND: The intake of proton pump inhibitors may interfere with the reliability of the urea breath test. AIM: Prospective study to assess the accuracy of the urea breath test during the first days of therapy with proton pump inhibitors. PATIENTS: Thirty patients who needed to start proton pump inhibitors therapy and 53 volunteers. METHODS: A 13C-urea breath test was performed respectively before starting proton pump inhibitors therapy and every morning before its intake up until 10 days. The test was considered positive for values of 13CO2 > or = 3.0% delta over baseline. The coefficient of reproducibility for 95% interval of confidence of the urea breath test was calculated in both groups. RESULTS: Of the 30 patients receiving proton pump inhibitors, 47% were positive for Helicobacter pylori. Among these, 43% developed false negative breath tests in the first 10 days. False positive results occurred in 37.5% of H. pylori-negative subjects in the first 10 days. The coefficient of reproducibility of the urea breath test was significantly higher in the group treated with proton pump inhibitors (11.0 versus 1.8 for the control group, p < 0.0001). CONCLUSION: The intake of proton pump inhibitors impairs the accuracy of the 13C-urea breath test. False negative and false positive 13C-urea breath tests are common, occur as soon as after 1 day and increase with prolonged duration of treatment. The coefficient of reproducibility of the test in patients receiving proton pump inhibitors is not acceptable for clinical purpose and the test should not be performed once the medication has been started.     

Effects of culture medium and formulation on the larvicidal activity of the mosquito pathogen Lagenidium giganteum (Oomycetes: Lagenidiales) against Aedes aegypti

In this work, we examined the production of infective zoospores of Lagenidium giganteum in four culture media, and the larvicidal activity of the cultures was determined against Aedes aegypti larvae, as well as the effect of polymer encapsulation. Medium containing sunflower seed extract showed the greatest production of zoospores, 5.92 × 10⁶ zoospores/ml after six days of fermentation at 25 ± 2 °C and 150 rpm shaking. This culture tested against A. aegypti 1st stage larvae caused different mortality rates at 24, 48 and 72 h posttreatment. The LC₅₀ obtained was 43.9, 41.1 and 42.9 μl of total culture/ml, at 24, 48 and 72 h posttreatment respectively, while the culture grown in medium with soybean meal showed 3–5 times higher LC₅₀ values. Finally, the total culture including mycelium, zoospores and presporangia formulated with 2.5% pectin showed significantly higher mortality rates, around 100% more than the unformulated culture, whose values were from 40 to 1% at 3, 6, 9, and 12 d posttreatment in the bioassays carried out in the laboratory to determine residual activity.     

The effect of HLA class II, insulin and CTLA4 gene regions on the development of humoral beta cell autoimmunity

Aims/hypothesis The aim of this study was to explore the contribution of genetic factors to the emergence of beta-cell-specific humoral autoimmunity.Subjects and methods We analysed the effect of HLA class II, insulin (INS; –23 HphI variant) and cytotoxic T-lymphocyte-associated protein 4 (CTLA4 [+49 and CT60]) genes on the appearance of beta-cell-specific autoantibodies in a large population-based birth cohort recruited in Finland. Infants carrying increased risk HLA DQB1 genotypes were monitored for the appearance of autoantibodies (islet cell autoantibodies [ICA], insulin autoantibodies [IAA], glutamic acid decarboxylase autoantibodies [GADA] and islet antigen 2 antibodies [IA–2A]). Those who developed beta-cell-specific autoantibodies were studied (n=574, mean follow-up time: 4.9 years; range 0.5–9.3).Results IAA emerged at a higher rate in children with the –23 HphI AA INS genotype than in those carrying AT or TT variants (hazard ratio 2.1, 95% CI 1.4–2.9, p<0.001). This effect of the INS locus was present in both HLA DQB1 risk groups. The appearance of IAA showed a strong association also with the HLA DRB1*0401 allele (hazard ratio 13.1, 95% CI 1.8–93.4, p<0.001). The development of IA–2A was also somewhat accelerated by the DRB1*0401 variant (p=0.03). Isolated ICA positivity was independent of the HLA and INS genotypes. None of the humoral immune markers showed association with the CTLA4 gene.Conclusions/interpretation The INS and the DRB1 loci appear to contribute to the pathogenesis of type 1 diabetes by initiating/modifying insulin-specific autoimmunity. The emergence of IAA represents a crucial step in the development of beta cell autoimmunity in young children, in whom the appearance of GADA and IA–2A is linked to IAA.     

In vivo protective effect of the lectin from Canavalia brasiliensis on BALB/c mice infected by Leishmania amazonensis

In vivo administration of Canavalia brasiliensis lectin (at the time of infection, or maintained throughout the infection) reduced the lesions of highly susceptible BALB/c mice infected by Leishmania amazonensis. At the doses used C. brasiliensis lectin (ConBr) does not interfere with penetration or fate of Leishmania in the macrophages in vitro. Since Interferon-γ (IFN-γ) is the major macrophage activating factor, and considered a critical element in the successful immune response against leishmaniasis, we explored its participation in this phenomenon. ConBr either in vivo or in vitro induced IFN-γ production in normal or in leishmania-infected BALB/c mice. However we were unable to change the course of disease by in vivo IFN-γ administration (although IFN-γ preparations were effective in inducing a leishmanicidal effect in vitro on L. amazonensis-infected peritoneal macrophages). Additionally, IFN-γ neutralization with anti-IFN-γ monoclonal antibody did not alter the protection conferred by ConBr administration. These data show that lectin administration in vivo is protective in the otherwise unchecked L. amazonensis infection of BALB/c mice, and suggest that such effect is not mediated by IFN-γ.     

Digenetic trematodes of marine fishes from the Arabian Gulf off the coast of Kuwait. Family Bucephalidae Poche, 1907, and the description of a new species

Summary  Six species of Bucephalidae are reported: Subfamily Bucephalinae: Bucephalus sphyraenae Yamaguti, 1952 from Sphyraena obtusata and S. chrysotaenia (Sphyraenidae) (new host records); Bucephalus margaritae Ozaki and Ishibashi, 1934 from Atropus atropos, Scomberoides commersonianus, Carangoides malabaricus (Carangidae), Gerres filamentosus (Gerreidae) (new host record) and Sphyraena jello (new host record); Rhipidocotyle pseudorhombi n. sp. from Pseudorhombus arsius is characterized by and differs from its congeners by several characteristics including an elongate body, a rhynchus with 7 thin papillae, a long tuular caecum extending posteriorly to the ovarian level, goads in the posterior half of the body, and contiguous testes not separated by uterine coils. More specifically it differs from R. heptathelata and R. septapapillata by having a long cirrus sac relative to body length, tandem and more anterior testes. Subfamily Prosorhynchinae: Prosorhynchus pacificus Manter, 1940 from Epinephelus tauvina (Serranidae) and Gnathonodon speciosus (Carangidae) (new host record); P. epinepheli Yamaguti, 1939 from Epinephelus areolatus; P. manteri Srivastava, 1938 from Trichiurus lepturus (Trichiuridae). All species, except Prosorhynchus epinepheli represent new records from the Arabian Gulf.     

Analysis of telomere length and telomerase activity in tree species of various life-spans,and with age in the bristlecone pine <Emphasis Type="BoldItalic">Pinus longaeva</Emphasis>

Normal somatic cells have a finite replicative capacity. With each cell division, telomeres (the physical ends of linear chromosomes) progressively shorten until they reach a critical length, at which point the cells enter replicative senescence. Some cells maintain telomere length by the action of the telomerase enzyme. The bristlecone pine, Pinus longaeva, is the oldest known living eukaryotic organism, with the oldest on record turning 4770 years old in 2005. To determine what changes occur, if any, in telomere length and telomerase activity with age, and what roles, if any, telomere length and telomerase activity may play in contributing to the increased life-span and longevity of P. longaeva with age, as well as in other tree species of various life-spans, we undertook a detailed investigation of telomere length and telomerase activity in such trees. The results from this study support the hypothesis that both increased telomere length and telomerase activity may directly/indirectly contribute to the increased life-span and longevity evident in long-lived pine trees (2000–5000 year life-spans) compared to medium-lived (400–500 year life-span) and short-lived (100–200 year life-span) pine trees, as well as in P. longaeva with age.     

Infection rates and genotypes of Trypanosoma rangeli and T. cruzi infecting free-ranging Saguinus bicolor (Callitrichidae), a critically endangered primate of the Amazon Rainforest

Parasites of wild primates are important for conservation biology and human health due to their high potential to infect humans. In the Amazon region, non-human primates are commonly infected by Trypanosoma cruzi and T. rangeli, which are also infective to man and several mammals. This is the first survey of trypanosomiasis in a critically endangered species of tamarin, Saguinus bicolor (Callitrichidae), from the Brazilian Amazon Rainforest. Of the 96 free-ranging specimens of S. bicolor examined 45 (46.8%) yielded blood smears positive for trypanosomes. T. rangeli was detected in blood smears of 38 monkeys (39.6%) whereas T. cruzi was never detected. Seven animals (7.3%) presented trypanosomes of the subgenus Megatrypanum. Hemocultures detected 84 positive tamarins (87.5%). Seventy-two of 84 (85.7%) were morphologically diagnosed as T. rangeli and 3 (3.1%) as T. cruzi. Nine tamarins (9.4%) yielded mixed cultures of these two species, which after successive passages generated six cultures exclusively of T. cruzi and two of T. rangeli, with only one culture remaining mixed. Of the 72 cultures positive for T. rangeli, 62 remained as established cultures and were genotyped: 8 were assigned to phylogenetic lineage A (12.9%) and 54 to lineage B (87.1%). Ten established cultures of T. cruzi were genotyped as TCI lineage (100%). Transmission of both trypanosome species, their potential risk to this endangered species and the role of wild primates as reservoirs for trypanosomes infective to humans are discussed.     

The effect of immune sera from hamsters immunized with sandfly gut and whole body extract antigens on the fecundity and mortality of Phlebotomus duboscqi (Diptera: Psychodidae)

Phlebotomus duboscqi were fed on hamsters previously immunized with different concentrations of homogenized crude sandfly gut antigen and supernatant obtained from whole body extract. The humoral response in the rodents was quantified at different times post-immunization by the enzyme-linked immunosorbent assay. Sandflies were fed on either immunized or saline control hamsters and the effect of the blood meals on sandfly feeding, survival and fecundity was investigated. The humoral response in immunized hamsters as measured by the presence of P. duboscqi-specific IgG antibodies was significantly greater (P < 0.05) as compared to the controls. This difference was noted in sera collected on 15 and 25 days post-immunization. Sandflies fed on immunized hamsters had a significantly higher mortality (P < 0.05) and decreased egg production (P < 0.05) than those fed on unimmunized control hamsters.     

Is it possible to reduce endoscopy workload using age, alarm symptoms and H. pylori as predictors of peptic ulcer and oesophagogastric cancers?

OBJECTIVES: We examined referrals to oesophagogastroduodenoscopy and the impact of demographic and clinical variables to predict major findings (peptic ulcer, cancer) on oesophagogastroduodenoscopy. METHODS: We collected data on 3669 consecutive patients referred for oesophagogastroduodenoscopy. RESULTS: Dyspeptic and reflux symptoms constituted 80% of oesophagogastroduodenoscopy referrals. A major finding was observed in 419 patients (11.4%). The mean age of cancer patients was 72.7 years (95% confidence interval (CI) 70.0-76.5 years) and that of peptic ulcer patients 62.0 years (95% CI 60.5-63.5 years). Independent risk factors for a major finding were age >50 years (odds ratio (OR) 1.62, 95% CI 1.24-2.10), male sex (OR 1.38, 95% CI 1.11-1.72), ulcer-type pain (OR 2.33, 95% CI 1.80-3.02), weight loss (OR 1.70, 95% CI 1.14-2.53), anaemia (OR 1.82, 95% CI 1.38-2.40), bleeding symptoms (OR 3.27, 95% CI 2.26-4.75) and Helicobacter pylori (OR 2.49, 95% CI 2.00-3.11), whereas reflux symptoms were protective (OR 0.73, 95% CI 0.53-1.00). The area under receiver operating characteristic curve of age over 50 years with alarm symptoms to predict major finding was 0.68 (95% CI 0.65-0.71), which positive H. pylori status increased to 0.71 (95% CI 0.69-0.74). Of the major findings, 87.2% were detected in patients with risk factors. Major findings were detected in 15.1% patients with and 8.1% (p < 0.001) without alarm symptoms. CONCLUSIONS: Dyspeptic and reflux symptoms constitute the majority of oesophagogastroduodenoscopy workload. Discriminative power of alarm symptoms even with positive H. pylori status to detect peptic ulcer or cancer was low. Because of their low cancer risk, reflux and dyspeptic patients younger than 50 years can be treated without oesophagogastroduodenoscopy.     

Vector competence of Simulium oyapockense s.l. and S. incrustatum for Onchocerca volvulus: Implications for ivermectin-based control in the Amazonian focus of human onchocerciasis, a multi-vector-host system

Although it is now well established that in the Amazonian onchocerciasis focus, straddling between Venezuela and Brazil, the main vectors in the highland (hyperendemic) and lowland (hypoendemic) areas, are respectively Simulium guianense sensu lato Wise and S. oyapockense s.l. Floch and Abonnenc, investigation of the vectorial role of a third anthropophagic species, Simulium incrustatum Lutz has remained inconclusive. Here we compare the vector competence of S. incrustatum with that of S. oyapockense s.l. by conducting, in the Venezuelan part of the focus, a series of feeding experiments designed to analyze their relative: (a) microfilarial intakes when fed upon the same skin load; (b) proportions of microfilariae (mf) surviving damage inflicted by the cibarial armature (present in both species); and (c) infective (L3) larval outputs. Although the ability of S. oyapockense s.l. to ingest mf, for a given microfilaridermia, was markedly higher than that of S. incrustatum, the (density-dependent) proportions of those ingested mf that were damaged by the armature were also consistently higher, with the resulting output of L3 larvae being significantly lower in S. oyapockense s.l. than in S. incrustatum. These results indicate that S. incrustatum plays a more important role in onchocerciasis transmission in the Amazonian focus than previously realized. We discuss the implications of our findings for the control and elimination of onchocerciasis with mass administration of ivermectin in this focus, where the three main anthropophagic species often co-occur.     

DNA barcodes confirm the presence of a single member of the Anopheles maculipennis group in Morocco and Algeria: An. sicaulti is conspecific with An. labranchiae

Anopheles labranchiae Falleroni is the only member of the Maculipennis Group known to occur in northern Africa; however, confusion exists as to the taxonomic status of its junior synonym, An. sicaulti Roubaud (type locality: near Rabat, Morocco). Based on morphological and behavioural distinctions, it has been suggested that Moroccan populations have been isolated from other North African populations by the Atlas Mountains, and that Moroccan populations may represent An. sicaulti, originally described as a variety of An. maculipennis Meigen. DNA barcodes (658 bp of the mitochondrial COI gene) obtained from 89 An. maculipennis s.l. collected in Morocco (n = 79) and Algeria (n = 10) in 2007 and 2008 were used to determine if Moroccan populations are genetically isolated from those east of the Atlas Mountains (Algeria), and whether there is molecular evidence to support the presence of more than one member of the Maculipennis Group in the region. No evidence for speciation was found between Moroccan and Algerian populations, or within populations in northern Morocco. Moreover shared COI haplotypes between Algeria and Morocco indicate ongoing gene flow between populations in these countries, suggesting that the Atlas Mountains are not a boundary to gene flow in An. labranchiae. The synonymy of An. sicaulti with An. labranchiae is confirmed. That An. labranchiae comprises the same species in these North African countries is important for malaria control.     

Serum pepsinogen concentrations as a measure of gastric acid secretion in Helicobacter pylori-negative and -positive Japanese subjects

Background Although previous studies have indicated that serum pepsinogen I levels, as well as the pepsinogen I/II ratio, were positively correlated with maximal gastric output, the relationship may be different between Helicobacter pylori-negative and -positive subjects. The aim of this study was to investigate the relation between serum pepsinogen concentrations and gastric acid secretion in H. pylori-positive and -negative subjects separately. Methods The presence of H. pylori infection, the serum pepsinogen concentrations, and gastric acid secretion were investigated in 182 subjects without localized lesions in the upper gastrointestinal tract. Serum pepsinogen concentration was measured by radioimmunoassay, and maximal gastric acid output was estimated by an endoscopic gastrin test, as we have previously shown. Results In H. pylori-positive subjects, serum pepsinogen I levels and the pepsinogen I/II ratio were significantly correlated with gastric acid secretion, although the latter showed a better correlation (r = 0.40 and 0.53, respectively). On the other hand, in H. pylori-negative subjects, serum pepsinogen concentrations were well correlated with acid secretion (r = 0.57), but there was no relation between the pepsinogen I/II ratio and acid secretion. Conclusions The correlations between serum pepsinogens and gastric acid secretion differ, depending on the presence or absence of H. pylori infection. With the use of serum pepsinogens as a simple measure of gastric acid secretion, therefore, consideration of H. pylori infection status is needed. Because the determination of the acid secretory level has some clinical implications in both H. pylori-positive and -negative subjects, its estimation by serum pepsinogen concentrations can be of practical use.