Novel and highly informative Capsicum SSR markers and their cross-species transferability

This study was undertaken primarily to develop new simple sequence repeat (SSR) markers for Capsicum. As part of this project aimed at broadening the use of molecular tools in Capsicum breeding, two genomic libraries enriched for AG/TC repeat sequences were constructed for Capsicum annuum. A total of 475 DNA clones were sequenced from both libraries and 144 SSR markers were tested on cultivated and wild species of Capsicum. Forty-five SSR markers were randomly selected to genotype a panel of 48 accessions of the Capsicum germplasm bank. The number of alleles per locus ranged from 2 to 11, with an average of 6 alleles. The polymorphism information content was on average 0.60, ranging from 0.20 to 0.83. The cross-species transferability to seven cultivated and wild Capsicum species was tested with a set of 91 SSR markers. We found that a high proportion of the loci produced amplicons in all species tested. C. frutescens had the highest number of transferable markers, whereas the wild species had the lowest. Our results indicate that the new markers can be readily used in genetic analyses of Capsicum.

Separation-of-function mutation in HPC2, a member of the HIR complex in S. cerevisiae, results in derepression of the histone genes but does not confer cryptic TATA phenotypes

The HIR complex, which is comprised of the four proteins Hir1, Hir2, Hir3 and Hpc2, was first characterized as a repressor of three of the four histone gene loci in Saccharomyces cerevisiae. Using a bioinformatical approach, previous studies have identified a region of Hpc2 that is conserved in Schizosaccharomyces pombe and humans. Using a similar approach, we identified two additional domains, CDI and CDII, of the Hpc2 protein that are conserved among yeast species related to S. cerevisiae. We showed that the N terminal CDI domain (spanning amino acids 63-79) is dispensable for HIR complex assembly, but plays an essential role in the repression of the histone genes by recruiting the HIR complex to the HIR-dependent histone gene loci. The second conserved domain, CDII (spanning amino acids 452-480), is required for the stability of the Hpc2 protein itself as well as for the assembly of the HIR complex. In addition, we report a novel separation-of-function mutation within CDI of Hpc2, which causes derepression of the histone genes but does not confer other reported hir/hpc- phenotypes (such as Spt phenotypes, heterochromatin silencing defects and repression of cryptic promoters). This is the first direct demonstration that a separation-of-function mutation exists within the HIR complex.

The Saccharomyces cerevisiae histone chaperone Rtt106 mediates the cell cycle recruitment of SWI/SNF and RSC to the HIR-dependent histone genes

Background

In Saccharomyces cerevisiae, three out of the four histone gene pairs (HTA1-HTB1, HHT1-HHF1, and HHT2-HHF2) are regulated by the HIR co-repressor complex. The histone chaperone Rtt106 has recently been shown to be present at these histone gene loci throughout the cell cycle in a HIR- and Asf1-dependent manner and involved in their transcriptional repression. The SWI/SNF and RSC chromatin remodeling complexes are both recruited to the HIR-dependent histone genes; SWI/SNF is required for their activation in S phase, whereas RSC is implicated in their repression outside of S phase. Even though their presence at the histone genes is dependent on the HIR complex, their specific recruitment has not been well characterized. In this study we focused on characterizing the role played by the histone chaperone Rtt106 in the cell cycle-dependent recruitment of SWI/SNF and RSC complexes to the histone genes.

Methodology/Principal Findings

Using GST pull-down and co-immunoprecipitation assays, we showed that Rtt106 physically interacts with both the SWI/SNF and RSC complexes in vitro and in vivo. We then investigated the function of this interaction with respect to the recruitment of these complexes to HIR-dependent histone genes. Using chromatin immunoprecipitation assays (ChIP), we found that Rtt106 is important for the recruitment of both SWI/SNF and RSC complexes to the HIR-dependent histone genes. Furthermore, using synchronized cell cultures, we showed by ChIP assays that the Rtt106-dependent SWI/SNF recruitment to these histone gene loci is cell cycle regulated and restricted to late G1 phase just before the peak of histone gene expression in S phase.

Conclusions/Significance

Overall, these data strongly suggest that the interaction between the histone chaperone Rtt106 and both the SWI/SNF and RSC chromatin remodeling complexes is important for the cell cycle regulated recruitment of these two complexes to the HIR-dependent histone genes.

WD40 domain divergence is important for functional differences between the fission yeast Tup11 and Tup12 co-repressor proteins

We have previously demonstrated that subsets of Ssn6/Tup target genes have distinct requirements for the Schizosaccharomyces pombe homologs of the Tup1/Groucho/TLE co-repressor proteins, Tup11 and Tup12. The very high level of divergence in the histone interacting repression domains of the two proteins suggested that determinants distinguishing Tup11 and Tup12 might be located in this domain. Here we have combined phylogenetic and structural analysis as well as phenotypic characterization, under stress conditions that specifically require Tup12, to identify and characterize the domains involved in Tup12-specific action. The results indicate that divergence in the repression domain is not generally relevant for Tup12-specific function. Instead, we show that the more highly conserved C-terminal WD40 repeat domain of Tup12 is important for Tup12-specific function. Surface amino acid residues specific for the WD40 repeat domain of Tup12 proteins in different fission yeasts are clustered in blade 3 of the propeller-like structure that is characteristic of WD40 repeat domains. The Tup11 and Tup12 proteins in fission yeasts thus provide an excellent model system for studying the functional divergence of WD40 repeat domains.

[Leg ulcer clinic at Santa Marta Hospital]

Leg ulcers constitute a highly prevalent pathology in society, and are particularly common in the Angiology and Vascular Surgery outpatient clinic. The prevalence of these patients in this Department result from the fact that 70% of them display superficial and/or deep venous insufficiency of the lower limbs. To address this problem and optimize the therapeutic approaches available to the Chronic Leg Ulcer (CLU) patients, the Department of Angiology and Vascular Surgery has created, in March 2005, an appointment specific to CLU patients. An evaluation protocol was developed, including ulcer characterization, standardization of the conservative treatment, followed by surgical intervention, whenever required. The results obtained were evaluated 18 months after the onset of this protocol. Analysis of the results revealed that the majority of the patients responded positively to the new therapeutic approach, with closure of the ulcer in 43% of the patients and a significant improvement detected for an additional 30%. Furthermore, it was observed that a detailed evaluation of these patients should be regarded as a whole, followed by a standardized and targeted approach, resulting in a particularly successful approach on the treatment of this pathology.

Mechanism of Transcription Factor Recruitment by Acidic Activators

Many transcriptional activators are intrinsically unstructured yet display unique, defined conformations when bound to target proteins. Target-induced folding provides a mechanism by which activators could form specific interactions with an array of structurally unrelated target proteins. Evidence for such a binding mechanism has been reported previously in the context of the interaction between the cancer-related c-Myc protein and the TATA-binding protein, which can be modeled as a two-step process in which a rapidly forming, low affinity complex slowly converts to a more stable form, consistent with a coupled binding and folding reaction. To test the generality of the target-induced folding model, we investigated the binding of two widely studied acidic activators, Gal4 and VP16, to a set of target proteins, including TATA-binding protein and the Swi1 and Snf5 subunits of the Swi/Snf chromatin remodeling complex. Using surface plasmon resonance, we show that these activator-target combinations also display bi-phasic kinetics suggesting two distinct steps. A fast initial binding phase that is inhibited by high ionic strength is followed by a slow phase that is favored by increased temperature. In all cases, overall affinity increases with temperature and, in most cases, with increased ionic strength. These results are consistent with a general mechanism for recruitment of transcriptional components to promoters by naturally occurring acidic activators, by which the initial contact is mediated predominantly through electrostatic interactions, whereas subsequent target-induced folding of the activator results in a stable complex.

Acute Ischemic Hepatitis in Aortocaval Fistula

OBJECTIVES

To characterise liver dysfunction in patients with aortocaval fistula.

DESIGN

Retrospective study.

MATERIALS

All four patients operated on for aortocaval fistula between 1999 and 2003. Three were males with ruptured abdominal aortic aneurysm (AAA). One was a female who underwent lumbar disk surgery. Four patients operated on for ruptured AAA were used as controls.

METHODS

Measurement of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH) and creatinine from the preoperative period until full recovery.

RESULTS

The median delay between the presumed formation of the fistula and surgery was 2 days (range 1-3 days). High levels of AST, ALT and LDH were observed in all patients, starting from the preoperative period, reaching the maximum on the first two postoperative days and normalising thereafter. Median peak values were: AST=4256 IU/l (range 816-7779), ALT=2487 IU/l (range 960-5645) and LDH=15165 IU/l (range 3122-32361). Serum creatinine also sustained alterations with a similar time course. Median peak values were: 256 micromol/l (range 230-468). All the patients survived.

CONCLUSIONS

Acute ischemic hepatitis appears to be a consistent or, at least, a common complication of aortocaval fistula. Although a concern during the perioperative period, its course is benign and fully resolves upon successful surgery.

Relationships in Ananas and other related genera using chloroplast DNA restriction site variation

Chloroplast DNA (cpDNA) diversity was examined using PCR-RFLP to study phylogenetic relationships in Ananas and related genera. One hundred fifteen accessions representing the seven Ananas species and seven other Bromelioideae including the neighboring monospecific genus Pseudananas, two Pitcairnioideae, and one Tillandsioideae were included in the study. Eight primers designed from cpDNA were used for generating fragments. Restriction by 18 endonucleases generated 255 variable fragments. Dissimilarities were calculated from the resulting matrix using the Sokal and Michener index and the neighbor-joining method was used to reconstruct the diversity tree. Phylogenetic reconstruction was attempted using Wagner parsimony. Phenetic and cladistic analyses gave consistent results. They confirm the basal position of Bromelia in the Bromelioideae. Ananas and Pseudananas form a monophyletic group, with three strongly supported sub-groups, two of which are geographically consistent. The majority of Ananas parguazensis accessions constitute a northern group restricted to the Rio Negro and Orinoco basins in Brazil. The tetraploid Pseudananas sagenarius joins the diploid Ananas fritzmuelleri to constitute a southern group. The third and largest group, which includes all remaining species plus some accessions of A. parguazensis and intermediate phenotypes, is the most widespread and its distribution overlaps those of the northern and southern groups. Ananas ananassoides is dominant in this sub-group and highly variable. Its close relationship to all cultivated species supports the hypothesis that this species is the wild ancestor of the domesticated pineapple. The data indicate that gene flow is common within this group and scarcer with both the first and second groups. Comparison of cpDNA data with published genomic DNA data point to the hybrid origin of Ananas bracteatus and support the autopolyploidy of Pseudananas. The Ananas-Pseudananas group structure and distribution are consistent and we propose a scenario based on the refugia hypothesis to explain our data. These results and hypotheses bring some interesting points to consider in the current discussion on Ananas taxonomy.

[Valvular transposition in patients with ulcers of the lower limbs following post thrombotic syndromes]

Venous ulcers in patients with post thrombotic syndromes are complex situations with multiple therapeutic options. They are responsible for high morbidity rates, conservative treatment is very slow and recurrences are very common. Deep venous reconstructive surgery is an alternative, but it should be based on the morphologic and functional aspects of the venous system and only adopted after a very careful study, including venography. The authors describe a morphological "pattern", found in some of these patients and related to the competence of the saphenous femoral junction, rendering possible to perform a valvular transposition. Seven patients with post thrombotic ulcers who have been treated during the last 6 years in which the pattern already described was detect, underwent a transposition of the superficial femoral vein, to the great saphenous vein and when necessary complemented with skyn grafts. Before the operation all patients had ulcers with more than 3 cm in size (3.2-5.4 cm) and with more than 4 months duration (4-16 months). All ulcers healed in the postoperative period (mean time 28 days). All patients have been reevaluated in 2003 and it was diagnosed the thrombosis of two procedures, one of them with the recurrence of the ulcer who healed with conservative treatment. The authors consider this method as a very easy technique to perform, although rarely used, and a valid alternative in a highly selected group of patients.

Leishmanicidal activity of two canthin-6-one alkaloids, two major constituents of Zanthoxylum chiloperone var. angustifolium

The crude alkaloidal extract of Zanthoxylum chiloperone stem bark exhibited in vitro activity against various strains of Leishmania ssp. at 100 microg/ml. Two active major constituents were isolated and identified as canthin-6-one and 5-methoxycanthin-6-one. The effect of these compounds was also tested in an in vivo assay using BALB/c mice infected with Leishmania amazonensis. The mice were treated for 5 weeks postinfection with these alkaloids by oral (14 days) or intralesional route (4 days) at 10 mg/kg daily. The reference drug, N-methylglucamine antimonate was administered by subcutaneous injections at 100 mg/kg for 10 days. Intralesional administration of canthin-6-one reduced the parasite burden but not significantly when it was compared with the untreated group, while the reference drug reduced by 91% the parasite loads in the lesion.

Experimental treatment of chronic Trypanosoma cruzi infection in mice with 2-n-propylquinoline

It was reported previously that 2-n-propylquinoline was active against the epimastigote form of Trypanosoma cruzi. The effects of oral treatments with benznidazole and 2-n-propylquinoline were evaluated in Balb/c mice infected with T. cruzi chronically. The reference drug and 2-n-propylquinoline were administered 60 days post-infection for 30 days at 25 mg/mL. At 35 days post-treatment, the serological tests (ELISA) of the 2-n- propylquinoline-treated mice were significantly different from the controls (p = 0.01) and the benznidazole-treated mice (p = 0.03), while this was not the case at 85 days post-treatment. These results are encouraging for continuing the investigation of other analogues of 2-n-propylquinoline in experimental chronic Chagas' disease.

Development and mapping of Oryza glumaepatula-derived microsatellite markers in the interspecific cross Oryza glumaepatula x O. sativa

Wild germplasm of domesticated crops is a source of genetic variation little utilized in breeding programs. Interspecific crosses can potentially uncover novel gene combinations that can be important for quantitative trait analysis. The combined use of wide crosses and genetic maps of chromosomal regions associated with quantitative traits can be used to broaden the genetic basis of rice breeding programs. Oryza glumaepatula is a diploid (AA genome) wild rice species native from South and Central America. A genetic map was constructed with 162 PCR-based markers (155 microsatellite and 7 STS markers) using a backcross population derived from the cross O. glumaepatula, accession RS-16 from the Brazilian Amazon Region x O. sativa BG-90-2, an elite rice inbred line. The map included 47 new SSR markers developed from an O. glumaepatula genomic library enriched for AG/TC sequences. All SSR markers were able to amplify the O. sativa genome, indicating a high degree of SSR flanking region conservation between O. glumaepatula and O. sativa species. The map covered 1500.4 cM, with an average of one marker every 10 cM. Despite some chromosomes being more densely mapped, the overall coverage was similar to other maps developed for rice. The advantage to construct a SSR-based map is to permit the combination of the speed of the PCR reaction, and the codominant nature of the SSR marker, facilitating the QTL analysis and marker assisted selection for rice breeding programs.

Role of the hepatic function in the development of the pyrogenic tolerance to muramyl dipeptide

We have demonstrated that the hepatic function may have an important role in the development of tolerance to the pyrogenic effect induced by endotoxin. To further investigate if the role of the hepatic function in the development of tolerance also extends to that induced by other pyrogenic stimuli, we investigated the effect of galactosamine, a specific inhibitor of the hepatic protein synthesis, on the development of tolerance to the pyrogenic effect induced by muramyl dipeptide (MDP) in rats. Pyrogenic tolerance was observed after the second intravenous or intraperitoneal injection of MDP (500 microgram/kg), 24 h after the first injection, similar to what was observed with endotoxin. Pyrogenic tolerance was abolished when galactosamine (300 mg/kg ip) was injected simultaneously with MDP (500 microgram/kg iv) on the first day. When uridine (600 mg/kg ip) was administered simultaneously with galactosamine (300 mg/kg ip) and the first injection of MDP (500 microgram/kg ip), pyrogenic tolerance was again observed after the second injection of the peptidoglycan. In conclusion, the hepatic function may not be important only for the development of tolerance to endotoxin, but also to a totally different pyrogenic stimulus such as MDP.

Analysis of random and specific sequences of nuclear and cytoplasmic DNA in diploid and tetraploid american wild rice species (Oryza spp.)

A sample of American wild rice and other accessions of the genus Oryza were studied at polymorphic regions of nuclear, mitochondrial, and chloroplastic genomes. First, flow cytometry, genome-specific RAPD markers, and chromosome counting were utilized to verify the original ploidy and classification of 230 accessions studied. Based on these methods, 8% of the accessions were considered to be misclassified either taxonomically or as a result of contamination. Second, a fine resolution analysis was conducted at genomic regions sampled at random by RAPD markers and at specific sites of the chloroplast and mitochondrial DNA by cleaved amplified polymorphic sequence (CAPS) analysis. Phylogenetic trees resulting from phenetic and cladistic analyses of RAPD, cpDNA, and mtDNA polymorphisms were obtained. The results indicated that the American diploid species O. glumaepatula should be considered an individual species, distinct from O. rufipogon, and confirmed that the American tetraploid species (O. alta, O. grandiglumis, and O. latifolia) belong to the O. officinalis complex. The data indicate that these species should still be treated as a group rather than as three distinct species and that their closest relative is a CC-genome species. It was estimated that the diploid and tetraploid American species diverged from O. sativa - O. nivara (AA genome) and CC- and BBCC-genome species, respectively, 20 million years ago.

Brazilian population database for the 13 STR loci of the AmpFlSTR Profiler Plus and Cofiler multiplex kits

Allele frequencies for the 13 STR core loci (D3S1358, VWA, FGA, D8S1179, D21S11, D18S51, D5S818, D13S317, D7S820, CSF1PO, TPOX, THO1 and D16S539) included in the AmpFlSTR((R)) Profiler Plus and AmpFlSTR((R)) Cofiler kits were obtained for a sample of 700-800 genetically unrelated Brazilians. The expected performance of these loci for personal identification and paternity testing in the Brazilian population was estimated.

Cryptofolione derivatives from Cryptocarya alba fruits

Cryptofolione (1) and the new cryptofolione derivative 6-(4,6-dimethoxy-8-phenyl-octa-1,7-dienyl)-4-hydroxy-tetrahydro-pyran-2-one (2) were isolated from the fruits of Cryptocarya alba. The structures were elucidated by spectroscopic methods. Cryptofolione showed activity towards Trypanosoma cruzi trypomastigotes, reducing their number by 77% at 250 microg mL(-1). Cryptofolione showed moderate cytotoxicity in both macrophages and T. cruzi amastigotes. It also displayed a mild inhibitory effect on the promastigote form of Leishmania spp. As both cytotoxic and trypanocidal effects are similar, the compound presented little selectivity in our assay models.

Evidence that platelet-derived growth factor may be a novel endogenous pyrogen in the central nervous system

Platelet-derived growth factor (PDGF) exerts neurotrophic and neuromodulatory actions in the mammalian central nervous system (CNS). Like the cytokines, PDGF primarily signals through tyrosine phosphorylation-dependent pathways that activate multiple intracellular molecules including Janus family kinases. We previously showed that microinjection of PDGF-BB into the lateral ventricle induced a febrile response in rats that was reduced by pretreatment with Win 41662, a potent inhibitor of PDGF receptors (Pelá IR, Ferreira MES, Melo MCC, Silva CAA, and Valenzuela CF. Ann NY Acad Sci 856: 289-293, 1998). In this study, we further characterized the role of PDGF-BB in the febrile response in rats. Microinjection of PDGF-BB into the third ventricle produced a dose-dependent increase in colonic temperature that peaked 3-4 h postinjection. Win 41662 attenuated fever induced by intraperitoneal injection of bacterial lipopolysaccharide, suggesting that endogenous PDGF participates in the febrile response to this exogenous pyrogen. Importantly, febrile responses induced by tumor necrosis factor-alpha, interleukin-1beta, and interleukin-6 were unchanged by Win 41662. Both indomethacin and dexamethasone blocked the PDGF-BB-induced increase in colonic temperature, and, therefore, we postulate that PDGF-BB may act via prostaglandin- and/or inducible enzyme-dependent pathways. Thus our findings suggest that PDGF-BB is an endogenous CNS mediator of the febrile response in rats.

Efficacy of the bisbenzylisoquinoline alkaloids in acute and chronic Trypanosoma cruzi murine model

We have shown previously that daphnoline and cepharanthine are active against Trypanosoma cruzi and inhibited trypanothione reductase. The effects of oral treatments with daphnoline, cepharanthine and benznidazole were examined in Balb/c mice infected with T. cruzi acutely and chronically. In acute infections, parasitaemia was significantly reduced in the daphnoline-treated mice compared with controls and benznidazole-treated mice. The parasitological cure rate was increased in mice treated with daphnoline. Fifty days after infection, the negative serological response in both models was significantly different for the three tested drugs. Daphnoline showed the highest negative serological rate (48%). In chronically infected mice treated with daphnoline, we were unable to detect parasites in 70% of mice. The results obtained of oral treatment of daphnoline suggest that this bisbenzylisoquinoline may be useful in the treatment of acute and chronic Chagas' disease. This was not seen with cepharanthine, an excellent trypanothione reductase inhibitor.

Myxoma of the mitral valve

Only rarely do myxomas originate from the mitral valve. This is the report of a 49-year-old woman presenting with congestive heart failure. The diagnosis of an intracardiac tumor involving the anterior cuspid of the mitral valve was made by transesophageal echocardiography. The patient underwent surgery for tumor resection and plasty of the valve was made with reconstruction and preservation of the valve. The diagnosis of myxoma was confirmed by histology. This is the 23rd case of myxoma of the mitral valve reported in the literature.

Acetogenins and other compounds from Rollinia emarginata and their antiprotozoal activities

Bioactivity-directed fractionation of the MeOH extract of the stem barks of Rollinia emarginata resulted in the isolation of six compounds, four acetogenins, rolliniastatin-1, sylvaticin, squamocin, and rollidecin B, one lignan, lirioresinol B, and an oxoaporphine, liriodenin. Their structures were determined by spectroscopic analysis and their in vitro leishmanicidal and trypanocidal properties are reported.

Chagas disease vector control through different intervention modalities in endemic localities of Paraguay

In a field study carried out in three rural communities in Paraguay in a zone endemic for Chagas disease, we implemented three different vector control interventions--spraying, housing improvement, and a combination of spraying plus housing improvement--which effectively reduced the triatomine infestation. The reduction of triatomine infestation was 100% (47/47) in the combined intervention community, whereas in the community where housing improvement was carried out it was 96.4% (53/55). In the community where fumigation alone was used, the impact was 97.6% (40/41) in terms of domiciliary infestation. In all the houses where an intervention was made, an 18-month follow-up showed reinfestation rates of less than 10%. A serological survey of the population in the pre- and post-intervention periods revealed a shift in positive cases towards older age groups, but no significant differences were observed. The rate of seroconversion was 1.3% (three new cases) in the community with housing improvement only, but none of these cases could have resulted from vector transmission. The most cost-effective intervention was insecticide spraying, which during a 21-month follow-up period had a high impact on triatomine infestation and cost US$ 29 per house as opposed to US$ 700 per house for housing improvement.

Experimental treatment of cutaneous leishmaniasis with argentilactone isolated from Annona haematantha

From the hexanic extract of roots of Annona haematantha an alpha,beta-unsaturated delta-lactone was isolated and identified as argentilactone. This compound exhibited in vitro activity against various strains of Leishmania ssp. at 10 micrograms/ml. BALB/c mice infected with Leishmania amazonensis were treated four weeks after infection with argentilactone by oral or subcutaneous routes for 14 days at 25 mg/kg daily. The reference drug, N-methylglucamine antimonate, was administered by subcutaneous injections at 100 mg/kg for 14 days. In these conditions, argentilactone showed the same efficacy as the reference drug, reducing by 96% the parasite loads in the lesion and by 50% the parasite burden in spleen.

Activity of compounds isolated from Chilean lichens against experimental cutaneous leishmaniasis

Three secondary metabolites isolated from Chilean lichens, (+) usnic acid, pannarine and 1'-chloropannarine, were tested against promastigotes forms of three strains of Leishmania ssp. Pannarine and 1'-chloropannarine exhibited in vitro activity at 50 micrograms/ml and (+) usnic acid at 25 micrograms/ml. BALB/c mice infected with Leishmania amazonensis were treated 4 weeks post-infection with (+) usnic acid by subcutaneous or oral routes for 15 days at 25 mg/kg or by five intralesional injections at interval of 4 days at 25 mg/kg of body weight. The reference drug, N-methylglucamine antimonate (Glucantime), was administered by subcutaneous injections (regimens of 28 mg of pentavalent antimony) for 15 days. The subcutaneous and oral treatments with (+) usnic did not produce any effect, but by intralesional administration we observed a significant effect that reduced by 43.34% the weight lesions and by 72.28% the parasites loads in infected footpads.

In vivo efficacy of oral and intralesional administration of 2-substituted quinolines in experimental treatment of new world cutaneous leishmaniasis caused by Leishmania amazonensis

The antileishmanial efficacies of 2-n-propylquinoline, chimanines B and D, 2-n-pentylquinoline, 2-phenylquinoline, 2-(3,4-methylenedioxyphenylethyl) quinoline, and two total alkaloidal extracts of Galipea longiflora were evaluated in BALB/c mice infected with Leishmania amazonensis or Leishmania venezuelensis. Animals were treated for 4 to 6 weeks postinfection with a quinoline by the oral route at 50 mg/kg of body weight twice daily for 15 days or by five intralesional injections at intervals of 4 days with a quinoline at 50 mg/kg of body weight. The reference drug, N-methylglucamine antimonate (Glucantime), was administered by subcutaneous or intralesional injection (regimens of 14, 28, or 56 mg of pentavalent antimony [Sbv] per kg of body weight daily). Twice-daily oral treatment with chimanine B at 50 mg/kg resulted in a decrease in lesion weight by 70% (P < 0.001) and a decrease in the parasite loads by 95% (P < 0.001). Five injections of chimanine B at intervals of 4 days reduced the lesion weight by 74% and the parasite loads in the lesion by 90% compared with the values for the group of untreated mice. Subcutaneous administration of N-methylglucamine antimonate at 28 mg of Sbv kg per day for 15 days reduced the parasite burden by 95% (P < 0.001), and five intralesional injections at the same concentration reduced the parasite burden by 96% (P < 0.001). Other 2-substituted quinolines, 2-n-propylquinoline administered by the oral and intralesional routes, 2-phenylquinoline administered by the oral route, 2-n-pentylquinoline administered by intralesional injection, and two total alkaloidal extracts of G. longiflora administered by the oral route, had intermediate effects. These findings suggest that chimanine B may be chosen as a lead molecule in the development of oral therapy against leishmaniasis.

Trypanosoma cruzi: polymerase chain reaction-based detection in dried feces of Triatoma infestans

PCR was employed to detect Trypanosoma cruzi DNA in Triatoma infestans dry fecal spots collected on filter papers. Both insects fed on experimentally infected monkeys and insects collected in a Paraguayan endemic area for Chagas' disease were examined. When the insects fed on a chronically infected monkey with low parasitemia as revealed by direct microscopic observation (DMO), T. cruzi was detected in the insect feces by PCR as soon as 2 days postfeeding. When the same experiment was performed on monkeys with parasitemia levels below the limit of detection by DMO, the degree of positivity found through PCR-Southern hybridization, applied on Day 8 postfeeding, was superior to that obtained through xenoculture. These results suggest that PCR can be used to speed the xenodiagnosis results with great sensitivity. On the other hand, when applied to the feces of triatomines collected in the field, 84% were positive by PCR-Southern hybridization, whereas only 26% were positive by DMO. Therefore, PCR could also be applied to the monitoring of the infection status of triatomines which infest rural dwellings by examining only the feces left on paper sensors hung on the walls of the houses.

Characterization of Paraguayan Trypanosoma cruzi strains isolated from acute patients of Chagas disease

Five Paraguayan Trypanosoma cruzi strains, isolated from acute chagasic patients, were studied by their behavior in BALB/c mice, metacyelogenesis, bio-metry of metacyclic forms and lectin agglutination. Early and intermediate parasitemic peaks were observed and the strains did not show high virulence. Metacyclogenesis capacity was not higher than 50% in all cases and there were no considerable differences in the biometry. They all belong to WGA-type strains according to the lectin agglutination assays except for one strain that agglutinated with WGA and PNA lectins. Although previous schizodeme analysis of these strains showed rather homogeneous profiles, biological features were quite heterogeneous.

Residual effect of lambdacyhalothrin on Triatoma infestans

Insecticidal residual effect and triatomine infestation rates in houses of a community fumigated with lambdcyhalothrin (Icon) are reported. No mortality was observed in 5th-instar Triatoma infestans nymphs in 72-hr exposure test on three different surfaces, one month after fumigation for a dose of 31.5 mg am/m2. However, during post-exposure observation a mortality of 60% was recorded for those insect exposed on sprayed woodboard. The results observed with mud-containing treated walls, were markedly poorer (0% of mortality). Twelve month after spraying 40% of mortality was observed on first-instar T. infestans nymphs in 72-hr exposure test on woodboard, but lower mortality rates were observed in mud-containing materials. When the effect of deltamethrin (109 mg ai/m2) and lambdcyhalothrin (94 mg ai/m2) was compared, the former did not appear to be superior at similar loads. Both have showed a mortality rate of 30% on 5th-instar T. infestans nymphs three months post-fumigation. The dose utilized in the field fumigation was enough to get a significant (p < 0.0001) control of triatomine domestic infestation, since it was sufficient to keep 95% of the houses uninfested throughout 21 months following treatment, when compared with baseline situation. A remarkable knock-down effect on adult and nymphs forms of the insect and a high in situ mortality were observed as a result of its application, even at very low doses.

Mapping loci controlling vernalization requirement and flowering time in Brassica napus

Rapeseed cultivars (Brassica napus L.) can be classified into annual and biennial groups according to their requirement for vernalization in order to induce flowering. The genetic control of these phenotypic differences is not well understood, but this information could be valuable for the design of breeding approaches to accelerate rapeseed improvement. In order to map loci controlling this variation, a doubled haploid population, derived from a cross between annual and biennial cultivars, was evaluated for vernalization requirement and days-to-flowering in a replicated field experiment using three treatments: no vernalization, 4 weeks of vernalization and 8 weeks of vernalization. A linkage map of 132 RFLP loci was used to locate loci controlling these traits. Marker segregation in one region of linkage group 9 was strongly associated with the annual/biennial growth habit in the unvernalized treatment and with days-to-flowering in all three treatments. Two other regions with smaller effects on days-to-flowering were also identified.

[Culicidae of Itaipu lake, in the Paraná river, southern Brazil]

Mosquito catches were made in Guaíra county, Paraná State, southern Brazil, in the vicinity of Itaipu dam, from January to December 1991. The catches were made with a Shannon light trap and human bait. The Shannon light trap was installed beside the highway that used, formerly, to lead to the Sete Quedas cataracts and the human bait was used in the urban area. Data about the Culicidae fauna were obtained as to predominant species, seasonal variation, time of highest density and affinity with human host. Forty-one species were identified as belonging to the Anopheles, Aedes, Aedomyia, Coquillettidia, Culex, Mansonia, Psorophora and Uranotaenia genera. With the Shannon light trap 21,280 mosquitoes were caught and with human bait 1,010. In the catches made with the Shannon light trap, Coquillettidia shannoni, Mansonia humeralis, Anopheles trianulatus, Aedes scapularis and Anopheles albitarsis accounted for 82.78% of all mosquitoes taken. In the catches made on human bait the highest densities of these mosquitoes occurred between 7 p.m. and 9 p.m. Aedes scapularis, Mansonia humeralis and Anopheles albitarsis represented 91.21% of all mosquitoes caught with human bait. The highest densities of Aedes scapularis, on human bait, were found between 8 p.m. and 9 p.m. and those of Mansonia humeralis and Anopheles albitarsis between 6 p.m. and 7 p.m. Among the genera caught with the Shannon light trap Coquillettidia shannoni, Mansonia humeralis and Anopheles albitarsis were most frequent in April, Anopheles triannulatus in January and Aedes scapularis in February.

RFLP mapping of Brassica napus using doubled haploid lines

The combined use of doubled haploid lines and molecular markers can provide new genetic information for use in breeding programs. An F1-derived doubled haploid (DH) population of Brassica napus obtained from a cross between an annual canola cultivar ('Stellar') and a biennial rapeseed ('Major') was used to construct a linkage map of 132 restriction fragment length polymorphism loci. The marker loci were arranged into 22 linkage groups and six pairs of linked loci covering 1016 cM. The DH map was compared to a partial map constructed with a common set of markers for an F2 population derived from the same F1 plant, and the overall maps were not significantly different. Comparisons of maps in Brassica species suggest that less recombination occurs in B. napus (n = 19) than expected from the combined map distances of the two hypothesized diploid progenitors, B. oleracea (n = 9) and B. rapa (n=10). A high percentage (32%) of segregating marker loci were duplicated in the DH map, and conserved linkage arrangements of some duplicated loci indicated possible intergenome homoeology in the amphidiploid or intragenome duplications from the diploid progenitors. Deviation from Mendelian segregation ratios (P < 0.05) was observed for 30% of the marker loci in the DH population and for 24% in the F2 population. Deviation towards each parent occurred at equal frequencies in both populations and marker loci that showed deviation clustered in specific linkage groups. The DH lines and molecular marker map generated for this study can be used to map loci for agronomic traits segregating in this population.

Comparison of RFLP and RAPD markers to estimating genetic relationships within and among cruciferous species

Restriction fragment length polymorphism (RFLP) and random amplified polymorphic DNA (RAPD) markers are being used widely for evaluating genetic relationships of crop germplasm. Differences in the properties of these two markers could result in different estimates of genetic relationships among some accessions. Nuclear RFLP markers detected by genomic DNA and cDNA clones and RAPD markers were compared for evaluating genetic relationships among 18 accessions from six cultivated Brassica species and one accession from Raphanus sativus. Based on comparisons of genetic-similarity matrices and cophenetic values, RAPD markers were very similar to RFLP markers for estimating intraspecific genetic relationships; however, the two marker types gave different results for interspecific genetic relationships. The presence of amplified mitochondrial and chloroplast DNA fragments in the RAPD data set did not appear to account for differences in RAPD- and RFLP-based dendrograms. However, hybridization tests of RAPD fragments with similar molecular weights demonstrated that some fragments, scored as identical, were not homologous. In all these cases, the differences occurred at the interspecific level. Our results suggest that RAPD data may be less reliable than RFLP data when estimating genetic relationships of accessions from more than one species.

[Mosquitos of peri and extradomiciliary environments in the southern region of Brazil]

Mosquitoes were collected on Sonho Real farm, Querência do Norte county, Paraná State, Brazil, using human bait and Falcão traps between June 1989 and May 1990. The fauna composition, monthly density, hours of major density, human attraction and presence of mosquitoes in domestic animal shelters were investigated. 5,923 mosquitoes of the genera Aedes, Aedomyia, Anopheles, Coquillettidea, Culex, Mansonia, Psorophora, Sabethes and Uranotaenia were collected. 33 species of mosquitoes were identified and among them Aedes scapularis, Anopheles albitarsis, Aedomyia squamipennis, Coquillettidea lynchi, Mansonia titillans e Coquillettidea venezuelensis were predominant. All these species were captured mainly on human bait, except Aedomyia squamipennis that was captured in domestic animal shelters. With regard to all the mosquitoes captured (5,923), their major period of activity was between 18 and 19 hours and April was the month of greatest density.

[Phlebotomine behavior in forest and extraforest environments, in an endemic area of American cutaneous leishmaniasis in northern Paraná State, southern Brazil]

Between November 1988 and April 1990, 75,637 phlebotomines were captured with the use of Falcão light traps on Palmital farm in the north of Paraná State, Brazil. Fifteen species were represented. The percentage of 95.8% of the insects were captured within the domiciliary area and the remaining 4.2% in the forest environment. The percentage of 62 were captured in one single Falcão light trap installed in a henhouse, where Blancasmya migonei predominated. In all the other traps Psychodopygus whitmani was predominant. B. migonei, P. whitmani, Pintomyia pessoai, Pintomyia fischeri and Psychodopygus intermedius are highly significant vectors of American cutaneous leishmaniasis and represented 93.8% of all phlebotomines captured with 10 Falcão light traps. The monthly densities of these insects were obtained from one Falcão light trap installed in a henhouse and increased especially in the warmer and more humid months. In the forest environment the phlebotomines were captured principally in traps installed about 10 meters above the ground and P. whitmani, B. migonei, P. intermedius, Brumptomyia brumpti, Psychodopygus monticola and P. pessoai were the dominant species. The need for information about the epidemiology of American cutaneous leishmaniasis calls for further investigation with a view to clarifying the implications of the relationship between the phlebotomines and domestic animals in the Leishmania cycle of transmission in domiciliary areas.

[Phlebotomines in an area of transmission of tegumentar leishmaniasis in the northern region of Parana State, Brazil: seasonal variation and nocturnal activity]

In two years of phlebotomine captures in a modified forest an appreciable decrease in the size of this insect population has been observed when compared to previous data from the same locality. The captures with the Shannon light trap were made in the outlying forest of Palmital farm in Terra Boa county, Parana State, Brazil. The predominant species were Lutzomyia withmani, Lutzomyia migonei, Lutzomyia intermedius e Lutzomyia fischeri. These insects were active from 6 p.m. to 6 a.m. and the period of greatest activity varied according to the species. These species' densities were higher in the summer and autumn months. Environmental modifications may have influenced the observed changes in phlebotomine behavior.

[Adult culicidae captured in the southern region of Brazil]

During the period from September 1988 to April 1990, mosquitoes were captured using Shannon light trap and Falcão light traps, in Terra Boa county, in the north of Paraná State, Brazil. The Shannon trap was installed in the outlying modified forest and Falcão traps were installed in the modified forest and domiciliary areas. The prevalence of species was verified and the methods of capture compared.

[American cutaneous leishmaniasis: phlebotominae of the area of transmission in the north of Paraná, Brazil]

Most of the cases of cutaneous leishmaniasis diagnosed in the laboratory of the State University of Maringá, Paraná, Brazil, are related to areas of northern Paraná State, which have been settled since 40 years age, when the destructions of vast areas of forest in this region was begun. The native vegetation, already, in large part, destroyed is constituted of dense forest of the type found in the transition from tropical to subtropical regions. The landscape is constituted of plateau with a climate of transition from tropical to subtropical and annual mean temperatures of 20 degrees C to 22 degrees C, the mean of the hottest month being superior to 22 degrees C. The native forests are represented by small, sparse patches of vegetation, with some modification in the basins of the rivers Ivaí, Paranapanema and Paraná and their tributaries. In this environment 24 captures of phlebotomines were made--2 per month from October 1986 to September 1987, between 6 P.M. and 1 A.M. The captures with Shannon trap were made in the outlying forest of Palmital farm. The majority of the 16,496 phlebotomines were classified into 13 species. Lutzomyia whitmani was predominant with 11,188 (67.82%) specimens, followed by Lutzomyia intermedia with 2,900 (17.58%) and Lutzomyia migonei with 1,481 (9.03%). Lutzomyia whitmani and Lutzomyia intermedia have been manifesting great capacity of adaptation in modified environments, where they have played a significant role in transmission of leishmaniasis.