Showing papers by "University of Costa Rica published in 1996"

Genetic mapping using haplotype, association and linkage methods suggests a locus for severe bipolar disorder (BPI) at 18q22-q23

Abstract: Manic-depressive illness, or bipolar disorder (BP), is characterized by episodes of elevated mood (mania) and depression1. We designed a multistage study in the genetically isolated population of the Central Valley of Costa Rica2,3 to identify genes that promote susceptibility to severe BP (termed BPI), and screened the genome of two Costa Rican BPI pedigrees (Mclnnes et al., submitted). We considered only individuals who full-filled very stringent diagnostic criteria for BPI to be affected. The strongest evidence for a BPI locus was observed in 18q22-q23. We tested 16 additional markers in this region and seven yielded peak lod scores over 1.0. These suggestive lod scores were obtained over a far greater chromosomal length (about 40 cM) than in any other genome region. This localization is supported by marker haplotypes shared by 23 of 26 BPI affected individuals studied. Additionally, marker allele frequencies over portions of this region are significantly different in the patient sample from those of the general Costa Rican population. Finally, we performed an analysis which made use of both the evidence for linkage and for association in 18q23, and we observed significant lod scores for two markers in this region.

Cognitive Correlates of Long-term Cannabis Use in Costa Rican Men

Abstract: Background: Cognitive correlates of long-term cannabis use have been elusive. We tested the hypothesis that long-term cannabis use is associated with deficits in shortterm memory, working memory, and attention in a literate, westernized culture (Costa Rica) in which the effects of cannabis use can be isolated. Methods: Two cohorts of long-term cannabis users and nonusers were studied. Within each cohort, users and nonusers were comparable in age and socioeconomic status. Polydrug users and users who tested positive for the use of cannabis at the time of cognitive assessment after a 72-hour abstention period were excluded. The older cohort (whose age was ~45 years) had consumed cannabis for an average of 34 years, and comprised 17 users and 30 nonusers, who had been recruited in San Jose, Costa Rica, and had been observed since 1973. The younger cohort (whose age was ~28 years) had consumed cannabis for an average of 8 years, and comprised 37 users and 49 nonusers. Short-term memory, working memory, and attentional skills were measured in each subject. Results: Older long-term users performed worse than older nonusers on 2 short-term memory tests involving learning lists of words. In addition, older long-term users performed worse than older nonusers on selective and divided attention tasks associated with working memory. No notable differences were apparent between younger users and nonusers. Conclusion: Long-term cannabis use was associated with disruption of short-term memory, working memory, and attentional skills in older long-term cannabis users.

A complete genome screen for genes predisposing to severe bipolar disorder in two Costa Rican pedigrees

Abstract: Bipolar mood disorder (BP) is a debilitating syndrome characterized by episodes of mania and depression. We designed a multistage study to detect all major loci predisposing to severe BP (termed BP-I) in two pedigrees drawn from the Central Valley of Costa Rica, where the population is largely descended from a few founders in the 16th–18th centuries. We considered only individuals with BP-I as affected and screened the genome for linkage with 473 microsatellite markers. We used a model for linkage analysis that incorporated a high phenocopy rate and a conservative estimate of penetrance. Our goal in this study was not to establish definitive linkage but rather to detect all regions possibly harboring major genes for BP-I in these pedigrees. To facilitate this aim, we evaluated the degree to which markers that were informative in our data set provided coverage of each genome region; we estimate that at least 94% of the genome has been covered, at a predesignated threshold determined through prior linkage simulation analyses. We report here the results of our genome screen for BP-I loci and indicate several regions that merit further study, including segments in 18q, 18p, and 11p, in which suggestive lod scores were observed for two or more contiguous markers. Isolated lod scores that exceeded our thresholds in one or both families also occurred on chromosomes 1, 2, 3, 4, 5, 7, 13, 15, 16, and 17. Interesting regions highlighted in this genome screen will be followed up using linkage disequilibrium (LD) methods.

Brucella-Salmonella lipopolysaccharide chimeras are less permeable to hydrophobic probes and more sensitive to cationic peptides and EDTA than are their native Brucella sp. counterparts.

Abstract: A rough (R) Brucella abortus 45/20 mutant was more sensitive to the bactericidal activity of polymyxin B and lactoferricin B than was its smooth (S) counterpart but considerably more resistant than Salmonella montevideo. The outer membrane (OM) and isolated lipopolysaccharide (LPS) of S. montevideo showed a higher affinity for these cationic peptides than did the corresponding B. abortus OM and LPS. We took advantage of the moderate sensitivity of R B. abortus to cationic peptides to construct live R B. abortus-S-LPS chimeras to test the activities of polymyxin B, lactoferricin B, and EDTA. Homogeneous and abundant peripheral distribution of the heterologous S-LPS was observed on the surface of the chimeras, and this coating had no effect on the viability or morphology of the cells. When the heterologous LPS corresponded to the less sensitive bacterium S B. abortus S19, the chimeras were more resistant to cationic peptides; in contrast, when the S-LPS was from the more sensitive bacterium S. montevideo, the chimeras were more susceptible to the action of peptides and EDTA. A direct correlation between the amount of heterologous S-LPS on the surface of chimeric Brucella cells and peptide sensitivity was observed. Whereas the damage produced by polymyxin B in S. montevideo and B. abortus-S. montevideo S-LPS chimeras was manifested mainly as OM blebbing and inner membrane rolling, lactoferricin B caused inner membrane detachment, vacuolization, and the formation of internal electron-dense granules in these cells. Native S and R B. abortus strains were permeable to the hydrophobic probe N-phenyl-1-naphthylamine (NPN). In contrast, only reduced amounts of NPN partitioned into the OMs of the S. montevideo and B. abortus-S. montevideo S-LPS chimeras. Following peptide exposure, accelerated NPN uptake similar to that observed for S. montevideo was detected for the B. abortus-S. montevideo LPS chimeras. The partition of NPN into native or EDTA-, polymyxin B-, or lactoferricin B-treated LPS micelles of S. montevideo or B. abortus mimicked the effects observed with intact cells, and this was confirmed by using micelle hybrids of B. abortus and S. montevideo LPSs. The results showed that LPS is the main cause of B. abortus' resistance to bactericidal cationic peptides, the OM-disturbing action of divalent cationic chelants, and OM permeability to hydrophobic substances. It is proposed that these three features are related to the ability of Brucella bacteria to multiply within phagocytes.

Modeling the Photosynthetic Water Oxidation Center: Chloride/Bromide Incorporation and Reversible Redox Processes in the Complexes Mn4O3X(OAc)3(dbm)3 (X ) Cl, Br) and (pyH)3(Mn4O3Cl7(OAc)3)

Abstract: Synthetic procedures are described that allow conversion of [Mn4O2(OAc)6(py)2(dbm)2] (1, dbmH = dibenzoylmethane) to [Mn4O3X(OAc)3(dbm)3] (X = Cl, 2; X = Br, 3). Treatment of 1 with NBun4Cl in CH2Cl2 or hot MeCN leads to 2 in 5−8% and 35−43% yields (based on dbm), respectively. A higher yield (∼88%) is obtained by treating 1 with 4 equiv of Me3SiCl in CH2Cl2. An analogous procedure with 4 equiv of Me3SiBr in CH2Br2 gives 3 in 55% yield. Complexes 2 and 3 are isomorphous, monoclinic space group P21/n, T = −155 °C, Z = 4. For 2, a = 13.900(3), b = 22.038(5), and c = 16.518(5) A and β = 107.80(1)°; for 3, a = 13.644(2), b = 22.190(4), and c = 16.548(3) A, and β = 106.64(1)°. The structures were solved by direct methods (MULTAN78) and refined on F to R(Rw) values of 7.85 (7.38) and 7.37 (6.89)% using 2267 and 2809 unique reflections with F > 2.33σ(F) for 2 and 3, respectively. Treatment of [Mn3O(OAc)6(py)3](ClO4) in MeCN with Me3SiCl followed by addition of H2O and acetic acid results in crystallization of (p...

Use of linkage disequilibrium approaches to map genes for bipolar disorder in the Costa Rican population

Abstract: Linkage disequilibrium (LD) analysis provides a powerful means for screening the genome to map the location of disease genes, such as those for bipolar disorder (BP). As described in this paper, the population of the Central Valley of Costa Rica, which is descended from a small number of founders, should be suitable for LD mapping; this assertion is supported by reconstruction of extended haplotypes shared by distantly related individuals in this population suffering low-frequency hearing loss (LFHL1), which has previously been mapped by linkage analysis. A sampling strategy is described for applying LD methods to map genes for BP, and clinical and demographic characteristics of an initially collected sample are discussed. This sample will provide a complement to a previously collected set of Costa Rican BP families which is under investigation using standard linkage analysis. 42 refs., 4 figs., 2 tabs.

A randomized double-blind clinical trial of two antivenoms in patients bitten by Bothrops atrox in Colombia

Abstract: A randomized double-blind clinical trial in 39 patients envenomed by Bothrops atrox in Antioquia and Choco, Colombia, was performed to compare the efficacy and safety of 2 equine-derived antivenoms prepared at Instituto Clodomiro Picado, University of Costa Rica. Twenty patients received a monovalent anti- B , atrox antivenom (group A) and 19 patients were treated with a polyvalent (Crotalinae) antivenom (group B). Both antivenoms were equally efficient in the neutralization of the most relevant signs of envenoming (haemorrhage and blood clotting time alteration). Fourteen patients (36%) presented early adverse reactions to antivenoms and no significant difference between the 2 groups was observed. Urticaria (18%) was the most frequent early adverse reaction and there was no life-threatening anaphylactic reaction. Based on clinical criteria and serum venom levels, estimated by an enzyme immunoassay, 15 patients were classified into 2 groups: mild and moderate/severe envenoming. With the antivenom doses used in this study (3, 6 and 9 vials for mild, moderate and severe envenoming, respectively), both antivenoms were equally efficient in clearing serum venom levels within the first hour of treatment, and the levels remained below the lower limit of venom detection for 24 h. Antivenom concentration in serum remained high for up to 24 h after antivenom infusion, suggesting that an excess of antibody in relation to circulating antigen had been administered.

Reef coral reproduction in the eastern Pacific: Costa Rica, Panamá, and Galápagos Islands (Ecuador). III. Agariciidae ( Pavona gigantea and Gardineroseris planulata )

Abstract: The reproductive ecology of Pavona gigantea Verrill and Gardineroseris planulata (Dana) was investigated in the equatorial eastern Pacific region from 1985 to 1994. These zooxanthellate scleractinian corals were adversely affected in this region during the 1982–1983 El Nino warming event. Both species were hermaphroditic, with individual colonies showing sequential cosexual development, thus resulting in dominantly outbreeding reproduction. Sexuality was mixed, with high percentages of gonochoric and hermaphroditic colonies in both species. Approximately 1:1 male-to-female gonad ratios were found in gonochoric and hermaphroditic colonies combined. Broadcast spawning was observed in P. gigantea in the Galapagos Islands, and the sudden disappearance of mature gametes and the presence of spent gonads suggest that G. planulata is also a broadcast spawner. Colonies of both species with ≲200 cm2 (10 cm diam) live tissue were nonreproductive. Estimated ages of the youngest reproductive colonies were 11 yr for P. gigantea and 20 yr for G. planulata. The percentage of all colonies of P. gigantea with gonads at nonupwelling sites (Cano Istand, Costa Rica and Uva Island, Panama) ranged from 37 to 47%, respectively; colonies with gonads from upwelling environments (Saboga and Taboga Islands, Panama) ranged from 31 to 39%, respectively, and reproductively active colonies from the thermally variable Galapagos islands comprised 40% of the collections. Compared with P. gigantea, the numbers of sexually active G. planulata colonies were roughly onehalf at nonupwelling Cano Island (20%) and Uva Island (25%) sites, or less (10%) at the upwelling Saboga Island site. Peak reproductive activity in P. gigantea occurred during the rainy season at all study sites. In the nonupwelling Costa Rican (Cano Island) and Panamainan (Uva Island) sites, mean monthly sea-surface temperatures (SSTs) were high (28 to 29°C), but slightly lower than in the dry season (29°C). In the upwelling Gulf of Panama (Saboga and Taboga Islands), reproduction occurred after mean monthly SSTs increased from 24 to 28–29°C. In the Galapagos Islands, reproductive activity peaked during sea warming, when mean monthly SSTs reached 25°C. Sexually active colonies of G. planulata, present only at the main collection sites of Cano and Uva Islands, were also observed during the wet season. The presence of mature or spawned gonalds in both species mostly around new and full lunar phases suggests that spawning is at least weakly synchronized with moon phase. Fecundity estimates disclosed the following nonsignificant differences between sites for P. gigantea, expressed as egg production cm-2 colony surface surface yr-1: Galapagos (10 300 to 30 800), Uva Island (4900 to 9800), Cano Island (1800 to 7400), Saboga Island (600 to 1300) Taboga Island (1200 to 2400). Fecundity estimates for G. planulata were considerably lower: Uva Island (700 to 1400), Cano Island (500 to 1000). The sexual recruitment of P. gigantea into El Nino-Southern Oscillation (ENSO) 1982–1983-disturbed, equatorial eastern Pacific coral communities has been low, with only moderate recovery evident since 1983. G. planulata has revealed no sexual recruitment where seed populations are absent or rare (Cano Island, Galapagos Islands), and only low recruitment (Panama) in areas with colonies that survived the ENSO disturbance.

Chlorothalonil, a possible cause of erythema dyschromicum perstans (ashy dermatitis).

Abstract: We studied 39 patients with erythema-dyschromicum-perstans-like dermatitis seen at Changuinola Hospital in Panama. They were compared with 41 controls. The 2 groups were native field workers of the banana plantations exposed to many pesticides. In 34 patients, there was a positive patch test reaction to 2,4,5,6-1,3-tetrachloroisophthalonilnitrile (chlorothalonil, TCPN) 0.001% in acetone. In 39 cases, biopsies showed a lichenoid tissue reaction compatible with a chronic pigmented dermatitis or erythema-dyschromicum-perstans-like dermatitis. Chlorothalonil is possibly the cause of the pigmented dermatitis observed in the 39 banana farm workers studied. Until additional studies are carried out, we consider this a possible rather than definite cause-and-effect relationship.

Presence of various pathogenic microorganisms in fresh vegetables in Costa Rica

Abstract: This study reports the occurrence of some pathogenic microorganisms in vegetable consumed on a daily basis by Costa Ricans. Cryptosporidium sp. oocysts were found in 5.2% (4/80) of cilantro leaves, in 8.7% (7/80) of cilantro roots and 2.5% of lettuce samples. A 1.2% (1/80) incidence was found in other vegetables samples (carrot, cucumber, radish and tomatoe). Oocysts of this parasite were absent in cabbage. Giardia intestinalis was only detected in 5.2% (4/80) of cilantro leaves and in 2.5% (2/ 80) of cilantro roots. Entamoeba histolytica cysts were found in 6.2% (5/80) of cilantro leaves, in 2.5% (2/80) cilantro roots, in 3.8% (3/80) lettuce and in 2.5% (2/80) radish samples. At least a 2% incidence of this amoeba was found in other vegetable samples (carrot, cucumber, cabbage and tomatoe). Listeria monocytogenes was isolated in 20% (10/50) of the samples of cabbage salad. Hepatitis A virus and Rotavirus were evidenciated in three of the lettuce pooles, suggesting that at least three of the samples were contaminated with these viruses.

Dispersion of human Y chromosome haplotypes based on five microsatellites in global populations.

Abstract: We have analyzed five microsatellite loci from the nonrecombining portion of the human Y chromosome in 15 diverse human populations to evaluate their usefulness in the reconstruction of human evolution and early male migrations. The results show that, in general, most populations have the same set of the most frequent alleles at these loci. Hypothetical ancestral haplotypes, reconstructed on the basis of these alleles and their close derivatives, are shared by multiple populations across racial and geographical boundaries. A network of the observed haplotypes is characterized by a lack of clustering of geographically proximal populations. In spite of this, few distinct clusters of closely related populations emerged in the network, which are associated with population-specific alleles. A tree based on allele frequencies also shows similar results. Lack of haplotypic structure associated with the presumed ancestral haplotypes consisting of individuals from almost all populations indicate a recent common ancestry and/or extensive male migration during human evolutionary history. The convergent nature of microsatellite mutation confounds population relationships. Optimum resolution of Y chromosome evolution will require the use of additional microsatellite loci and diallelic genetic markers with lower mutation rates.

An approach to investigating linkage for bipolar disorder using large Costa Rican pedigrees

Abstract: Despite the evidence that major gene effects exist for bipolar disorder (BP), efforts to map BP loci have so far been unsuccessful. A strategy for mapping BP loci is described, focused on investigation of large pedigrees from a genetically homogenous population, that of Costa Rica. This approach is based on the use of a conservative definition of the BP phenotype in preparation for whole genome screening with polymorphic markers. Linkage simulation analyses are utilized to indicate the probability of detecting evidence suggestive of linkage, using these pedigrees. These analyses are performed under a series of single locus models, ranging form recessive to nearly dominant, utilizing both lod score and affected pedigree member analyses. Additional calculations demonstrate that with any of the models employed, most of the information for linkage derives from affected rather than unaffected individuals. 26 refs., 2 figs., 5 tabs.

Distribution and evolution of CTG repeats at the myotonin protein kinase gene in human populations.

Abstract: We have analyzed the CTG repeat length and the neighboring Alu insertion/deletion (+/-) polymorphism in DNA samples from 16 ethnically and geographically diverse human populations to understand the evolutionary dynamics of the myotonic dystrophy-associated CTG repeat. Our results show that the CTG repeat length is variable in human populations. Although the (CTG)5 repeat is the most common allele in the majority of populations, this allele is absent among Costa Ricans and New Guinea highlanders. We have detected a (CTG)4 repeat allele, the smallest CTG known allele, in an American Samoan individual. (CTG) > or = 19 alleles are the most frequent in Europeans followed by the populations of Asian origin and are absent or rare in Africans. To understand the evolution of CTG repeats, we have used haplotype data from the CTG repeat and Alu(+/-) locus. Our results are consistent with previous studies, which show that among individuals of Caucasian and Japanese origin, the association of the Alu(+) allele with CTG repeats of 5 and > or = 19 is complete, whereas the Alu(-) allele is associated with (CTG)11-16 repeats. However, these associations are not exclusive in non-Caucasian populations. Most significantly, we have detected the (CTG)5 repeat allele on an Alu(-) background in several populations including Native Africans. As no (CTG)5 repeat allele on an Alu(-) background was observed thus far, it was proposed that the Alu(-) allele arose on a (CTG)11-13 background. Our data now suggest that the most parsimonious evolutionary model is (1) (CTG)5-Alu(+) is the ancestral haplotype; (2) (CTG)5-Alu(-) arose from a (CTG)5-Alu(+) chromosome later in evolution; and (3) expansion of CTG alleles occurred from (CTG)5 alleles on both Alu(+) and Alu(-) backgrounds.

Characterization of alpha-neurotoxin and phospholipase A2 activities from Micrurus venoms. Determination of the amino acid sequence and receptor-binding ability of the major alpha-neurotoxin from Micrurus nigrocinctus nigrocinctus.

Abstract: New World elapids are coral snakes that belong to the genus Micrurus, and for which the venom biochemistry is mostly unknown. Analysis has been difficult because the coral snakes produce small quantities of venom. Clinical observations following bites show mainly neurotoxic effects. Experimentally, cardiotoxic, haemolytic and myotoxic activities are also reported. An experimental approach, using reverse-phase high-performance liquid chromatography and specific assays for α-neurotoxin and phospholipase A2 activities, was conducted on milligram quantities of venoms from three Micrurus species from Costa Rica; M. nigrocinctus nigrocinctus, M. alleni yatesi and M. multifasciatus. Neurotoxicity was determined by competition binding experiments with the Torpedo marmorata acetylcholine receptor. Phospholipase A2 activity was measured by fluorimetry using a pyrene lipid substrate. In this way, we purified and characterized seven α-neurotoxins, five phospholipases A2 and four toxin homologs. The amino acid sequence of the major α-neurotoxin from M. nigrocinctus nigrocinctus venom was fully determined and compared to Old Word representatives. Distance matrix data were generated to set up phylogeny relationships among elapid short-chain α-neurotoxins, which proved to be in accordance with the taxonomic classification and geographical distribution of snake species.

Synthesis and Structural Studies of Platinum Complexes Containing Monodentate, Bridging, and Chelating Formamidine Ligands.

Abstract: The reactions of K2PtCl4 with N,N‘-diphenylformamidine (HDPhF) and N,N‘-di-p-tolylformamidine (HDTolF) produce the trans square-planar compounds PtCl2(HDPhF)2, 1a, and PtCl2(HDTolF)2, 1b. Compound 1a crystallizes as yellow parallelepipeds in the space group P21/c with two independent molecules in the asymmetric unit and unit cell dimensions a = 23.427(7) A, b = 16.677(6) A, c = 12.980(4) A, and β = 96.10(2)°. These compounds are soluble in common organic solvents and have been used as starting materials for the preparation of diplatinum compounds. Treatment of 1a and 1b with NaOMe and the halide abstraction reagent TlPF6 produces the compounds Pt2(μ-DArF)2(η2-DArF)2, Ar = Ph (2a) and Tol (2b), respectively. Compound 2a crystallizes as yellow rods in the space group P1 with unit cell dimensions a = 12.296(3) A, b = 12.310(4) A, c = 15.374(4) A, α = 90.75(2)°, β = 91.02(2)°, and γ = 110.20(2)°. Compound 2b crystallizes with a molecule of THF, as yellow rods in the space group P21/c with a = 17.883(3) A, b ...

Fluconazole in the treatment of severe onychomycosis

Abstract: Seventy-four patients were entered into an open study of the treatment of onychomycosis using the following regimen: fluconazole, 150 mg per week for 3 to 12 months. Included in the study were healthy outpatients, men and nonpregnant women, wbo were 18 years of age or older, with mycologically proven onychomycosis caused by dermatophytes and who were referred by other physicians to a participating dermatologist. Criteria for exclusion included: previous bistory of allergy to or known sensitivity to the azole group of antimycotic agents, impaired renal or hepatic function, diabetes, impaired immune function, nail infections caused by Candida or other nondermatophytes, treatment with any topical antifungal agent in the previous 3 days or with a systemic agent within 2 months prior to the start of tbe study, or unsuccessful treatment witb systemic antifungal drugs within the previous year. All investigators were dermatologists whose patients with onychomycosis are primarily referred from general physicians. Tbe first dose was given at the investigator's office. Patients were instructed to take the medication on the same day eacb week. Follow-up visits occurred at 1, 3, and 6 months after the end of therapy. Patients were considered evaluable, if they had received therapy for at least 3 months. Patients not responding to therapy after 3 months continued to receive therapy until either a clinical cure and mycologic eradication were achieved for 2 consecutive months or therapy had been received for 12 months.

Changes in meteorological variables in coronel oviedo, paraguay, during the total solar eclipse of 3 november 1994

Abstract: Solar global radiation, air temperature, relative humidity, and wind speed were measured in Coronel Oviedo, Paraguay, within the path of totality of the eclipse of 3 November 1994. Global radiation decreased gradually as the sun was being eclipsed and became negligible during the totality, then increased to their normal values. Surface air temperature decreased significantly, about 3 ‡C, with the lowest value occurring about 7 minutes after totality. Relative humidity, because of its dependence on temperature, increased as a consequence of the temperature decrease. Surface wind speed decreased gradually during the eclipse, as a result of the cooling and stabilization of the atmosphere. Although atmospheric pressure was also measured, it was not possible to record pressure changes clearly associated to the eclipse, since the pressure sensor was only able to detect pressure variations of at least 1 hPa.

The size and composition of the hymenopteran fauna of Costa Rica

Abstract: An intensive survey of the hymenopteran fauna of Costa Rica provides an opportunity to explore the size and composition of a species-rich insect order in a large tropical region. A working estimate of the richness of the fauna is 20,000 species. This is consistent with some published estimates of the numbers of species of Hymenoptera worldwide, but at odds with suggestions that all insect species number several tens of millions. Sixty-one families of Hymenoptera have been collected in Costa Rica, and the numbers of species per unit area is more than twice that of most of the other regions for which data are available. The Costa Rican fauna has higher proportions of egg parasitoids and of eusocial species, and a lower proportion of primary phytophages than that of the British Isles.

Costaricine, a New Antiplasmodial Bisbenzylisoquinoline Alkaloid from Nectandra salicifolia Trunk Bark

Abstract: A MeOH extract of Nectandra salicifolia trunk bark, obtained during a diversity-based plant collection in a lower montane rainforest in Costa Rica, showed activity in an in vitro antiplasmodial assay measuring incorporation of [3H]-labeled hypoxanthie by Plasmodium falciparum. In addition to 15 known alkaloids isolated from samples of trunk bark, roots, and leaves/twigs of this species, a new bisbenzylisoquinoline alkaloid (+)-costaricine [(+)-12-O-methyllindoldhamine] (1) was isolated from bark (0.038% yield) and from roots (0.001%). (+)-Costaricine was active in the antiplasmodial assay, with IC50 values of 50 ng/mL vs. the chloroquine-sensitive D6 clone and 294 ng/mL vs. the chloroquine-resistant W2 clone of P. falciparum.

Chemical and biological evaluation of the effect of plant extracts against Plasmodium berghei

Abstract: Extracts from thirteen species of plants were evaluated by "in vivo" antimalarial test against plasmodium berghei effects. Significant activities were observed in the ethyl acetate and aqueous extracts, elaborated of Cedrela tonduzii leaves, Trichilia havanensis and Trichilia americana barks, Neurolaena lobata and Gliricidia sepium leaves and Duranta repens fruits. Compounds identified include flavanoids, coumarins, mellilotic acid and iridoids which some kind of biodynamic activity has previously been reported. The flavone quercetin 1 purified from C. tonduzii gave strong antimalarial activity, however, its respective glucosides (quercetin 3-glucoside 2 y robinine 7) showed little significant activity.

Evidence for Gustatorial Courtship in a Haplogyne Spider (Hedypsilus Culicinus: Pholcidae: Araneae)

Abstract: Gustatorial courtship, which is so far only known from two entelegyne families among spiders, is for the first time documented in a haplogyne spider, Hedypsilus culicinus Simon, 1893 (Pholcidae). The convergence to entelegynes is explained by (1) comparable mating position, and (2) body proportions.

nido-Metalloborane Complexes: Synthesis and Structural Characterization of μ2,η4-Hexahydrodiboratotetrakis(N,N‘-diarylformamidinato)ditantalum(III), Aryl = p-Tolyl and Phenyl. The First Structurally Characterized Complexes Containing the μ2,η4-B2H62- Ligand

Abstract: The nido-metalloborane complexes Ta2(μ2,η4-B2H6)(DTolF)4·2Et2O, 1, DTolF- = [(p-tolyl)NCHN(p-tolyl)]-, and Ta2(μ2,η4-B2H6)(DPhF)4·Et2O, 2, DPhF- = [phenylNCHNphenyl]-, are formed as the products of...