Seroprevalence of Neospora caninum and Toxoplasma gondii antibodies in the South American opossum (Didelphis marsupialis) from the city of São Paulo, Brazil

Antibodies to Neospora caninum and Toxoplasma gondii were assayed in sera of 396 opossums (Didelphis marsupialis) from the city of S?o Paulo, Brazil. Antibodies to N. caninum were assayed using the indirect immunofluorescent antibody test (IFAT). Antibodies (IFAT, approximately 1:25) to N. caninum were found in 84 opossums (D. marsupialis) in titers of 1:25 in 46, 1:50 in 20, 1:100 in 17, and 1:400 in 1. Antibodies to T. gondii were assayed with the modified agglutination test (MAT) and the IFAT. Antibodies to T. gondii (MAT, approximately 1:25) were found in 82 (20.4%) of the 396 opossums, in titers of 1:25 in 24, 1:50 in 26, 1:100 in 18, 1:200 in 13, and 1:800 in 1. The IFAT antibodies to T. gondii were found in 148 of 396 opossums, in titers of 1:16 in 41, 1:32 in 23, 1:64 in 13, 1:128 in 6, 1:256 in 20, 1:512 in 17, 1:1,024 in 10, 1:2,048 in 10, 1:4,096 in 7, and 1:8,192 in 1. This is the first report of N. caninum and T. gondii infections in D. marsupialis.     

Seroprevalence of Toxoplasma gondii antibodies in cats and pigs from rural Western Amazon, Brazil

Antibodies to Toxoplasma gondii were assayed in sera of 63 cats and 80 pigs from 71 farms located at Rond?nia State, Western Amazon, Brazil, by the modified agglutination test (MAT) and the indirect immunofluorescent antibody test (IFAT). Antibodies (MAT > or = 1: 25) were found in 55 of 63 cats (87.3%) with titers of 1:25 in 2, 1:50 in 2, 1:100 in 7, 1:200 in 1, 1:400 in 2, 1:800 in 9, 1:1,600 in 6, and 1:3,200 or higher in 26 cats. By IFAT, antibodies were found in 55 cats (87.3%) with titers of 1:25 in 2, 1:50 in 1, 1:100 in 4, 1:200 in 4, 1: 400 in 1, 1:800 in 13, 1:1,600 in 12, and 1:3,200 or higher in 18 cats. In pig sera, by MAT, antibodies were found in 30 of 80 pigs (37.5%) with titers of 1:25 in 2, 1:50 in 3, 1:100 in 2, 1:200 in 8, 1:400 in 3, 1:800 in 5, 1:1,600 in 3, and 1:3,200 or higher in 4 pigs. By using the IFAT (titers > or = 1:64), antibodies were found in 35 (43.7%) pigs. The ingestion of undercooked tissues of infected pigs can be a source of T. gondii infection for humans and cats. However, the high seroprevalence of T. gondii in cats from the Amazon seems most likely to be indicative of high contamination of the environment by oocysts.     

Biochemical and serological characteristics of Escherichia belonging to the serological group 01]

A circulation at the territory of the country of various biochemical and serological variants of escherichia belonging to serological group O1, isolated in acute intestinal diseases of children and adults, was revealed. Nonhomogeneousness of the partial composition of the O-antigen was demonstrated; K-antigens were determined; new H-antigens were described. Of the 10 serological types of escherichia there proved to prevail O1 : K? : Hp and O1 : K1 : Hp; in group and sporadic acute intestinal diseases there were for the first time isolated O1 : K1 : H34, O1 : K1 : H20, O1 : K1 : Hp, O1 : K51 : H7, and O1 : K? : H20.     

HLA genetic profile of Mapuche (Araucanian) Amerindians from Chile

Amerindian Mapuche (Araucanians) are now living in Chile and Argentina at both sides of Andean Mountains. They are anthropologically and genetically different from southernmost South America Patagonian Amerindians. Most of the HLA alleles found in our Mapuche sample are frequent or very frequent in North and South America Amerindians: (1) Class I: A*02:01, A*03:01, A*68:01, B*39:09, B*51:01, (2) Class II: DRB1*03:01, DRB1*04:03, DRB1*07:01, DRB1*08:02, DRB1*14:02, DRB1*16:02. One of the nine most frequent extended haplotypes seems to be from European origin, suggesting the existence of a degree of admixture with Europeans in our Mapuche sample. It has been calculated of about 11 % admixture. Three of the extended haplotypes are also found in other Amerindians and five of them are newly found in Mapuche Amerindians: A*68:01-B*39:09-DRB1*08:02-DQB1*04:02; A*68:01-B*51:01-DRB1*04:03-DQB1*03:02; A*29:01-B*08:01-DRB1*03:01-DQB1*02:01; A*02:01-B*15:01-DRB1*04:03-DQB1*03:02; A*33:01-B*14:02-DRB1*07:01-DQB1*03:03. The medical importance of calculating HLA profile is discussed on the diagnostic (HLA and disease) and therapeutical bases of HLA pharmacogenomics and on the construction of a virtual transplantation HLA list profile. Also, anthropological conclusions are drawn.     

A comparison of several serologic tests to detect antibodies to Toxoplasma gondii in naturally exposed bottlenose dolphins (Tursiops truncatus)

Toxoplasma gondii infection in marine mammals is intriguing and indicative of contamination of the ocean environment and coastal waters with oocysts. In a previous study, 138 of 141 (97.8%) bottlenose dolphins (Tursiops truncatus) from the coasts of Florida and California had antibodies to T. gondii by the modified agglutination test (MAT). Although the MAT has been found to be highly sensitive and specific for T. gondii antibodies from several species of terrestrial animals, it has not yet been validated for T. gondii infections in marine mammals. Furthermore, T. gondii has yet not been isolated from dolphins. In the present study, sera from 146 (60 from the 2004 samples and 86 from the 2003 samples) T. truncatus from the coastal areas of South Carolina and Florida were tested for antibodies to T. gondii. Sera from 2004 were tested by the MAT, the indirect fluorescent antibody test (IFAT), the Sabin-Feldman dye test (DT), an indirect hemagglutination test (IHAT), an enzyme-linked immunosorbent assay (ELISA), and Western blot. All 60 dolphins were seropositive, with MAT titers of 1:20 in 3, 1:40 in 19, 1:80 in 29, 1:160 in 2, 1:1,280 in 3, 1:2,560 in 2, and 1:5,120 or higher in 2, and these results were confirmed in another laboratory. The DT titers of these dolphins were <1:10 in 53, 1:800 in 3, 1:1,600 in 2, and 1:3,200 in 2. The IHAT titers were <1:64 in 52, 1:128 in 1, 1:512 in 2, and 1:2,048 in 5. The IFAT titers were <1:20 in 3, 1:20 in 11, 1:40 in 36, 1:80 in 2, 1:160 in 1, and 1:320 or higher in 7. All 7 DT-positive dolphins had high MAT titers, but 2 were negative by the IHAT. Western blot results closely followed MAT results; ELISA results matched MAT results, which were 1:40 or higher. In sera from the 2003 samples, MAT antibodies were found in 86 of 86 dolphins with titers of 1:25 in 29, 1:50 in 23, 1:100 in 27, 1:200 in 3, 1:1,600 in 1, and 1:3,200 in 3; these sera were not tested by other means. Overall, MAT antibodies were found in all 146 dolphin sera tested. Because marine mammals are considered sentinel animals indicative of contamination of the coastal and marine waters by T. gondii oocysts, serologically positive infections need to be validated by the detection of T. gondii organisms in the tissues of seropositive animals.     

RNAi介导的棉铃虫氨肽酶N基因Haapn1和钙粘蛋白基因Ha_BtR沉默对Cry1Ac毒力的影响

氨肽酶N（aminopeptidase N, APN）和钙粘蛋白（cadherin）是存在于鳞翅目昆虫中肠刷状缘膜囊（brush border membrane vesicles, BBMV）上Bt毒素Cry1A的受体。本实验将棉铃虫Helicoverpa armigera氨肽酶N1基因Haapn1和钙粘蛋白基因Ha_BtR双链RNA（dsRNA）注入棉铃虫4龄幼虫体内, 以研究这两种受体基因沉默后对Cry1Ac毒力的影响。结果表明: 注射dsRNA（1 μg/头）进行基因沉默后, Haapn1 mRNA表达量比注射缓冲液（elution solution, ES）的对照下降了30%~49%, Ha_BtR mRNA表达量下降了30%~37%。注射Haapn1 dsRNA的幼虫在40和70 μg/cm² Cry1Ac活化毒素下的死亡率显著低于注射ES的幼虫, 而在 100 和 170 μg/cm² Cry1Ac原毒素处理下两者死亡率无显著差异; Cry1Ac活化毒素以及原毒素对注射Ha_BtR dsRNA幼虫与注射ES幼虫的毒力均无显著差异。当同时注射Haapn1及Ha_BtR dsRNA后, 干扰后的幼虫对Cry1Ac活化毒素和原毒素的敏感性均显著下降。本研究进一步证明了棉铃虫Haapn1和Ha_BtR均是Bt毒素Cry1Ac的功能受体, 这两种受体蛋白共同参与Cry1Ac的毒杀作用过程。该结果也提示, Haapn1或Ha_BtR基因产生突变都可能导致棉铃虫对Cry1Ac产生抗性。     

Interactions of proteins with ganglioside-enriched microdomains on the membrane: the lateral phase separation of molecular species of GD1a ganglioside, having homogeneous long-chain base composition, is recognized by Vibrio cholerae sialidase

The thermotropic behavior (studied by high-sensitivity differential scanning calorimetry) and susceptibility to Vibrio cholerae sialidase hydrolysis of large unilamellar vesicles of dipalmitoyl-phosphatidylcholine, containing native GD1a ganglioside or the molecular species of GD1a containing C18:1 or C20:1 long-chain base (C18:1 GD1a; C20:1 GD1a), were studied. Vesicles containing ganglioside (10% in molar terms) showed the presence in the heat capacity function of a second minor peak besides the phospholipid main transition peak. The presence of a second peak is much more evident with C20:1 GD1a than with C18:1 GD1a, the difference being potentiated by Ca2+ and indicating a different tendency of the CD1a molecular species to undergo lateral phase separation. The scans of vesicles containing native GD1a showed the features of those obtained with C18:1 GD1a and C20:1 GD1a, indicating that the main components of native GD1a, C18:1 GD1a and C20:1 GD1a, maintain their individual aggregative properties. V. cholerae sialidase affects vesicle-bound GD1a at a much higher rate (17-25-fold) than it does micellar GD1a, the activation by Ca2+ being 3- and 2-fold, respectively. The Vmax values were identical on C18:1 GD1a and C20:1 GD1a in micellar dispersions, whereas they were markedly higher (from 20 to 50%) on C18:1 GD1a than on C20:1 GD1a in vesicular dispersions. Exhaustive sialidase hydrolysis of vesicles carrying native GD1a produced C18:1 GM1 and C20:1 GM1 in the same proportion as the C18:1 and C20:1 species present in native GD1a (53.9% and 46.1%).(ABSTRACT TRUNCATED AT 250 WORDS)     

Crystal Structure Transformations and Dissolution Studies of Cimetidine–Piroxicam Coprecipitates and Physical Mixtures

We have recently demonstrated that coprecipitation of cimetidine (C) and piroxicam (P) at a mole ratio of 1:1 results in the transformation of the crystalline forms of both drugs to an amorphous state. In this study, coprecipitates and physical mixtures of cimetidine and piroxicam were further investigated at C/P mole ratios of 1:10, 1:5, 1:4, 1:2, 10:1, 20:1, 30:1, 40:1, and 52.5:1, the latter being the composition of a clinically used dosage. The physicochemical properties of these samples were examined using X-ray diffraction and Fourier transform infrared spectroscopy. Additionally, dissolution of piroxicam in the samples at C/P mole ratios of 10:1, 20:1, 30:1, 40:1, and 52.5:1 was investigated at pH 1.2 and pH 4. In coprecipitates with C/P mole ratios of 10:1, 20:1, 30:1, and 40:1, crystalline forms of both drugs were transformed to amorphous states. A mixture of an amorphous state and cimetidine crystalline form A was observed for the coprecipitate with a C/P mole ratio of 52.5:1. For the coprecipitates with C/P mole ratios of 1:2, 1:4, 1:5, and 1:10, cimetidine form A was transformed to form C, whereas piroxicam form II was modified to form I. It is interesting that small molecules, instead of polymers or solvents, can cause such crystal structure transformations. The dissolution of piroxicam at pH 4 is lower than that at pH 1.2. Additionally, the coprecipitates and physical mixtures with C/P mole ratios of 10:1, 20:1, 30:1, 40:1, and 52.5:1 demonstrate substantially higher dissolution of piroxicam compared to that of drug alone.     

栽培介质、营养液及化学药剂对红掌生长开花的影响

采用泥炭:珍珠岩:沙(1:1:1)、珍珠岩和水3种栽培介质及3个配方的营养液对红掌进行无土栽培,结果表明,以水作为介质,营养液配方为N:P₂O₅:K₂O=4:1:8的培养液对红掌株高、叶片数及植株净重的增加效果最好,但水培对红掌开花无促进作用。以水为介质的红掌经高温(32℃)胁迫后叶片黄化数为零,显著低于其它处理组;而在泥炭:珍珠岩:沙(1:1:1)介质中,则是6-BA处理的叶片黄化数明显低于其它处理组。     

Balanced intake of protein and carbohydrate maximizes lifetime reproductive success in the mealworm beetle,Tenebrio molitor (Coleoptera: Tenebrionidae)

Recent developments in insect gerontological and nutritional research have suggested that the dietary protein:carbohydrate (P:C) balance is a critical determinant of lifespan and reproduction in many insects. However, most studies investigating this important role of dietary P:C balance have been conducted using dipteran and orthopteran species. In this study, we used the mealworm beetles, Tenebrio molitor L. (Coleoptera: Tenebrionidae), to test the effects of dietary P:C balance on lifespan and reproduction. Regardless of their reproductive status, both male and female beetles had the shortest lifespan at the protein-biased ratio of P:C 5:1. Mean lifespan was the longest at P:C 1:1 for males and at both P:C 1:1 and 1:5 for females. Mating significantly curtailed the lifespan of both males and females, indicating the survival cost of mating. Age-specific egg laying was significantly higher at P:C 1:1 than at the two imbalanced P:C ratios (1:5 or 5:1) at any given age throughout their lives, resulting in the highest lifetime reproductive success at P:C 1:1. When given a choice, beetles actively regulated their intake of protein and carbohydrate to a slightly carbohydrate-biased ratio (P:C 1:1.54–1:1.64 for males and P:C 1:1.3–1:1.36 for females). The self-selected P:C ratio was significantly higher for females than males, reflecting a higher protein requirement for egg production. Collectively, our results add to a growing body of evidence suggesting the key role played by dietary macronutrient balance in shaping lifespan and reproduction in insects.     

Some Eugregarines (Sporozoa, Apicomplexa) from the Stored Fruit Beetle, Oryzaephilus mercator Fauv. (Coleoptera) from India

Morphology and life history of 3 cephaline gregarines found in the gut of the pest of stored fruit, Oryzaephilus mercator. are described. Of these 3, 2 are new species. The 3 species are (1) Hirmocystis minuta (Ishii, 1914) (LP TL = 1:7 – 1:22, WP/WD = 1:1, 6–1:7); (2) Amsotobus indicus n. sp. (LP/TL = 1:3–1:6, WP/WD = 1:1 – 1:1.3); (3) Leidyana oryzaephili n. sp. (LP/TL = 1:2 – 1:12; WP/WD = 1:1–1:1.6).     

Positional Distribution of Acyl and Alk-1-enyl Groups in Grey and White Matter Ethanolamine and Choline Phosphoglycerides of a Marsupial, the Koala (Phascolarctos cinereus)

The major phosphoglycerides in grey and white matter from the brain of the koala have been separated and examined. The major polyunsaturated fatty acids present in both the diacyl- and alk-1-enyl acylglycerophosphorylethanolamines from grey matter were 22:6 omega 3, 20:4 omega 6, and 22:4 omega 6. In both grey and white matter, 22:6 omega 3 and 20:4 omega 6 were concentrated in the 2-position of diacylglycerophosphorylethanolamines and 22:4 omega 6 in the 2-position of alk-1-enylacylglycerophosphorylethanolamines; polyunsaturated fatty acid levels were higher in diacylglycerophosphorylethanolamines. Ethanolamine phosphoglyceride fractions from grey matter were enriched in polyunsaturated fatty acids compared with those from white matter. The acyl groups 18:0, 18:1, and 16:0 and their alk-1-enyl analogues were prominent in grey and white matter ethanolamine phosphoglycerides; 18:1 was dominant in white matter alk-1-enylacylglycerophosphorylethanolamines. The plasmalogen composition of ethanolamine phosphoglycerides was 55% in grey matter and 76% in white matter. Choline phosphoglycerides contained negligible plasmalogen and low polyunsaturated fatty acid levels. Diacylglycerophosphorylcholine was characterized by high levels of 16:0 and 18:1. Similar acyl group distributions were estimated in the 1-position in both grey and white matter, 16:0 being present at greater than 50%. The presence of the molecular species 18:0/22:6 omega 3 was indicated in grey matter diacylglycerophosphorylethanolamine, 18:1/18:1 in white matter alk-1-enylcylglycerophosphorylethanolamine, and 16:0/18:1 in white matter diacylglycerophosphorylcholine.     

Dietary protein:carbohydrate balance is a critical modulator of lifespan and reproduction in Drosophila melanogaster: A test using a chemically defined diet

Macronutrient balance is an important determinant of fitness in many animals, including insects. Previous studies have shown that altering the concentrations of yeast and sugar in the semi-synthetic media has a profound impact on lifespan in Drosophila melanogaster, suggesting that dietary protein:carbohydrate (P:C) balance is the main driver of lifespan and ageing processes. However, since yeast is rich in multiple nutrients other than proteins, this lifespan-determining role of dietary P:C balance needs to be further substantiated through trials using a chemically-defined, synthetic diet. In the present study, the effects of dietary P:C balance on lifespan and fecundity were investigated in female D. melanogaster flies fed on one of eight isocaloric synthetic diets differing in P:C ratio (0:1, 1:16, 1:8, 1:4, 1:2, 1:1, 2:1 or 4:1). Lifespan and dietary P:C ratio were related in a convex manner, with lifespan increasing to a peak at the two intermediate P:C ratios (1:2 and 1:4) and falling at the imbalanced ratios (0:1 and 4:1). Ingesting nutritionally imbalanced diets not only caused an earlier onset of senescence but also accelerated the age-dependent increase in mortality. Egg production was suppressed when flies were fed on a protein-deficient food (0:1), but increased with increasing dietary P:C ratio. Long-lived flies at the intermediate P:C ratios (1:2 and 1:4) stored a greater amount of lipids than those short-lived ones at the two imbalanced ratios (0:1 and 4:1). These findings provide a strong support to the notion that adequate dietary P:C balance is crucial for extending lifespan in D. melanogaster and offer new insights into how dietary P:C balance affects lifespan and ageing through its impacts on body composition.     

Isolation, tissue distribution, and molecular characterization of Toxoplasma gondii from free-range chickens from Guatemala

The prevalence of Toxoplasma gondii in free-ranging chickens is a good indicator of the prevalence of T. gondii oocysts in the soil because chickens feed from the ground. The prevalence of T. gondii in 50 free-range chickens (Gallus domesticus) from Guatemala was determined. Antibodies to T. gondii were assayed by the modified agglutination test (MAT). Antibodies were found in 37 (74%) chickens with titers of 1:5 (11), 1:10 (7), 1:20 (11), 1:40 (1), 1:80 (1), 1:160 (3), 1:1,280 (2), and 1:2,560 (1). Hearts, pectoral muscles, and brains of 19 chickens with MAT titers of 1:20 or more were bioassayed individually in mice. Tissues from the remaining 31 chickens with titers of 1:10 or lower were pooled and fed to 4 T. gondii-free cats (13 chickens with titers of less than 1:5 to 1 cat, 11 chickens with titers of 1:5 to 2 cats, and 7 chickens with titers of 1:10 to 1 cat). Feces of cats were examined for oocysts; they did not shed oocysts. Toxoplasma gondii was isolated from 8 chickens with MAT titers of 1:20 or more (from 1 of 11 chickens with a titer of 1:20 and all 7 chickens with a titer of 1:80 or more) from the heart, brain, and pectoral muscle (3); heart and pectoral muscle (1); and heart alone (4). Genotyping of these 8 isolates with the SAG2 locus indicated that 5 were type III and 3 were type 1. This is the first report of isolation of T. gondii from chickens from Guatemala.     

Existence of endogenous inhibitors of platelet-activating factor (PAF) with PAF in rat uterus

Two kinds of phospholipids in normal rat uterus were found to inhibit the aggregation of washed rabbit platelets induced by 1-alkyl-2-acetyl-sn-glycero-3-phosphocholine (alkylacetyl-GPC) and were named Inhibitor I and Inhibitor II and identified by mass spectrometry. Inhibitor I was a mixture of 1-acyl (16:0, 18:0, 18:1, 18:2, and 20:4)-2-lyso-sn-glycero-3-phosphocholine (acyllyso-GPC) and 1-alkyl (16:0, 18:0, and 18:1)-2-lyso-sn-glycero-3-phosphocholine (alkyllyso-GPC). 16:0 acyllyso-GPC was the most inhibitory, followed by 18:1, 18:2, 20:4, and 18:0 acyllyso-GPCs and 16:0 alkyllyso-GPC. Their IC50 values were in the range of 1-4 X 10(-5) M against the platelet aggregation induced by 1 X 10(-10) M 16:0 alkylacetyl-GPC, indicating that they were about 100 times weaker inhibitors than CV-3988. Inhibitor II was a mixture of N-acyl sphing-4-enyl phosphocholine (18:1/18:0, 18:1/20:0, 18:1/24:0, and 18:1/24:2). The most inhibitory of these components were 18:1/20:0 and 18:1/24:0, followed by 18:1/24:2 and 18:1/18:0, and their IC50 values were in the range of 4-5 X 10(-5) M against platelet aggregation induced by the alkylacetyl-GPC. Quantitatively, about 10(5) times higher concentrations of these inhibitors should be necessary to inhibit platelet aggregation induced by 1 X 10(-10) M 16:0 alkylacetyl-GPC. In fact, the contents of Inhibitors I and II, respectively, were approximately 10(5) times (4.7 X 10(-2) and 7.1 X 10(-2) mol/mol lipid-phosphorus of the original uterine phospholipids) than that of 16:0 alkylacetyl-GPC (1.4 X 10(-6) mol/mol lipid-phosphorus). The role of alkylacetyl-GPC in normal rat uterus is uncertain, but it coexists in situ with two kinds of endogenous inhibitors, choline containing lysoglycerophospholipids and sphingophospholipids.     

Partitioning of a fluorescent phospholipid between fluid bilayers: dependence on host lipid acyl chains

The partition coefficient Kp was measured for a headgroup-labeled phospholipid (12:0,12:0)-N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)-PE (12-NBD-PE), equilibrated between LUV of a series of phosphatidylcholines (PC). Fluorescence resonance energy transfer between the 12-NBD-PE and a headgroup-rhodamine-labeled PE was used to find the equilibrium concentration of the 12-NBD-PE in the different LUV. Reliable equilibrium concentrations were obtained by monitoring the approach to equilibrium starting from a concentration below and from a concentration above the ultimate values. Using (16:0,18:1delta9)-PC as the reference lipid, Kp ranged from a high value of 1.65 favoring (16:0,18:1delta9)-PC over (16:1delta9,16:1delta9)-PC, to a low value of 0.90, favoring (22:1delta13,22:1delta13)-PC over (16:0,18:1delta9)-PC. The Kp values enabled calculation of the acyl chain contribution to the excess free energy of mixing for (12:0,12:0) acyl chains at infinite dilution in the L alpha phase of PC having acyl chains of (16:0,18:1delta9), (16:1delta9,16:1delta9), (18:1delta9,18:1delta9), (18:1delta6,18:1delta6), (20:1delta11,20:1delta11), and (22:1delta13,22:1delta13). (14:1delta9,14:1delta9)-PC was found to transfer so rapidly between LUV as to preclude reliable Kp measurement.