Dependence between Cu concentration in the liver,kidneys and skeletal muscles of canine females

The aim of the investigations was the determination of the Cu contents in the liver, kidneys and skeletal muscles of canine females. Material for research was collected post mortem from 45 animals aged 1 to 18 years coming from the Warsaw area. The effect of the health state, age and life conditions on the distribution of copper in the investigated organs was estimated. That element was determined using the method of inductively coupled plasma-atomic emission spectrometry (ICP-AES). In the liver, the average Cu contents amounted to 24.04 mg kg⁻¹ wet weight, in kidneys to 2.90 mg kg⁻¹ wet weight and in muscles to 0.94 mg kg⁻¹ wet weight. The highest values of copper content in particular tissues and organs were noted in the group of animals with neoplastic changes. In respect to the animal age the highest mean values of the copper content were noted in the oldest animals. They amounted to 30.97 mg kg⁻¹ in the liver, 3.34 mg kg⁻¹ in kidneys and 1.18 mg kg⁻¹ wet weight in muscles. Considering life conditions of the dogs it was observed that the higher mean values in all the investigated organs occurred in dogs coming from the urban areas.     

Spatial dimensions of dengue virus transmission across interepidemic and epidemic periods in Iquitos, Peru (1999-2003)

Background

Knowledge of spatial patterns of dengue virus (DENV) infection is important for understanding transmission dynamics and guiding effective disease prevention strategies. Because movement of infected humans and mosquito vectors plays a role in the spread and persistence of virus, spatial dimensions of transmission can range from small household foci to large community clusters. Current understanding is limited because past analyses emphasized clinically apparent illness and did not account for the potentially large proportion of inapparent infections. In this study we analyzed both clinically apparent and overall infections to determine the extent of clustering among human DENV infections.

Methodology/Principal Findings

We conducted spatial analyses at global and local scales, using acute case and seroconversion data from a prospective longitudinal cohort in Iquitos, Peru, from 1999–2003. Our study began during a period of interepidemic DENV-1 and DENV-2 transmission and transitioned to epidemic DENV-3 transmission. Infection status was determined by seroconversion based on plaque neutralization testing of sequential blood samples taken at approximately six-month intervals, with date of infection assigned as the middate between paired samples. Each year was divided into three distinct seasonal periods of DENV transmission. Spatial heterogeneity was detected in baseline seroprevalence for DENV-1 and DENV-2. Cumulative DENV-3 seroprevalence calculated by trimester from 2001–2003 was spatially similar to preexisting DENV-1 and DENV-2 seroprevalence. Global clustering (case-control Ripley''s K statistic) appeared at radii of ∼200–800 m. Local analyses (Kuldorf spatial scan statistic) identified eight DENV-1 and 15 DENV-3 clusters from 1999–2003. The number of seroconversions per cluster ranged from 3–34 with radii from zero (a single household) to 750 m; 65% of clusters had radii >100 m. No clustering was detected among clinically apparent infections.

Conclusions/Significance

Seroprevalence of previously circulating DENV serotypes can be a predictor of transmission risk for a different invading serotype and, thus, identify targets for strategically placed surveillance and intervention. Seroprevalence of a specific serotype is also important, but does not preclude other contributing factors, such as mosquito density, in determining where transmission of that virus will occur. Regardless of the epidemiological context or virus serotype, human movement appears to be an important factor in defining the spatial dimensions of DENV transmission and, thus, should be considered in the design and evaluation of surveillance and intervention strategies.     

A revision of the New World species of Gymnoclasiopa Hendel (Diptera,Ephydridae)

Species of the shore-fly genus Gymnoclasiopa Hendel from the New World are revised, including Gymnoclasiopa grecorum sp. n. (Alaska. Juneau: Gastineau Channel, Thane Road (S Juneau; 58°16.9''N, 134°22.4''W)) and Gymnoclasiopa matanuska sp. n. (Alaska. Matanuska-Susitna: Palmer (Matanuska River; 61°36.5''N, 149°04.1''W)). We also clarify the status of previously described species, including those now discovered to have Holarctic distributions and/or for which sexual dimorphism was not appreciated and the species was described twice, including Gymnoclasiopa montana (Cresson) as a syn. n. of Gymnoclasiopa bohemanni (Becker). Two species, Gymnoclasiopa bella (Mathis), comb. n., and Gymnoclasiopa chiapas (Mathis), comb. n., are transferred from Ditrichophora to Gymnoclasiopa, and Gymnoclasiopa cana Cresson stat. rev. and Ditrichophora canifrons Cresson, stat. rev. are returned to Ditrichophora, the genus in which Cresson originally described them. A neotype is designated for Gymnoclasiopa tacoma to stabilize the nomenclature of this species. The two excluded species, Ditrichophora cana and Ditrichophora canifrons, are diagnosed and distributional data are also provided. For all known New World species of Gymnoclasiopa, structures of the male terminalia are described for the first time and are fully illustrated. Detailed locality data and distribution maps are also included. To provide context and also to facilitate identification, diagnoses are included for the tribe Discocerinini and genus in addition to a key to the genera and species occurring in the New World.     

Revision of New World Species of the Shore-fly Subgenus Allotrichoma Becker of the Genus Allotrichoma with Description of the Subgenus Neotrichoma (Diptera, Ephydridae, Hecamedini)

The New World species of the subgenera Allotrichoma Becker and Neotrichoma (new subgenus) are revised, including a phylogenetic analysis of the species groups and subgenera within the genus Allotrichoma. For phylogenetic perspective and to document the monophyly of the genus Allotrichoma and its included subgenera and species groups, we also provide a cladistic analysis of genera within the tribe Hecamedini. The ingroup included seven exemplar congeners from within Allotrichoma. Outgroup sampling included exemplars of other genera within Hecamedini and from the putative sister group, Lipochaetini, and to root the analysis, we used an exemplar of the tribe Discocerinini. Analyses with successive weighting and implied weighting recovered a monophyletic Allotrichoma and indicated clades within the genus. Eight new species are described (type locality in parenthesis): Allotrichoma bifurcatum (Utah. Utah: Lake Shore (40°06.9'N, 111°41.8'W; 1370 m)), Allotrichoma dynatum (Oregon. Benton: Finley National Wildlife Refuge (44°24.6'N, 123°19.5'W)), Allotrichoma occidentale (Oregon. Lake: Lakeview (44 km E; Drake Creek; 42°11'N, 119°59.3'W)), Allotrichoma robustum (California. Kern: Kern River (35°16.1'N, 119°18.4'W)), Allotrichoma sabroskyi (New Mexico. Sandoval: La Cueva (Junction of Highways 126 and 4; 35°52'N, 106°38.4'W; 2342 m)), Allotrichoma wallowa (Oregon Baker: Goose Creek (35 km E Baker City; 44°49.2'N, 117°27.79'W; 825 m)), Allotrichoma baliops (Florida. Monroe: Key West (Willie Ward Park; 24°32.9'N, 81°47.9'W)), and Allotrichoma insulare (Dominica. Cabrits Swamp (15°35'N, 61°29'W)). Within Allotrichoma, we recognize three subgenera of which one, Neotrichoma (type species: Allotrichoma atrilabre), is newly described. All known species from the New World are described with an emphasis on structures of the male terminalia, which are fully illustrated. Detailed locality data and distribution maps for the New World species are provided. A lectotype is designated for Discocerina simplex Loew and a neotype is designated for Allotrichoma bezzii Becker. Allotrichoma filiforme Becker, Allotrichoma trispinum Becker, and Allotrichoma dahli Beschovski are reported as new synonyms of Allotrichoma simplex (Loew) and Allotrichoma yosemite Cresson is a new synonym of Allotrichoma atrilabre Cresson. We also clarify the status of previously described species, including those with Holarctic distributions. For perspective and to facilitate genus-group and species-group recognition, the tribe Hecamedini is diagnosed and a key to included genera is provided.     

Neuromelanin can protect against iron-mediated oxidative damage in system modeling iron overload of brain aging and Parkinson's disease

In Parkinson's disease (PD), dopamine neurons containing neuromelanin selectively degenerate. Neuromelanin binds iron and accumulates in aging. Iron accumulates in reactive form during aging, PD, and is involved in neurodegeneration. It is not clear how the interaction of neuromelanin and iron can be protective or toxic by modulating redox processes. Here, we investigated the interaction of neuromelanin from human substantia nigra with iron in the presence of ascorbic acid, dopamine, and hydrogen peroxide. We observed that neuromelanin blocks hydroxyl radical production by Fenton's reaction, in a dose-dependent manner. Neuromelanin also inhibited the iron-mediated oxidation of ascorbic acid, thus sparing this major antioxidant molecule in brain. The protective effect of neuromelanin on ascorbate oxidation occurs even in conditions of iron overload into neuromelanin. The blockade of iron into a stable iron–neuromelanin complex prevents dopamine oxidation, inhibiting the formation of neurotoxic dopamine quinones. The above processes occur intraneuronally in aging and PD, thus showing that neuromelanin is neuroprotective. The iron–neuromelanin complex is completely decomposed by hydrogen peroxide and its degradation rate increases with the amount of iron bound to neuromelanin. This occurs in PD when extraneuronal iron–neuromelanin is phagocytosed by microglia and iron–neuromelanin degradation releases reactive/toxic iron.     

Environmental stability and the distribution of the sexes: insights from life history experiments with the geographic parthenogen Eucypris virens (Crustacea: Ostracoda)

In many species with mixed reproduction, parthenogens cover a wider geographic range than sexuals. In freshwater ostracods this pattern referred to as geographic parthenogenesis is traditionally explained by ascribing a higher potential for dispersal to parthenogens. For example, the postglacial invasion hypothesis states that the lack of males in northern Europe is caused by the relatively slow range expansion of sexual lineages after deglaciation. An alternative explanation for the contemporary distribution of the sexes is based on spatial and temporal variations in ecological habitat stability. To test this hypothesis, we compared life history data of Eucypris virens individuals originating from bisexual and all-female populations. Populations with males are only found around the Mediterranean, whereas parthenogens cover most of Europe. The animals were hatched and grown in environments mimicking temperature and photoperiod conditions observed in Belgium and Spain. The data confirm the higher potential for population growth in parthenogens. In particular their faster hatching response, possibly higher fecundity (as derived from a difference in body height) and the absence of a cost of males should allow them to out-compete sexuals under stable conditions. However, the comparison of the hatchling accumulation curves of bisexual and all-female populations suggests that sexuals have an advantage in highly unpredictable environments. Indeed, under conditions mimicking those in southern Europe, bisexual populations exhibit a bet-hedging strategy, while parthenogenetic resting eggs hatch on average earlier and more synchronously. Overall, the life history data stress the importance of short term environmental fluctuations for the distribution of the sexes in E. virens , and probably many other inhabitants of ephemeral water bodies.     

Calcium protection of PS2 complex of Phaseolus coccineus from cadmium toxicity: In vitro study

The action of 10 and 20 mM Ca against harmful Cd effect on PS2 complex isolated from leaves of Phaseolus coccineus L. cv. Pi?kny Ja? was studied. The changes in fast chlorophyll a fluorescence induction kinetics and protein composition of PS2 complex were the symptoms of Cd toxicity and Ca protection of PS2 complex. Calcium applied at 10 mM concentration prevented F₀ reduction caused by the presence of 250–1000 μM Cd in the incubation mixture, but that of (the variable chlorophyll a fluorescence) F_v, F_m, F_v/F₀, and F_v/F_m only at 250 μM Cd. Ca concentration doubling in the incubation mixture resulted in complete overcoming the toxicity of 250–1000 μM Cd to F_v and F_m. However, the protection of F_v/F₀ and the photochemical efficiency of PS2 (F_v/F_m) from 1000 μM Cd was only partial even at 20 mM Ca. A protective effect of 10 mM Ca on D1, D2 and 17 kDa proteins was found in PS2 complex exposed to 250 μM Cd, and on 43 kDa protein in the complex treated with 500 μM Cd. However, 20 mM Ca counteracted the toxicity of 500 μM Cd to the 43, 47 and 17 kDa proteins, as well as the harmful effect of 1000 μM Cd on 47 and 17 kDa ones.