Effects of protein deprivation and re-feeding on P2X(2) receptors in enteric neurons

AIM: To investigate the effects of malnutrition and refeeding on the P2X(2) receptor, nitric oxide synthase (NOS), calretinin, calbindin and choline acetyltransferase (ChAT) in neurons of the rat ileum. METHODS: We analyzed the co-localization, numbers and sizes of P2X(2)-expressing neurons in relation to NOS-IR (immunoreactive), calbindin-IR, ChAT-IR, and calretinin-IR neurons of the myenteric and submucosal plexus. The experimental groups consisted of: (1) rats maintained on normal feed throughout pregnancy until 42 d post-parturition (N); (2) rats deprived of protein throughout pregnancy and 42 d post-parturition (D); and (3) rats undernourished for 21 d post-parturition and then given a protein diet from days 22 to 42 (DR). The myenteric and submucosal plexuses were evaluated by double labeling by immunohistochemical methods for P2X(2) receptor, NOS, ChAT, calbindin and calretinin. RESULTS: We found similar P2X(2) receptor immunoreactivity in the cytoplasm and surface membranes of myenteric and submucosal neurons from the N, D and DR groups. Double labeling of the myenteric plexus demonstrated that approximately 100% of NOS-IR, calbindin-IR, calretinin-IR and ChAT-IR neurons in all groups also expressed the P2X(2) receptor. In the submucosal plexus, the calretinin-IR, ChAT-IR and calbindinIR neurons were nearly all immunoreactive for the P2X(2) receptor. In the myenteric plexus, there was a 19% increase in numbers per cm(2) for P2X(2) receptor-IR neurons, 64% for NOS-IR, 84% for calretinin-IR and 26% for ChAT-IR neurons in the D group. The spatial density of calbindin-IR neurons, however, did not differ among the three groups. The submucosal neuronal density increased for calbindin-IR, calretinin-IR and ChAT-IR neurons. The average size of neurons in the myenteric plexus neurons in the D group was less than that in the controls and, in the re-fed rats; there was a 34% reduction in size only for the calretinin-IR neurons. CONCLUSION: This work demonstrates that expression of the P2X(2) receptor is present in inhibitory, intrinsic primary afferent, cholinergic secretomotor and vasomotor neurons. Undernutrition affected P2X(2) receptor expression in the submucosal plexus, and neuronal and size. These changes were rescued in the re-fed rats. (C) 2010 Baishideng. All rights reserved.

Association of Trypanosoma vivax in extracellular sites with central nervous system lesions and changes in cerebrospinal fluid in experimentally infected goats

Changes in cerebrospinal fluid (CSF) and anatomical and histopathological central nervous system (CNS) lesions were evaluated, and the presence of Trypanosoma vivax in CNS tissues was investigated through PCR. Twelve adult male goats were divided into three groups (G): G1, infected with T. vivax and evaluated during the acute phase; G2, infected goats evaluated during the chronic phase; and G3, consisting of non-infected goats. Each goat from G1 and G2 was infected with 1.25 x 10(5) trypomastigotes. Cerebrospinal fluid (CSF) analysis and investigation of T. vivax was performed at the 15(th) day post-infection (dpi) in G1 goats and on the fifth day after the manifestation of nervous system infection signs in G2 goats. All goats were necropsied, and CNS fragments from G1 and G2 goats were evaluated by PCR for the determination of T. vivax. Hyperthermia, anemia and parasitemia were observed from the fifth dpi for G1 and G2, with the highest parasitemia peak between the seventh and 21(st) dpi. Nervous system infection signs were observed in three G2 goats between the 30(th) and 35(th) dpi. CSF analysis revealed the presence of T. vivax for G2. Meningitis and meningoencephalitis were diagnosed in G2. PCR were positive for T. vivax in all the samples tested. In conclusion, T. vivax may reach the nervous tissue resulting in immune response from the host, which is the cause of progressive clinical and pathological manifestations of the CNS in experimentally infected goats.

EPR study of local symmetry sites of Ce(3+) in Pb(1-x)Ce(x)A (A=S, Se, and Te)

The local site symmetry of Ce(3+) ions in the diluted magnetic semiconductors Pb(1-x)Ce(x)A (A=S, Se, and Te) has been investigated by electron-paramagnetic resonance (EPR). The experiments were carried out on single crystals with cerium concentration x ranging from 0.001 to 0.035. The isotropic line due to Ce(3+) ions located at the substitutional Pb cation site with octahedral symmetry was observed for all the studied samples. We determined the effective Lande factors to be g=1.333, 1.364, and 1.402 for A=S, Se, and Te, respectively. The small difference with the predicted Lande factor g of 10/7 for the Gamma(7) (J=5/2) ground state was attributed to crystal-field admixture. In addition, EPR lines from Ce(3+) ions located at sites with small distortion from the original octahedral symmetry were also observed. Two distinct sites with axial distortion along the < 001 > crystallographic direction were identified and a third signal in the spectrum was attributed to sites with the cubic symmetry distorted along the < 110 > direction. The distortion at these distinct Ce sites is attributed to Pb lattice vacancies near the cerium ions that compensate for its donor activity.

DFT and electrochemical studies on nortriptyline oxidation sites

A study on the possible sites of oxidation and epoxidation of nortriptyline was performed using electrochemical and quantum chemical methods; these sites are involved in the biological responses (for example, hepatotoxicity) of nortriptyline and other similar antidepressants. Quantum chemical studies and electrochemical experiments demonstrated that the oxidation and epoxidation sites are located on the apolar region of nortriptyline, which will useful for understanding the molecule`s activity. Also, for the determination of the compound in biological fluids or in pharmaceutical formulations, we propose a useful analytical methodology using a graphite-polyurethane composite electrode, which exhibited the best performance when compared with boron-doped diamond or glassy carbon surfaces.

Defining Nutrient and Biochemical Oxygen Demand Baselines for Tropical Rivers and Streams in So Paulo State (Brazil): A Comparison Between Reference and Impacted Sites

Determining reference concentrations in rivers and streams is an important tool for environmental management. Reference conditions for eutrophication-related water variables are unavailable for Brazilian freshwaters. We aimed to establish reference baselines for So Paulo State tropical rivers and streams for total phosphorus (TP) and nitrogen (TN), nitrogen-ammonia (NH(4) (+)) and Biochemical Oxygen Demand (BOD) through the best professional judgment and the trisection methods. Data from 319 sites monitored by the So Paulo State Environmental Company (2005 to 2009) and from the 22 Water Resources Management Units in So Paulo State were assessed (N = 27,131). We verified that data from different management units dominated by similar land cover could be analyzed together (Analysis of Variance, P = 0.504). Cumulative frequency diagrams showed that industrialized management units were characterized by the worst water quality (e.g. average TP of 0.51 mg/L), followed by agricultural watersheds. TN and NH(4) (+) were associated with urban percentages and population density (Spearman Rank Correlation Test, P < 0.05). Best professional judgment and trisection (median of lower third of all sites) methods for determining reference concentrations showed agreement: 0.03 & 0.04 mg/L (TP), 0.31 & 0.34 mg/L (TN), 0.06 & 0.10 mg-N/L (NH(4) (+)) and 2 & 2 mg/L (BOD), respectively. Our reference concentrations were similar to TP and TN reference values proposed for temperate water bodies. These baselines can help with water management in So Paulo State, as well as providing some of the first such information for tropical ecosystems.

Spectral characteristics of atrial electrograms in sinus rhythm correlates with sites of ganglionated plexuses in patients with paroxysmal atrial fibrillation

Aims To verify whether spectral components of atrial electrograms (AE) during sinus rhythm (SR) correlate with cardiac ganglionated plexus (GP) sites. Methods and results Thirteen patients undergoing atrial fibrillation (AF) ablation were prospectively enrolled. Prior to radio frequency application, endocardial AE were recorded with a sequential point-by-point approach. Electrical stimuli were delivered at 20 Hz, amplitude 100 V, and pulse width of 4 ms. A vagal response was defined as a high-frequency stimulation (HFS) evoked atrioventricular block or a prolongation of RR interval. Spectral analysis was performed on single AE during SR, sampling rate of 1000 Hz, Hanning window. Overall, 1488 SR electrograms were analysed from 186 different left atrium sites, 129 of them corresponding to negative vagal response sites, and 57 to positive response sites. The electrogram duration and the number of deflections were similar in positive and negative response sites. Spectral power density of sites with vagal response was lower between 26 and 83 Hz and higher between 107 and 200 Hz compared with negative response sites. The area between 120 and 170 Hz normalized to the total spectrum area was tested as a diagnostic parameter. Receiver operating characteristic curve analysis demonstrated that an area120-170/area(total) value >0.14 identified vagal sites with 70.9% sensitivity and 72.1% specificity. Conclusion Spectral analysis of AE during SR in sites that correspond to the anatomical location of the GP is feasible and may be a simpler method of mapping the cardiac autonomic nervous system, compared with the HFS technique.

Using a New Criterion to Identify Sites for Mean Soil Water Storage Evaluation

Establishing a few sites in which measurements of soil water storage (SWS) are time stable significantly reduces the efforts involved in determining average values of SWS. This study aimed to apply a new criterion the mean absolute bias error (MABE)-to identify temporally stable sites for mean SWS evaluation. The performance of MABE was compared with that of the commonly used criterion, the standard deviation of relative difference (SDRD). From October 2004 to October 2008, SWS of four soil layers (0-1.0, 1.0-2.0,2.0-3.0, and 3.0-4.0 m) was measured, using a neutron probe, at 28 sites on a hillslope of the Loess Plateau, China. A total of 37 SWS data sets taken over time were divided into two subsets, the first consisting of 22 dates collected during the calibration period from October 2004 to September 2006, and the second with 15 dates collected during the validation period from October 2006 to October 2008. The results showed that if a critical value of 5% for MABE was defined, more than half the sites were temporally stable for both periods, and the number of temporally stable sires generally increased with soil depth. Compared with SDRD, MABE was more suitable for the identification of time-stable sites for mean SS prediction. Since the absolute prediction error of drier sites is more sensitive to changes in relative difference in terms of mean SWS prediction, the sites of wet sectors should be preferable for mean SWS prediction for the same changes in relative difference.

Life history of Proctolaelaps bulbosus feeding on the coconut mite Aceria guerreronis and other possible food types occurring on coconut fruits

Aceria guerreronis Keifer (Acari: Eriophyidae) is a major pest of coconut fruits (Cocos nucifera L.) in many countries of the Americas, Africa, and parts of Asia. Considerable attention has been given to studies of biological control agents of A. guerreronis. Proctolaelaps bulbosus Moraes, Reis and Gondim Jr. is a predator recently discovered in association with A. guerreronis. Nothing is known about its biology. The aim of this study was to determine suitable food sources for P. bulbosus, among items commonly found on coconut fruits, including A. guerreronis. Food sources evaluated included the mites A. guerreronis, Steneotarsonemus concavuscutum Lofego and Gondim Jr., and Tyrophagus putrescentiae (Schrank), the fungus Rhizopus aff. stolonifer (Ehrenb.) Vuill and coconut pollen; the mite Tetranychus urticae Koch was also included in the assessments, for being a commonly used prey for mass production and laboratory rearing of predatory mites. Proctolaelaps bulbosus was able to develop up to adulthood when fed A. guerreronis, R. aff. stolonifer and T. putrescentiae. It had the highest population growth rates when feeding on the former (R (o) = 17.5; r (m) = 0.392). These results indicate that A. guerreronis is the most suitable food for P. bulbosus among the possible food sources found on coconut fruits and that P. bulbosus can survive in the absence of eriophyid using R. aff. stolonifer as a food source.

Vector within-host feeding preference mediates transmission of a heterogeneously distributed pathogen

2. We documented the within-host distribution of two vector species that differ in transmission efficiency, the leafhoppers Draeculacephala minerva and Graphocephala atropunctata, and which are free to move throughout entirely caged alfalfa plants. The more efficient vector D. minerva fed preferentially at the base of the plant near the soil surface, whereas the less efficient G. atropunctata preferred overwhelming the top of the plant. 3. Next we documented X. fastidiosa heterogeneity in mechanically inoculated plants. Infection rates were up to 50% higher and mean bacterial population densities were 100-fold higher near the plant base than at the top or in the taproot. 4. Finally, we estimated transmission efficiency of the two leafhoppers when they were confined at either the base or top of inoculated alfalfa plants. Both vectors were inefficient when confined at the top of infected plants and were 20-60% more efficient when confined at the plant base. 5. These results show that vector transmission efficiency is determined by the interaction between leafhopper within-plant feeding behaviour and pathogen within-plant distribution. Fine-scale vector and pathogen overlap is likely to be a requirement generally for efficient transmission of vector-borne pathogens.

Diet-dependent life history, feeding preference and thermal requirements of the predatory mite Neoseiulus baraki (Acari: Phytoseiidae)

Neoseiulus baraki Athias-Henriot (Acari: Phytoseiidae) has been reported from the Americas, Africa and Asia, often in association with Aceria guerreronis Keifer (Acari: Eriophyidae), one of the most important pests of coconut (Cocos nucifera L.) in diVerent parts of the world. That phytoseiid has been considered one of the most common predators associated with A. guerreronis in Brazil. The objective of this study was to evaluate the feeding preference and the eVect of food items commonly present on coconut fruits and several temperature regimes on the life history of a Brazilian population of N. baraki. Completion of immature development was possible when N. baraki was fed A. guerreronis, Steneotarsonemus concavuscutum Lofego and Gondim Jr., and Tyrophagus putrescentiae (Schrank). Fecundity was highest on T. putrescentiae (39.4 eggs), followed by A. guerreronis (24.8 eggs). In choice tests, irrespective of the food on which N. baraki was reared, a larger number of adults of this predator chose leaf discs containing A. guerreronis than discs containing other food items, demonstrating a preference of the former for the latter as food. Egg to adult thermal developmental time was calculated as 84.2 degree-days, above a threshold of 15.8 degrees C. This lower developmental threshold is higher than previously published for phytoseiid species from higher latitudes. Neoseiulus baraki was shown to have higher biotic potential at 30 degrees C (r(m) 0.29). The results suggest N. baraki to be a promising biological control agent of A. guerreronis, well adapted to survive and develop in areas with relatively high temperatures, where that pest prevails.

Feeding Dietary Mannan Oligosaccharides to Juvenile Nile Tilapis, Oreochromis niloticus, Has No Effect on Hematological Parameters and Showed Decreased Feed Consumption

Impaired immune system by environmental stressors can lead fishes to be more susceptible to diseases that limit the economic development of aquaculture systems. This study was set out to determine the effect of six levels of mannan oligosaccharides (MOS; ActiveMOS((R)); Biorigin, Lencois Paulista, Sao Paulo, Brazil) on the performance index and hematology of Nile tilapia, Oreochromis niloticus juveniles. Fish (13.62 g) were randomly distributed into 18 plastic aquaria (300 L; 20 fishes per aquarium) and fed during 45 d with a commercial diet supplemented with 0, 0.2, 0.4, 0.6, 0.8, and 1% dietary MOS, in a totally randomized design trial (n = 3); biometrical and hematological data were collected and analyzed. There were no significant differences in hematological parameters between fish fed control and MOS supplementation diets, and daily feed consumption (FC) decreased (P < 0.05) with increasing levels of dietary MOS. Dietary MOS did not increase leukocyte count and presented negative effects on FC of Nile tilapia. At 0.4% MOS supplementation, the individual weight gain was higher in absolute values but not different (P > 0.05) compared to control diet.

Winter-feeding systems for gestating sheep II. Effects on feedlot performance, glucose tolerance, and carcass composition of lamb progeny

Mature pregnant crossbred ewes (n = 90) were used in a randomized complete block design experiment and were assigned to 1 of 3 winter-feeding systems differing in primary feed source: haylage (HL), limit-fed corn (CN), or limit-fed dried distillers grains (DDGS). Effects of these winter-feeding strategies on postweaning progeny performance were determined. Lamb progeny (n = 96) were weaned at 61 +/- 4 d of age and fed a common high-concentrate diet. Lambs were assigned to feedlot pen (n = 18) based on dam mid-gestation pen. Growth rate, DMI, and ADG were determined for the first 40 d of the finishing period. At 96 +/- 4 d of age, 1 wether lamb was randomly selected from each pen (n = 18) for a glucose tolerance test. The experiment was terminated, and lambs were slaughtered individually when they were determined to have achieved 0.6-cm 12th-rib fat thickness. After a 24-h chill, carcass data were collected and a 2.54-cm chop was removed from each lamb from the LM posterior to the 12th rib for ether extract analysis. Additional carcass measurements of bone, muscle, and fat from the shoulder, rack, loin, and leg were collected on 35 carcasses. At weaning, lamb BW was not different among treatments, whereas final BW tended to be greater (P = 0.09) for lambs from ewes fed DDGS and CN during gestation than from those fed HL. Overall lamb growth rate from birth to slaughter was not different among treatments. Lambs from ewes fed DDGS vs. CN or HL tended to have a greater initial insulin response (P = 0.09). Dressing percent was less (P = 0.04) in lambs from ewes fed DDGS, but no difference (P = 0.16) was detected in HCW among treatments. As expected, 12th rib fat thickness was similar among treatments, whereas LM area was largest to smallest (P = 0.05) in lambs from ewes fed CN, HL, and DDGS, respectively. Proportion of internal fat tended to be greatest to smallest (P = 0.06) in lambs from ewes fed DDGS, CN, and HL, respectively. Calculated boneless trimmed retail cuts percentage was less (P = 0.04) in lambs from ewes fed DDGS than CN or HL. Loin muscle weight as a percentage of wholesale cut tended (P = 0.10) to be greater in lambs from ewes fed CN and HL than DDGS, whereas other muscle, bone, and fat weights and proportions were similar (P > 0.24) among treatments. Prepartum diet during mid to late gestation of ewes altered postnatal fat and muscle deposition and may be associated with alterations in insulin sensitivity of progeny.

Do Terrestrial Tank Bromeliads in Brazil Create Safe Sites for Palm Establishment or Act as Natural Traps for Its Dispersed Seeds ?

This study shows for the first time that terrestrial tank bromeliads from Brazilian restinga can act as natural traps for dispersed palm Euterpe edulis seeds. Such bromeliads, which are shade intolerant, gain benefits by limiting palm recruitment since they hinder canopy formation and, consequently, increase luminosity over its aggregates.

Sites of Defoliation by Atta sexdens rubropilosa (Hymenoptera, Formicidae) in Artificial Plants

This study aimed to achieve a better understanding about the foraging behavior of leaf-cutter ant (Atta sexdens rubropilosa Forel) workers with respect to defoliation sites in plants. To accomplish that, artificial plants 70 cm in height were prepared and divided into four levels (heights), having natural plant leaves attached to them. Evaluations during the bioassays included the number of leaves dropped by the ants, as well as the percentage of plant mass removed. In all replicates, it became evident that the most exploited plant site is the apical region, which significantly differed from other plant levels.

Cyclophosphamide levels in sites of preparation and administration of antineoplastic drugs

The extensive use of antineoplastic agents in chemotherapy may be at risk to health care workers involved in the preparation and administration of these drugs. In this study cyclophosphamide, a drug classified as a human carcinogen, was quantified by adapting a previous analytical method using gas chromatography coupled to mass spectrometry (GC-MS) after solid phase extraction with diatomaceous earth. The drug was measured by analysis in surfaces (wipe samples) and gloves, collected from four different hospitals, before and after the practice of cleaning procedures, and the use of a closed-system device for the preparation and administration. Validation results were satisfactory and cyclophosphamide levels ranging from below the quantification limit to 141000 ng. Our findings demonstrated that surfaces and materials contamination was found in all hospitals during the traditional open technique for preparation and administration of cyclophosphamide and a significant reduction in contamination when a closed-system device was used. However, some values were considered unexpected, especially those obtained from samples collected after the cleaning surfaces.