Neurotransmitter Specific,Cellular-Resolution Functional Brain Mapping Using Receptor Coated Nanoparticles: Assessment of the Possibility

Receptor coated resonant nanoparticles and quantum dots are proposed to provide a cellular-level resolution image of neural activities inside the brain. The functionalized nanoparticles and quantum dots in this approach will selectively bind to different neurotransmitters in the extra-synaptic regions of neurons. This allows us to detect neural activities in real time by monitoring the nanoparticles and quantum dots optically. Gold nanoparticles (GNPs) with two different geometries (sphere and rod) and quantum dots (QDs) with different sizes were studied along with three different neurotransmitters: dopamine, gamma-Aminobutyric acid (GABA), and glycine. The absorption/emission spectra of GNPs and QDs before and after binding of neurotransmitters and their corresponding receptors are reported. The results using QDs and nanorods with diameter 25nm and aspect rations larger than three were promising for the development of the proposed functional brain mapping approach.     

PEG activation and ligand binding for the affinity partitioning of proteins in aqueous two-phase systems

Summary PEG has been activated using epoxy-oxirane, epichlorohydrin and periodate based reactions. The coupling to activated PEG of several protein ligands of different sizes was investigated. Glutathione, trypsin inhibitor, Protein A and anti-BSA have been bound to PEG and used to increase the selectivity of protein separation in aqueous two-phase systems.     

Physiological and biochemical changes in Calanus hyperboreus from Jones Sound NWT during the transition from summer feeding to overwintering condition

Summary Several biochemical and physiological characteristics of stage V and female adult Calanus hyperboreus from two different depth ranges (0–50 m and 200–500 m) were compared at a time near the peak of the summer pelagic algal bloom in Jones Sound, and again one month later, when the near surface chlorophyll levels were low and most copepods had migrated to their overwintering dephts. For a given stage deep water animals were larger and had higher total lipid levels than did surface animals. Feeding activities, as evidenced by gut pigment contents, may be lower in animals at depth, although potential digestive activities, as expressed in the levels of three digestive enzymes, were not very different either in different stages or at different depths. Respiration rates in animals that had migrated down for the winter were not much lower than in those at the surface although energetic considerations suggest that they may decrease later. Ammonia excretion rates however, changed dramatically. Surface, feeding animals had the highest rates and deep water animals in September had undetectably (<1 ng atom ammonia nitrogen animal^-1 · day^-1) low rates.     

Giant lizards occupied herbivorous mammalian ecospace during the Paleogene greenhouse in Southeast Asia

Mammals dominate modern terrestrial herbivore ecosystems, whereas extant herbivorous reptiles are limited in diversity and body size. The evolution of reptile herbivory and its relationship to mammalian diversification is poorly understood with respect to climate and the roles of predation pressure and competition for food resources. Here, we describe a giant fossil acrodontan lizard recovered with a diverse mammal assemblage from the late middle Eocene Pondaung Formation of Myanmar, which provides a historical test of factors controlling body size in herbivorous squamates. We infer a predominately herbivorous feeding ecology for the new acrodontan based on dental anatomy, phylogenetic relationships and body size. Ranking body masses for Pondaung Formation vertebrates indicates that the lizard occupied a size niche among the larger herbivores and was larger than most carnivorous mammals. Paleotemperature estimates of Pondaung Formation environments based on the body size of the new lizard are approximately 2–5°C higher than modern. These results indicate that competitive exclusion and predation by mammals did not restrict body size evolution in these herbivorous squamates, and elevated temperatures relative to modern climates during the Paleogene greenhouse may have resulted in the evolution of gigantism through elevated poikilothermic metabolic rates and in response to increases in floral productivity.     

Distribution and Numbers of Pygmies in Central African Forests

Pygmy populations occupy a vast territory extending west-to-east along the central African belt from the Congo Basin to Lake Victoria. However, their numbers and actual distribution is not known precisely. Here, we undertake this task by using locational data and population sizes for an unprecedented number of known Pygmy camps and settlements (n = 654) in five of the nine countries where currently distributed. With these data we develop spatial distribution models based on the favourability function, which distinguish areas with favourable environmental conditions from those less suitable for Pygmy presence. Highly favourable areas were significantly explained by presence of tropical forests, and by lower human pressure variables. For documented Pygmy settlements, we use the relationship between observed population sizes and predicted favourability values to estimate the total Pygmy population throughout Central Africa. We estimate that around 920,000 Pygmies (over 60% in DRC) is possible within favourable forest areas in Central Africa. We argue that fragmentation of the existing Pygmy populations, alongside pressure from extractive industries and sometimes conflict with conservation areas, endanger their future. There is an urgent need to inform policies that can mitigate against future external threats to these indigenous peoples’ culture and lifestyles.     

Comparison of two techniques for quantifying environmental contaminants in human serum

Peak area matching and linear regression were used to quantify eight chlorinated pesticides and polychlorinated biphenyls (as Aroclor 1260) in human serum. There are no statistically significant differences in data obtained by these two quantifying techniques which were indicated by the paired t-test. For chlorinated pesticides, p = 0.053-0.62, and for polychlorinated biphenyls (as Aroclor 1260), p = 0.64. Analyte residues for the chlorinated pesticides ranged from 0.5 ppb for hexachlorobenzene (HCB) to 186 ppb for dichlorodiphenyldichloroethylene (DDE). Analyte residues for the polychlorinated biphenyls (as Aroclor 1260) ranged from 5-114 ppb. The absolute mean percent difference between the two quantifying techniques ranged from 0.06% for DDE to 8.06% for dieldrin (HEOD) among the chlorinated pesticides. The absolute mean percent difference between the two quantifying techniques for the polychlorinated biphenyls (as Aroclor 1260) was 3.4%. Peak area matching and linear regression were found to be comparable for quantifying these environmental residues in serum when the following conditions apply: 1) the concentration of the chlorinated pesticides is greater than or equal to 0.5 ppb (e.g., HCB, hexachlorocyclohexane (HCCH), oxychlordane (OC), heptachlor epoxide (HE), transnonachlor (TN), HEOD, and dichlorodiphenyltrichloroethane (DDT); 2) the concentration of the chlorinated pesticide is greater than or equal to 3 ppb (e.g., DDE); and 3) the total concentration of polychlorinated biphenyls (e.g., as Aroclor 1260) is greater than or equal to 5 ppb.     

Nonsymmetrical double logistic analysis of ambulatory blood pressure recordings.

We developed an asymmetric double logistic curve-fitting procedure for circadian analysis that can determine the rate of change in variables during the day-to-night separately from the night-to-day transition for use in animal studies. We now have applied this procedure to 24-h systolic (SAP) and diastolic arterial pressure (DAP) and heart rate ambulatory recordings from 302 patients. In 292 cases, all parameters showed a pattern of higher day and lower night values. In men there was a similar rate of transition between day and night or from night to day for both SAP and DAP that lasted 3-4 h, indicating a symmetrical diurnal pattern. By contrast, women showed a faster rate of decrease in mean arterial pressure in the evening compared with men (P < 0.05) and therefore showed an asymmetric diurnal SAP pattern. For both men and women, there was a markedly greater rate of morning increase in heart rate compared with the rate of evening decrease (2.2- and 1.9-fold, respectively, P < 0.001). The logistic method provided a better fit than the square-wave or the cosinor method (P < 0.001) and more appropriately detected nondippers. We conclude that analysis of ambulatory recordings by a new logistic curve-fitting method reveals more rapid reductions in evening SAP in women than men but both have two- to threefold more rapid morning rates of tachycardia. The ability of the double logistic method to determine the diurnal blood pressure rates of change independently is key to determining new markers for cardiovascular risk.     

QSAR modeling and transmission electron microscopy stereology of altered mitochondrial ultrastructure of white blood cells in patients diagnosed as schizophrenic and treated with antipsychotic drugs.

Treatment of patients diagnosed as schizophrenic with antipsychotic drugs (neuroleptics) is known to cause occasional unexplained depletion of white blood cells, especially neutrophil granulocytes. It has been known for many years that neuroleptics can interfere with the mitochondrial respiratory chain in vitro. Because there has been a growing interest recently in mitochondrial targeting of drugs, and since a quantitative structure-activity relationship (QSAR) model that predicts mitochondrial accumulation of neuroleptics has been published, we investigated the effects of neuroleptics on white blood cell mitochondria. Venous blood samples were collected from both patients undergoing treatment with neuroleptics and healthy volunteers. The samples were processed for transmission electron microscopy. The resulting images of white blood cells were analyzed using stereology to compare quantitatively mitochondrial morphology in the patient and control groups. We found that in patients, but not in controls, there was swelling of mitochondria and fragmentation of the mitochondrial cristae. There also were fewer mitochondria in patients than in controls, although due to the swelling of the organelles, the volume density of mitochondria in the two groups was not significantly different. Such changes are typical of a toxic insult. Consequently, it seems plausible that, since schizophrenia is not a disease considered to affect white blood cells per se, these changes probably are due to the medication.