Serotonin 5-HT2 receptor binding on blood platelets - a peripheral marker for depression?

Several methods of platelet membrane preparation and binding conditions were screened in order to optimize the labeling of serotonergic 5-HT2 receptors on previously frozen human platelet membranes with tritiated ketanserin. Under optimal conditions, 5-HT2 receptors in normal subjects (5 males, 7 females, age range 21 to 71) have a Kd of 1.5 +/- 0.2 nM and a Bmax of 33.9 +/- 5.3 fmole/mg protein. In a group of patients with major depressive disorder exactly matched for age and sex with the normal control group, we find a significant increase in receptor density, to 66.8 +/- 11.4 fmole/mg, with no significant change in the affinity (2.3 +/- 0.5 nM). Four weeks of treatment with antidepressant drugs result in a significant decrease of Bmax, down to control levels (29.4 +/- 3.9). Thus, ketanserin can be used to monitor changes in platelet serotonin 5-HT2 receptors which may be a relevant marker for the state of depression.     

Metabolism of monoterpenes: demonstration of the hydroxylation of (+)-sabinene to (+)-cis-sabinol by an enzyme preparation from sage (Salvia officinalis) leaves

A microsomal preparation from the epidermis of Salvia officinalis leaves catalyzed the NADPH- and O2-dependent hydroxylation of the monoterpene olefin (+)-sabinene to (+)-cis-sabinol. The reaction catalyzed is a key step in the biosynthesis of C3-oxygenated thujane monoterpenes, and the hydroxylase is highly specific for (+)-sabinene as substrate. The hydroxylase from leaf homogenates was solubilized and characterized with regard to reaction conditions, inhibitors, and activators. Activity was partially inhibited by rabbit anti-rat cytochrome P-450 and by CO, and the latter inhibition was reversed by 450 nm light. A CO-difference spectrum and type I substrate binding spectrum were obtained. The hydroxylase meets most of the established criteria for a cytochrome P-450-dependent mixed function oxygenase and represents one of very few enzyme systems of this type to be isolated from leaves of a higher plant.     

Effect of Cd-containing wood ash on the microflora of coniferous forest humus

The use of wood ash in forestry has been questioned because the cadmium (Cd) concentration of ash, which varies between 1 and 20 mg kg(-1) ash, exceeds the level allowed for fertilizers (3 mg kg(-1)) used in agriculture. To investigate the combined and separated effects of Cd and ash on the forest humus microflora, pumice or wood ash, spiked with a water-soluble (CdCl(2)) or -insoluble (CdO) form of Cd at three levels (0, 400 and 1000 mg kg(-1)), were applied at a fertilization level of 5000 kg ha(-1) in a laboratory microcosm study. The trial consisted of 60 microcosms (five replications per treatment), which were incubated in darkness at +20 degrees C and a constant relative air humidity of 60%. After two months the humus in the microcosms was sampled. Analyses of CO(2) evolution to measure the overall microbial activity and of phospholipid fatty acid (PLFA) pattern to measure microbial community structure were performed. The substrate-use patterns of Biolog EcoPlates were analyzed as a measure of bacterial functionality. Finally the bacterial (3)H-thymidine incorporation in the presence of different concentrations of Cd and the number of colony forming units (cfu) of bacteria on nutrient agar in the presence of 0, 5 and 20 mg Cd l(-1) agar were applied to measure Cd tolerance. The use of pumice (pH of humus under the pumice 4.0) did not induce any changes in the above variables compared to two untreated microcosms (humus pH 3.9). Pumice was therefore used to distribute the Cd evenly over the humus surface in order to estimate the possible effect of Cd without ash (pH of humus under the ash 7.0). The application of ash increased the microbial activity, changed the PLFA and substrate-use patterns and increased cfu compared to the humus under pumice. The form and level of Cd in the ash had no further effect on this result. In the humus under pumice the level, but not the form of Cd decreased the microbial activity and changed the PLFA pattern compared to the unspiked pumice. None of the treatments induced bacterial tolerance to Cd. Ash thus protected the humus microflora from the harmful effects of Cd.     

Maximizing gain from rectangular tissue expanders.

Three different options are proposed to cut the flap after expansion of rectangular tissue expanders. Each method, when used effectively, allows the expander to deliver the full punch of the expansion process.     

3H-amino acid uptake and incorporation in sea urchin gastrulae and exogastrulae: an autoradiographic study.

Autoradiographic analysis of gastrulae of the sea urchin, Lytechinus pictus, after brief incubation periods with 3H-amino acids has indicated that the cells of the ectoderm incorporate significantly greater levels of isotope than the cells of the interior. Further analysis based primarily on incorporation patterns of exogastrulae indicate that the greatly lowered incorporation by the cells of the archenteron reflects the inability of small molecular weight precursors to reach the invaginated cells. The maintenance of high levels of 3H-amino acid incorporation by ectodermal cells of exogastrulae indicates their relative independence with respect to macromolecular metabolism from the cells of the archenteron.     

Isolation and characterization of polymorphic microsatellites in Cocos nucifera L.

Microsatellites or simple sequence repeats (SSRs) were isolated from coconut (Cocos nucifera) and tested for polymorphism on restricted germplasm. Sequencing of 197 clones from a cv. Tagnanan Tall-enriched genomic library showed that 75% contained a microsatellite, of which 64% were dinucleotide (GA/CT, CA/GT and GC/CG), 6% were trinucleotide, and 30% were compound repeats. Of 41 primer pairs tested on Tagnanan Tall genomic DNA, 38 gave the expected size product, two amplified two loci, and another gave a multilocus pattern. On 20 coconut samples, the 38 SSRs detected 198 alleles (average: 5.2 alleles per microsatellite). Genetic diversity (D = 1 - sigma pi2) values ranged from 0.141 to 0.809. Heterozygotes were present at high frequencies among some dwarf samples. Analysis of similarity matrices based either on shared alleles at each locus (simple matching coefficient) or on allele bands across all loci (Jaccard coefficient) showed similar results. Dwarfs grouped separately from talls and showed less genetic diversity. In a wider test on 40 samples, 8 SSRs detected 64 alleles (average: eight alleles per microsatellite). These results indicate the high potential of microsatellites to detect genetic diversity in coconut germplasm.     

Analysis off cereal chromosomes by atomic force microscopy.

Atomic force microscopy has been applied to the study of plant chromosomes from cereal grasses Triticum aestivum (bread wheat), Triticum tauschii, and Hordeum vulgare (barley). Using standard mitotic metaphase squashes, high resolution images have been obtained of untreated chromosomes and also of chromosomes after C-banding, N-banding, and in situ hybridization. The true 3-dimensional nature of the images permits detailed analysis of the surface structure and, on untreated uncoated chromosomes, surface features on a length scale consistent with nucleosome structures have been observed. C+ and N+ regions are manifest as areas of high relief on a slightly collapsed chromosome structure. In situ hybridization leads to a more severe degradation of the native structure, although it is still possible to correlate the optical signal with the topography of the hybridized chromosome. Key words : atomic force microscope, AFM, chromosomes, C-banding, in situ hybridization.     

An algorithm combining discrete and continuous methods for optical mapping.

Optical mapping is a novel technique for generating the restriction map of a DNA molecule by observing many single, partially digested copies of it, using fluorescence microscopy. The real-life problem is complicated by numerous factors: false positive and false negative cut observations, inaccurate location measurements, unknown orientations, and faulty molecules. We present an algorithm for solving the real-life problem. The algorithm combines continuous optimization and combinatorial algorithms applied to a nonuniform discretization of the data. We present encouraging results on real experimental data and on simulated data.     

Can immunological principles and cross-disciplinary science illuminate the path to vaccines for HIV and other global health challenges?

Vaccines are one of the most impactful and cost-effective public health measures of the twentieth century. However, there remain great unmet needs to develop vaccines for globally burdensome infectious diseases and to allow more timely responses to emerging infectious disease threats. Recent advances in the understanding of immunological principles operative not just in model systems but in humans in concert with the development and application of powerful new tools for profiling human immune responses, in our understanding of pathogen variation and evolution, and in the elucidation of the structural aspects of antibody–pathogen interactions, have illuminated pathways by which these unmet needs might be addressed. Using these advances as foundation, we herein present a conceptual framework by which the discovery, development and iterative improvement of effective vaccines for HIV, malaria and other globally important infectious diseases might be accelerated.