Electrical immunosensor based on a submicron-gap interdigitated electrode and gold enhancement

We demonstrated that the detection of human interleukin 5 (IL5) with a higher sensitivity than the enzyme-linked immunosorbent assay (ELISA) was possible using mass-producible submicron-gap interdigitated electrodes (IDEs) combined with signal amplification by a gold nanoparticle (AuNP) and gold enhancement. IDEs, facing comb-shape electrodes, can act as simple and miniaturized devices for immunoassay. An IDE with a gap size of 400nm was fabricated by a stepper photolithography process and was applied for the immunoassay of human IL5. A biotinylated anti-human IL5 was immobilized on the streptavidin-modified IDE, and biotin-bovine serum albumin (BSA) and BSA were added sequentially to reduce non-specific binding between the streptavidin-immobilized IDE surface and other proteins. The immunoassay procedure included three main steps: the reaction of human IL5 to form antigen-antibody complexes, the binding of AuNP conjugation with an antibody against human IL5 for the sandwich immunoassay, and gold enhancement for electrical signal amplification. The measurement of electrical current at each step showed that the gold enhancement step was very critical in detection of the concentration of human IL5. Analysis by scanning electron microscope (SEM) showed that close to 1μm particles were formed from 10nm AuNP by the gold enhancement reaction using gold ions and hydroxylamine. Under optimized conditions, human IL5 could be analyzed at 1pgmL(-1) with a wide dynamic range (from 10(-3) to 100ngmL(-1) concentrations).     

Chromium in Postmortem Material

Recently, considerable attention has been paid to the negative effects caused by the presence and constant increase in concentration of heavy metals in the environment, as well as to the determination of their content in human biological samples. In this paper, the concentration of chromium in samples of blood and internal organs collected at autopsy from 21 female and 39 male non-occupationally exposed subjects is presented. Elemental analysis was carried out by an electrothermal atomic absorption spectrometer after microwave-assisted acid digestion. Reference ranges of chromium in the blood, brain, stomach, liver, kidneys, lungs, and heart (wet weight) in the population of Southern Poland were found to be 0.11–16.4 ng/mL, 4.7–136 ng/g, 6.1–76.4 ng/g, 11–506 ng/g, 2.9–298 ng/g, 13–798 ng/g, and 3.6–320 ng/g, respectively.     

Construction of dextrin and isomaltose-assimilating brewer’s yeasts for production of low-carbohydrate beer

Most Saccharomyces spp. cannot degrade or ferment dextrin, which is the second most abundant carbohydrate in wort for commercial beer production. Dextrin-degrading brewer’s bottom and top yeasts expressing the glucoamylase gene (GAM1) from Debaryomyces occidentalis were developed to produce low-carbohydrate (calorie) beers. GAM1 was constitutively expressed in brewer’s yeasts using a rDNA-integration system that contained yeast CUP1 gene coding for copper resistance as a selective marker. The recombinants secreted active glucoamylase, displaying both α-1,4- and α-1,6-debranching activities, that degraded dextrin and isomaltose and consequently grew using them as sole carbon source. One of the recombinant strains expressing GAM1 hydrolyzed 96 % of 2 % (w/v) dextrin and 98 % of 2 % (w/v) isomaltose within 5 days of growth. Growth, substrate assimilation, and enzyme activity of these strains were characterized.     

Post-castration retention of reproductive behavior and olfactory preferences in male Siberian hamsters: role of prior experience

Reproductive behavior of virtually all adult male rodents is dependent on concurrent availability of gonadal steroids. The ejaculatory reflex is incompatible with long-term absence of testicular steroids and typically disappears within 3 weeks after castration. Male Siberian hamsters are an exception to this rule; mating culminating in the ejaculatory reflex occurs as many as 6 months after castration (persistent copulation). The emergence of persistent copulation many weeks after gonadectomy is here shown not to require repeated post-castration sexual experience. Preoperative sexual experience, on the other hand, significantly increases the percent of males that copulate after gonadectomy, but is not required for the emergence of this trait in 25% of males. Castration prior to puberty prevents persistent copulation in all individuals in adulthood. Persistent copulators, unlike males that cease mating activity after castration, prefer the odors of estrous over non-estrous females when tested 4 months after castration and 7 weeks after the last mating test. Neural circuits of persistent copulators retain the ability to mediate male sex behavior and preferences for female odors in the complete absence of gonadal steroids; they are influenced by preoperative sexual experience and organizational effects of gonadal hormones at the time of puberty.     

Schistosoma mansoni-Related Hepatosplenic Morbidity in Adult Population on Kome Island,Sengerema District,Tanzania

Schistosomiasis is one of the important neglected tropical diseases (NTDs) in Tanzania, particularly in Lake Victoria zone. This baseline survey was a part of the main study of integrated control of schistosomiasis and soil-transmitted helminths (STHs) aimed at describing morbidity patterns due to intestinal schistosomiasis among adults living on Kome Island, Sengerema District, Tanzania. Total 388 adults from Kome Islands (about 50 people from each village) aged between 12 and 85 years, were examined by abdominal ultrasound according to the Niamey protocol. Liver image patterns (LIPs) A and B were considered normal, and C-F as distinct periportal fibrosis (PPF). The overall prevalence of PPF was 42.2%; much higher in males than in females (47.0% in male vs 34.4% in females, P=0.007). Abnormal increase of segmental branch wall thickness (SBWT) and dilated portal vein diameter (PVD) were also more common in males than in females. Hepatosplenomegaly was frequently encountered; 68.1% had left liver lobe hepatomegaly and 55.2% had splenomegaly. Schistosoma mansoni-related morbidity is quite high among adults in this community justifying the implementation of integrated control strategies through mass drug administration, improved water supply (pumped wells), and health education that had already started in the study area.     

Purification and Properties of a New l-Fucose-specific Lectin Produced by Streptomyces No. 100–2

The inhibitory effects of 3-nitro-2,4,6-trihydroxybenzamide derivatives on human 5-lipoxygenase (5-LO), a key enzyme in arachidonic acid cascades, were examined using 5-LO produced by Escherichia coli. Some of the tested compounds inhibited the conversion of arachidonic acid to 5-hydroperoxy-6,8,11,14-eicosatetraenoic acid (5-HPETE), and in particular the N-phenylbutyl derivative was about 30 times more active (IC₅₀ = 35 μm) than caffeic acid (IC₅₀ = 1000 μm), a known selective 5-LO inhibitor.     

Isolation and characterization of 15 microsatellite loci in four endangered Amentotaxus species (Taxaceae)

? Premise of the study: Fifteen microsatellite loci were developed in an endangered species, Amentotaxus formosana, and were tested in an additional three species, A. argotaenia, A. yunnanensis, and A. poilanei, to evaluate the population structure for conservation efforts and reconstruct the phylogeographic patterns of this ancient lineage. ? Methods and Results: Polymorphic primer sets were developed from A. formosana; the number of alleles ranged from two to 10, with an observed heterozygosity ranging from 0 to 0.60. All of the loci were found to be interspecifically amplifiable. ? Conclusions: These polymorphic and transferable loci will be potentially useful for future studies that will focus on identifying distinct genetic units within species and establishing the phylogeographic patterns and the process of speciation among closely related species.     

Pax3 function is required specifically for inner ear structures with melanogenic fates

Pax3 mutations result in malformed inner ears in Splotch mutant mice and hearing loss in humans with Waardenburg’s syndrome type I. In the inner ear, Pax3 is thought to be involved mainly in the development of neural crest. However, recent studies have shown that Pax3-expressing cells contribute extensively to multiple inner ear structures, some of which were considered to be derived from the otic epithelium. To examine the specific functions of Pax3 during inner ear development, fate mapping of Pax3 lineage was performed in the presence or absence of functional Pax3 proteins using Pax3^Cre knock-in mice bred to Rosa26 reporter (R26R) line. β-gal-positive cells were widely distributed in Pax3^Cre/+; R26R inner ears at embryonic day (E) 15.5, including the endolymphatic duct, common crus, cristae, maculae, cochleovestibular ganglion, and stria vascularis. In the absence of Pax3 in Pax3^Cre/Cre; R26R inner ears, β-gal-positive cells disappeared from regions with melanocytes such as the stria vascularis of the cochlea and dark cells in the vestibule. Consistently, the expression of Dct, a melanoblast marker, was also absent in the mutant inner ears. However, when examined at E11.5, β-gal positive cells were present in Pax3^Cre/Cre mutant otocysts, whereas Dct expression was absent, suggesting that Pax3 lineage with a melanogenic fate migrated to the inner ear, yet failed to differentiate and survive without Pax3 function. Gross inner ear morphology was generally normal in Pax3^Cre/Cre mutants, unless neural tube defects extended to the cranial region. Taken together, these results suggest that despite the extensive contribution of Pax3-expressing cells to multiple inner ear tissues, Pax3 function is required specifically for inner ear components with melanogenic fates.