Editing of CD1d-bound lipid antigens by endosomal lipid transfer proteins

It is now established that CD1 molecules present lipid antigens to T cells, although it is not clear how the exchange of lipids between membrane compartments and the CD1 binding groove is assisted. We report that mice deficient in prosaposin, the precursor to a family of endosomal lipid transfer proteins (LTP), exhibit specific defects in CD1d-mediated antigen presentation and lack Valpha14 NKT cells. In vitro, saposins extracted monomeric lipids from membranes and from CD1, thereby promoting the loading as well as the editing of lipids on CD1. Transient complexes between CD1, lipid, and LTP suggested a "tug-of-war" model in which lipid exchange between CD1 and LTP is on the basis of their respective affinities for lipids. LTPs constitute a previously unknown link between lipid metabolism and immunity and are likely to exert a profound influence on the repertoire of self, tumor, and microbial lipid antigens.     

Late-Neoproterozoic deep-ocean oxygenation and the rise of animal life

Because animals require oxygen, an increase in late-Neoproterozoic oxygen concentrations has been suggested as a stimulus for their evolution. The iron content of deep-sea sediments shows that the deep ocean was anoxic and ferruginous before and during the Gaskiers glaciation 580 million years ago and that it became oxic afterward. The first known members of the Ediacara biota arose shortly after the Gaskiers glaciation, suggesting a causal link between their evolution and this oxygenation event. A prolonged stable oxic environment may have permitted the emergence of bilateral motile animals some 25 million years later.     

High molecular weight glutenin subunits in some durum wheat cultivars investigated by means of mass spectrometric techniques

The primary structures of high molecular weight glutenin subunits (HMW-GS) of 5 Triticum durum Desf. cultivars (Simeto, Svevo, Duilio, Bronte, and Sant'Agata), largely cultivated in the south of Italy, and of 13 populations of the old spring Sicilian durum wheat landrace Timilia (Triticum durum Desf.) (accession nos. 1, 2, 3, 4, 7, 8, 9, 13, 14, 15, SG1, SG2, and SG3) were investigated using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) and reversed-phase high performance liquid chromatography/nanoelectrospray ionization mass spectrometry (RP-HPLC/nESI-MS/MS). M(r) of the intact proteins determined by MALDI mass spectrometry showed that all the 13 populations of Timilia contained the same two HMW-GS with 75.2 kDa and 86.4 kDa, whereas the other durum wheat cultivars showed the presence of the expected HMW-GS 1By8 and 1Bx7 at 75.1 kDa and 83.1 kDa, respectively. By MALDI mass spectrometry of the tryptic digestion peptides of the isolated HMW-GS of Timilia, the 1Bx and 1By subunits were identified as the NCBInr Acc. No AAQ93629, and AAQ93633, respectively. Sequence verification for HMW-GS 1Bx and 1By both in Simeto and Timilia was obtained by MALDI mass mapping and HPLC/nESI-MSMS of the tryptic peptides. The Bx subunit of Timila presents a sequence similarity of 96% with respect to Simeto, with differences in the insertion of 3 peptides of 5, 9, and 15 amino acids, for a total insertion of 29 amino acids and 25 amino acid substitutions. These differences in the amino acidic sequence account for the determined Δm of 3294 Da between the M(r) of the 1Bx subunits in Timilia and Simeto. Sequence alignment between the two By subunits shows 10 amino acid substitutions and is consistent with the Δm of 148 Da found in the MALDI mass spectra of the intact subunits.     

Foliar and soil deposition of pesticide sprays in peanuts and their washoff and runoff under simulated worst-case rainfall conditions

There are few studies that relate the timing and amounts of pesticide washoff from plant foliage during rainfall to runoff losses at the edge of the field. We hypothesized that foliar deposits, if washed onto the soil slowly during rainfall, may then undergo less leaching during the period of infiltration that occurs prior to soil saturation and runoff, thus exhibiting larger runoff losses than pesticides on/in the soil at the beginning of rain. We measured the runoff of ethalfluralin, metolachlor, chlorothalonil, and rhodamine WT dye using simulated rainfall on 450 m2 mesoplots planted in peanut. Ethalfluralin was applied preplant incorporated, and metolachlor was applied preemergence on bare soil. Chlorothalonil and rhodamine WT were applied to the peanut canopy at maturity. Rainfall was simulated 24 h after each chemical application (in May and July, 1998, and May and August, 1999) using raindrop sprinklers, applying 5.5 +/- 0.5 cm over a 2 h period to create reasonable worst-case conditions; between 3 and 9 mm of runoff was generated. Volume-weighted average concentrations of chemicals in runoff were 7, 104, 163, and 179 ug L(-1) for ethalfluralin, metolachlor, chlorothalonil, and rhodamine WT, respectively. The total amounts of chemicals lost in the runoff events were 0.04 +/- 0.01, 0.2 +/- 0.1, 0.6 +/- 0.5, and 0.2 +/- 0.1, as percents of amounts applied, respectively. Rhodamine WT formed a vivid red solution on wetting and provided visual clues to the dynamics of chemical washoff/runoff. The washoff from rain-exposed peanut foliage appeared to be complete within a few minutes of the beginning of rainfall, and disappearance of dye from rain-exposed soil surface occurred within the first 10 min of rainfall. However, dye was present in runoff water at near-constant concentrations throughout the 2 h runoff event, indicating that near-constant amounts of chemical remained in the soil extraction zone. These results confirm earlier studies showing that soil incorporation at application significantly reduces runoff losses and that a majority of foliar residues can be washable if rainfall occurs within a few days after application. Runoff losses of foliar-applied pesticides were small relative to washoff amounts but were sensitive to runoff timing relative to washoff.     

Economic Feasibility of Small-Scale Sponge Farming in Pohnpei,Federated States of Micronesia1

Interest exists in the commercial culture of sponges in the Pohnpei region of the Federated States of Micronesia. Sponge culture is appealing in that capital and labor investment is minimal. Investment requirements for a 0.4-ha sponge farm totals $650. Average annual production costs total $500. The sponge farm yields 2,400 sponges per 0.4 ha annually. Annual net returns are approximately $1,744 per 0.134 ha component, beginning in Year 4. Profitability is most sensitive to changes in opportunity wage rate, survival rate, and market price. Commercial sponge farming in Pohnpei shows promise as a source of supplemental income.     

Internal parasites in calves and heifers in a central rearing barn

In the specialised rearing house for young cattle of all age groups the occurrence of endoparasites was followed. In the age group of 21 to 90 days, 56% of calves aged about 30 days eliminated oocysts of coccidia. On the whole, 49.3% of calves were infested by coccidia, 3% by enterohelminths. 90.3% of calves aged from three to six months were parasitised by coccidia, 7.4% by enterohelminths. Young cattle, aged from 6 to 12 months, were parasitised in 94.6% by coccidia and in 14.1% by enterohelminths. 86.6% of pregnant heifers at the age of 14 to 19 months had coccidia, 7.7% enterohelminths. The total farm capacity was about 950 animals. Throughout the year the number of examined animals amounted to 1,195, out of this number 958 animals, i. e. 80.2%, were infested by coccidia, 55.6% of animals by the species Eimeria bovis, 47.0% by E. zuernii, 43.3% by E. auburnensis, 39.4% by E. ellipsoidalis, 25.2% by E. cylindrica, 13.6% by E. subspherica, 3.1% by E. bukidnonensis, 1.7% by Isospora spp., 0.4% by E. brasiliensis, 0.08% by E. pellita. Enterohelminths were observed only in 96 animals, i. e. in 8.03%. Trichocephalus was found in 3.9% of animals, Cooperia in 2.4%, Ostertagia in 0.6%, Chabertia in 0.4%, Nematodirus in 0.3%, Capillaria in 0.2%, Oesophagostomum in 0.2%, Bunostomum in 0.1% and Trichostrongylus in 0.1%. The highest elimination of oocysts of coccidia was observed in August, January and February, of eggs of enterohelminths from August to October. In all age groups the most frequent was the occurrence of pathogenic species of coccidia.     

Imaging: Nuclear*

In this paper an overview of principles involved in nuclear imaging is presented. Nuclear images are picotrial representations of the distribution of systemically administered radiopharmaceuticals. Although many radionuclides are available. ^99mTc is the most commonly used radionuclide, either in ionic form (^99mTcO₄) or bound to other pharmaceuticals. Distribution within the body is by physiologic processes, dependent on the radiopharmaceutical used. Most distribution processes are organ specific rather than disease specific. Scintillation detectors are used to record the activity and disribution of an administered radiopharmaceutical and to create a representative image on film. A rectilinear scanner is an imaging system with a small detector that moves systematically, point by point, over an organ of interest. A gamma (scintillation) camera is an imaging system with a large stationary detector that encompasses a larger field of view. Nuclear imaging provides information based primarily on physiologic principles, and radiography provides infromation based primarily on anatomic or geometric principles. Examples of some scanning procedures are discussed.     

Adherence as a Prerequisite for Infection of the Bovine Mammary Gland by Bacteria

Using a simple in vitro test it was demonstrated that staphylococci, Streptococcus agalactiae, and micrococci, the species of bacteria which are commonly isolated from udder infections, adhered to mammary gland epithelial cells readily and in large numbers. Some strains of organisms which are associated with sporadic outbreaks or occur less commonly, like Str. dysgalactiae and Str. uberis, adhered moderately. Escherichia coli, Klebsiella spp., Corynebacterium pyogenes, C. bovis, Str. bovis, and Str. faecalis, species which are isolated occasionally, adhered poorly. From these studies, it appears that selective adherence of bacteria to the epithelial cells is a factor contributing to the ability of organisms to infect the mammary gland and may, therefore, be considered an important stage in the pathogenesis of bovine mastitis.