Taxonomy ofCarminatia (Asteraceae,Eupatorieae)

A taxonomic study of the largely Mexican genusCarminatia is rendered. It is comprised of three closely related species:C. tenuiflora, C. recondita andC. anomala spec. nova. Illustrations, dot maps, keys to species and complete synonymy are presented.     

Purified moniliformin does not affect the force or rate of contraction of isolated guinea pig atria

Aspergillus flavus Link ex Fries and A. parasiticus Speare can invade peanut kernels and under certain environmental conditions produce unacceptable levels of the mycotoxin aflatoxin. A concerted effort is underway to reduce aflatoxin contamination in peanut and peanut products. A potentially effective method of control in peanut is the discovery and use of genes for resistance to either fungal invasion or aflatoxin formation. The objective of the present experimental study was to develop an effective and efficient procedure for screening individual plants or pods of single plants for resistance to invasion by the aflatoxigenic fungi and subsequent aflatoxin production. Methods of obtaining adequate drought-stress and fungal infection were developed through this series of experiments. By completely isolating the pods from the root zone and imposing drought-stress only on pegs and pods, high levels of fungal infection were observed. High amounts of preharvest aflatoxin accumulation were also produced by completely isolating the pods from the root zone. Mid-bloom inoculation with A. parasiticus-contaminated cracked corn and drought-stress periods of 40 to 60 days were the most effective procedures. This technique was used to assess peanut genotypes previously identified as being partially resistant to A. parasiticus infection or aflatoxin contamination, and segregating populations from four crosses. Variability in aflatoxin contamination was found among the 11 genotypes evaluated, however, none were significantly lower than the standard cultivars. Broad-sense heritability of four crosses was estimated through evaluation of seed from individual plants in the F₂ generation. The heritability estimates of crosses GFA-2 × NC-V11 and Tifton-8 × NC-V11 were 0.46 and 0.29, respectively, but mean aflatoxin contamination levels were high (73,295 and 27,305 ppb). This greenhouse screening method could be an effective tool when genes for superior aflatoxin resistance are identified.Cooperative investigation of the USDA-ARS and the University of Georgia, College of Agriculture.     

EVOLUTIONARY IMPLICATIONS OF INTRASPECIFIC CHLOROPLAST DNA VARIATION IN DWARF DANDELIONS (KRIGIA; ASTERACEAE)

Intraspecific chloroplast DNA polymorphisms were examined for 51 populations of seven species in the genus Krigia. A total of 1,100 restriction sites was surveyed and 46 of these were variable at the intraspecific level. Twenty-two of the variable sites were found within K. virginica, giving this species one of the highest levels of intraspecific chloroplast DNA divergence of any examined species. In contrast, no restriction site variation was detected within K. dandelion, K. wrightii, and K. occidentalis. Five polymorphisms were identified from the 16 populations of the K. cespitosa-gracilis complex, but no mutations distinguished the K. cespitosa and K. gracilis types. Krigia montana and K. biflora showed 11 and eight restriction site polymorphisms, respectively. The chloroplast genome of the hexaploid K. montana was derived from the diploid K. biflora rather than the tetraploid K. montana. High levels of polymorphism were found in species having different ploidy levels, such as K. virginica, K. biflora, and K. montana. Furthermore, most mutations found in these three species were recorded from the tetraploid lineages. As a result, evolutionary rates between different ploidy levels differ significantly. The chloroplast DNA restriction site data suggest that all surveyed populations of the autotetraploid K. virginica originated from a common ancestor. Our results also indicate that certain regions of the chloroplast genome have changed more rapidly than others and have the potential to resolve evolutionary questions at the population level.     

Rhesus monkey micro mixed lymphocyte and mitogen reactivity: Optimal conditions and normal variability

Optimal conditions for the rhesus monkey micro mixed lymphocyte system with multiple automated harvesting of samples were evaluated. Parameters studied were cell concentration, length of culture period, methods of inactivation of cell populations, supplementation of media, type of culture plates, and changes in the reactivity of cells from individual animals over an extended time period. This work was supported in part by Portland Veterans Administration Hospital, Portland, Oregon, and the General Research Support Branch of the U.S. Public Health Service Grant RR00163, the Bureau of Medicine and Surgery, Navy Department, Work Unit No. M4318. 01.007ABG2. The opinions or assertions contained herein are the private ones of the authors and are not to be construed as official or reflecting the views of the U.S. Navy Department or the Naval service at large. The animals used in this study were handled in accordance with the provisions of Public Law 89–54 as amended by Public Law 91–579, “Animal Welfare Act of 1970,” and the principles outlined in the “Guide for the Care of Laboratory Animals,” U.S. Department of Health, Education, and Welfare Publication No. (NIH) 73-23.     

Transposable Element ISHp608 of Helicobacter pylori: Nonrandom Geographic Distribution, Functional Organization, and Insertion Specificity

A new member of the IS605 transposable element family, designated ISHp608, was found by subtractive hybridization in Helicobacter pylori. Like the three other insertion sequences (ISs) known in this gastric pathogen, it contains two open reading frames (orfA and orfB), each related to putative transposase genes of simpler (one-gene) elements in other prokaryotes; orfB is also related to the Salmonella virulence gene gipA. PCR and hybridization tests showed that ISHp608 is nonrandomly distributed geographically: it was found in 21% of 194 European and African strains, 14% of 175 Bengali strains, 43% of 131 strains from native Peruvians and Alaska natives, but just 1% of 223 East Asian strains. ISHp608 also seemed more abundant in Peruvian gastric cancer strains than gastritis strains (9 of 14 versus 15 of 45, respectively; P = 0.04). Two ISHp608 types differing by approximately 11% in DNA sequence were identified: one was widely distributed geographically, and the other was found only in Peruvian and Alaskan strains. Isolates of a given type differed by < or = 2% in DNA sequence, but several recombinant elements were also found. ISHp608 marked with a resistance gene was found to (i) transpose in Escherichia coli; (ii) generate simple insertions during transposition, not cointegrates; (iii) insert downstream of the motif 5"-TTAC without duplicating target sequences; and (iv) require orfA but not orfB for its transposition. ISHp608 represents a widespread family of novel chimeric mobile DNA elements whose further analysis should provide new insights into transposition mechanisms and into microbial population genetic structure and genome evolution.     

Differences in genotypes of Helicobacter pylori from different human populations

DNA motifs at several informative loci in more than 500 strains of Helicobacter pylori from five continents were studied by PCR and sequencing to gain insights into the evolution of this gastric pathogen. Five types of deletion, insertion, and substitution motifs were found at the right end of the H. pylori cag pathogenicity island. Of the three most common motifs, type I predominated in Spaniards, native Peruvians, and Guatemalan Ladinos (mixed Amerindian-European ancestry) and also in native Africans and U.S. residents; type II predominated among Japanese and Chinese; and type III predominated in Indians from Calcutta. Sequences in the cagA gene and in vacAm1 type alleles of the vacuolating cytotoxin gene (vacA) of strains from native Peruvians were also more like those from Spaniards than those from Asians. These indications of relatedness of Latin American and Spanish strains, despite the closer genetic relatedness of Amerindian and Asian people themselves, lead us to suggest that H. pylori may have been brought to the New World by European conquerors and colonists about 500 years ago. This thinking, in turn, suggests that H. pylori infection might have become widespread in people quite recently in human evolution.     

The relationship between anthropometric indexes of adiposity and vascular function in the FATE cohort

Objective:

Numerous indexes of adiposity have been proposed and are currently in use in clinical practice and research. However, the correlation of these indexes with measures of vascular health remain poorly defined. This study investigated which measure of adiposity is most strongly associated with endothelial function.

Design and Methods:

Data from the Firefighters And Their Endothelium (FATE) study was used. The relationships between three measures of vascular function: flow‐mediated dilation (FMD), hyperemic velocity time integral (VTI), and hyperemic shear stress (HSS), and five measures of adiposity: BMI, waist circumference (WC), waist‐to‐hip ratio (WHR), waist‐to‐height ratio (WHtR), and body adiposity index (BAI) were tested. Univariate comparisons were made, and subsequently models adjusted for traditional risk factors were constructed.

Results:

A total of 1,462 male firefighters (mean age 49 ± 9) without cardiovascular disease comprised the study population. No measure of adiposity correlated with FMD; all five measures of adiposity were negatively correlated with VTI and HSS (P values <0.0001), with WHtR most strongly correlated with VTI, and WC most strongly correlated with HSS (both P < 0.05). In models including all five measures of obesity simultaneously, BMI, WC, and WHtR were all predictive of HSS (all P values <0.05), and BMI and WHR were both predictive of VTI (P values <0.05).

Conclusions:

Anthropometric measures of adiposity may help refine estimations of atherosclerotic burden. BMI was most consistently associated with endothelial dysfunction, but measures of adiposity that reflect distribution of mass were additive.     

Exosomal GAPDH from Proximal Tubule Cells Regulate ENaC Activity

Exosomes are nanometer-scale, cell-derived vesicles that contain various molecules including nucleic acids, proteins, and lipids. These vesicles can release their cargo into adjacent or distant cells and mediate intercellular communication and cellular function. Here we examined the regulation of epithelial sodium channels in mpkCCD cells and distal tubule Xenopus 2F3 cells by exosomes isolated from proximal tubule LLC-PK1 cells. Cultured mpkCCD cells were stained with CTX coupled to a green fluorophore in order to label the cell membranes and freshly isolated exosomes from LLC-PK1 cells were labeled with the red lipophilic dye PKH26 in order to visualize uptake of exosomes into the cells. Single-channel patch clamp recordings showed the open probability of ENaC in Xenopus 2F3 cells and in freshly isolated split-open tubules decreased in response to exogenous application of exosomes derived from LLC-PK1 proximal tubule cells. Active GAPDH was identified within exosomes derived from proximal tubule LLC-PK1 cells. The effect on ENaC activity in Xenopus 2F3 cells was blunted after application of exosomes transfected with the GAPDH inhibitor heptelidic acid. Also, we show GAPDH and ENaC subunits associate in mpkCCD cells. These studies examine a potential role for exosomes in the regulation of ENaC activity and examine a possible mechanism for communication from proximal tubule cells to distal tubule and collecting duct cells.     

A revisited phylogeography of Nautilus pompilius

The cephalopod genus Nautilus is considered a “living fossil” with a contested number of extant and extinct species, and a benthic lifestyle that limits movement of animals between isolated seamounts and landmasses in the Indo‐Pacific. Nautiluses are fished for their shells, most heavily in the Philippines, and these fisheries have little monitoring or regulation. Here, we evaluate the hypothesis that multiple species of Nautilus (e.g., N. belauensis, N. repertus and N. stenomphalus) are in fact one species with a diverse phenotypic and geologic range. Using mitochondrial markers, we show that nautiluses from the Philippines, eastern Australia (Great Barrier Reef), Vanuatu, American Samoa, and Fiji fall into distinct geographical clades. For phylogenetic analysis of species complexes across the range of nautilus, we included sequences of Nautilus pompilius and other Nautilus species from GenBank from localities sampled in this study and others. We found that specimens from Western Australia cluster with samples from the Philippines, suggesting that interbreeding may be occurring between those locations, or that there is limited genetic drift due to large effective population sizes. Intriguingly, our data also show that nautilus identified in other studies as N. belauensis, N. stenomphalus, or N. repertus are likely N. pompilius displaying a diversity of morphological characters, suggesting that there is significant phenotypic plasticity within N. pompilius.