Low cost, low tech SNP genotyping tools for resource-limited areas: Plague in Madagascar as a model

Genetic analysis of pathogenic organisms is a useful tool for linking human cases together and/or to potential environmental sources. The resulting data can also provide information on evolutionary patterns within a targeted species and phenotypic traits. However, the instruments often used to generate genotyping data, such as single nucleotide polymorphisms (SNPs), can be expensive and sometimes require advanced technologies to implement. This places many genotyping tools out of reach for laboratories that do not specialize in genetic studies and/or lack the requisite financial and technological resources. To address this issue, we developed a low cost and low tech genotyping system, termed agarose-MAMA, which combines traditional PCR and agarose gel electrophoresis to target phylogenetically informative SNPs

Parental diet, pregnancy outcomes and offspring health:metabolic determinants in developing oocytes and embryos

The periconceptional period, embracing the terminal stages of oocyte growth and post-fertilisation development up to implantation, is sensitive to parental nutrition. Deficiencies or excesses in a range of macro- and micronutrients during this period can lead to impairments in fertility, fetal development and long-term offspring health. Obesity and genotype-related differences in regional adiposity are associated with impaired liver function and insulin resistance, and contribute to fatty acid-mediated impairments in sperm viability and oocyte and embryo quality, all of which are associated with endoplasmic reticulum stress and compromised fertility. Disturbances to maternal protein metabolism can elevate ammonium concentrations in reproductive tissues and disturb embryo and fetal development. Associated with this are disturbances to one-carbon metabolism, which can lead to epigenetic modifications to DNA and associated proteins in offspring that are both insulin resistant and hypertensive. Many enzymes involved in epigenetic gene regulation use metabolic cosubstrates (e.g. acetyl CoA and S-adenosyl methionine) to modify DNA and associated proteins, and so act as 'metabolic sensors' providing a link between parental nutritional status and gene regulation. Separate to their genomic contribution, spermatozoa can also influence embryo development via direct interactions with the egg and by seminal plasma components that act on oviductal and uterine tissues

French shore

french aThis French shore, which is nearly one-half of the whole coast-line of Newfoundland, extends, as has been mentioned before, from Cape St. John on the north-east to Cape Ray on the south-west . . .See cited quotationPRINTED ITEMG. M. Story MAR 1970JH 3/70Used I and SupUsed I and SupNot use

Assessing Durability and Safety of Permethrin Impregnated Uniforms Used by Outdoor Workers to Prevent Tick Bites after One Year of Use

Long lasting permethrin-impregnated (LLPI) clothing can retain permethrin and repel ticks for up to three months and without exceeding EPA-approved safe levels; however, little is known about longer term effects of wearing LLPI clothing. Here, permethrin content was measured in new forester pants soon after initial impregnation (Insect Shield) and again one year later after being repeatedly worn by foresters in the field. Urine samples were collected from foresters for biomonitoring of permethrin metabolites at multiple time intervals (pre-use, one-month, three-to-four-months, and one-year post-use). Lethality against nymphal Ixodes scapularis Say was measured in clothing after one year of wear by foresters. Furthermore, to test potential variability in permethrin impregnation of different batches of clothing, separate sets of clothing were anonymously sent to Insect Shield for permethrin treatment over a period of three months and permethrin was quantified. Results demonstrated 33% of participants\u27 pants had no measurable permethrin after one year of wear and permethrin content and tick mortality varied significantly between clothing. Only two of the participants\u27 clothing resulted in ≥ 30% tick mortality after one year of wear. Significant differences were observed in 3-PBA and trans-DCCA, but not cis-DCCA metabolites in participants over the four measured time points and were higher than general United States population levels. This study provides practical information on the safety (measured by urinary metabolites) over time of LLPI clothing. It also provides snapshots (pre-washing and after one year of wear) of effectiveness of LLPI clothing as personal protective equipment against ticks for outdoor workers

Summary of parameter values, rodent host sub-model.

Summary of parameter values, rodent host sub-model.</p

Temporal distribution of the occurrence of partial and complete blockage in <i>O</i>. <i>montana</i> fleas following a single infectious blood meal containing 5 to 8 x 10⁸ <i>Y</i>.

pestis/ml in mouse or rat blood. The cumulative numbers from the three experiments using mouse blood (A) and two experiments using rat blood (B) are shown; see Table 1 for details.</p

The number of <i>Y</i>. <i>pestis</i> CFU transmitted by individual <i>O</i>. <i>montana</i> fleas 2 to 4 days after infection (early-phase) and after the development of partial or complete proventricular blockage.

Cumulative results from three experiments using mouse blood (blue symbols), two experiments using rat blood (red symbols), and two experiments using rat blood and the Y. pestis ΔhmsH mutant strain (open circles) are shown (see Table 1 for details); bars indicate the median number of Y. pestis transmitted per individual flea bite. The transmission probability (number of positive transmissions divided by the total number of trials) is indicated. All early-phase fleas were confirmed to have been infected when they fed for the transmission test. For both the partially blocked and blocked groups, differences in transmission probability and the number of CFU transmitted by fleas infected using mouse blood or rat blood were not statistically significant.</p

Fig 4 -

(A) Frequency distribution histogram of the numbers of Y. pestis CFU transmitted by individual O. montana fleas during the early phase (EPT) and by partially blocked (PB) and completely blocked (B) fleas. (B) Temporal distribution pattern of the number of CFU transmitted by individual partially blocked (PB) and completely blocked (B) fleas (positive transmission events only). Lines connecting data points indicate transmissions by the same flea on successive days. Cumulative results from three experiments using mouse blood (blue symbols) and two experiments using rat blood (red symbols) are shown; see Table 1 for details.</p

Model predictions of the incidence of infected-dead (% mortality) and infected-recovered (% recovered) hosts in populations with different levels of susceptibility [lethal dose (LD) of 1, 10, or 100 <i>Y</i>. <i>pestis</i> CFU].

Separate outcomes produced by fleas infected using mouse blood or rat blood in which both early-phase transmission and biofilm-dependent transmission by partially and completely blocked fleas are operative (All Tx); or in which only early-phase transmission (EPT only) or only biofilm-dependent transmission (B/PB only) are operative are indicated. All simulations were initiated with 9 susceptible hosts, 1 infected (highly bacteremic) host, and 50 uninfected fleas, monitored over a 100-day period. The results from two versions of the model using (A) unmodified parameters and (B) modified parameters for probability of transmission (p) and probability of transmission at or above a lethal dose (t) that account for cumulative transmission by simultaneous flea bites (S1 and S2 Figs). See text for details.</p

Infection and blockage rates of <i>O</i>. <i>montana</i> fleas during a four-week period following a blood meal containing 5 to 8 x 10⁸ <i>Y</i>. <i>pestis</i>/ml in mouse blood (blue symbols) or rat blood (red symbols).

(A) The percentage of fleas still infected and (B) the bacterial load per infected flea at different times after infection. (C) The percentage of fleas that developed partial or complete proventricular blockage during the four-week period. The mean and range of three independent experiments using mouse blood and two experiments using rat blood (Table 1) are indicated.</p