End group labelling of RNA and double stranded DNA by phosphate exchange catalyzed by bacteriophage T4 induced polynucleotide kinase.

End group labelling of sheared double-stranded DNA, and tRNA has been effected without prior dephosphorylation, utilizing the reversal of T₄ polynucleotide kinase activity. Incubation of DNA with polynucleotide kinase in the presence and absence of a phosphate acceptor (ADP) allowed the determination of the relative ratio of 5′ hydroxyl and 5′ phosphoryl terminii in the polynucleotide. This method of analysis has demonstrated a high preference in the formation of 5′ vs 3′ phosphomonoesters during high pressure shearing of double stranded DNA.     

Nestling development and the timing of tick attachments

Parasites exposed to fast-developing hosts experience a variety of conditions over a short time period. Only few studies in vertebrate-ectoparasite systems have integrated the timing of ectoparasite infestations in the host's development into the search for factors explaining ectoparasite burden. In this study we examined the temporal pattern of attachment in a nidicolous tick (Ixodes arboricola) throughout the development of a songbird (Parus major). In the first experiment, we exposed bird clutches at hatching to a mix of the 3 tick instars (larvae, nymphs and adults), and monitored the ticks that attached in relation to the average broods' age. In a complementary experiment we focused on the attachment in adult female ticks--the largest and most significant instar for the species' reproduction--after releasing them at different moments in the nestlings' development. Our observations revealed a positive association between the size of the attached instar and the broods' age. Particularly, adult females were less likely to be found attached to recently hatched nestlings, which contrasts with the smaller-sized larvae and nymphs. These differences suggest either an infestation strategy that is adapted to host physiology and development, or a result of selection by the hosts' anti-tick resistance mechanisms. We discuss the implications of our results in terms of tick life-history strategies.     

Intercalation of daunomycin into d(CG)4 oligomer duplex containing G x T mismatches by vibrational circular dichroism and infrared absorption spectroscopy

The vibrational circular dichroism (VCD) and infrared absorption (IR) spectra of the mismatched octamer oligonucleotides d(CGTGCGCG)(2) (CGT) and d(CGCGTGCG)(2) (CGC) and their complexes with the antitumor drug daunomycin were measured in D(2)O, interpreted, and compared to the octamer d(CGCGCGCG)(2) (CG). The IR spectra of the mismatched octamers in the carbonyl-stretching region are similar to those of the parent CG, whereas the VCD spectra differ in several respects between each other. The main VCD feature due to carbonyl stretching is informative for the mismatches and CG. Vibrational modes in the sugar-phosphate region remain essentially unchanged especially for PO(2) (-) symmetric stretching. Differences between the free and complexed mismatch octamers occurred mainly in the carbonyl-stretching region (1,700-1,600 cm(-1)). The absorption intensity of the C==O peak of G is more prominent for CGC than CGT and resembles CG in this respect. The detailed composition of this doublet is clearly visible, indicating the geometric rearrangement of the base pairs in the presence of the mismatch and upon forming the daunomycin complex.     

Translationally controlled tumor protein from Madurella mycetomatis, a marker for tumorous mycetoma progression

About 40 years ago Abs against the fungus Madurella mycetomatis were first demonstrated to be present in eumycetoma patients, a disease characterized by tumorous swellings. To date nothing is known about the individual immunoreactive Ags present in this fungus. In the present study, we identify its first immunogenic Ag, a protein homologous to the translationally controlled tumor protein (TCTP), a well-conserved histamine release factor in a range of eukaryotes. The gene for this Ag was demonstrated to be present in two variants in M. mycetomatis, with 13% aa difference between the two proteins encoded. In vitro, TCTP was secreted into the culture medium. In vivo, it was found to be expressed on hyphae present in developing stages of the eumycetoma-characteristic black grain. Significant IgG and IgM immune responses, against the whole protein and selected M. mycetomatis-specific peptides, were determined. The Ab levels correlated with lesion size and disease duration. Overall, the patients with the largest lesions had the highest Ab level, which lowered with decreasing size of the lesion. After 6-15 years of disease duration the Ab levels were the highest. TCTP is the first well-characterized immunogenic Ag, simultaneously the first monomolecular vaccine candidate, identified for the fungus M. mycetomatis.     

Vibrational circular dichroism signature of hemiprotonated intercalated four-stranded i-DNA

The four-stranded intercalated DNA structure exemplified by the oligonucleotide 5'-d(CCCCCCCCCCCC) (d(C)12) was studied at acidic pH by infrared absorption (IR) and vibrational circular dichroism (VCD) spectroscopy and compared with spectra of the same oligonucleotide at neutral pH to establish distinct VCD markers for the intercalation motif. The most striking feature is a new absorption at 1694 cm(-1) and its corresponding VCD couplet with reversed sign. These are unique for the intercalated structure and have not been observed for other parallel stranded duplexes. Significant characteristic features resulting from the spatial arrangement of the sugar-phosphate backbone are also clearly present for d(C)12 at acidic pH. An extensive network of CH...O bonds twists the backbone such that multiple through-space vibrational coupling occurs among neighbouring sugar-phosphate residues resulting in unusual VCD signals.     

Home ranges and survival of Nahan’s Francolin Francolinus nahani in Budongo Forest,Uganda

We studied home ranges, habitat use and survival of radio‐tagged Nahan’s Francolin in Budongo Forest Reserve, Uganda during July 1998–December 1999. We studied Nahan’s Francolin in an unlogged nature reserve, in a compartment logged in 1947–1952 and in a compartment logged twice, in 1963–1964 and 1996–1997. Mean home range was 14.22 ± 1.35 ha (n = 17). The home range was significantly larger in the nature reserve than in the recently logged compartment. Birds spent more time during the day in areas with high understorey vegetation density but preferred to roost and nest between buttresses of large trees. Understorey vegetation density and canopy openness were significantly greater in the logged forest than in the nature reserve. Annual survival of adult Nahan’s Francolins was 20.09 ± 7.33% (n = 23). Our results suggest that the maintenance of large trees and areas with high understorey vegetation density are both important for Nahan’s Francolin.     

Estimated cumulative incidence of pandemic (H1N1) influenza among pregnant women during the first wave of the 2009 pandemic

Background

Hospitalization and lab confirmed cases of H1N1 have been reported during the first wave of the 2009 pandemic but these are not accurate measures of influenza incidence in the population. We estimated the cumulative incidence of pandemic (H1N1) influenza among pregnant women in the province of Manitoba during the first wave of the 2009 pandemic.

Methods

Two panels of stored frozen serum specimens collected for routine prenatal screening were randomly selected for testing before (March 2009, n = 252) and after (August 2009, n = 296) the first wave of the pandemic. A standard hemagglutination inhibition assay was used to detect the presence of IgG antibodies against the pandemic (H1N1) 2009 virus. The cumulative incidence of pandemic (H1N1) influenza was calculated as the difference between the point prevalence rates in the first and second panels.

Results

Of the specimens collected in March, 7.1% were positive for the IgG antibodies (serum antibody titre ≥ 1:40). The corresponding prevalence was 15.7% among the specimens collected in August. The difference indicated a cumulative incidence of 8.6% (95% confidence interval [CI] 3.2%–13.7%). The rate differed geographically, the highest being in the northern regions (20.8%, 95% CI 7.9%–31.8%), as compared with 4.0% (95% CI 0.0%–11.9%) in Winnipeg and 8.9% (95% CI 0.0%–18.8%) in the rest of the province.

Interpretation

We estimated that the cumulative incidence of pandemic (H1N1) influenza among pregnant women in Manitoba during the first wave of the 2009 pandemic was 8.6%. It was 20.8% in the northern regions of the province.During the first wave of the pandemic (H1N1) 2009, the province of Manitoba was more severely affected than almost any other Canadian province.¹ Pregnant women in particular had higher rates of laboratory-confirmed infection and of severe illness.² However, the number of laboratory-confirmed cases is not an accurate measure of the incidence of influenza in the population. The number and geographic distribution of confirmed cases are influenced by differences in access to medical care, physicians’ practices and other factors.³We estimated the cumulative incidence of pandemic (H1N1) influenza among pregnant women in the province of Manitoba during the first wave of the 2009 pandemic. We did this by measuring the point seroprevalence in random samples of pregnant women presenting for routine prenatal screening before and after the first wave.