Asymptomatic Helicobacter pylori infection and iron deficiency are not associated with decreased growth among Alaska Native children aged 7-11 years

Introduction: Alaska Native children have high Helicobacter pylori infection and iron deficiency prevalences, and their average height‐for‐age is lower than US reference populations. During a clinical trial to determine the impact of H. pylori treatment on iron deficiency, we evaluated the effects of H. pylori infection and treatment on growth. Materials and Methods: We measured height and weight for children aged 7–11 years in western Alaska using village‐based measuring devices. H. pylori infection was determined by urea breath test and iron deficiency using serum ferritin. Children with H. pylori infection and iron deficiency entered the treatment phase and received iron alone or iron plus triple therapy for H. pylori. Follow‐up evaluations occurred at 2, 8, and 14 months. We evaluated the association between baseline H. pylori infection and growth; among children in the treatment phase, we also assessed the effect of H. pylori resolution on growth. Results: At baseline, 566 (87.1%) of 650 children were infected with H. pylori. Neither height and weight, nor body mass index differed by H. pylori infection status. Of 189 children in the treatment phase, 20 (10.6%) were uninfected at all three follow‐up periods, and 54 (28.6%) were uninfected for one or two periods. Compared with continuously infected children, children in these two groups had little evidence of improvements in any of the measured growth outcomes. Conclusions: H. pylori infection is not related to growth among Alaska Native children aged 7–11 years. Growth deficiency should not be considered an indication for H. pylori therapy.     

TRPM channels, calcium and redox sensors during innate immune responses

Melastatin-related TRPM ion channels have emerged as novel therapeutic targets due to their potential ability to modulate the function and fate of immune cells during inflammation, innate, and adaptive immunity. Four family members, TRPM1, TRPM2, TRPM4 and TRPM7 have a strong presence in the immune system. TRPM channels regulate ion-homeostasis by sensing cellular redox status and cytoplasmic calcium levels. TRPM2 for example, is highly expressed in phagocytes. This channel is activated by intracellular ADP-ribose upon exposure to oxidative stress and induces cell death. Here we will review the functional links between TRPM-mediated ion conductance, chemotaxis, apoptosis, and innate immunity.     

Effect of incubation temperature on isolation of Campylobacter jejuni genotypes from foodstuffs enriched in Preston broth

Preston broth and agar incubated at either 37 or 42 degrees C have been widely used to isolate campylobacters from foodstuffs. The consequences of using either incubation temperature were investigated. Retail packs of raw chicken (n = 24) and raw lamb liver (n = 30) were purchased. Samples were incubated in Preston broth at 37 and 42 degrees C and then streaked onto Preston agar and incubated as before. Two Campylobacter isolates per treatment were characterized. Poultry isolates were genotyped by random amplification of polymorphic DNA (RAPD), pulsed-field gel electrophoresis (PFGE), and flagellin PCR-restriction fragment length polymorphism, and lamb isolates were genotyped by RAPD only. In total, 96% of the poultry and 73% of the lamb samples yielded campylobacters. The lamb isolates were all Campylobacter jejuni, as were 96% of the poultry isolates, with the remainder being Campylobacter lari. The incubation temperature had no significant effect on the number of positive samples or on the species isolated. However, genotyping of the C. jejuni isolates revealed profound differences in the types obtained. Overall (from poultry and lamb), the use of a single incubation temperature, 37 degrees C, gave 56% of the total number of RAPD C. jejuni genotypes, and hence, 44% remained undetected. The effect was especially marked in the poultry samples, where incubation at 37 degrees C gave 47% of the PFGE genotypes but 53% were exclusively recovered after incubation at 42 degrees C. Thus, the incubation temperature of Preston media selects for certain genotypes of C. jejuni, and to detect the widest range, samples should be incubated at both 37 and 42 degrees C. Conversely, genotyping results arising from the use of a single incubation temperature should be interpreted with caution.     

Using municipal biosolids in combination with other residuals to restore metal-contaminated mining areas

High metal waste materials from historic mining at the Bunker Hill, Idaho (ID) Superfund site was amended with a range of materials including municipal biosolids, woody debris, wood ash, pulp and paper sludge, and compost. The existing soil or waste material has elevated metal concentrations with total Zn, Pb and Cd ranging from 6000 to 14700, 2100 to 27000 and 9 to 28 mg kg^–1, respectively. Surface application of certain amendments including biosolids mixed with wood ash resulted in significant decreases in subsoil acidity as well as subsoil extractable metals. This mixture was sufficient to restore a plant cover to the contaminated areas. At the Bunker Hill site, a surface application of high N biosolids (44 or 66 tons ha^–1) in combination with wood ash (220 tons ha^–1) with or without log yard debris (20% by volume) or pulp and paper sludge (44 tons ha^–1) was able to restore a vegetative cover to the metal contaminated materials for 2 years following amendment application. Plant biomass in 1999 was 0.01 mg ha^–1 in the control versus a mean of 3.4 tons ha^–1 in the residual amended plots. Metal concentrations of the vegetation indicated that plants were within normal concentrations for the 2 years that data were collected. Surface application of amendments was also able to reduce Ca(NO₃)₂ extractable Zn in the subsoil from about 50 mg kg^–1in the control to less than 4 mg kg^–1in two of the treatments. Use of conventional amendments including lime alone and microbial stimulants were not sufficient to support plant growth. These results indicate that surface application of biosolids in combination with other residuals is sufficient to restore a vegetative cover to high metal mine wastes.     

Pyroglutamyl-peptidase I: cloning,sequencing, and characterisation of the recombinant human enzyme

Pyroglutamyl-peptidase I (EC 3.4.19.3) is well known from bacteria and archaea, but has not previously been cloned or sequenced from any vertebrate. We describe the cloning and sequencing of the human (AJ278828) and mouse (AJ278829) forms of pyroglutamyl-peptidase I. The deduced amino acid sequences each consist of 209 residues and show approximately 30% identity with bacterial forms of the enzyme. They show clear homology to the enzyme from prokaryotes and place the mammalian forms of the enzyme in peptidase family C15 of the MEROPS database. The catalytic residues Glu81, Cys144, and His166 in the enzyme from Bacillus amyloliquefaciens are all conserved in the human sequence. A simple cartoon model of the human protein was constructed on the basis of the published crystal structures of pyroglutamyl-peptidase I forms from Thermococcus litoralis and B. amyloliquefaciens. The human enzyme was expressed by use of a baculovirus vector in Spodoptera frugiperda cells. The recombinant protein was enzymatically active and had properties similar to those described for the naturally occurring mammalian enzyme. Gel-filtration chromatography of the active enzyme gave a molecular mass of about 24kDa, showing that the enzyme is active as the monomer. This contrasted with indications that the prokaryotic enzymes may be tetrameric. Recombinant human pyroglutamyl-peptidase I was active on pGlu-aminomethylcoumarin in the range pH 6-9, with maximal activity being seen at pH 7.0-8.5; it showed an absolute requirement for a thiol-reducing agent. In crude preparations, the enzyme was completely stable for 90 min at 50 degrees C. The enzyme was inhibited by transition metal ions including Ni(2+), Zn(2+), and Cu(2+), and by sulfhydryl-blocking agents. Reversible inhibition was seen with 2-pyrrolidone (K(i)=50 microM), and surprisingly, with N-ethylmaleimide (K(i)=30 microM).     

Finger length and distal finger extent patterns in humans

The fingers in the adult human hand differ in length and in distal extent. The literature agrees that in the clear majority of males, the distal extent of the ring finger tends to be relatively greater (using the middle finger as standard) than the index finger. However, the results for females vary considerably, with some studies reporting that females show a similar pattern to that of males, while others suggest that the prevalence of a longer index finger is relatively or absolutely more common in females. We provide a review of the literature, and a set of data for both finger length and distal fingertip extent of the finger for a contemporary cohort of young adult females and males (n = 502). Finger length measures favor the ring finger of both sexes, with smaller between-finger differences for females than for males. However, while the distal fingertip extent favors the ring finger of both hands in males, in females the left hand shows no significant differences, and the right hand shows a small index finger advantage. Thus, the sexual dimorphism in finger measures is more strongly expressed in the distal extent of fingertips than in the length of fingers. The sex differences in distal fingertip extent derive from the index finger only, with a lesser distal extent of the index finger, relative to the middle finger, in males than in females.     

Glucocorticoid-induced apoptosis in early B cells from human bone marrow

The sensitivity of normal human lymphoid precursor cells to glucocorticoid-induced apoptosis is a subject of controversy. The in vitro response of cells of the B lineage (CD19(+)) from the marrow of 22 adult subjects to glucocorticoids was evaluated herein using both natural steroids and dexamethasone (Dex). When exposed to 1 micro M Dex, 32% of the subjects exhibited high losses of CD19(+) B cells in the range of 45%. The remaining subjects exhibited more modest losses in CD19(+) cells of 26%-40%. Surprisingly, cortisol, a naturally produced glucocorticoid, produced B lineage losses nearly equivalent to Dex, which reached maximum by 12 hr. It was subsequently noted that the variances in losses of CD19(+) cells among the subjects correlated closely with the proportion of early CD10(+) CD19(+) B cells present in the initial population. The latter cells exhibited a high degree of sensitivity to glucocorticoids, with losses of 60%-80% noted. Mature B cells bearing IgD, on the other hand, were fairly resistant to glucocorticoids. Merocyanine 540, a membrane dye that fluoresces in the disordered membrane of apoptotic cells, confirmed that early or progenitor B cells in human bone marrow were indeed undergoing glucocorticoid-induced apoptosis, which could be blocked by the glucocorticoid antagonist RU38486. These data provide evidence that human marrow B cells, especially early B-cell progenitors, are quite sensitive to glucocorticoids and readily undergo apoptosis within a few hours of exposure to the steroids.     

Superparasitism and sex ratio in the solitary parasitoidEpidinocarsis lopezi

Highly variable sex ratios are found in the solitary parasitoidEpidinocarsis lopezi, both in the field and in a mass-rearing situation. Superparasitism is one of a number of factors which can influence sex ratios in parasitoid Hymenoptera. We show that superparasitism inE. lopezi is common in the field. Sex allocation decisions when parasitizing unparasitized hosts are not different from those with parasitized hosts; neither does differential mortality occur between the sexes in superparasitized hosts. Therefore superparasitism does not contribute to the variable sex ratio ofE. lopezi. Both the occurrence of superparasitism and the sex produced when ovipositing are shown to be functional forE. lopezi.     

siRNA relieves chronic neuropathic pain

Double stranded, short interfering RNAs (siRNA) of 21–22 nt length initiate a sequence-specific, post-trancriptional gene silencing in animals and plants known as RNA interference (RNAi). Here we show that RNAi can block a pathophysiological pain response and provide relief from neuropathic pain in a rat disease model by down regulating an endogenous, neuronally expressed gene. Rats, intrathecally infused with a 21 nt siRNA perfectly complementary to the pain-related cation-channel P2X₃, showed diminished pain responses compared to missense (MS) siRNA-treated and untreated controls in models of both agonist-evoked pain and chronic neuropathic pain. This form of delivery caused no adverse effects in any of the animals receiving P2X₃ siRNA, MS siRNA or vehicle. Molecular analysis of tissues revealed that P2X₃ mRNA expressed in dorsal root ganglia, and P2X₃ protein translocated into the dorsal horn of the spinal cord, were significantly diminished. These observations open a path toward use of siRNA as a genetic tool for drug target validation in the mammalian central nervous system, as well as for proof of concept studies and as therapeutic agents in man.