bluuebunny/crossref_metadata_2025 huggingface dataset:
Rangewide molecular structuring in the Utah sucker (Catostomus ardens)
Authors: MOCK K. E. , EVANS R. P. , CRAWFORD M. , CARDALL B. L. , JANECKE S. U. , MILLER M. P.
Published: May 2006

The Utah sucker (Catostomus ardens) is endemic to the Bonneville Basin and the upper Snake River drainage in western North America, and is thought to hybridize with the federally endangered June sucker (Chasmistes liorus mictus) in Utah Lake (Bonneville Basin). Here we describe the discovery of a major subdivision in Utah suckers (4.5% mitochondrial sequence divergence) between the ancient Snake River drainage and the Bonneville Basin. This boundary has not previously been recognized in Utah suckers based on morphologic variation, but has been recently described in two endemic cyprinids in the region. Populations in valleys east of the Wasatch Mountains in Utah clustered with the Snake River populations, suggesting that these valleys may have had an ancient hydrologic connection to the Snake River. We also found evidence of population isolation within the Bonneville Basin, corresponding to two Pleistocene sub‐basins of the ancient Lake Bonneville. In contrast, we found no molecular evidence for deep divergence between Utah suckers and June suckers in Utah Lake or for a history of hybridization between divergent lineages in that population, although we recognize that demographic events may have obscured this signal. These findings suggest that the morphological differences between Utah and June suckers in Utah Lake may be the result of strong, and relatively recent, ecological selection. In summary, morphological and molecular characters seem to vary along different axes in different portions of the range of this taxon, providing an interesting system for studying the contributions of neutral and adaptive variation to species diversity.
Evolutionary relationships of Drosophila mojavensis geographic host races and their sister species Drosophila arizonae
Authors: REED L. K. , NYBOER M. , MARKOW T. A.
Published: May 2006

The cactophilic Drosophila mojavensis species group living in the deserts and dry tropical forests of the southwestern United States and Mexico provides a valuable system for studies in diversification and speciation. Rigorous studies of the relationships between host races of D. mojavensis and the relationships among the members of the species group (D. mojavensis, Drosophila arizona, and Drosophila navojoa) are lacking. We used mitochondrial CO1 sequence data to address the phylogenetics and population genetics of this species group. In this study we have found that the sister species D. mojavensis and D. arizonae share no mitochondrial haplotypes and thus show no evidence for recent introgression. We estimate the divergence time between D. mojavensis and D. arizonae to be between 1.91 and 2.97 million years ago. D. arizonae shows little structure in our population genetic analyses but there is phylogenetic differentiation between southeastern and northern populations of D. arizonae. Drosophila mojavensis shows significant population and phylogenetic structure across the four geographic regions of its distribution. The mitochondrial data support an origin of D. mojavensis on the mainland with early differentiation into the populations now found in the Mojave Desert and the Mainland Sonoran Desert and later colonization of the Baja Peninsula, in contrast to previous models. Also, the sister clade to D. mojavensis/D. arizonae includes D. navojoa and Drosophila huaylasi. By defining the genetic relationships among these populations, we provide a foundation for more sophisticated hypothesis testing regarding the timing of early speciation events and host switches in this species group.
Bacteriophage WO‐B andWolbachiain natural mosquito hosts: infection incidence, transmission mode and relative density
Authors: CHAUVATCHARIN N. , AHANTARIG A. , BAIMAI V. , KITTAYAPONG P.
Published: May 2006

Bacteriophages ofWolbachiabacteria have been proposed as a potential transformation tool for genetically modifying mosquito vectors. In this study, we report the presence of the WO‐B class ofWolbachia‐associated phages among natural populations of several mosquito hosts. Eighty‐eight percent (22/25) ofWolbachia‐infected mosquito species surveyed were found to contain WO‐B phages. WO‐B phageorf7sequence analysis suggested that a single strain of WO‐B phage was found in most singly (23/24) or doubly (1/1)Wolbachia‐infected mosquitoes. However, the singleWolbachiastrain infectingAedes perplexuswas found to harbour at least two different WO‐B phages. Phylogenetic analysis suggested that horizontal transmission of WO‐B phages has occurred on an evolutionary scale between theWolbachiaresiding in mosquitoes. On an ecological scale, a low trend of co‐transmission occurred among specific WO‐B phages withinWolbachiaof each mosquito species. Assessment of the density of WO‐B phage by real‐time quantitative polymerase chain reaction (RTQ‐PCR) revealed an average relative density of 7.76 × 105± 1.61 × 105orf7copies per individual mosquito for a singleWolbachiastrain infecting mosquitoes, but a threefold higher density in the doublyWolbachia‐infectedAedes albopictus. However, the average combined density of WO‐B phage(s) did not correlate with that of theirWolbachiahosts, which varied in different mosquito species. We also confirmed the presence of WO‐B‐like virus particles in the laboratory colony ofAe. albopictus(KLPP) morphologically, by transmission electron microscopy (TEM). The viral‐like particles were detected after purification and filtration ofAe. albopictusovary extract, suggesting that at least one WO‐B‐like phage is active (temperate) within theWolbachiaof this mosquito vector. Nevertheless, the idea of utilizing these bacteriophages as transformation vectors still needs more investigation and is likely to be unfeasible.
Effects of Pleistocene glaciations on population structure of North American chestnut‐backed chickadees
Authors: BURG THERESA M. , GASTON ANTHONY J. , WINKER KEVIN , FRIESEN VICKI L.
Published: May 2006

The postglacial recolonization of northern North America was heavily influenced by the Pleistocene glaciation. In the Pacific Northwest, there are two disjunct regions of mesic temperate forest, one coastal and the other interior. The chestnut‐backed chickadee is one of the species associated with this distinctive ecosystem. Using seven microsatellite markers we found evidence of population structure among nine populations of chestnut‐backed chickadees. High levels of allelic variation were found in each of the populations. Northern British Columbia and central Alaska populations contained a large number of private alleles compared to other populations, including those from unglaciated regions. The disjunct population in the interior was genetically distinct from the coastal population. Genetic and historical records indicate that the interior population originated from postglacial inland dispersal. Population structuring was found within the continuous coastal population, among which the peripheral populations, specifically those on the Queen Charlotte Islands and the central Alaska mainland, were genetically distinct. The pattern of population structure among contemporary chickadee populations is consistent with a pioneer model of recolonization. The persistence of genetic structure in western North American chestnut‐backed chickadees may be aided by their sedentary behaviour, linear distribution, and dependence on cedar–hemlock forests.
Loss of both Holliday junction processing pathways is synthetically lethal in the presence of gonococcal pilin antigenic variation
Authors: Sechman Eric V. , Kline Kimberly A. , Seifert H. Steven
Published: May 2006

The obligate human pathogen Neisseria gonorrhoeae (Gc) has co‐opted conserved recombination pathways to achieve immune evasion by way of antigenic variation (Av). We show that both the RuvABC and RecG Holliday junction (HJ) processing pathways are required for recombinational repair, each can act during genetic transfer, and both are required for pilin Av. Analysis of double mutants shows that either the RecG or RuvAB HJ processing pathway must be functional for normal growth of Gc when RecA is expressed. HJ processing‐deficient survivors of RecA expression are enriched for non‐piliated bacteria that carry large deletions of the pilE gene. Mutations that prevent pilin variation such as recO, recQ, and a cis‐acting pilE transposon insertion all rescue the RecA‐dependent growth inhibition of a HJ processing‐deficient strain. These results show that pilin Av produces a recombination intermediate that must be processed by either one of the HJ pathways to retain viability, but requires both HJ processing pathways to yield pilin variants. The need for diversity generation through frequent recombination reactions creates a situation where the HJ processing machinery is essential for growth and presents a possible target for novel antimicrobials against gonorrhoea.
ppGpp with DksA controls gene expression in the locus of enterocyte effacement (LEE) pathogenicity island of enterohaemorrhagic Escherichia coli through activation of two virulence regulatory genes
Authors: Nakanishi Noriko , Abe Hiroyuki , Ogura Yoshitoshi , Hayashi Tetsuya , Tashiro Kosuke , Kuhara Satoru , Sugimoto Nakaba , Tobe Toru
Published: May 2006

For a new pathogen to emerge, it must acquire both virulence genes and a system for responding to changes in environmental conditions. Starvation of nutrients or growth arrest induces the stringent response in Escherichia coli, via increased ppGpp. We found the adherence capacity of enterohaemorrhagic E. coli (EHEC) and gene expression in the locus of enterocyte effacement (LEE) were enhanced by a downshift in nutrients or by entry into the stationary growth phase, both of which increase the ppGpp concentration. The activation was dependent on relA and spoT, which encode enzymes for the synthesis and degradation of ppGpp, and on dksA, which encodes an RNA polymerase accessory protein required for the stringent response. Upon induction of RelA expression, LEE gene transcription was activated within 20 min, even without starvation. The expression of two LEE transcriptional regulators, Ler and Pch, was activated by ppGpp and essential for the enhancement of LEE gene expression. In addition, the ler and pch promoters were directly activated by ppGpp in an in vitro transcription system. These findings suggest that the regulation of virulence genes in EHEC is integrated with E. coli's stringent response system, through the regulation of virulence regulatory genes.
Ruminal Drinkers: Endocrine and Metabolic Status and Effects of Suckling from a Nipple Instead of Drinking from a Bucket
Authors: Herrli‐Gygi M. , Hammon H. M. , Zbinden Y. , Steiner A. , Blum J. W.
Published: May 2006

In ruminal drinkers (RD) ingested milk is transported into the rumen and not into the abomasum. Because this is followed by changes in digestibility and absorption, we have tested whether this is associated with postprandial metabolic and endocrine changes. Unweaned, bucket‐fed calves (one RD, two controls) were studied on seven farms. On d 1, after metabolic and endocrine 12‐h profiles were studied, RD and one control calf were fed for 10 d by nipple, whereas the other control calf was fed by bucket. On d 11, metabolic and endocrine 12‐h profiles were again studied. On d 1, mean plasma concentrations of glucose, triglycerides, urea, insulin, insulin‐like growth factor‐1 (IGF‐1), 3,5,3′‐triiodothyronine (T3), thyroxine (T4) and leptin were significantly different between RD and controls, whereas mean concentrations of non‐esterified fatty acids (NEFA), total protein, albumin, and glucagon did not differ significantly among groups. In RD concentrations of glucose, NEFA, insulin, growth hormone, IGF‐1, and T4 were higher, and of urea were lower on d 11 than on d 1. Glucose and insulin concentrations increased postprandially in healthy calves on d 1, but barely in RD and remained lower than in controls, and there was no rise of NEFA and triglyceride concentrations on d 1 after the initial postprandial decrease in RD, in contrast to controls. But on d 11 postprandial responses of these four traits were similar in RD and controls and urea and T4 concentrations on d 11 became normalized. However, glucose and T3 concentrations in RD on d 11 were still lower than in one or both control groups. In conclusion, various metabolic and endocrine traits in RD differed from healthy controls. Drinking by floating nipple instead of drinking from bucket for 10 d normalized several metabolic and endocrine traits in RD.
Phenotypic and Genotypic Study of Gelatinase and β‐Haemolysis Activities in Faecal Enterococci of Poultry in Portugal
Authors: Poeta P. , Costa D. , Klibi N. , Rodrigues J. , Torres C.
Published: May 2006

The detection of gelatinase and β‐haemolysis activities was carried out in 83 faecal enterococci (43 Enterococcus faecalis, 33 E. faecium, five E. durans and two E. hirae) of poultry origin. In addition, the presence of genes of the gelE–fsrABC locus and of the cyl operon (cylLL, cylLS, cylA, cylB and cylM) were studied by polymerase chain reaction and correlated with gelatinase and β‐haemolysis production, respectively. Most of our E. faecalis isolates were gelatinase‐positive (88%), being this activity not frequent in the other enterococcal species (2.5%). Only one of the 33 E. faecium isolates showed a positive gelatinase reaction. All enterococci that showed gelatinase activity harboured the gelE and fsrABC genes, although these genes were also detected in four E. faecalis and one E. durans gelatinase‐negative isolates. Most of our non‐E. faecalis gelatinase‐negative isolates did not harbour gelE–fsrABC genes. A high proportion of faecal enterococci of poultry origin harboured genes of the cyl operon (71%), although only 7% contained the five cyl tested genes (all of them E. faecalis). Only one isolate of our series could express β‐haemolysis, harbouring the whole cyl operon. The cylLS genotype was the most prevalent in our enterococci (39%) and also the most prevalent among our E. faecalis isolates (60%). Other genotypes detected were the following ones (% of enterococci): cylA + cylB + cylM (13%), cylLL + cylA (4%), cylLL (4%), cylLL + cylA + cylB + cylM (2%), cylLL + cylA + cylM (1%) and cylA + cylM (1%). Both phenotypic and genotypic assays are important to evaluate the virulence potential of enterococci.
The Styrian Salmonella Monitoring Programme for Pork Production
Authors: Köfer J. , Kleb U. , Pless P.
Published: May 2006

The Styrian Salmonella Monitoring Programme for pork production is based on a representative analysis of the current status, serological meat juice monitoring and bacteriological tests of carcass halves and parts and has been in operation since 1999. A total of 34 170 meat juice samples from 3417 finisher herds were tested using the meat juice SALMOTYPE®‐ELISA (Labor Diagnostik, Leipzig, Germany) in the period from 1999 to 2003. More than 95% of the samples investigated were below the negative cut‐off of <20% based on the 5‐year average. The mean extinction values for meat juice samples showed regional differences, which were visualized for epidemiological purposes using the VETGIS® geographical information system (Department of Veterinary Administration, Graz, Austria). Salmonella spp. were detected in only 15 cases (0.13%) of a total of 11 330 bacteriologically tested wipe samples from meat‐processing plants. The Salmonella isolates detected included four S. Typhimurium, two S. Enteritidis PT 4, five S. Infantis, one S. Bredeny, one S. Saintpaul, one S. Brenderup and one S. Livingstone isolates. The proportion of Salmonella‐contaminated pork in the total population estimated from the annual sample showed a falling tendency. It decreased from 0.48% (CI: 0.23 ≤ P ≤ 0.85) in 1999 to 0.14% (CI: 0.07 ≤ P ≤ 0.24) in 2003. The contamination of Styrian pork with Salmonella is extremely low and thus poses a negligible risk of infection to consumers.
Prevalence and Intensity of Infection ofCryptosporidiumspp. andGiardia duodenalisin Dairy Cattle in Galicia (NW Spain)
Authors: Castro‐Hermida J. A. , Carro‐Corral C. , González‐Warleta M. , Mezo M.
Published: May 2006

Faecal samples were collected from 734 cattle selected at random from 60 dairy farms in Galicia (NW Spain). The animals studied were classified into 12 age groups: <1 month (53); 1–5 months (30); 6–11 months (31); 12–16 months (72); 17–20 months (64); 21–24 months (96); 3 years (94); 4 years (74); 5 years (67); 6 years (67); 7–8 years (63) and 9–13 years (23). Oocysts ofCryptosporidiumspp. were identified in 104 animals (14.2%) distributed throughout all of the age groups and from 40 different farms (66.7%). The percentage of cattle infected ranged between 58.5% in calves <1 month and 7.9% in 7 to 8‐year‐old cows, i.e. the percentage of infection decreased significantly (P < 0.05) with increasing age. The intensity of infection in animals older than 1 month ranged between 10 and 5924 oocysts/g of faeces and there were no significant differences between the different groups. Cysts ofGiardia duodenaliswere identified in 221 animals (30.1%) from 56 farms (93.3%). The parasite was detected in all age groups, at rates of infection ranging between 21.8% (9–13 years) and 56.7% (1–5 months), although these differences were not statistically significant. The intensity of infection ranged between 7 and 15 412 cysts/g of faeces, with the number of cysts shed being significantly higher (P <  0.05) in calves <1 month than in calves aged 1–5 months. Significant associations between parasitisation byCryptosporidiumspp. orG. duodenalisand the consistency of the faeces were only found in calves aged <1 month and 1–5 months. Concurrent infections were more prevalent in the groups of calves of 1–5 months (23.3%) and 6–11 months (25.8%).
Monitoring of Classical Swine Fever in Wild Boar (Sus scrofa) in Slovenia
Authors: Vengust G. , Grom J. , Bidovec A. , Kramer M.
Published: May 2006

Classical swine fever (CSF) is a highly contagious multi‐systemic haemorrhagic viral disease of pigs. Not only domestic pigs, but also wild boar appear to play a crucial role in the epidemiology of CSF. Spleen (n = 739) and blood coagulum (n = 562) sampled from wild boars (Sus scrofa) shot in 2002, and serum samples from 746 wild boar shot in 2003 and 2004, were tested throughout Slovenia. In 2002, 17 samples were positive on enzyme‐linked immunosorbent assay (ELISA) test for antibodies against classical swine fever virus (CSFV). Positive ELISA test was confirmed by a virus neutralization test. All other samples were negative. This is the first report that describes the epidemiology of CSFV from 2002 on, and the monitoring of the wild boar population in Slovenia at present.
Investigations into the Prevention of Prenatal and Lactogenic Toxocara canis Infections in Puppies by Application of Moxidectin to the Pregnant Dog
Authors: Krämer F. , Hammerstein R. , Stoye M. , Epe C.
Published: May 2006

Aim of the investigation was to examine whether two administrations of moxidectin to pregnant dogs could prevent pre‐natal and lactogenic infections of puppies with reactivated Toxocara canis larvae. Four pregnant beagles, infected experimentally with 20 000 embryonated eggs of T. canis, were treated subcutaneously with 1 mg moxidectin per kg body weight on days 40 and 55 of pregnancy (5–13 days before parturition). One further dam and its puppies served as untreated control. Two applications of moxidectin completely prevented pre‐natal and lactogenic infections in the puppies. Neither intestinal stages nor somatic larvae were found in the dams or their corresponding puppies. All puppies and dams of the treatment group remained coproscopically negative until 42 days after parturition. The administration of moxidectin did not show any side effects in the dams. None of the puppies of the treated dams showed any pathological abnormalities. In the untreated dam one adult and 26 somatic larvae of T. canis were detected at necropsy. All puppies of the untreated dam showed a patent T. canis infection from day 28 post‐natum (p.n.); 296 pre‐adult and adult stages of T. canis were spontaneously eliminated and 51 intestinal stages and five somatic larvae of T. canis were recovered at necropsy. In contrast to the puppies of the treated dams all negative control puppies showed blood eosinophilia after parturition and elevated liver enzyme levels.
Prevalence and Pathogenicity ofCryptosporidium suisin Pre‐ and Post‐weaned Pigs
Authors: Vítovec J. , Hamadejová K. , Landová L. , Kváč M. , Květonˇová D. , Sak B.
Published: May 2006

A total of 4338 faecal samples, 135 of sows, 3368 of pre‐weaned and 835 of post‐weaned piglets from eight farms in South Bohemia, Czech Republic were collected and examined forCryptosporidiuminfection. No sow, but 5.7% pre‐weaned and 24.1% post‐weaned piglets were positive forCryptosporidiuminfection. No relationship was found between diarrhoea andCryptosporidiuminfection in any of the different age groups (pre‐ and post‐weaned piglets). Four piglets, which were sporadically shedding cryptosporidia in faeces, were necropsied. Neither clinical signs of diarrhoea nor macroscopical changes were found. Histologically, a moderate infection of cryptosporidia was detected in the glandular epithelium along the large intestine, with predisposition to the ansa centralis of the colon. No inflammatory response in the lamina propria was observed. Cryptosporidia were also commonly found in the glandular epithelium of submucosal lymphoglandular complexes in the colon.Cryptosporidiumisolates from all farms were identified asCryptosporidium suisusing molecular markers (SSU rRNA). All of theC. suisstrains obtained were larger [6.2 (6.0–6.8) × 5.5 (5.3–5.7) μm] than any isolate described so far [4.6 (4.4–4.9) × 4.2 (4.0–4.3) μm] and did not appear to be infective for neonatal BALB/c mice.
Immunization of Sows in an Integrated Pig‐breeding Herd using a Homologous Inactivated Salmonella Vaccine Decreases the Prevalence of Salmonella typhimurium Infection in the Offspring
Authors: Roesler U. , Heller P. , Waldmann K.‐H. , Truyen U. , Hensel A.
Published: May 2006

The efficacy of a homologous vaccination in preventing infection of suckling piglets with Salmonella (S.) Typhimurium was evaluated after an immunization of pregnant sows using an inactivated herd‐specific S. Typhimurium vaccine. Twenty‐five pregnant sows were vaccinated three times antepartum. The efficiency of this vaccine regime was assessed by comparison with a control group of 37 sows and their suckling piglets, which were daily treated with enrofloxacin from day 14 antepartum until the day of weaning. From the first day of life until day 142 post‐partum, faecal samples of the piglets were collected and analysed for Salmonella shedding. In parallel, systemic antibody responses were monitored using a whole cell‐based isotype‐specific enzyme‐linked immunosorbent assay (ELISA). The bacteriological investigation showed marked effects of vaccination. Salmonella Typhimurium could not be detected in any of the faecal samples of the piglets from the vaccinated sows. In contrast, the piglets of the group with long‐time antibiotic treatment shed salmonellae rating to 47.4% of the animals. Furthermore, the offspring from vaccinated sows showed significantly decreased antibody activities of immunoglobulin (Ig)A and IgG. These bacteriological and serological results indicate a significantly lower Salmonella prevalence in piglets of the vaccinated group. As this study shows, the presented strategy of vaccination of pregnant sows with an inactivated Salmonella vaccine seems to be a suitable measure in decreasing Salmonella prevalence in offspring of infected sows.
Antibody Response toMycoplasma hyopneumoniaeInfection in Vaccinated Pigs with or without Maternal Antibodies induced by Sow Vaccination
Authors: Martelli P. , Terreni M. , Guazzetti S. , Cavirani S.
Published: May 2006

Vaccination with bacterins is an important tool for the control ofMycoplasma hyopneumoniaeinfection of pigs. Because such vaccination often involves piglets that have suckledM. hyopneumoniaeantibody‐positive dams it is important to understand the effect of pre‐existing (passively acquired) antibody on vaccine‐induced immunity. To investigate this issue experimentally, 20 sows that were seronegative forM. hyopneumoniaewere selected from aM. hyopneumoniae‐infected herd and then randomly allocated to one of four treatment groups (five sows/group): Group A, vaccinated sows/vaccinated piglets; Group B, vaccinated sows/non‐vaccinated piglets; Group C, non‐vaccinated sows/vaccinated piglets; Group D, non‐vaccinated sows/non‐vaccinated piglets. Sows (Groups A and B) were vaccinated 14 days before farrowing and seroconverted within the next 14 days. Conversely, none of the non‐vaccinated sows was seropositive at farrowing. Piglets (Groups A and C) were vaccinated when they were 7 days of age. Regardless of treatments none of the piglets had any evidence of an active immune response until many of those of Groups A and C and a few of those of Groups B and D seroconverted after it had been shown that at least some pigs of all groups had been naturally infected with a field strain ofM. hyopneumoniae. This pattern of immune responsiveness (i.e. the collective results of Groups A, B, C and D) suggested that vaccination of pigs had primed their immune system for subsequent exposure toM. hyopneumoniae, and that passively acquired antibody had little or no effect on either a vaccine‐induced priming or a subsequent anamnestic response. According to the statistical analysis sow serological status did not interfere with the antibody response in early vaccinated piglets. In conclusion, the results pointed out that early vaccination of piglets may assistM. hyopneumoniaecontrol independently from the serological status of sows.
Concurrent exposure to thermal stress and oral Ag induces intestinal sensitization in the mouse by a mechanism of regulation of IL‐12 expression
Authors: Liu Tao , Wang Bin‐Quan , Wang Chang‐Sheng , Yang Ping‐Chang
Published: May 2006

The mechanism of food allergy remains unclear. The absorption of intact protein Ag into the intestinal tissue is a prerequisite in the development of intestinal sensitization. Previous studies indicate that thermal stress compromises the intestinal barrier function. Mice were concurrently exposed to thermal stress and oral Ag. Intestinal sensitivity, levels of serum‐specific IgE, IL‐4 and INF‐γ were assessed. Intestinal dendritic cell, Th1 and Th2 functions were determined. The mice that were treated with thermal stress and oral Ag showed high levels of serum Ag‐specific IgE, intestinal mast cell activation in response to oral Ag challenge, suppression of IL‐12 expression in the intestinal dendritic cells, inhibition of T‐bet expression and Th1 function and marked increases in (GATA)3 expression and Th2 function. Mice exposed to thermal stress alone or oral Ag alone did not show any signs of the intestinal sensitization. Pretreatment with IL‐12 inhibited the intestinal sensitization induced by the concurrent exposure to thermal stress and Ag gavage. We conclude that although Ag absorption is essential, Ag absorption alone is insufficient; other accessory factors that can disturb the local immune homeostasis are also required for the induction of intestinal sensitization. The present study illustrates that concurrent exposure to thermal stress and oral Ag can prove to be a factor in the induction of intestinal sensitization by a mechanism of regulating IL‐12 expression.
Induction of protective and therapeutic antitumour immunity using a novel tumour‐associated antigen‐specific DNA vaccine
Authors: Sun Wenxin , Qian Haili , Zhang Xueyan , Zhou Chunxia , Liang Xiao , Wang Dongmei , Fu Ming , Ma Wenbo , Zhang Shuren , Lin Chen
Published: May 2006

DNA vaccination has become an attractive immunization strategy against cancer. However, a major problem of DNA vaccination is its limited potency to be taken up by the antigen‐presenting cells. In contrast, loss of immunogenic epitopes of tumour cells has urged the development of vaccines against multiple epitopes. In this study, we developed a novel strategy for the APC to efficiently cross‐present a fusion tumour antigen, which contains both MHC class I‐restricted and class II‐restricted T‐cell epitopes from Her‐2/neu and p53 in a cognate manner. The N‐terminus of the fusion Her‐2/neu, p53 protein was linked to the sequence encoding for human secondary lymphoid‐tissue chemokine for secretion and chemokinesis, and the C‐terminus of the fusion protein was linked to a cell‐binding domain of IgG (Fc portion, the cell‐binding domain of IgG) for receptor‐mediated internalization. Here, we show that the introduction of fused‐gene DNA vaccine by gene gun reduced the size of established tumours and prolonged the lifespan of tumour‐bearing mice. Results show that this DNA vaccination strategy can broadly enhance the antigen‐specific cellular and humoral immune responses. This vaccine is capable of inducing adaptive immunity and may provide a novel, generic design for the development of therapeutic and preventive DNA vaccines.
Characterization of CD8+ T‐cell responses in HIV‐1‐exposed seronegative commercial sex workers from Nairobi, Kenya
Authors: Alimonti Judie B , Kimani Joshua , Matu Lucy , Wachihi Charles , Kaul Rupert , Plummer Francis A , Fowke Keith R
Published: May 2006

CD8+ T‐lymphocyte responses are crucial to the control of HIV‐1; therefore, studying the CD8+ immune response in a naturally resistant population could provide valuable insights into an effective anti‐HIV response in healthy uninfected individuals. Approximately 5–10% of the women in the Pumwani Commercial Sex Worker cohort in Nairobi, Kenya, have been highly exposed to HIV‐1 yet remain HIV‐IgG‐seronegative and HIV‐PCR negative (HIVES). As IFN‐γ production correlates to cytotoxic function, the CD8+ T‐lymphocyte IFN‐γ response to HIV p24 peptides was compared in HIVES and HIV‐infected (HIV+) individuals. Almost 40% of the HIVES had a CD8+ IFN‐γ+ response that was five times lower in magnitude than that of the HIV+ group. The breadth of the response in HIVES was very narrow and focused primarily on one peptide that is similar to the protective KK10 peptide. In the HIV+ group, low peripheral CD4+ counts negatively influenced the number of CD8+ cells producing IFN‐γ, which may undermine the ability to control HIV. Overall, many of the HIVES women possess a HIV‐1 p24‐specific CD8+ IFN‐γ response, providing evidence to the specificity needed for an effective HIV vaccine.
Sex‐dependent expression of seven housekeeping genes in rat liver
Authors: VERMA ASHISH S , SHAPIRO BERNARD H
Published: May 2006

Background and Aim:  Sexual differences in the transcript levels of various genes including the hepatic isoforms of cytochrome P450 have been extensively studied. Expression of these sexual dimorphic genes have been quantified by Northern blotting, nuclear run on assays and reverse transcriptase‐polymerase chain reaction (RT‐PCR) methods using numerous housekeeping genes to normalize results. Earlier reports apparently assumed that these internal controls were sex‐independent. We have studied sex differences in the expression levels of seven different commonly used housekeeping genes.

Method:  We have used quantitative and semiquantitative RT‐PCR to monitor the levels of hepatic mRNAs in intact and hypophysectomized male and female rats.

Results:  We have observed sex‐dependent expression of the commonly used housekeeping genes tubulin, cyclophilin, tyrosine aminotransferase, β‐actin, glyceraldehyde‐3‐phosphate dehydrogenase, 18S and one unconventional housekeeping gene, that is, hypoxia inducing factor‐1α, in the livers of intact male and female rats. With the exception of glyceraldehyde‐3‐phosphate dehydrogenase and 18S which were female‐predominant (P < 0.01), the five other genes were found to be expressed at significantly (P < 0.01) higher concentrations in the livers of intact male rats. Similar to findings in which hypophysectomy eliminates sexual dimorphisms in cytochromes P450 expression, of the five housekeeping genes examined, cylophilin, tyrosine aminotransferase, glyceraldehyde‐3‐phosphate dehydrogenase, β‐actin, and 18S, all lost their sex‐dependent expression following pituitary ablation.

Conclusion:  Our data suggest that expression levels of these commonly measured housekeeping genes (structural and metabolic) are not constant, but rather are directly or indirectly regulated by sex‐dependent hormones, compromising their application as normalizing controls.
Endoscopic transpapillary nasopancreatic drainage alone to treat pancreatic ascites and pleural effusion
Authors: BHASIN DEEPAK KUMAR , RANA SURINDER SINGH , SIYAD ISMAIL , PODDAR UJJAL , THAPA BABU RAM , SINHA SAROJ KANT , NAGI BIRINDER
Published: May 2006

Background:  Pancreatic ascites and pleural effusion are uncommon sequelae of pancreatitis and are associated with significant morbidity and mortality. Endoscopic decompression of the pancreatic duct through transpapillary stent or nasopancreatic drain (NPD) has shown encouraging results but the experience is limited. The aim of the present study was to evaluate the efficacy of endoscopic transpapillary nasopancreatic drainage in patients with pancreatic ascites and pleural effusion.

Methods:  Over a period of 9 years, 10 patients (eight male) with pancreatic ascites and/or pleural effusion with pancreatic duct disruption documented on pancreatogram were studied. After informed consent, endoscopic transpapillary NPD was placed. The end‐points were resolution of ascites and/or pleural effusion or need for surgery.

Results:  Of 10 patients (age range: 13 months−46 years), four patients had only ascites, four had only pleural effusion and two had both ascites and pleural effusion. Ascites and/or pleural effusion resolved in all the patients within 4 weeks of placement of NPD. The healing of ductal disruption was demonstrated by nasopancreatogram as early as 2 weeks and NPD could be removed without necessitating another endoscopy. No major complications related to NPD placement were noted. There was no recurrence of pancreatic ascites and/or pleural effusion at a mean follow up of 39 months.

Conclusions:  Pancreatic ascites and pleural effusion can be effectively treated by endoscopic retrograde pancreatography and transpapillary NPD placement.
Peliosis hepatis in a living related liver transplantation donor candidate
Authors: Testa Giuliano , Panaro Fabrizio , Sankary Howard , Chejfec Gregorio , Mohanty Smruti , Benedetti Enrico , Layden Thomas
Published: May 2006

Peliosis hepatis is a rare benign condition histologically characterized by multiple cystic blood‐filled spaces distributed throughout the liver parenchyma. Peliosis hepatis has been associated with malignancies, immunosuppression, infections and medications. We report a case of peliosis hepatis in a candidate for living liver donation, which regressed with restitutio ad integrum, after the noxious stimulus was stopped. We conclude that after diagnosis of peliosis hepatis is established and its cause is removed, simple radiographic imaging is sufficient to document the restitutio ad integrum of the parenchyma, avoiding repeat histological confirmation.
Efficacy of peppermint oil as an antispasmodic during endoscopic retrograde cholangiopancreatography
Authors: Yamamoto Natsuyo , Nakai Yousuke , Sasahira Naoki , Hirano Kenji , Tsujino Takeshi , Isayama Hiroyuki , Komatsu Yutaka , Tada Mimoru , Yoshida Haruhiko , Kawabe Takao , Hiki Naoki , Kaminishi Michio , Kurosaka Hanzo , Omata Masao
Published: May 2006

Background:  During endoscopic retrograde cholangiopancreatography (ERCP), hyoscine‐N‐butylbromide (Buscopan) or glucagon is used to inhibit duodenal motility. However, they may cause adverse effects. Peppermint oil has an antispasmodic effect and is used as a less hazardous antispasmodic during colonoscopy and upper gastrointestinal endoscopy. The purpose of the present paper was therefore to investigate peppermint as an antispasmodic for ERCP.

Methods:  Forty patients were enrolled prospectively. They were assigned to four groups according to the peppermint oil concentration and site of administration: group 1, 20 mL of 1.6% solution around duodenal papilla; group 2, 20 mL of 1.6% solution both to the antrum of the stomach and around the duodenal papilla; group 3, 20 mL of 3.2% solution around the duodenal papilla; and group 4, 3.2% solution both to the antrum and around the duodenal papilla. Glucagon or hyoscine‐N‐butylbromide was added when duodenal peristalsis was not adequately diminished. Sixteen patients undergoing ERCP with glucagon were employed as historical controls.

Results:  The ERCP was attempted in all except one patient in group 2 who had bleeding from invaded tumor to the duodenum. Peppermint administration equally reduced duodenal motility in the groups. Duodenal movement was none or mild in 69.2% of patients. The ERCP was successfully performed with peppermint alone in 91.4% of patients (37/39). Glucagon or hyoscine‐N‐butylbromide was needed in one patient each in groups 1 and 4. Serious complications related to peppermint oil did not occur. Inhibitory effect of peppermint appears to be identical to that of glucagon.

Conclusion:  Duodenal relaxation was obtained with 20 mL of 1.6% peppermint oil solution in the duodenum, but additional administration may be required. Peppermint oil is useful as an antispasmodic agent for ERCP.
Gastroesophageal reflux disease in Asian countries: Disorder of nature or nurture?
Authors: Ho Khek Yu , Cheung Ting Kin , Wong Benjamin Cy
Published: May 2006

Gastroesophageal reflux disease (GERD) is less prevalent in Asia than in the West, but there is now evidence to suggest that its frequency is rapidly rising in Asia. The different prevalence rates reported in various Asian studies may represent different points in the ‘rising’ phase of GERD. The cause for the lower but increasing prevalence of GERD in Asia is not known, but genetics and to some extent environmental factors, may have initially protected Asians against GERD. However, with the recent globalization of economies, the associated lifestyle changes in many developing Asian countries may have tipped the balance in favor of the development of GERD.
Effect of oral esomeprazole on recurrent bleeding after endoscopic treatment of bleeding peptic ulcers
Authors: Wei Kou‐Liang , Tung Shui‐Yi , Sheen Cheng‐Han , Chang Te‐Shen , Lee I‐Lin , Wu Cheng‐Shyong
Published: May 2006

Background:  After endoscopic treatment of bleeding peptic ulcer, a high‐dose infusion of omeprazole substantially reduces the risk of recurrent bleeding. The role of oral proton pump inhibitors for these patients is uncertain. The purpose of the present study was to assess whether the use of oral esomeprazole would reduce the frequency of recurrent bleeding after endoscopic treatment of bleeding peptic ulcers.

Methods:  Patients with actively bleeding ulcers or ulcers with non‐bleeding visible vessels were treated with an epinephrine injection followed by thermocoagulation. After hemostasis had been achieved, they were randomly assigned in a double‐blind fashion to receive esomeprazole (40 mg p.o. twice daily for 3 days) or placebo. The outcome measures studied were recurrent bleeding, blood transfusion requirement, surgery and death.

Results:  A total of 70 patients were enrolled, 35 in each group. Bleeding recurred within 30 days in two patients (5.7%) in the esomeprazole group, as compared with three (8.6%) in the placebo group (P = 0.999). Blood transfusion requirement was 2.8 ± 1.4 units in the esomeprazole group and 2.7 ± 1.3 units in the placebo group (P = 0.761). Duration of hospitalization was 4.82 ± 1.8 days in the esomeprazole group and 4.58 ± 2.7 days in the placebo group (P = 0.792). No patients needed surgery for control of bleeding and no patients died in both groups.

Conclusions:  After successful endoscopic treatment of bleeding peptic ulcer, oral use of esomeprazole might offer no additional benefit on the risk of recurrent bleeding.
Metabolic factors involved in the therapeutic response of patients with hepatitis C virus‐related chronic hepatitis
Authors: Tarantino Giovanni , Conca Paolo , Sorrentino Paolo , Ariello Manuela
Published: May 2006

Background:  The purpose of the present paper was to investigate the factors possibly involved in the failure of pegylated interferon (Peg IFN) plus ribavirin treatment at standard dosage in hepatitis C virus (HCV) 1b patients, with chronic hepatitis.

Methods:  A fully screened population of 40 virological non‐responders (NR) to combined antiviral therapy was selected and matched, 1:1, with a similar cohort of end‐therapy virological responders (R).

Results:  Waist circumference, glucose metabolic impairment, body mass index, non‐genetic iron overload, steatosis and fibrosis severity and, finally, arterial hypertension were statistically more frequent in the NR group on Peg IFN plus ribavirin. Increased waist circumference was the strong independent predictor of therapeutical failure. Interestingly, the concomitant presence of cofactors was more significantly represented in NR, whereas in the R cohort this association was found in a few cases only.

Conclusion:  Insulin‐resistance syndrome could contribute to non‐response in treated chronic HCV patients, suggesting the presence of dysmetabolic factors that frequently cluster in a critical combination.
Molecular epidemiology of hepatitis A virus in Brazilian Amazon
Authors: De Paula Vanessa Salete , Niel Christian , Teves Simone Caldas , Villar Lívia Melo , Virgolino Helaine , Gaspar Ana Maria Coimbra
Published: May 2006

Background:  Hepatitis A virus (HAV) is highly endemic in the Amazon. However, few data are available regarding HAV genotypes circulating in this region of the world. The aim of the present study was to characterize genetically HAV isolates circulating in the Brazilian part of the Amazon.

Methods:  Blood samples were collected from 134 IgM anti‐HAV positive patients (sporadic cases). Viral RNA was extracted and the virion protein (VP)1/2A junction region of the HAV genome was successfully amplified by reverse transcription–polymerase chain reaction for 81 samples (60.4%). Nucleotide sequences (210 bp) of the 81 isolates were determined.

Results:  All HAV samples were from genotype I, with 78 (96.3%) belonging to subgenotype IA and three (3.7%) to subgenotype IB. By phylogenetic analysis, it was shown that 72/78 of the subgenotype IA isolates formed a cluster separated from the other South American HAV isolates previously characterized.

Conclusion:  The present study provides valuable new data on the genetic relatedness of HAV from the Amazon. Subgenotype IB circulates in the Brazilian Amazon but the predominant genotype is 1A, similar to what occurs in most South American countries.
Increase of mast cells may be associated with infiltration of eosinophils and proliferation of microvessels in gastric eosinophilic granuloma
Authors: Li Xi , Gao Zhen‐Jun , Cao Ji‐Wang , Yu Bao‐Ping , Song Liu‐Lai , Luo He‐Sheng
Published: May 2006

Background:  Gastric eosinophilic granuloma (GEG) is a rare disease. Recently this disease has begun to increase in China. In the present study, the function and the role of mast cells (MC) in the pathogenesis of GEG were investigated.

Methods:  Paraffin‐embedded tissue sections from 23 GEG patients and 15 gastric ulcer (GU) patients, were stained with antihuman mast cell tryptase for counting the MC and degranulated MC. Antihuman CD34 antibody was used for detecting the microvessel density (MVD) with immunohistochemical technique. Mast cell degranulation was also studied using electron microscopy.

Results:  The quantity of both MC and degranulated MC were higher in both GEG and GU than in normal gastric mucosa. The proportion of degranulated MC was higher in the GEG but in GU it was similar to normal mucosa. The MVD was higher in both GU and GEG than that in the normal gastric mucosa and it was higher in the high‐MC group than in the low‐MC group in GEG. The positive correlation between eosinophil and MC was present only in GEG, not in GU.

Conclusions:  The infiltration of eosinophils and MVD may be associated with the increase of MC in GEG. This suggests that in addition to eosinophils, MC might be the important cells in the pathogenesis of GEG.
Clinical implications of matrix metalloproteinase‐1, ‐3, ‐7, ‐9, ‐12, and plasminogen activator inhibitor‐1 gene polymorphisms in colorectal cancer
Authors: Woo Mijung , Park Kyungsook , Nam Junghyun , Kim Jin C
Published: May 2006

Background and Aim:  Overexpression of matrix metalloproteinase (MMP)‐1, ‐3, ‐7, ‐9, and plasminogen activator inhibitor‐1 (PAI‐1) are implicated in the invasion and metastasis of colorectal cancer, while MMP‐12 provides a protective role against colorectal cancer. The promoter and exon polymorphisms of their genes, which are known to affect the transcription of these genes, were assessed to correlate with colorectal cancer susceptibility.

Methods:  MMP1, 3, 7, 9, 12 and PAI1 were assayed in 185 colorectal cancer patients and 304 healthy controls using polymerase chain reaction (PCR)‐restriction fragment length polymorphism (RFLP) analysis. Respective genotypes and haplotypes were compared between the population groups and also between clinicopathological characteristics in the colorectal cancer patients.

Results:  The homozygous MMP1‐1607*dupG genotype was significantly more frequent in colorectal cancer patients than in healthy controls. The frequency of MMP1‐1607*dupG homozygotes was also greater in patients of less than or equal to 50 years of age, and in patients with 10 or more metastatic lymph nodes, compared with those of older age or with fewer lymph nodes. The frequency of MMP9‐1562*C homozygotes was significantly greater in colorectal cancer patients than in healthy controls. However, the genotype and allele frequencies of MMP3‐1171dupA, MMP7‐181A > G, MMP12‐82A > G, MMP9‐90(CA)14−27, and R279Q did not differ between the population groups or clinicopathological parameters. The MMP7‐181A‐MMP1–1607dupG‐MMP3‐1171A‐MMP12‐82A and MMP9‐1562C‐90(CA)20+ 279Q haplotypes were significantly more frequent in colorectal cancer patients than in healthy controls. The genotype and allele frequencies of PAI1‐675*G were similar between patients and healthy controls, but the frequency of PAI1‐675*G homozygotes was significantly greater in patents over 50 years of age.

Conclusions:  MMP1‐1607*dupG and MMP9‐1562*C homozygotes demonstrated an increased risk of colorectal cancer regardless of ethnic differences, whereas other MMP and PAI1 polymorphisms did not. Nevertheless, specific MMP haplotypes on 11q22.1–23.3 and 20q12–13 seem to be implicated in susceptibility to colorectal cancer.