bluuebunny/crossref_metadata_2025 huggingface dataset:
Geographic structure, genetic diversity and source tracking of Spartina alterniflora
Authors: Blum Michael J. , Jun Bando K. , Katz M. , Strong Donald R.
Published: August 2007

Aim  To examine the distribution and structure of genetic variation among native Spartina alterniflora and to characterize the evolutionary mechanisms underlying the success of non‐native S. alterniflora.

Location  Intertidal marshes along the Atlantic, Gulf and Pacific coasts of North America.

Methods  amova, parsimony analysis, haplotype networks of chloroplast DNA (cpDNA) sequences, neighbour‐joining analysis, Bayesian analysis of population structure, and individual assignment testing were used.

Results  Low levels of gene flow and geographic patterns of genetic variation were found among native S. alterniflora from the Atlantic and Gulf coasts of North America. The distribution of cpDNA haplotypes indicates that Atlantic coast S. alterniflora are subdivided into ‘northern’ and ‘southern’ groups. Variation observed at microsatellite loci further suggests that mid‐Atlantic S. alterniflora are differentiated from S. alterniflora found in southern Atlantic and New England coastal marshes. Comparisons between native populations on the Atlantic and Gulf coasts and non‐native Pacific coast populations substantiate prior studies demonstrating reciprocal interspecific hybridization in San Francisco Bay. Our results corroborate historical evidence that S. alterniflora was introduced into Willapa Bay from multiple source populations. However, we found that some Willapa Bay S. alterniflora are genetically divergent from putative sources, probably as a result of admixture following secondary contact among previously allopatric native populations. We further recovered evidence in support of models suggesting that S. alterniflora has secondarily spread within Washington State, from Willapa Bay to Grays Harbor.

Main conclusions  Underlying genetic structure has often been cited as a factor contributing to ecological variation of native S. alterniflora. Patterns of genetic structure within native S. alterniflora may be the result of environmental differences among biogeographical provinces, of migration barriers, or of responses to historical conditions. Interactions among these factors, rather than one single factor, may best explain the distribution of genetic variation among native S. alterniflora. Comprehensive genetic comparisons of native and introduced populations can illustrate how biological invasions may result from dramatically different underlying factors – some of which might otherwise go unrecognized. Demonstrating that invasions can result from several independent or interacting mechanisms is important for improving risk assessment and future forecasting. Further research on S. alterniflora not only may clarify what forces structure native populations, but also may improve the management of non‐native populations by enabling post‐introduction genetic changes and the rapid evolution of life‐history traits to be more successfully exploited.
Guild composition and mustelid morphology – character displacement but no character release
Authors: Meiri Shai , Dayan Tamar , Simberloff Daniel
Published: August 2007

Aim Competition is hypothesized to lead to the evolution of reduced morphological overlap between competitors. Within guilds, this is believed to lead to overdispersed size ratios of the trophic apparatus of adjacent‐sized species. In allopatry, conditions are believed to favour character release. We examined whether character displacement is prevalent in mainland musteline guilds and sought evidence for character release in adjacent island guilds.

Location Holarctic, from Japan through western Europe to Pacific North America.

Methods We measured skulls and canines of members of the mustelid subfamily Mustelinae and examined whether size ratios tend towards equality. We then examined whether insular guilds are characterized by larger size ratios and a higher degree of sexual size dimorphism than mainland guilds, and whether this reflects evolution towards the size of missing guild members.

Results We found equal ratios between skull lengths but not canine diameters in all mainland guilds. Few insular guilds showed equal ratios for either trait. There was scant evidence for character release: insular mustelines do not evolve towards the size of a missing guild member, nor is sexual size dimorphism greater on islands. There was no evidence for a lower limit on the size similarity of co‐existing mustelids.

Main conclusions We propose that different guild compositions in different localities produce different evolutionary trajectories. Similar sizes on islands and mainlands can be explained by similar prey sizes in both settings. Morphological evidence suggests that competition is probably not a ubiquitous force in the assembly and evolution of musteline guilds.
Ecogeographical rules: elements of a synthesis
Authors: Gaston Kevin J. , Chown Steven L. , Evans Karl L.
Published: August 2007

The development of a more synthetic approach to understanding spatial patterns in biogeography, particularly of the way in which these patterns interact, constitutes a major challenge for the field. Here we propose some key elements of such a synthesis for what can broadly be termed ‘ecogeographical rules’, that is spatial patterns in biological traits. These include understanding: (1) the different kinds of patterns (intraspecific, interspecific and assemblage), and the distinctions between them; (2) the unifying role that geographical ranges play in linking the patterns together; (3) that this unification can be obscured by the methodological assumptions made in documenting some patterns (e.g. assuming that intraspecific variation does not significantly influence interspecific and assemblage patterns in traits); (4) the implications of other methodological issues for the nature of observed patterns (e.g. how ranges are located on positional or environmental axes for interspecific patterns); (5) the need for further development of models linking different types of traits; (6) the nature of the generality of documented patterns at all levels, and particularly the difference between the frequency with which patterns are documented in the literature and the variety of extant species; and (7) the constraints that the form of intraspecific patterns place on interspecific and assemblage patterns, and that interspecific patterns place on assemblage patterns.
Siblings of individuals with autism or Down syndrome: effects on adult lives
Authors: Orsmond G. I. , Seltzer M. M.
Published: August 2007

Background  In this study, we examine instrumental and affective involvement in the sibling relationship for adults who have a brother or sister with an autism spectrum disorder (ASD) or Down syndrome (DS). We ask three research questions: (1) How do adult siblings of individuals with ASD differ from siblings of individuals with DS in their assessment of the quality of the sibling relationship and their experience of growing up with a brother or sister with a disability? (2) Are there gender effects on the sibling relationship and sibling experience in these two groups? (3) Which factors are predictive of variation in the sibling relationship for siblings of adults with ASD or DS?

Methods  Data from 154 siblings who participated in two linked longitudinal studies were used. Seventy‐seven siblings with a brother or sister with ASD were matched by age and gender to 77 siblings with a brother or sister with DS. The siblings in each group were between 21 and 56 years of age and over half were sisters. Siblings completed questionnaires on instrumental and affective involvement with their brother or sister with ASD or DS, the impact of growing up with a brother or sister with a disability on their lives, and their coping skills and feelings of pessimism.

Results  Compared with the siblings of adults with DS, siblings of adults with ASD had less contact with their brother or sister, reported lower levels of positive affect in the relationship, felt more pessimistic about their brother or sister's future, and were more likely to report that their relationships with their parents had been affected. For siblings of adults with ASD, a closer sibling relationship was observed when the sibling had lower educational levels, lived closer to the brother or sister with ASD, used more problem‐focused coping strategies, and when his or her brother or sister with ASD had higher levels of functional independence. In contrast, for siblings of adults with DS, a closer sibling relationship was observed when the sibling did not have children, had lower levels of education, lived closer to the brother or sister with DS, when he or she used more problem‐focused coping, was less pessimistic about the brother or sister's future, and when his or her life had been impacted to a greater extent by growing up with a brother or sister with DS.

Conclusions  We discuss the implications of these findings for future caregiving roles for siblings. Siblings of individuals with ASD may face difficulty when their parents are no longer able to be the primary caregivers for their brother or sister with ASD, as they tend to have less emotional closeness and are more pessimistic about their brother or sister's future than siblings of individuals with DS. Moreover, in both groups, a closer sibling relationship was observed when the sibling used more problem‐focused coping strategies, which may have implications for intervention.
Infant attentional behaviours as prognostic indicators in Cornelia‐de‐Lange syndrome
Authors: Sarimski K.
Published: August 2007

Background  Cornelia‐de‐Lange syndrome is a rare congenital syndrome with poor social relatedness as one of several characteristics of its behavioural phenotype.

Methods  Video observations were collected from seven children in their first year of life and again with age 2–4 years. Data were analysed for distribution of object‐related and social attention and for relationships between early and later observations.

Results  The findings suggest some inter‐individual stability for social relatedness.

Conclusions  Low frequency of eye‐contact in early interaction may serve as a risk factor. Intensive early interaction is recommended in early stimulation programmes.
Interviewing alleged victims with intellectual disabilities
Authors: Cederborg A.‐C. , Lamb M.
Published: August 2007

Background  When interviewing alleged victims of crime, it is important to obtain reports that are as accurate and complete as possible. This can be especially difficult when the alleged victims have intellectual disabilities (ID). This study explored how alleged victims with ID are interviewed by police officers in Sweden and how this may affect their ability to report information as accurately as possible.

Methods  Twelve interviews with 11 alleged victims were selected from a larger sample. The complainants were interviewed when their chronological ages ranged from 6.1 to 22 years. A quantitative analysis examined the type of questions asked and the numbers of words and details they elicited in response.

Results  Instead of open‐ended questions, the interviewers relied heavily on focused questions, which are more likely to elicit inaccurate information. When given the opportunity, the witnesses were able to answer directive questions informatively.

Conclusions  Interviewers need special skills in order to interview alleged victims who have ID. In addition to using more open‐ended questions, interviewers should speak in shorter sentences.
The behavioural phenotype of Cornelia de Lange Syndrome: a study of 56 individuals
Authors: Basile E. , Villa L. , Selicorni A. , Molteni M.
Published: August 2007

Background  Few studies have investigated functional and behavioural variables of Cornelia de Lange Syndrome (CdLS) in a large sample of individuals. The aim of this study is to provide greater insight into the clinical, behavioural and cognitive characteristics that are associated with CdLS.

Methods  In total, 56 individuals with CdLS participated in the study. During hospitalization, their mothers received a number of questionnaires to complete. The behavioural phenotype was investigated using the following scales: Developmental Behaviour Scale Primary Carer Version; Autism Behaviour Checklist; Childhood Autism Rating Scale.

Results  Our participants demonstrated some behavioural characteristics that are frequently associated with CdLS (hyperactivity, attention disorder, anxiety, compulsive disorders, self‐injurious behaviour and autistic‐like features). Our findings demonstrate the variability of behavioural characteristics in CdLS in addition to highlighting the contribution of some variables to both the CdLS behavioural profile and the developmental trajectory of the behavioural pattern.

Conclusions  The behavioural characteristics identified in our sample were correlated with some clinical and functional aspects (chronological age, cognitive level and clinical phenotype). The variability of the behavioural profile in CdLS reflected the wide variability in cognitive and adaptive functioning across individuals and led us to conclude that there may be multiple behavioural phenotypes associated with the syndrome. Further comparative studies between CdLS and individuals with intellectual disability or other genetic syndromes may help to provide further understanding of the behavioural phenotype of CdLS.
Feasibility and outcomes of multiplex ligation‐dependent probe amplification on buccal smears as a screening method for microdeletions and duplications among 300 adults with an intellectual disability of unknown aetiology
Authors: Peppink D. , Douma‐Kloppenburg D. D. , De Rooij‐Askes E. S. P. , Van Zoest I. M. , Evenhuis H. M. , Gille J. J. P. , Van Hagen J. M.
Published: August 2007

Background  Determining the aetiology of intellectual disability (ID) enables anticipation of specific comorbidity and can thus be beneficial. Blood sampling, however, is considered stressful for people with ID. Our aim was to evaluate the feasibility of a non‐invasive screening technique of nine microdeletions/duplications among adults with ID of unknown aetiology.

Methods  In a random sample of 300 adult clients of Dutch ID services without an aetiological diagnosis, DNA was collected on site using oral swabs. Multiplex Ligation‐dependent Probe Amplification was applied to screen for nine microdeletions/duplications related to ID syndromes (Williams 22q11‐deletion, 1p‐deletion, Miller–Dieker, Smith–Magenis, Prader–Willi, Alagille, Saethre–Chotzen and Sotos syndrome).

Results  Feasibility: prior to the consent procedure, for 2.1% (10/471 eligible participants), the method was considered undesirable. In 0.7% (2/300 participants) oral swabs failed because of resistant behaviour, while in 16.1% (48/298 swabs) analysis was unsuccessful because of insufficient amounts of DNA. A repeated attempt yielded an equal success rate.

Outcome  Microdeletions were diagnosed in four participants: 22q11 deletion (n = 2), 5q35 deletion (Sotos syndrome) (n = 1) and 1p deletion (n = 1). One participant had a duplication of the Prader–Willi Region (15q11‐13) owing to mosaicism of a supernumerary marker chromosome (15).

Conclusions  Oral swabs are a feasible method for DNA sampling in adults with IDs. A diagnosis could be made in five out of 275 people with ID of unknown aetiology. After screening, in the total population sample (n = 620), the prevalence of syndromes associated with the microdeletions/duplications studied was at least 2.3% (95% confidence interval 1.1–3.4%).
Foundations of phonological awareness in pre‐school children with cerebral palsy: the impact of intellectual disability
Authors: Peeters M. , Verhoeven L. , Van Balkom H. , De Moor J.
Published: August 2007

Background  Children with cerebral palsy (CP) and accompanying disabilities are prone to reading difficulties. The aim of the present study was to examine the foundations of phonological awareness in pre‐school children with CP in comparison with a normally developing control group. Rhyme perception was regarded as an early indicator of phonological awareness, whereas non‐verbal reasoning, speech ability, auditory perception, auditory short‐term memory and vocabulary were regarded as foundation measures.

Methods  A number of tasks were administrated to examine group differences in rhyme perception and its foundation measures. Correlations between the tasks were analysed for both groups followed by multiple regression analyses wherein rhyme perception was predicted by its foundation measures.

Results  Children with CP scored below their normally developing peers on emergent phonological awareness and its foundation measures. Regarding the prediction of phonological awareness, non‐verbal reasoning followed by pseudoword articulation, were found to predict phonological awareness, i.e. rhyme perception, in the group of children with CP. In the control group, auditory perception was a significant predictor of emergent phonological awareness. The CP group was further split up into two groups according to the children's non‐verbal reasoning skills, i.e. general IQ. The below‐average IQ group scored below the average IQ group on phonological awareness and on most foundation measures. In addition, the average IQ group of the children with CP scored lower than the control group.

Conclusion  The results of this study indicate that general intelligence and speech ability (i.e. pseudoword articulation) can be seen as important facilitators of emergent phonological awareness in children with CP. These findings support the role of intelligence in the emergence of phonological awareness in children with CP. Children with CP with intellectual disabilities seem to have a disadvantage in acquiring phonological awareness, especially when their speech abilities are also impaired. However, general intelligence is not enough to predict phonological awareness as other foundation measures are also important for phonological awareness independent of general intelligence.
Population structure of a large blue butterfly and its specialist parasitoid in a fragmented landscape
Authors: ANTON CHRISTIAN , ZEISSET INGA , MUSCHE MARTIN , DURKA WALTER , BOOMSMA JACOBUS J. , SETTELE JOSEF
Published: August 2007

Habitat fragmentation may interrupt trophic interactions if herbivores and their specific parasitoids respond differently to decreasing connectivity of populations. Theoretical models predict that species at higher trophic levels are more negatively affected by isolation than lower trophic level species. By combining ecological data with genetic information from microsatellite markers we tested this hypothesis on the butterflyMaculinea nausithousand its specialist hymenopteran parasitoidNeotypus melanocephalus. We assessed the susceptibility of both species to habitat fragmentation by measuring population density, rate of parasitism, overall genetic differentiation (θST) and allelic richness in a large metapopulation. We also simulated the dynamics of genetic differentiation among local populations to asses the relative effects of migration rate, population size, and haplodiploid (parasitoid) and diploid (host) inheritance on metapopulation persistence. We show that parasitism byN. melanocephalusis less frequent at larger distances to the nearest neighbouring population ofM. nausithoushosts, but that host density itself is not affected by isolation. Allelic richness was independent of isolation, but the mean genetic differentiation among local parasitoid populations increased with the distance between these populations. Overall, genetic differentiation in the parasitoid wasp was much greater than in the butterfly host and our simulations indicate that this difference is due to a combination of haplodiploidy and small local population sizes. Our results thus support the hypothesis thatNeotypusparasitoid wasps are more sensitive to habitat fragmentation than theirMaculineabutterfly hosts.
Multilocus heterozygosity and inbreeding depression in an insular house sparrow metapopulation
Authors: JENSEN HENRIK , BREMSET ERLEND MYRE , RINGSBY THOR HARALD , SÆTHER BERNT‐ERIK
Published: August 2007

Inbreeding causes reduction of genetic variability that may have severe fitness consequences. In spite of its potentially huge impact on viability and evolutionary processes especially in small populations, quantitative demonstrations of genetic and demographic effects of inbreeding in natural populations are few. Here, we examine the relationship between individual inbreeding coefficients (F) and individual standardized multilocus heterozygosity (H) in an insular metapopulation of house sparrows (Passer domesticus) in northern Norway in order to evaluate whetherHis a good predictor forF. We then relate variation in fitness (i.e. the probability of surviving from fledging to recruitment) toFandH, which enables us to examine whether inbreeding depression is associated with a reduction in genetic variability. The average level of inbreeding in the house sparrow metapopulation was high, and there was large inter‐individual variation inF. As expected, standardized multilocus heterozygosity decreased with the level of inbreeding. The probability of recruitment was significantly negatively related toF, and, accordingly, increased withH. However,Hexplained no significant additional variation in recruitment rate than was explained byF. This suggests thatHis a good predictor forFin this metapopulation, and that an increase inFis likely to be associated with a general increase in the level of homozygosity on loci across the genome, which has severe fitness consequences.
Cryptic speciation and patterns of phenotypic variation of a highly variable acanthocephalan parasite
Authors: STEINAUER M. L. , NICKOL B. B. , ORTÍ G.
Published: August 2007

An investigation of a parasite species that is broadly host‐ and habitat‐specific and exhibits alternative transmission strategies was undertaken to examine intraspecific variability and if it can be attributed to cryptic speciation or environmentally induced plasticity. Specimens of an acanthocephalan parasite, Leptorhynchoides thecatus, collected throughout North America were analysed phylogenetically using sequences of the cytochrome oxidase I gene and the internal transcribed spacer region. Variation in host use, habitat use, and transmission were examined in a phylogenetic context to determine if they were more likely phylogenetically based or due to environmental influences. Results indicated that most of the variation detected can be explained by the presence of cryptic species. The majority of these species have narrow host and microhabitat specificities although one species, which also may comprise a complex of species, exhibits broad host and habitat specificity. Alternate transmission pathways only occurred in two of the cryptic species and correlate with host use patterns. Taxa that mature in piscivorous piscine hosts use a paratenic fish host to bridge the trophic gap between their amphipod intermediate host and piscivorous definitive host. One potential example of environmentally induced variation was identified in three populations of these parasites, which differ on their abilities to infect different host species.
Fruit load and elevation affect ethylene biosynthesis and action in apple fruit (Malus domestica L. Borkh) during development, maturation and ripening
Authors: CIN VALERIANO DAL , DANESIN MARCELLO , BOTTON ALESSANDRO , BOSCHETTI ANDREA , DORIGONI ALBERTO , RAMINA ANGELO
Published: August 2007

The influence of internal and external factors such as tree fruit load and elevation on ethylene biosynthesis and action was assessed during apple fruit development and ripening. Ethylene biosynthesis, as well as transcript accumulation of the hormone biosynthetic enzymes (MdACS1 and MdACO1), receptors (MdETR1 and MdERS1) and an element of the transduction pathway (MdCTR1), were evaluated in apples borne by trees with high (HL) and low (LL) fruit load. Orchards were located in two localities differing in elevation and season day degree sum. These parameters significantly affected the date of bloom and commercial harvest, and the length of the fruit developmental cycle. Trees from the low elevation (LE) bloomed and the fruit ripened earlier than those from the high elevation (HE), displaying also a shortened fruit developmental cycle. Dynamics of ethylene evolution was apparently not affected by elevation. The onset of ethylene evolution started 130 days after bloom (DAB) at both elevations. During early ripening, fruits from LL trees produced significantly more ethylene than those from HL trees. Expression analysis of MdACS1, MdACO1 and MdERS1 indicated that the transcript accumulation well correlated with ethylene evolution. MdCTR1 was expressed at constant level throughout fruit growth and development up to 130 DAB, thereafter, the transcript accumulation decreased up to commercial harvest, concurrently with the onset of ethylene evolution.
CARDIOVASCULAR AND SURVIVAL PARADOXES IN DIALYSIS PATIENTS: Role of Leptin in Reverse Epidemiology in Chronic Kidney Disease
Authors: Scholze Alexandra , Tepel Martin
Published: August 2007

Leptin is mainly produced by adipocytes and metabolized in the kidney. Leptin is taken up into the central nervous system by a saturable transport system, and controls appetite in rodents and in healthy subjects. Leptin acts on peripheral tissue and increases the inflammatory response by stimulating the production of tumor necrosis factor alpha, interleukin‐6 and interleukin‐12. In healthy humans, serum leptin concentration is related to the size of adipose tissue mass in the body. The majority of obese subjects have inappropriately high levels of circulating plasma leptin concentrations, indicating leptin resistance. In healthy subjects increased leptin concentration constitutes a biomarker for increased cardiovascular risk. On the other hand, a recent prospective long‐term study in patients with chronic kidney disease stage 5 on hemodialysis therapy showed that reduced serum leptin concentration is an independent risk factor for mortality in these patients.
CARDIOVASCULAR AND SURVIVAL PARADOXES IN DIALYSIS PATIENTS: Kinetic Studies of Atherogenic Lipoproteins in Hemodialysis Patients: Do They Tell Us More about Their Pathology?
Authors: Kronenberg Florian , Ikewaki Katsunori , Schaefer Juergen R. , König Paul , Dieplinger Hans
Published: August 2007

Patients with chronic kidney disease have one of the highest risks for atherosclerotic complications. Several large epidemiological studies described an opposite association of total and low density lipoprotein (LDL) cholesterol with cardiovascular complications and total mortality compared to the general population, a circumstance often called “reverse epidemiology.” Many factors might contribute to this reversal such as interaction with malnutrition/inflammation, pronounced fluctuations of atherogenic lipoproteins during the course of renal disease, heterogeneity of lipoprotein particles with preponderance of remnant particles, and chemical modification of lipoproteins caused by the uremic environment. A vicious cycle has been suggested in uremia in which the decreased catabolism of atherogenic lipoproteins such as LDL, IDL and Lp(a) leads to their increased plasma residence time and further modification of these lipoproteins by oxidation, carbamylation, and glycation. Using stable isotope techniques, it has been shown recently that the plasma residence time of these particles is more than twice as long in hemodialysis patients as in nonuremic subjects. This reduced catabolism, however, is masked by the decreased production of LDL, resulting in near‐normal plasma levels of LDL. The production rate of Lp(a) in hemodialysis patients is similar to that in controls which together with the doubled residence time results in elevated Lp(a) levels. An increased clearance of these altered lipoproteins via the scavenger receptors of macrophages leads to the transformation of macrophages into foam cells in the vascular wall and might contribute to the pronounced risk for cardiovascular complications of these patients. These observations suggest that the real danger of these particles is not reflected by the measured concentrations but by their metabolic qualities.
CARDIOVASCULAR AND SURVIVAL PARADOXES IN DIALYSIS PATIENTS: The Association between Blood Pressure and Mortality in ESRD—Not Different from the General Population?
Authors: Lacson Eduardo , Lazarus J. Michael
Published: August 2007

Hypertension (HTN) is a traditional cardiovascular risk factor and is prevalent in end‐stage renal disease (ESRD). There are no adequately powered prospective studies that explore the natural history and outcomes of HTN and blood pressure management in ESRD. Observational studies have not uniformly showed a relationship between HTN and mortality risk in this population. Furthermore, many studies paradoxically show an increased risk of death associated with low and “normal” blood pressure (BP), sometimes referred to as “reverse epidemiology.” We review findings from observational studies specifically performed in ESRD and provide an alternative interpretation—that patients with kidney disease on dialysis therapy are indeed different from the general population. At minimum, these differences may be based on the prevalence of cardiovascular morbidity, specifically the excessive prevalence of congestive heart failure. However, there are other reasons for ESRD patients, especially those on hemodialysis, to exhibit differential effects with regard to blood pressure and outcomes. We explore the implications of available observational evidence and recommend studies that elucidate the differences between ESRD and the general population. Because of the higher mortality risk associated with low or “normal” BP, diagnostic and therapeutic options and strategies for ESRD patients whose BP falls within “goal” should be addressed in future iterations of clinical practice guidelines. These strategies may include assessment of cardiac function and careful attention to achieving optimal fluid balance.
CARDIOVASCULAR AND SURVIVAL PARADOXES IN DIALYSIS PATIENTS: Misleading Associations between Cholesterol and Vascular Outcomes in Dialysis Patients: The Need for Randomized Trials
Authors: Baigent Colin , Landray Martin J. , Wheeler David C.
Published: August 2007

Higher cholesterol is strongly associated with an increased risk of coronary heart disease (CHD) in nonrenal populations, so the lack of a clear positive association between total cholesterol and mortality among dialysis patients is unexpected. This review of prospective studies of the association between total cholesterol and mortality among dialysis patients suggests that there is a negative association at below average cholesterol levels and a flat or weakly positive association at higher levels. In nonrenal populations total cholesterol is not positively associated with vascular causes of death other than CHD, so the lack of a strongly positive association at above average cholesterol concentrations in dialysis patients may be explained by the high proportion of deaths due to non‐CHD vascular causes. The observation of a negative association between total cholesterol and mortality at below average cholesterol concentrations in some studies is consistent with confounding by both vascular and nonvascular morbidity (i.e., reverse causality). We argue that evaluating the importance of cholesterol for vascular disease risk in dialysis patients can only be achieved through the eradication of confounding by randomization, and that ongoing trials of cholesterol‐lowering therapy will provide a definitive answer to this question.
Clinical predictors of alloimmunization after red blood cell transfusion
Authors: Bauer Martijn P. , Wiersum‐Osselton Jo , Schipperus Martin , Vandenbroucke Jan P. , Briët Ernest
Published: August 2007

BACKGROUND: Development of new red blood cell (RBC) alloantibodies (alloimmunization) is one of the most frequent adverse reactions after an RBC transfusion. Few studies have investigated clinical risk factors for alloimmunization.

STUDY DESIGN AND METHODS: In this case‐control study, the characteristics of all patients in whom alloimmunization occurred for the first time after an RBC transfusion in two hospitals between January 1, 2003, and May 5, 2005, were examined and compared to a randomly selected control group who received RBC transfusions in the same hospitals during the same period without alloimmunization. Odds ratios (ORs) for the association between these characteristics and alloimmunization were calculated and analyzed with a logistic regression model.

RESULTS: Eighty‐seven cases were found, and 101 controls were selected. Female sex (OR, 1.89; 95% confidence interval [CI], 1.05‐3.38), diabetes mellitus (OR, 2.15; 95% CI, 0.91‐5.05), solid malignancy (OR, 2.07; 95% CI, 1.00‐4.30), and previous allogeneic hematopoietic peripheral blood progenitor cell (PBPC) transplantation (OR, 2.24; 95% CI, 0.64‐7.81) were associated most strongly with alloimmunization, whereas lymphoproliferative disorders (OR, 0.33; 95% CI, 0.13‐0.81) and symptomatic atherosclerosis (OR, 0.52; 95% CI, 0.25‐1.08) were associated with the absence of alloimmunization. All of these associations except for female sex became stronger after adjustment for possible confounders.

CONCLUSION: Female sex, diabetes mellitus, solid malignancy, and previous allogeneic PBPC transplantation seem to be risk factors for alloimmunization, whereas lymphoproliferative disorders and symptomatic atherosclerosis seem to protect against it. Further studies are needed to confirm these associations and investigate underlying mechanisms.
Blood bank management of sickle cell patients at comprehensive sickle cell centers
Authors: Afenyi‐Annan Araba , Willis Monte S. , Konrad Thomas R. , Lottenberg Richard
Published: August 2007

BACKGROUND: Transfusion therapy has been integral to decreasing morbidity and mortality in sickle cell disease (SCD). Several studies however, have demonstrated variation in the blood bank (BB) practices for these patients. The purpose of this study was to examine BB practices for SCD patients at NIH Comprehensive Sickle Cell Centers (CSCCs) and to determine whether consensus in BB management exists.

STUDY DESIGN AND METHODS: A cross‐sectional survey of BB medical directors and laboratory supervisors at CSCCs was conducted between October 2004 and March 2005. The survey assessed respondent, hospital, and BB characteristics; pretransfusion procedures; blood product selection; and agreement with statements about consensus in management. Physician respondents were also asked to select their preferred management strategy in four hypothetical transfusion‐related cases.

RESULTS: Responses were received from 36 of 49 (73.5%) institutions. Pretransfusion procedures and blood product selection were nearly uniform among CSCCs. Of the respondents, 69 percent disagreed with the statement that clear consensus exists on the use of phenotypically matched red blood cells for SCD patients; 55 percent disagreed that clear consensus exists on the use of chronic transfusion programs for SCD patients. Although there was consensus on the use of transfusion therapy for life‐ or organ‐threatening situations, optimal management of preoperative transfusion therapy and severe delayed transfusion reactions appears controversial.

CONCLUSION: This study provides the first overview of BB management of patients with SCD at CSCCs and identifies areas where there is perceived and actual lack of consensus. These results suggest that opportunities remain to standardize transfusion practices for SCD patients across all hospital settings.
Hematology patterns after hemoglobin‐based oxygen carrier resuscitation from severe controlled hemorrhage with prolonged delayed definitive care
Authors: Arnaud Francoise , Fasipe Daniel , Philbin Nora , Rice Jennifer , Flournoy W. Shannon , Ahlers Stephen , McCarron Richard , Freilich Daniel
Published: August 2007

BACKGROUND: The hemoglobin‐based oxygen carrier (HBOC‐201) resuscitation fluid improves outcome in hemorrhagic shock swine models with minimal coagulopathy. Herein, coagulation parameters were evaluated after resuscitation with HBOC‐201 after severe bleeding and prolonged delay to definitive care.

STUDY DESIGN AND METHODS: After 55 percent estimated blood volume–controlled hemorrhage by catheter withdrawal, swine (n = 48) were resuscitated with HBOC‐201 or Hextend (HEX) infused in four doses over 4 hours or not resuscitated (NON). Animals were randomly assigned in two cohorts of 4‐ or 24‐hour simulated delay to hospital arrival (access to blood and saline infusions up to 72 hr). In vitro hematologic monitoring was assessed with complete blood count, hemostasis (thromboelastography [TEG], in vitro bleeding time [PFA]), and coagulation (prothrombin time [PT], thrombin‐antithrombin, fibrinogen) indices.

RESULTS: Within groups, survival was unaffected by extending delay from 4 to 24 hours. Combined survival was similar for HBOC‐201 and HEX but lower for NON animals (93.5, 81.5, and 25 percent, respectively; p < 0.01). Blood transfusion requirements were lower with HBOC‐201 than HEX. Elevated TEG and PFA parameters in resuscitated animals reflected fluid and blood transfusion regimens. TEG reaction time and PFA were transiently higher with HBOC‐201 than with HEX during the early hospital phase. PT was increased in HEX animals.

CONCLUSION: In this severe model, survival was equivalent with HBOC‐201 and HEX resuscitation. HBOC‐201 or HEX allowed delayed hospital arrival to 24 hours without worsening coagulation parameters, but dilutional mild coagulopathy in the hospital phase persisted with HBOC‐201 due to blood transfusion avoidance. Low hematocrit suggests that blood administration after HBOC‐201 resuscitation could be beneficial to replete blood cellular mass.
Rapid and effective CD3 T‐cell depletion with a magnetic cell sorting program to produce peripheral blood progenitor cell products for haploidentical transplantation in children and adults
Authors: Dykes Josefina H. , Toporski Jacek , Juliusson Gunnar , Békássy Albert N. , Lenhoff Stig , Lindmark Anders , Scheding Stefan
Published: August 2007

BACKGROUND: Effective T‐cell depletion is a prerequisite for haploidentical peripheral blood progenitor cell (PBPC) transplantation. This study was performed to investigate the performance of magnetic cell sorting–based direct large‐scale T‐cell depletion, which is an attractive alternative to standard PBPC enrichment procedures.

STUDY DESIGN AND METHODS: PBPCs were harvested from 11 human leukocyte antigen (HLA)‐haploidentical donors. T cells labeled with anti‐CD3–coated beads were depleted with a commercially available magnetic separation unit (CliniMACS, Miltenyi Biotec) with either the Depletion 2.1 (D2.1, n = 11) or the novel Depletion 3.1 (D3.1, n = 12) program. If indicated, additional CD34+ selections were performed (n = 6). Eleven patients received T‐cell‐depleted grafts after reduced‐intensity conditioning.

RESULTS: The median log T‐cell depletion was better with the D2.1 compared to the D3.1 (log 3.6 vs. log 2.3, p < 0.05) and was further improved by introducing an immunoglobulin G (IgG)‐blocking step (log 4.5 and log 3.4, respectively). The D3.1 was superior to the D2.1 (p < 0.05) in median recovery of CD34+ cells (90% vs. 78%) and in median recovery of CD3– cells (87% vs. 76%). The median processing times per 1010 total cells were 0.90 hours (D2.1) and 0.35 hours (D3.1). The transplanted grafts (directly T‐cell–depleted products with or without positively selected CD34+ cells) contained a median of 10.5 × 106 per kg CD34+, 0.93 × 105 per kg CD3+, and 11.6 × 106 per kg CD56+. Rapid engraftment was achieved in 10 patients. The incidences of acute graft‐versus‐host disease were less than 10 percent (Grade I/II) and 0 percent (Grade III/IV).

CONCLUSION: The novel D3.1 program with IgG blocking enables highly effective, time‐saving large‐scale T‐cell depletion. Combining direct depletion techniques with standard CD34+ selection enables the composition of grafts optimized to the specific requirements of the patients.
Influence of nutrition on disease development caused by fungal pathogens: implications for plant disease control
Authors: Walters D.R. , Bingham I.J.
Published: August 2007

A great deal of information is available in the literature on the effects of nutrition on disease development in plants and crops. However, much of this information is contradictory and although it is widely recognised that nutrition can influence disease in crops, limited progress has been made in the manipulation of crop nutrition to enhance disease control. Achieving this aim requires a sound understanding of the effects of fertilisation on nutrient levels and availability in crop tissues, and in turn, how the nutrient status of such tissues influences pathogen infection, colonisation and sporulation. Some of these details are known for a number of crop plants under controlled conditions, but very little of this type of information is available for crops under field conditions. This review focuses on nitrogen, sulphur, phosphorus, potassium and silicon, examines the availability of these nutrients in plant tissues to support pathogen growth and development, and reviews the effects of the different nutrients on disease development. The review also examines the potential for manipulating crop nutrition to enhance disease control in conventional and organic cropping systems.
Insect symbionts and applications: The paradigm of cytoplasmic incompatibility‐inducing Wolbachia
Authors: Panagiotis IOANNIDIS , BOURTZIS Kostas
Published: August 2007

Wolbachia is a group of Gram‐negative, obligatory intracellular and maternally transmitted alpha‐Proteobacteria. They have been reported to establish symbiotic relationships with a great variety of species of the most diverse animal class, the insects, as well as with several other arthropods and with filarial nematodes. The reproductive alterations Wolbachia causes in its hosts account for its widespread distribution. These alterations include parthenogenesis, feminization, male killing, and cytoplasmic incompatibility (CI). CI is the most frequent and best studied effect Wolbachia has on its hosts. CI is a form of male sterility, ultimately resulting in embryo lethality in diplodiploid host species. As a consequence of CI, Wolbachia infections spread and lead to the replacement of uninfected populations. CI was used nearly four decades ago to control important disease vectors with very encouraging results, and a number of more recent studies have confirmed the effectiveness of CI as a pest population suppression tool as well as a driving mechanism. Furthermore, recent advancements in the field encourage the development of Wolbachia‐based methods for the biological control of insect pests and disease vectors of agricultural, environmental and medical importance.
Cost-effectiveness analysis of a proposed public health legislative/educational strategy to reduce tap water scald injuries in children
Authors: Han Ra K , Ungar Wendy J , Macarthur Colin
Published: August 2007

Objective:To determine the cost effectiveness of a public health legislative/educational strategy to reduce tap water scalds in children less than 10 years of age.

Design:Cost-effectiveness analysis conducted from the government perspective over a 10-year time horizon.

Population:Children under 10 years of age in Ontario, Canada

Interventions:Legislation to set thermostat settings on new domestic water heaters to lower temperatures (maximum 49°C) plus annual educational notices to utility customers versus status quo.

Main outcome measures:The burden of tap water scalds, healthcare resource utilization, the cost and effectiveness of the proposed intervention, and the probabilities assigned to health outcomes were modeled in a decision analysis based on population-based data, patient charts, and the published medical literature. All costs and health outcomes beyond 1 year were discounted at 3%.

Results:An estimated 182 children under 10 require medical care for tap water scald injuries annually in Ontario (13.98 per 100 000). Of these, 65 require emergency department (ED) care only (median cost $C149 per injury), 103 require ED care with clinic follow-up ($C577 per injury), 14 require hospital admission ($C5203 per injury), and two require surgical skin grafting ($C28 526 per injury). The estimated cost of the intervention was $C51 000 annually, with a projected 56% reduction in tap water scald injuries. Over 10 years, the intervention group would show total costs of $C1.17 million and 704 scalds, compared with $C1.65 million and 1599 scalds in the status quo group. Therefore, the intervention would be cost saving, with an incremental ratio of $C531 saved per scald averted. Sensitivity analyses showed that the intervention would remain cost saving through a wide range of variable estimates.

Conclusions:Legislation to lower thermostat settings on domestic water heaters plus annual educational notices to utility customers would generate cost savings while reducing the morbidity from tap water scalds in children.
Hospitalized head injuries among older people in Australia, 1998/1999 to 2004/2005
Authors: Jamieson Lisa M , Roberts-Thomson Kaye F
Published: August 2007

Objective:To explore rates of hospitalized head injury among older Australians by a range of risk indicators.

Design:Head injury data for 60+-year-olds were obtained from the Australian Institute of Health and Welfare Hospital Morbidity Database from 1998/1999 to 2004/2005. Poisson regression modeling was used to examine head injury rates in relation to age, sex, Indigenous status, location, and injury type.

Results:Rates of hospitalized head injury among the older population increased 1.4-fold between 1998/1999 (582.8 per 100 000) and 2004/2005 (844.3 per 100 000) (p<0.001). Those aged 85+ years had 10.8 times the rate of their 60–64-year-old counterparts (95% CI 10.6 to 11.0) after adjustment for other covariates. Men had 1.1 times the rate of women (95% CI 1.1 to 1.2), and those living in rural/remote areas had 3.1 times the rate of their metropolitan-dwelling counterparts (95% CI 3.0 to 3.1). Those identifying themselves as Indigenous had 1.7 times the rate of non-Indigenous persons (95% CI 1.6 to 1.8). The most prevalent injuries were open wounds of the head (38.0%), followed by superficial injuries (24.7%) and intracranial trauma (18.3%). Falls accounted for 81.4% of all head injury admissions.

Conclusions:The oldest old were disproportionately represented among those sustaining hospitalized head injuries, along with men, those living in rural/remote areas, and Indigenous persons. Given the increasing proportion of older people in Western societies and the costs of treating hospitalized head injuries, the ability to reduce risk of such trauma in this age group is of critical public health importance.