bluuebunny/crossref_metadata_2025_split huggingface dataset:
Survival bias in observational studies of the impact of routine immunizations on childhood survival
Authors: Jensen Henrik , Benn Christine Stabell , Lisse Ida Maria , Rodrigues Amabelia , Andersen Per Kragh , Aaby Peter 
Published: November 2006

SummaryObjectives  In situations with vaccination coverage high enough to control pertussis, observational studies have reported divergent effects of diphtheria–tetanus–pertussis (DTP) vaccination on childhood survival. We examined whether this could be because of methodological differences.Methods  Some studies of the impact of DTP updated information on vaccination retrospectively (retrospective updating approach) while others kept vaccination status fixed for the time between follow‐up visits (landmark approach). First, we conducted simulations with these approaches to investigate the impact of different mortality levels, vaccination incidence rates, intervals between data collection visits, and the proportion of children whose vaccination card had not been seen after death. Second, we re‐analysed data from Guinea‐Bissau using the retrospective updating approach.Results  In simulations, the retrospective updating approach produced rate ratio (vaccinated/unvaccinated) estimates biased towards zero because of a differential misclassification which created survival bias as risk‐free observation time was allocated to the vaccinated group. The landmark approach produced rate ratio estimates biased towards one. Biases increased with interval between data collection visits and incidence of vaccination, but were unaffected by the underlying mortality level. Survival bias increased with the proportion of dead children whose vaccination status could not be updated. The re‐analysis of data from Guinea‐Bissau changed the estimated impact of DTP from an 84% higher mortality using the landmark approach to a 37% lower mortality using the retrospective updating approach.Conclusions  The apparent contradiction between DTP studies could be because of methodological differences. To assess child survival associated with routine vaccinations, studies minimizing the effect of biases are warranted.
A biological test to quantify pyrethroid in impregnated nets
Authors: Martin T. , Chandre F. , Chabi J. , Guillet P. F. , Akogbeto M. , Hougard J. M. 
Published: November 2006

SummaryFirst instar larvae of Aedes aegypti (L.) (Diptera: Culicidae) are very susceptible to deltamethrin, which kills all larvae at a very low dose (0.1 μg/l). Thus the sensitivity of this insect to detect that pyrethroid is in parts per billion, as obtained with most common chromatographic methods of analysis. Here we describe a biological test (BT) to quantify deltamethrin in long‐lasting insecticidal nets (LLINs) by exposing first instar larvae of Ae. aegypti to serial extracted insecticide solutions from net samples. The deltamethrin concentration in the net was calculated at the doses killing 50% of larva, from the LC50 of deltamethrin (6.5 × 10−5 mg/l) and the dilution factor (DF50) of the extracted net solution. The pyrethroid quantification in LLINs after 0–25 washes with this BT was correlated with those obtained by direct chromatographic analysis (r2 = 0.84). This BT did not require sophisticated equipment and could be extended to other molecules and materials. It appeared accurate, robust, cheap and well adapted to the national malaria programmes as the eggs of Ae. aegypti might be used for some months. This method was adapted to provide an easy to use kit test for the quality control of LLINs in the field.
Is molecular biology the best alternative for diagnosis of malaria to microscopy? A comparison between microscopy, antigen detection and molecular tests in rural Kenya and urban Tanzania
Authors: Mens P. , Spieker N. , Omar S. , Heijnen M. , Schallig H. , Kager P. A. 
Published: November 2006

SummaryObjective  To assess the agreement of different diagnostic methods for the diagnosis and confirmation of the clinical suspicion of Plasmodium infection in children in Tanzania and Kenya.Method  Blood samples were collected by the finger prick method from 338 children. Blood samples were collected from 338 children with the clinical suspicion of uncomplicated malaria in health clinics in Tanzania and Kenya. The presence of Plasmodium parasites was assessed with microscopy, rapid diagnostic tests (RDTs) and the molecular assays, quantitative nucleic acid sequence based amplification (QT‐NASBA) and polymerase chain reaction (PCR). The results were compared and analysed for agreement.Results  There was a high degree of agreement (88.6–100%) between RDTs or molecular tests and microscopy. In rural Kenya, with a high incidence of malaria cases, the correlation coefficient ranged from 0.94 for RDTs to 0.76 for PCR. In urban Tanzania, where there was a low incidence of cases, R for RDTs was 1.0 but only 0.25 for PCR and 0.33 for NASBA.Conclusion  Malaria is overestimated if the diagnosis is based solely on clinical signs. Therefore, laboratory confirmation is essential. Microscopy is a reliable method in rural areas where malaria is prevalent, but RDTs offer a good alternative with the advantage that it is an easy and rapid method. Molecular tests are more sensitive but difficult to implement in rural areas. In areas with lower incidence, molecular tests detect a significantly higher number of Plasmodium infections than RDTs or microscopy. Although implementation of molecular tools can be difficult, the prospect of an easy and cheap detection system makes them promising tools for the near future.
A relative resistance of T cells to dexamethasone in bipolar disorder
Authors: Knijff Esther M , Breunis M Nadine , Van Geest Marielle C , Kupka Ralph W , Ruwhof Cindy , De Wit Harm J , Nolen Willem A , Drexhage Hemmo A 
Published: November 2006

Objective:  A relative resistance of immune cells to steroids has been established in patients with major depression (MD). In this study, we investigated the in vitro responsiveness of T cells to dexamethasone (DEX) of patients with bipolar disorder (BD).Methods:  T cells of outpatients with DSM‐IV BD (n = 54) and of healthy control subjects (HC; n = 29) were isolated, cultured and stimulated with phytohemagglutinin (PHA) for 72 h. The suppressive effect of graded concentrations of DEX (5 × 10−9–10−5 M) on PHA‐induced CD25 (IL‐2R) expression was measured by fluorescence‐activated cell sorting (FACS) analysis. Data were correlated to the T‐cell activation status in the peripheral blood of the same patients and to their diagnosis, current mood state, ultradian cycling pattern and current use of medication, including lithium.Results:  T cells of patients with BD were less sensitive to DEX‐induced suppressive effects as compared with T cells of HC. These data were particularly evident at 10−7 M DEX (mean % suppression ± SEM BD: 18.9% ± 3.5 versus HC: 35.8% ± 4.7, p = 0.001). We found no correlations of this relative in vitro DEX resistance of T cells neither with the previously mentioned clinical characteristics nor with the actual activation status of the T cells in the BD patients.Conclusion:  A relative T‐cell resistance to steroids, as has been observed in MD previously, may be a trait phenomenon of BD, independent of mood state.
Co‐occurrence of bipolar and attention‐deficit hyperactivity disorders in children
Authors: Singh Manpreet K , DelBello Melissa P , Kowatch Robert A , Strakowski Stephen M 
Published: November 2006

Objectives:  Pediatric bipolar disorder (BPD) and attention‐deficit hyperactivity disorder (ADHD) co‐occur more frequently than expected by chance. In this review, we examine 4 potential explanations for the high rate of this common co‐occurrence: (i) BPD symptom expression leads to overdiagnosis of ADHD in BPD youth; (ii) ADHD is a prodromal or early manifestation of pediatric‐onset BPD; (iii) ADHD and associated factors (e.g., psychostimulants) lead to the onset of pediatric BPD; and (iv) ADHD and BPD share an underlying biological etiology (i.e., a common familial or genetic risk or underlying neurophysiology).Methods:  Peer‐reviewed publications of studies of children and adolescents with comorbid BPD and ADHD were reviewed.Results:  There is a bidirectional overlap between BPD and ADHD in youth, with high rates of ADHD present in children with BPD (up to 85%), and elevated rates of BPD in children with ADHD (up to 22%). Phenomenologic, genetic, family, neuroimaging, and treatment studies revealed that BPD and ADHD have both common and distinct characteristics. While there are data to support all 4 explanations postulated in this paper, the literature most strongly suggests that ADHD symptoms represent a prodromal or early manifestation of pediatric‐onset BPD in certain at‐risk individuals. Bipolar disorder with comorbid ADHD may thus represent a developmentally specific phenotype of early‐onset BPD.Conclusions:  The etiology of comorbid BPD and ADHD is likely multifactorial. Additional longitudinal and biological studies are warranted to clarify the relationships between BPD and ADHD since they may have important diagnostic and treatment implications.
Comorbidity of eating disorders with bipolar disorder and treatment implications
Authors: McElroy Susan L , Kotwal Renu , Keck Paul E 
Published: November 2006

Objectives:  To review the scientific evidence examining the comorbidity among eating disorders and bipolar disorder (BD).Methods:  We reviewed all published English‐language studies addressing the comorbidity of anorexia nervosa, bulimia, bulimia nervosa, and binge eating disorder in patients with BD and studies of comorbidity of BD in patients with eating disorders. In addition, we discuss the pharmacologic treatment implications from reviewed studies of agents used in BD and eating disorders.Results:  Community and clinical population studies of the lifetime prevalence rates of eating disorders in patients with BD, and of BD in patients with eating disorders, particularly when subthreshold and spectrum manifestations of these disorders are included, indicate high rates of comorbidity among these illnesses.Conclusions:  Pharmacologic treatment approaches to patients with BD and a co‐occurring eating disorder require examination of the possible adverse effects of the treatment of each syndrome on the other and attempts to manage both syndromes with agents that might be beneficial to both.
Inbreeding avoidance in spiders: evidence for rescue effect in fecundity of female spiders with outbreeding opportunity
Authors: Bilde T. , Maklakov A. A. , Schilling N. 
Published: November 2006

Abstract
Selection by inbreeding depression should favour mating biases that reduce the risk of fertilization by related mates. However, equivocal evidence for inbreeding avoidance questions the strength of inbreeding depression as a selective force in the evolution of mating biases. Lack of inbreeding avoidance can be because of low risk of inbreeding, variation in tolerance to inbreeding or high costs of outbreeding. We examined the relationship between inbreeding depression and inbreeding avoidance adaptations under two levels of inbreeding in the spider Oedothorax apicatus, asking whether preference for unrelated sperm via pre- and/or post-copulatory mechanisms could restore female fitness when inbreeding depression increases. Using inbred isofemale lines we provided female spiders with one or two male spiders of different relatedness in five combinations: one male sib; one male nonsib; two male sibs; two male nonsibs; one male sib and one male nonsib. We assessed the effect of mating treatment on fecundity and hatching success of eggs after one and three generations of inbreeding. Inbreeding depression in F1 was not sufficient to detect inbreeding avoidance. In F3, inbreeding depression caused a major decline in fecundity and hatching rates of eggs. This effect was mitigated by complete recovery in fecundity in the sib–nonsib treatment, whereas no rescue effect was detected in the hatching success of eggs. The rescue effect is best explained by post-mating discrimination against kin via differential allocation of resources. The natural history of O. apicatus suggests that the costs of outbreeding may be low which combined with high costs of inbreeding should select for avoidance mechanisms. Direct benefits of post-mating inbreeding avoidance and possibly low costs of female multiple mating can favour polyandry as an inbreeding avoidance mechanism.
Which patients are more likely to benefit from postoperative shed blood salvage after unilateral total knee replacement? An analysis of 581 consecutive procedures
Authors: Muñoz M. , Kühlmorgen B. , Ariza D. , Haro E. , Marroquí A. , Ramirez G. 
Published: November 2006

Introduction  Requirements for allogeneic blood transfusion (ABT) after total knee replacement (TKR) are still high (30–50%), and salvage of unwashed filtered postoperative shed blood (USB) may represent an alternative to ABT. We evaluated that patients are more likely to benefit of USB reinfusion after TKR.Patients and Methods  Data from 581 consecutive primary TKR, managed with (reinfusion group, n= 382) or without (control group, n= 199) reinfusion of USB, were retrospectively reviewed.Results  Patients from reinfusion group received 119 ± 88 ml of red blood cells from USB, without clinically relevant incidents, and showed a lower ABT rate (30.6% vs. 8·4%, for control and reinfusion groups, respectively; P = 0·001) (transfusion trigger, haemoglobin [Hb] < 9 g/dl). Differences in ABT rate between groups were significant for all preoperative Hb levels, except for Hb ≤ 12 g/dl. A lower transfusion threshold (Hb < 8 g/dl) might have further decreased ABT rate (14·6% vs. 5·2%, respectively; P < 0·001), with differences being significant for preoperative Hb between 12 and 15 g/dl. There were no differences with respect to postoperative infection rate, but patients from reinfusion group had a shorter length of hospital stay (11 ± 4 vs. 13 ± 4 days, respectively; P= 0·001).Conclusions  Return of USB after TKR seems to reduce the need for ABT, especially in patients with preoperative Hb between 12 and 15 g/dl. There is little benefit of USB reinfusion for patients with preoperative Hb > 15 g/dl, whereas patients with preoperative Hb < 12 g/dl would probably benefit from the combination of USB with some other blood‐saving method.
A Comparative Ontogenic Study of Urinary Bladder: Impact of the Epithelial Differentiation in Embryonic and Newborn Rats
Authors: Ersoy Y. , Ercan F. , ÇEtinel Ş. 
Published: November 2006

SummaryThe present study aimed to show the cellular and subcellular distribution of glycogen content during the differentiation of urothelial cells from simple cuboidal to stratified transitional epithelium. Bladder samples were taken from rat embryos on the 15th to 19th days and newborn at 21st day. During the development of the bladder, the formation of fusiform vesicles, asymmetric unit membrane (AUM) and microridges were examined with staining with haematoxylin–eosin and periodic acid Schiff for light microscope and periodic acid–thiocharbohydrazide–silver proteinate for transmission electron microscope. The topographical changes of luminal differentiation were examined with the scanning electron microscope. The urothelium was simple cuboidal from 15th till the 17th days of gestation. Glycogen content was present in the cytoplasm till the 18th day of gestation. At the early stage (16th day) of gestation, the apical surface contains microvilli that points the undifferentiated cells. The density of microvilli decreased and ropy microridges appeared at the 17th day of gestation. The small discoid vesicles lined with AUM developed at the apical cytoplasm of the surface cells at the 17th day of gestation. After this stage, both the density of microridges and large and elongated fusiform vesicles increased. The differentiation of the urothelium begins with the formation of the round and small vesicles, continues with the formation of the AUM and at the final stage there is a decrease in both glycogen content and the appearance of the microridges at the luminal surface of the urothelial cells.
Defining Cytochemical Markers for Different Cell Types in the Equine Retina
Authors: Deeg C. A. , Amann B. , Hauck S. M. , Kaspers B. 
Published: November 2006

SummaryThe major cell types in the mammalian retina are photoreceptors, amacrine, horizontal, bipolar, ganglion and Mueller glial cells. Most of the specific cell types are conserved, but cytochemical markers vary between species. The aim of our study was to characterize cytochemically distinctive markers for different cell types in the equine retina. We were able to define specific markers for equine Mueller glial cells and photoreceptor cells. Furthermore, we describe markers for large ganglion cells, horizontal and amacrine cells and a subpopulation of bipolar cells. Additionally, discrimination between the inner plexiform layer and nerve fibre layer can be achieved by expression of syntaxin and neurofilament 200 respectively.
Variability of Endotoxin Expression in Bt Transgenic Cotton
Authors: Dong H. Z. , Li W. J. 
Published: November 2006

AbstractTransgenic cotton expressing Bt (Bacillus thuringiensis) toxins is currently cultivated on a large commercial scale in many countries, but observations have shown that it behaves variably in toxin efficacy against target insects under field conditions. Understanding of the temporal and spatial variation in efficacy and the resulting mechanisms is essential for cotton protection and production. In this review, we summarize current knowledge on variability in Bt cotton efficacy, in particular on the induced variability by environmental stresses. We also discuss the resulting mechanisms and the countermeasures for the inconsistence in efficacy in Bt cotton. It is indicated that insecticidal protein content in Bt cotton is variable with plant age, plant structure or under certain environmental stresses. Variability in Bt cotton efficacy against target insect pests is mainly attributed to the changes in Bt protein content, but physiological changes associated with the production of secondary compounds in plant tissues may also play an important role. Reduction of Bt protein content in late‐season cotton could be due to the overexpression of Bt gene at earlier stages, which leads to gene regulation at post‐transcription levels and consequently results in gene silencing at a later stage. Methylation of the promotor may be also involved in the declined expression of endotoxin proteins. As a part of total protein, the insecticidal protein in plant tissues changes its level through inhibited synthesis, degradation or translocation to developing plant parts, particularly under environmental stresses, thus being closely correlated to N metabolism. It can be concluded that developing new cotton varieties with more powerful resistance, applying certain plant growth regulators, enhancing intra‐plant defensive capability, and maintenance of general health of the transgenic crop are important in realizing the full transgenic potential in Bt cotton.
Yield–Density Relation of Glyphosate‐Resistant Soya beans and their Responses to Light Enrichment in North‐eastern USA
Authors: Liu X. B. , Herbert S. J. , Zhang Q. Y. , Hashemi A. M. 
Published: November 2006

AbstractOptimum plant population densities are a key means of achieving higher seed yield in soya bean [Glycine max (L.) Merr.]. Limited information is available on yield‐density relation of glyphosate‐resistant soya beans in north‐eastern USA. The objective of this research was to determine the appropriate populations for glyphosate‐resistant soya beans, and if the yield potential of glyphosate‐resistant soya bean produced in light‐enriched conditions was affected by populations. Eight glyphosate‐resistant soya bean cultivars with three populations (300 000, 500 000 and 800 000 plants ha−1) were grown under both ambient and light‐enriched conditions in 2002 and 2003. Yield of all cultivars responded to density linearly. As density increased, grain yield was increased by up to 92 % among cultivars. Light enrichment increased yield for all cultivars across the 2 years, although some cultivars were more sensitive. Harvest index either remained unchanged or declined slightly at higher density in 2002, and there was no difference among treatments in 2003. Both pod number and seed number per plant were significantly decreased with the increase of density across the 2 years, while seeds per pod declined slightly or remained unchanged. Greater seed size was obtained in higher density with varied degree depending on cultivars across the 2 years except for those cultivars with relatively larger seed. The increase in seed size by light enrichment was cultivar and density dependent, and varied between years. 800 000 plants ha−1 could be a suitable practice in producing higher yield in north‐east USA for glyphosate‐resistant soya bean. Maintaining the mass of an individual seed is an important strategy in achieving high yield at high population. Establishing mechanisms responsible for the greatest yields via high population under light‐enriched conditions, may provide insights for management and phenotypic improvement.
Haplotype analysis of β‐actin gene for its association with sperm quality and boar fertility
Authors: Lin C.‐L. , Jennen D.G.J. , Ponsuksili S. , Tholen E. , Tesfaye D. , Schellander K. , Wimmers K. 
Published: November 2006

Summary β‐actin (ACTB) was examined as a direct functional candidate gene for the possible association with sperm concentration, motility (MOT), semen volume per ejaculate, plasma droplet rate, abnormal sperm rate (ASR) and the fertility traits, non‐return rate and number of piglets born alive (NBA). Three polymorphisms in intron 3 (T>C) and one polymorphism in exon 4 (T>C) of porcine ACTB gene were identified by comparative sequencing of animals of the breeds Pietrain and Hampshire. Association analysis revealed that haplotypes affected the variation of the traits MOT, ASR and NBA. The beneficial haplotypes may provide considerable improvement of sperm quality and fertility in the tested commercial boar population.
The effect of Ruppia cirrhosa features on macroalgae and suspended matter in a Mediterranean shallow system
Authors: Mannino Anna Maria , Sarà Gianluca 
Published: November 2006

AbstractRelationships among chemical–physical features, total gross suspended organic matter, coverage of the seagrass Ruppia cirrhosa and its associated algal community in eight ponds of a saltworks system of western Sicily (Mediterranean Sea) were investigated in spring and summer 2004. All biological features varied both at different levels of seagrass coverage and between seasons. A low algal diversity (46 taxa, 14.75 ± 1.41 on average) was highlighted; algal coverage and species richness showed to be negatively correlated. Ruppia cirrhosa coverage was negatively correlated with algal coverage, but positively correlated with species richness. Moreover, a significant correlation among R. cirrhosa coverage, the availability of suspended matter in the water column and the chlorophyll a concentration was detected.