bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of Alternative Coding Schemes on Incidence Rates of Key Complications After Total Hip Arthroplasty
Authors: Cram Peter , Ibrahim Said A. , Lu Xin , Wolf Brian R.
Published: April 2012

Background: Administrative data are commonly used to examine orthopedic outcomes including total hip arthroplasty (THA), but little is known about how minor analytic decisions impact results. Our objective was to examine how the rates of 3 adverse outcomes (deep vein thrombosis [DVT], pulmonary embolism [PE], and hemorrhage) varied with subtle adjustments to our analytic method.Methods: We used Medicare Part A data to identify all beneficiaries who underwent primary or revision THA during 2007 to 2008. We used 2 published algorithms (Katz/Cram and Patient Safety Indicators [PSIs]) to identify cases of DVT, PE, and hemorrhage occurring at 3 different points in time; index admission; 30-day readmission; and index admission plus readmission. We used the kappa statistic to compare the agreement between methods. We examined variation in complication rates across hospitals using regression models that adjusted for differences in patient demographics and comorbidity. Results: Among 202 773 primary and 40 973 revision THA patients, the agreement between the Katz/Cram and PSI methods was excellent for DVT and PE at all time points (kappa 0.95-1.0) but poor for hemorrhage (kappa 0.07-0.29). The incidence of DVT during the index admission among the primary THA cohort was 0.40% using the Katz/Cram method and 0.37% using the PSI method. The incidence of hemorrhage during the index admission among the primary THA cohort was 1.29% using the Katz/Cram method and 0.05% using the PSI method. We found significant variation in hospital rates of all 3 complications (DVT, PE, and hemorrhage). For example, the mean rate of hemorrhage at index admission or readmission for revision THA was 5.7% (standard deviation: 12.8%); we found 137 hospitals with hemorrhage rates of 25% or higher among their revision THA patients. Discussion: We found important differences in the rates of THA complications depending upon the coding algorithms and time frame employed. Our results suggest that administrative data can be used to evaluate THA complications but that methodology should be carefully considered.
Barriers to Implementation of an Organized Geriatric Fracture Program
Authors: Kates Stephen L. , O’Malley Natasha , Friedman Susan M. , Mendelson Daniel A.
Published: April 2012

Introduction: There has been a recent increase in interest in implementing organized geriatric fracture programs for care of older adults with fragility fractures in order to improve both the quality and costs of care. Because such programs are relatively new, there are no standardized methods for implementation and no published descriptions of barriers to implementation. Materials and Methods: An online survey tool was sent to 185 surgeons and physicians practicing in the United States, who are involved with geriatric fracture care. Sixty-eight responses were received and evaluated. Results: Barriers identified included lack of medical and surgical leadership, need for a clinical case manager, lack of anesthesia department support, lack of hospital administration support, operating room time availability, and difficulty with cardiac clearance for surgery. Other issues important to implementation included quality improvement, cost reductions, cost to the hospital, infection prevention, readmission prevention, and dealing with competing interest groups and competing projects mandated by the government. Physicians and surgeons felt that a site visit to a functioning program was most important when considering implementing a hip fracture program. Conclusions: This study provides useful insights into barriers to implementing an organized hip fracture program. The authors offer suggestions on ways to mitigate or overcome these barriers.
Osteopontin is a prognostic factor for survival of acute myeloid leukemia patients
Authors: Liersch Ruediger , Gerss Joachim , Schliemann Christoph , Bayer Michael , Schwöppe Christian , Biermann Christoph , Appelmann Iris , Kessler Torsten , Löwenberg Bob , Büchner Thomas , Hiddemann Wolfgang , Müller-Tidow Carsten , Berdel Wolfgang E. , Mesters Rolf
Published: April 2012

Osteopontin (OPN) is a glycoprotein that is secreted by osteoblasts and hematopoietic cells. OPN suppresses the proliferation of hematopoietic stem cells in vitro and may regulate the hematopoietic stem cell pool. Increased serum OPN concentrations occur in chronic myeloid leukemia, multiple myeloma, and acute myeloid leukemia (AML). In the present study, we analyzed the prognostic impact of OPN in AML by investigating the expression and relevance of OPN in newly diagnosed AML patients from 2 large study groups (the German AML Cooperative Group and the Dutch-Belgian Hematology Oncology Cooperative group). IHC (n = 84), ELISAs of blood/BM sera (n = 41), and microarray data for mRNA levels (n = 261) were performed. Expression of OPN protein was increased in AML patients both in BM blasts (IHC) and in BM serum (ELISA) compared with healthy controls. Patients expressing high levels of OPN within the BM (IHC) experienced shortened overall survival (OS; P = .025). Multivariate analysis identified karyotype, blast clearance (day 16), and the level of OPN expression as independent prognostic factors for OS. This prompted us to analyze microarray data from 261 patients from a third cohort. The analysis confirmed OPN as a prognostic marker. In summary, high OPN mRNA expression indicated decreased event-free survival (P = .0002) and OS (P = .001). The prognostic role of OPN was most prominent in intermediate-risk AML. These data provide evidence that OPN expression is an independent prognostic factor in AML.
High prevalence of antibiotic resistance in commensal Escherichia coli among children in rural Vietnam
Authors: Dyar Oliver James , Hoa Nguyen Quynh , Trung Nguyen V , Phuc Ho D , Larsson Mattias , Chuc Nguyen TK , Lundborg Cecilia Stålsby
Published: April 2012

Background

Commensal bacteria represent an important reservoir of antibiotic resistance genes. Few community-based studies of antibiotic resistance in commensal bacteria have been conducted in Southeast Asia. We investigated the prevalence of resistance in commensal Escherichia coli in preschool children in rural Vietnam, and factors associated with carriage of resistant bacteria.

Methods

We tested isolates of E. coli from faecal samples of 818 children aged 6-60 months living in FilaBavi, a demographic surveillance site near Hanoi. Daily antibiotic use data was collected for participating children for three weeks prior to sampling and analysed with socioeconomic and demographic characteristics extracted from FilaBavi's re-census survey 2007. Descriptive statistics were generated, and a logistic regression model was used to identify contributions of the examined factors.

Results

High prevalences of resistance were found to tetracycline (74%), co-trimoxazole (68%), ampicillin (65%), chloramphenicol (40%), and nalidixic acid (27%). Two isolates were resistant to ciprofloxacin. Sixty percent of isolates were resistant to three or more antibiotics. Recent sulphonamide use was associated with co-trimoxazole resistance [OR 3.2, 95% CI 1.8-5.7], and beta-lactam use with ampicillin resistance [OR 1.8, 95% CI 1.3-2.4]. Isolates from children aged 6-23 months were more likely to be resistant to ampicillin [OR 1.8, 95% CI 1.3-2.4] and co-trimoxazole [OR 1.5, 95% CI 1.1-2.0]. Associations were identified between geographical areas and tetracycline and ampicillin resistance.

Conclusions

We present high prevalence of carriage of commensal E. coli resistant to commonly used antibiotics. The identified associations with recent antibiotic use, age, and geographical location might contribute to our understanding of carriage of antibiotic resistant commensal bacteria.
Seroprevalence of avian influenza A (H5N1) virus among poultry workers in Jiangsu Province, China: an observational study
Authors: Huo Xiang , Zu Rongqiang , Qi Xian , Qin Yuanfang , Li Liang , Tang Fenyang , Hu Zhibin , Zhu Fengcai
Published: April 2012

Background

Since 2003 to 06 Jan 2012, the number of laboratory confirmed human cases of infection with avian influenza in China was 41 and 27 were fatal. However, the official estimate of the H5N1 case-fatality rate has been described by some as an over estimation since there may be numerous undetected asymptomatic/mild cases of H5N1 infection. This study was conducted to better understand the real infection rate and evaluate the potential risk factors for the zoonotic spread of H5N1 viruses to humans.

Methods

A seroepidemiological survey was conducted in poultry workers, a group expected to have the highest level of exposure to H5N1-infected birds, from 3 counties with habitat lakes of wildfowl in Jiangsu province, China. Serum specimens were collected from 306 participants for H5N1 serological test. All participants were interviewed to collect information about poultry exposures.

Results

The overall seropositive rate was 2.61% for H5N1 antibodies. The poultry number was found associated with a 2.39-fold significantly increased subclinical infection risk after adjusted with age and gender.

Conclusions

Avian-to -human transmission of avian H5N1 virus remained low. Workers associated with raising larger poultry flocks have a higher risk on seroconversion.
New insights into Escherichia coli metabolism: carbon scavenging, acetate metabolism and carbon recycling responses during growth on glycerol
Authors: Martínez-Gómez Karla , Flores Noemí , Castañeda Héctor M , Martínez-Batallar Gabriel , Hernández-Chávez Georgina , Ramírez Octavio T , Gosset Guillermo , Encarnación Sergio , Bolivar Francisco
Published: April 2012

Background

Glycerol has enhanced its biotechnological importance since it is a byproduct of biodiesel synthesis. A study of Escherichia coli physiology during growth on glycerol was performed combining transcriptional-proteomic analysis as well as kinetic and stoichiometric evaluations in the strain JM101 and certain derivatives with important inactivated genes.

Results

Transcriptional and proteomic analysis of metabolic central genes of strain JM101 growing on glycerol, revealed important changes not only in the synthesis of MglB, LamB and MalE proteins, but also in the overexpression of carbon scavenging genes: lamB, malE, mglB, mglC, galP and glk and some members of the RpoS regulon (pfkA, pfkB, fbaA, fbaB, pgi, poxB, acs, actP and acnA). Inactivation of rpoS had an important effect on stoichiometric parameters and growth adaptation on glycerol. The observed overexpression of poxB, pta, acs genes, glyoxylate shunt genes (aceA, aceB, glcB and glcC) and actP, suggested a possible carbon flux deviation into the PoxB, Acs and glyoxylate shunt. In this scenario acetate synthesized from pyruvate with PoxB was apparently reutilized via Acs and the glyoxylate shunt enzymes. In agreement, no acetate was detected when growing on glycerol, this strain was also capable of glycerol and acetate coutilization when growing in mineral media and derivatives carrying inactivated poxB or pckA genes, accumulated acetate. Tryptophanase A (TnaA) was synthesized at high levels and indole was produced by this enzyme, in strain JM101 growing on glycerol. Additionally, in the isogenic derivative with the inactivated tnaA gene, no indole was detected and acetate and lactate were accumulated. A high efficiency aromatic compounds production capability was detected in JM101 carrying pJLBaroG

fbr

tktA, when growing on glycerol, as compared to glucose.

Conclusions

The overexpression of several carbon scavenging, acetate metabolism genes and the absence of acetate accumulation occurred in JM101 cultures growing on glycerol. To explain these results it is proposed that in addition to the glycolytic metabolism, a gluconeogenic carbon recycling process that involves acetate is occurring simultaneously in this strain when growing on glycerol. Carbon flux from glycerol can be efficiently redirected in JM101 strain into the aromatic pathway using appropriate tools.
Can slide positivity rates predict malaria transmission?
Authors: Bi Yan , Hu Wenbiao , Liu Huaxin , Xiao Yujiang , Guo Yuming , Chen Shimei , Zhao Laifa , Tong Shilu
Published: April 2012

Background

Malaria is a significant threat to population health in the border areas of Yunnan Province, China. How to accurately measure malaria transmission is an important issue. This study aimed to examine the role of slide positivity rates (SPR) in malaria transmission in Mengla County, Yunnan Province, China.

Methods

Data on annual malaria cases, SPR and socio-economic factors for the period of 1993 to 2008 were obtained from the Center for Disease Control and Prevention (CDC) and the Bureau of Statistics, Mengla, China. Multiple linear regression models were conducted to evaluate the relationship between socio-ecologic factors and malaria incidence.

Results

The results show that SPR was significantly positively associated with the malaria incidence rates. The SPR (β = 1.244, p = 0.000) alone and combination (SPR, β = 1.326, p < 0.001) with other predictors can explain about 85% and 95% of variation in malaria transmission, respectively. Every 1% increase in SPR corresponded to an increase of 1.76/100,000 in malaria incidence rates.

Conclusion

SPR is a strong predictor of malaria transmission, and can be used to improve the planning and implementation of malaria elimination programmes in Mengla and other similar locations. SPR might also be a useful indicator of malaria early warning systems in China.
Analysis of terminal duct lobular unit involution in luminal A and basal breast cancers
Authors: Yang Xiaohong R , Figueroa Jonine D , Falk Roni T , Zhang Hong , Pfeiffer Ruth M , Hewitt Stephen M , Lissowska Jolanta , Peplonska Beata , Brinton Louise , Garcia-Closas Montserrat , Sherman Mark E
Published: April 2012

Introduction

Involution of terminal duct lobular units (TDLUs), the structures that give rise to most breast cancers, has been associated with reduced breast cancer risk. Data suggest that the etiology and pathogenesis of luminal A and core basal phenotype (CBP) breast cancers differ, but associations with TDLU involution are unknown. Accordingly, we performed a masked microscopic assessment of TDLU involution in benign tissues associated with luminal A and CBP breast cancers diagnosed among women less than age 55 years.

Methods

Cases were participants in a population-based case-control study conducted in Poland. Increased TDLU involution was defined as fewer acini per TDLU or shorter TDLU diameter. Luminal A was defined as estrogen receptor (ER) positive and/or progesterone receptor (PR) positive and human epidermal growth factor receptor 2 (HER2) negative and CBP as negative for ER, PR, and HER2 with expression of basal cytokeratins or epidermal growth factor receptor (EGFR). We performed logistic regression to evaluate associations between TDLU involution and tumor subtypes, adjusted for clinical characteristics and breast cancer risk factors.

Results

Among 232 luminal A and 49 CBP cancers associated with evaluable TDLUs, CBP tumors were associated with significantly greater average number of acini per TDLU (odds ratio (OR) = 3.36, 95% confidence interval (CI) = 1.36 to 8.32, P = 0.009) and larger average TDLU diameter (OR = 2.49, 95% CI = 1.08 to 5.74, P = 0.03; comparing highest to lowest group, adjusted for age and study site).

Conclusions

We suggest that TDLU involution is less marked in benign tissues surrounding CBP as compared to luminal A cancers, which may reflect differences in the etiology and pathogenesis of these tumor subtypes.
Risk factors for acute organ failure in intensive care unit patients who receive respiratory support in the absence of non-respiratory organ failure: an international prospective cohort study
Authors: Terblanche Marius , Kruger Peter , Gangi Stefania di , Gearay Sadiq , Gilfeather Lynn , Ferguson Niall D , Pearse Rupert , Beale Richard , Rhodes Andrew , Brett Stephen J , McAuley Daniel F
Published: April 2012

Introduction

Many supposed low-risk intensive care unit (ICU) admissions develop acute organ failure (AOF). Identifying patients at high risk of developing AOF and targeting them with preventative strategies may be effective. Our study question was: in a population of ICU patients receiving positive pressure respiratory support (invasive or non-invasive) in the absence of non-respiratory AOF, what is the 14-day incidence of, risk factors for and time to acute organ failure?

Methods

In an international prospective cohort study, patients receiving positive pressure respiratory support (invasive or non-invasive) in the absence of non-respiratory AOF were enrolled and followed for 14 days. The primary outcome measure was the incidence of any AOF (defined as SOFA 3 to 4) during follow-up.

Results

A total of 123 of 766 screened patients (16.1%) were enrolled. Data are reported for 121 patients. In total, 45 out of 121 patients (37.2%) developed AOF. Mortality rates were higher in those with AOF: 17.8% versus 4.0% OR 5.11, P = 0.019) for ICU mortality; and 28.9% versus 11.8% (OR 2.80, P = 0.019) for hospital mortality. Median ICU length of stay was also longer in those with AOF (11 versus 3.0 days; P < 0.0001). Hypoxemic respiratory failure (P = 0.001) and cardiovascular dysfunction (that is, SOFA 1 to 2; P = 0.03) were associated with AOF. The median time to first AOF was two days.

Conclusions

Patients receiving positive (invasive or non-invasive) pressure respiratory support in the absence of non-respiratory AOF are commonly admitted to ICU; AOF is frequent in these patients. Organ failure developed within a short period after admission. Hypoxemic respiratory failure and cardiovascular dysfunction were strongly associated with AOF.
Safety of Low Doses of Quetiapine When Used for Insomnia
Authors: Coe Holly V , Hong Irene S
Published: April 2012

Objective:

To evaluate the safety of low doses of quetiapine when used for insomnia.

Data Sources:

A literature search was performed using PubMed and EMBASE (January 1990-November 2011) using the terms quetiapine, insomnia, sleep, low-dose, subtherapeutic, safety, and weight gain.

Study Selection And Data Extraction::

Two prospective trials were identified that evaluated the effect of quetiapine in primary insomnia. In addition, 2 retrospective cohort studies were identified that evaluated the safety of low doses of quetiapine when used for Insomnia. Several case reports on adverse effects with low doses of the drug were also Included.

Data Synthesis:

Quetiapine is commonly used off-label for treatment of insomnia. When used for sleep, doses typically seen are less than the Food and Drug Administration-recommended dosage of 150-800 mg/day; those evaluated in the studies reviewed here were 25-200 mg/day). At recommended doses, atypical antipsychotics such as quetiapine are associated with metabolic adverse events (diabetes, obesity, hyperlipidemia). Adverse effects in the prospective trials were patient-reported and were minor, including drowsiness and dry mouth; however, tha trials were limited by their small sample size and short duration. The retrospective cohort studies found that quetiapine was associated with significant increases in weight compared to baseline. Serious adverse events identified from case reports included fatal hepatotoxicity, restless legs syndrome, akathisia, and weight gain.

Conclusions:

There are potential safety concerns when using low-dose quetiapine for treatment of insomnia. These concerns should be evaluated in further prospective studies. Based on limited data and potential safety concerns, use of low-dose quetiapine for insomnia is not recommended.
Factors Associated with Reported Preventable Adverse Drug Events: A Retrospective, Case-Control Study
Authors: Beckett Robert D , Sheehan Amy Heck , Reddan Jennifer G
Published: April 2012

Background:

It has been reported that error occurs at some point during the medication use process in approximately 6% of medication doses administered in the inpatient setting. An estimated 1-10% of medication errors lead to patient harm; however, factors affecting the risk of harm from a medication error are undefined in the literature.

Objective:

To identify independent factors affecting the risk of reported preventable adverse drug events (ADEs) (ie, medication errors contributing to patient harm) compared to medication errors that did not contribute to patient harm in a diverse patient population.

Methods:

This was a retrospective, case-control study conducted at 3 hospitals within a large health system. Medication error reports from July 1, 2009, through June 30, 2010, were assessed. All reported medication errors determined to have contributed to patient harm were matched 1:1 with a medication error that did not contribute to harm. Data collected through review of the incident report and medical record included patient, provider, medication, and other related factors. Multivariable logistic regression was used to determine the relationship of potential factors to patient harm.

Results:

Of 4321 medication errors reported at study sites, 182 (4%) contributed to patient harm. Factors associated with increased independent risk of harm were 30-day readmission, time of day 0300-0659, and Institute for Safe Medication Practices (ISMP) high-alert medications. Factors associated with decreased independent risk of harm were multiple medication errors, occurrence during February or April, dispensing errors, and pharmacist review of medication order.

Conclusions:

Health systems should develop programs to promote safe, conscientious use of ISMP high-alert medications, promote pharmacist review, control the use of cabinet overrides, and direct provider attention toward recently admitted patients. Efforts should be made to determine factors associated with risk of harm at local levels.
Spontaneous Activity Promotes Synapse Formation in a Cell-Type-Dependent Manner in the Developing Retina
Authors: Soto Florentina , Ma Xiaofeng , Cecil Jacob L. , Vo Bradly Q. , Culican Susan M. , Kerschensteiner Daniel
Published: April 2012

Spontaneous activity is thought to regulate synaptogenesis in many parts of the developing nervous system.In vivoevidence for this regulation, however, is scarce and comes almost exclusively from experiments in which normal activity was reduced or blocked completely. Thus, whether spontaneous activity itself promotes synaptogenesis or plays a purely permissive role remains uncertain. In addition, how activity influences synapse dynamics to shape connectivity and whether its effects among neurons are uniform or cell-type-dependent is unclear. In mice lacking the cone–rod homeobox gene (Crx), photoreceptors fail to establish normal connections with bipolar cells (BCs). Here, we find that retinal ganglion cells (RGCs) inCrx−/−mice become rhythmically hyperactive around the time of eye opening as a result of increased spontaneous glutamate release from BCs. This elevated neurotransmission enhances synaptogenesis between BCs and RGCs, without altering the overall circuit architecture. Using live imaging, we discover that spontaneous activity selectively regulates the rate of synapse formation, not elimination, in this circuit. Reconstructions of the connectivity patterns of three BC types with a shared RGC target further revealed that neurotransmission specifically promotes the formation of multisynaptic appositions from one BC type without affecting the maintenance or elimination of connections from the other two. Although hyperactivity inCrx−/−mice persists, synapse numbers do not increase beyond 4 weeks of age, suggesting closure of a critical period for synaptic refinement in the inner retina. Interestingly, despite their hyperactivity, RGC axons maintain normal eye-specific territories and cell-type-specific layers in the dorsal lateral geniculate nucleus.
Neurogenic Subventricular Zone Stem/Progenitor Cells Are Notch1-Dependent in Their Active But Not Quiescent State
Authors: Basak Onur , Giachino Claudio , Fiorini Emma , MacDonald H. Robson , Taylor Verdon
Published: April 2012

The adult mammalian forebrain contains neural stem/progenitor cells (NSCs) that generate neurons throughout life. As in other somatic stem cell systems, NSCs are proposed to be predominantly quiescent and proliferate only sporadically to produce more committed progeny. However, quiescence has recently been shown not to be an essential criterion for stem cells. It is not known whether NSCs show differences in molecular dependence based on their proliferation state. The subventricular zone (SVZ) of the adult mouse brain has a remarkable capacity for repair by activation of NSCs. The molecular interplay controlling adult NSCs during neurogenesis or regeneration is not clear but resolving these interactions is critical in order to understand brain homeostasis and repair. Using conditional genetics and fate mapping, we show that Notch signaling is essential for neurogenesis in the SVZ. By mosaic analysis, we uncovered a surprising difference in Notch dependence between active neurogenic and regenerative NSCs. While both active and regenerative NSCs depend upon canonical Notch signaling,Notch1-deletion results in a selective loss of active NSCs (aNSCs). In sharp contrast, quiescent NSCs (qNSCs) remain afterNotch1ablation until induced during regeneration or aging, whereupon they become Notch1-dependent and fail to fully reinstate neurogenesis. Our results suggest that Notch1 is a key component of the adult SVZ niche, promoting maintenance of aNSCs, and that this function is compensated in qNSCs. Therefore, we confirm the importance of Notch signaling for maintaining NSCs and neurogenesis in the adult SVZ and reveal that NSCs display a selective reliance on Notch1 that may be dictated by mitotic state.
Ferritin Stimulates Oligodendrocyte Genesis in the Adult Spinal Cord and Can Be Transferred from Macrophages to NG2 CellsIn Vivo
Authors: Schonberg David L. , Goldstein Evan Z. , Sahinkaya Fatma Rezan , Wei Ping , Popovich Phillip G. , McTigue Dana M.
Published: April 2012

Injured CNS tissue often contains elevated iron and its storage protein ferritin, which may exacerbate tissue damage through pro-oxidative mechanisms. Therefore, therapeutic studies often target iron reduction as a neuroprotective strategy. However, iron may be crucial for oligodendrocyte replacement and remyelination. For instance, we previously showed that intraspinal toll-like receptor 4 macrophage activation induced the generation of new ferritin-positive oligodendrocytes, and that iron chelation significantly reduced this oligodendrogenic response. Since macrophages can secrete ferritin, we hypothesize that ferritin is a macrophage-derived signal that promotes oligodendrogenesis. To test this, we microinjected ferritin into intact adult rat spinal cords. Within 6 h, NG2+ progenitor cells proliferated and accumulated ferritin. By 3 d, many of these cells had differentiated into new oligodendrocytes. However, acute neuron and oligodendrocyte toxicity occurred in gray matter. Interestingly, ferritin-positive NG2 cells and macrophages accumulated in the area of cell loss, revealing that NG2 cells thrive in an environment that is toxic to other CNS cells. To test whether ferritin can be transferred from macrophages to NG2 cellsin vivo, we loaded macrophages with fluorescent ferritin then transplanted them into intact spinal white matter. Within 3–6 d, proliferating NG2 cells migrated into the macrophage transplants and accumulated fluorescently labeled ferritin. These results show that activated macrophages can be anin vivosource of ferritin for NG2 cells, which induces their proliferation and differentiation into new oligodendrocytes. This work has relevance for conditions in which iron-mediated injury and/or repair likely occur, such as hemorrhage, stroke, spinal cord injury, aging, Parkinson's disease, and Alzheimer's disease.
Distinct Subsets of Syt-IV/BDNF Vesicles Are Sorted to Axons versus Dendrites and Recruited to Synapses by Activity
Authors: Dean Camin , Liu Huisheng , Staudt Thorsten , Stahlberg Markus A. , Vingill Siv , Bückers Johanna , Kamin Dirk , Engelhardt Johann , Jackson Meyer B. , Hell Stefan W. , Chapman Edwin R.
Published: April 2012

BDNF plays a critical role in the regulation of synaptic strength and is essential for long-term potentiation, a phenomenon that underlies learning and memory. However, whether BDNF acts in a diffuse manner or is targeted to specific neuronal subcompartments or synaptic sites to affect circuit function remains unknown. Here, using photoactivation of BDNF or syt-IV (a regulator of exocytosis present on BDNF-containing vesicles) in transfected rat hippocampal neurons, we discovered that distinct subsets of BDNF vesicles are targeted to axons versus dendrites and are not shared between these compartments. Moreover, syt-IV- and BDNF-harboring vesicles are recruited to both presynaptic and postsynaptic sites in response to increased neuronal activity. Finally, using syt-IV knockout mouse neurons, we found that syt-IV is necessary for both presynaptic and postsynaptic scaling of synaptic strength in response to changes in network activity. These findings demonstrate that BDNF-containing vesicles can be targeted to specific sites in neurons and suggest that syt-IV-regulated BDNF secretion is subject to spatial control to regulate synaptic function in a site-specific manner.
Mechanisms of Action Selection and Timing in Substantia Nigra Neurons
Authors: Fan David , Rossi Mark A. , Yin Henry H.
Published: April 2012

The timing of actions is critical for adaptive behavior. In this study we measured neural activity in the substantia nigra as mice learned to change their action duration to earn food rewards. We observed dramatic changes in single unit activity during learning: both dopaminergic and GABAergic neurons changed their activity in relation to behavior to reflect the learned instrumental contingency and the action duration. We found the emergence of “action-on” neurons that increased firing for the duration of the lever press and mirror-image “action-off” neurons that paused at the same time. This pattern is especially common among GABAergic neurons. The activity of many neurons also reflected confidence about the just completed action and the prospect of reward. Being correlated with the relative duration of the completed action, their activity could predict the likelihood of reward collection. Compared with the GABAergic neurons, the activity of dopaminergic neurons was more commonly modulated by the discriminative stimulus signaling the start of each trial, suggesting that their phasic activity reflected sensory salience rather than any reward prediction error found in previous work. In short, these results suggest that (1) nigral activity is highly plastic and modified by the learning of the instrumental contingency; (2) GABAergic output from the substantia nigra can simultaneously inhibit and disinhibit downstream structures, while the dopaminergic output also provide bidirectional modulation of the corticostriatal circuits; (3) dopaminergic and GABAergic neurons show similar task-related activity, although DA neurons are more responsive to the trial start signal.
On the Complexation of Some Divalent Metal Cations with Beauvericin in Nitrobenzene Saturated with Water
Authors: Makrlík Emanuel , Selucký P. , Vaňura P. , Toman Petr
Published: April 2012

From extraction experiments and γ-activity measurements, the exchange extraction constants corresponding to the general equilibrium M2+(aq)+1·Sr2+(nb)⇆1·M2+(nb)+ Sr2+(aq) taking place in the two–phase water-nitrobenzene system (M2+ߙ=ߙMg2+, Ca2+, Ba2+, Pb2+, Zn2+, Mn2+; 1ߙ=ߙbeauvericin; aqߙߙ=ߙaqueous phase, nbߙ=ߙnitrobenzene phase) were determined. Moreover, the stability constants of the 1·M2+ complexes in water-saturated nitrobenzene were calculated; they were found to increase in the cation series of Mg2+, Zn2+< Mn2+< Pb2+< Ba2+< Ca2+.
Comparative evaluation of local and improved crop varieties through farmers’ participation on resource-poor farms in Afghanistan
Authors: Rizvi S. , Sharma R. , Srinivas T. , Manan A. , Osmanzai A. , Siddiqui S. , Wadan K. , Hakimi N. , Rahmani A.
Published: April 2012

The introduction of new crop varieties is important to improve farm productivity and increase food security in developing countries. This study was conducted to determine the performance of improved varieties of wheat (Triticum aestivum L.), rice (Oryza sativa L.), mungbean [(Vigna radiata (L.) Wilczek] and potato (Solanum tuberosum L.) in comparison to local varieties through farmers’ participatory evaluation. The study was conducted during three years (2006 to 2008) with 948 farmers’ participatory field trials across 18 districts in three Eastern provinces (Nangarhar, Laghman and Kunar) of Afghanistan. One or more improved varieties of wheat, rice, mungbean and potato were compared to the most popular local variety. Data were recorded on the grain yield of wheat, rice and mungbean, and the tuber yield of potato. On average, the improved varieties outyielded local varieties by 69, 57, 70 and 65% for wheat, rice, mungbean, and potato, respectively. Economic analysis in terms of net benefit demonstrated that the adoption of improved varieties resulted in additional incomes of US$ 1840, 1299, 574 and 790 ha-1 for wheat, rice, mungbean and potato, respectively. These findings underline the importance of on-farm farmers’ participatory technology evaluation in developing countries to disseminate new crop varieties to improve farm productivity.
Comparison of soil microbial communities from two distinct karst areas in Hungary
Authors: Knáb Mónika , Szili-Kovács Tibor , Kiss Klaudia , Palatinszky Márton , Márialigeti Károly , Móga János , Borsodi Andrea
Published: April 2012

Karst areas belong to the most exposed terrestrial ecosystems, therefore their study have a priority task in Hungary, as well. The aim of this study was to compare the structure, activity and diversity of soil microbial communities from two distinct Hungarian karst areas (Aggtelek NP and Tapolca-basin). Soil samples were taken three times from 6 distinct sites, from different depths. Soil microbial biomass C (MBC), microbial biomass N (MBN), basal respiration (BRESP) and substrate induced respiration (SIR) were measured. The phylogenetic diversity of bacterial communities was compared by Denaturing Gradient Gel Electrophoresis (DGGE). The highest MBC, MBN, BRESP and SIR values were measured in the rendzina soil from Aggtelek. On the basis of biomass and respiration measurements, microbial communities differentiated mainly according to soil depths whereas DGGE profiles of bacterial communities resulted in groups mainly according to sampling sites.
Synthesis of Colloidal InP/ZnS Nanocrystals for a Photosensitizer
Authors: Lee Seungyong , Reddy Vanga R. , Wu Jiang , Eyi Rick , Manasreh Omar
Published: April 2012

Its intrinsic nontoxicity makes the direct band gap InP/ZnS core/shell be one of the most promising semiconductor nanocrystals for optoelectric applications, with the advantage of tuning the optical absorption range in the desired solar spectrum region. Highly luminescent and monodisperse InP/ZnS nanocrystals were synthesized in a non-coordinating solvent under a thorough degassing process. By varying synthesis scheme, different size InP/ZnS nanocrystals were grown. For the purpose of ensuring air stability, ZnS shell was grown. This ZnS shell improves the chemical stability in terms of oxidation prevention. Measurements of absorption and emission were performed on different InP/ZnS nanocrystals with different sizes. As expected, the measurements show a red-shift as the size of the InP/ZnS nanocrystals increased.
Effects of planting density on flower production in carnation crop
Authors: Souza Maria Alice de Lourdes Bueno , Simão Salim
Published: April 2012

The influence of density of planting on flower production of carnation plants grown in vinil houses, was studied. Planting densities of 233,333; 175,000 and 116,667 plants per hectare were obtained by using planting spacings of 0.20 m between rows and 0.15 m, 0,20 m and 0.30 m between plants. Data were taken on total number of flowers per plant and per hectare. As far as planting densities are concerned, there was an increase of total flower production per hectare and a decrease of slower production per plant.
Accumulation of dry matter and macronutrients by two varieties of sweet sorghum
Authors: Rosolem C.A. , Malavolta E.
Published: April 2012

Samples of two varieties of sweet .sorghum (Brandes and Rio) grown on a Dark Red Latosol (Barra Bonita, SP) were collected and analysed (dry matter and macronutrient contents) at intervals of 20 days. Both varieties showed faster uptake of most of the nutrients between flower initiation and head formation. Variety Brandes, in said period, took up more nutrients per day than the other, although its cycle was longer.
A comparative study on production of five soybean (Glycine max (L.) Merrill) cultivars
Authors: Castro Paulo R.C.
Published: April 2012

Under greenhouse conditions cultivars Davis, IAC 73-228, PI 227.687, PI 171.451, and PI 229.358 of soybean were compared. PI 171.451 showed lower dry weight of stem in relation to Davis. Higher pod numbers produced by PI 227-687, IAC 73-228, and PI 229. 358 as compared to Davis were observed. Cultivars PI 227.687 and IAC 73-228 produced larger seed numbers. A larger weight of 100 seeds in Davis, PI 229.358, and PI 171. 45I cultivars was observed. The last two cultivars are sources of resistance against pests of soybean.
An evaluation of natural infestation by leaf pests on soybean (Glycine max (L.) Merrill) cultivars
Authors: Castro Paulo R.C.
Published: April 2012

Damage caused by leaf pests of soybean on five cultivars was evaluated. Afield experiment was carried out at the Piracicaba region, cultivars Davis, IAC 73-228, PI 227.687,PI 171.451, and PI 229.358 having been compared. Leaf damage was produced by natural infestation of Anticarsia gemmatalis and Plusia sp. Cultivar PI 171.451 showed lower comsumption of leaves in relation to control ('Davis') and other cultivars. Damage was more serious on IAC 73-228 than on PI 227.687 and PI 229.358.
Effects of nutrient foliar sprays containing growth regulators on productivity of peanut (Arachis hypogaea L. cv. Tatu-53)
Authors: Castro Paulo R.C. , Paro Paulo H.
Published: April 2012

The effects of the application of a macronutrient foliar spray combined with micronutrients and growth regulators (Unifol) on peanut grown in a soil with high fertility were investigated. A control without fertilizer and a soil fertilization (250 kg/ha) with NPK 9-30-16 were also established. Other treatments were as follows: Unifol fertilizer (18-12 16) applied 23 days after germination: Unifol (18-12-6) applied at the beginning of flowering; Unifol (18-12-6) applied during flowering, and Unifol (18-12-6) applied 23 days after germination plus Unifol (7-23-7) at the beginning of flowering. No significant differences were found amongst treatments, but certain treatments showed higher productivity e given Unifol fertilizer (18-12-6) applied 23 days after germination plus Unifol (7-23-7) at the flower anthesis. In this treatment, the number of pods, weight of seeds and production of seeds were higher. Best production of forage occurred in the treatment receiving soil fertilization.
Variação das características pedológicas e classificação taxonômica de argissolos derivados de rochas sedimentares
Authors: Pedron Fabrício de Araújo , Samuel-Rosa Alessandro , Dalmolin Ricardo Simão Diniz
Published: April 2012

Trabalhos têm apontado demandas em relação ao conhecimento da variação pedológica de Argissolos. Essa variação pode ser analisada pela estatística multivariada - também responsável pela classificação numérica dos dados. A comparação entre a classificação numérica e a classificação hierárquica pode contribuir para a evolução do Sistema Brasileiro de Classificação de Solos (SiBCS). Os objetivos deste trabalho foram analisar a variação pedológica de Argissolos derivados de materiais sedimentares na Depressão Central do Rio Grande do Sul e validar a estrutura da ordem dos Argissolos do SiBCS por meio da interpretação da classificação numérica. Foram considerados 42 perfis de Argissolos derivados da Formação Santa Maria e da Formação Caturrita, na região central do Rio Grande do Sul. O estudo foi realizado por meio da análise das componentes principais e da análise de agrupamento. Foram determinadas cinco componentes principais, com poder de explicação de 84,3 % da variância dos dados, representadas de um a cinco pelas variáveis: teor de areia, matiz (cor), saturação por bases, atividade da argila e teor de C orgânico total. A análise de agrupamento separou os perfis de Argissolos em três grupos principais. O grupo A apresentou perfis com drenagem deficiente, derivados das três rochas consideradas neste trabalho. O grupo B, derivado exclusivamente dos arenitos das Formações Santa Maria e Caturrita, mostrou perfis bem drenados, porém com menor teor de argila, maior gradiente textural e menor capacidade de troca de cátions potencial em relação ao grupo C. Este grupo apresentou perfis bem drenados, alíticos e com teores de argila superiores em relação aos demais grupos, derivados, predominantemente, do lamito da Formação Santa Maria. A classificação numérica validou a estrutura do SiBCS para a ordem dos Argissolos. Contudo, a análise de agrupamento evidenciou aspectos morfológicos importantes e ainda não considerados pelo SiBCS em nível categórico elevado (grande grupo), como a variação na espessura e textura do horizonte A ou A + E, o teor de argila no horizonte B e o gradiente textural nos perfis de Argissolos.
Comparação de métodos convencional e alternativo para determinação de sódio, potássio e fósforo em extratos de solos obtidos com solução de mehlich-1
Authors: Soares Ricardo , Escaleira Viviane , Campos David Vilas Boas de , Monteiro Maria Inês Couto , Carneiro Manuel Castro , Santelli Ricardo Erthal , Bernardi Alberto Carlos de Campos
Published: April 2012

Foram comparadas as concentrações de Na, K e P em extratos de solos, obtidas por um método de extração convencional, no qual é utilizada uma razão solo:extrator (Mehlich-1) de 1:10, com aquelas encontradas utilizando uma razão solo:extrator (Mehlich-1) de 1:5. Também, foram comparados os resultados obtidos por técnicas de quantificação convencionais, nas quais Na e K são quantificados por fotometria de chama e P por espectrofotometria de absorção molecular, com aqueles encontrados por espectrometria de emissão óptica com plasma indutivamente acoplado (ICP OES). Foram analisadas 15 amostras de solo brasileiro. No estudo de repetibilidade aplicado a todos os resultados, os maiores CVs foram encontrados para P e Na, principalmente quando as concentrações dos analitos foram menores (< 9 mg dm-3 para P e < 10 mg dm-3 para Na). Esse fato foi devido provavelmente à heterogeneidade dos extratos, que continham partículas coloidais. Filtração ou centrifugação em vez de decantação dos extratos provavelmente resultaria em menores CVs. No estudo de reprodutibilidade, realizado para três amostras, foram obtidos resultados não reprodutíveis somente para K em uma amostra. Todos os resultados obtidos por ICP OES foram semelhantes aos obtidos por espectrofotometria de absorção molecular UV-Vis. e fotometria de chama, indicando que a primeira técnica foi adequada para determinação de Na, K e P nos extratos de solos tropicais obtidos com solução de Mehlich-1. Os resultados de Na, K e P obtidos com razão solo:extrator de 1:5 foram estatisticamente diferentes daqueles em que se utilizou razão solo:extrator de 1:10. A maioria dos resultados obtidos com razão solo:extrator de 1:5 foi menor que os obtidos com razão solo:extrator 1:10, sobretudo nas amostras com concentrações de analitos mais elevadas. Portanto, para estudos comparativos envolvendo macronutrientes, deve-se utilizar o método convencional com razão solo:extrator de 1:10.
Acurácia e calibração de sonda de capacitância em Latossolo Vermelho cultivado com cafeeiro
Authors: Silva Bruno Montoani , Oliveira Geraldo César de , Serafim Milson Evaldo , Silva Júnior João José da , Colombo Alberto , Lima José Maria de
Published: April 2012

O objetivo deste trabalho foi determinar a acurácia da sonda de multisensores de capacitância "Delta-T Profile probe PR2/6", na avaliação do conteúdo de água do solo com uso de calibrações padrão do fabricante, realizar a calibração para condições específicas de locais e profundidades de amostragem do solo e obter coeficientes de calibração para medições acuradas em tempo real. Em janeiro de 2010, foram coletadas amostras de solo com estrutura preservada a diferentes profundidades, nas linhas de plantio do cafeeiro e nas entrelinhas. As análises foram realizadas em laboratório, com o sensor ML2x Theta probe. Após a obtenção das leituras do sensor, o teor de água foi determinado por meio do método gravimétrico. Foram utilizadas amostras de Latossolo Vermelho distrófico muito argiloso. As calibrações padrão do fabricante (mineral e orgânica) não não se mostraram adequadas para emprego nas condições de manejo (locais e profundidades de amostragem) avaliadas. Na impossibilidade de averiguar a acurácia obtida pelo método recomendado pelo fabricante, o uso de ajustes de regressão linear ou da ferramenta Solver mostrou-se útil no processo de calibração. São necessárias apenas duas equações de calibração para avaliação do teor de água das situações contrastantes de manejo.
Candidate SNPs for carcass and meat traits in Nelore animals and in their crosses with Bos taurus
Authors: Curi Rogério Abdallah , Krauskopf Monique Marcondes , Hadlich Janaína Conte , Fortes Marina Rufino Salinas , Vankan Dianne Margaret , Silva Josineudson Augusto II Vasconcelos , Oliveira Henrique Nunes de , Mota Marcílio Dias Silveira da
Published: April 2012

The objective of this work was to evaluate the effects of single-nucleotide polymorphisms (SNPs) in the genes IGF1 (AF_017143.1:g.198C>T), MSTN (AF_320998.1:g.433C>A), MYOD1 (NC_007313:g.1274A>G) and MYF5 (NC_007303:g.1911A>G) on carcass and meat traits in Nelore (Bos indicus) and Nelore x B. taurus. A total of 300 animals were genotyped and phenotyped for rib eye area (REA), backfat thickness (BT), intramuscular fat (IF), shear force (SF) and myofibrillar fragmentation index (MFI). The effects of allele substitution for each SNP were estimated by regression of the evaluated phenotypes on the number of copies of a particular allele using the general linear model. The polymorphism at IGF1 was non-informative in Nelore animals. In crossbred animals, the IGF1 C allele was associated with greater REA. However, this relation was not significant after Bonferroni correction for multiple testing. The A allele of the MSTN polymorphism was absent in Nelore cattle and was only found in two crossbred animals. The polymorphisms of MYOD1 and MYF5 were little informative in Nelore animals with G allele frequency of 0.097 and A allele frequency of 0.031, respectively. These markers show no association with the analyzed traits in the total sample of evaluated animals.