bluuebunny/crossref_metadata_2025 huggingface dataset:
TABASCO: A single molecule, base-pair resolved gene expression simulator
Authors: Kosuri Sriram , Kelly Jason R , Endy Drew
Published: December 2007

Background

Experimental studies of gene expression have identified some of the individual molecular components and elementary reactions that comprise and control cellular behavior. Given our current understanding of gene expression, and the goals of biotechnology research, both scientists and engineers would benefit from detailed simulators that can explicitly compute genome-wide expression levels as a function of individual molecular events, including the activities and interactions of molecules on DNA at single base pair resolution. However, for practical reasons including computational tractability, available simulators have not been able to represent genome-scale models of gene expression at this level of detail.

Results

Here we develop a simulator, TABASCO http://openwetware.org/wiki/TABASCO, which enables the precise representation of individual molecules and events in gene expression for genome-scale systems. We use a single molecule computational engine to track individual molecules interacting with and along nucleic acid polymers at single base resolution. Tabasco uses logical rules to automatically update and delimit the set of species and reactions that comprise a system during simulation, thereby avoiding the need for a priori specification of all possible combinations of molecules and reaction events. We confirm that single molecule, base-pair resolved simulation using TABASCO (Tabasco) can accurately compute gene expression dynamics and, moving beyond previous simulators, provide for the direct representation of intermolecular events such as polymerase collisions and promoter occlusion. We demonstrate the computational capacity of Tabasco by simulating the entirety of gene expression during bacteriophage T7 infection; for reference, the 39,937 base pair T7 genome encodes 56 genes that are transcribed by two types of RNA polymerases active across 22 promoters.

Conclusion

Tabasco enables genome-scale simulation of transcription and translation at individual molecule and single base-pair resolution. By directly representing the position and activity of individual molecules on DNA, Tabasco can directly test the effects of detailed molecular processes on system-wide gene expression. Tabasco would also be useful for studying the complex regulatory mechanisms controlling eukaryotic gene expression. The computational engine underlying Tabasco could also be adapted to represent other types of processive systems in which individual reaction events are organized across a single spatial dimension (e.g., polysaccharide synthesis).
The first trimester human trophoblast cell line ACH-3P: A novel tool to study autocrine/paracrine regulatory loops of human trophoblast subpopulations – TNF-α stimulates MMP15 expression
Authors: Hiden Ursula , Wadsack Christian , Prutsch Nicole , Gauster Martin , Weiss Ursula , Frank Hans-Georg , Schmitz Ulrike , Fast-Hirsch Christa , Hengstschläger Markus , Pötgens Andy , Rüben Angela , Knöfler Martin , Haslinger Peter , Huppertz Berthold , Bilban Martin , Kaufmann Peter , Desoye Gernot
Published: December 2007

Background

The trophoblast compartment of the placenta comprises various subpopulations with distinct functions. They interact among each other by secreted signals thus forming autocrine or paracrine regulatory loops. We established a first trimester trophoblast cell line (ACH-3P) by fusion of primary human first trimester trophoblasts (week 12 of gestation) with a human choriocarcinoma cell line (AC1-1).

Results

Expression of trophoblast markers (cytokeratin-7, integrins, matrix metalloproteinases), invasion abilities and transcriptome of ACH-3P closely resembled primary trophoblasts. Morphology, cytogenetics and doubling time was similar to the parental AC1-1 cells. The different subpopulations of trophoblasts e.g., villous and extravillous trophoblasts also exist in ACH-3P cells and can be immuno-separated by HLA-G surface expression. HLA-G positive ACH-3P display pseudopodia and a stronger expression of extravillous trophoblast markers. Higher expression of insulin-like growth factor II receptor and human chorionic gonadotropin represents the basis for the known autocrine stimulation of extravillous trophoblasts.

Conclusion

We conclude that ACH-3P represent a tool to investigate interaction of syngeneic trophoblast subpopulations. These cells are particularly suited for studies into autocrine and paracrine regulation of various aspects of trophoblast function. As an example a novel effect of TNF-α on matrix metalloproteinase 15 in HLA-G positive ACH-3P and explants was found.
Identification of a novel conserved mixed-isoform B56 regulatory subunit and spatiotemporal regulation of protein phosphatase 2A during Xenopus laevisdevelopment
Authors: Baek Sungmin , Seeling Joni M
Published: December 2007

Background

Wnt signaling is a key regulator of development and tumorigenesis. Protein phosphatase 2A (PP2A), which consists of a catalytic C, a structural A, and a regulatory B subunit, plays diverse roles in Wnt signaling through its B56 subunits. B56 is a multigene family encoding for proteins with a conserved core domain and divergent amino- and carboxy-termini. Ectopic B56α and B56γ reduce β-catenin abundance and B56α reduces Wnt-dependent transcription, suggesting that B56α and B56γ inhibit Wnt signaling. In contrast, B56ε is required for Wnt signaling. Knowledge of where and when B56 subunits are expressed during Xenopus development will aid in our understanding of their roles in Wnt signaling.

Results

We have undertaken expression analyses of B56α and B56γ in Xenopus laevis. We cloned Xenopus B56α; it is 88% identical to human B56α. Xenopus B56γ is 94% identical with human B56γ, however, a novel evolutionarily conserved mixed-isoform transcript was identified that contains a B56δ-like amino-terminal domain and a B56γ core domain. The B56δ-like variable domain exon is located upstream of the B56γ variable domain exon at the human B56γ locus, suggesting that the mixed-isoform transcript is due to alternative splicing. B56γ transcripts with different 3' ends were identified that lack or possess a 35 base pair sequence, resulting in either a transcript similar to human B56γ1, or an uncharacterized evolutionarily conserved sequence. Real time RT-PCR analyses revealed that B56α is expressed at moderate levels before the midblastula transition (MBT), at reduced levels during gastrulation and neurulation, and at high levels during organogenesis, while B56γ is expressed at low levels until organogenesis. B56α is enriched in the ventral hemisphere pre-MBT, while B56γ is ventrally enriched post-MBT. Aα, Aβ, Cα and Cβ are expressed in early Xenopus development, suggesting the presence of a functional heterotrimer.

Conclusion

Our data suggest that B56 functional diversity is achieved in part through the synthesis of a novel mixed-isoform B56δ/γ transcript. Our data also suggest that B56α functions pre-MBT, inhibiting Wnt signaling on the ventral side of the embryo, and again during organogenesis, while B56γ functions primarily post-MBT.
Evidence for the Tonic Inhibition of Spinal Pain by Nicotinic Cholinergic Transmission through Primary Afferents
Authors: Matsumoto Misaki , Xie Weijiao , Inoue Makoto , Ueda Hiroshi
Published: December 2007

Background:

We have proposed that nerve injury-specific loss of spinal tonic cholinergic inhibition may play a role in the analgesic effects of nicotinic acetylcholine receptor (nAChR) agonists on neuropathic pain. However, the tonic cholinergic inhibition of pain remains to be well characterized.

Results:

Here, we show that choline acetyltransferase (ChAT) signals were localized not only in outer dorsal horn fibers (lamina I–III) and motor neurons in the spinal cord, but also in the vast majority of neurons in the dorsal root ganglion (DRG). When mice were treated with an antisense oligodeoxynucleotide (AS-ODN) against ChAT, which decreased ChAT signals in the dorsal horn and DRG, but not in motor neurons, they showed a significant decrease in nociceptive thresholds in paw pressure and thermal paw withdrawal tests. Furthermore, in a novel electrical stimulation-induced paw withdrawal (EPW) test, the thresholds for stimulation through C-, Aδ- and Aβ-fibers were all decreased by AS-ODN-pretreatments. The administration of nicotine (10 nmol i.t.) induced a recovery of the nociceptive thresholds, decreased by the AS-ODN, in the mechanical, thermal and EPW tests. However, nicotine had no effects in control mice or treated with a mismatch scramble (MS)-ODN in all of these nociception tests.

Conclusion:

These findings suggest that primary afferent cholinergic neurons produce tonic inhibition of spinal pain through nAChR activation, and that intrathecal administration of nicotine rescues the loss of tonic cholinergic inhibition.
Multi-modal-analgesia for pain management after Hallux Valgus surgery: a prospective randomised study on the effect of ankle block
Authors: Turan Ibrahim , Assareh Hamid , Rolf Christer , Jakobsson Jan
Published: December 2007

Background

Pain and emesis are the two major complaints after day case surgery. Local anaesthesia has become an important part of optimizing intra and post-operative pain treatment, but is sometimes not entirely sufficient. The aim of the present study was to study the effect of adding an ankle block to a multi-modal analgesic approach on the first 24-hour-need for rescue analgesia in patients undergoing elective Hallux Valgus surgery.

Type of study

Prospective, randomized patient-blind study comparing ankle block with levo-bupivacaine, lidocaine and Saline placebo control.

Methods

Ninety patients were studied comparing ankle block (15 cc) using levo-bupivacaine 2.5 mg/ml, lidocaine 10 mg/ml or placebo (saline) on day-case elective Hallux Valgus surgery, supported by general anaesthesia in all cases. Primary study endpoint was number of patient's requiring oral analgesics during the first 24 post-operative hours.

Results

Ankle block had no effect on need for rescue analgesia and pain ratings during the 1st24 postoperative hours, there was no difference seen between placebo and any of the two active local anaesthesia studied. The only differences seen was that both lidocaine and levo-bupivacaine reduced the intra-operative need for anaesthetic (sevoflurane) and that levo-bupivacaine patients had a lower need as compared to the lidocaine patients for oral analgesics during the afternoon of surgery.

Conclusion

Adding a single shot ankle block to a multi-modal pain management strategy reduces the need for intra-operative anaesthesia but has no major impact of need of rescue analgesics or pain during the first 24-hour after surgery.
New azimuthal binning for improved delineation of faults and fractures
Authors: Perez Gabriel , Marfurt Kurt J.
Published: December 2007

We suggest and test a new way to define azimuth binning in Kirchhoff prestack migration. With this new definition, we sort seismic data by the azimuth of the average travel path traversed from the source to the subsurface image point and back to the receiver, rather than the azimuth between source and receiver on the surface of the earth. This approach avoids mixing the typically weaker side-scattered energy with the stronger in-plane reflections, thereby providing greater leverage in identifying image contributions from out-of-the-plane steeply dipping reflectors, fractures and faults. We examine the impact of this new imaging approach combined with analysis of seismic attributes that have proved useful for fracture detection, on data from the Fort Worth Basin, Texas, United States. We find that the image of features such as reflectors and discontinuities focus into azimuths perpendicular to the strike of each feature. The discrimination achieved in the azimuthal domain allows for an increased resolution in analysis of geologic features according to their strike direction. It should also result in improved residual azimuthal velocity analysis.
Effects of Calcium and Vitamin D Supplementation on Hip Bone Mineral Density and Calcium-Related Analytes in Elderly Ambulatory Australian Women: A Five-Year Randomized Controlled Trial
Authors: Zhu Kun , Devine Amanda , Dick Ian M. , Wilson Scott G. , Prince Richard L.
Published: December 2007

Context: Effects of long-term calcium, with or without vitamin D, on hip bone mineral density (BMD) and bone turnover in sunny climates have not been reported.

Objective: The aim was to evaluate the effect of vitamin D added to calcium supplementation on hip dual-energy x-ray absorptiometry BMD and calcium-related analytes.

Design, Setting, and Participants: The study was a 5-yr randomized, controlled, double-blind trial of 120 community-dwelling women aged 70–80 yr.

Interventions: The interventions were 1200 mg/d calcium with placebo vitamin D (Ca group) or with 1000 IU/d vitamin D2 (CaD group), or double placebo (control).

Main Outcome Measures: Hip BMD, plasma 25-hydroxyvitamin D, biomarkers of bone turnover, PTH, and intestinal calcium absorption were measured.

Results: Hip BMD was preserved in CaD (−0.17%) and Ca (0.19%) groups but not controls (−1.27%) at yr 1 and maintained in the CaD group only at yr 3 and 5. The beneficial effects were mainly in those with baseline 25-hydroxyvitamin D levels below the median (68 nmol/liter). At yr 1, compared with controls, the Ca and CaD groups had 6.8 and 11.3% lower plasma alkaline phosphatase, respectively (P ≤ 0.02), and 28.7 and 34.5% lower urinary deoxypyridinoline to creatinine ratio, respectively (P ≤ 0.05). At 5 yr, this suppression was maintained only in the CaD group. CaD reduced PTH at 3 and 5 yr cf. controls (27.8 and 31.3%, P ≤ 0.005) in those with baseline PTH levels above the median (3.6 pmol/liter). Therapy did not affect intestinal calcium absorption at high carrier loads.

Conclusions: Addition of vitamin D to calcium has long-term beneficial effects on bone density in elderly women living in a sunny climate, probably mediated by a long-term reduction in bone turnover rate.
A homologous recombination defect affects replication-fork progression in mammalian cells
Authors: Daboussi Fayza , Courbet Sylvain , Benhamou Simone , Kannouche Patricia , Zdzienicka Malgorzata Z. , Debatisse Michelle , Lopez Bernard S.
Published: December 2007

Faithful genome transmission requires a network of pathways coordinating DNA replication to DNA repair and recombination. Here, we used molecular combing to measure the impact of homologous recombination (HR) on the velocity of DNA replication forks. We used three hamster cell lines defective in HR either by overexpression of a RAD51 dominant-negative form, or by a defect in the RAD51 paralogue XRCC2 or the breast tumor suppressor BRCA2. Irrespectively of the type or extent of HR alteration, all three cell lines exhibited a similar reduction in the rate of replication-fork progression, associated with an increase in the density of replication forks. Importantly, this phenotype was completely reversed in complemented derivatives of Xrcc2 and Brca2 mutants. These data reveal a novel role for HR, different from the reactivation of stalled replication forks, which may play an important role in genome stability and thus in tumor protection.
Neurofibromin as a regulator of melanocyte development and differentiation
Authors: Diwakar Ganesh , Zhang Deming , Jiang Shunlin , Hornyak Thomas J.
Published: December 2007

Patients with the genetic disease type I neurofibromatosis (NF1) exhibit characteristic pigmentary lesions associated with loss of a single allele of NF1, encoding the 260 kDa protein neurofibromin. To understand the basis for these pigmentary problems, the properties of melanocytes haploinsufficient for the murine gene Nf1 were studied using Nf1+/– knockout mice. We demonstrate that neurofibromin regulates the Kit-Mitf signaling axis in vivo during melanocyte development. Primary Nf1+/– melanocytes were purified by FACS to measure melanogenic gene expression. We found that Nf1+/– melanocytes exhibit higher levels of melanogenic gene expression than their wild-type counterparts. Both prior to and following Kit stimulation, Nf1+/– melanocytes also exhibit increased activation of the MAP kinase pathway compared with primary cells. The melanogenic response of primary melanocytes to Mek inhibition is consistent with the changes observed with Nf1 haploinsufficiency; however, these changes differ from those observed with their immortalized counterparts. The observation that reduction of neurofibromin, either from haploinsufficiency in the case of primary melanocytes or from neurofibromin knockdown in the case of melan-a cells, enhances melanogenic gene expression suggests that neurofibromin plays a dominant role to MEK activity in controlling melanogenic gene expression in murine melanocytes.
Core–Satellite Heterostruture of Fe3O4–Pd Nanocomposite: Selective and Magnetically Recyclable Catalyst for Decarboxylative Coupling Reaction in Aqueous Media
Authors: Yeo Kyung Min , Lee Sang Ick , Lee Young Tak , Chung Young Keun , Lee In Su
Published: December 2007

Fe3O4–Pd nanocomposite having core–satellite heterostructure, prepared through the reaction of Pluronic polymer (P123, PEO19–PPO69–PEO19)-coated Fe3O4 nanoparticle and Na2PdCl4, showed high catalytic activity, selectivity, and reusability for decarboxylative coupling reactions in aqueous media.
Note—Replenishment Sequencing in a Supply Chain with Balanced Ordering
Authors: Zhang Sheng Hao , Cheung Ki Ling
Published: December 2007

This paper studies a supply chain with one supplier and multiple heterogeneous retailers where base-stock policies are practiced. The supplier's performance, in terms of optimal cost, optimal stocking level, and implied service level, is investigated under different retailer replenishment sequences. We show that under many realistic demand distributions, it is optimal to sequence retailers according to ascending variability. Furthermore, if the retailers vary in magnitudes of their orders, then the optimal sequence is usually the one with descending magnitudes.
Lipoprotein(a) and Cardiovascular Disease in Ethnic Chinese: The Chin-Shan Community Cardiovascular Cohort Study
Authors: Chien Kuo-Liong , Hsu Hsiu-Ching , Su Ta-Chen , Sung Fung-Chang , Chen Ming-Fong , Lee Yuan-Teh
Published: December 2007

Background: Little is known about lipoprotein(a) [Lp(a)] as a predictor of vascular events among ethnic Chinese. We prospectively investigated the association of Lp(a) with cardiovascular disease and all-cause death in a community-based cohort.

Methods: We conducted a community-based prospective cohort study of 3484 participants (53% women; age range, 35–97 years) who had complete lipid measurements and were free of a cardiovascular disease history at the time of recruitment. Over a median follow-up of 13.8-years, we documented 210 cases of stroke, 122 cases of coronary heart disease (CHD), and 781 deaths.

Results: The incidences for each event increased appreciably with Lp(a) quartile for stroke and all-cause death, but not for CHD. Baseline Lp(a) concentration by quartile was not significantly associated with stroke, all-cause death, and CHD in multivariate analyses. The multivariate relative risk was significant for stroke at the 90th and 95th percentiles and for total death at the 95th and 99th percentiles.

Conclusions: Our findings suggest a threshold relationship with little gradient of risk across lower Lp(a) values for stroke and all-cause death in Chinese adults.
Influence of Pancreatic Status and Sex on Polyunsaturated Fatty Acid Profiles in Cystic Fibrosis
Authors: Coste Thierry Charles , Deumer Gladys , Reychler Gregory , Lebecque Patrick , Wallemacq Pierre , Leal Teresinha
Published: December 2007

Background: Some but not all studies have reported abnormal polyunsaturated fatty acid composition in cystic fibrosis (CF) patients. We investigated the influence of pancreatic status and sex on the fatty acid profile in plasma and erythrocyte membranes in patients with CF.

Methods: After a 1-step transesterification with acetyl chloride on plasma and washed erythrocyte membranes, we quantified fatty acid methyl esters by use of GC-MS in 124 CF patients and 80 age-matched healthy controls. In the CF group, mean (SD) age was 17.5 (11.3) years, and 51.6% were male. Pancreatic insufficiency was diagnosed in 78% of the CF population.

Results: A decrease in docosahexaenoic acid concentrations was observed in CF patients independently of pancreatic status. Pancreatic insufficient CF patients displayed lower concentrations of linoleic acid and arachidonic acid and higher concentrations of dihomo-γ-linolenic acid and eicosatrienoic acid (mead acid) in plasma and erythrocyte membranes compared with healthy controls and pancreatic sufficient CF patients. Male CF patients had significantly lower docosahexaenoic acid and higher eicosatrienoic acid in plasma and erythrocyte membranes compared with female CF patients.

Conclusions: These results support the concept that multiple abnormalities of polyunsaturated fatty acid composition participate in the CF disease phenotype and that pancreatic status plays a major role in such abnormalities. Moreover, patient sex influences the polyunsaturated fatty acid spectrum in CF, with more marked abnormalities in males.
Two-Dimensional Gas Chromatography/Electron-Impact Mass Spectrometry with Cryofocusing for Simultaneous Quantification of MDMA, MDA, HMMA, HMA, and MDEA in Human Plasma
Authors: Kolbrich Erin A , Lowe Ross H , Huestis Marilyn A
Published: December 2007

Background: 3,4-Methylenedioxymethamphetamine (MDMA, or Ecstasy) is a popular recreational drug. Analysis of MDMA and metabolites in human plasma, particularly in pharmacokinetic studies, requires low limits of quantification. Two-dimensional GC/MS with cryofocusing is a chromatographic technique recognized for its increased selectivity and resolution.

Methods: This method simultaneously quantifies 3,4-methylenedioxyethylamphetamine (MDEA), MDMA, and its metabolites, 3,4-methylenedioxyamphetamine (MDA), 4-hydroxy-3-methoxymethamphetamine (HMMA), and 4-hydroxy-3-methoxyamphetamine (HMA) in human plasma. With hydrochloric acid, we hydrolyzed 1 mL plasma, fortified with internal standard. Analytes were subjected to solid-phase extraction, derivatized with heptafluorobutyric acid anhydride, and quantified using cryofocused 2-dimensional GC/MS operated in electron-impact selected ion-monitoring mode.

Results: Limits of quantification were 1.0 μg/L for MDA and 2.5 μg/L for MDEA, MDMA, HMMA, and HMA. Calibration curves were linear to 100 μg/L for MDA and HMA and to 400 μg/L for MDEA, MDMA, and HMMA, with r2 > 0.997. At 3 concentrations spanning the linear dynamic range of the assay, mean overall extraction efficiencies from plasma were ≥85% for all compounds of interest. Recoveries were 85.6% to 107.2% of target, and intra- and interassay imprecision (CV) was <8.5% for all drugs at 3 concentrations within the range of the assay. None of the 66 exogenous compounds tested interfered with analyte quantification.

Conclusions: This GC/MS assay provides low limits of quantification for simultaneous determination of MDEA, MDMA, and metabolites MDA, HMMA, and HMA in human plasma. The 2D chromatographic system should be suitable for application to other analytes and to other complex matrices.
GABAAReceptor γ2 Subunit Mutations Linked to Human Epileptic Syndromes Differentially Affect Phasic and Tonic Inhibition
Authors: Eugène Emmanuel , Depienne Christel , Baulac Stéphanie , Baulac Michel , Fritschy Jean Marc , Le Guern Eric , Miles Richard , Poncer Jean Christophe
Published: December 2007

GABA acts on GABAAreceptors to evoke both phasic inhibitory synaptic events and persistent, tonic currents. The γ2 subunit of the GABAAreceptor is involved in both phasic and tonic signaling in the hippocampus. Several mutations of this subunit are linked to human epileptic syndromes with febrile seizures, yet it is not clear how they perturb neuronal activity. Here, we examined the expression and functional impact of recombinant γ2 in hippocampal neurons. We show that the K289M mutation has no effect on membrane trafficking and synaptic aggregation of recombinant γ2, but accelerates the decay of synaptic currents. In contrast, the R43Q mutation primarily reduces surface expression of recombinant γ2. However, it has no dominant effect on synaptic currents but instead reduces tonic GABA currents, at least in part by reducing surface expression of the α5 subunit. Our data suggests that the phenotypic specificity of mutations affecting the GABAAreceptor γ2 gene may result from different actions specific to distinct modes of GABAergic signaling.
Lim1 Is Essential for the Correct Laminar Positioning of Retinal Horizontal Cells
Authors: Poché Ross A. , Kwan Kin Ming , Raven Mary A. , Furuta Yasuhide , Reese Benjamin E. , Behringer Richard R.
Published: December 2007

Although much is known about the transcriptional regulation that coordinates retinal cell fate determination, very little is known about the developmental processes that establish the characteristic laminar architecture of the retina, in particular, the specification of neuronal positioning. The LIM class homeodomain transcription factor Lim1 (Lhx1) is expressed in postmitotic, differentiating, and mature retinal horizontal cells. We show that conditional ablation ofLim1results in the ectopic localization of horizontal cells to inner aspects of the inner nuclear layer, among the retinal amacrine cells. The ectopic cells maintain a molecular phenotype consistent with horizontal cell identity; however, these neurons adopt a unique morphology more reminiscent of amacrine cells, including a dendritic arbor positioned within the inner plexiform layer. All other retinal cell populations appear unaltered. Our data suggest a model wherebyLim1lies downstream of horizontal cell fate determination factors and functions cell autonomously to instruct differentiating horizontal cells to the appropriate laminar position in the developing retina. This study is the first to describe a cell type-specific genetic program that is essential for targeting a discrete retinal neuron population to the proper lamina.
Repeated Electrical Stimulation of Reward-Related Brain Regions Affects Cocaine But Not “Natural” Reinforcement
Authors: Levy Dino , Shabat-Simon Maytal , Shalev Uri , Barnea-Ygael Noam , Cooper Ayelet , Zangen Abraham
Published: December 2007

Drug addiction is associated with long-lasting neuronal adaptations including alterations in dopamine and glutamate receptors in the brain reward system. Treatment strategies for cocaine addiction and especially the prevention of craving and relapse are limited, and their effectiveness is still questionable. We hypothesized that repeated stimulation of the brain reward system can induce localized neuronal adaptations that may either potentiate or reduce addictive behaviors. The present study was designed to test how repeated interference with the brain reward system using localized electrical stimulation of the medial forebrain bundle at the lateral hypothalamus (LH) or the prefrontal cortex (PFC) affects cocaine addiction-associated behaviors and some of the neuronal adaptations induced by repeated exposure to cocaine. Repeated high-frequency stimulation in either site influenced cocaine, but not sucrose reward-related behaviors. Stimulation of the LH reduced cue-induced seeking behavior, whereas stimulation of the PFC reduced both cocaine-seeking behavior and the motivation for its consumption. The behavioral findings were accompanied by glutamate receptor subtype alterations in the nucleus accumbens and the ventral tegmental area, both key structures of the reward system. It is therefore suggested that repeated electrical stimulation of the PFC can become a novel strategy for treating addiction.
Diversity in the Neural Circuitry of Cold Sensing Revealed by Genetic Axonal Labeling of Transient Receptor Potential Melastatin 8 Neurons
Authors: Takashima Yoshio , Daniels Richard L. , Knowlton Wendy , Teng James , Liman Emily R. , McKemy David D.
Published: December 2007

Sensory nerves detect an extensive array of somatosensory stimuli, including environmental temperatures. Despite activating only a small cohort of sensory neurons, cold temperatures generate a variety of distinct sensations that range from pleasantly cool to painfully aching, prickling, and burning. Psychophysical and functional data show that cold responses are mediated by both C- and Aδ-fibers with separate peripheral receptive zones, each of which likely provides one or more of these distinct cold sensations. With this diversity in the neural basis for cold, it is remarkable that the majority of cold responsesin vivoare dependent on the cold and menthol receptor transient receptor potential melastatin 8 (TRPM8). TRPM8-null mice are deficient in temperature discrimination, detection of noxious cold temperatures, injury-evoked hypersensitivity to cold, and nocifensive responses to cooling compounds. To determine how TRPM8 plays such a critical yet diverse role in cold signaling, we generated mice expressing a genetically encoded axonal tracer in TRPM8 neurons. Based on tracer expression, we show that TRPM8 neurons bear the neurochemical hallmarks of both C- and Aδ-fibers, and presumptive nociceptors and non-nociceptors. More strikingly, TRPM8 axons diffusely innervate the skin and oral cavity, terminating in peripheral zones that contain nerve endings mediating distinct perceptions of innocuous cool, noxious cold, and first- and second-cold pain. These results further demonstrate that the peripheral neural circuitry of cold sensing is cellularly and anatomically complex, yet suggests that cold fibers, caused by the diverse neuronal context of TRPM8 expression, use a single molecular sensor to convey a wide range of cold sensations.
Impact of body mass index on blood pressure levels in patients with polycystic ovary syndrome
Authors: Barcellos Cristiano R.G. , Rocha Michelle P. , Hayashida Sylvia A.Y. , Mion Junior Décio , Lage Silvia G. , Marcondes José A.M.
Published: December 2007

As there is controversy about the prevalence of hypertension in patients with polycystic ovary syndrome (PCOS) and, up to the present moment, no studies have evaluated the impact of body mass index (BMI) on blood pressure levels (BP) in these patients, we studied retrospectively sixty-nine patients with PCOS, with BMI of 29.0 ± 6.7 kg/m² and aged 25.6 ± 5.6 yr, subdivided into three groups according to BMI (normal, overweight and obese) and evaluated regarding BP (mercury sphygmomanometer), basal hormonal profile, fasting glucose, and insulin sensitivity (HOMA-IR). Mean systolic blood pressure (SBP) and diastolic blood pressure (DBP) were normal (118.1 ± 17.0 and 74.7 ± 11.5 mmHg, respectively), with a hypertension prevalence of 20.3%. Of these patients, 78.6% were obese and 21.4% were overweight. When the groups were compared according to BMI, a significant increase in SBP and DBP was observed (higher in overweight and obese patients for SBP and higher in obese for DBP), as well as a significant progressive increase in glucose, insulin, homeostatic model assessment, and a significant progressive decline in LH levels. When the patients were subdivided as normotensive or hypertensive, a significant difference was observed only for BMI (28.2 ± 6.1 and 34.7 ± 8.6 kg/m², respectively; p = 0.007). In conclusion, we observed a significant and progressive impact of BMI on blood pressure levels in our patients with polycystic ovary syndrome.
Estudo de materiais calcários usados como corretivos do solo no estado de São Paulo. IV - O poder relativo de neutralização total
Authors: Van Raij Bernardo
Published: December 2007

São apresentados dados do poder relativo de neutralização total (PRNT) de calcários utilizados como corretivos do solo no Estado de São Paulo. O PRNT é uma medida da eficiência dos calcários que conjuga o poder de neutralização total com a eficiência relativa de partículas de diferentes tamanhos. No trabalho é proposto o cálculo do PRNT com utilização dos teores de cálcio e magnésio e a distribuição granulométrica determinada apenas com as peneiras 10 e 50. Os resultados de PRNT das 25 amostras de calcários analisadas variaram de 52,3 a 93,8% de CaCO3 equivalente, com um valor médio de 66,9%.
Composição mineral de frutos tropicais na colheita
Authors: Hiroce Rúter , Carvalho A. M. De , Bataglia Ondino C. , Furlani Pedro R. , Furlani Ângela Maria C. , Santos Rui R. dos , Açu E. E. de Pariquera , Gallo J. Romano
Published: December 2007

Amostras de diversas partes de frutos tropicais foram colhidas para estudo de sua composição mineral. Os materiais estudados foram representados por amostras de abacate "collinson", abacaxi "cayenne", banana "nanicão", castanha-do-pará, goiaba "IAC-4", jaca-dura, mamão-de-polpa-amarela, mangas "haden", "extrema" e "carlota", e maracujá flavicarpa. Para as análises químicas, os frutos foram divididos em casca, polpa e sementes (abacate e jaca); em casca + polpa e sementes (mamão e manga); em casca e polpa (abacaxi); em casca do fruto, casca de amêndoa e amêndoa (castanha-do-pará); banana, goiaba e maracujá não foram divididos. Foram calculadas as porcentagens de água nessas partes e as proporções dessas partes em relação ao fruto inteiro. Nas amostras secas dos frutos ou de suas partes foram dosados todos os nutrientes minerais das plantas, além de cobalto, alumínio e sódio. As quantidades dos elementos extraídos foram calculadas por tonelada de frutos nas condições normais de colheita. De um modo geral, nitrogênio e potássio foram os nutrientes extraídos em quantidades mais elevadas e o molibdênio, nas mais baixas. A castanha-do-pará foi o fruto que extraiu os nutrientes em quantidades mais elevadas.
Oito ciclos de seleção entre e dentro de famílias de meios irmãos no milho IAC-1
Authors: Miranda Luiz Torres de , Miranda Luiz Eugênio Coelho de , Pommer Celso Valdevino , Sawazaki Eduardo
Published: December 2007

São relatados os resultados obtidos em oito ciclos de seleção entre e dentro de famílias de meios irmãos numa população de milho, o IAC-1. Para produção de grãos foi observado um progresso genético médio de 1,9% por ciclo, comparado com um progresso genético esperado de 8,8% por ciclo. Para índice-de-espigas foi estimado um progresso genético esperado de 1,5% por ciclo aplicando-se os mesmos diferenciais de seleção utilizados para produção. Entretanto, não foi feita seleção sistemática entre progênies para este caráter. A porcentagem de plantas acamadas e quebradas não se alterou profundamente no decorrer dos ciclos de seleção. Houve um melhoramento real na população.
Resistência do cafeeiro a nematóides: I - Testes em progênies e híbridos, para Meloidogyne exigua
Authors: Fazuoli L. C. , Mônaco L. C. , Carvalho A. , Reis A. J.
Published: December 2007

Procurou-se identificar fontes de resistência ao nematóide Meloidogyne exígua em cafeeiros derivados de híbridos interespecíficos e em progênies de café arábica oriundas da Etiópia, em experimentos estabelecidos em duas localidades. A infestação foi feita por dois processos usados com freqüência nesse tipo de trabalho. As avaliações do grau de ataque foram feitas quatro e 12 meses após a infestação, em Campinas e Ribeirão Preto, respectivamente, adotando-se escala variando de zero, para ausência de galhas, a cinco pontos para grande intensidade de ataque. Verificou-se que a leitura feita aos quatro meses é tão eficiente quanto aos 12 meses, indicando a possibilidade de abreviar consideravelmente a duração dessas avaliações. Notou-se, no experimento de Ribeirão Preto, uma redução de aproximadamente 8% no crescimento das mudas infestadas e verificou-se, também, uma redução de 11,5% e 12% nos pesos verde e seco das plantas, devido ao ataque do nematóide. De 1.692 plantas examinadas nos dois experimentos, selecionaram-se 106 (6,3%), caracterizadas pela ausência de galhas. As populações derivadas dos híbridos entre Coffea arabica e C. canephora revelaram-se mais promissoras, contribuindo com maior número de plantas resistentes. As plantas do experimento instalado em Campinas foram inoculadas também com a raça II de Hemileia vastatrix para o estudo da resistência conjunta aos dois patógenos. Essas seleções, em número de 38, representam valioso material para o programa de melhoramento do cafeeiro.
Efeito da seleção para produção e qualidade protéica no grau de dano da lagarta-da-espiga, Heliothis zea em populações de milho opaco
Authors: Rezende Jorge A. M. , Pommer Celso V.
Published: December 2007

Estudou-se o comportamento das populações de milho opaco-2 IAC Maya o2. IAC-1 o2, do seu híbrido intervarietal IAC Phoenyx o2 e do híbrido comercial IAC Hmd 7974, em relação ao ataque da lagarta-da-espiga, Heliothis zea (Boddie, 1850) (Lepidoptera, Noctuidae). Nesses milhos, nenhuma seleção dirigida foi praticada para resistência à lagarta-da-espiga ou a qualquer outra espécie de praga. Os resultados obtidos indicaram uma resposta quadrática dos ciclos de seleção da população IAC Maya o2 ao dano de H. zea, enquanto para a população IAC-1 o2 foi obtido um progresso genético de 3.39% por ciclo em relação à média, sendo que a nota de dano do ciclo 4 foi 13,6% menor que a do ciclo original. O híbrido intervarietal IAC Phoenyx o2 mostrou danos semelhantes de H. zea em todos os ciclos. O híbrido duplo comercial IAC Hmd 7974 foi o mais danificado pela lagarta-da-espiga, nos quatro locais observados.
"Delineamento duplo central composto com 29 pontos"
Authors: Conagin Armando , Jorge Joassy de Paula Neves
Published: December 2007

O delineamento duplo central composto com 29 pontos representa uma extensão do delineamento central composto e foi desenvolvido para o estudo de três fatores em mais de três níveis. Essencialmente, consta de dois fatoriais 2³ (níveis 1 e B), de duas estrelas (níveis a e 2alfa) e de um ponto no centro do delineamento. É mostrada a origem do delineamento, o tipo não ortogonal, completamente casualizado, o tipo ortogonal completamente casualizado e o ortogonal divisível em dois blocos. No primeiro deles, seriam estudados três fatores em cinco níveis (-2, -1,-0, + 1 e +2); no segundo, três fatores em nove níveis (-3,02; -2,00; -1,51; -1,00; 0,00; + 1,00; +1,51; +2,00 e +3.02) e, no terceiro, três fatores nos nove níveis seguintes (-7,262; -4,391; -3,631; -1,000; 0,000; +1,000; +3,631; +4,391 e +7,262). É apresentado também um exemplo do último delineamento. com sua análise respectiva. De acordo com o critério de Box & Wilson (2), esse último delineamento é mais eficiente que o fatorial 3 x 3 x 3 divisível em blocos de nove. Os três delineamentos podem ser empregados em programas de adubação visando ao estudo de macronutrientes com vistas à recomendação das doses ótimas de fertilizantes que possibilitem a maximização do lucro obtido e, ainda, em outras áreas da pesquisa científica em que se deseja a avaliação da superfície de resposta, o estudo dos seus pontos extremos, etc.
Delineamentos "compostos centrais ortogonais, rotacionais e divisíveis em blocos"
Authors: Conagin Armando
Published: December 2007

Na família dos delineamentos compostos centrais, os compostos centrais ortogonais são mais eficientes que os outros e a estimação dos coeficientes do modelo é facilmente obtida. Dentro da família dos delineamentos compostos centrais ortogonais, os compostos centrais ortogonais rotacionais apresentam algumas vantagens adicionais, principalmente uma uniformidade de variâncias para os pontos que se encontram à mesma distância do centro do delineamento. A obtenção das propriedades ortogonalidade, rotacionalidade e partição em blocos torna o delineamento mais eficiente e aplicável naqueles casos em que possam existir gradientes como o de fertilidade, no caso da experimentação de campo. A partição em dois, três ou cinco blocos é, então, altamente desejável. Delineamentos com essas três características foram conseguidos para determinadas combinações de valores, sendo os resultados mais interessantes apresentados no quadro 1 para k = 2, 3, 4, 5, 6 e 7; os resultados que apresentam um asterisco representam delineamentos ortogonais, quase rotacionais e subdivisíveis em blocos, de forma quase perfeitamente ortogonal (as covariancias entre os coeficientes quadráticos puros e os coeficientes de blocos são quase nulas); para fins práticos, esses delineamentos poderiam ser tratados como se fossem ortogonalmente subdivididos em blocos. As soluções obtidas implicam a exigência de ser alocado certo número de pontos centrais; esses pontos, por sua vez, possibilitam uma estimativa precisa do erro e o teste de adequação do modelo.
Alumínio trocável e saturação em bases como critérios para recomendação de calagem
Authors: Van Raij Bernardo , Camargo Antonio Pereira de , Cantarella Heitor , Silva Nelson Machado da
Published: December 2007

O critério do alumínio para determinar a necessidade de calagem de solos, vem sendo usado há dezesseis anos no Brasil. As quantidades de calcário indicadas são em geral baixas. Neste trabalho, procurou-se avaliar esse método, com base em resultados de ensaios de calagem, realizados em três locais e durante vários anos. Em Mococa, em podzólico vermelho-amarelo, foram considerados cinco plantios de milho, um de algodão e um de soja; em São Simão, em latossolo vermelho-escuro textura média, três plantios de soja; em Guaíra, em latossolo roxo, três plantios de algodão. Em todos os casos, a produção continuava a aumentar, com a elevação das doses de calcário, mesmo em níveis de calagem superiores àqueles suficientes para praticamente neutralizar o alumínio. Mostrou-se que o critério do alumínio não é adequado, do ponto de vista quantitativo, para cálculos de calagem. O critério da saturação em bases apresentou-se como alternativa adequada, para esse fim, relacionando bem com as respostas das culturas, além de ser muito flexível, de fácil utilização, e apresentar fundamento teórico adequado. Em geral, a produção máxima não foi atingida nos ensaios, mas estimou-se que ela seria obtida com valores de saturação em bases acima de 60%.
Qualidade do fio "open-end" obtido com matérias-primas produzidas por variedades paulistas de algodoeiro e suas misturas com poliéster
Authors: Kondo Julio Isao , Sabino Nelson Paulieri , Fuzatto Milton Geraldo , Campanatti Gilberto
Published: December 2007

No presente trabalho, foi avaliada a pontencialidade de duas variedades paulistas de algodoeiro, atualmente em distribuição para plantio no Estado, e o efeito da mistura da sua matéria-prima com fibras sintéticas, representadas pelo poliéster, com respeito às principais características do fio obtido através do novo processo conhecido como "open-end". O algodão utilizado no estudo, proveniente das variedades IAC 17 e IAC 18, foi colhido nas Estações Experimentais do Instituto Agronômico, localizadas em Tietê e Tatuí respectivamente, no ano agrícola de 1978/79. A variedade IAC 18 proporcionou a obtenção de fios "open-end" de melhor qualidade, quando comparada a IAC 17, embora as diferenças nas características do fio produzido não tenham sido tão marcantes quanto aquelas encontradas nas propriedades físicas da fibra. A mistura de poliéster ao algodão serviu para melhorar as características dos fios produzidos, principalmente com relação a tenacidade. As indústrias de fiação que utilizam esse processo poderão ter uma previsão de qualidade dos fios a serem produzidos com algodões das variedades estudadas, ou com suas misturas com poliéster, através das equações de regressão apresentadas.
Tolerância de cultivares de arroz a dois níveis de alumínio em soluções nutritivas contendo diferentes concentrações de sais
Authors: Camargo Carlos Eduardo de Oliveira
Published: December 2007

Foi estudado o comportamento diferencial de seis cultivares de arroz em soluções nutritivas contendo dois níveis de alumínio (20 e 40mg/litro) combinados com quatro diferentes concentrações salinas. A tolerância ao excesso de Al foi medida pelo comprimento médio das raízes e pelo peso da matéria seca da parte aérea dos cultivares avaliados após dez dias de crescimento em solução nutritiva contendo uma concentração calculada de sais e de alumínio. Os cultivares IAC-120, IAC-435, IAC-164 e IAC-165 foram tolerantes a 20mg/litro de Al3+, independente da concentração salina das soluções, e IAC-899 e IR-841 foram sensíveis a essa concentração de alumínio quando a concentração salina foi diluída para um quinto e um décimo da solução nutritiva completa. Os cultivares IAC-120, IAC-435, IAC-164 e IAC-165 foram mais tolerantes a 40mg/litro de Al3+ quando se empregaram soluções salinas mais concentradas, mostrando, porém, menor tolerância a essa concentração de Al3+ nas soluções salinas com um décimo da concentração da nutritiva completa. Os cultivares IAC-899 e IR-841 foram sensíveis a 40mg/litro de Al3+, mesmo com soluções salinas mais concentradas, e aumentaram essa sensibilidade à medida que as concentrações salinas das soluções se tornaram mais diluídas. Os sintomas de toxicidade de alumínio em arroz poderiam ser obtidos ou por aumentar a concentração de alumínio ou por diminuir as concentrações de sais da solução nutritiva para todos os cultivares estudados, mantendo-se constante a temperatura de 30±1°C e o pH 4,0.
Efeito de diferentes condições de fermentação sobre o teor e composição da fração de sapogeninas do suco de sisal
Authors: Zullo Marco Antonio Teixeira , Moraes Roberto Machado de , Salgado Antonio Luiz de Barros , Azzini Anísio
Published: December 2007

Suco de sisal (Agave sisalana (Engelm.) Perrine), recém-colhido, foi deixado fermentar por dez dias, espontaneamente ou por Saccharomyces cerevisae, processando-se, em cada caso, a fermentação protegida ou não do ambiente. Observou-se que os teores de sapogeninas totais, hecogenina, tigogenina, de duas sapogeninas não-identificadas, e de sólidos totais são significativamente dependentes do tipo e da duração da fermentação, sendo a última característica dependente também da condição de fermentação. Obtiveram-se maiores teores de sólidos totais e de sapogeninas totais por fermentação espontânea que por S. cerevisae e, em ambos os casos, quando protegida do ambiente. Não há, entretanto, qualquer correlação significativa entre os teores de sólidos totais e de sapogeninas. As reações de formação de sapogeninas são oscilantes, fazendo que os maiores teores de sapogeninas sejam obtidos em torno do segundo dia de fermentação.
Deslignificação dos resíduos agrícolas da cultura da mamona para produção de celulose e papel
Authors: Azzini Anísio , Savy Filho Ângelo , Salgado Antonio Luiz de Barros , Arnaldi Francisca Zuleide
Published: December 2007

Foram estudados os resíduos agrícolas da cultura da mamona (cultivar IAC-80), visando a sua conversão em celulose para papel, mediante os processos alcalinos soda e sulfato. A quantidade estimada desse material nas áreas dos experimentos foi 17, 20 e 26t/ha, respectivamente, para as regiões de Campinas, Tatuí e Tietê. A densidade básica dos caules e ramos da mamona em comparação com as madeiras é baixa (0,228g/cm³). O estudo micrométrico mostrou que as fibras do líber são extremamente longas (5,51mm), contrastando com as fibras curtas do lenho (0,87mm). Os valores obtidos para as diversas características tecnológicas estudadas evidenciam a possibilidade técnica de utilizar esse resíduo agrícola para produção de celulose e papel, ressaltando que seu principal inconveniente é o elevado teor de medula (21,17%). A fração medular, por não ser fibrosa, influi negativamente no rendimento em celulose e no consumo de reagentes químicos.