bluuebunny/crossref_metadata_2025 huggingface dataset:
A soluble form of ammonia monooxygenase in Nitrosomonas europaea
Authors: Gilch Stefan , Meyer Ortwin , Schmidt Ingo
Published: May 2009

Ammonia monooxygenase (AMO) of Nitrosomonas europaea is a metalloenzyme that catalyzes the oxidation of ammonia to hydroxylamine. This study shows that AMO resides in the cytoplasm of the bacteria in addition to its location in the membrane and is distributed approximately equally in both subcellular fractions. AMO in both fractions catalyzes the oxidation of ammonia and binds [14C]acetylene, a mechanism-based inhibitor which specifically interacts with catalytically active AMO. Soluble AMO was purified 12-fold to electrophoretic homogeneity with a yield of 8%. AMO has a molecular mass of approximately 283 kDa with subunits of ca. 27 kDa (α-subunit, AmoA), ca. 42 kDa (β-subunit, AmoB), and ca. 24 kDa (γ-subunit, cytochrome c
1) in an α3β3γ3 sub-unit structure. Different from the β-subunit of membrane-bound AMO, AmoB of soluble AMO possesses an N-terminal signal sequence. AMO contains Cu (9.4±0.6 mol per mol AMO), Fe (3.9±0.3 mol per mol AMO), and Zn (0.5 to 2.6 mol per mol AMO). Upon reduction the visible absorption spectrum of AMO reveals absorption bands characteristic of cytochrome c. Electron para-magnetic resonance spectroscopy of air-oxidized AMO at 50 K shows a paramagnetic signal originating from Cu2+ and at 10 K a paramagnetic signal characteristic of heme-Fe.
Emerging roles of mitochondrial membrane dynamics in health and disease
Authors: Schäfer Anja , Reichert Andreas S.
Published: May 2009

Mitochondria are highly dynamic organelles forming a tubular network that is sustained by fusion and fission events. Impairment thereof leads to various neuropathies in humans, such as optic atrophy and Parkinson's disease. We have only begun to understand the molecular machineries facilitating fusion and fission of mitochondria and how these processes are regulated. The physiological role of mitochondrial dynamics and how it may be involved in maintaining mitochondrial functionality is still unclear. Here, we discuss current views in this emerging field focusing on the molecular basis of how mitochondrial morphology is regulated and how this may contribute to mitochondrial quality control.
Multiple pathways for mitochondrial protein traffic
Authors: Endo Toshiya , Yamano Koji
Published: May 2009

Mitochondria are two-membrane bounded organelles consisting of 1000–2000 different proteins, most of which are synthesized in the cytosol and subsequently imported into mitochondria. The imported proteins are further sorted to one of the four compartments, the outer membrane, intermembrane space, inner membrane, and matrix, mostly following one of the five major pathways. Mitochondrial protein import and sorting are mediated by the translocator complexes in the membranes and chaperones in the aqueous compartments operating along the import pathways. Here, we summarize the expanding knowledge on the roles of translocators, chaperones, and related components in the multiple pathways for mitochondrial protein trafficking.
The nanodisc: a novel tool for membrane protein studies
Authors: Borch Jonas , Hamann Thomas
Published: May 2009

A major challenge in the research on membrane-anchored and integral membrane protein complexes is to obtain these in a functionally active, water-soluble, and monodisperse form. This requires the incorporation of the membrane proteins into a native-like membrane or detergent micelle that mimics the properties of the original biological membrane. However, solubilization in detergents or reconstitution in liposomes or supported monolayers sometimes suffers from loss of activity and problematic analyses due to heterogeneity and aggregation. A developing technology termed nanodiscs exploits discoidal phospholipid bilayers encircled by a stabilizing amphipatic helical membrane scaffold protein to reconstitute membranes with integral proteins. After reconstitution, the membrane nanodisc is soluble, stable, and monodisperse. In the present review, we outline the biological inspiration for nanodiscs as discoidal high-density lipoproteins, the assembly and handling of nanodiscs, and finally their diverse biochemical applications. In our view, major advantages of nanodisc technology for integral membrane proteins is homogeneity, control of oligomerization state, access to both sides of the membrane, and control of lipids in the local membrane environment of the integral protein.
Mobilization of Calcium from Intracellular Stores Facilitates Somatodendritic Dopamine Release
Authors: Patel Jyoti C. , Witkovsky Paul , Avshalumov Marat V. , Rice Margaret E.
Published: May 2009

Somatodendritic dopamine (DA) release in the substantia nigra pars compacta (SNc) shows a limited dependence on extracellular calcium concentration ([Ca2+]o), suggesting the involvement of intracellular Ca2+stores. Here, using immunocytochemistry we demonstrate the presence of the sarcoplasmic/endoplasmic reticulum Ca2+-ATPase 2 (SERCA2) that sequesters cytosolic Ca2+into the endoplasmic reticulum (ER), as well as inositol 1,4,5-triphosphate receptors (IP3Rs) and ryanodine receptors (RyRs) in DAergic neurons. Notably, RyRs were clustered at the plasma membrane, poised for activation by Ca2+entry. Using fast-scan cyclic voltammetry to monitor evoked extracellular DA concentration ([DA]o) in midbrain slices, we found that SERCA inhibition by cyclopiazonic acid (CPA) decreased evoked [DA]oin the SNc, indicating a functional role for ER Ca2+stores in somatodendritic DA release. Implicating IP3R-dependent stores, an IP3R antagonist, 2-APB, also decreased evoked [DA]o. Moreover, DHPG, an agonist of group I metabotropic glutamate receptors (mGluR1s, which couple to IP3production), increased somatodendritic DA release, whereas CPCCOEt, an mGluR1 antagonist, suppressed it. Release suppression by mGluR1 blockade was prevented by 2-APB or CPA, indicating facilitation of DA release by endogenous glutamate acting via mGluR1s and IP3R-gated Ca2+stores. Similarly, activation of RyRs by caffeine increased [Ca2+]iand elevated evoked [DA]o. The increase in DA release was prevented by a RyR blocker, dantrolene, and by CPA. Importantly, the efficacy of dantrolene was enhanced in low [Ca2+]o, suggesting a mechanism for maintenance of somatodendritic DA release with limited Ca2+entry. Thus, both mGluR1-linked IP3R- and RyR-dependent ER Ca2+stores facilitate somatodendritic DA release in the SNc.
Interruption of β-Catenin Signaling Reduces Neurogenesis in Alzheimer's Disease
Authors: He Ping , Shen Yong
Published: May 2009

The neuronal loss associated with Alzheimer's disease (AD) affects areas of the brain that are vital to cognition. Although recent studies have shown that new neurons can be generated from progenitor cells in the neocortices of healthy adults, the neurogenic potential of the stem/progenitor cells of AD patients is not known. To answer this question, we compared the properties of glial progenitor cells (GPCs) from the cortices of healthy control (HC) and AD subjects. The GPCs from AD brain samples displayed reduced renewal capability and reduced neurogenesis compared with GPCs from HC brains. To investigate the mechanisms underlying this difference, we compared β-catenin signaling proteins in GPCs from AD versus HC subjects and studied the effect of amyloid β peptide (Aβ, a hallmark of AD pathology) on GPCs. Interestingly, GPCs from AD patients exhibited elevated levels of glycogen synthase kinase 3β (GSK-3β, an enzyme known to phosphorylate β-catenin), accompanied by an increase in phosphorylated β-catenin and a decrease in nonphosphorylated β-catenin compared with HC counterparts. Furthermore. we found that Aβ treatment impaired the ability of GPCs from HC subjects to generate new neurons and caused changes in β-catenin signaling proteins similar to those observed in GPCs from AD patients. Similar results were observed in GPCs isolated from AD transgenic mice. These results suggest that Aβ-induced interruption of β-catenin signaling may contribute to the impairment of neurogenesis in AD progenitor cells.
p53-Dependent Transcriptional Control of Cellular Prion by Presenilins
Authors: Vincent Bruno , Sunyach Claire , Orzechowski Hans-Dieter , St George-Hyslop Peter , Checler Frédéric
Published: May 2009

The presenilin-dependent γ-secretase processing of the β-amyloid precursor protein (βAPP) conditions the length of the amyloid β peptides (Aβ) that accumulate in the senile plaques of Alzheimer's disease-affected brains. This, together with an additional presenilin-mediated ε-secretase cleavage, generates intracellular βAPP-derived fragments named amyloid intracellular domains (AICDs) that regulate the transcription of several genes. We establish that presenilins control the transcription of cellular prion protein (PrPc) by a γ-secretase inhibitor-sensitive and AICD-mediated process. We demonstrate that AICD-dependent control of PrPcinvolves the tumor suppressor p53. Thus, p53-deficiency abolishes the AICD-mediated control of PrPctranscription. Furthermore, we show that p53 directly binds to the PrPcpromoter and increases its transactivation. Overall, our study unravels a transcriptional regulation of PrPcby the oncogene p53 that is directly driven by presenilin-dependent formation of AICD. Furthermore, it adds support to previous reports linking secretase activities involved in βAPP metabolism to the physiology of PrPc.
Anterior Cingulate Neurons Represent Errors and Preparatory Attention within the Same Behavioral Sequence
Authors: Totah Nelson K. B. , Kim Yun Bok , Homayoun Houman , Moghaddam Bita
Published: May 2009

The anterior cingulate cortex (ACC) has been implicated in both preparatory attention (i.e., selecting behaviorally relevant stimuli) and in detecting errors. We recorded from the rat ACC and medial prefrontal cortex (mPFC), which is functionally homologous to the primate dorsolateral PFC, during an attention task. The three-choice serial reaction time task requires a rat to orient toward and divide attention between three brief (300 ms duration) light stimuli presented in random order across nose poke holes in an operant chamber. In both the ACC and mPFC, we found that neural activity was related to the level of preparatory (precue) attention and subsequent correct or incorrect choice, in that the magnitude of the single units' response to the cue was lower on incorrect trials and was not different than baseline on unattended trials. This preparatory neural activity consisted of both excitatory and inhibitory phasic responses. The number of units responding to the cue was similarly graded, in that fewer units exhibited phasic responses to the cue on incorrect and unattended trials, compared with correct trials. Although preparatory activity was found in both the ACC and mPFC, activity after incorrect nose pokes, which may be related to error detection, were only observed in the ACC. Thus, during the same behavioral sequence, the ACC encodes both error-related events and preparatory attention, whereas the mPFC only participates in preparatory attention. The finding of substantial inhibitory activity during the preparatory period suggests a critical role for inhibition of pyramidal cells in PFC-mediated cognitive functions.
A Role for Medial Prefrontal Dopaminergic Innervation in Instrumental Conditioning
Authors: Naneix Fabien , Marchand Alain R. , Scala Georges Di , Pape Jean-Rémi , Coutureau Etienne
Published: May 2009

To investigate the involvement of dopaminergic projections to the prelimbic and infralimbic cortex in the control of goal-directed responses, a first experiment examined the effect of pretraining 6-OHDA lesions of these cortices. We used outcome devaluation and contingency degradation procedures to separately assess the representation of the outcome as a goal or the encoding of the contingency between the action and its outcome. All groups acquired the instrumental response at a normal rate, indicating that dopaminergic activity in the medial prefrontal cortex is not necessary for the acquisition of instrumental learning. Sham-operated animals showed sensitivity to both outcome devaluation and contingency degradation. Animals with dopaminergic lesions of the prelimbic cortex, but not the infralimbic cortex, failed to adapt their instrumental response to changes in contingency, whereas their response remained sensitive to outcome devaluation. In a second experiment, aimed at determining whether dopamine was specifically needed during contingency changes, we performed microinfusions of the dopamine D1/D2receptor antagonist flupenthixol in the prelimbic cortex only before contingency degradation sessions. Animals with infusions of flupenthixol failed to adapt their response to changes in contingency, thus replicating the deficit of animals with dopaminergic lesions in Experiment 1. These results demonstrate that dissociable neurobiological mechanisms support action–outcome relationships and goal representation, dopamine signaling in the prelimbic cortex being necessary for the former but not the latter.
Learning Optimal Adaptation Strategies in Unpredictable Motor Tasks
Authors: Braun Daniel A. , Aertsen Ad , Wolpert Daniel M. , Mehring Carsten
Published: May 2009

Picking up an empty milk carton that we believe to be full is a familiar example of adaptive control, because the adaptation process of estimating the carton's weight must proceed simultaneously with the control process of moving the carton to a desired location. Here we show that the motor system initially generates highly variable behavior in such unpredictable tasks but eventually converges to stereotyped patterns of adaptive responses predicted by a simple optimality principle. These results suggest that adaptation can become specifically tuned to identify task-specific parameters in an optimal manner.
Lewisxand α2,3-Sialyl Glycans and Their Receptors TAG-1, Contactin, and L1 Mediate CD24-Dependent Neurite Outgrowth
Authors: Lieberoth Annika , Splittstoesser Frauke , Katagihallimath Nainesh , Jakovcevski Igor , Loers Gabriele , Ranscht Barbara , Karagogeos Domna , Schachner Melitta , Kleene Ralf
Published: May 2009

Although carbohydrates have been implicated in cell interactions in the nervous system, the molecular bases of their functions have remained largely obscure. Here, we show that promotion or inhibition of neurite outgrowth of cerebellar or dorsal root ganglion neurons, respectively, induced by the mucin-type adhesion molecule CD24 depends on α2,3-linked sialic acid and Lewisxpresent on glia-specific CD24 glycoforms. α2,3-Sialyl residues of CD24 bind to a structural motif in the first fibronectin type III domain of the adhesion molecule L1. Following the observation that the adhesion molecules TAG-1 and Contactin show sequence homologies with fucose-specific lectins, we obtained evidence that TAG-1 and Contactin mediate Lewisx-dependent CD24-induced effects on neurite outgrowth. Thus, L1, TAG-1, and Contactin function as lectin-like neuronal receptors. Theircisinteractions with neighboring adhesion molecules, e.g., Caspr1 and Caspr2, and with their triggered signal transduction pathways elicit cell type-specific promotion or inhibition of neurite outgrowth induced by glial CD24 in a glycan-dependenttransinteraction.
Postinjury Niches Induce Temporal Shifts in Progenitor Fates to Direct Lesion Repair after Spinal Cord Injury
Authors: Sellers Drew L. , Maris Don O. , Horner Philip J.
Published: May 2009

Progenitors that express NG2-proteoglycan are the predominant self-renewing cells within the CNS. NG2 progenitors replenish oligodendrocyte populations within the intact stem cell niche, and cycling NG2 cells are among the first cells to react to CNS insults. We investigated the role of NG2 progenitors after spinal cord injury and how bone morphogen protein signals remodel the progressive postinjury (PI) niche. Progeny labeled by an NG2-specific reporter virus undergo a coordinated shift in differentiation profile. NG2 progeny born 24 h PI produce scar-forming astrocytes and transient populations of novel phagocytic astrocytes shown to contain denatured myelin within cathepsin-D-labeled endosomes, but NG2 progenitors born 7 d PI differentiate into oligodendrocytes and express myelin on processes that wrap axons. Analysis of spinal cord mRNA shows a temporal shift in the niche transcriptome of ligands that affect PI remodeling and direct progenitor differentiation. We conclude that NG2 progeny are diverse lineages that obey progressive cues after trauma to replenish the injured niche.
Mitochondrial Cholesterol Loading Exacerbates Amyloid β Peptide-Induced Inflammation and Neurotoxicity
Authors: Fernández Anna , Llacuna Laura , Fernández-Checa José C. , Colell Anna
Published: May 2009

The role of cholesterol in Alzheimer's disease (AD) has been linked to the generation of toxic amyloid β peptides (Aβ). Using genetic mouse models of cholesterol loading, we examined whether mitochondrial cholesterol regulates Aβ neurotoxicity and AD pathology. Isolated mitochondria from brain or cortical neurons of transgenic mice overexpressing SREBP-2 (sterol regulatory element binding protein 2) or NPC1 (Niemann-Pick type C1) knock-out mice exhibited mitochondrial cholesterol accumulation, mitochondrial glutathione (mGSH) depletion and increased susceptibility to Aβ1–42-induced oxidative stress and release of apoptogenic proteins. Similar findings were observed in pharmacologically GSH-restricted rat brain mitochondria, while selective mGSH depletion sensitized human neuronal and glial cell lines to Aβ1–42-mediated cell death. Intracerebroventricular human Aβ delivery colocalized with mitochondria resulting in oxidative stress, neuroinflammation and neuronal damage that were enhanced in Tg-SREBP-2 mice and prevented upon mGSH recovery by GSH ethyl ester coinfusion, with a similar protection observed by intraperitoneal administration of GSH ethyl ester. Finally, APP/PS1 (amyloid precursor protein/presenilin 1) mice, a transgenic AD mouse model, exhibited mitochondrial cholesterol loading and mGSH depletion. Thus, mitochondrial cholesterol accumulation emerges as a novel pathogenic factor in AD by modulating Aβ toxicity via mGSH regulation; strategies boosting the particular pool of mGSH may be of relevance to slow down disease progression.
Context-Specific Grasp Movement Representation in the Macaque Anterior Intraparietal Area
Authors: Baumann Markus A. , Fluet Marie-Christine , Scherberger Hansjörg
Published: May 2009

To perform grasping movements, the hand is shaped according to the form of the target object and the intended manipulation, which in turn depends on the context of the action. The anterior intraparietal cortex (AIP) is strongly involved in the sensorimotor transformation of grasping movements, but the extent to which it encodes context-specific information for hand grasping is unclear. To explore this issue, we recorded 571 single-units in AIP of two macaques during a delayed grasping task, in which animals were instructed by an external context cue (LED) to perform power or precision grips on a handle that was presented in various orientations. While 55% of the recorded neurons encoded the object orientation from the cue epoch on, the number of cells encoding the grip type increased from 25% during the cue epoch to 58% during movement execution. Furthermore, a classification of cells according to the time of their tuning onset revealed differences in the function and anatomical location of early- versus late-tuned cells. In a cue separation task, when the object was presented first, neurons representing power or precision grips were activated simultaneously until the actual grip type was instructed. In contrast, when the grasp type instruction was presented before the object, type information was only weakly represented in AIP, but was strongly encoded after the grasp target was revealed. We conclude that AIP encodes context specific hand grasping movements to perceived objects, but in the absence of a grasp target, the encoding of context information is weak.
Plastic and Stable Electrophysiological Properties of Adult Avian Forebrain Song-Control Neurons across Changing Breeding Conditions
Authors: Meitzen John , Weaver Adam L. , Brenowitz Eliot A. , Perkel David J.
Published: May 2009

Steroid sex hormones drive changes in the nervous system and behavior in many animal taxa, but integrating the former with the latter remains challenging. One useful model system for meeting this challenge is seasonally breeding songbirds. In these species, plasma testosterone levels rise and fall across the seasons, altering song behavior and causing dramatic growth and regression of the song-control system, a discrete set of nuclei that control song behavior. Whereas the cellular mechanisms underlying changes in nucleus volume have been studied as a model for neural growth and degeneration, it is unknown whether these changes in neural structure are accompanied by changes in electrophysiological properties other than spontaneous firing rate. Here we test the hypothesis that passive and active neuronal properties in the forebrain song-control nuclei HVC and RA change across breeding conditions. We exposed adult male Gambel's white-crowned sparrows to either short-day photoperiod or long-day photoperiod and systemic testosterone to simulate nonbreeding and breeding conditions, respectively. We made whole-cell recordings from RA and HVC neurons in acute brain slices. We found that RA projection neuron membrane time constant, capacitance, and evoked and spontaneous firing rates were all increased in the breeding condition; the measured electrophysiological properties of HVC interneurons and projection neurons were stable across breeding conditions. This combination of plastic and stable intrinsic properties could directly impact the song-control system's motor control across seasons, underlying changes in song stereotypy. These results provide a valuable framework for integrating how steroid hormones modulate cellular physiology to change behavior.
Activation of Superficial Dorsal Horn Neurons in the Mouse by a PAR-2 Agonist and 5-HT: Potential Role in Itch
Authors: Akiyama Tasuku , Merrill Austin W. , Carstens Mirela Iodi , Carstens E.
Published: May 2009

Itch, an unpleasant sensation associated with the desire to scratch, is symptomatic of dermatologic and systemic disorders that often resist antihistamine treatment. Histamine-independent itch mediators include serotonin (5-HT) and agonists of the protease-activated receptor-2 (PAR-2). We used behavior, Fos immunohistochemistry, and electrophysiology to investigate if these mediators activate spinal dorsal horn neurons in a manner consistent with itch. Intradermal (id) injection of the PAR-2 agonist SLIGRL-NH2in the rostral back evoked bouts of directed hindlimb scratches over 20–30 min. Hindpaw injection of SLIGRL-NH2produced Fos staining in superficial dorsal horn which was then targeted for single-unit recording. Small id microinjections of SLIGRL-NH2or 5-HT identified responsive single units in the superficial dorsal horn of mice anesthetized with pentobarbital. Thirty-eight units characterized as wide dynamic range, nociceptive specific, or mechanically insensitive exhibited significantly increased firing after id SLIGRL-NH2for 9 min, to partial (25%) tachyphylaxis with repeated injection. A majority additionally responded to 5-HT (70%), mustard oil (79%), and capsaicin (71%). Seven units isolated with the 5-HT search stimulus exhibited significant and prolonged responses to 5-HT with tachyphylaxis to repeated injections. The majority also responded to SLIGRL-NH2, mustard oil, and capsaicin. The prolonged responses of superficial dorsal horn neurons to SLIGRL-NH2and 5-HT suggest a role in signaling itch. However, their responsiveness to algogens is inconsistent with itch specificity. Alternatively, such neurons may signal itch, whereas noxious stimulus levels recruit these and a larger population of pruritogen-insensitive cells to signal pain which masks or occludes the itch signal.
Inorganic-organic layered halide perovskites, with specific focus on PAMC, and its key and slot joint interlayers
Authors: Depmeier Wulf
Published: May 2009

A brief account is given on layered halide perovskitesA2BX4, and their relationships with the 3DABX3perovskites. The scientific history of the family of inorganic-organic hybrid structures of (CnH2n+1NH3)2MCl4, withM= Mn, Cd, Cu is described. The special case of PAMC, (C3H7NH3)2MnCl4, is shortly discussed, with special emphasis on the importance of non-bonded interlock layers interwoven with the topological layered perovskite structure and occurring accidentally on geometrical grounds in the propyl-compounds. These layers are believed to be the main reason for the uniqueness of these compounds in the series (CnH2n+1NH3)2MCl4, withn= 1–10 (at least). Modern achievements of investigations into other inorganic-organic hybrid perovskite-type layer structures are also addressed to.
Antropogén hatásra módosult fizikai, kémiai és biológiai tulajdonságok értékelése Szeged és környéke talajaiban
Authors: Puskás Irén , Prazsák István , Farsang Andrea , Maróy Péter
Published: May 2009

Az emberi
beavatkozásoknak köszönhetően Szeged város és környékének talajai jelentősen
megváltoztak mind fizikai, kémiai, mind biológiai tulajdonságaikat illetően. A
fizikai és kémiai talajtulajdonságok felmérése céljából 25 szelvény szintjeiből
történt mintavételen túl 10 helyszínen a mezofauna vizsgálatához szükséges
feltalajvételre is sor került az általunk előre kijelölt három zónában
(belváros, külváros, külterület).Atalajtulajdonságok
tárgyalása során világossá vált, hogy az egyes talajtani paraméterek milyen
fokú módosuláson mentek keresztül az intenzív emberi beavatkozások hatására. Az
összes oldott só kivételŕo
Talajtulajdonságok hatása a protonátmenettel járó felületi reeakciók kinetikájára
Authors: Rékási Márk
Published: May 2009

pH-sztat titrálással
vizsgáltuk 25 savanyú talaj pufferreakcióinak kinetikáját pH= 3 és pH = 8,2-es
értékeken. A reakciók leírására kéttagú, különböző sebességi állandójú,
kinetikailag elsőrendű reakció matematikai leírására alkalmas (1) egyenletet
használtuk. Megvizsgáltuk az egyenlet paraméterei és a talajtulajdonságok
közötti összefüggést. A következő eredményekre jutottunk:–A teljes
lúgfogyasztás értéke, azaz a bázis-pufferképesség a hidrolitikus savanyúsággal
mutatja a legszorosabb összefüggést. Ez azt jelenti, hogy a lúgos tartományban
a savanyúságot okozó ionok a legmeghatározóbb puffertényezők. Savas titrálásnál
viszont a kationcsere képessé_o
Pathophysiology of type 2 diabetes mellitus in youth: the evolving chameleon
Authors: Tfayli Hala , Arslanian Silva
Published: May 2009

Type 2 diabetes mellitus (T2DM) in children and adolescents is an important Public Health problem against the backdrop of the epidemic of childhood obesity. The clinical presentation of T2DM in youth is heterogeneous from minimal symptomatology to diabetic ketoacidosis. The increasing rates of youth T2DM have paralleled the escalating rates of obesity, which is the major risk factor impacting insulin sensitivity. Additional risk factors include minority race, family history of diabetes mellitus, maternal diabetes during pregnancy, pubertal age group and conditions associated with insulin resistance (IR) - such as polycystic ovary syndrome (PCOS). The pathophysiology of T2DM has been studied extensively in adults, and it is widely accepted that IR together with beta-cell failure are necessary for the development of clinical diabetes mellitus in adulthood. However, pathophysiologic studies in youth are limited and in some cases conflicting. Similar to adults, IR is a prerequisite, but beta-cell failure is necessary for progression from normal glucose tolerance to prediabetes and frank diabetes in youth. Even though rates of T2DM in youth are increasing, the overall prevalence remains low if compared with type 1 diabetes mellitus (T1DM). However, as youth with T1DM are becoming obese, the clinical distinction between T2DM and obese T1DM has become difficult, because of the overlapping clinical picture with evidence of islet cell autoimmunity in a significant proportion of clinically diagnosed youth with T2DM. The latter are most likely obese children with autoimmune T1DM who carry a misdiagnosis of T2DM. Further research is needed to probe the pathophysiological, immunological, and metabolic differences between these two groups in the hopes of assigning appropriate therapeutic regimens. These challenges combined with the evolving picture of youth T2DM and its future complications provide unending opportunities for acquisition of new knowledge in the field of childhood diabetes.
Epidemiological and molecular mechanisms aspects linking obesity and cancer
Authors: Osório-Costa Felipe , Rocha Guilherme Z. , Dias Marília M. , Carvalheira José B. C.
Published: May 2009

About 25% of cancer cases globally are due to excess weight and a sedentary lifestyle. These results are alarming, as the world knows a pandemy of obesity and, in consequence, insulin resistance. Obesity may increase risk for various cancers by several mechanisms, including increasing sex and metabolic hormones, and inflammation. Here, we present a review of epidemiological and molecular evidences linking obesity and cancer - particularly colorectal, post-menopausal breast, endometrial, pancreatic, high grade prostate, hepatocellular, gallbladder, kidney and esophageal adenocarcinoma. The expected striking increase in the incidence of cancer in the near future related to obesity turns the knowledge of this field of great impact as it is needed to the development of strategies to prevent and treat this disease.
Incidence and prevalence rates of inflammatory bowel diseases, in midwestern of São Paulo State, Brazil
Authors: Victoria Carlos Roberto , Sassak Ligia Yukie , Nunes Hélio Rubens de Carvalho
Published: May 2009

CONTEXT:The incidence and populational prevalence of inflammatory bowel diseases, hitherto unknown in Brazil, were estimated for a region in the Midwest of São Paulo State, Brazil. METHODS: Using a sequential registry of 115 adult patients (>15 years old) with inflammatory bowel diseases - exclusively residing in the studied region with 533,508 inhabitants (2005) and attended at the reference hospital during a 20 year interval (1986-2005) - were estimated, in four consecutives periods of 5 years each, the incidences according to gender, type of the disease and the prevalence of these diseases, and its inner-relations evaluated by the Poisson regression model. RESULTS: The inflammatory bowel diseases in the studied region predominated among young, white race and people living in urban area, and the incidence on the female population rose during this period. The incidence of ulcerative colitis were higher than Crohn's disease and non-classified colitis, and showed a progressive increase in the first three periods with a decrease in the last one (2001-2005), where the observed rates of ulcerative colitis, Crohn's disease and non-classified colitis were 4.48, 3.50 and 1.75 cases/100,000 inhabitants, with prevalence of 22.61, 14.81, 5.65, 2.14 cases/100,000 inhabitants for total inflammatory bowel diseases. CONCLUSION: The inflammatory bowel diseases incidence in the studied area was as low as in other countries of Latin America and smaller than that found in countries of South Europe. The crescent prevalence justifies the policies to adequate medical cares for inflammatory bowel diseases patients in this area.
Trombose de veia porta após desconexão ázigo-portal e esplenectomia em pacientes esquistossomóticos: Qual a real importância?
Authors: Makdissi Fábio Ferrari , Herman Paulo , Machado Marcel Autran C. , Pugliese Vincenzo , D'Albuquerque Luiz Augusto Carneiro , Saad William A.
Published: May 2009

CONTEXTO: A complicação mais frequente após a desconexão ázigo-portal e esplenectomia em doentes com esquistossomose mansônica hepatoesplênica é a trombose da veia porta. OBJETIVOS:Avaliar a incidência, os fatores preditivos dessa complicação, assim como, a evolução clínica, laboratorial, endoscópica e ultrassonográfica desses pacientes. MÉTODOS: Foram analisados retrospectivamente os prontuários de 155 doentes esquistossomóticos submetidos a desconexão ázigo-portal e esplenectomia. RESULTADOS: Trombose de veia porta foi observada em 52,3% dos pacientes, sendo 6,5% de trombose total e 45,8% de trombose parcial. Os pacientes que evoluíram com trombose de veia porta apresentaram mais frequentemente diarreia no pós-operatório. Febre foi evento habitual que ocorreu em 70% dos casos, mais frequente, entretanto, nos doentes com trombose total da veia porta (100%). Trombose de veia mesentérica superior ocorreu em quatro doentes (2,6%), sendo mais frequente entre os com trombose total da veia porta. Não se encontrou diferença estatística quanto aos parâmetros clínicos, laboratoriais, endoscópicos e recidiva hemorrágica no pós-operatório tardio, quando comparados os pacientes com e sem trombose portal. CONCLUSÕES: A trombose de veia porta no pós-operatório da desconexão ázigo-portal e esplenectomia é evento frequente, sem nenhum fator preditivo para sua ocorrência; na maioria dos casos a trombose é parcial e apresenta evolução benigna, com baixa morbidade; trombose total da veia porta está mais frequentemente associada à trombose da veia mesentérica superior, com elevada morbidade; a trombose da veia porta, parcial ou total, não acarretou complicações no período pós-operatório tardio.
Poda em uvaieira (Eugenia uvalha CAMB.)
Authors: Sampaio V.R.
Published: May 2009

Uvaieiras com quatro anos de idade foram submetidas a podas no mês de agosto de 1984, consistindo a observação em três tratamentos: a) Controle, sem podas, b) Corte de ramos finos, com até 5mm de diâmetro e c) Corte de ramos com até 10mm de diâmetro. A poda mostrou-se muito prejudicial à produção de frutos ocorrida no mesmo ano, apresentando médias de 4,118, 0,860 e 0,230 quilogramas por planta, para os tratamentos controle, poda leve e poda severa,respectivamente. Na safra seguinte, as produções dos diferentes tratamentos tenderam a equilíbrio ocorrendo médias de produção de 7,297, 5,111 e 4,531 quilogramas por planta para os tratamentos controle, poda leve e poda severa.
Efeito do tratamento térmico do leite na qualidade do iogurte
Authors: Araújo W.M.C. , Caruso J.G.B. , Oliveira A.J.de
Published: May 2009

O efeito do tratamento térmico do leite na qualidade do iogurte foi investigado aquecendo-se leite em banho-maria a 65°C por 30 min., 75°C por 10, 20 e 30 min., e 85°C por 10, 20 e 30 min.. A qualidade do iogurte foi avaliada por um painel de dez degustadores, utilizando-se a escala hedônica. Aos degustadores foi pedido julgarem o aroma, sabor e consistência do produto. A análise estatística dos resultados mostrou uma preferência significativa pelo produto feito com o leite tratado a 85°C por 30 minutos, embora os produtos obtidos a partir dos tratamentos térmicos a 75°C por 10, 20 e 30 minutos tenham sido efetivos em produzir o iogurte com as características de pH e ací-dez titulável desejáveis.
Nutrição mineral de seringueira (Hevea spp). X. Quantidade de al no substrato afetando a concentração e o acúmulo de Fe, Mn e Zn
Authors: Bueno N. , Haag H.P. , Pereira J.da P. , Viégas I.de J.M.
Published: May 2009

Com o propósito de comparar os efeitos de doses crescentes de Al sobre a concentração e acúmulo de Fe, Mn e Zn conduziu-se um experimento usando-se separadamente solução nutritiva usada por BOLLE-JONES e soluções de doses de Al que consistiram de 0, 5, 10, 15 20 e 25ppm, em que as plantas passaram vinte e quatro horas na solução nutritiva (sem Al) e vinte e quatro horas nas soluções de Al. Após noventa e cinco dias de tratamento as plantas foram coletadas e separadas em raiz, caule, folhas dos verticilos inferiores e folhas do último verticilo. Determinou-se as concentrações de Fe, Mn e Zn no material coletado. Observou-se que o Al estimula a concentração de Fe e Mn em todos os níveis de Al enquanto que o acúmulo desses micronutrientes é afetado a partir de 20ppm de Al na solução. A concentração de Zn na raiz e folhas do último verticilo é afetado a partir de 15ppm de Al na solução e o acúmulo deste nutriente é afetado a partir de 20ppm de Al na solução.
Eficiência relativa de diferentes frações granulometricas de calcários na neutralização da acidez dos solos, avaliada em laboratório
Authors: Bellingieri P.A. , Alcarde J.C. , Souza E.C.A. de
Published: May 2009

As frações granulométricas retidas nas peneiras n°s (ABNT) 5-10, 10-30, 30-50, e 50-60 de quatro calcários, sendo dois sedimentares e dois metamórficos, foram incubadas durante 160 dias com três tipos de solos, em condições de laboratório. A eficiência das frações na neutralização da acidez dos solos foi avaliada pela variação do pH. Os resultados permitiram concluir que a referida eficiência independe da natureza geológica do calcário mas depende do tipo de solo, sendo decrescente na seguinte ordem: LVd, LEd e LEm. Apesar da legislação atual normatizar as características físicas dos calcários, bem como os seus graus de eficiência, a presente pesquisa sugere novos valores para a eficiência relativa das diferentes frações granulometricas de calcários: fração maior do que 10:0%, de 30:35%; de 30-50:75% e menor que 50:100%.
Influência da secagem, armazenamento e embalagem nos resultados da análise química de terra para fins de fertilidade
Authors: Chitolina J.C. , Glória N.A.da , Boaretto A.E. , Curi P.R.
Published: May 2009

Amostras de terra provenientes de uma Terra Roxa Estruturada e um Latossol Vermelho Escuro textura média foram analisados quimicamente para se verificar a influência de embalagem (caixa de papelão saco de polietileno), tempo de armazenamento (1-32 dias) e processo de secagem (ao ar ou estufa a 60°C). A secagem foi o fator que mais influenciou a análise determinando variações nos resultados analíticos principalmente para pH e fósforo. O armazenamento apresentou influência apenas para fósforo trocável enquanto que a embalagem não influiu nos resultados. As variações dos resultados analíticos para pH, em função da secagem, e fósforo, em função da secagem e tempo de armazenamento, foram de ordem a alterar a interpretação da fertilidade quanto aos limites de classes.
Nutrição mineral do cafeeiro III. Recrutamento de B, Cu, Fe, Mn e Zn pelo cafeeiro (Coffea arabica L. cv. Catuai) com dois, três, quatro e cinco anos de idade; nas fases fenológicas de repouso, granação e maturação vegetando em um latossolo vermelho amarelo, fase cerrado
Authors: Cietto S. , Haag H.P.
Published: May 2009

Em uma plantação de cafeeiros (Coffea arabica cv. Catuai) com dois, três, quatro e cinco anos de idade no campo, situada em Latossolo Vermelho Amarelo, fase cerrado no município de Salto, SP, determinou-se o recrutamento de micronutrientes no caule, ramos, folhas e frutos, durante as fases fenológicas de repouso, granaçao e maturação. Concluiu-se que: A maior acumulação de cobre, manganês e zinco ocorre nos meses de julho, janeiro e junho em cafeeiros com cinco anos de idade. A acumulação de boro e ferro varia em função das épocas. Em janeiro e junho o acúmulo de ferro nao mostrou diferenças entre as idades. O cafeeiro aos cinco anos de campo exporta através da colheita, em função do conteúdo total da planta 30% de B, 46% de Cu, 26% de Fe, 14% de Mn e 25% de Zn.
Ácaro da leprose Bvevipalpus phoenicis (Geijskes, 1939): combate experimental em laranjeiras
Authors: Mariconi F.A.M. , Rangel R.C. , Hamamura R. , Clari A.I. , Mesquita L.F. , Cardoso M.A.C. , Regitano E.B.
Published: May 2009

Com o objetivo de combater o ácaro da leprose foi montado um campo experimental com os seguintes tratamentos: A) testemunha; B) clofentezina, 9,45g; C) clofentezina, 9,45g + alquenóis multimetílicos, 0,4g; D) quinometionato, 25,Og; E) quinometionato, 37,5g; F) piretróide RU-1.000, l,76g; G) piretróide RU-1.0Q0, 2,0g; H) dicofol, 37,0g (tratamento padrão). As quantidades citadas são de ingredientes ativos em 1000 litros de calda (Tabela 1). Cada laranjeira foi pulverizada com 6 litros de calda, aplicada com pulverizador costal motorizado. Foram feitas 6 avaliações: a prévia (03 dias antes da pulverização) e 5 pos-aplicaçao (05, 14, 18, 26 e 35 dias após a aplicação). Pela análise dos resultados obtidos verifica-se que os tratamentos B, F, G e H. foram os mais eficientes. Os resultados da redução real podem ser observados na Tabela 2.
Ácaros do pinheiro-do-Paraná em Lages, Santa Catarina
Authors: Fenilli R. , Flechtmann C.H.W.
Published: May 2009

Coletas quinzenais de ácaros de ramos do Pinheiro-do-Paraná, Araucária angustifolia, em Lages, Santa Catarina, revelaram a presença, durante um ano (Setembro de 1983 a Agosto de 1984) das espécies fitófagas Oligonychus urunguis (Jacobi) e Tydeus formosus (Cooreman) e de ácaros predadores da família Phytoseiidae, dos gêneros Amblyseius e Proprioseiopsis. Também ácaros oribatídeos foram coletados durante todo o ano. De ocorrência mais restrita foram obtidos ácaros das famílias Ascidae, Bdellidae, Cheyletidae e Acaridae. O método de coleta batendo-se o material vegetal sobre tela e bandeja revelou-se pouco mais eficiente do que o emprego do funil de Tullgren.
Ácaro branco do algodão Polyphagotarsonemus latus (Banks, 1904) (Acari: Tarsonemidae) e ensaio de combate químico
Authors: Rangel R.C. , Hamamura R. , Regitano E.B. , Arashiro F.Y. , Rangel M.C. , Clari A.I. , Mariconi F.A.M.
Published: May 2009

Com o intuito de avaliar o desempenho de produtos químicos no combate ao "ácaro branco" Polyphagotarsonemus latus (Banks, 1904) em algodoeiro, instalou-se o presente trabalho. Os 7 tratamentos, com 4 repetições, foram os seguintes: A) testemunha; B) triazofós, 300g; C) triazofós, 150g + feromônios (alquenóis multimetílicos), 4,77g; D) propargite, 1,080g; E) abamectina, 6g + feromônios (alquenóis multimetílicos), 6,67g; F) profenofós, 400g; G) enxofre, 3.000g. As quantidades acima são de ingredientes ativos por hectare. Os melhores resultados foram conseguidos pelo triazofós, seguido pelo enxofre e as duas misturas com feromônios.
Combate ao ácaro rajado Tetranychus urticae Koch, 1836 em algodão, com defensivos químicos
Authors: Swart M. , Pazini M.R. , Ciniglio Neto F. , Rangel R.C. , Mariconi F.A.M.
Published: May 2009

Com o objetivo de se verificar a ação de vários defensivos agrícolas contra o ácaro rajado do algodão, um campo experimental foi instalado. Os tratamentos e suas quantidades de ingredientes ativos, por hectare, foram: A) testemunha; B) dicofol, 369,6g; C) dicofol, 739,2g; D) propargite, 1.080g; E) silaneofane, 200g; F) bifentrina, 60g; G) abamectina, 7,2g. Resultados ótimos não foram obtidos com nenhum tratamento: todavia, o propargite mostrou resultados relativamente bons após 03, 06 e 12 dias da pulverização e a bifentrina e abamectina somente aos 06 dias.
Levantamento florístico e fitossociológico dos canteiros do Parque da Escola Superior de Agricultura "Luiz de Queiroz"
Authors: Gonldenberg R. , Rodrigues R.R. , Essoe B.
Published: May 2009

O parque da ESALQ, implantado no início do século pelo arquiteto paisagista Arsênio Puttemans, tem hoje grande valor científico e histórico, além de se constituir na principal área verde da cidade de Piracicaba. Visando o conhecimento detalhado da vegetação arbustivo-arbórea. Foram plaqueados, mapeados, medidos (altura e DAP) e identificados todos os indivíduos com DAP maior ou igual a 5 cm. Os dados foram analisados em computador, usando o programa FITOPAC, de autoria de Shepherd, G.J. (UNICAMP). Neste trabalho estão apresentados os resultados de três canteiros. O primeiro, ocupando uma área de 382 m², teve amostradas 24 espécies distribuídas por 13 famílias, num total de 88 indivíduos. O valor do índice de diversidade H' foi de 2,53, sendo que a espécie de maior destaque no IVC foi Aspidosperma ramiflorum Mull.Arg.. O segundo canteiro, ocupando uma área de 2694 m², teve amostradas 21 famílias representadas por 33 espécies, num total de 212 indivíduos. O valor do índice de diversidade H' foi de 2,68 e destacaram-se duas espécies na ordenação do IVC: Esenbeckia leiocarpa Engl, e Tipuana tipu (Benth.) O.Kuntze. O terceiro canteiro, ocupando 3786 m², teve amostradas 28 famílias, representadas por 66 espécies e 419 indivíduos. O índice H' obtido foi de 3,50. Neste canteiro as espécies com destaque na ordenação do IVC foram: Aspidosperma cylindrocarpum Mull.Arg. , Machaerium villosum Vog., Centrolobium tomentosum Guill. e Myrcia laurotteana Camb.
Efeito de diferentes porta-enxertos no vigor e produtividade da laranjeira 'pera' (Citrus sinensis L.) Osbeck)
Authors: Mourão Filho Francisco de Assis Alves , Mischan Martha Maria , Salibe Ary Apparecido
Published: May 2009

O presente trabalho teve como objetivo avaliar a influência de oito porta-enxertos no vigor, produção e produtividade da laranjeira 'Pera'. Para a realização deste estudo utilizaram-se plantas de um experimento instalado na Fazenda Experimental Lageado da UNESP, Campus de Botucatu, São Paulo. O delineamento estatístico adotado foi o de blocos ao acaso. Os porta-enxertos estudados foram: limoeiros 'Cravo', 'Volkameriano' e 'Rugoso da Flórida', tangerineiras 'Cleópatra' e 'Sunki', laranjeira 'Caipira', 'Trifoliata' e citrange 'Carrizo'. Os resultados revelaram que os porta-enxertos tangerineiras 'Cleópatra' e 'Sunki' e limoeiro 'Rugoso da Flórida' induziram a um maior desenvolvimento das plantas da laranjeira 'Pera'. Os porta-enxertos limoeiros 'Volkameriano' , 'Rugoso da Flórida' e 'Cravo' e as tangerineiras 'Sunki' e 'Cleópatra' induziram as maiores produções totais. Os maiores valores de índice de eficiência (produção (kg)/m³ copa) foram constatados em plantas sobre 'Trifoliata', citrange 'Carrizo' e limoeiro 'Cravo'. Características desses porta-enxertos são discutidas.
Modificações da qualidade de vida sexual de obesos submetidos à cirurgia de Fobi-Capella
Authors: Araújo Arakén Almeida de , Brito Ana Maria de , Ferreira Moacir de Novaes Lima , Petribú Kátia , Mariano Maria Helena de Araújo
Published: May 2009

OBJETIVO: Analisar as modificações na qualidade de vida sexual de obesos, proporcionadas pela redução do peso corpóreo, após a realização da gastroplastia à Fobi-Capella. MÉTODOS: Estudo quantitativo, prospectivo e longitudinal com cortes transversais, realizado entre março de 2005 e março de 2007, com 21 obesos mórbidos. Critérios de inclusão: idade de 20 a 50 anos, índice de massa corpórea (IMC) =40 Kg/m² e insucesso em tentativas de tratamento clínico para obesidade nos últimos dois anos. Coleta de dados clínicos em prontuários e aplicação de questionário específico com questões relativas à função sexual, realizadas antes e seis meses após a cirurgia. Os escores obtidos foram analisados com o auxilio do programa Epi-Info6, empregando o teste T de student para amostras pareadas. RESULTADOS: O valor total aumentou seis meses após a cirurgia em 76,19%, permaneceu inalterado em 14,29% e diminuiu em 9,52%. Os domínios referentes a função erétil e a relação sexual aumentaram em 71,42%, ao desejo sexual em 52,38% e ao orgasmo em 28,57%. A satisfação sexual aumentou em 57,14%. As médias do valor total e dos seus domínios antes e seis meses após a cirurgia, exceto aquelas referentes ao orgasmo e ao desejo sexual, apresentam diferenças estatisticamente significativas. CONCLUSÃO: A qualidade de vida sexual em homens obesos melhora após a realização da gastroplastia à Fobi-Capella. Evidenciaram-se modificações favoráveis na função sexual desses indivíduos após a perda de peso.