bluuebunny/crossref_metadata_2025_split huggingface dataset:
Male gamete development and early tapetal degeneration in cytoplasmic male‐sterile pepper investigated by meiotic, anatomical and ultrastructural analyses
Authors: Luo X.‐D. , Dai L.‐F. , Wang S.‐B , Wolukau J. N. , Jahn M. , Chen J.‐F. 
Published: July 2006

AbstractCytoplasmic male‐sterile (CMS) pepper (Capsicum annuum L.) is a useful germplasm for heterosis breeding, however, the process of male gamete development and the sterility mechanism is unclear. In the present study, the developmental sequence in CMS pepper and the causative factors responsible for pollen abortion were investigated through combined meiotic analysis, paraffin section observations, and transmission electron microscopy. Results from meiotic analysis showed that meiosis in a male‐sterile inbred line, CMS 21A, was normal, and uni‐nucleate pollen could be released from the tetrads of both CMS 21A and the fertile maintainer line 21B. However, only the uni‐nucleate pollen from CMS 21B could develop into functional gametes, while the uni‐nucleate pollen from the 21A went through a process of rupture, and the cellular components were released into the anther sac. Observations of paraffin sections viewed with the light microscope showed that the tapetum of CMS 21A at the uni‐nucleate stage swelled abnormally and was pressed against pollen grains of the locule. Further observations with transmission electron microscopy revealed that the mitochondria in CMS 21A tapetum were highly vacuolated, and there was no accumulation of sporopollenin on the surface of CMS 21A pollen, suggesting a close relationship between early degeneration of tapetum and CMS.
Search for partial resistance against Puccinia hordei in barley landraces from the Fertile Crescent
Authors: Shtaya M. J. Y. , Sillero J. C. , Rubiales D. 
Published: July 2006

AbstractA collection of 111 barley landraces from the Fertile Crescent was screened for resistance to barley leaf rust in the field and under controlled conditions. Large variation was observed for disease severity under field conditions. Accessions with high resistance because of hypersensitivity were identified. Also segregation was observed in some accessions, with individual plants showing hypersensitive reactions (IT ≤ 6). Partial resistance due to a reduction of infection in spite of a compatible infection was commonly found (19%). Resistance of 12 accessions selected for their low disease severity and high IT, was shown to be due to a prolonged latency period and increased percentage of early aborted colonies not associated with host cell necrosis. A high correlation was observed between the microscopic and macroscopic components of partial resistance.
Advantages of endoscopic submucosal dissection over conventional endoscopic mucosal resection
Authors: Shimura Takaya , Sasaki Makoto , Kataoka Hiromi , Tanida Satoshi , Oshima Tadayuki , Ogasawara Naotaka , Wada Tsuneya , Kubota Eiji , Yamada Tomonori , Mori Yoshinori , Fujita Fumitaka , Nakao Haruhisa , Ohara Hirotaka , Inukai Masami , Kasugai Kunio , Joh Takashi 
Published: July 2006

AbstractBackground:  Endoscopic mucosal resection is an established method for treating intramucosal gastric neoplasms. Conventional endoscopic mucosal resection has predominantly been performed using strip biopsy, but local recurrence sometimes occurs due to such piecemeal resection. Endoscopic submucosal dissection has recently been performed in Japan using new devices such as an insulation‐tip diathermic knife. The efficacy and problems associated with endoscopic submucosal dissection were evaluated by comparison with conventional endoscopic mucosal resection.Methods:  Treatment consisted of conventional endoscopic mucosal resection for 48 lesions from January 1999 to October 2002, and endoscopic submucosal dissection for 59 lesions from November 2002 to June 2005. Endoscopic submucosal dissection was performed using an insulation‐tip diathermic knife and flex and hook knives, as appropriate.Results:  For lesions ≥11 mm in size, en bloc resection rates were significantly higher with endoscopic submucosal dissection than with conventional endoscopic mucosal resection, but treatment time was significantly longer. En bloc resection rates were higher with endoscopic submucosal dissection than with conventional endoscopic mucosal resection in all areas. Treatment of lesions in the upper one‐third of the stomach took a long time using endoscopic submucosal dissection, and intraoperative bleeding was frequent. However, en bloc resection rates and intraoperative bleeding with endoscopic submucosal dissection were improved using various knives.Conclusions:  Endoscopic submucosal dissection can take a long time, but is superior to conventional endoscopic mucosal resection for treating intramucosal gastric neoplasms.
Association of pre‐S deletion mutant of hepatitis B virus with risk of hepatocellular carcinoma
Authors: Lin Chih‐Lin , Liu Chen‐Hua , Chen Wendy , Huang Wen‐Ling , Chen Pei‐Jer , Lai Ming‐Yang , Chen Ding‐Shinn , Kao Jia‐Horng 
Published: July 2006

AbstractBackground:  Pre‐S deletion mutant of hepatitis B virus (HBV) affects the expression of middle and small surface proteins, resulting in intracellular accumulation of large surface protein. The correlation between pre‐S deletion mutant and risk of hepatocellular carcinoma (HCC) in hepatitis B virus carriers remains unclear.Methods:  Using molecular assays, pre‐S deletion mutant of HBV were determined in 266 patients with chronic HBV genotype B or C infection. They included 202 asymptomatic carriers and 64 HCC patients.Results:  The overall prevalence of pre‐S deletion mutant was 16.5%. Hepatocellular carcinoma (odds ratio [OR], 3.23; 95% confidence interval [CI], 1.23–8.48, P = 0.02) and genotype C (OR, 3.19; 95%CI, 1.54–6.62, P = 0.002) were independently associated with the presence of pre‐S deletion mutant. The prevalence of pre‐S deletion mutant was comparable between HCC patients with genotype B and C infection. Nevertheless, in asymptomatic carriers, patients with genotype C infection were significantly associated with the presence of pre‐S deletion mutant compared to those with genotype B infection (20.8% vs 7.2%, P = 0.007). Compared with age‐ and genotype B‐matched asymptomatic carriers, young HCC patients (<50 years of age) had a significantly higher frequency of pre‐S deletion (3.4% vs 20%, P = 0.04).Conclusions:  Pre‐S deletion mutant is more frequent in HBV carriers with genotype C infection, and those with pre‐S deletion mutant may be associated with the development of HCC, irrespective of HBV genotype.
Abdominal obesity is an independent risk factor for erosive esophagitis in a Korean population
Authors: Kang Mun Su , Park Dong Il , Oh Se Yong , Yoo Tae Woo , Ryu Seung Ho , Park Jung Ho , Kim Hong Joo , Cho Yong Kyun , Sohn Chong Il , Jeon Woo Kyu , Kim Byung Ik 
Published: July 2006

AbstractBackground:  The relationship between obesity and gastroesophageal reflux disease (GERD) is controversial. The aim of the present study was to investigate the potential roles of body mass index (BMI) and waist circumference on GERD in a Korean population.Methods:  A total of 2457 subjects who visited the Kangbuk Samsung Hospital medical screening center for esophagogastroduodenoscopy from September 2004 to April 2005 were enrolled. All participants were given a questionnaire to determine reflux symptoms. Abdominal obesity was defined as a waist circumference ≥80 cm in women and ≥90 cm in men.Results:  The proportion of subjects in each BMI group was 68.9%, 28.7% and 2.4% for BMI <25, 25–30 and >30, respectively. The prevalence of abdominal obesity was 24.2%. The prevalence of reflux symptoms was 8.2%. Neither BMI nor abdominal obesity was significantly associated with reflux symptoms after adjustment. The prevalence of erosive esophagitis was 6.6%. There was a clear dose–response relationship between prevalence of erosive esophagitis and BMI (5.6%, 8.1% and 15.5% for BMI <25, 25–30 and >30, respectively, P = 0.002). Abdominal obesity was also associated with erosive esophagitis (odds ratio, 2.3; 95% confidence interval, 1.6–3.1). However, only the association between abdominal obesity and erosive esophagitis remained strong after adjustments.Conclusions:  Abdominal obesity rather than BMI is an independent risk factor for erosive esophagitis in the Korean population.
Technical feasibility of endoscopic submucosal dissection for gastric neoplasms in the elderly Japanese population
Authors: Kakushima Naomi , Fujishiro Mitsuhiro , Kodashima Shinya , Muraki Yosuke , Tateishi Ayako , Yahagi Naohisa , Omata Masao 
Published: July 2006

AbstractBackground and Aim:  Endoscopic submucosal dissection (ESD) is gaining acceptance among endoscopists for its efficacy, especially in Japan. Elderly patients often have operative risk due to comorbid diseases, and the feasibility of this treatment for such patients should be investigated. The aim of this study is to evaluate the efficacy and safety of ESD in elderly patients.Methods:  Among 308 gastric neoplasms treated by ESD from 2000 to 2004 in one hospital, 49 lesions were discovered in 42 elderly patients who were 75 years of age or older. Indication criteria for ESD were gastric neoplasms with no apparent massive submucosal invasion diagnosed by endoscopy. The en bloc plus R0 resection rate and complications were assessed in comparison with younger patients.Results:  The average age of the patients was 78.9 years (range 75–88 years). Of these patients, 24 (57%) had comorbid diseases. The complete en bloc plus R0 resection rate was 96% (47/49). Postoperative bleeding requiring emergency endoscopy occurred in three patients (7%). Perforation during ESD occurred in one patient (2%), and was immediately closed with endoclips and managed by conservative medical treatment. The en bloc plus R0 resection rate and complication rate in elderly patients were not significantly different from those of younger patients.Conclusions:  These results indicate that ESD could be a safe and reliable treatment for gastric neoplasms in elderly patients.
Functional screening of traditional antidepressants with primary cortical neuronal networks grown on multielectrode neurochips
Authors: Gramowski Alexandra , Jügelt Konstantin , Stüwe Simone , Schulze Roland , McGregor Gerard P. , Wartenberg‐Demand Andrea , Loock Jan , Schröder Olaf , Weiss Dieter G. 
Published: July 2006

AbstractWe optimized the novel technique of multielectrode neurochip recordings for the rapid and efficient screening of neuroactivity. Changes in the spontaneous activity of cultured networks of primary cortical neurons were quantified to evaluate the action of drugs on the firing dynamics of complex network activity. The multiparametric assessment of electrical activity changes caused by psychoactive herbal extracts from Hypericum, Passiflora and Valeriana, and various combinations thereof revealed a receptor‐specific and concentration‐dependent inhibition of the firing patterns. The spike and burst rates showed significant substance‐dependent effects and significant differences in potency. The effects of specific receptor blockades on the inhibitory responses provided evidence that the herbal extracts act on gamma‐amino butyric acid (GABA) and serotonin (5‐HT) receptors, which are recognized targets of pharmacological antidepressant treatment. A biphasic effect, serotonergic stimulation of activity at low concentrations that is overridden by GABAergic inhibition at higher concentrations, is apparent with Hypericum alone and the triple combination of the extracts. The more potent neuroactivity of the triple combination compared to Hypericum alone and the additive effect of Passiflora and Valeriana suggest a synergy between constituent herbal extracts. The extracts and their combinations affected the set of derived activity parameters in a concomitant manner suggesting that all three constituent extracts and their combinations have largely similar modes of action. This study also demonstrates the sensitivity, selectivity and robustness of neurochip recordings for high content screening of complex mixtures of neuroactive substances and for providing multiparametric information on neuronal activity changes to assess the therapeutic potential of psychoactive substances.
Inhibition of constitutive inward rectifier currents in cerebellar granule cells by pharmacological and synaptic activation of GABAB receptors
Authors: Rossi Paola , Mapelli Lisa , Roggeri Leda , Gall David , De Kerchove d'Exaerde Alban , Schiffmann Serge N. , Taglietti Vanni , D'Angelo Egidio 
Published: July 2006

Abstractγ‐Aminobutyric acid (GABA)B receptors are known to enhance activation of Kir3 channels generating G‐protein‐dependent inward rectifier K+‐currents (GIRK). In some neurons, GABAB receptors either cause a tonic GIRK activation or generate a late K+‐dependent inhibitory postsynaptic current component. However, other neurons express Kir2 channels, which generate a constitutive inward rectifier K+‐current (CIRK) without requiring G‐protein activation. The functional coupling of CIRK with GABAB receptors remained unexplored so far. About 50% of rat cerebellar granule cells in the internal granular layer of P19–26 rats showed a sizeable CIRK current. Here, we have investigated CIRK current regulation by GABAB receptors in cerebellar granule cells, which undergo GABAergic inhibition through Golgi cells. By using patch‐clamp recording techniques and single‐cell reverse transcriptase‐polymerase chain reaction in acute cerebellar slices, we show that granule cells co‐express Kir2 channels and GABAB receptors. CIRK current biophysical properties were compatible with Kir2 but not Kir3 channels, and could be inhibited by the GABAB receptor agonist baclofen. The action of baclofen was prevented by the GABAB receptor blocker CGP35348, involved a pertussis toxin‐insensitive G‐protein‐mediated pathway, and required protein phosphatases inhibited by okadaic acid. GABAB receptor‐dependent CIRK current inhibition could also be induced by repetitive GABAergic transmission at frequencies higher than the basal autorhythmic discharge of Golgi cells. These results suggest therefore that GABAB receptors can exert an inhibitory control over CIRK currents mediated by Kir2 channels. CIRK inhibition was associated with an increased input resistance around rest and caused a ∼ 5 mV membrane depolarization. The pro‐excitatory action of these effects at an inhibitory synapse may have an homeostatic role re‐establishing granule cell readiness under conditions of strong inhibition.
Postnatal development of the murine cerebellar cortex: formation and early dispersal of basket, stellate and Golgi neurons
Authors: Weisheit Gunnar , Gliem Michael , Endl Elmar , Pfeffer Peter L. , Busslinger Meinrad , Schilling Karl 
Published: July 2006

AbstractThe cerebellar cortex consists of a small set of neuronal cell types interconnected in a highly stereotyped way. While the development of cerebellar cortical projection neurons, i.e. Purkinje cells, and that of granule cells has been elucidated in considerable detail, that of cerebellar cortical inhibitory interneurons is still rather fragmentarily understood. Here, we use mice expressing green fluorescent protein (GFP) from the Pax2 locus to analyse the ontogenesis of these cells. Numbers of Pax2‐positive inhibitory interneuronal precursors increase following a classical sigmoidal growth curve to yield a total of some 905.000 ± 77.000 cells. Maximal cell increase occurs at about postnatal day (P)5.4, and some 75% of all inhibitory interneurons are generated prior to P7. Conjoint analysis of the developmental accruement of Pax2‐GFP‐positive cells and their cell cycle distribution reveals that, at least at P0 and P3, the numerical increase of these cells results primarily from proliferation of a Pax2‐negative precursor population and suggests that Pax2 expression begins at or around the final mitosis. Following their terminal mitosis, inhibitory cerebellar cortical interneurons go through a protracted quiescent phase in which they maintain expression of the cell cycle marker Ki‐67. During this phase, they translocate into the nascent molecular layer, where they stall next to premigratory granule cell precursors without penetrating this population of cells. These observations provide a quantitative description of cerebellar cortical inhibitory interneuron genesis and early differentiation, and define Pax2 as a marker expressed in basket and stellate cells, from around their final mitosis to their incipient histogenetic integration.
Early life modulators and predictors of adult synaptic plasticity
Authors: Akers Katherine G. , Nakazawa Masato , Romeo Russell D. , Connor John A. , McEwen Bruce S. , Tang Akaysha C. 
Published: July 2006

AbstractEarly life experience can induce long‐lasting changes in brain and behaviour that are opposite in direction, such as enhancement or impairment in regulation of stress response, structural and functional integrity of the hippocampus, and learning and memory. To explore how multiple early life events jointly determine developmental outcome, we investigated the combined effects of neonatal trauma (anoxia on postnatal day 1, P1) and neonatal novelty exposure (P2–21) on adult social recognition memory (3 months of age) and synaptic plasticity in the CA1 of the rat hippocampus (4.5–8 months of age). While neonatal anoxia selectively reduced post‐tetanic potentiation (PTP), neonatal novel exposure selectively increased long‐term potentiation (LTP). No interaction between anoxia and novelty exposure was found on either PTP or LTP. These findings suggest that the two contrasting neonatal events have selective and distinct effects on two different forms of synaptic plasticity. At the level of behaviour, the effect of novelty exposure on LTP was associated with increased social memory, and the effect of anoxia on PTP was not accompanied by changes in social memory. Such a finding suggests a bias toward the involvement of LTP over PTP in social memory. Finally, we report a surprising finding that an early behavioural measure of emotional response to a novel environment obtained at 25 days of age can predict adult LTP measured several months later. Therefore, individual differences in emotional responses present during the juvenile stage may contribute to adult individual differences in cellular mechanisms that underlie learning and memory.
Cell culture models to investigate the selective vulnerability of motoneuronal mitochondria to familial ALS‐linked G93ASOD1
Authors: Raimondi Andrea , Mangolini Alessandra , Rizzardini Milena , Tartari Silvia , Massari Silvia , Bendotti Caterina , Francolini Maura , Borgese Nica , Cantoni Lavinia , Pietrini Grazia 
Published: July 2006

AbstractMitochondrial damage induced by superoxide dismutase (SOD1) mutants has been proposed to have a causative role in the selective degeneration of motoneurons in amyotrophic lateral sclerosis (ALS). In order to investigate the basis of the tissue specificity of mutant SOD1 we compared the effect of the continuous expression of wild‐type or mutant (G93A) human SOD1 on mitochondrial morphology in the NSC‐34 motoneuronal‐like, the N18TG2 neuroblastoma and the non‐neuronal Madin–Darby Canine Kidney (MDCK) cell lines. Morphological alterations of mitochondria were observed in NSC‐34 expressing the G93A mutant (NSC‐G93A) but not the wild‐type SOD1, whereas a ten‐fold greater level of total expression of the mutant had no effect on mitochondria of non‐motoneuronal cell lines. Fragmented network, swelling and cristae remodelling but not vacuolization of mitochondria or other intracellular organelles were observed only in NSC‐G93A cells. The mitochondrial alterations were not explained by a preferential localization of the mutant within NSC‐G93A mitochondria, as a higher amount of the mutant SOD1 was found in mitochondria of MDCK‐G93A cells. Our results suggest that mitochondrial vulnerability of motoneurons to G93ASOD1 is recapitulated in NSC‐34 cells, and that peculiar features in network dynamics may account for the selective alterations of motoneuronal mitochondria.
Limb (hand vs. foot) and response conflict have similar effects on event‐related potentials (ERPs) recorded during motor imagery and overt execution
Authors: Carrillo‐de‐la‐Peña M. T. , Lastra‐Barreira C. , Galdo‐Álvarez S. 
Published: July 2006

AbstractAlthough there is substantial evidence that motor execution (M‐Ex) and motor imagery (M‐Im) share a common neural substrate, the role of the primary motor cortex (M1) during imagery is still a matter of debate. The present ERP study tries to clarify the functional similarity between the two processes in respect of (i) the engagement of the corresponding somatotopic M1 areas during execution and imagery of hand vs. foot movements; and (ii) the effect of conflicting information on response preparation. To this end, we recorded ERPs from 28 electrode sites in 19 participants while they performed a conflict task with congruent (target and flanker arrowheads pointing in the same direction) and incongruent (target pointing in the opposite direction to the flanker arrowheads) trials. We obtained the lateralized readiness potential (LRP), a component generated in M1, while subjects physically executed or mentally simulated the task. As expected by the somatotopic organization of M1, the LRP was of opposite polarity when foot, rather than hand, movements were prepared. The inversion of polarity also occurred during M‐Im, a result that strongly argues in favour of the participation of M1 in motor imagery. In incongruent trials, longer LRP latencies, a premature preparation of the incorrect response (positive deflection in LRP waveform) and a fronto‐central N2 component associated with response conflict appeared during both M‐Ex and M‐Im. Altogether, the results support the functional equivalence of the two processes and give support to the clinical use of M‐Im for the improvement and recovery of motor functions.
Apoptosis in the rat basal forebrain during development and following lesions of connections
Authors: Sophou Stavroula , Dori Ioanna , Antonopoulos John , Parnavelas John G. , Dinopoulos Athanasios 
Published: July 2006

AbstractEvidence suggests that neurotrophins are essential for the survival and phenotypic maintenance of cholinergic basal forebrain (BF) neurons. We evaluated the pattern of programmed cell death in the BF of the rat during development and after ablations of the cerebral cortex, a major target area and source of neurotrophins for BF neurons. We identified dying cells using the TUNEL (terminal deoxynucleotidyl‐transferase‐mediated dUTP‐biotin nick end labelling) method and confirmed their apoptotic morphology with electron microscopy. Moreover, we demonstrated the expression of the apoptotic marker active caspase‐3 in cells with features of apoptosis. TUNEL+ cells were present in the developing BF during the first two postnatal weeks. Their frequency peaked at postnatal day (P)1 and at P5. TUNEL used in conjunction with immunofluorescence for neuronal nuclear protein (NeuN) showed that, at both peak stages, the majority of apoptotic cells were neurons. Extensive lesions of the cerebral cortex at different ages (P0, P7 and P14) did not induce significant changes in the frequency of apoptotic BF neurons. However, they resulted in alterations in the morphological phenotype of choline acetyltransferase (ChAT)‐immunoreactive neurons in the BF, and a reduction in their number which was inversely proportional to the age at which the lesions were performed. We suggest that: (i) apoptosis is temporally coordinated with the morphological and neurochemical differentiation of BF neurons and the establishment of connections with their target areas; and (ii) cortical ablations do not affect the survival of BF neurons, but they influence the phenotype of cholinergic BF neurons.