bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intrastriatal malonate administration induces convulsive behaviour in rats
Authors: Fleck J. , Ribeiro M. C. P. , Schneider C. M. , Sinhorin V. D. G. , Rubin M. A. , Mello C. F. 
Published: May 2004

AbstractSummary: Malonic acidaemia is an inborn error of metabolism that accumulates malonate, a competitive succinate dehydrogenase (SDH; EC 1.3.99.1) inhibitor. The present study investigated the behavioural effects of unilateral intrastriatal administration of malonate (0.6, 1.8 or 6 µmol) in adult male Wistar rats (n= 10–13). Low doses of malonate (1.8 µmol) decreased exploratory activity and caused ipsiversive rotational behaviour. High doses of malonate (6 µmol) induced contralateral rotational behaviour and convulsive episodes. Malonate competitively inhibited SDH in mitochondrion‐enriched fractions from striatum (Ki=0.034±0.008 mmol/L). Interestingly, methylmalonate, which is a weaker SDH inhibitor than malonate (Ki=4.22±1.3 mmol/L), induced more convulsions than malonate at equimolar doses and did not cause ipsiversive rotational behaviour. It is suggested that the potency of SDH inhibition in vitro does not correlate positively with the convulsant potential of these inhibitors in vivo.
Carnitine‐acylcarnitine translocase deficiency: Identification of a novel molecular defect in a Bedouin patient
Authors: Galron D. , Birk O. S. , Kazanovitz A. , Moses S. W. , Hershkovitz E. 
Published: May 2004

AbstractSummary: Carnitine‐acylcarnitine translocase CACT deficiency is a very rare autosomal recessive disease. The neonatal phenotype of CACT deficiency is characterized by hypoketotic hypoglycaemia, hyperammonaemia, cardiomyopathy and skeletal muscle weakness culminating in early death. The disease is caused by mutations in the CACT gene, which encodes a protein transporting long‐chain fatty acid carnitine esters into the mitochondrial matrix. In this report, we describe the first case of CACT deficiency in the Bedouin population in Israel. The patient, the first son of consanguineous parents, was born at term after uneventful delivery. During the second day of life, he developed clinical signs of an acute metabolic crisis with severe hypoglycaemia and hyperammonaemia. Biochemical investigation suggested the diagnosis of CACT deficiency. Genetic molecular analysis confirmed this diagnosis by demonstrating that the affected child was homozygous for a novel missense mutation 793A>G, substituting glutamine by arginine (Q238R) in exon 7 of the CACT gene. Despite medical treatment and adequate nutrition, the patient died at 6 months of age.
The Resource Mothers Study of Maternal Phenylketonuria: Preliminary findings
Authors: Rohr F. , Munier A. , Sullivan D. , Bailey I. , Gennaccaro M. , Levy H. , Brereton H. , Gleason S. , Goss B. , Lesperance E. , Moseley K. , Singh R. , Tonyes L. , Vespa H. , Waisbren S. 
Published: May 2004

AbstractSummary: Women with phenylketonuria (PKU) must follow a strict low‐phenylalanine diet during pregnancy in order to protect the fetus from the deleterious effects of high maternal blood phenylalanine. The Resource Mothers Study of Maternal PKU was undertaken to determine whether a home visitation programme was effective in helping women with PKU attain blood phenylalanine control earlier during pregnancy. Resource Mothers were trained to provide social support and practical assistance to women with PKU during pregnancy. Eight metabolic clinics in the United States participated in the study. Women with PKU who were planning pregnancy or already pregnant were enrolled in the study and were treated with a low‐phenylalanine diet aimed at controlling blood phenylalanine to 120–360 µmol/L. They were randomly assigned to receive the services of a Resource Mother (RM group) or to a control group. Fifty women were enrolled, and accounted for 44 pregnancies which resulted in 28 live births, and 6 spontaneous abortions. Ten women are currently pregnant and another 6 have not become pregnant. Fifty‐six percent of enrolled women began the diet prior to becoming pregnant. Fifty‐three percent of women in the Resource Mother group were in metabolic control by 10 weeks gestation as compared to 39% in the control group. In addition, women who began diet after pregnancy and had a Resource Mother attained metabolic control earlier (mean gestational age of 22.4 weeks in the RM group vs 29.8 weeks in the control group). There was no difference in birth measurement z‐scores of offspring born to women in the RM group compared to controls. All but 4 women rated themselves as feeling worse about the diet at the end of pregnancy than at the beginning, and few women in either group remained on diet after delivery.
Diagnosis and Pathology of Unilateral Maxillary Sinus Opacification with or without Evidence of Contralateral Disease
Authors: Kaplan Brian A. , Kountakis Stilianos E. 
Published: May 2004

AbstractObjective: Determine the diagnostic criteria and etiology of complete unilateral maxillary sinus opacification.Methods: A prospective analysis was performed on patients presenting to a tertiary care rhinology practice with complaints of chronic rhinosinusitis or acute exacerbation. Sixty‐four consecutive patients were identified with unilateral maxillary sinus opacification on computed tomography (CT) scan after at least a 3‐week medical therapy for rhinosinusitis. The study population comprised 30 men and 34 women with a mean age of 47.0 years. All patients completed a symptom score questionnaire, received nasal endoscopy, and CT imaging. Patient symptoms and endoscopic and radiographic findings were analyzed to determine patterns related to final diagnosis.Results: All 64 patients underwent functional endoscopic sinus surgery. Each surgical specimen was sent for pathologic confirmation of the diagnosis. Sixteen mucoceles, 12 cases of nasal polyposis, 27 cases of acute or chronic sinusitis, 7 cases of inverting papilloma, and 2 cases of mycetoma were identified. Endoscopic and radiographic appearances were correlated with each disease process.Conclusion: Unilateral maxillary sinus opacification is a relatively common finding. Early identification of inverting papillomas and mucoceles may avoid delay in surgical intervention, whereas acute/chronic rhinosinusitis and nasal polyposis can initially be managed medically. Careful history, endoscopic examination, and radiographic studies can often determine the responsible disease process.
Intraepithelial Nerve Fibers Project Into the Lumen of the Larynx
Authors: Lima‐Rodrigues Manuel , Nunes Rui , Almeida Armando 
Published: May 2004

AbstractObjectives/Hypothesis: Studies on the morphology and location of the sensory receptors in the laryngeal mucosa have resulted in insufficient and sometimes conflicting data. In the present study the authors analyzed the distribution and morphology of sensory nerve plexuses and terminal fibers in the laryngeal mucosa of the rat.Study Design: Two groups of Male Wistar rats were used in this laboratory study; the larynx of the first group were used to analyse the sensitive innervation of its epithelium, whereas the larynx of the second group (controls) were tested for the specificity of the antibodies used.Methods: The larynges of the animals were entirely removed after perfusion, and coronal or horizontal sections were immunoprocessed for further randomized analysis of the mucosa. Primary afferents were detected by immunoreaction to two widely recognized markers of sensory nerves, calcitonin gene‐related peptide and substance P, and visualized using diaminobenzidine as a chromogen.Results: The nerve plexuses were more densely distributed in the dorsal half of the vocal folds and in the laryngeal aspect of the epiglottis. Dense networks of fine fibers with many varicosities en passant, immunoreactive for both calcitonin gene‐related peptide and substance P, occurred in the lamina propria and along the epithelial thickness. Calcitonin gene‐related peptide–immunoreactive and substance P–immunoreactive fibers extended across the epithelium and projected to the laryngeal lumen itself, reaching the space between the cilia.Conclusion: The projection of intraepithelial nerve fibers into the lumen of the larynx indicates that in the absence of mucus, nerve endings may be exposed and thus receive direct stimulation from airborne substances. Furthermore, it suggests that the laryngeal mucosa of the rat may constitute an experimental model for studying the direct activation or manipulation of primary afferents at the periphery and neurogenic inflammation.
Medialization Laryngoplasty With Strap Muscle Transposition for Vocal Fold Atrophy with or without Sulcus Vocalis
Authors: Su Chih‐Ying , Tsai Shang‐Shyue , Chiu Jeng‐Fen , Cheng Chu‐An 
Published: May 2004

AbstractObjective: Vocal fold atrophy with or without sulcus vocalis may result in a spindle‐shaped glottal incompetence (SGI). Because of varying drawbacks with all existing materials (e.g., Silastic block, Teflon, fat, etc.) used for medialization or augmentation of the atrophic vocal folds, there is a need to supplant these materials with a more stable, autologous tissue to correct the SGI.Study Design: Thirty‐two patients with vocal fold atrophy underwent medialization laryngoplasty with strap muscle transposition.Methods: Under local or general anesthesia, the thyroid lamina on the more affected side was vertically incised 5 mm off the midline. The inner perichondrium was carefully elevated from the overlying thyroid ala. Care was taken not to enter the laryngeal lumen. After dividing the thyrohyoid and cricothyroid membranes, the lamina was retracted laterally. To accommodate the muscle flap more easily, the caudal edge of the lamina was trimmed using a small burr. A bipedicled strap muscle flap was then transposed into the space between the lamina and the paraglottic soft tissue. The thyroid cartilages were carefully sutured back in place. All patients underwent pre‐ and postoperative voice evaluations including laryngostroboscopy, perceptual assessment, and acoustic and aerodynamic analyses. Patients who had been followed up for more than 3 months were enrolled in this study.Results: A total of 27 of the 32 patients with complete pre‐ and postoperative voice function measurements were included in the analysis. Vocal improvement was demonstrated in 26 of these 27 (96%) patients. No dyspnea or other major complications were noted in any patients.Conclusion: The results indicate that medialization laryngoplasty with strap muscle transposition is a prosthesis‐free, safe, and effective technique for correcting SGI caused by vocal fold atrophy.
Kir4.1 expression by astrocytes and oligodendrocytes in CNS white matter: a developmental study in the rat optic nerve
Authors: Kalsi Amanpreet S. , Greenwood Kirsty , Wilkin Graham , Butt Arthur M. 
Published: May 2004

AbstractDeletion studies in transgenic mice indicate that the potassium inward rectifying channel Kir4.1 is crucial for oligodendrocyte differentiation and has a special role in regulation of extracellular potassium (K+), a major function of astrocytes. However, there are conflicting reports on whether Kir4.1 is expressed by white matter astrocytes and oligodendrocytes, raising doubts over its functions. Here, we have examined Kir4.1 expression in astrocytes and oligodendrocytes of the rat optic nerve, a typical central nervous system white matter tract. Single and double immunofluorescence labelling was performed on frozen sections from optic nerves aged postnatal day (P)5, 10, 15, 20 and adult, using anti‐Kir4.1 antibodies and the glia‐specific antibodies glial fibrillary acidic protein (GFAP, astrocytes), carbonic anhydrase II (CAII, oligodendrocyte somata and processes) and myelin basic protein (MBP, oligodendrocyte myelin sheaths). The results demonstrate Kir4.1 expression in rows of glial cells as early as P5, and this pattern persisted throughout development and into adulthood, consistent with early expression of Kir4.1 on developing oligodendrocytes. Clear co‐expression of Kir4.1 and GFAP is first evident at P10 and increases to adult levels by P15 and P20, which correlates with the development of K+ regulation between P15 and P20. Astrocyte expression of Kir4.1 is localized to perivascular end‐feet and fine processes within the fascicles of myelinated axons, consistent with a role in K+ spatial buffering between nodes of Ranvier and blood vessels. By contrast, Kir4.1 is concentrated in the cell bodies of oligodendrocytes, and there is no apparent co‐expression with MBP+ myelin sheaths, suggesting oligodendroglial Kir4.1 channels are not involved in K+ regulation. The results support roles for Kir4.1 in both oligodendrocyte differentiation and K+ regulation by astrocytes.
Cerebral cortex three‐dimensional profiling in human fetuses by magnetic resonance imaging
Authors: Sbarbati Andrea , Pizzini Francesca , Fabene Paolo F. , Nicolato Elena , Marzola Pasquina , Calderan Laura , Simonati Alessandro , Longo Laura , Osculati Antonio , Beltramello Alberto 
Published: May 2004

AbstractSeven human fetuses of crown/rump length corresponding to gestational ages ranging from the 12th to the 16th week were studied using a paradigm based on three‐dimensional reconstruction of the brain obtained by magnetic resonance imaging (MRI). The aim of the study was to evaluate brain morphology in situ and to describe developmental dynamics during an important period of fetal morphogenesis. Three‐dimensional MRI showed the increasing degree of maturation of the brains; fronto‐occipital distance, bitemporal distance and occipital angle were examined in all the fetuses. The data were interpreted by correlation with the internal structure as visualized using high‐spatial‐resolution MRI, acquired using a 4.7‐T field intensity magnet with a gradient power of 20 G cm−1. The spatial resolution was sufficient for a detailed detection of five layers, and the contrast was optimized using sequences with different degrees of T1 and T2 weighting. Using the latter, it was possible to visualize the subplate and marginal zones. The cortical thickness was mapped on to the hemispheric surface, describing the thickness gradient from the insular cortex to the periphery of the hemispheres. The study demonstrates the utility of MRI for studying brain development. The method provides a quantitative profiling of the brain, which allows the calculation of important morphological parameters, and it provides informative regarding transient features of the developing brain.
A test of the hypothesis that a pathway of intraguild predation limits densities of a wolf spider
Authors: Lensing Janet R. , Wise David H. 
Published: May 2004

Abstract.  1. The high number of potential predatory interactions among the many arthropod generalist predators in terrestrial food webs makes exhaustive testing of interaction strengths by field experiments unfeasible. Thus, correlative patterns and laboratory observations of behaviour often form the basis of inferences about the strength of interaction pathways involving generalist predators (intraguild predation).2. Previous research has revealed a negative correlation between survival of juvenile wolf spiders of the genus Schizocosa (Lycosidae) and densities of another abundant spider family, the Gnaphosidae.3. Feeding trials in laboratory microcosms with a leaf‐litter substrate revealed that gnaphosids prey on juvenile Schizocosa in a structurally complex habitat.4. Gnaphosid densities were manipulated in two different field experiments, each conducted in a different year, in order to test directly the hypothesis that intraguild predation by gnaphosids limits densities of juvenile Schizocosa.5. Reducing numbers of gnaphosids, and doubling their numbers to two times the mean natural density, had no impact on the survival of juvenile Schizocosa in either field experiment. This finding suggests that correlative patterns in nature and feeding trials in the laboratory may at times provide deceptively simple and potentially misleading generalisations about the strengths of interaction pathways in complex networks of generalist predators.
Guards and thieves: antagonistic interactions between two ant species coexisting on the same ant‐plant
Authors: Raine Nigel E. , Gammans Nicola , Macfadyen Iain J. , Scrivner Gareth K. , Stone Graham N. 
Published: May 2004

Abstract.  1. The simultaneous occupation of a rare understorey ant‐acacia Acacia mayana by its guarding ant Pseudomyrmex ferrugineus, and an apparent opportunist parasite of the mutualism, the generalist ant Camponotus planatus is described. The two ant species occur together in 30.7% of the 26 mature A. mayana plants [23.5% of all trees (n = 34)] surveyed, but C. planatus is absent from saplings below 1 m in height (n = 8).2. While P. ferrugineus shows behaviour compatible with effective host‐tree defence, C. planatus does not attack phytophagous insects and appears ineffective as an ant‐guard. Camponotus planatus does, however, occupy swollen thorns (pseudogalls) on the host tree, and harvests nectar from extrafloral leaf nectaries. It is proposed that C. planatus is a parasite of the Acacia–Pseudomyrmex mutualism.3. Camponotus planatus does not harvest the second trophic reward produced by the tree for its Pseudomyrmex ant‐guards, protein‐rich food (Beltian) bodies. Camponotus planatus lack the specialised larval adaptations needed to use Beltian bodies as brood food, suggesting that this resource is potentially more resistant to exploitation by generalists than extrafloral nectar.4. In competition for access to nectaries, C. planatus effectively displaced P. ferrugineus in 99.8% of encounters. These results suggest not only that C. planatus is a parasite of this mutualism, but also that it is able to effectively counteract the aggression shown to other insects by the resident ant‐guards.
Bottom‐up and top‐down effects in a tritrophic system: the population dynamics of Plutella xylostella (L.)–Cotesia plutellae (Kurdjumov) on different host plants
Authors: Karimzadeh Javad , Bonsall Michael B. , Wright Denis J. 
Published: May 2004

Abstract.  1. The effects of host‐plant resistance on the population dynamics of the Diamondback moth, Plutella xylostella L., and its solitary parasitoid, Cotesia plutellae (Kurdjumov), were studied in replicated time‐series experiments.2. Host‐plant resistance did not affect the equilibrial abundance of the Diamondback moth, but it affected the dynamics of Diamondback moth populations.3. The mean population size of Diamondback moth showed no significant difference between Brassica rapa (a susceptible host plant) and Brassica napus (a partially resistant host plant) either in the presence or absence of the parasitoid.4. Time‐series analysis suggests that the dynamics of Diamondback moth on B. rapa were underpinned by delayed density‐dependent processes. In contrast, the dynamics of the moth on B. napus were influenced by a direct density‐dependent process.5. Although measures of short‐term parasitism showed a significantly higher rate of parasitism by C. plutellae on Diamondback moth feeding on B. napus compared with B. rapa, this individual performance does not translate into differences in the population dynamics. Analysis shows no significant difference in the persistence time of the population‐level interaction between the host and parasitoid on the two different host plants.
Liquidity Dynamics Across Small and Large Firms
Authors: Chordia Tarun , Shivakumar Lakshmanan , Subrahmanyam Avanidhar 
Published: May 2004

In this paper, we analyse cross‐sectional heterogeneity in the time‐series variation of liquidity in equity markets. Our analysis uses a broad time‐series and cross‐section of liquidity data. We find that average daily changes in liquidity exhibit significant heterogeneity in the cross‐section; the liquidity of small firms varies more on a daily basis than that of large firms. A steady increase in aggregate market liquidity over the past decade is more strongly manifest in large firms than in small firms. Absolute stock returns are an important determinant of liquidity. We investigate cross‐sectional differences in the resilience of a firm's liquidity to information shocks. We use the sensitivity of stock liquidity to absolute stock returns as an inverse measure of this resilience, and find that the measure exhibits considerable cross‐sectional variation. Firm size, return volatility, institutional holdings, and volume are all significant cross‐sectional determinants of this measure. (J.E.L.: D82, G10, G14).
Breaking up the collective farms
Authors: Ravallion Martin , Van De Walle Dominique 
Published: May 2004

AbstractThe de‐collectivization of Vietnamese agriculture was a crucial step in the country's transition to a market economy. The assignment of land‐use rights had to be decentralized and local cadres ostensibly had the power to capture this process. We assess the realized land allocation against explicit counter‐factuals. Depending on the region, we find that 95–99 percent of maximum aggregate consumption was realized by a land allocation that generated lower inequality overall, with the poorest absolutely better off. We attribute this outcome to initial conditions at the time of reform and actions by the centre to curtail the power of local elites.
Host‐marking behaviour as a quantitative signal of competition in the walnut fly Rhagoletis juglandis
Authors: Nufio César R. , Papaj Daniel R. 
Published: May 2004

Abstract.  1. Walnut‐infesting flies in the Rhagoletis suavis species group actively re‐use hosts for oviposition despite engaging in a genus‐typical host‐marking behaviour which, in other Rhagoletis groups, deters oviposition. In a study of the walnut fly, R. juglandis (Cresson), alternative hypotheses for the putative marking behaviour were evaluated.2. The oviposition site attraction hypothesis proposes that the host mark guides females to oviposition sites on occupied fruit. The competition intensity signal hypothesis proposes that the host mark is an indicator of the level of competition to be incurred if fruit are re‐used.3. In a field cage, females were presented simultaneously with fruit previously exposed to 25 females that were also allowed to oviposit and engage in the putative marking behaviour, and control fruit on which females were allowed only to oviposit. The occurrence of host marking reduced a female's propensity to oviposit from 46% to just over 10%, consistent with the competition intensity signal hypothesis only.4. In a laboratory assay, the duration of host marking was correlated positively with the size of a female's clutch. This result, also consistent with the competition intensity signal hypothesis, suggests that the amount of marking pheromone on a fruit is a reliable indicator of the number of eggs already deposited within.5. In a second field‐cage experiment, females were allowed to mark on fruit for 0, 10, 20, or 30 min and fruit were presented to test females. Whether or not females alighted on a particular host was not affected by the duration of marking; however, the frequency of both ovipositor probing and egg deposition decreased with increasing duration of marking. Consistent with the competition intensity signal hypothesis, this result suggests that the host mark permits females to assess the level of competition that a clutch will incur within re‐used fruit.