bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of central corneal thickness and corneal curvature on the intraocular pressure measurement by Goldmann applanation tonometer and ocular blood flow pneumatonometer
Authors: Saleh Tarek A , Adams Morag , McDermott Bill , Claridge Kate G , Ewings Paul 
Published: July 2006

AbstractPurpose:  To assess the effects of central corneal thickness (CCT) and corneal curvature (CC) on the measurements of intraocular pressure (IOP) using Goldmann applanation tonometer (GAT) and the ocular blood flow pneumatonometer (OBFT).Methods:  104 patients were recruited from a glaucoma clinic. The CCT was measured using ultrasound pachymetry and the mean radius of CC using a keratometer. The IOP of each eye was measured using both GAT and the OBFT in a random order. Right eyes only were analysed for statistical purposes.Results:  The mean (±SD) IOP by GAT and OBFT was 18.2 mmHg (±4.4) and 18.2 mmHg (±4.0), respectively, with no statistically significant difference. IOP measurement with both instruments varied with CCT and CC. GAT showed an IOP increase of 0.40 mmHg per 10 µm increase of CCT and OBFT showed an increase of 0.38 mmHg in IOP per 10 µm increase of CCT. Multiple regression analysis showed that the effect of CCT was statistically significant (P < 0.001) on IOP recorded by both the GAT and OBFT but CC did not have a statistically significant effect on IOP recordings performed by either technique.Conclusion:  IOP measurements by GAT and OBFT are positively correlated with CCT with both tonometers being similarly affected. There was no significant correlation between CC and IOP measured by either tonometer.
Insulin‐like growth factor‐1 is an endogenous mediator of focal ischemia‐induced neural progenitor proliferation
Authors: Yan Yi‐Ping , Sailor Kurt A. , Vemuganti Raghu , Dempsey Robert J. 
Published: July 2006

AbstractThe adult mammalian brain contains resident neural progenitors in the subgranular zone of the dentate gyrus (DG) and the subventricular zone (SVZ) of the lateral ventricles. The proliferation of neural progenitors increases after focal cerebral ischemia in both of these regions, but the mechanisms that promote ischemia‐induced neural progenitor proliferation are not yet understood. We hypothesize that diffusible factors from the ischemic area play a role in this process as the DG is remote from the area of infarction. In this study, we observed that the peak of neural progenitor proliferation in the ipsilateral DG was between day 2 and day 4 of reperfusion after transient middle cerebral artery occlusion in adult spontaneously hypertensive rats. GeneChip and real‐time PCR analysis showed a three‐ to 102‐fold increase in the expression of 15 diffusible, mitogenic factors in the ischemic cortex at 3 days of reperfusion. Of these, insulin‐like growth factor‐1 (IGF‐1) showed increased protein expression in the activated astrocytes in the ischemic penumbra. In addition, the progenitors in both the SVZ and DG showed IGF‐1 receptor expression. Inhibiting IGF‐1 activity by introcerebroventricular infusion of IGF‐1 antibody significantly prevented the ischemia‐induced neural progenitor proliferation. These results indicate that IGF‐1 formed in the ischemic penumbra might be one of the diffusible factors that mediate post‐ischemic neural progenitor proliferation.
The role of GABAAβ2 subunit‐containing receptors in mediating the anticonvulsant and sedative effects of loreclezole
Authors: Groves James O. , Guscott Martin R. , Hallett David J. , Rosahl Thomas W. , Pike Andrew , Davies Amy , Wafford Keith A. , Reynolds David S. 
Published: July 2006

AbstractThe majority of inhibitory neurotransmission in the brain is mediated by the γ‐aminobutyric acid (GABA) type A (GABAA) receptor. The anticonvulsant loreclezole largely acts by potentiating GABAA receptors containing β2 and β3 subunits. We used a genetically modified mouse containing a loreclezole‐insensitive β2 subunit (β2N265S) to determine the role of this subunit in mediating the sedative and anticonvulsive effects of loreclezole. Sedation was assessed by measuring spontaneous locomotor activity and beam walking performance, and anticonvulsant efficacy was determined by pentylenetetrazole (PTZ) and amygdala kindling‐induced seizures. The β2N265S mice did not exhibit loreclezole‐mediated sedation as shown by normal locomotor activity and beam walking performance. However, loreclezole also failed to provide significant protection against PTZ‐induced seizures in the β2N265S mice. Reduced efficacy against amygdala‐kindled seizures, both acutely and over a 13‐day chronic dosing study, was also observed in β2N265S mice. These results suggest that the majority of the sedative effects and a significant proportion of the anticonvulsant efficacy of loreclezole are mediated via β2‐containing GABAA receptors.
Evidence for the involvement of purinergic P2X7receptors in outer retinal processing
Authors: Puthussery Theresa , Yee Peter , Vingrys Algis J. , Fletcher Erica L. 
Published: July 2006

AbstractExtracellular ATP mediates fast excitatory neurotransmission in many regions of the central nervous system through activation of P2X receptors. Although several P2X receptor subunits have been identified in the mammalian retina, little is known about the functional role of these receptors in retinal signalling. The purpose of the present study was to investigate whether purinergic P2X7receptors are involved in outer retinal processing by assessing receptor localization, degradation of extracellular ATP and the effect of functional activation of P2X7receptors on the electroretinogram (ERG). Using light and electron microscopy, we demonstrated that P2X7receptors are expressed postsynaptically on horizontal cell processes as well as presynaptically on photoreceptor synaptic terminals in both the rat and marmoset retina. Using an enzyme cytochemical method, we showed that ecto‐ATPases are active in the outer plexiform layer of the rat retina, providing a mechanism by which purinergic synaptic transmission can be rapidly terminated. Finally, we evaluated the role of P2X7receptors in retinal function by assessing changes to the ERG response of rats after intravitreal delivery of the P2X7receptor agonist benzoyl benzoyl ATP (BzATP). Intravitreal injection of BzATP resulted in a sustained increase (up to 58%) in the amplitude of the photoreceptor‐derived a‐wave of the ERG. In contrast, BzATP caused a transient reduction in the rod‐ and cone‐derived postreceptoral responses. These results provide three lines of evidence for the involvement of extracellular purines in outer retinal processing.
Regulation of the glutamate transporter EAAC1 by expression and activation of δ‐opioid receptor
Authors: Xia Peng , Pei Gang , Schwarz Wolfgang 
Published: July 2006

AbstractGlutamate transporters play an essential role in regulating temporal and spatial glutamate concentration in the synaptic cleft. The excitatory amino acid carrier 1 (EAAC1) is a neuronal‐specific transporter. Opioid receptors are found to modulate the glutamatergic system in brain, but the regulatory mechanism remains to be investigated. Here we report that the δ‐opioid receptor (DOR) co‐expressed with EAAC1 in Xenopus oocytes, but not the µ‐opioid receptor, down‐regulates EAAC1 function, and that [d‐Pen2,5]‐enkephalin stimulation of DOR can counteract the down‐regulation of the EAAC1‐mediated uptake. Results from co‐immunoprecipitation and immunofluorescence microscopy in both oocytes and rat hippocampal neurons indicate co‐localization and suggest direct interaction between DOR and EAAC1. The results suggest that DOR can reduce EAAC1 function by direct protein–protein interaction and that activation of DOR releases the inhibitory interaction. We suggest that this mechanism may be important for modulation of the glutamatergic system following opioid stimulation.
Dopamine neuronal responses in monkeys performing visually cued reward schedules
Authors: Ravel Sabrina , Richmond Barry J. 
Published: July 2006

AbstractDopamine neurons are important for reward‐related behaviours. They have been recorded during classical conditioning and operant tasks with stochastic reward delivery. However, daily behaviour, although frequently complex in the number of steps, is often very predictable. We studied the responses of 75 dopamine neurons during schedules of trials in which the events and related reward contingencies could be well‐predicted, within and across trials. In this visually cued reward schedule task, a visual cue tells the monkeys exactly how many trials, 1, 2, 3, or 4, must be performed to obtain a reward. The number of errors became larger as the number of trials remaining before the reward increased. Dopamine neurons frequently responded to the cues at the beginning and end of the schedules. Approximately 75% of the first‐cue responsive neurons did not distinguish among the schedules that were beginning even though the cues were different. Approximately half of the last‐cue responsive neurons depended on which schedule was ending, even though the cue signalling the last trial was the same in all schedules. Thus, the responses were related to what the monkey knew about the relation between the cues and the schedules, not the identity of the cues. These neurons also frequently responded to the go signal and/or to the OK signal indicating the end of a correctly performed trial whether a reward was forthcoming or not, and to the reward itself. Thus, dopamine neurons seem to respond to behaviourally important, i.e. salient, events even when the events have been well‐predicted.
Minocycline attenuates hypoxia–ischemia‐induced neurological dysfunction and brain injury in the juvenile rat
Authors: Fan Lir‐Wan , Lin Shuying , Pang Yi , Rhodes Philip G. , Cai Zhengwei 
Published: July 2006

AbstractTo investigate whether minocycline provides long‐lasting protection against neonatal hypoxia–ischemia‐induced brain injury and neurobehavioral deficits, minocycline was administered intraperitoneally in postnatal day 4 Sprague–Dawley rats subjected to bilateral carotid artery occlusion followed by exposure to hypoxia (8% oxygen for 15 min). Brain injury and myelination were examined on postnatal day 21 (P21) and tests for neurobehavioral toxicity were performed from P3 to P21. Hypoxic–ischemic insults resulted in severe white matter injury, enlarged ventricles, deficits in the hippocampus, reduction in numbers of mature oligodendrocytes and tyrosine hydroxylase‐positive neurons, damage to axons and dendrites, and impaired myelination, as indicated by the decrease in myelin basic protein immunostaining in the P21 rat brain. Hypoxic–ischemic insult also significantly affected physical development (body weight gain and eye opening) and neurobehavioral performance, including sensorimotor and locomotor function, anxiety and cognitive ability in the P21 rat. Treatments with minocycline significantly attenuated the hypoxia–ischemia‐induced brain injury and improved neurobehavioral performance. The protection of minocycline was associated with its ability to reduce microglial activation. The present results show that minocycline has long‐lasting protective effects in the neonatal rat brain in terms of both hypoxia–ischemia‐induced brain injury and the associated neurological dysfunction.
Neurotensin afferents of the ventral tegmental area in the rat: [1] re‐examination of their origins and [2] responses to acute psychostimulant and antipsychotic drug administration
Authors: Geisler Stefanie , Zahm Daniel S. 
Published: July 2006

AbstractThe ventral tegmental area (VTA) is involved in reward‐related behaviours and the actions of psychostimulant drugs. It is influenced by afferents expressing a variety of neurotransmitters and neuromodulators; the innervation containing neurotensin is among the densest of these. Intra‐VTA neurotensin activates dopaminergic neurons and plays an important role in the development of behavioural sensitization to psychostimulant drugs and possibly in schizophrenia. Using gold‐coupled wheatgerm agglutinin as retrograde tracer in combination with nonisotopic in situ hybridization for neurotensin mRNA or neurotensin antibodies after colchicine treatment, the present study was undertaken to demonstrate the neurotensinergic neurons projecting to the VTA and determine whether (and in which subpopulations) neurotensin expression is regulated in VTA‐projecting neurons after administrations of the psychostimulant drug methamphetamine or the antipsychotic haloperidol. This study reveals the lateral preoptico‐rostral lateral hypothalamic continuum and the medial preoptic area as main sources for the neurotensin afferents of the VTA. Fewer neurotensinergic, VTA‐projecting neurons are situated in the dorsal raphe, pedunculopontine and laterodorsal tegmental nuclei, lateral hypothalamic area, ventral endopiriform area, lateral septum, accumbens shell, parabrachial nucleus and different parts of the extended amygdala. The number of neurotensinergic VTA‐projecting neurons increased significantly only after methamphetamine administration and exclusively in the accumbens shell. It is concluded that the widespread neurotensinergic VTA‐projecting neurons, situated in areas involved in different reward‐related behaviours, are well suited to convey distinct reward information to the VTA. The up‐regulation of neurotensin expression selectively in VTA‐projecting neurons in the accumbens shell following methamphetamine administration may be an important factor in the development of behavioural sensitization.
Retinoic acid delineates the topography of neuronal plasticity in postnatal cerebral cortex
Authors: Wagner Elisabeth , Luo Tuanlian , Sakai Yasuo , Parada Luis F. , Dräger Ursula C. 
Published: July 2006

AbstractRetinoic acid is well recognized to promote neuronal differentiation in the embryonic nervous system, but how it influences the postnatal cerebral cortex remains largely unknown. The domain of highest retinoic acid actions in the cortex of the mouse constricts postnatally to a narrow band that includes the dorsal visual stream and the attentional and executive networks. This band of cortex, which is distinguished by the retinoic acid‐synthesizing enzyme RALDH3, exhibits signs of delayed maturation and enhanced plasticity compared to the surrounding cortex, as indicated by suppression of parvalbumin, neurofilament, cytochrome oxidase and perineuronal net maturation, and persistence of the embryonic, polysialated form of the neural cell‐adhesion molecule PSA‐NCAM. During the first postnatal week, the RALDH3‐expressing territory translocates in the caudal cortex from the medial limbic lobe to the adjacent neocortex. This topographical shift requires the neurotrophin NT‐3 because in mice lacking neuronal NT‐3 the RALDH3 enzyme maintains its early postnatal pattern up to adulthood. In the NT‐3‐null mutants, expression of the markers, whose topography colocalizes with RALDH3 in the normal cortex, matches the abnormal RALDH3 pattern. This indicates that the uneven retinoic acid distribution serves a role in patterning the maturation and to some extent function of the normal postnatal cerebral cortex.
Weight cycling in a very low‐calorie diet programme has no effect on weight loss velocity, blood pressure and serum lipid profile
Authors: Li Z. , Hong K. , Wong E. , Maxwell M. , Heber D. 
Published: July 2006

Background:  Many dieters lose and regain weight many times. It is unclear whether weight cycling is associated with adverse metabolic alterations or becomes more difficult with each attempt.Methods:  From 1988 to 2000, 2474 obese patients enrolled in our outpatient weight loss programme using a very low‐calorie diet. Caloric intake consisted of meal replacement supplying 700–800 cal/day.Results:  Our search distinguished 480 patients who had restarted the weight reduction programme at least once and up to four times (restarts). All subjects remained on the programme for 2 weeks or more each time. Mean initial weight loss was 21.3 kg for women and 28.8 kg for men. Rate of weight loss on first restart was not different from initial weight loss for women [1.6  vs. 1.4 kg/week; not significant (NS)] or for men (2.2  vs. 2.1 kg/week; NS). Of the 480 patients, 85 women and 51 men entered the programme three times. Rate of weight loss was similar for all three entries (1.4, 1.6 and 2.1 kg/week for first, second and third entry in women, NS; 2.1, 2.1 and 2 kg/week for men, NS). Only 20 women and 18 men entered the programme four times. The rate of weight loss was again similar for both men (NS) and women (NS) during each re‐entry. Cardiovascular risk factors including lipid profile and blood pressure were not adversely affected by weight cycling. In fact, lipid levels were lower at each restart.Conclusions:  The present study refutes the hypothesis that repeated dieting makes further dieting efforts more difficult.
Weight gain in type 2 diabetes mellitus
Authors: Jacob A. N. , Salinas K. , Adams‐Huet B. , Raskin P. 
Published: July 2006

Objective:  To investigate the potential causes of weight gain using insulin and combination therapy in type 2 diabetes.Design and methods:  This was an open‐label prospective study of 6‐month duration. Randomization was performed to insulin monotherapy, insulin and pioglitazone 30 mg daily, or insulin and metformin up to 2000 mg daily. Fifty‐seven subjects with poorly controlled type 2 diabetes were enrolled. The goal was to achieve a normal haemoglobin A1c (HbA1c) (<5.6%). Weight, resting energy expenditure (REE), reported energy intake and total energy expenditure, HbA1c, glycosuria, plasma leptin, ghrelin and adiponectin levels, and body fat were measured.Results:  A total of 49 subjects completed the study. At baseline, weight was 89.4 ± 22.9 kg and HbA1c was 11.1 ± 1.5%. Weight increased by 7.46, 7.60 and 7.12 kg in the monotherapy, metformin and pioglitazone groups, respectively [p = 0.98 between and <0.0001 within the groups by repeated measures‐analysis of variance (RM‐anova)]. HbA1c dropped to 7.8 ± 0.9% in the monotherapy arm, 7.6 ± 1.0% in the metformin arm and 7.2 ± 1.2% in the pioglitazone arm. Reported energy intake decreased. Glycosuria decreased but was not correlated with weight gain, while HbA1c changes were correlated with weight gain. REE per lean mass decreased (p = 0.04 by RM‐anova). The subcutaneous fat areas in the insulin monotherapy and pioglitazone arms showed increases (p = 0.02 and 0.004 respectively).Conclusions:  Weight gain was probably not due to an increase in food intake, while REE per lean body mass decreased, suggesting a role for increased efficiency in fuel usage due to improved glycaemic control. A drop in glycosuria probably also contributed to weight gain. In the monotherapy and pioglitazone arms, the subcutaneous fat areas increased.
Serum ghrelin levels are higher in Caucasian men than Japanese men aged 40–49 years
Authors: Matsunaga‐Irie S. , Ueshima H. , Zaky W. R. , Kadowaki T. , Evans R. W. , Okamura T. , Takamiya T. , Kita Y. , Kuller L. H. , Sekikawa A. 
Published: July 2006

Background:  Ghrelin, a 28‐amino‐acid gastric peptide hormone, has an appetite‐stimulating effect and controls the energy balance. Serum ghrelin levels inversely correlate with body mass index. Recently, several papers reported the ethnic difference in the ghrelin levels. To our knowledge, however, no studies have compared the serum ghrelin levels between Caucasians in the USA and the Japanese in Japan.Methods:  We conducted a cross‐sectional study of 189 men 40‐49 years of age (91 US Caucasians in the U.S. and 98 Japanese in Japan) to examine serum ghrelin levels and metabolic and other factors.Results:  Serum ghrelin levels correlated with waist circumferences and lipid profiles among Caucasian Americans and the Japanese. Serum ghrelin levels were significantly higher among Caucasian Americans than among the Japanese (904.5 (632.0, 1132.0) pg/mL, 508.0 (399.0, 1378.3) pg/mL (median and 95% confidence interval), respectively, P < 0.01), although Caucasian Americans were much more obese (BMI: 26.9 ± 3.3 kg/m2 versus 23.3 ± 3.1 kg/m2 respectively, P < 0.01). The ethnic difference remained after adjusting for metabolic factors, smoking status, and other factors (P < 0.01).Conclusions:  We have shown in our population‐based study that serum ghrelin levels among men aged 40‐49 are significantly higher in Caucasian Americans than in the Japanese in Japan. Reasons for the ethnic difference in the ghrelin levels are largely unknown and warrant further investigation.
Will climate change affect ectoparasite species ranges?
Authors: Cumming Graeme S. , Van Vuuren Detlef P. 
Published: July 2006

ABSTRACTAim  Over the next 100 years, human‐driven climate change and resulting changes in species occurrences will have global impacts on biodiversity, ecosystem function, and human health. Here we examine how climate change may affect the occurrences of tick species in Africa and alter the suitability of habitat outside Africa for African ticks.Location  Africa and the world.Methods  We predicted continental and global changes in habitat suitability for each of 73 African tick species, using multiple regression models in different climate change scenarios that cover a wide range of uncertainty.Results  Global habitat suitability improves for nearly all tick species under each of a representative range of eight climate change scenarios. Depending on the scenario, African tick species experience an average increase in global habitat suitability of between 1 million and 9 million square kilometres between 1990 and 2100.Main conclusions  The potential for successful translocations of ticks and their pathogens from Africa to the rest of the world is likely to increase over the next 100 years. Although the general trend is one of range expansion, there are winners and losers among tick species in each scenario, suggesting that tick community composition will be disrupted substantially by climate change. If this is also typical of other invertebrates, then climate change will disrupt not only the geographic location of communities but also their structure. Changes in tick communities are also likely to influence tick‐borne pathogens.
Haplotype Structure of FSHB, the Beta‐Subunit Gene for Fertility‐Associated Follicle‐Stimulating Hormone: Possible Influence of Balancing Selection
Authors: Grigorova M. , Rull K. , Laan M. 
Published: July 2006

SummaryFollicle‐stimulating hormone (FSH) is essential for human reproduction. The unique functions of this hormone are provided by the FSH receptor‐binding beta‐subunit encoded by the FSHB gene. Resequencing and genotyping of FSHB in three European, two Asian and one African population, as well as in the great apes (chimpanzee, gorilla, orangutan), revealed low diversity and significant excess of polymorphisms with intermediate frequency alleles. Statistical tests for FSHB showed deviations from neutrality in all populations suggesting a possible effect of balancing selection. Two core haplotypes were identified (carried by 76‐96.6% of each population's sample), the sequences of which are clearly separated from each other. As fertility most directly affects an organism's fitness, the carriers of these haplotypes have apparently had more success in human history to contribute to the next generation. There is a preliminary observation suggesting that the second most frequent FSHB haplotype may be associated with rapid conception success in females. Interestingly, the same haplotype is related to an ancestral FSHB variant shared with the ancestor of the great apes. The determination of the functional consequence of the two core FSHB variants may have implications for understanding and regulating human fertility, as well as in assisting infertility treatments.