bluuebunny/crossref_metadata_2025_split huggingface dataset:
Expression and significance of nerve growth factor receptor p75 in rats’ cathartic colonic wall
Authors: FAN Yi Hong , LU Bin , WANG Mei , NI Gui Bao , CHEN Ming Tao , XU Yi 
Published: October 2006

OBJECTIVE:  To investigate the expression of nerve growth factor receptor p75 in a normal and cathartic colon and its significance in the formation of the cathartic colon in rats.METHODS:  Sixty Sprague–Dawley rats were equally divided into normal control group, rhubarb group and phenolphthalein group. A model of the cathartic colon was constructed by gastric infusion with rhubarb or phenolphthalein in rats. The first dose of rhubarb and phenolphthalein was both 200 mg/kg/d and was increased by 200 mg/kg/d with each passing day. The last dose of rhubarb and phenolphthalein was 3200 mg/kg/d and 4200 mg/kg/d, respectively. The transit function of colon was measured by the Chinese ink expulsion test; the p75 in colon wall was determined by the immunohistochemical method.RESULTS:  The transit speed was much slower in the cathartic colon group than that in the control group. The imprinted Chinese ink length and the ratio of imprinted length/total colon length in the rhubarb‐induced cathartic colon was significantly shorter than that of the control group (77.38 ± 8.42 vs 94.25 ± 7.07 cm, P < 0.01). Those in the phenolphthalein‐induced group (83.38 ± 9.75 cm) were also significantly shorter than those of the control group but to a lesser degree (P < 0.05). p75 was abundantly expressed in the submucosal nerve plexus and weakly expressed in the myenteric plexus. The expression of p75 was much higher in the rhubarb‐induced group. The expression was strongly positive in the submucosal nerve plexus, significantly higher than that in the controls (P < 0.01). In the myenteric plexus, p75 was also highly expressed (P < 0.05). In the case of the phenolphthalein‐induced group, the expression of p75 was positive in the submucosal nerve plexus but was positive in the myenteric plexus of three rats only. The remaining rats were negative or weakly positive. This was not significantly different from that of the control group.CONCLUSIONS:  The abnormal expression of p75 in cathartic colon probably has some effect on the degeneration or apoptosis of neuronal cells in the enteric nerve plexus, with a subsequent pathological change of the enteric nervous system, and thus leads to abnormalities in colonic dynamics. The kind of lesion is probably associated with long‐term use of irritative cathartics.
ADULT CHOLEDOCHAL CYSTS: AN AUDIT OF SURGICAL MANAGEMENT
Authors: Woon Colin Y‐L. , Tan Yu‐Meng , Oei Chung‐Lie , Chung Alexander Y‐F. , Chow Pierce K‐H. , Ooi London L. P‐J. 
Published: October 2006

Background:  Choledochal cysts are rare congenital cystic dilatations of the biliary tree. Surgical management has evolved with regards to timing and surgical procedure of choice. We conducted a retrospective review of clinical presentation and surgical management of adult choledochal cysts.Methods:  Thirty‐two patients with choledochal cysts who underwent surgery between April 1991 and January 2005 were reviewed. There were 27 Todani Type I, 2 Type II, 2 Type IVA and 1 Type V cysts. Eighty‐four per cent of patients underwent complete cystectomy and hepaticojejunostomy. Seven patients had revision surgery comprising completion cystectomy and hepaticojejunostomy.Results:  There were no perioperative mortalities. Perioperative morbidity rate was 44% and the commonest complication perioperatively was wound infection (19%). Malignancy was noted in one histological specimen. This patient was disease free for 1 year postoperatively and was subsequently lost to follow up. No further malignancy was found on median follow up of 3.9 years (range, 1–14 years) for the other 31 patients.Conclusion:  Adult choledochal cysts are rare and are often non‐specific in their clinical presentation. In managing patients with choledochal cysts, it is important to first treat complications such as sepsis and pancreatitis before imaging of the biliary tree with endoscopic retrograde cholangiopancreatography or magnetic resonance cholangiopancreatography to evaluate the full extent and type of choledochal cyst. Surgical management should be planned single‐stage surgery comprising complete cyst resection, cholecystectomy and Roux‐en‐Y hepaticojejunostomy and should be carried out by hepatobiliary specialists. Excellent perioperative morbidity and mortality results are possible with this strategy. Malignancy is rare and was only noted in 3% but close follow up is warranted.
The effects of intense sound exposure on phase locking in the chick (Gallus domesticus) cochlear nerve
Authors: Furman Adam C. , Avissar Michael , Saunders James C. 
Published: October 2006

AbstractLittle is known about changes that occur to phase locking in the auditory nerve following exposure to intense and damaging levels of sound. The present study evaluated synchronization in the discharge patterns of cochlear nerve units collected from two groups of young chicks (Gallus domesticus), one shortly after removal from an exposure to a 120‐dB, 900‐Hz pure tone for 48 h and the other from a group of non‐exposed control animals. Spontaneous activity, the characteristic frequency (CF), CF threshold and a phase‐locked peri‐stimulus time histogram were obtained for every unit in each group. Vector strength and temporal dispersion were calculated from these peri‐stimulus time histograms, and plotted against the unit's CF. All parameters of unit responses were then compared between control and exposed units. The results in exposed units revealed that CF thresholds were elevated by 30–35 dB whereas spontaneous activity declined by 24%. In both control and exposed units a high degree of synchronization was observed in the low frequencies. The level of synchronization above approximately 0.5 kHz then systematically declined. The vector strengths in units recorded shortly after removal from the exposure were identical to those seen in control chicks. The deterioration in discharge activity of exposed units, seen in CF threshold and spontaneous activity, contrasted with the total absence of any overstimulation effect on synchronization. This suggested that synchronization arises from mechanisms unscathed by the acoustic trauma induced by the exposure.
Anticipatory control of long‐range phase synchronization
Authors: Gross Joachim , Schmitz Frank , Schnitzler Irmtraud , Kessler Klaus , Shapiro Kimron , Hommel Bernhard , Schnitzler Alfons 
Published: October 2006

AbstractEveryday human behaviour relies on our ability to predict outcomes on the basis of moment by moment information. Long‐range neural phase synchronization has been hypothesized as a mechanism by which ‘predictions’ can exert an effect on the processing of incoming sensory events. Using magnetoencephalography (MEG) we have studied the relationship between the modulation of phase synchronization in a cerebral network of areas involved in visual target processing and the predictability of target occurrence. Our results reveal a striking increase in the modulation of phase synchronization associated with an increased probability of target occurrence. These observations are consistent with the hypothesis that long‐range phase synchronization plays a critical functional role in humans' ability to effectively employ predictive heuristics.
Early postnatal changes in respiratory activity in rat in vitro and modulatory effects of substance P
Authors: Shvarev Y. N. , Lagercrantz H. 
Published: October 2006

AbstractDevelopmental changes in the respiratory activity and its modulation by substance P (SP) were studied in the neonatal rat brainstem–spinal cord preparation from the day of birth to day 3 (P0–P3). The respiratory network activity in the ventrolateral medulla was represented by two types of bursts: basic regular bursts with typical decrementing shape and biphasic bursts appearing after augmented biphasic discharges in inspiratory neurons. With advancing postnatal age the respiratory output was considerably modified; the basic rhythm became faster by 20%, whereas the biphasic burst rate, which was originally 15 times slower, declined further by 180% and the C4 burst duration significantly decreased by 20% due to reduced decay time without preceding changes in the central inspiratory drive. SP had an age‐dependent excitatory effect on respiratory activity. In the basic rhythm, SP could induce transient rhythm cessations on P0–P2 but not on P3. For the biphasic burst frequency, the sensitivity to SP significantly decreased from P0 to P3, whereas the range of SP‐induced changes increased. In both types of bursts, SP prolonged C4 burst duration due to increasing decay time. This effect was three times greater on P3 and did not depend on the central inspiratory drive. Our results suggest that the potency of SP to regulate the respiratory activity elevates during the early postnatal period. The developmental changes in the respiratory activity appear to represent the transient stage in the maturation of rhythm and pattern generation mechanisms facilitating adaptive behavior of a quickly growing organism.
Stereological methods reveal the robust size and stability of ectopic hilar granule cells after pilocarpine‐induced status epilepticus in the adult rat
Authors: McCloskey Daniel P. , Hintz Tana M. , Pierce Joseph P. , Scharfman Helen E. 
Published: October 2006

AbstractFollowing status epilepticus in the rat, dentate granule cell neurogenesis increases greatly, and many of the new neurons appear to develop ectopically, in the hilar region of the hippocampal formation. It has been suggested that the ectopic hilar granule cells could contribute to the spontaneous seizures that ultimately develop after status epilepticus. However, the population has never been quantified, so it is unclear whether it is substantial enough to have a strong influence on epileptogenesis. To quantify this population, the total number of ectopic hilar granule cells was estimated using unbiased stereology at different times after pilocarpine‐induced status epilepticus. The number of hilar neurons immunoreactive for Prox‐1, a granule‐cell‐specific marker, was estimated using the optical fractionator method. The results indicate that the size of the hilar ectopic granule cell population after status epilepticus is substantial, and stable over time. Interestingly, the size of the population appears to be correlated with the frequency of behavioral seizures, because animals with more ectopic granule cells in the hilus have more frequent behavioral seizures. The hilar ectopic granule cell population does not appear to vary systematically across the septotemporal axis, although it is associated with an increase in volume of the hilus. The results provide new insight into the potential role of ectopic hilar granule cells in the pilocarpine model of temporal lobe epilepsy.
Lesion of the pedunculopontine nucleus reverses hyperactivity of the subthalamic nucleus and substantia nigra pars reticulata in a 6‐hydroxydopamine rat model
Authors: Breit S. , Lessmann L. , Unterbrink D. , Popa R. C. , Gasser T. , Schulz J. B. 
Published: October 2006

AbstractThe pedunculopontine nucleus (PPN) and the subthalamic nucleus (STN) are reciprocally connected by excitatory projections. In the 6‐hydroxydopamine (6‐OHDA) rat model the PPN was found to be hyperactive. Similarly, the STN and the substantia nigra pars reticulata (SNr) showed increased activity in Parkinson's disease (PD) animal models. A lesion of the STN was shown to restore increased activity levels in the SNr of 6‐OHDA‐treated rats. As the STN and the PPN were reciprocally connected by excitatory projections and both structures were shown to be hyperactive in PD animal models, the present study was performed in order to investigate the changes in neuronal activity of the STN and SNr under urethane anesthesia after unilateral ibotenic acid lesioning of the PPN in animals with previous unilateral 6‐OHDA lesions of the substantia nigra pars compacta (SNc). The firing rate of STN neurons significantly increased from 10.3 ± 0.6 spikes/s (mean ± SEM) to 17.8 ± 1.8 spikes/s after SNc lesion and returned to normal levels of 10.8 ± 0.7 spikes/s after additional lesion of the PPN. Similarly, the firing rate of SNr neurons significantly increased from 19.0 ± 1.1 to 25.9 ± 1.4 spikes/s after SNc lesion, the hyperactivity being reversed after additional PPN lesion to 16.8 ± 1.2 spikes/s. The reversal of STN and SNr hyperactivity of 6‐OHDA‐treated rats by additional PPN lesion suggests an important modulatory influence of the PPN on STN activity. Moreover, these findings could indicate a new therapeutic strategy in PD by interventional modulation of the PPN.
Depolarization‐induced suppression of inhibition mediated by endocannabinoids at synapses from fast‐spiking interneurons to medium spiny neurons in the striatum
Authors: Narushima Madoka , Uchigashima Motokazu , Hashimoto Kouichi , Watanabe Masahiko , Kano Masanobu 
Published: October 2006

AbstractEndogenous cannabinoids (endocannabinoids) act as retrograde inhibitory messengers in various regions of the brain. We have recently reported that endocannabinoids mediate short‐term retrograde suppression of excitatory synaptic transmission from the neocortex to medium spiny (MS) neurons, the major projection neurons from the striatum. However, it remains unclear whether endocannabinoids modulate inhibitory transmission in the striatum. Here we show that depolarization of MS neurons induces transient suppression of inhibition that is mediated by retrograde endocannabinoid signalling. By paired recording from a fast‐spiking (FS) interneuron and an MS neuron, we demonstrated that FS–MS inhibitory synapses undergo endocannabinoid‐mediated retrograde suppression. We verified that GABAergic inhibitory terminals immunopositive for parvalbumin (PV), a marker for FS interneurons, expressed CB1 receptors. These PV–CB1 double‐positive terminals surrounded dopamine D1 receptor‐positive and D2 receptor‐positive MS neurons; these constitute direct and indirect pathways, respectively. These results suggest that endocannabinoid‐mediated retrograde suppression of inhibition influences information flow along both direct and indirect pathways, depending on the activity of MS neurons.
Reduced insulin secretion in normoglycaemic patients with β‐thalassaemia major
Authors: Angelopoulos N. G. , Zervas A. , Livadas S. , Adamopoulos I. , Giannopoulos D. , Goula A. , Tolis G. 
Published: October 2006

AbstractAims  To assess insulin sensitivity and secretion in the fasting state in regularly transfused patients with β‐thalassaemia major with normal glucose response during an oral glucose tolerance test and to estimate its possible relation to iron overload.Methods  We measured fasting glucose, insulin and C‐peptide levels in 24 patients with β‐thalassaemia major and 18 control subjects matched for age and body mass index. Insulin sensitivity and insulin release index were calculated according to the homeostasis model assessment (HOMA). Correlations with age, body mass index and serum ferritin were also calculated.Results  Fasting glucose levels in patients were increased compared with control subjects (5.5 ± 0.12 vs. 4.7 ± 0.13 mmol/l, mean ± sem, P < 0.001). Pancreatic B‐cell insulin secretion in the fasting state (estimated by SCHOMA) was lower in thalassaemic patients (SCHOMA 88.5 ± 11.11 vs. 184.3 ± 23.72 in control subjects, P < 0.001). Patients were then divided into those with impaired (IFG) and normal (NFG) fasting glucose. SCHOMA was higher in the patients with NFG compared with those with IFG patients (110.6 ± 17.63 vs. 66.3 ± 10.88, respectively, P < 0.05) but estimated insulin sensitivity (ISIHOMA) was similar. Plasma values of C‐peptide correlated positively with ferritin (r = 0.42, P = 0.04) and SCHOMA (r = 0.45, P = 0.02) and negatively with ISIHOMA (r = −0.43, P = 0.03).Conclusions  These results support the concept that impaired B‐cell function, as reflected by a reduction in the insulin secretion index, is present in β‐thalassaemic patients with normoglycaemia before changes in oral glucose tolerance tests are apparent.
Policies in the Polder: How Institutions Mediate between Norms and Practices of Rural Governance
Authors: Boonstra Wiebren Johannes 
Published: October 2006

AbstractMatching rural policy and practice has become increasingly difficult. Despite a shift from government to governance, a void is often perceived to exist between policy and practice. This article discusses two hypotheses on the emergence of such a void. The first argues that the void is a result of a process of value differentiation. The second explains the void as a result of a process of depoliticisation. This article examines whether these hypotheses hold true for Dutch rural policy. The analysis shows that though both hypotheses are true for a limited extent, neither succeeds in explaining the changes in Dutch (rural) policy on its own. Instead, it is argued that both are needed for a comprehensive analysis.
Non‐Economic Factors in Economic Geography and in ‘New Regionalism’: A Sympathetic Critique
Authors: HADJIMICHALIS COSTIS 
Published: October 2006

AbstractIn the current debate on local and regional development and after several ‘turns’, dominant critical models have found some security in institutional, cultural and evolutionary approaches. Interest today centres on success and competitiveness and how they are reproduced in a few paradigmatic regions. A distinctive feature of these regions and places is the embeddedness of certain non‐economic factors such as social capital, trust and reciprocity based on familiarity, face‐to‐face exchange, cooperation, embedded routines, habits and norms, local conventions of communication and interaction, all of which contribute to a region’s particular success. Although these approaches may not deny the forces of the capitalist space economy, they do not explicitly acknowledge them or take them on board and so they tend to discuss non‐economic factors and institutions as autonomous forces shaping development. This essay provides a critique of these concepts based on their (1) inadequate theorization, (2) depoliticized view of politics and de‐economized use of economics and (3) reduction of space to territory. The essay concludes that we need a far more penetrating renewal of radical critique of the current space economy of capitalism. Old concepts such as uneven development, the social and spatial division of labour, the geographical transfer of value, accumulation and imperialism must be combined with cultural and institutional issues, with those non‐economic factors mentioned above.
Staff Morale in Day Care Centres for Adults with Intellectual Disabilities
Authors: Mascha Katerina 
Published: October 2006

Background  Levels of burnout, job satisfaction and intended turnover of staff working in day care centres for adults with intellectual disabilities are investigated in relation to role clarity, staff support and supervision, and coping strategies used by staff.Materials and methods  Thirty six direct‐care staff of four day care centres in the UK were administered the Maslach Burnout Inventory, The Staff Support Questionnaire (SSQ), and The Shortened Ways of Coping (Revised) Questionnaire (SWC‐R).Results  Although staff reported high levels of job satisfaction, they experienced moderate degrees of emotional exhaustion and personal accomplishment and reported a high propensity to leave the service. Factors identified as relating to staff morale were staff support and supervision, role clarity, wishful thinking, staff cooperation, and other practical issues regarding the day‐to‐day running of the service.Conclusions  Staff in day care services for people with intellectual disabilities experience similar stressors to those experienced by staff in residential facilities with the informal culture of the service being of most importance to staff morale. Suggestions for the enhancement of staff morale are provided.
Exercise capacity and cardiovascular changes in patients with β‐thalassaemia major
Authors: Tocco Filippo , Crisafulli Antonio , Melis Franco , Loviselli Andrea , Lai Carlo , Concu Alberto 
Published: October 2006

SummaryDespite the introduction of deferoxamine, 50% of thalassaemia major patients die before the age of 35 years predominantly from iron induced heart failure. Indeed, the assessment of myocardial performance may be of particular interest since it can reveal an early myocardial dysfunction. By using impedance cardiography and mass spectrometry, we studied the cardiac function and the oxygen extraction ratio (O2ER) of 14 thalassaemic patients and 15 control healthy subjects during an incremental cycle‐ergometer test. The achieved mechanical power output and the relative O2 uptake did not reach any significant difference between groups. At the highest workload, O2ER reached significantly higher values in thalassaemic patients versus control subjects while the relationship between cardiac index (CI) and O2ER (CI/O2ER) decreased showing a lower contribution of cardiovascular system to maintain O2 uptake. Results of this study imply that CI/O2ER allows an early diagnosis of the iron induced myocardial dysfunction, whereas it is not clinically patent yet. To our knowledge, this is the first study revealing an O2ER pivotal role as compensatory mechanism to maintain a normal working capacity in subjects suffering from thalassaemia major.
Association Between Reduced Heart Rate Variability and Cognitive Impairment in Older Disabled Women in the Community: Women's Health and Aging Study I
Authors: Kim Dae Hyun , Lipsitz Lewis A. , Ferrucci Luigi , Varadhan Ravi , Guralnik Jack M. , Carlson Michelle C. , Fleisher Lee A. , Fried Linda P. , Chaves Paulo H. M. 
Published: October 2006

OBJECTIVES: To examine the independent association between heart rate variability (HRV), a marker of cardiac autonomic function, and cognitive impairment.DESIGN: Cross‐sectional analysis of baseline data from Women's Health and Aging Study I.SETTING: Urban community in Baltimore, Maryland.PARTICIPANTS: A subset of 311 physically disabled, community‐dwelling women aged 65 and older whose HRV data were obtained.MEASUREMENTS: Reduced HRV was defined as the lowest quartile of each of several HRV measures exploring time and frequency domains and compared with the remaining three quartiles. Cognitive impairment was defined as a Mini‐Mental State Examination score less than 24. Multiple logistic regression was used to model the independent relationship between reduced HRV and prevalent cognitive impairment.RESULTS: The age‐, education‐, and race‐adjusted prevalence of cognitive impairment was higher in those with reduced HRV than in those with nonreduced HRV. After adjusting for relevant demographic and clinical characteristics, participants with reduced HRV were significantly more likely than those with nonreduced HRV to have cognitive impairment; these findings were consistent across different HRV indices. In particular, reduced high‐frequency power, indicative of decreased parasympathetic activity, was associated with 6.7 times greater odds of cognitive impairment (95% confidence interval=2.27–20.0).CONCLUSION: Cardiac autonomic dysfunction, particularly decreased parasympathetic activity, was independently associated with cognitive impairment in older disabled women in the community. This finding may improve understanding of the pathophysiological basis of cognitive impairment. The potential role of HRV as a cause or consequence of cognitive impairment needs to be elucidated in future studies.