bluuebunny/crossref_metadata_2025_split huggingface dataset:
The anatomical relationships between the avian eye, orbit and sclerotic ring: implications for inferring activity patterns in extinct birds
Authors: Hall Margaret I. 
Published: May 2008

AbstractActivity pattern, or the time of day when an animal is awake and active, is highly associated with that animal's ecology. There are two principal activity patterns: diurnal, or awake during the day in a photopic, or high light level, environment; and nocturnal, awake at night in scotopic, or low light level, conditions. Nocturnal and diurnal birds exhibit characteristic eye shapes associated with their activity pattern, with nocturnal bird eyes optimized for visual sensitivity with large corneal diameters relative to their eye axial lengths, and diurnal birds optimized for visual acuity, with larger axial lengths of the eye relative to their corneal diameters. The current study had three aims: (1) to quantify the nature of the relationship between the avian eye and its associated bony anatomy, the orbit and the sclerotic ring; (2) to investigate how activity pattern is reflected in that bony anatomy; and (3) to identify how much bony anatomy is required to interpret activity pattern reliably for a bird that does not have the soft tissue available for study, specifically, for a fossil. Knowledge of extinct avian activity patterns would be useful in making palaeoecological interpretations. Here eye, orbit and sclerotic ring morphologies of 140 nocturnal and diurnal bird species are analysed in a phylogenetic context. Although there is a close relationship between the avian eye and orbit, activity pattern can only be reliably interpreted for bony‐only specimens, such as a fossil, that include both measurements of the sclerotic ring and orbit depth. Any missing data render the fossil analysis inaccurate, including fossil specimens that are flat and therefore do not have an orbit depth available. For example, activity pattern cannot be determined with confidence forArchaeopteryx lithographica, which has a complete sclerotic ring but no orbit depth measurement. Many of the bird fossils currently available that retain a good sclerotic ring tend to be flat specimens, while three‐dimensionally preserved bird fossils tend not to have a well‐preserved sclerotic ring or a well‐defined optic foramen, necessary for delimiting the orbit depth.
Rapid loss of motor nerve terminals following hypoxia–reperfusion injury occurs via mechanisms distinct from classic Wallerian degeneration
Authors: Baxter Becki , Gillingwater Thomas H. , Parson Simon H. 
Published: May 2008

AbstractMotor nerve terminals are known to be vulnerable to a wide range of pathological stimuli. To further characterize this vulnerability, we have developed a novel model system to examine the response of mouse motor nerve terminals in ex vivo nerve/muscle preparations to 2 h hypoxia followed by 2 h reperfusion. This insult induced a rapid loss of neurofilament and synaptic vesicle protein immunoreactivity at pre‐synaptic motor nerve terminals but did not appear to affect post‐synaptic endplates or muscle fibres. The severity of nerve terminal loss was dependent on the age of the mouse and muscle type: in 8–12‐week‐old mice the predominantly fast‐twitch lumbrical muscles showed an 82.5% loss, whereas the predominantly slow‐twitch muscles transversus abdominis and triangularis sterni showed a 57.8% and 27.2% loss, respectively. This was contrasted with a > 97% loss in the predominantly slow‐twitch muscles from 5–6‐week‐old mice. We have also demonstrated that nerve terminal loss occurs by a mechanism distinct from Wallerian degeneration, as the slow Wallerian degeneration (Wlds) gene did not modify the extent of nerve terminal pathology. Together, these data show that our new model of hypoxia–reperfusion injury is robust and repeatable, that it induces rapid, quantitative changes in motor nerve terminals and that it can be used to further examine the mechanisms regulating nerve terminal vulnerability in response to hypoxia–reperfusion injury.
Quantification of diverse subcellular immunohistochemical markers with clinicobiological relevancies: validation of a new computer‐assisted image analysis procedure
Authors: Lejeune Marylène , Jaén Joaquín , Pons Lluis , López Carlos , Salvadó Maria‐Teresa , Bosch Ramón , García Marcial , Escrivà Patricia , Baucells Jordi , Cugat Xavier , Álvaro Tomás 
Published: May 2008

AbstractTissue microarray technology and immunohistochemical techniques have become a routine and indispensable tool for current anatomical pathology diagnosis. However, manual quantification by eye is relatively slow and subjective, and the use of digital image analysis software to extract information of immunostained specimens is an area of ongoing research, especially when the immunohistochemical signals have different localization in the cells (nuclear, membrane, cytoplasm). To minimize critical aspects of manual quantitative data acquisition, we generated semi‐automated image‐processing steps for the quantification of individual stained cells with immunohistochemical staining of different subcellular location. The precision of these macros was evaluated in 196 digital colour images of different Hodgkin lymphoma biopsies stained for different nuclear (Ki67, p53), cytoplasmic (TIA‐1, CD68) and membrane markers (CD4, CD8, CD56, HLA‐Dr). Semi‐automated counts were compared to those obtained manually by three separate observers. Paired t‐tests demonstrated significant differences between intra‐ and inter‐observer measurements, with more substantial variability when the cellular density of the digital images was > 100 positive cells/image. Overall, variability was more pronounced for intra‐observer than for inter‐observer comparisons, especially for cytoplasmic and membrane staining patterns (P < 0.0001 and P = 0.050). The comparison between the semi‐automated and manual microscopic measurement methods indicates significantly lower variability in the results yielded by the former method. Our semi‐automated computerized method eliminates the major causes of observer variability and may be considered a valid alternative to manual microscopic quantification for diagnostic, prognostic and therapeutic purposes.
The four mammalian splice variants encoded by the p21‐activated kinase 3 gene have different biological properties
Authors: Kreis Patricia , Rousseau Véronique , Thévenot Emmanuel , Combeau Gaëlle , Barnier Jean‐Vianney 
Published: May 2008

AbstractThe p21‐activated kinases (PAK1), PAK2, and PAK3 are members of the PAK group I and share high sequence identity and common biochemical properties. PAK3 is specifically implicated in neuronal plasticity and also regulates cell cycle progression, neuronal migration, and apoptosis. Loss of function of PAK3 is responsible for X‐linked non‐syndromic mental retardation whereas gain of PAK3 function is associated with cancer. To understand the functional specificities of PAK3, we analyzed the structure of PAK3 gene products. We report here the characterization of a new alternatively spliced exon called c located upstream of the previously identified exon b. Exon b is detected in all tetrapods and not in fish, exon c is only present in mammals. Mammalian PAK3 genes encode four splice variants and the corresponding proteins were detected with specific antibodies in brain extracts. All PAK3 transcripts are specifically expressed in brain and in particular in neurons. The presence of the exons b and c renders the kinase constitutively active and decreases interaction with GTPases. The expression of the new splice variants in COS7 cells alters cell morphology and modifies the structure of focal adhesions. We propose that the appearance of new alternatively spliced exons during evolution and the resulting increase of complexity of PAK3 gene products may confer new functions to this kinase and contribute to its specific roles in neuronal signaling.
The effect of l‐arginine administration on muscle force and power in postmenopausal women
Authors: Fricke Oliver , Baecker Natalie , Heer Martina , Tutlewski Baerbel , Schoenau Eckhard 
Published: May 2008

SummaryPreviously published data (J Bone Miner Res (2005); 20: 471) did not give evidence that the administration of the nitric oxide precursor l‐arginine increases bone formation and decreases bone resorption in postmenopausal women. Data of this trial were reanalysed for putative effects of l‐arginine on muscle mass and muscular function. Therefore, 11 females of the former study group (n = 15; age 54·5 ± 4·1 years; daily oral administration of 18 g l‐arginine hydrochloride (equivalent of 14·2 g l‐arginine) over 6 months) and 12 females of the control group (n = 15; age 55·3 ± 4·4 years; daily administration of 18 g dextrose over 6 months) were analysed for biomechanical parameters (MIGF, maximal isometric grip force; PJF, peak jump force; PJP, peak jump power) and for the cross‐sectional muscle area (MA) and fat area (FA) at forearm and leg (calf) measured by peripheral quantitative computed tomography. The study was performed in a double‐blind design. The assessment of muscular and biomechanical parameters was undertaken before and after 6 months of l‐arginine versus placebo administration. l‐arginine‐supplemented females had a significant increase of PJF/kg in comparison with the control group. PJP/kg, MIGF, MA and FA were not significantly influenced by the administration of l‐arginine. In conclusion, the administration of l‐arginine increased maximal force in mechanographic analyses and may prevent a decline of muscle force in postmenopausal women.
Analysis of Headache Management in a Busy Emergency Room in the United States
Authors: Sahai‐Srivastava Soma , Desai Prakash , Zheng Ling 
Published: June 2008

Objectives.— To analyze the demographics, diagnosis, and treatment patterns in patients with headache‐seeking treatment in one of the busiest emergency rooms (ER) of an academic medical center in the USA.Background.— The past decade has seen tremendous improvement in acute and preventive management of headaches. However, there are very few data on how headache patients are managed by ER doctors.Methods.— Retrospective analysis of 100 charts chosen at random for patients with a discharge diagnosis of headache (according to ICD‐9 codes) from the University of Southern California + Los Angeles County Hospital ER.Results.— The majority of patients were female (74%) and Hispanic (76%) with an age range of 15‐68 years. The most common ER diagnoses were migraine (42%) and headache not otherwise specified (headache NOS – 42%). Fifty‐one percent of patients received a head computerized tomography; 9% received a lumbar puncture. Medications most frequently used for acute treatment, whether migraine or headache NOS, were narcotics (25%), followed by antiemetics (24%), nonsteroidal anti‐inflammatory drugs (19%), and acetaminophen (17%). Only 5% of migraine patients received migraine‐specific triptans in the ER (2% overall). Thirty‐one percent of migraineurs were given a prescription for a triptan upon discharge from the ER (17% of all patients). Eighteen percent of patients were admitted to the hospital with secondary headache. The final diagnosis in the ER matched the diagnosis of the neurologist in 79% of cases with a moderate degree of agreement.Conclusion.— Narcotics remain the medications most often chosen for treatment of all acute headaches (including migraine) in the ER. There is very little use of migraine‐specific medications in the ER. In addition, neurology consults are underutilized even in an academic setting in the ER. The data suggest a lack of clear standards of care for diagnosis and treatment of headache, especially migraines. Specific guidelines for headache management should be established keeping in mind the unique setting of the ER.
Neurogenesis in the human hippocampus and its relevance to temporal lobe epilepsies
Authors: Siebzehnrubl Florian A. , Blumcke Ingmar 
Published: June 2008

SummaryAmple evidence points to the dentate gyrus as anatomical region for persistent neurogenesis in the adult mammalian brain. This has been confirmed in a variety of animal models under physiological as well as pathophysiological conditions. Notwithstanding, similar experiments are difficult to perform in humans. Postmortem studies demonstrated persisting neurogenesis in the elderly human brain. In addition, neural precursor cells can be isolated from surgical specimens obtained from patients with intractable temporal lobe epilepsy (TLE) and propagated or differentiated into neuronal and glial lineages. It remains a controversial issue, whether epileptic seizures have an effect on or even increase hippocampal neurogenesis in humans. Recent data support the notion that seizures induce neurogenesis in young patients, whereas the capacity of neuronal recruitment and proliferation decreases with age. Animal models of TLE further indicate that these newly generated neurons integrate into epileptogenic networks and contribute to increased seizure susceptibility. However, pathomorphological disturbances within the epileptic hippocampus, such as granule cell dispersion (GCD), may not directly result from compromised neurogenesis. Still, the majority of adult TLE patients present with significant dentate granule cell loss at an end stage of the disease, which relates to severe memory and learning disabilities. In conclusion, surgical specimens obtained from TLE patients represent an important tool to study mechanisms of stem cell recruitment, proliferation and differentiation in the human brain. In addition, increasing availability of surgical specimens opens new avenues to systematically explore disease pathomechanisms in chronic epilepsies.
Homocysteine Levels and Lacunar Brain Infarcts in Elderly Women: The Prospective Population Study of Women in Gothenburg
Authors: Zylberstein Dimitri Edin , Skoog Ingmar , Björkelund Cecilia , Guo Xinxin , Hultén Bodil , Andreasson Lars‐Arne , Palmertz Bo , Thelle Dag S. , Lissner Lauren 
Published: June 2008

OBJECTIVES:To examine whether total serum homocysteine (tHcy) in a population‐based sample of middle‐aged women is an independent risk factor for presence of lacunar infarcts (LIs) 24 years later.DESIGN:Prospective population study, follow‐up time 24 years.SETTING:Gothenburg, an urban area in western Sweden.PARTICIPANTS:Five hundred twenty‐six women, 89.6% of the original study sample of the Population Study of Women in Gothenburg, aged 46 to 60 at baseline in 1968/69 and re‐examined at age 70 to 84.MEASUREMENTS:After 24 years of follow‐up, all subjects underwent a psychiatric examination, and 277 computerized tomography (CT) scans of the brain were performed. Two radiologists assessed LIs and white matter lesions (WMLs). Baseline serum tHcy was analyzed from frozen stored serum samples. Logistic regression analyses were performed controlling for potential confounders such as age and selected cardiovascular risk factors.RESULTS:Thirty‐four subjects had LIs in 1992 (12.3%). In the full multivariate‐adjusted stepwise model, LIs were associated with elevated tHcy (odds ratio (OR)=1.09, 95% confidence interval (CI)=1.01–1.17 per μmol/L of tHcy increment). Women with tHcy values in the highest tertile were almost three times as likely to have LIs (OR=2.82, 95% CI=1.34–5.93) as were those in the lowest tertile. tHcy was not related to WMLs. Subjects who did not undergo a CT scan did not differ from those who did regarding tHcy or any of the covariates studied.CONCLUSION:tHcy in middle‐aged women is an independent risk factor for LIs, but not WMLs, as observed using CT later in life.
Recurrent Falls and Dual Task–Related Decrease in Walking Speed: Is There a Relationship?
Authors: Beauchet Olivier , Annweiler Cédric , Allali Gilles , Berrut Gilles , Herrmann François R. , Dubost Véronique 
Published: May 2008

OBJECTIVES: To determine whether dual task–related changes in walking speed were associated with recurrent falls in frail older adults.DESIGN: Twelve‐month prospective cohort study.SETTING: Thirteen senior housing facilities.PARTICIPANTS: Two hundred thirteen subjects (mean age 84.4±5.5).MEASUREMENTS: Usual and dual‐tasking walking speeds (m/s) were calculated on a 10‐m straight walkway at baseline. Information on incident falls during the follow‐up year was collected monthly, and participants were divided into three groups based on the occurrence of falls (0, 1, and ≥2). Recurrent falls were defined as two or more falls during the 12‐month follow‐up period.RESULTS: Twenty subjects (9.4%) were classified as recurrent fallers. The occurrence of recurrent falls was associated with age (crude odds ratio (OR)=1.11, P=.02), number of drugs (crude OR=1.28, P=.002), and walking speed under both walking conditions (crude OR=0.96, P=.002 for usual walking and crude OR=0.60, P=.005 for walking while counting backward). Multiple Poisson regression showed that only walking speed while dual tasking and number of drugs were associated with incident falls (incident rate ratio (IRR)=0.84, P=.045 and IRR=1.10, P=.004).CONCLUSION: Slower walking speed while counting backward was associated with recurrent falls, suggesting that changes in gait performance while dual tasking might be an inexpensive way of identifying frail older adults prone to falling.
Organized Incessant Atrial Arrhythmias in the Setting of Severe, Isolated Biatrial Scarring
Authors: MASSUMI ALI , RASEKH ABDI , SAEED MOHAMMAD , FLAM SCOTT , CHEONG BENJAMIN , MOJIBIAN HAMID , RAZAVI MEHDI 
Published: May 2008

Introduction: Diffuse transmural fibrosis and scarring limited to the area without atrial dilation or significant structural heart or other systemic disease has not been reported. We present three cases of a syndrome characterized by refractory organized atrial arrhythmias, diffuse atrial scarring with electrical silence, and mechanical paralysis in the absence of atrial dilation or any systemic or neurodegenerative disorders.
Methods: Patients referred for electrophysiology study of atrial arrhythmias were included. Electroanatomic mapping with the Carto system (Biosense Webster, Diamond Bar, CA, USA) and magnetic resonance imaging (MRI) with scar sequencing were performed.
Results: There was no family or personal history of cardiac, muscular, or developmental diseases. All patients had organized atrial arrhythmias. Echocardiograms showed atrial standstill with normal atrial and ventricular dimensions. No other structural abnormalities were noted. Carto mapping revealed severe biatrial diffuse scarring. The left atrial (LA) was less affected than the right atrial (RA). MRI findings confirmed biatrial scarring. During tachycardia, islands of dissociated electrical activity could be seen in the right atria. Entrainment mapping was not performed in the atria as high‐output pacing could not capture the atria. Coronary sinus entrainment demonstrated the coronary sinus
(CS) not to be critical to the tachycardia. Ablation was targeted toward channels of low voltage but was not successful in any cases. All required atrioventricular (AV) nodal ablation with pacing.
Conclusion: An association between biatrial cardiomyopathy and scarring with normal atrial dimensions has been described. Since severe scarring has not been reported with organized arrhythmias this may represent a new syndrome.
Quality of ECG Monitoring with a Miniature ECG Recorder
Authors: JANATA ANDREAS , LEMMERT MIGUEL E. , RUSSELL JAMES K. , GEHMAN STACY , FLEISCHHACKL ROMAN , ROBAK OLIVER , PERNICKA ELISABETH , STERZ FRITZ , GORGELS ANTON P.M. 
Published: May 2008

Background: Long‐term monitoring of patients at risk of arrhythmias would benefit from a miniaturized device. This study evaluated the quality of electrocardiogram (ECG) signals recorded by a miniaturized ECG recorder.
Methods: ECG data were concurrently recorded with an investigational device (Philips Medical Systems, Seattle, WA, USA) and a Holter recorder from patients with cardiac‐related symptoms at the emergency department of a tertiary care university hospital. The device was attached in one of four locations (L1: below left clavicle, L2: midsternal, L3: below left breast, L4: left anterior axillary line in 5th intercostal space). Selected ECG strips were analyzed for atrial activity, QRS width, and basic rhythm by two physicians. Patients were divided into groups based on their number of strips (A 2–5, B 6–9, C 10–21) for descriptive presentation of the data. For statistical analyses, nonlinear mixed‐effects models were used.
Results: In 90 patients, 574 pairs of strips were analyzed. In L1 (n = 37), agreement between the device and the Holter recorder on presence of P wave was 58–80% in groups A–C and in L2 (n = 28):94–98%, L3 (n = 12):30–72%, and L4 (n = 13):0–70%; on PR interval in L1:58–80%, L2:94–98%, L3:30–62%, and L4:0–70%; on rhythm in L1:56–79%, L2:94–98%, L3:30–62%, and L4:0–70%; on QRS width in L1:86–100%, L2:88–98%, L3:100%, and L4:96–100%. The agreement of L2 in the parameters P wave, PR interval, and rhythm diagnosis was better than in the other locations (P < 0.01).
Conclusions: A miniature ECG monitor provided accurate assessment of atrial beats and rhythm diagnosis at a midsternal location and of QRS width at all locations.
Automatic Determination of Timing Intervals for Upper Limit of Vulnerability Using ICD Electrograms
Authors: SHEHATA MICHAEL , BELK PAUL , KREMERS MARK , SABA SAMIR , CAO JIAN , SWERDLOW CHARLES D 
Published: May 2008

Background: Implantable cardioverter defibrillator (ICD) implant testing based on the upper limit of vulnerability, or vulnerability testing, permits assessment of defibrillation safety margins without inducing ventricular fibrillation (VF) in most patients. Vulnerability testing requires that T‐wave shocks be timed at the most vulnerable intervals of the cardiac cycle, defined as intervals at which the strongest shock induces VF. Our goal was to develop and test an automated method to select these timing intervals using ICD intracardiac electrograms (EGMs).
Methods: At ICD implant in 22 patients, we determined the range of the most vulnerable intervals by scanning the T wave with shocks. Simultaneously, EGMs were recorded for 351 pacing sequences used for measurement of timing intervals or T‐wave shocks. EGMs were analyzed off‐line using a novel automated method to identify a stable point near the maximum slope of the T wave in the far‐field (shock) EGM. Fiducial timing points based both on the EGM and on the electrocardiogram (ECG) were used to predict the most vulnerable intervals. We compared the predicted most vulnerable to the measured most vulnerable intervals determined by T‐shock scans.
Results: Automatically determined timing points from EGMs and operator‐determined timing points from the surface ECG had comparable accuracy in identifying the measured most vulnerable intervals (91% EGM vs 86% ECG, P = NS).
Conclusions: An automated method based on ICD EGMs identifies the most vulnerable intervals with accuracy comparable to the operator‐performed, clinical method based on the surface ECG. This EGM method can be implemented efficiently in an ICD to automate vulnerability testing.