bluuebunny/crossref_metadata_2025 huggingface dataset:
Progression of Chronic Hepatitis and Preneoplasia in Helicobacter hepaticus-Infected A/JCr Mice
Authors: Rogers Arlin B. , Boutin Samuel R. , Whary Mark T. , Sundina Nataliya , Zhongming Ge  , Cormier Kathleen , Fox James G.
Published: October 2004

Helicobacter hepaticus infection induces sustained inflammation and carcinoma of the liver in A/JCr mice, and serves as a model of human cancers associated with viral hepatitis and H. pylori chronic gastritis. Here we describe the pathogenesis of premalignant disease in A/JCr mice infected with H. hepaticus. We inoculated dams intragestationally and/or pups postnatally, and evaluated offspring at 3, 6, or 12 months. Mice infected at or before 3 weeks of age, but not at 12 weeks, developed disease. Male mice were most affected, but expressed a bimodal pattern of susceptibility. Males exhibited lobular necrogranulomatous and interface (chronic active) hepatitis, while females usually developed intraportal (chronic persistent) hepatitis. Portal inflammation was slowly progressive, with tertiary lymphoid nodule development by 12 months. Hepatic bacterial load and preneoplastic lesions, including clear and tigroid cell foci of cellular alteration, were correlated with lobular hepatitis severity. No extrahepatic surrogate disease marker reliably predicted individual hepatitis grade. In conclusion, gender and bacterial exposure timing are key determinants of H. hepaticus disease outcomes. Intrahepatic inflammation is driven by local signals characterized by a vigorous but nonsterilizing immune response. Continued study of chronic hepatitis progression may reveal therapeutic targets to reduce the risk of hepatocellular carcinoma.
Review: Ferruginous Bodies: Implications in the Mechanism of Fiber and Particle Toxicity
Authors: Ghio Andrew J. , Churg Andrew , Roggli Victor L.
Published: October 2004

Exposures to fibers and particles can be associated with several different lung injuries including bronchitis, bronchiolitis, pneumonitis, pleuritis, pulmonary alveolar proteinosis, pneumoconiosis, mesotheliomas, and lung cancers. The mechanism of biological effect exerted by fibers and particles has not been exactly defined. Exposures to all fibers and particles introduce a solid-liquid interface into the lower respiratory tract. These surfaces all have some concentration of oxygen-containing functional groups that demonstrate a capacity to coordinate iron. Radical generation is catalyzed by this metal resulting in a cascade of cell signaling, transcription factor activation, and mediator release. We propose that the ferruginous body (i.e., a fiber or particle with a coating of both protein and iron) provides direct evidence of a participation of iron in the biological effect of both fibers and particles. It is recommended that an identification of ferruginous bodies in the lung be regarded as support for a metal-catalyzed oxidative stress in the mechanism of cell and tissue injury.
House Rules: Institutional Choice and United States Trade Negotiations
Authors: Pahre Robert
Published: October 2004

International bargaining depends not only on the negotiators but also on the domestic political system in which they find themselves. Knowing this, countries often change domestic political institutions to influence the outcomes of international negotiations and/or to shape the domestic distributional consequences of those negotiations. This institutional change generally occurs in an already-rich institutional environment, where many different actors must jointly agree to modify existing institutions. To examine these, this paper develops a thirteen-actor model of U.S. trade policy institutions over the past century. Whereas the existing literature emphasizes the role of the median legislator in delegating to or constraining the executive, I find that changes in nonmedian procedural actors drive institutional reform in trade policy. Some of these procedural actors do not have veto authority and yet they play decisive roles, taking this analysis beyond veto player theory. The president can sometimes present these procedural actors with a choice that they can only make in a way favorable to him. As a result, small changes in the relative preferences of different nonmedian actors, such as the House Rules Committee or the key filibuster member of the Senate, can lead to large policy or institutional changes. These make a big difference in bargaining outcomes involving the United States and dramatically restrict the bargaining leeway enjoyed by negotiators.
When Do They Stop? Modeling the Termination of War
Authors: Mattes Michaela , Morgan T. Clifton
Published: October 2004

This paper deals with war termination. We develop a formal model based on the logic of domestic political accountability. We assume that leaders seek to maximize the likelihood that they will stay in office and that their decisions regarding war termination are responsive to their winning coalition's expectations and sensitivity to costs and to the costs of war. Our model generates predictions about when state leaders will prefer to terminate an ongoing war, given specific terms of settlement. By applying these results to both sides in a war, we can use the model to develop propositions regarding the terms of settlement and the duration of war given varying expectations, costs, and sensitivity to costs.
Conformal Dehn surgery and the shape of Maskit’s embedding
Authors: Parkkonen Jouni
Published: October 2004

We study the geometric limits of sequences of loxodromic cyclic groups which arise from conformal Dehn surgery. The results are applied to obtain an asymptotic description of the shape of the main cusp of the Maskit embedding of the Teichmüller space of once-punctured tori.
Cold Adaptation in Budding Yeast
Authors: Schade Babette , Jansen Gregor , Whiteway Malcolm , Entian Karl D. , Thomas David Y.
Published: October 2004

We have determined the transcriptional response of the budding yeast Saccharomyces cerevisiae to cold. Yeast cells were exposed to 10°C for different lengths of time, and DNA microarrays were used to characterize the changes in transcript abundance. Two distinct groups of transcriptionally modulated genes were identified and defined as the early cold response and the late cold response. A detailed comparison of the cold response with various environmental stress responses revealed a substantial overlap between environmental stress response genes and late cold response genes. In addition, the accumulation of the carbohydrate reserves trehalose and glycogen is induced during late cold response. These observations suggest that the environmental stress response (ESR) occurs during the late cold response. The transcriptional activators Msn2p and Msn4p are involved in the induction of genes common to many stress responses, and we show that they mediate the stress response pattern observed during the late cold response. In contrast, classical markers of the ESR were absent during the early cold response, and the transcriptional response of the early cold response genes was Msn2p/Msn4p independent. This implies that the cold-specific early response is mediated by a different and as yet uncharacterized regulatory mechanism.
Regulation of Microtubule-dependent Recycling at theTrans-Golgi Network by Rab6A and Rab6A'
Authors: Young Joanne , Stauber Tobias , del Nery Elaine , Vernos Isabelle , Pepperkok Rainer , Nilsson Tommy
Published: October 2004

The small GTPase rab6A but not the isoform rab6A' has previously been identified as a regulator of the COPI-independent recycling route that carries Golgi-resident proteins and certain toxins from the Golgi to the endoplasmic reticulum (ER). The isoform rab6A' has been implicated in Golgi-to-endosomal recycling. Because rab6A but not A', binds rabkinesin6, this motor protein is proposed to mediate COPI-independent recycling. We show here that both rab6A and rab6A' GTP-restricted mutants promote, with similar efficiency, a microtubule-dependent recycling of Golgi resident glycosylation enzymes upon overexpression. Moreover, we used small interfering RNA mediated down-regulation of rab6A and A' expression and found that reduced levels of rab6 perturbs organization of the Golgi apparatus and delays Golgi-to-ER recycling. Rab6-directed Golgi-to-ER recycling seems to require functional dynactin, as overexpression of p50/dynamitin, or a C-terminal fragment of Bicaudal-D, both known to interact with dynactin inhibit recycling. We further present evidence that rab6-mediated recycling seems to be initiated from the trans-Golgi network. Together, this suggests that a recycling pathway operates at the level of the trans-Golgi linking directly to the ER. This pathway would be the preferred route for both toxins and resident Golgi proteins.
Role of Unc104/KIF1-related Motor Proteins in Mitochondrial Transport inNeurospora crassa
Authors: Fuchs Florian , Westermann Benedikt
Published: October 2004

Eukaryotic cells use diverse cytoskeleton-dependent machineries to control inheritance and intracellular positioning of mitochondria. In particular, microtubules play a major role in mitochondrial motility in the filamentous fungus Neurospora crassa and in mammalian cells. We examined the role of two novel Unc104/KIF1-related members of the kinesin family, Nkin2 and Nkin3, in mitochondrial motility in Neurospora. The Nkin2 protein is required for mitochondrial interactions with microtubules in vitro. Mutant hyphae lacking Nkin2 show mitochondrial motility defects in vivo early after germination of conidiospores. Nkin3, a member of a unique fungal-specific subgroup of small Unc104/KIF1-related proteins, is not associated with mitochondria in wild-type cells. However, it is highly expressed and recruited to mitochondria in Δnkin-2 mutants. Mitochondria lacking Nkin2 require Nkin3 for binding to microtubules in vitro, and mitochondrial motility defects in Δnkin-2 mutants disappear with up-regulation of Nkin3 in vivo. We propose that mitochondrial transport is mediated by Nkin2 in Neurospora, and organelle motility defects in Δnkin-2 mutants are rescued by Nkin3. Apparently, a highly versatile complement of organelle motors allows the cell to efficiently respond to exogenous challenges, a process that might also account for the great variety of different mitochondrial transport systems that have evolved in eukaryotic cells.
Intracellular Mechanics of Migrating Fibroblasts
Authors: Kole Thomas P. , Tseng Yiider , Jiang Ingjye , Katz Joseph L. , Wirtz Denis
Published: October 2004

Cell migration is a highly coordinated process that occurs through the translation of biochemical signals into specific biomechanical events. The biochemical and structural properties of the proteins involved in cell motility, as well as their subcellular localization, have been studied extensively. However, how these proteins work in concert to generate the mechanical properties required to produce global motility is not well understood. Using intracellular microrheology and a fibroblast scratch-wound assay, we show that cytoskeleton reorganization produced by motility results in mechanical stiffening of both the leading lamella and the perinuclear region of motile cells. This effect is significantly more pronounced in the leading edge, suggesting that the mechanical properties of migrating fibroblasts are spatially coordinated. Disruption of the microtubule network by nocodazole treatment results in the arrest of cell migration and a loss of subcellular mechanical polarization; however, the overall mechanical properties of the cell remain mostly unchanged. Furthermore, we find that activation of Rac and Cdc42 in quiescent fibroblasts elicits mechanical behavior similar to that of migrating cells. We conclude that a polarized mechanics of the cytoskelton is essential for directed cell migration and is coordinated through microtubules.
BAF53/Arp4 Homolog Alp5 in Fission Yeast Is Required for Histone H4 Acetylation, Kinetochore-Spindle Attachment, and Gene Silencing at Centromere
Authors: Minoda Aki , Saitoh Shigeaki , Takahashi Kohta , Toda Takashi
Published: October 2004

Nuclear actin-related proteins play vital roles in transcriptional regulation; however, their biological roles remain elusive. Here, we characterize Alp5, fission yeast homolog of Arp4/BAF53. The temperature-sensitive mutant alp5-1134 contains a single amino acid substitution in the conserved C-terminal domain (S402N) and displays mitotic phenotypes, including chromosome condensation and missegregation. Alp5 forms a complex with Mst1-HAT (histone acetyltransferase). Consistently, inhibition of histone deacetylases (HDACs), by either addition of a specific inhibitor or a mutation in HDAC-encoding clr6+gene, rescues alp5-1134. Immunoblotting with specific antibodies against acetylated histones shows that Alp5 is required for histone H4 acetylation at lysines 5, 8, and 12, but not histone H3 lysines 9 or 14, and furthermore Clr6 plays an opposing role. Mitotic arrest is ascribable to activation of the Mad2/Bub1 spindle checkpoint, in which both proteins localize to the mitotic kinetochores in alp5-1134. Intriguingly, alp5-1134 displays transcriptional desilencing at the core centromere without altering the overall chromatin structure, which also is suppressed by a simultaneous mutation in clr6+. This result shows that Alp5 is essential for histone H4 acetylation, and its crucial role lies in the establishment of bipolar attachment of the kinetochore to the spindle and transcriptional silencing at the centromere.
Atypical Cardiac Myxomas
Authors: Sugeng Lissa , Sahoo Sunati , Lang Roberto M.
Published: October 2004

Atypical cardiac myxomas are a rare occurrence and may present with a variety of clinical manifestations depending on the morphology and location. We present three cases of myxomas located atypically on the left atrial appendage ridge, chordae of the mitral valve, and right atrium. Echocardiography plays a prominent role in the diagnosis and follow‐up of these patients. (ECHOCARDIOGRAPHY, Volume 21, January 2004)
Mitral Prosthetic Inflow Mimicking Severe Aortic Regurgitation
Authors: Baweja Gurpreet , Nanda Navin C. , Hans Anil K. , Liguori Chiara , Fadel Ahmad , Dod Harvinder , Ravi Barugur
Published: October 2004

We describe two patients in whom mitral valve prosthetic inflow mimicked severe aortic regurgitation. Repeat transthoracic echocardiography using multiple transducer angulations and a narrow color Doppler sector angle in one patient and a color Doppler M‐Mode study in the second patient proved useful in excluding the presence of severe aortic regurgitation. (ECHOCARDIOGRAPHY, Volume 21, January 2004)
Ambulatory Pulse Pressure, Left Ventricular Hypertrophy and Function in Arterial Hypertension
Authors: Rizzo Vito , Maio Fernando di , Petretto Federica , Marziali Marta , Bianco Gianluca , Barilla Francesco , Paravati Vincenzo , Pignata Daniele , Campbell Stefano Villatico , Donato Giuseppe , Bernardo Vincenzo , Tallarico Demetrio
Published: October 2004

Background: A wide pulse pressure (PP) can provide important risk assessment information about myocardial infarction, carotid artery atherosclerosis, and global cardiovascular risk. Ambulatory pulse pressure (APP) does not have a well‐known prognostic value in hypertensive patients. Methods: To evaluate the relationship among high APP, atrial volumes, and cardiac function, an observational study was performed on 108 untreated nonelderly hypertensive patients (mean age 54.23 ± 7.12). Twenty‐four‐hour ambulatory blood pressure monitoring, Doppler and echocardiographic measurements of systolic, diastolic function, left and right atrial volumes, left ventricular mass index and dimensions, were performed in subjects with both clinic and APP > 60 mmHg (APP1 Group). A control group of hypertensive selected subjects with both clinic and APP < 60 mmHg was chosen (APP 2 Group). Results: The APP1 group showed left atrial volume enlargement, high left ventricular mass index, and impaired diastolic function. A positive correlation was found in the APP1 group results among left ventricular end diastolic diameter (r = 0.39, P < 0.01), left atrial volume (0.38, P < 0.05), and left ventricular mass index (r = 0.33, P < 0.05); clinic PP showed a statistically significant correlation with left atrial volume, left ventricular end diastolic diameter, and left ventricular mass index only in the APP1 group. Conclusions: These results suggest that elevated APP can be considered an effective predictor of cardiovascular risk in hypertensive subjects. In these patients echocardiographic evaluation of left ventricular function and morphology can increase the prognostic value of PP. (ECHOCARDIOGRAPHY, Volume 21, January 2004)
Abnormal Diastolic Flow Demonstrated by Color M Mode Echocardiography in Hypertrophic Cardiomyopathy with Mid‐Ventricular Cavity Obliteration
Authors: Mixon Timothy A. , Giebel Dan W.
Published: October 2004

We report a case of a 55‐year‐old woman who presented with ventricular tachycardia and myocardial infarction. Investigations revealed no disease of the epicardial coronary arteries, but a diagnosis of hypertrophic cardiomyopathy with mid‐cavitary dynamic obstruction was made. Detailed echocardiographic examination, including pulse‐wave Doppler and Color M Mode recordings revealed unusual components of diastolic dysfunction. (ECHOCARDIOGRAPHY, Volume 21, January 2004)
The Influence of Ambulatory Blood Pressure Profile on Left Ventricular Geometry
Authors: Balci Bahattin , Yilmaz Ozcan , Yesildag Osman
Published: October 2004

Besides causing a hypertrophy in the left ventricle, hypertension results in a change in the geometry of the left ventricle. The blood pressure, which does not decrease enough during the night, leads to structural changes in the left ventricle. In this study, the influence of 24‐hour blood pressure profile on the left ventricular geometry was examined. Ambulatory blood pressure monitoring was applied to 60 patients with mild to moderate hypertension who had never been treated and standard echocardiographic evaluation was conducted thereafter. The patients were divided into two groups with respect to the ambulatory blood pressure profiles: the patients whose night blood pressure levels decreased by more than 10% compared to their daytime blood pressure levels (dipper) and those whose levels did not decrease that much (nondipper). The left ventricle mass index and the relative wall thickness of the patients were calculated. With respect to the left ventricle geometry, mass index and relative wall thickness of the patients were determined as: having normal geometry, concentric remodeling, eccentric hypertrophy, and concentric hypertrophy. Age, gender, systolic, and diastolic blood pressure were similar within the dipper and nondipper groups. Normal geometry, concentric remodeling, and concentric hypertrophy ratios were similar in both groups. Eccentric hypertrophy was higher in the nondipper group compared to the dipper group (42.9% vs 6.3%, P < 0.03). Patients with mild to moderate hypertension, whose blood pressure does not decrease enough, develop eccentric hypertrophy. (ECHOCARDIOGRAPHY, Volume 21, January 2004)
Abciximab Treatment for Obstructive Prosthetic Aortic and Mitral Valve Thrombosis in the Presence of Large Thrombi, Cardiogenic Shock, and Acute Evolving Embolic Stroke
Authors: Rahman Atiar M , Birnbaum Yochai , Mandava Pitchaiah , Ahmad Masood
Published: October 2004

Obstructive thrombosis of left‐sided mechanical prosthetic valves is a life‐threatening complication. Intravenous thrombolytic therapy is contraindicated due to risk of clot embolization and surgical treatment is often required for hemodynamically unstable patients. We report for the first time the successful use of abciximab in the management of a patient in cardiogenic shock with multiple prosthetic valve obstructive thrombosis and evolving embolic stroke. Serial Doppler echocardiography and cinefluoroscopy demonstrated resolution of thrombi, improvements in transvalvular gradients and improvement in leaflet motion. This observation suggests abciximab should be considered as a therapeutic option in the treatment of obstructed prosthetic heart valves. (ECHOCARDIOGRAPHY, Volume 21, January 2004)
Infected Cardiac Myxoma
Authors: Gregory Shawn A. , O'Byrne William T. , Fan Pohoey
Published: October 2004

Infected cardiac myxomas are extremely rare with only forty cases described in the literature. We report a case of an infected cardiac myxoma that presented in a manner similar to bacterial endocarditis. Our case is the first to be diagnosed using previously defined criteria, and is unusual in that transesophageal echocardiography was required to make the diagnosis. (ECHOCARDIOGRAPHY, Volume 21, January 2004)
Isolated Subclavian Artery Aneurysm: Evaluation by Transesophageal Echocardiography
Authors: Shah Alan , Katz Edward S. , Stern Alexandra , Tunick Paul A. , Kronzon Itzhak
Published: October 2004

A 50‐year‐old man was evaluated following a motor vehicle accident. Chest X‐ray showed a widened mediastinum. Transesophageal echocardiography was helpful in identifying the left subclavian artery and in demonstrating an isolated subclavian artery aneurysm. The TEE findings correlated well with the results of chest CT. Using TEE for the identification of the aortic branches in patients with chest trauma may be critical. (ECHOCARDIOGRAPHY, Volume 21, January 2004)
Clinical Applicability for the Assessment of the Valvular Mitral Stenosis Severity with Doppler Echocardiography and the Proximal Isovelocity Surface Area (PISA) Method
Authors: Lee Tao Yu , Hsu Tsui‐Lieh , Tseng Chi‐Jen , Chiao Chia‐Ding , Chiou Chuen‐Wang , Mar Guang‐Yuan , Liu Chun‐Peng , Lin Shao Lin , Chiang Hung‐Tin
Published: October 2004

Evaluation of the severity of valvular mitral stenosis and measurements of the effective rheumatic mitral valve area by noninvasive echocardiography has been well accepted. The area is measured by the two‐dimensional planimetry (PLM) method and the Doppler pressure half‐time (PHT) method. Recently, the proximal isovelocity surface area (PISA) by color Doppler technique has been used as a quantitaive measurement for valvular heart disease. However, this method needs more validation. The aim of this study was therefore to investigate the clinical applicability of the PISA method in the measurements of effective mitral valve area in patients with rheumatic valvular heart disease. Forty‐seven patients aged from 23 to 71 years, with a mean age of 53 ± 13 (25 male and 22 female, 15 with sinus rhythm, mean heart rate of 83 ± 14 beats per minute, with rheumatic valvular mitral stenosis without hemodynamically significant mitral regurgitation) were included in the study. Effective mitral valve area (MVA) derived by the PISA method was calculated as follows: 2 ×Π× (proximal aliasing color zone radius)2× aliasing velocity/peak velocity across mitral orifice. Effective mitral valve areas measured by three different methods (PLM, PHT, and PISA) were compared and correlated with those calculated by the “gold standard” invasive Gorlin's formula. The MVA derived from PHT, PLM, PISA and Gorlin's formula were 1.00 ± 0.31cm2, 0.99 ± 0.30 cm2, 0.95 ± 0.30 cm2 and 0.91 ± 0.29 cm2, respectively. The correlation coefficients (r value) between PHT, PLM, PISA, and Gorlin's formula, respectively, were 0.66 (P = 0.032, SEE = 0.64), 0.67 (P = 0.25, SEE = 0.72) and 0.80 (P = 0.002, SEE = 0.53). In conclusion, the PISA method is useful clinically in the measurement of effective mitral valve area in patients with rheumatic mitral valve stenosis. The technique is relatively simple, highly feasible and accurate when compared with the PHT, PLM, and Gorlin's formula. Therefore, this method could be a promising supplement to methods already in use. (ECHOCARDIOGRAPHY, Volume 21, January 2004)
1  ECHOCARDIOGRAPHIC FINDINGS OF REGIONAL LEFT VENTRICULAR WALL MOTION ABNORMALITIES IN ACUTE CORONARY SYNDROME AND NORMAL ANGIOGRAM
Authors: Germing A. , Lindstaedt M. , Ulrich S. , Fadgyas T. , Grewe P. , Mügge. A.
Published: October 2004

Purpose: Patients with acute coronary syndromes (ACS) should undergo early invasive diagnostic and treatment strategy according to the individual risk stratification. However, in a few cases angiography presents a normal angiogram. Echocardiography in ACS may help to assess the patients' risk and to disclose differential diagnosis in unclear cases. Few data are available on the analysis of echocardiographic findings in a patient population with ACS but normal angiogram.

Methods: A total of 51 unselected patients (72.5% male, 53.3 ± 14.5 years) were included between 1999 and 2002. All patients underwent an emergency coronary angiography due to suspected ACS but showed a normal angiogram. Patients underwent echocardiographic examination prior to invasive procedure.

Results: The preangiographic risk stratification was as follows: unstable angina (76.5%), elevated troponin T (30%), elevated creatine kinase (24%), electrocardiographic signs of ischemia (60.8%). Thirty‐one patients (60.6%) presented with a normal wall motion. The following regional wall motion abnormalities were seen: septal (n = 4, 7.8%), inferior (n = 9, 17.6%) and anterior (n = 7, 13.7%). A normal ejection fraction was detected in 40 patients (78.4%), a discrete reduction in 8 patients (15.7%), and a relevant reduction in three cases (5.9%). The invasive measurements of the ejection fraction (67 ± 14%) were without any difference to the echocardiographic measurement (68 ± 14%).

Conclusions: In spite of a normal angiogram during ACS echocardiography shows regional left ventricular wall motion abnormalities in a relevant number of patients. These findings may influence the need of further diagnostic procedures and perhaps of pharmacological treatment in those patients. Echocardiography should be added to routine diagnostic procedures in patients with ACS.
3  ISCHEMIC MITRAL VALVE REPAIR: THE IMPACT OF THE MECHANISM OF MITRAL REGURGITATION ON LATE POSTOPERATIVE RESULTS
Authors: Ereminienė E. , Vaskelyte J. , Jurkevicius R.
Published: October 2004

Aim: The aim of our study was to establish the anatomical‐functional mechanisms of ischemic mitral regurgitation (MR) and to analyse its impact on late results after mitral valve (MV) reconstructive surgery.

Methods: The study included 53 patients with ischemic MR, who underwent CABG and MV repair. MV surgery consisted of subvalvular apparatus repair and/or annuloplasty. 2D Doppler investigations performed pre‐, 10–14 days, and 12 months after surgery included evaluation of MV and left ventricular (LV) geometry and function.

Results: Analysis of the mechanisms of ischemic MR permitted dividing patients into two groups: group 1—29 patients with inferobasal scar and posterior papillary muscle (PM) displacement, including 22 patients with PM infarction and 7 patients without it, and group 2—24 patients with isolated mitral annulus (MA) dilation. In the case of PM infarction two different mechanisms of MR were stated: (a) P3 restriction and A3 prolapse due to chordal tethering, (b) A3 P3 (commissural) prolapse due to chordal papillary elongation. Preoperatively LV geometry and function were better preserved in group 1 and late MV repair results were better versus (vs.) group 2: LV end‐systolic diameter index decreased from 22.9 ± 3.1 mm/m2 to 20.9 ± 3.6 mm/m2 at 1 year, p < 0.05, LV ejection fraction increased from 34.9 ± 8.4 to 41.8 ± 8.1%, respectively, p < 0.05. No significant changes in LV geometry and function were noted in group 2.

Conclusions: The underlying mechanism of ischemic MR has an impact on MV repair results. In patients with MR due to posterobasal infarction MV repair resulted in more favorable postoperative effect‐marked improvement in LV geometry and function late after surgery versus MR due to isolated MA dilation.
5  DIAGNOSTIC PITFALLS IN THE ECHOCARDIOGRAPHIC EVALUATION OF HYPERTROPHIC OBSTRUCTIVE CARDIOMYOPATHY (HOCM) REFERRED FOR CATHETER INTERVENTIONAL THERAPY
Authors: Beer G. , Kuhn. H.
Published: October 2004

Introduction: Generally, the diagnosis of typical HOCM with subaortic obstruction and a dynamic pressure gradient across the left ventricular outflow tract is made by noninvasive diagnostic procedures with great certainty by employing transthoracic (TTE) and/or transoesophageal (TEE) echocardiography. However, in patients with asymmetric septal hypertrophy pitfalls in echocardiographic examination may arise from several additional diseases as described in casuistic reports. To date systematic investigations in patients referred for catheter interventional therapy of HOCM are lacking.

Patients and Methods: Therefore we investigated for the first time in a systematic study 200 symptomatic patients. (180 consecutive and 20 nonconsecutive patients; functional class 3 or 4 according to NYHA) with HOCM who were referred for this new catheter interventional therapy. In all patients TTE, bicycle exercise Doppler echocardiography and multiplane TEE were performed.

Results: In 4 of 180 consecutive patients. (2.2%) discrete subvalvular membranous aortic stenosis (DSAS) (3 female patients and 1 male patient; age 20 to 58 years; mean septal diameter 19 mm; Sam‐like motion in all 4 patients) was made. In all cases the diagnosis could be confirmed by surgical treatment. TEE evaluation was of crucial importance with demonstration of a typical subvalvular membrane that was situated a few millimeters below the aortic valve. In all cases a typical asymmetric septal hypertrophy mimicking HOCM was seen. Additionally, in 2 patients there was a conincidence of severe symptomatic valvular aortic stenosis and HOCM and in 1 patient a tunnel type of subvalvular aortic stenosis was present.

Conclusion: These results show the potential pitfalls in echocardiographic diagnosis of HOCM. Especially, the frequency of DSAS in symptomatic patients referred for HOCM is unexpectedly high (2.2%). Especially in patients in whom TTE is of insufficient quality, investigation employing multiplane TEE with careful evaluation of the small poststenotic subvalvular area in HOCM is of crucial importance. This is of special significance prior to catheter interventional therapy, because in these patients surgical treatment is mandatory.
A global invader at home: population structure of the green crab, Carcinus maenas, in Europe
Authors: ROMAN JOE , PALUMBI STEPHEN R.
Published: October 2004

The European green crab, Carcinus maenas, has a native distribution that extends from Norway to Mauritania. It has attracted attention because of its recent invasions of Australia, Tasmania, South Africa, Japan and both coasts of North America. To examine the population structure of this global invader in its native range, we analysed a 502‐base‐pair fragment of the mitochondrial cytochrome c oxidase I (COI) gene from 217 crabs collected in the North Atlantic and 13 specimens from the Mediterranean. A clear genetic break (11% sequence divergence) occurs between the Mediterranean and Atlantic, supporting the species‐level status of these two forms. Populations in the Faeroe Islands and Iceland were genetically distinct from continental populations (FST = 0.264–0.678), with Iceland represented by a single lineage also found in the Faeroes. This break is consistent with a deep‐water barrier to dispersal in green crabs. Although there are relatively high levels of gene flow along the Atlantic coast of Europe, slight population structure was found between the central North Sea and populations to the south. Analysis of variance, multidimensional scaling, and the distribution of private haplotypes support this break, located between Bremerhaven, Germany, and Hoek van Holland. Similar biogeographical and genetic associations for other species, such as benthic algae and freshwater eels, suggest that the marine fauna of Europe may be generally subdivided into the areas of Mediterranean, western Europe and northern Europe.
INVITED REVIEW: Plant self‐incompatibility in natural populations: a critical assessment of recent theoretical and empirical advances
Authors: CASTRIC VINCENT , VEKEMANS XAVIER
Published: October 2004

Self‐incompatibility systems in plants are genetic systems that prevent self‐fertilization in hermaphrodites through recognition and rejection of pollen expressing the same allelic specificity as that expressed in the pistils. The evolutionary properties of these self‐recognition systems have been revealed through a fascinating interplay between empirical advances and theoretical developments. In 1939, Wright suggested that the main evolutionary force driving the genetic and molecular properties of these systems was strong negative frequency‐dependent selection acting on pollination success. The empirical observation of high allelic diversity at the self‐incompatibility locus in several species, followed by the discovery of very high molecular divergence among alleles in all plant families where the locus has been identified, supported Wright's initial theoretical predictions as well as many of its later developments. In the last decade, however, advances in the molecular characterization of the incompatibility reaction and in the analysis of allelic frequencies and allelic divergence from natural populations have stimulated new theoretical investigations that challenged some important assumptions of Wright's model of gametophytic self‐incompatibility. We here review some of these recent empirical and theoretical advances that investigated: (i) the hypothesis that S‐alleles are selectively equivalent, and the evolutionary consequences of genetic interactions between alleles; (ii) the occurrence of frequency‐dependent selection in female fertility; (iii) the evolutionary genetics of self‐incompatibility systems in subdivided populations; (iv) the evolutionary implications of the self‐incompatibility locus's genetic architecture; and (v) of its interactions with the genomic environment.
Inbreeding and population structure of the potato cyst nematode (Globodera pallida) in its native area (Peru)
Authors: PICARD D. , PLANTARD O. , SCURRAH M. , MUGNIÉRY D.
Published: October 2004

The dispersal abilities and the population genetic structure of nematodes living in the soil are poorly known. In the present study, we have pursued these issues in the potato cyst nematode Globodera pallida, which parasitizes potato roots and is indigenous to South America. A hierarchical sampling regime was conducted in Peru to investigate gene flow on regional, field and plant scales. Multilocus genotypes of single individuals were obtained using eight polymorphic microsatellites markers. Large heterozygote deficiencies were observed at most loci. The limited active dispersal of larvae from their cyst, which favours mating between (half) siblings, could be responsible for this pattern. Within fields, as well as among fields within regions (even 35 km apart), low FST values suggest extensive gene flow. Among fields within regions, only 1.5–4.4% genetic variability was observed. Passive dispersal of cysts by natural means (wind, running water, or wild animals) or by anthropogenic means (tillage, movement of infected seed tubers) is probably responsible for the results observed. Among regions, high FST values were observed. Thus long‐range dispersal (more than 320 km apart) is probably limited by major biogeographical barriers such as the mountains found in the Andean Cordillera. These results provide useful information for the management of resistant varieties, to slow down the emergence and spread of resistance‐breaking pathotypes.
Major alteration of the expression site of endogenous cellulases in members of an apical termite lineage
Authors: TOKUDA GAKU , LO NATHAN , WATANABE HIROFUMI , ARAKAWA GAKU , MATSUMOTO TADAO , NODA HIROAKI
Published: October 2004

Termites are among the most important cellulose‐digesting animals on earth, and are well‐known for the symbiotic relationship they have with cellulolytic trichomonad and oxymonad flagellates (unicellular eukaryotes). Perhaps less well‐known is the fact that ∼75% of the ∼2600 described termite species — those belonging to the family Termitidae — do not harbour such flagellates. Unlike most termites from other families, the majority of termitids do not consume wood, feeding instead on soil, leaf litter, fungi, grass, or lichen. Recent years have seen the characterization of the endogenous cellulase enzymes that help termites digest cellulose, from one flagellate‐harbouring species (Reticulitermes speratus), as well as one termitid (Nasutitermes takasagoensis). The genes encoding the enzymes in these two termites are similar. However, their site of expression differs markedly — the salivary glands in R. speratus and the midgut in N. takasagoensis. To investigate this difference further, we performed a comparative study of cellulase expression in various termitid and flagellate‐harbouring species, using enzyme assays and reverse transcription polymerase chain reactions. Taxa from phylogenetically basal lineages were consistently found to express endogenous genes specifically in the salivary glands, whilst those from a relatively apical lineage containing termitids expressed cellulases solely in the midgut. Relatively low levels of cellulase activity were found in nonwood‐feeding species, while the wood‐feeding Coptotermes formosanus— arguably the most destructive pest species world‐wide — was found to have high levels of activity in all parts of the gut when compared to all other termites. In the light of these results, as well as recently accumulated phylogenetic data, we discuss scenarios for the evolution of cellulose digestion in termites.
COMMENTARY: How cryptic is the Scandinavian lynx?
Authors: PAMILO P.
Published: October 2004

A reanalysis of the existing genotypic data shows that they are compatible with the hypothesis that the present‐day Scandinavian lynx represents a recent expansion from a single source. This contradicts earlier conclusions. The difference arises when it is assumed that the expansion and colonization have been stochastic processes and that the populations may not be at a drift‐migration equilibrium.
Phylogeography of roe deer (Capreolus capreolus) populations: the effects of historical genetic subdivisions and recent nonequilibrium dynamics
Authors: RANDI E. , ALVES P. C. , CARRANZA J. , MILOŠEVIĆ‐ZLATANOVIĆ S. , SFOUGARIS A. , MUCCI N.
Published: October 2004

We sequenced 704 mitochondrial DNA (mtDNA) control‐region nucleotides and genotyped 11 autosomal microsatellites (STR) in 617 European roe deer (Capreolus capreolus) samples, aiming to infer the species’ phylogeographical structure. The mtDNA sequences were split in three distinct haplogroups, respectively, named: Clade West, sampled mainly in Iberia; Clade East, sampled mainly in Greece and in the Balkans; and Clade Central, which was widespread throughout Europe, including the eastern countries and Iberia, but not Greece. These clades might have originated in distinct Iberian and Balkanic refuges during the penultimate or the last glaciations. Clades East and West contributed little to the current postglacial mtDNA diversity in central Europe, which apparently was recolonized mainly by haplotypes belonging to Clade Central. A unique subclade within Clade Central grouped all the haplotypes sampled from populations of the Italian subspeciesC. c. italicus. In contrast, haplotypes sampled in central and southern Spain joined both Clade Central and Clade West, suggesting that subspeciesC. c. gargantahas admixed origin. STR data support a genetic distinction of peripheral populations in north Iberia and southern Italy, and show the effects of anthropogenic disturbance in fragmented populations, which were recently reintroduced or restocked and not may be in mutation–drift equilibrium. Roe deer in central Europe are mainly admixed, while peripheral populations in north Portugal, the southern Italian Apennines and Greece represent the remains of refugial populations and should be managed accordingly.
Pleistocene glaciation is implicated in the phylogeographical structure of Potamopyrgus antipodarum, a New Zealand snail
Authors: NEIMAN MAURINE , LIVELY CURTIS M.
Published: October 2004

Pleistocene glaciation has been identified as an important factor shaping present‐day patterns of phylogeographical structure in a diverse array of taxa. The purpose of this study was to use mitochondrial sequence data to address whether Pleistocene glaciation is also a major determinant of phylogeographical patterns in Potamopyrgus antipodarum, a freshwater snail native to New Zealand. We found that haplotypes were separated by no more than 3.7% sequence divergence, and major genetic divisions tended to occur on a north–south axis. These data fit the predictions of the hypothesis that isolation of P. antipodarum in glacial refugia at the northern and southern tip of the South Island of New Zealand during the Pleistocene glaciation underlies the present‐day phylogeographical structure. Because sexual P. antipodarum occasionally produce asexual offspring, we also used these data to show that the appearance of asexuality is not phylogeographically constrained. This means that the maintenance of sex in P. antipodarum cannot be wholly due to limited contact between sexual and asexual lineages and must instead be linked to a selective advantage of sexual reproduction.
Temperature‐mediated seasonal variation in phosphoglucomutase allozyme frequency in the yellow dung fly, Scathophaga stercoraria
Authors: WARD P. I. , JANN P. , BLANCKENHORN W. U.
Published: October 2004

The allozyme genetic variability of various species is correlated with a variety of morphological, physiological and fitness‐related traits. In particular, temperature can affect the fitness of insects through its influence on enzyme function. We examined the seasonal (12 days over 1 year) and daily (nine samples over each day) allozyme variation at the phosphoglucomutase (PGM) locus in one population of yellow dung flies (Scathophaga stercoraria; Diptera: Scathophagidae). PGM is of central functional importance in the mobilization of glycogen reserves for flight, and has been shown to affect larval growth at different temperatures in the laboratory. Based on a sample of over 3000 flies, we found a quadratic relationship, with a minimum at ~12 °C, between the frequency of the most common allele and temperature, primarily mediated by seasonal temperature variation. This could be caused by behavioural responses over the short‐term, but over the year either variable viability or sexual selection probably operates on this locus, maintaining the existing polymorphism. These results call for further work on the functional differences between PGM allozyme genotypes.
Phylogeography of two European Reticulitermes (Isoptera) species: the Iberian refugium
Authors: KUTNIK M. , UVA P. , BRINKWORTH L. , BAGNÈRES A.‐G.
Published: October 2004

Chemical, i.e. cuticular hydrocarbons, and molecular data were used to probe the phylogeography of Reticulitermes termites collected from various parts of France, Spain and Portugal. Phylogenetic relationships were inferred from sequences of the internal transcribed spacer (ITS2) of nuclear ribosomal RNA genes as well as from two partial mitochondrial DNA segments, the cytochrome oxidase II gene and a sequence combining the tRNA‐Leu gene and fragments of the NADH dehydrogenase I and ribosomal 16S genes. Two species, namely, R. grassei and R. banyulensis, were identified based on an analysis of cuticular hydrocarbons and the identification was confirmed by ITS2 haplotyping. However, phylogeny based on the analysis of mitochondrial DNA was not completely in agreement with the conclusions drawn from the chemical and nuclear data. An analysis of 56 R. grassei colonies revealed intraspecific differentiation into two major lineages with distinct geographical ranges. Whereas analysis of cuticular hydrocarbons showed that R. banyulensis was chemically distinct from R. grassei, analysis of mitochondrial DNA showed its close kinship with the R. grassei lineage occurring in southern Spain. This kinship could be explained by their evolution from a common polymorphic ancestor species in this ice age refugium.
Community structure of arbuscular mycorrhizal fungi in undisturbed vegetation revealed by analyses of LSU rDNA sequences
Authors: ROSENDAHL SØREN , STUKENBROCK EVA H.
Published: October 2004

Arbuscular mycorrhizal fungi (AMF) form a mutualistic symbiosis with plant roots and are found in most ecosystems. In this study the community structure of AMF in a clade of the genus Glomus was examined in undisturbed costal grassland using LSU rDNA sequences amplified from roots of Hieracium pilosella. Roots were sampled from May to November along eight 30‐m transects, 30–120 m apart. Phylogenetic analysis of the sequences revealed 11 phylogenetic clusters within the clade of Glomus. The phylogenetic clusters were patchily distributed within the area; time had no influence on the distribution pattern. The dominant cluster covered up to 10 m along the transect, whereas other clusters formed what can be interpreted as small individual mycelia. Four of the phylogenetic clusters included known species; the other clusters, including the dominant sequence types, were unknown. The dominant phylogenetic cluster enclosed nine haplotypes, and analyses of genetic diversity of this phylogenetic cluster showed that the total diversity could be found within single root fragments, suggesting that the multiple sequences were derived from a single individual.
The power and perils of ‘molecular taxonomy’: a case study of eyeless and endangered Cicurina (Araneae: Dictynidae) from Texas caves
Authors: PAQUIN P. , HEDIN M.
Published: October 2004

Rapid development in karst‐rich regions of the US state of Texas has prompted the listing of four Cicurina species (Araneae, Dictynidae) as US Federally Endangered. A major constraint in the management of these taxa is the extreme rarity of adult specimens, which are required for accurate species identification. We report a first attempt at using mitochondrial DNA (mtDNA) sequences to accurately identify immature Cicurina specimens. This identification is founded on a phylogenetic framework that is anchored by identified adult and/or topotypic specimens. Analysis of ~1 kb of cytochrome oxidase subunit I (CO1) mtDNA data for over 100 samples results in a phylogenetic tree that includes a large number of distinctive, easily recognizable, tip clades. These tip clades almost always correspond to a priori species hypotheses, and show nonoverlapping patterns of sequence divergence, making it possible to place species names on a number of immature specimens. Three cases of inconsistency between recovered tip clades and a priori species hypotheses suggest possible introgression between cave‐dwelling Cicurina, or alternatively, species synonymy. Although species determination is not possible in these instances, the inconsistencies point to areas of taxonomic ambiguity that require further study. Our molecular phylogenetic sample is largest for the Federally Endangered C. madla. These data suggest that C. madla occurs in more than twice the number of caves as previously reported, and indicate the possible synonymy of C. madla with C. vespera, which is also Federally Endangered. Network analyses reveal considerable genetic divergence and structuring across caves in this species. Although the use of DNA sequences to identify previously ‘unidentifiable’ specimens illustrates the potential power of molecular data in taxonomy, many other aspects of the same dataset speak to the necessity of a balanced taxonomic approach.