bluuebunny/crossref_metadata_2025 huggingface dataset:
Posthypoxic ventilatory decline during NREM sleep: influence of sleep apnea
Authors: Omran Amal M. , Aboubakr Salah E. , Aboussouan Loutfi S. , Pierchala Lisa , Badr M. Safwan
Published: March 2004

We wished to determine the severity of posthypoxic ventilatory decline in patients with sleep apnea relative to normal subjects during sleep. We studied 11 men with sleep apnea/hypopnea syndrome and 11 normal men during non-rapid eye movement sleep. We measured EEG, electrooculogram, arterial O2 saturation, and end-tidal Pco2. To maintain upper airway patency in patients with sleep apnea, nasal continuous positive pressure was applied at a level sufficient to eliminate apneas and hypopneas. We compared the prehypoxic control (C) with posthypoxic recovery breaths. Nadir minute ventilation in normal subjects was 6.3 ± 0.5 l/min (83.8 ± 5.7% of room air control) vs. 6.7 ± 0.9 l/min, 69.1 ± 8.5% of room air control in obstructive sleep apnea (OSA) patients; nadir minute ventilation (% of control) was lower in patients with OSA relative to normal subjects ( P < 0.05). Nadir tidal volume was 0.55 ± 0.05 liter (80.0 ± 6.6% of room air control) in OSA patients vs. 0.42 ± 0.03 liter, 86.5 ± 5.2% of room air control in normal subjects. In addition, prolongation of expiratory time (Te) occurred in the recovery period. There was a significant difference in Te prolongation between normal subjects (2.61 ± 0.3 s, 120 ± 11.2% of C) and OSA patients (5.6 ± 1.5 s, 292 ± 127.6% of C) ( P < 0.006). In conclusion, 1) posthypoxic ventilatory decline occurred after termination of hypocapnic hypoxia in normal subjects and patients with sleep apnea and manifested as decreased tidal volume and prolongation of Te; and 2) posthypoxic ventilatory prolongation of Te was more pronounced in patients with sleep apnea relative to normal subjects.
Effects of tilting and volume loading on plasma levels and urinary excretion of relaxin, NT-pro-ANP, and NT-pro-BNP in male volunteers
Authors: Heringlake Matthias , Heide Carsten , Bahlmann Ludger , Eichler Wolfgang , Pagel Horst , Schmucker Peter , Wergeland Ragnhild , Armbruster Franz Paul , Klaus Stephan
Published: March 2004

The polypeptide relaxin (RLX) has been suggested to play a role in cardiorenal integration and to be related to the natriuretic peptide system. We hence examined the effects of variations in thoracic blood volume and intravenous volume loading on plasma and urinary RLX levels and associated changes in natriuretic peptide levels in healthy men. Two groups of eight subjects were randomly tilted into a 15° feet-down or a 15° head-down position. Ten volunteers were crossover subjected to an infusion of 15 ml/kg of 0.9% NaCl (over 60 min) or control during an observation period of 10 h. Blood and urine were sampled at timed intervals. RLX, NH2-terminal prohormones of atrial natriuretic peptide (NT-pro-ANP), and NH2-terminal prohormones of brain natriuretic peptide (NT-pro-BNP) were determined by enzyme, radio-, and electrochemoluminescence immunoassays, respectively. NT-pro-ANP levels (in percentage of baseline levels) were higher ( P < 0.05) during the head-down (124 ± 13%) than during the feet-down position (82 ± 6%). NT-pro-BNP and RLX were not affected by tilting. Volume loading induced a short-lasting increase in plasma NT-pro-ANP, a delayed increase in plasma NT-pro-BNP, had no effect on plasma RLX, and induced a parallel increase in urine flow, renal excretion of sodium, RLX, and NT-pro-BNP. It is concluded that variations in thoracic blood volume in healthy men are not associated with variations in plasma RLX. Increased urinary RLX and NT-pro-BNP excretion during volume loading suggest renal production and a possible role of kidney-derived RLX and brain natriuretic peptide in sodium homeostasis in men.
Statocyst Hair Cell Activation of Identified Interneurons and Foot Contraction Motor Neurons in Hermissenda
Authors: Crow Terry , Tian Lian-Ming
Published: March 2004

Pavlovian conditioning of Hermissenda produces both light-elicited inhibition of normal positive phototactic behavior and conditioned stimulus (CS)-elicited foot-shortening. Rotation, the unconditioned stimulus (US) elicits foot-shortening and reduced forward ciliary locomotion. The neural circuit supporting ciliary locomotion and its modulation by light is known in some detail. However, the neural circuits responsible for rotation-elicited foot-shortening and reduced forward ciliary locomotion are not known. Here we describe components of the neural circuit in Hermissenda that produce anterior foot contraction and ciliary activation mediated by statocyst hair cells. We have characterized in semi-intact preparations newly identified pedal ventral contraction motor neurons (VCMNs) and interneurons (Ib). Type Ib interneurons receive polysynaptic input from statocyst hair cells and project directly to VCMNs and cilia-activating motor neurons. Depolarization of VCMNs with extrinsic current in normal artificial seawater (ASW) and high-divalent cation ASW, and under conditions where central synaptic transmission was suppressed with 5 mM Ni2+ ASW, elicited a contraction of the ipsilateral anterior foot measured from videotape recordings. Mechanical displacement of the statocyst or depolarization of identified statocyst hair cells with extrinsic current elicited spikes and complex excitatory postsynaptic potentials (EPSPs) in type Ib interneurons and complex EPSPs and spikes recorded in VCMNs. Type Ib interneurons are electrically coupled and project to VCMNs and VP1 cilia-activating motor neurons located in the contralateral pedal ganglia. The results indicate that statocyst hair-cell-mediated anterior foot contraction and graviceptive ciliary locomotion involve different interneuronal circuit components from the circuit previously identified as supporting light modulated ciliary locomotion.
Alcohol Activates a Sucrose-Responsive Gustatory Neural Pathway
Authors: Lemon Christian H. , Brasser Susan M. , Smith David V.
Published: March 2004

A strong positive association exists between the ingestion of alcohol and sweet-tasting solutions. The neural mechanisms underlying this relationship are unknown, although recent data suggest that gustatory substrates are involved. Here, we examined the role of sweet taste receptors and central neural circuits for sugar taste in the gustatory processing of ethanol. Taste responses to ethanol (3, 5, 10, 15, 25, and 40% vol/vol) and stimuli of different taste qualities (e.g., sucrose, NaCl, HCl, and quinine-HCl) were recorded from neurons of the nucleus of the solitary tract in anesthetized rats prior to and after oral application of the sweet receptor blocker gurmarin. The magnitude of ethanol-evoked activity was compared between sucrose-responsive ( n = 21) and sucrose-unresponsive ( n = 20) neurons and the central neural representation of ethanol taste was explored using multivariate analysis. Ethanol produced robust concentration-dependent responses in sucrose-responsive neurons that were dramatically larger than those in sucrose-unresponsive cells. Gurmarin selectively and similarly inhibited ethanol and sucrose responses, leaving NaCl, HCl, and quinine responses unaltered. Across-neuron patterns of response to ethanol were most similar to those evoked by sucrose, becoming increasingly more so as the ethanol concentration was raised. Results implicate taste receptors for sucrose as candidate receptors for ethanol and reveal that alcohol and sugar taste are represented similarly by gustatory activity in the CNS. These findings have important implications for the sensory and reward properties of alcohol.
Reciprocal Modulation of Calcium Dynamics at Rod and Cone Photoreceptor Synapses by Nitric Oxide
Authors: Kourennyi Dmitri E. , Liu Xiao-dong , Hart Jason , Mahmud Farid , Baldridge William H. , Barnes Steven
Published: March 2004

The abundance of nitric oxide (NO) synthesizing enzymes identified in the vertebrate retina highlight the importance of NO as a signaling molecule in this tissue. Here we describe opposing actions of NO on the rod and cone photoreceptor synapse. Depolarization-induced increases of calcium concentration in rods and cones were enhanced and inhibited, respectively, by the NO donor S-nitrosocysteine. NO suppressed calcium current in cones by decreasing the maximum conductance, whereas NO facilitated rod Ca channel activation. NO also activated a nonselective voltage-independent conductance in both rods and cones. Suppression of NO production in the intact retina with NG-nitro-l-arginine favored cone over rod driven postsynaptic signals, as would be expected if NO enhanced rod and suppressed cone synaptic activity. These findings may imply involvement of NO in regulating the strength of rod and cone pathways in the retina during different states of adaptation.
Cycle-to-Cycle Variability of Neuromuscular Activity inAplysiaFeeding Behavior
Authors: Horn Charles C. , Zhurov Yuriy , Orekhova Irina V. , Proekt Alex , Kupfermann Irving , Weiss Klaudiusz R. , Brezina Vladimir
Published: March 2004

Aplysia consummatory feeding behavior, a rhythmic cycling of biting, swallowing, and rejection movements, is often said to be stereotyped. Yet closer examination shows that cycles of the behavior are very variable. Here we have quantified and analyzed the variability at several complementary levels in the neuromuscular system. In reduced preparations, we recorded the motor programs produced by the central pattern generator, firing of the motor neurons B15 and B16, and contractions of the accessory radula closer (ARC) muscle while repetitive programs were elicited by stimulation of the esophageal nerve. In other similar experiments, we recorded firing of motor neuron B48 and contractions of the radula opener muscle. In intact animals, we implanted electrodes to record nerve or ARC muscle activity while the animals swallowed controlled strips of seaweed or fed freely. In all cases, we found large variability in all parameters examined. Some of this variability reflected systematic, slow, history-dependent changes in the character of the central motor programs. Even when these trends were factored out, however, by focusing only on the differences between successive cycles, considerable variability remained. This variability was apparently random. Nevertheless, it too was the product of central history dependency because regularizing merely the high-level timing of the programs also regularized many of the downstream neuromuscular parameters. Central motor program variability thus appears directly in the behavior. With regard to the production of functional behavior in any one cycle, the large variability may indicate broad tolerances in the operation of the neuromuscular system. Alternatively, some cycles of the behavior may be dysfunctional. Overall, the variability may be part of an optimal strategy of trial, error, and stabilization that the CNS adopts in an uncertain environment.
Flavoprotein Autofluorescence Imaging of Neuronal Activation in the Cerebellar Cortex In Vivo
Authors: Reinert Kenneth C. , Dunbar Robert L. , Gao Wangcai , Chen Gang , Ebner Timothy J.
Published: March 2004

Autofluorescence has been used as an indirect measure of neuronal activity in isolated cell cultures and brain slices, but only to a limited extent in vivo. Intrinsic fluorescence signals reflect the coupling between neuronal activity and mitochondrial metabolism, and are caused by the oxidation/reduction of flavoproteins or nicotinamide adenine dinucleotide (NADH). The present study evaluated the existence and properties of these autofluorescence signals in the cerebellar cortex of the ketamine/xylazine anesthetized mouse in vivo. Surface stimulation of the unstained cerebellar cortex evoked a narrow, transverse beam of optical activity consisting of a large amplitude, short latency increase in fluorescence followed by a longer duration decrease. The optimal wavelengths for this autofluorescence signal were 420–490 nm for excitation and 515–570 nm for emission, consistent with a flavoprotein origin. The amplitude of the optical signal was linearly related to stimulation amplitude and frequency, and its duration was linearly related to the duration of stimulation. Blocking synaptic transmission demonstrated that a majority of the autofluorescence signal is attributed to activating the postsynaptic targets of the parallel fibers. Hypothesized to be the result of oxidation and subsequent reduction of flavoproteins, blocking mitochondrial respiration with sodium cyanide or inactivation of flavoproteins with diphenyleneiodonium substantially reduced the optical signal. This reduction in the autofluorescence signal was accomplished without altering the presynaptic and postsynaptic components of the electrophysiological response. Results from reflectance imaging and blocking nitric oxide synthase demonstrated that the epifluorescence signal is not the result of changes in hemoglobin oxygenation or blood flow. This flavoprotein autofluorescence signal thus provides a powerful tool to monitor neuronal activity in vivo and its relationship to mitochondrial metabolism.
The expression of native and cultured RPE grown on different matrices
Authors: Tian Jane , Ishibashi Kazuki , Handa James T.
Published: March 2004

The purpose of this work was to determine the expression profiles of retinal pigment epithelial (RPE) cells grown on different matrices and to assess the degree of culture-induced artifact by comparing the profiles to native RPE. Visually confluent ARPE-19 cells were grown on plastic, Matrigel, collagen I, collagen IV, laminin, and fibronectin for 1 wk, and serum was withdrawn for 3 days. Morphologically normal, macular RPE cells were laser-capture microdissected from three human eye globes. Total RNA was extracted from 5,000 cells and reverse transcribed, and radiolabeled cDNA probes were hybridized to an array containing 4,325 known genes. Arrays were assessed by cluster analysis and significance analysis of microarrays (SAM). Real-time RT-PCR was used to validate differentially expressed genes. Despite similar morphology, ARPE-19 demonstrated different expression profiles when grown on different matrices. Cluster analysis showed that cells grown on collagen IV, laminin, and fibronectin had similar profiles that were distinct from cells grown on collagen I. Cells grown on plastic clustered closest to native RPE. This expression pattern was confirmed with supervised cluster analyses. The number of differentially expressed genes, function of differentially expressed genes, and profile of expressed and unexpressed genes suggest that the overall expression profile of cultured cells is significantly different from native RPE. RPE cells grown on collagen IV, laminin, and fibronectin have profiles more similar than cells grown on plastic, Matrigel, or collagen I. The overall mRNA phenotype, however, is different from morphologically normal, native macular RPE.
Thermally-induced stresses in thin aluminum layers grown on silicon
Authors: Eiper E. , Resel R. , Eisenmenger-Sittner C. , Hafok M. , Keckes J.
Published: March 2004

Elevated-temperature X-ray diffraction (XRD) was used to evaluate residual stresses in aluminum thin films on Si(100). The films with a thickness of 2 μm were deposited by magnetron sputtering at different temperatures, and XRD measurements were carried out with the heating stage DHS 900 mounted on a Seifert 3000 PTS diffractometer. The strains were characterized always in temperature cycles from room temperature up to 450 °C with steps of 50 °C. Stress values in weakly textured thin films were calculated using the Hill model, applying temperature-dependent X-ray elastic constants of aluminum. The thin films exhibit specific temperature hysteresis of stresses depending on the deposition temperature (being from the range of 50 °C–300 °C). The results allow us to quantify contributions of intrinsic and extrinsic stresses to the total stress in the layers as well as to evaluate phenomena related to plastic yield. The comparison of the data from thin films deposited at different temperatures indicate a dependence of intrinsic stresses on the substrate temperature during deposition as well as the presence of the plastic yield in films during the cool-down after deposition
Advances in quantitative XRD analysis for clinker, cements, and cementitious additions
Authors: Walenta G. , Füllmann T.
Published: March 2004

The Rietveld method allows a precise quantitative phase analysis of building materials. Thanks to the development of stable-functioning software and the use of high-performance detectors, a quantitative phase analysis by X-ray, including sample preparation, and measurement and evaluation, can be performed in fewer than ten minutes. This has made it possible to integrate the method into existing laboratory automation systems for process and quality control to provide a means of online monitoring. Due to the completely automated operating principle of the Rietveld software, no additional staff is required and the results are user-independent. The Rietveld method is now being employed in industrial laboratories and also in various cement plants owned by the Lafarge Group as the standard method of quantitative analysis of Portland Cement clinkers and Portland Cements (CEM I, CEM II A-L).
Texture measurements using the new neutron diffractometer HIPPO and their analysis using the Rietveld method
Authors: Vogel Sven C. , Hartig Christian , Lutterotti Luca , Von Dreele Robert B. , Wenk Hans-Rudolf , Williams Darrick J.
Published: March 2004

In this paper we describe the capabilities for texture measurements of the new neutron time-of-flight diffractometer HIPPO at the Los Alamos Neutron Science Center. The orientation distribution function (ODF) is extracted from multiple neutron time-of-flight histograms using the full-pattern analysis first described by Rietveld. Both, the well-established description of the ODF using spherical harmonics functions and the WIMV method, more recently introduced for the analysis of time-of-flight data, are available to routinely derive the ODF from HIPPO data. At ambient conditions, total count time of less than one hour is ample to collect sufficient data for texture analysis in most cases. The large sample throughput for texture measurements at ambient conditions possible with HIPPO requires a robust and reliable, semi-automated data analysis. HIPPO’s unique capabilities to measure large quantities of ambient condition samples and to measure texture at temperature and uni-axial stress are described. Examples for all types of texture measurements are given
X-rays in art and archaeology: An overview
Authors: Schreiner M. , Frühmann B. , Jembrih-Simbürger D. , Linke R.
Published: March 2004

An overview of the techniques used in art and archaeology is presented and the applicability of X-ray radiography, X-ray fluorescence (XRF), and X-ray diffraction analysis (XRD) as a tool for nondestructive investigations of objects of art and archaeology is discussed. X-ray radiography, for example, is a standard technique widely used and accepted by art historians, archaeologists, curators, and conservators as this method enables information about the manufacturing process and the condition of an object without “touching” the artifact. XRF and XRD enable a nondestructive determination of the material composition of artifacts and the determination of the crystalline structure of the components too. Air path systems and instruments with the micro-beam of X-ray and synchrotron radiation were applied for the analysis of easel paintings, pigments in paint layers, glass artifacts, and coins.
Modulation of Drug Transporters at the Blood-Brain Barrier
Authors: Fricker Gert , Miller David S.
Published: March 2004

A major challenge in the management of diseases of the central nervous system is the limited penetration of drugs into the brain. The structures responsible are the capillaries of the brain, whose endothelial cells form the so-called blood-brain barrier. Understanding the cellular and molecular structure as well as integrated function of this barrier is a prerequisite for successful drug delivery to the brain. Here we briefly review current knowledge about the active transport proteins (ABC and organic anion transporters) which function at the blood-brain barrier. We describe novel approaches to (1) modulate carrier protein function, and (2) circumvent the transporter-based carrier by targeted site-specific drug delivery systems, such as immunoliposome and nanoparticulate systems.
Inhibitory Effects of J78, a Newly Synthesized 1,4-Naphthoquinone Derivative, on Experimental Thrombosis and Platelet Aggregation
Authors: Jin Yong-Ri , Ryu Chung-Kyu , Moon Chang-Kiu , Cho Mi-Ra , Yun Yeo-Pyo
Published: March 2004

Several compounds with the backbone of 1,4-naphthoquinone chemical structure have been reported to display antiplatelet and antithrombotic activities, indicating that this congener compound may be a new source in the antithrombotic drug development. In the present study, the possible antiplatelet activity and antithrombotic efficacy of J78 (2-chloro-3-[2′-bromo, 4′-fluoro- phenyl]-amino-8-hydroxy-1,4-naphthoquinone), a newly synthesized 1,4-naphthoquinone derivative, were examined. Orally administered J78 (50, 100 mg/kg) dose dependently protected mice against the collagen + epinephrine-induced thromboembolic death. Orally administered J78 also significantly inhibited the ADP- and collagen-induced rat platelet aggregation ex vivo, with inhibition values of 44 and 40%, respectively. J78 inhibited the collagen-, arachidonic acid- and thrombin-induced human platelet aggregation concentration dependently in vitro, with IC50 values of 7.8 ± 0.4, 10.1 ± 0.4 and 18.4 ± 2.0 µmol/l, respectively. It was also active in inhibiting Ca2+ ionophore, A23187-induced platelet aggregation, suggesting that J78 may have an inhibitory effect on Ca2+ mobilization. J78, however, did not alter coagulation parameters such as activated partial thromboplastin time and prothrombin time in human plasma. Taken together, these results suggest that J78 may be a promising antithrombotic agent, and its antithrombotic activity may be due to antiplatelet rather than anticoagulation activity.
Subjective Effects of Slow-Release Bupropion versus Caffeine as Determined in a Quasi-Naturalistic Setting
Authors: Zernig Gerald , De Wit Harriet , Telser Stefan , Nienhusmeier Matthias , Wakonigg Gudrun , Sturm Katja , Berger Iris , Kemmler Georg , Saria Alois
Published: March 2004

Bupropion (BUP), which in its slow-release formulation (Zyban®) is used as a smoking-cessation drug, increases dopamine overflow in the nucleus accumbens and serves as a reinforcer in animal experiments, both suggesting that BUP may possess some abuse liability. The present study examined if BUP produced subjective effects indicative of abuse liability in a quasi-naturalistic setting, with caffeine (CAF) serving as a positive control. In a randomized double-blind crossover design, male smokers (n = 50) ingested two doses (interdosing interval, 6 h) of placebo (PLC), 178 mg CAF, or 150 mg slow-release BUP in their normal mid-week work environment. They completed questionnaires administered by telephone at regular intervals. CAF significantly increased ratings of ‘pleasant effects’ (p = 0.008) and ‘high’ (p = 0.03), whereas BUP produced a ‘high’ of only very moderate size (p = 0.02). In 3 subjects each, BUP or CAF produced ratings of ‘pleasant effects’ that were >9-fold higher than those for PLC. Finally, BUP increased the number of cigarettes smoked by 29% (i.e., from 24 to 31 per day; p = 0.004) only in those subjects who were unable to report any effect of either BUP or CAF. CAF had no effect on cigarette consumption. These findings suggest that BUP, like CAF, might be of some abuse liability in a small subgroup of smokers (i.e., 6% each of the present sample), and it may transiently increase, rather than decrease, smoking during early phases of treatment in continuing smokers.
Aortic Valve Replacement in Patients with Severely Reduced Left Ventricular Function
Authors: Paul Subroto , Mihaljevic Tomislav , Rawn James D. , Cohn Lawrence H. , Byrne John G.
Published: March 2004

Aortic valve replacement (AVR) can be done safely in patients with severe aortic stenosis (AS) and depressed ventricular function (ejection fraction ≤35%). Dobutamine echocardiography is useful to identify AS patients with contractile reserve who will benefit from AVR and can be used for risk stratification of these patients. AVR can also be undertaken in patients with severe aortic regurgitation and depressed ventricular function with an acceptable operative mortality. AVR in both groups results in a 5-year survival of approximately 70%, which is similar to that of orthotopic heart transplantation. Due to the comorbidities of immunosuppression and limited donor organ supply, AVR should be attempted prior to transplantation in both these high-risk groups.
Mitral Valve Surgery in Patients with Ischemic and Nonischemic Dilated Cardiomyopathy
Authors: Geha Alexander S. , El-Zein Chawki , Massad Malek G.
Published: March 2004

Congestive heart failure (CHF) is a chronic, progressive disease and its central element is the remodeling of the cardiac chamber associated with ventricular dilatation. Secondary mitral regurgitation is a complication of end-stage cardiomyopathy and is associated with a poor prognosis. It is due to progressive mitral annular dilatation and alteration in the geometry of the left ventricle. A vicious cycle of continuing volume overload, ventricular dilatation, progression of annular dilatation, increased left ventricular wall tension and worsening mitral regurgitation and CHF occurs. The mainstays of medical therapy are diuretics and afterload reduction, which are associated with poor long-term survival in these patients. Historically, the surgical approach to patients with mitral regurgitation was mitral valve replacement, but these patients were not considered operative candidates because of their high morbidity and mortality. Heart transplantation is now considered standard treatment for select patients with end-stage heart disease; however, it is applicable only to a small number of patients. Mitral valve replacement in these patients is associated with adverse consequences on left ventricular systolic function resulting from interruption of the annulus-papillary muscle continuity. Preserving the mitral valve apparatus and left ventricle in mitral valve repair enhances and maintains left ventricular function and geometry with an associated decrease in wall stress. Using these operative techniques to alter the shape of the left ventricle, in combination with optimal medical management for heart failure, improves survival and may avoid or postpone transplantation.
Revascularization Options for Ischemic Cardiomyopathy: On-Pump and Off-Pump Coronary Artery Bypass Surgery
Authors: Khabbaz Kamal R. , DeNofrio David , Kazimi Marwan , Carpino Philip A.
Published: March 2004

Patients with ischemic cardiomyopathy and markedly reduced left ventricular (LV) function should be evaluated for coronary artery bypass surgery (CABG) before other surgical options are considered. The success of surgery depends on the presence of viable myocardium and target coronary arteries of acceptable quality. Long-term survival in this setting may be comparable to that with cardiac transplantation. Off-pump CABG can be safely and reproducibly performed in patients with diminished LV function. Off-pump beating heart surgery may provide additional benefits to these patients by reducing some of the complications that are associated with cardiopulmonary bypass.
Mechanisms and Results of Transmyocardial Laser Revascularization
Authors: Horvath Keith A.
Published: March 2004

Transmyocardial laser revascularization (TMR) is a technique that has been performed on over 10,000 patients around the world. Most of the patients were not suffering from heart failure. TMR is principally used for the treatment of angina, but in patients with significant reversible ischemia that is not amenable to conventional therapy, TMR may also improve myocardial function. The results of using TMR as a treatment for angina show a dramatic improvement in symptoms and quality of life. This paper reviews the current status of TMR techniques, mechanisms and results.
Ventricular Reconstruction Surgery for Congestive Heart Failure
Authors: Lee Richard , Hoercher Katherine J. , McCarthy Patrick M.
Published: March 2004

The significant increase in the prevalence of heart failure in the United States has made this disease a major health problem. The continued shortage of donor organs has prevented heart transplantation from becoming an effective solution for the treatment of end-stage heart failure, and as a result, surgical treatments for heart failure have been reexamined. Surgical therapies represent the evolution of conventional operations, such as coronary artery bypass surgery, and the application of the more novel left ventricular (LV) reconstruction operations which address the geometry of the LV, the important component in the failing heart.
Ventricular Assist Devices as a Bridge to Transplant or Recovery
Authors: Kherani Aftab R. , Maybaum Simon , Oz Mehmet C.
Published: March 2004

Ventricular assist devices have emerged as the standard of care in treating end-stage heart failure. Their success in bridging patients to transplantation is well documented. The data supporting their ability to bridge patients to recovery is sparser. However, as technology continues to advance, these devices will offer a high quality of life both in and out of the hospital setting, making them options for a broader spectrum of heart failure patients.
Use of the Flowmaker (Jarvik 2000) Left Ventricular Assist Device for Destination Therapy and Bridging to Transplantation
Authors: Frazier O.H. , Shah Nyma A. , Myers Timothy J. , Robertson Kimberly D. , Gregoric Igor D. , Delgado Reynolds
Published: March 2004

The Flowmaker left ventricular assist device (formerly known as the Jarvik 2000) is an axial-flow pump that provides continuous flow from the left ventricle to the aorta. Designed for either temporary or permanent use, the Flowmaker is undergoing clinical trials in the United States and Europe. The goal of this therapy is to provide adequate circulatory flow while partially reducing the left ventricular size and end-diastolic pressure. This gives the native ventricle an opportunity to remodel itself. Those who benefit the most from this technology are patients who require only true left ventricular assistance rather than total capture of the left ventricular output. Because of the Flowmaker’s simplicity and safety of implantation, as well as the absence of late pump failure, its use may be justified in severely impaired class III and IV (but not preterminal) heart failure patients.
Genetics and Gene Manipulation Therapy of Premature Coronary Artery Disease
Authors: Chaer Rabih A. , Billeh Rana , Massad Malek G.
Published: March 2004

Despite the notable recent scientific advances, our ability to detect and prevent premature coronary artery disease (CAD) remains limited, and the identification of patients at risk is yet to be based on objective scientific testing. Eliciting a family history of CAD currently remains the only available screening tool to identify patients with a genetic predisposition. The risk of CAD attributable to genes appears to be most significant at younger ages, and this may explain the lack of definite markers for the disease. Candidate gene association studies focusing on young patients with CAD will, therefore, be more likely to identify a true genetic risk. In this report, we review the known genetic risk factors for premature CAD. We also discuss the potential gene manipulation therapy of CAD as well as of vein graft atherosclerosis following coronary artery bypass surgery.
Therapeutic Angiogenesis: A Biologic Bypass
Authors: Syed Imran S. , Sanborn Timothy A. , Rosengart Todd K.
Published: March 2004

The use of angiogenic factors to effect therapeutic angiogenesis may be an attractive treatment modality for a substantial number of patients who have diffuse coronary artery disease and who are not candidates for traditional revascularization procedures. Delivery of angiogenic factors as a protein or gene encoding for the respective protein product has been shown to induce angiogenesis in numerous animal models, and expression of a functioning product has been demonstrated. Various early clinical trials of therapeutic angiogenesis have shown reduction in anginal symptoms and increases in exercise time, as well as objective evidence of improved perfusion, left ventricular function and angiographic appearance following such angiogenic treatments.
Hyperbaric Oxygen in the Treatment of Sudden Hearing Loss
Authors: Racic Goran , Maslovara Sinisa , Roje Zeljka , Dogas Zoran , Tafra Robert
Published: March 2004

Treatment of idiopathic sudden hearing loss (SHL) is still a great problem for the physicians, due to the still unexplained etiopathogenesis of the disease. This retrospective study includes 115 patients with idiopathic SHL and compares two therapy regimens. Of the total number of patients, 51 had been primarily treated by hyperbaric oxygen (HBO) at 2.8 bar. The remaining 64 patients had been treated by pentoxifylline infusions in increasing and decreasing doses. Hearing thresholds were ascertained at the frequencies of 250, 500, 1,000, 2,000 and 4,000 Hz using pure-tone audiometry. The results after treatment showed a statistically significant improvement of hearing by 46.35 (SD ±18.58) dB hearing level (HL) in the group of patients treated with HBO, compared with an improvement of hearing by 21.48 dB HL (SD ±13.5) in the group of patients treated with pentoxifylline infusions (p < 0.001). Furthermore, hearing recovered to physiological values in 24 of 51 (47.1%) HBO-treated patients, compared to only 4 of 64 (6.2%) of the pentoxifylline-treated patients. Furthermore, after pentoxifylline treatment only 8/64 (12.5%) patients showed partial recovery, whereas after HBO therapy 21/51 (41.2%) patients improved up to a mild persistent hearing loss. This indicates strong evidence that HBO therapy is more effective in the treatment of idiopathic SHL than conventional rheological treatment. However, more prospective clinical trials should confirm the efficiency of HBO therapy and lead to its wider application.
Primary Lymphoma of the Larynx: New Diagnostic and Therapeutic Approaches
Authors: Nayak Jayakar V. , Cook James R. , Molina J. Thomas , Branch Matthew P. , Branstetter IV Barton F. , Ferris Robert L. , Myers Eugene N.
Published: March 2004

Tumors primary in the larynx, when not of squamous cell origin, require special diagnostic and therapeutic attention. An unexpected case of non-Hodgkin’s lymphoma localized in the larynx in a patient with a brief history of dysphagia and hoarseness is discussed. This supraglottic tumor was extensively characterized at our institution for morphologic features by microlaryngoscopy, histology, immunocytochemical profiles with flow cytometry, chromosomal aberrations using banded karyotyping and extent of disease via PET-CT imaging. Our detailed analysis distinguished this neoplasm as a new-onset diffuse large B cell laryngeal lymphoma rather than a mucosa-associated lymphoid tissue lymphoma. A rational diagnostic approach guided the combination chemotherapy/immunotherapy treatment strategy instead of traditional localized radiation therapy. These findings highlight the importance of a thorough phenotypic and cytogenetic characterization of head and neck neoplasms, which has implications for downstream diagnostic considerations, interventional strategies and the available therapeutic options. The presence of nonsquamous laryngeal tumors reinforces the dictum to obtain a reliable tissue diagnosis before initiating definitive therapy.
Expression of Basigin, a Member of the Immunoglobulin Superfamily, in the Mouse Cochlea
Authors: Kawano Hirokazu , Tono Tetsuya , Kadomatsu Kenji , Muramatsu Takashi , Komune Shizuo
Published: March 2004

To elucidate the function of basigin (Bsg) in the mouse cochlea, its expression was investigated by reverse-transcription polymerase chain reaction (RT-PCR) and immunohistochemical staining. Amplification by RT-PCR of Bsg-specific primer pairs in total RNA extracted from the mouse cochlea revealed chain reaction products of the expected sizes. Sequence analysis confirmed that the product sequences were identical to sequences in known Bsg fragments. Although Bsg was negative in the capillaries within the cochlea, positive Bsg immunoreactivity was found in the capillaries of the auditory nerve and in the basal cells of the stria vascularis. These findings suggest that Bsg may play an important role in the maintenance of homeostasis, not only of the neural environment in the auditory nerve but also of cochlear fluid.
Basaloid Squamous Cell Carcinoma of the Hypopharynx
Authors: Zbären Peter , Nuyens Michel , Stauffer Edouard
Published: March 2004

In a retrospective study, clinical, histopathological and immunohistochemical findings of basaloid squamous cell carcinoma (BSCC) of the hypopharynx are analyzed and compared with the literature. Among 196 patients treated for hypopharyngeal carcinoma between January 1993 and December 2000, 6 patients fulfilled the morphological and immunohistochemical criteria of a BSCC. Three primary tumors were initially classified as T3 and 3 as T1, 3 presented with lymph node metastases. In no case was the BSCC associated with another primary neoplasm. Two patients developed distant metastases during the follow-up and died from the disease at 26 and 35 months. Four patients are alive with no evidence of disease at 27, 29, 61 and 87 months. We observed a contrast in the clinical behavior between the cases reported in the literature and our cases, as our BSCC of the hypopharynx were not detected at a more advanced stage than were the SCC and were in no case associated with another second primary tumor. However, the number of our cases is too small to draw reliable conclusions.
The Combination of Acoustic Rhinometry, Rhinoresistometry and Flow Simulation in Noses before and after Turbinate Surgery: A Model Study
Authors: Grützenmacher S. , Lang C. , Mlynski G.
Published: March 2004

Background: Especially to young examiners, the interpretation of rhinometric findings seems to be difficult. In order to understand rhinometric assessments precisely, knowledge of airflow behavior in the nose is necessary. We therefore investigated the influence of nasal concha surgery on acoustic rhinometry and rhinoresistometry in a model. Method: Six nose models were examined with acoustic rhinometry and rhinoresistometry, each of these models with its lateral wall altered to represent various conditions after nasal concha surgery. Besides, all models were rinsed with water and the flow was visualized for observation. Results and Conclusions: The normal nose presented an even flow distribution over the entire nasal cavity. After nasal concha resection, though, an unfavorable flow course and a strong increase in turbulence were seen. Additionally, flow resistance decreased considerably. In the model with general lateral wall hyperplasia, reduction of the inferior and even of the middle nasal concha showed good functional results. The model revealed a good correlation between the result of flow observation and findings in acoustic rhinometry and rhinoresistometry. Both methods complement one another in their diagnostic outcome.
Evaluation of Inflammatory Reactions and Genotoxic Effects after Exposure of Nasal Respiratory Epithelia to Benzene
Authors: Gosepath Jan , Grebneva Nina , Brieger Juergen , Mann Wolf J.
Published: March 2004

Background: The aim of this study was to identify inflammatory changes as well as genotoxic effects in cultivated human respiratory epithelial cells after in vitro exposure to benzene. Methods: Primary cell cultures of nasal respiratory mucosa were exposed to synthetic air enriched with 5,000 µg/m3 of benzene at an air/liquid interface over 8 h and then to synthetic air only over the following 24 h. Controls were continuously exposed to synthetic air over 32 h. To detect inflammatory reactions, release of prostaglandin E2 was quantified using a competitive enzyme immunoassay. The Comet Assay was used to quantify the ratio of apoptotic cells with benzene-induced DNA fragmentation. Results: Prostaglandin release as well as DNA fragmentation increased after 8 h of exposure and remained elevated throughout the following 24 h but did not increase in controls. Conclusions: High concentrations of benzene induce an inflammatory response and possibly fragmentation of DNA in respiratory epithelial cells. These findings have to be discussed with respect to possible mutagenic or carcinogenic effects of benzene in nasal respiratory cells.
Cochlear Orientation and Dimensions of the Facial Recess in Cochlear Implantation
Authors: Bettman Robert H.R. , Appelman Alex M. M.F. , van Olphen Adriaan F. , Zonneveld Frans W. , Huizing Egbert H.
Published: March 2004

Objective: To study the dimensions of the facial recess and the spatial relationship between the facial recess and the cochlea, using CT scanning in cochlear implantees. Method: In 29 cochlear implantees, preoperative CT scans of the temporal bone were compared with findings done at surgery. The dimensions of the facial recess and the relationship between the facial recess and the cochlea were both measured on a viewing station and classified on printed films by 3 blinded and independent reviewers. Results: No significant relations could be found between either intuitive classification of facial recess width or electrode array insertion feasibility and the measurements with the viewing station. The 3 reviewers had large interobserver variability. In 5 cases, neither intuitive review of the CT scans nor viewing station measurements could predict any of the problems encountered during surgery. Conclusion: Our findings show that intuitive review was not reliable in classifying facial recess width. Viewing station measurements, in classifying the spatial relation between the facial recess and the cochlear basal turn, need a more detailed review in terms of the relationship with the operation direction and the orientation of the basal turn of the cochlea. Advanced imaging techniques, specifically multislice CT, might improve the diagnostic capabilities.
Horizontal Canal Type BPPV: Bilaterally Affected Case Treated with Canal Plugging and Lempert’s Maneuver
Authors: Horii Arata , Imai Takao , Mishiro Yasuo , Yamaji Yoshiko , Mitani Kenji , Kawashima Takayuki , Kubo Takeshi
Published: March 2004

A 54-year-old woman complained of positional vertigo. During 3 months’ observation, the patient showed mostly geotropic or apogeotropic nystagmus due to right canalolithiasis or cupulolithiasis, however, she sometimes showed nystagmus which suggested left horizontal canalolithiasis. We suspected that she suffered from bilateral horizontal canal type benign paroxysmal positional vertigo (BPPV) and performed Lempert’s maneuver for both directions, however, they were ineffective. She underwent canal plugging for right horizontal canal. After surgery she showed no positional nystagmus of right horizontal canal origin. However, apogeotropic nystagmus of the left horizontal canal origin was still observed. This nystagmus changed to geotropic nystagmus and finally disappeared following Lempert’s maneuver for the left side. Bilateral horizontal canal BPPV is difficult to be resolved, probably because physical treatment for one side would move debris to the cupula in the other canal. Canal plugging combined with Lempert’s maneuver to the other side is one treatment option for intractable bilateral horizontal canal BPPV.
Cochlear Implantation after Radical Mastoidectomy: Management of a Challenging Case
Authors: Karatzanis Alexander D. , Chimona Theognosia S. , Prokopakis Emmanuel P. , Kyrmizakis Dionysios E. , Velegrakis George A.
Published: March 2004

Due to increasing experience and technological improvement, the selection criteria for cochlear implantation have improved. Cochlear implant application can now be performed in selected patients with pathological middle ear lesions. The surgical approach to a patient with a history of bilateral radical mastoidectomy is addressed in detail. The benefits of cochlear implantation in this case are also discussed.
Cyclodestructive Procedures
Authors: Fankhauser Franz , Kwasniewska Sylwia , van der Zypen Eugen
Published: March 2004

Laser cyclophotocoagulation is an accepted method of cyclodestruction, such as cyclocryothermy and the application of cyclodiathermy, microwaves and ultrasound. These procedures may be considered as ultima ratios or ‘last-resort interventions’. Also, in cases where surgery is not possible, cyclodestruction may be the initial intervention. Among other lasers, the Nd:YAG and diode lasers are the energy sources of choice. Contact and noncontact methods have about the same clinical efficiency and risk. While immediate complications are transitory, other, late complications, mentioned in the world literature, such as sympathetic ophthalmia, malignant glaucoma and retinal detachment, are more serious but are rare, and their causal relationship with the cyclodestructive procedure is doubtful. However, they still merit our attention. The ultrastructural mechanisms related to cyclocoagulation have been studied. The study of aqueous flow may improve our understanding of cyclophotocoagulation techniques. Cyclophotocoagulation is considered an important cornerstone in glaucoma therapy. The uncertainty of its effect is no greater than that of any other therapeutic measure in the treatment of glaucoma.
Differences between Regressive Eyes and Non-Regressive Eyes after LASIK for Myopia in the Time Course of Corneal Changes Assessed with the Orbscan
Authors: Pan Qing , Gu Yang-shun , Wang Jing , Sheng Ye , Du Chi-xin , Huang Zhi-ming , Xin Shuang-hua
Published: March 2004

The aim of this study was to compare regressive eyes with non-regressive eyes after laser in situ keratomileusis (LASIK) for myopia with regard to the time course of biomechanical changes of the cornea and to evaluate the possible roles of these changes in refractive regression following surgery. 15 eyes of 9 patients with refractive regression and 15 eyes of 11 patients with no refractive regression after LASIK for myopia were enrolled in this study. The time courses of central corneal thickness (CCT) and anterior/posterior corneal curvature radiuses (CCR) were measured with Orbscan slit scanning before and 1 week, 1 month and 3 months after LASIK for myopia. The regressive and non-regressive eyes had similar time courses of CCT before and after LASIK, whereas the 2 groups differed in the time courses of corneal shifting movements. In the regression group, the posterior CCR after LASIK was relatively stable (all p > 0.05). By contrast, in the non-regression group, the postoperative posterior CCR at week 1 had a significantly steeper curvature than that at month 3 (p = 0.000). The anterior CCR in the regression group at week 1 had a significantly flatter curvature than that at month 3 (p = 0.002) postoperatively. In contrast, there was no significant change of anterior CCR postoperatively (all p > 0.05) in the non-regression group. Taken together, these data suggest that refractive regression after LASIK might be mainly induced by corneal protrusion rather than central corneal thickening.