bluuebunny/crossref_metadata_2025 huggingface dataset:
Vestibular Histopathology of the Human Temporal Bone
Authors: RAUCH STEVEN D.
Published: July 2010

Abstract: Histologic sections of the human temporal bone display snapshots of the entire lifetime integrated into the moment the bone enters fixative. The bulk of the literature on vestibular histopathology is anecdotal and descriptive in nature, rather than quantitative. This is because the means of describing and measuring patients' vestibular symptoms are poorly developed, and the complex geometry of the vestibular labyrinth complicates efforts to study it in serial histologic sections. Histopathologic findings in the common peripheral vestibulopathies, including Meniere's syndrome, benign paroxysmal positional vertigo, viral labyrinthitis, vestibular neuronitis, and ototoxicity, have all been described. A new quantitative method for assessment of vestibular otopathology using Nomarski optics has recently been reported. It has been successfully applied to create a normative database of age‐related changes in the vestibular hair cell populations which, in turn, has been used to study the effects of aminoglycoside ototoxicity and Meniere's syndrome. These data provide the first meaningful opportunity to make structure‐function correlations between vestibular function testing and temporal bone pathology in humans. Wider clinical application of vestibular function testing and postmortem temporal bone donation should be promoted by all investigators interested in accumulating the resources necessary to gain a deeper understanding of the human vestibular system in health and disease.
Ocular Compensation due to Labyrinthine Input during Natural Motion
Authors: DEMER JOSEPH L. , CRANE BENJAMIN T.
Published: July 2010

Abstract: With recent technical developments, it has become possible to study eye and head movements in all angular and linear degrees of freedom during natural activities such as standing and treadmill ambulation. Such studies have revealed that normal human gaze stabilization during ambulation is accomplished not only by ocular rotation in response to head rotation, but also by head translation coordinated with head rotation as appropriate to viewing distance. Typically, head translation in a given direction is coupled via an active mechanism with antiphase rotation in the opposite direction, accomplishing some gaze stabilization for near targets and supplementing the vestibulo‐ocular reflex (VOR). Subunity angular VOR gain (eye velocity/head velocity) not only is observed during most natural activities, but also minimizes the disturbance to retinal image stability so that excellent visual acuity can be obtained. The generation of eye movements compensating for head motion during ambulation can be quantitatively modeled as an additive combination of semicircular canal responses, with otolith responses scaling by inverse viewing distance, so angular VOR gain correlates poorly with gaze stability. Compensatory eye movements during self‐generated head rotations appear driven to a significant extent by nonvestibular mechanisms since they cannot be modeled as an additive combination of otolith and canal responses. People with unilateral vestibular deafferentation have normal gaze stability during natural activities such as standing, walking, and running, although gaze stability is impaired in bilateral deafferentation. Limitation of head motion during natural activities is a common strategy in those with reduced peripheral vestibular sensitivity.
Development and Maintenance of Otoconia
Authors: THALMANN RUEDIGER , IGNATOVA ELENA , KACHAR BECHARA , ORNITZ DAVID M. , THALMANN ISOLDE
Published: July 2010

Abstract: The first part of this review deals with recent advances in the understanding of biochemical mechanisms of otoconial morphogenesis. Most important in this regard is the molecular characterization of otoconin 90, the principal matrix protein of mammalian calcitic otoconia, which was found to be a homologue of the phospholytic enzyme PLA2. The unique and unexpected expression pattern of this protein required radical rethinking of traditional concepts. The new data, when integrated with existing information, provide a rational basis for an explanation of the mechanisms leading to crystal nucleation and growth. Based on this information, a hypothetical model is presented that posits interaction of otoconin 90 with microvesicles derived from the supporting cells as a key event in the formation of otoconia. The second part of the review is directed at the controversial subject of maintenance of mature otoconia and systematically analyzes the available indirect information on this topic. A synthesis of these theoretical considerations is viewed in relation to the pathogenesis of the important otoneurologic entities of BPPN and senile otoconial degeneration. The last part of the review deals with several animal models that promise to help elucidate normal and abnormal mechanisms of otoconial morphogenesis, including mineral deficiencies, mutations with selective otoconial agenesis, as well as targeted disruption of essential genes.
Impulsive Testing of Individual Semicircular Canal Function
Authors: HALMAGYI G. M. , AW S. T. , CREMER P. D. , CURTHOYS I. S. , TODD M. J.
Published: July 2010

Abstract: In order to test the human angular vestibulo‐ocular reflex in the dynamic range of normal head movements, we measured 3‐dimensional compensatory eye‐movement responses to low‐amplitude (10–12°), high‐acceleration (3000–4000°/s/s), passive, manually delivered head rotations (head “impulses”) in the three planes of the semicircular canals in normal subjects, in subjects who had recovered from surgical unilateral vestibular deafferentation, and in patients after acute unilateral peripheral vestibulopathy, that is, from vestibular “neuritis.” We found that canal‐plane head impulses away from an intact semicircular canal, that is, toward a lesioned semicircular canal, invariably produce a vestibulo‐ocular reflex with permanently low gain, typically less that 0.4 if the lesion is complete. These results are a necessary consequence of primary semicircular canal afferents being driven into inhibitory saturation by rapid angular accelerations. With practice, clinicians can learn to recognize the telltale compensatory saccades that patients with unilateral loss of semicircular canal function will make if asked to look at an earth‐fixed target during head impulses in any one of the three semicircular canal planes.
Return of Potassium Ion Channels in Regenerated Hair Cells
Authors: CORREIA MANNING J. , RENNIE KATHERINE J. , KOO PAUL
Published: July 2010

Abstract: Recent electrophysiological studies in pigeon have demonstrated that potassium channels are completely functional in regenerated type II hair cells at 21 days post‐treatment (PT) with ototoxic doses of streptomycin. The currents return in the order they appear during development. The mixture of ionic currents in a regenerated type II hair cell in a particular region of the neuroepithelium is the same as in its ancestor in that region. The return of currents in regenerated type I hair cells is more complicated. The dominant conductance gKI is not present until after 70 days PT. Before 70 days, the ionic currents in type I hair cells resemble those of regenerated type II hair cells, suggesting that the ionic currents in type II hair cells might be precursors of the ionic currents in regenerated type I hair cells. New data show that at one year PT, the kinetics and drug sensitivity of the dominant K+ conductance in type I hair cells are identical to gKI. Supporting cells, believed to be the precursors of regenerated type II hair cells, have effectively no voltage‐gated outward potassium channels, suggesting that regenerated type II hair cells must develop these channels de novo. The next step is to understand the mechanisms by which the potassium channel protein is synthesized, migrates through the cytosol, and is inserted into the plasmalemma of regenerating hair cells. These mechanisms are unknown. We propose that intracellular calcium is involved in this process, as well as in the differentiation, proliferation, and gene regulation of precursor cells fated to become hair cells.
Plenary Lecture: Orientation of the Eyes to Gravitoinertial Acceleration
Authors: COHEN BERNARD , MARUTA JUN , RAPHAN THEODORE
Published: July 2010

Abstract:Orientation of the eyes to gravitoinertial acceleration, i.e., to the sum of gravity and the linear accelerations acting on the head and body, is a basic property of the linear vestibulo‐ocular reflex to support vision. Present in a wide range of species from the lateral‐eyed rabbit to frontal‐eyed monkeys and humans, the eyes deviate in pitch, roll and yaw in response to pitch, roll and yaw head movements. The eyes also converge in response to naso‐occipital linear acceleration. This paper provides examples of ocular orientation generated by static tilt and off‐vertical axis rotation in three dimensions and demonstrates specifically how vergence would support vision in the rabbit.
Physiology of the Semicircular Canals after Surgical Plugging
Authors: RABBITT R. D. , BOYLE R. , HIGHSTEIN S. M.
Published: July 2010

Abstract: Inactivation of individual semicircular canals by surgical occlusion (plugging) of the slender duct has been used in basic studies to elucidate the role of individual canal inputs to vestibular‐mediated control systems and in clinical applications to treat certain vestibular disorders. The procedure has been shown to be highly effective in blocking sensitivity of individual canals, at least for moderate angular motion stimuli. Effectiveness does not extend to stimuli involving high accelerations where a residual response persists even after complete occlusion of the duct. The residual can be quite large at high‐stimulus frequencies where sensitivity to angular motion approaches that of patent canals. The overall physiological effect of canal plugging is reported here in terms of the frequency‐dependent attenuation in gain and phase shift of primary afferents. Plug‐canal responses are quantitatively described in terms of biomechanics of the deformable labyrinth.
Regulation of Endolymphatic Fluid Volume
Authors: SALT ALEC N.
Published: July 2010

Abstract: Direct measurements of the dispersal of markers in endolymph have failed to support previously established hypotheses of endolymph homeostasis, specifically longitudinal flow, radial flow, and dynamic flow theories. Rather, they suggest that in the normal state endolymph is maintained without a significant involvement of volume flow at all. Ions appear to be transported into and out of the endolymphatic space in a similar manner to that for a single cell, with each ion transport process contributing to the electrolyte pool. In abnormal volume states, however, longitudinal volume flow of endolymph may contribute to homeostasis. Procedures that enlarge the endolymphatic space result in endolymph flow toward the base of the cochlea, contributing to the removal of electrolytes and volume. Similarly, procedures that decrease cochlear endolymph volume induce apically directed flow in the cochlea, contributing to the addition of electrolytes and volume to the endolymphatic space. The endolymphatic sac responds to endolymph volume disturbance, showing opposite responses to volume increases and decreases. Although evidence is still limited, the endolymphatic sac appears to act as a “bidirectional overflow” system. While volume disturbances originating from out‐of‐balance transport processes anywhere in the labyrinth may be corrected by the sac, dysfunction of the sac itself is likely to have a substantial effect on endolymph status.
Balance Control Analysis as a Method for Screening and Identifying Balance Deficits
Authors: ALLUM J.H. J. , CARPENTER M. G. , ADKIN A. L.
Published: July 2010

Abstract: We propose a two‐step clinical evaluation procedure to identify the possible etiology and laterality of a balance deficit. Step 1 employs a minimum clinical test battery, developed in our labs, to screen for the balance deficit by examining changes to trunk sway for standard clinical stance and gait tests. Step 2 characterizes pathophysiological components in balance corrections, as well as deficits brought about by aging, using biomechanical and electromyographic (EMG) responses to multidirectional stance perturbations. This is best accomplished by delivering stance perturbations to patients standing on a support surface that is tipped in four directions: forwards to the left and right, and backwards to the left and right. This review provides an overview of the two procedures and proposes for the screening procedure a minimum clinical test battery with a score, termed the balance control index (BCI).
Embryo Effects in Human Implantation
Authors: SIMÓN CARLOS , DOMINGUEZ FRANCISCO , REMOHÍ JOSÉ , PELLICER ANTONIO
Published: July 2010

Embryonic implantation requires coordinated development of the blastocyst and the maternal endometrium. Considerable advances have been made in the understanding of the cell biology of human embryo and maternal endometrium as separate entities. Nevertheless, communication between them and their reciprocal effects on each other constitute an exciting and as‐yet unsolved problem in reproductive medicine. Cross‐talk among the embryo, endometrium, and the corpus luteum are known to occur in ruminants and primates; more specifically, endometrial‐embryonic interactions have been reported in rodents and primates. Here, we present updated information in humans on the embryonic regulation of endometrial epithelial molecules such as chemokines, adhesion molecules, antiadhesion molecules, and leptin during the apposition and adhesion phases of human implantation. Also the embryonic induction of apoptosis in endometrial epithelial cells as a mechanism for crossing the epithelial barrier will be described.
Maternal‐Embryonic Cross‐Talk
Authors: HILL JOSEPH A.
Published: July 2010

The human menstrual cycle evolved to prepare the uterus for blastocyst implantation, which is fundamentally under the control of gonadal steroids. Ovarian hormones induce marked morphological, physiological, and biochemical changes within reproductive tissues. These changes in turn induce alterations in the biosynthetic activity and release of a myriad of locally produced proteins into the microenvironment of the reproductive tract. These same factors may be further modified by proteins secreted by the developing embryo and accompanying cumulus cells in intimate contact with reproductive epithelium in a network signaling process. Communication is not one‐way, but rather maternal‐embryonic cross‐talk may occur as maternal proteins are secreted into the microenvironment of the oviduct and uterus, facilitating fertilization and early embryo development and serving as homing beacons for blastocyst nidation. The communicating language facilitating this dialogue includes cytokines, growth factors, angiogenic factors, apoptotic factors, adhesion molecules, and, potentially, homeotic genes.
Role of Steroid Hormone‐Regulated Genes in Implantation
Authors: BAGCHI INDRANI C. , LI QUANXI , CHEON YONG PIL
Published: July 2010

The endometrium acquires the ability to implant the developing embryo within a specific time window, termed the “receptive phase.” During this period, the endometrium undergoes pronounced structural and functional changes induced by the ovarian steroids, estrogen and progesterone, which prepare it to be receptive to invasion by the embryo. These steroid‐induced molecules, when identified, may serve as useful markers of uterine receptivity. In this article, we provide a brief description of one such molecule that has emerged as candidate marker of steroid hormone action in rats and humans during implantation.
Laparoscopic Myomectomy
Authors: DUBUISSON JEAN‐BERNARD , CHAPRON CHARLES , FAUCONNIER ARNAUD , BABAKI‐FARD KATAYOUN
Published: July 2010

The appearance of uterine myomas has been linked to infertility. It has been suggested that surgical management of myomas by laparoscopic myomectomy improves fertility rates in these group of patients. In this paper we initially describe specific aspects of the surgical technique of laparoscopic myomectomy including the set‐up, precise technique for hysteroromy, enucleation of the myoma, suturing of the uterus, and extraction of the myoma. We detail recent findings that demonstrate improved fertility rates in women undergoing laparoscopic myomectomy. We recommend that, when criteria for selection of patients is strictly adhered to and patients present with no other associated infertility, laparoscopic myomectomy be used to increase the implantation rate.
Management of Deep Endometriosis
Authors: CHAPRON CHARLES , DUBUISSON JEAN‐BERNARD
Published: July 2010

Deep endometriosis is defined as an endometriotic lesion that penetrates the retroperitoneal space for a distance of ≥5 mm. Deep endometriosis is extremely active, occurs in phase with eutopic endometrium, evolves progressively with age, and is most often located in the pouch of Douglas, the rectovaginal septum, the uterosacral ligaments, and occasionally in the uterovesical fold. These lesions are associated with pelvic pain, the intensity of which is proportional to the depth of penetration. It is clear that choice of treatment depends on the location of the endometriotic lesion. In this paper we describe our methods for the initial diagnosis and subsequent treatment of deep endometriosis. These include consultation and clinical examination protocols, use of rectal endoscopic ultrasonography (EUS), magnetic resonance imaging (MRI), and transvaginal ultrasonography techniques in diagnosis and surgical treatment approaches.
Cancer and Pregnancy
Authors: CREASMAN WILLIAM T.
Published: July 2010

Carcinoma of the cervix is the most frequently diagnosed cancer in pregnancy. Still, it is an unusual situation. An abnormal Pap smear during pregnancy is a much more common occurrence and fortunately one that can be managed conservatively. Although definitive treatment for intraepithelial disease can be delayed until the postpartum period, diagnostic evaluation should be done when the abnormal Pap smear is present. Invasive cancer management is dependent on gestational age of the fetus. Pregnancy affords an excellent opportunity to screen for cervical neoplasia.
Production of Alginate Beads by Emulsification/Internal Gelation
Authors: PONCELET D.
Published: July 2010

Abstract: Alginate microspheres were produced by emulsification/internal gelation of an alginate sol dispersed within vegetable oil, followed by a reduction in pH to release calcium from an insoluble salt. Microspheres with mean diameters ranging from 50 to 1,000 μm were obtained with standard deviations ranging from 35 to 45% of their mean value. Smooth, spherical beads were obtained with the narrowest size dispersion when using low guluronic and low viscosity alginate and a carbonate complex as calcium vector. The calcium salt must also be included within the alginate sol as a very fine powder to promote homogeneous gelation. Internal gelation was also tested with the dropping method. Observation of the beads produced revealed that the structure of the beads is more homogeneous than observed with external gelation. Shrinking is more important, although the diffusion of large molecules is faster with internal versus external gelation.
Non‐Invasive Monitoring of a Bioartificial Pancreas in Vitro and in Vivo
Authors: CONSTANTINIDIS IOANNIS , LONG ROBERT , WEBER COLIN , SAFLEY SUSAN , SAMBANIS ATHANASSIOS
Published: July 2010

Abstract: Monitoring biochemical processes relevant to the function, survival, and longevity of tissue‐engineered pancreatic constructs is important for the development of an optimum construct design as well as patient care management after implantation. In this report we demonstrate the ability of nuclear magnetic resonance (NMR) techniques to monitor aspects of intracellular metabolism, overall morphology, and distribution of a microencapsulation based bioartificial pancreas in vitro and in vivo.
Optimal Conditions of Transplantable Binary Polyelectrolyte Microcapsules
Authors: BARTKOWIAK ARTUR
Published: July 2010

Abstract: Binary polyanion/oligocation microcapsules, prepared in a one‐step process, are proposed as an alternative to the common alginate/poly‐l‐lysine system used in bioencapsulation technology. The model system is based on natural polysaccharides and involves the anionic sodium alginate, or iota‐carrageenan, complexed with cationic oligochitosan. This system has been characterized with respect to capsule formation, mechanical strength, and permeability. This paper provides a general description of the influence of the most pronounced parameters that can be used as a tool to modulate the properties of binary microcapsules. These parameters have been separated into two categories. The first, which includes molar mass of polyanion, pH, ionic strength, and concentration of both polyelectrolytes, can be used to simultaneously control capsule mechanical and structural properties. The second set, molar mass of polyanion and reaction time, influences only mechanical resistance without altering membrane permeability. Additional issues related to mechanical stability and the possible change of capsule properties following transplantation are discussed.
Mass Production of Embryoid Bodies in Microbeads
Authors: MAGYAR JOSEF P. , NEMIR MOHAMED , EHLER ELISABETH , SUTER NICOLAI , PERRIARD JEAN‐CLAUDE , EPPENBERGER HANS M.
Published: July 2010

Abstract: Embryonic stem cells (ESC) are totipotent cells that can differentiate into a large number of different cell types. Stem cell‐derived, differentiated cells are of increasing importance as a potential source for non‐proliferating cells (e.g., cardiomyocytes or neurons) for future tissue engineering applications. Differentiation of ESC is initiated by the formation of embryoid bodies (EB). Current protocols for the generation of EB are either of limited productivity or deliver EB with a large variation in size and differentiation state. To establish an efficient and robust EB production process, we encapsulated mouse ESC into alginate microbeads using various microencapsulation technologies. Microencapsulation and culturing of ESC in 1.1% alginate microbeads gives rise to discoid colonies, which further differentiate within the beads to cystic EB and later to EB containing spontaneously beating areas. However, if ESC are encapsulated into 1.6% alginate microbeads, differentiation is inhibited at the morula‐like stage, so that no cystic EB can be formed within the beads. ESC colonies, which are released from 1.6% alginate microbeads, can further differentiate to cystic EB with beating cardiomyocytes. Extended supplementation of the growth medium with retinoic acid promotes differentiation to smooth muscle cells.
Pectin‐Based Microspheres
Authors: ESPOSITO ELISABETTA , CORTESI RITA , LUCA GIOVANNI , NASTRUZZI CLAUDIO
Published: July 2010

Abstract: This paper reports on (a) the production of pectin microspheres and (b) the influence of different experimental parameters and ionic crosslinking on morphological and dimensional characteristics of pectin microspheres. Morphological and dimensional characteristics of pectin were analyzed as a function of the type of pectin, the dispersing phase, the stirring speed, and the emulsifying agent. Crosslinking by calcium chloride and the encapsulation of antibiotics (i.e., metronidazol and tetracycline) gave particles morphologically similar to empty particles but with slower swelling kinetic.
Approaches to Development of Microencapsulated Form of the Live Measles Vaccine
Authors: NECHAEVA E. A. , VARAKSIN N. , RYABICHEVA T. , SMOLINA M. , KOLOKOLTSOVA T. , VILESOV A. , AKSENOVA N. , STANKEVICH R. , ISIDOROV R.
Published: July 2010

Abstract: Development of delivery of antigens and antigenic complexes using microcapsules or microgranules made of pH‐dependent polymers is one of several high priority directions of modern vaccinology. These polymers should protect the virus from acid gastric medium, dissolve or swell readily in weakly alkaline intestinal medium, in no way decrease the specific activities of viral antigens, promote their penetration into intestinal mucosa, and possess adjuvant properties. The State Research Center Vector and “DELSI” are developing the technology for production of microencapsulated form of the live measles vaccine L‐16 viruses for oral administration. The authors have so far succeeded in selecting and characterizing a number of polymers that are promising for microencapsulated vaccine and for testing of virus titers and immune response of experimental samples of a new vaccine in animals. Control of samples in guinea pigs demonstrated that the encapsulated measles virus retained its specific activity and capability for inducing immune response in experimental animals.
Transplantation of Alginate Microcapsules with Proliferating Cells in Mice
Authors: ROKSTAD ANNE MARI , KULSENG BÅRD , STRAND BERIT L. , SKJÅK‐BRÆK GUDMUND , ESPEVIK TERJE
Published: July 2010

Abstract: Alginate microcapsules may be used to encapsulate therapeutic cells and, thereby, to protect them from the host immune system. Both the biomaterial, as well as the therapeutic cells, may give rise to immunological reactions. We have developed methods that are useful in the study of capsule biocompatibility, as well as reactions against the grafts. These imply investigation of the survival of the encapsulated cells as well as fibrotic reactions against the microcapsules. Studies were performed in Balb/c mice with empty alginate‐PLL‐alginate microcapsules as well as microcapsules containing cells of human or mouse origin. Confocal laser scanning microscopy (CLSM) was used to visualize live and dead cells within the microcapsules and to define some of the cells involved in the fibrotic reaction against the microcapsules. In both grafts, live cells were detected seven days after transplantation. Minor fibrotic reactions were found against empty alginate‐PLL‐alginate microcapsules and to microcapsules containing mouse cells. An extensive fibrotic reaction was found one week after transplantation against microcapsules containing human cells, and the secretion of therapeutic protein endostatin had ceased. Fibroblasts and macrophages were involved in the fibrotic reaction against the xenograft.
Cellular Support Systems for Alginate Microcapsules Containing Islets, as Composite Bioartificial Pancreas
Authors: CALAFIORE RICCARDO , LUCA GIOVANNI , CALVITTI MARIO , NERI LUCA M. , BASTA GIUSEPPE , CAPITANI SILVANO , BECCHETTI ENNIO , BRUNETTI PAOLO
Published: July 2010

Abstract: To improve the functional performance of microencapsulated islets, we examined the effects of putative cellular support systems, consisting of rat purified Sertoli cells (SC) and astrocytes (AA), on coenveloped allogeneic islets. Coincubation of islets with SC but not AA, resulted in significant stimulation of β cell mitogenesis, coupled with a significant increase in in vitro glucose‐stimulated insulin release. Preliminarily, the xenotransplantation of coencapsulated rat islets and homologous SC significantly prolonged remission of hyperglycemia in diabetic mice.
In Vitro Test of New Biomaterials for the Development of a Bioartificial Pancreas
Authors: LEMBERT N. , PETERSEN P. , WESCHE J. , ZSCHOCKE P. , ENDERLE A. , DOSER M. , PLANCK H. , BECKER H. D. , AMMON H.P. T.
Published: July 2010

Abstract: The implantation of macroencapsulated islets has the potential to restore endogenous insulin secretion in type 1 diabetics, with no need for lifetime immunosuppression. To match the physiological fluctuations of blood glucose concentrations with appropriate insulin release, the macroencapsulation material must combine immunoprotection with optimal diffusion properties for glucose and insulin. The impact of chemical modifications of polysulphone (PSU) capillary polymers with a cutoff of 50 kD on glucose‐induced insulin secretion of macroencapsulated rat islets was studied in perifusion experiments. The insulin release of free‐floating islets showed the typical rapid response to glucose stimulation. Total insulin release (AUC between minute 30 and 120 of perifusion) reached 117 ± 22 ng/ml. Blending PSU with polyvinylpyrrolidone or sodium‐dodecyl‐sulfate was not suitable for islet macroencapsulation, since glucose‐induced insulin release was absent or disturbed. Hydroxy‐methylation (CH2OH) of PSU improved the secretory behavior of macroencapsulated islets depending on the degree of PSU substitution (DS 0.8, AUC 62 ± 15 ng/ml; DS 1.8, 111 ± 24 ng/ml). In highly substituted PSU‐capillaries the kinetics of glucose‐induced insulin release was very similar to that observed in free‐floating islets. Two consecutive glucose stimulations potentiated insulin release of free‐floating islets during the second period of stimulation. Furthermore, freshly isolated macroencapsulated islets responded with more efficient insulin secretion after the initial priming. In conclusion, in vitro membrane screening identified highly substituted hydroxy‐methylated PSU as the material of choice for islet encapsulation in a bioartificial pancreas.
Advances in Bioartificial Liver Assist Devices
Authors: PATZER JOHN F.
Published: July 2010

Abstract: Rapid advances in development of bioartificial liver assist devices (BLADs) are exciting clinical interest in the application of BLAD technology for support of patients with acute liver failure. Four devices (Circe Biomedical HepatAssist®, Vitagen ELAD™, Gerlach BELS, and Excorp Medical BLSS) that rely on hepatocytes cultured in hollow‐fiber membrane technology are currently in various stages of clinical evaluation. Several alternative approaches for culture and perfusion of hepatocytes have been evaluated in preclinical, large animal models of liver failure, or at a laboratory scale. Engineering design issues with respect to xenotransplantation, BLAD perfusion, hepatocyte functionality and culture maintenance, and ultimate distribution of a BLAD to a clinical site are delineated.
The Influence of Extracellular Matrix on the Generation of Vascularized, Engineered, Transplantable Tissue
Authors: CASSELL OLIVER C.S. , MORRISON WAYNE A. , MESSINA AURORA , PENINGTON ANTHONY J. , THOMPSON ERIK W. , STEVENS GEOFFREY W. , PERERA JILSKA M. , KLEINMAN HYNDA K. , HURLEY JOHN V. , ROMEO ROSALIND , KNIGHT KENNETH R.
Published: July 2010

Abstract: In a recently described model for tissue engineering, an arteriovenous loop comprising the femoral artery and vein with interposed vein graft is fabricated in the groin of an adult male rat, placed inside a polycarbonate chamber, and incubated subcutaneously. New vascularized granulation tissue will generate on this loop for up to 12 weeks. In the study described in this paper three different extracellular matrices were investigated for their ability to accelerate the amount of tissue generated compared with a no‐matrix control. Poly‐d,l‐lactic‐co‐glycolic acid (PLGA) produced the maximal weight of new tissue and vascularization and this peaked at two weeks, but regressed by four weeks. Matrigel was next best. It peaked at four weeks but by eight weeks it also had regressed. Fibrin (20 and 80 mg/ml), by contrast, did not integrate with the generating vascularized tissue and produced less weight and volume of tissue than controls without matrix. The limiting factors to growth appear to be the chamber size and the capacity of the neotissue to integrate with the matrix. Once the sides of the chamber are reached or tissue fails to integrate, encapsulation and regression follow. The intrinsic position of the blood supply within the neotissue has many advantages for tissue and organ engineering, such as ability to seed the construct with stem cells and microsurgically transfer new tissue to another site within the individual. In conclusion, this study has found that PLGA and Matrigel are the best matrices for the rapid growth of new vascularized tissue suitable for replantation or transplantation.
Microsatellite Alterations Detected in the Serum of Early Stage Breast Cancer Patients
Authors: TABACK BRET , GIULIANO ARMANDO E. , HANSEN NORA M. , HOON DAVE S. B.
Published: July 2010

Abstract: Breast cancer is the most common malignancy affecting women. Advances in screening have resulted in an increasing trend towards detecting earlier stage tumors associated with a longer disease‐free survival. Because of this prolonged latency period, it is critical to identify patients early in their disease course who are at increased risk for recurrence, whereby treatment decisions may be altered accordingly based on more precise information. Molecular markers that demonstrate prognostic importance as well as utility for assessing subclinical disease progression offer one such approach. Specifically, circulating microsatellite alterations that reflect those genetic events occurring in tumors and that can be serially assessed through a minimally invasive procedure are a logistically practical method. In this study, serum was collected preoperatively from 56 patients with early stage breast cancer (AJCC stages I/II) and assessed for loss of heterozygosity (LOH) using 8 microsatellite markers. Twelve (21%) of 56 patients demonstrated LOH in their serum for at least one marker. Histopathologic correlation revealed an association between the presence of circulating LOH in serum and those tumors with increased proliferation indices as characterized by an increased diploid index, elevated MIB‐1 fraction, and abnormal ploidy. These findings demonstrate the presence of circulating microsatellite alterations in the serum from patients with early stage breast cancer. The association of known poor prognostic features found in tumors with increased nuclear activity not only suggests a possible etiology for their presence, but also offers a potential blood‐based surrogate marker for this disease that may demonstrate clinical utility in long‐term follow‐up studies.
A Possible Noninvasive Method for the Detection of Bladder Cancer in Patients
Authors: UTTING MICHAEL , WERNER WOLFRAM , MÜLLER GABRIELE , SCHUBERT JÖRG , JUNKER KERSTIN
Published: July 2010

Abstract: Six microsatellite markers were selected to detect shifts or loss of heterozygosity (LOH) in urine, serum, and plasma samples of 44 bladder cancer patients. After centrifugation at 15,000g, we used supernatants for DNA analysis only. Tumor specimens were obtained by transurethral resection (TUR). Genetic alterations were detected in 33 of the 44 bladder tumors (75%). After polymerase chain reaction (PCR), DNA was detectable in 96% of all body fluid samples. Twenty‐six percent of the detected microsatellite alterations of free DNA were tumor‐specific, but 82% of all microsatellite changes of the tumors could be detected in body fluids. The study indicates that the simultaneous and multiple investigations of highly specific microsatellite markers could have a clinical relevance as a noninvasive tool for diagnosis and screening of bladder cancer. However, new ways for the sensitive DNA isolation of body fluids are needed.
Serum/Plasma Viral DNA
Authors: MUTIRANGURA APIWAT
Published: July 2010

Abstract: Following reports describing circulating tumor DNA, serum/plasma viral nucleic acid has shown its potential as a new diagnostic target in cancer. In the majority of examples of viral carcinogenesis, the viral genome is consistently present in certain tumors and serves as an effective marker. This article reviews recent findings, proposes possible mechanisms, and examines the potential clinical application of serum/plasma Epstein‐Barr virus (EBV) DNA in nasopharyngeal cancer (NPC) and human papillomavirus (HPV) DNA in cervical carcinoma (CC). These tumors share a DNA viral etiology and present similar histopathological findings. However, plasma EBV and HPV DNA are distinct in several aspects, including incidence, mechanism of release from tumor, and clinical application. Both circulating cell‐free EBV and HPV DNA reveal the same viral type as their matched tumors, indicating both are derived from the neoplastic tissue. Plasma viral DNA incidence and copy number are high in NPC, but low in HPV‐associated cancers. Whereas much EBV DNA in NPC is episomal, the resistance to DNase treatment of serum EBV DNA and evidence confirming lytic EBV replication in NPC suggest that a reasonable proportion of plasma EBV DNA is virions. On the contrary, plasma HPV genomes, as in CC, integrate into host chromosome. Plasma EBV DNA copy number, by quantitative PCR, is related to tumor mass, predicts prognosis, measures immediate response to treatment, and is useful in early detection of recurrence. Plasma HPV DNA, on the other hand, is associated with and can be considered as an early tumor marker for distant metastasis.
Circulating Cell‐Free Epstein‐Barr Virus DNA Levels in Patients with EBV‐Associated Lymphoid Malignancies
Authors: LEI KENNY I. K. , CHAN LISA Y. S. , CHAN WING Y. , JOHNSON PHILIP J. , LO Y. M. DENNIS
Published: July 2010

Abstract: Epstein‐Barr virus (EBV) is a human lymphotrophic herpesvirus implicated in the development of several lymphoid malignancies. Recently, detection of cell‐free EBV DNA in sera or plasma from patients with EBV‐associated malignancies has been reported. However, most published studies are qualitative in nature, with only a few providing quantitative data. We have described the temporal changes of plasma EBV DNA levels in patients with EBV‐associated lymphoid malignancies during therapy using quantitative real‐time PCR. A close correlation between plasma EBV DNA levels and therapeutic response was observed. Our aim was to update our results and to assess the role of the plasma EBV DNA levels as a molecular marker for disease monitoring in patients with EBV‐associated lymphoid malignancies.
Gross Elevation of TT Virus Genome Load in the Peripheral Blood Mononuclear Cells of Cancer Patients
Authors: ZHONG SHENG , YEO WINNIE , TANG MANDY W. , LIN XIAO‐RONG , MO FRANKIE , HO WING M. , HUI PUN , JOHNSON PHILIP J.
Published: July 2010

Abstract: TT virus (TTV) is a recently described circular DNA virus of about 3.8 kb, which is related to the circoviridae viruses. It is commonly detected in healthy subjects and no association with any specific disease has been established. TTV was initially thought to be hepatotropic, but subsequent reports have shown that it is detectable in other tissues, including kidney, prostate, mammary gland, brain, bone marrow, and peripheral blood mononuclear cells. Plasma samples from cancer patients and healthy subjects were tested for the presence or absence of TTV by heminested polymerase chain reaction (PCR). We also developed a quantitative competitive PCR (QC‐PCR) assay for TTV that permits accurate measurement of TTV DNA load. Using this assay, the TTV genome load in peripheral blood mononuclear cells (PBMCs) of healthy control subjects (n= 50) and patients with various types of cancer (n= 148), including breast cancer, non‐Hodgkin's lymphoma, colon cancer, hepatocellular carcinoma, nasopharyngeal carcinoma, and other cancers, was measured. TTV DNA was detected in 69 of 100 plasma samples (69%) of cancer patients tested and in 39 of 100 plasma samples (39%) randomly selected from 1000 plasma samples of blood donors (p < 0.05). TTV DNA was detectable in the PBMCs of 99% of the cancer patients and 86% of the controls. However, the median virus load was more than 100‐fold higher in the cancer patients (3599 copies/100,000 cells) than among the controls (30 copies/100,000 cells; p < 0.0001). There was no significant difference in TTV load among the different cancer types. Using a cutoff value of >250 copies per 100,000 PBMCs, 93.2% of cancer patients were “positive” compared to only 4% of healthy control subjects. Almost all the cancer patients have TTV infection and their TTV genome load in PBMCs is significantly higher than that in control subjects. It remains to be elucidated whether such findings are specific to cancer patients or occur in all seriously ill subjects.
Quantitative Analysis of Fetal DNA in Maternal Plasma in Pathological Conditions Associated with Placental Abnormalities
Authors: SMID MADDALENA , VASSALLO ANTONIA , LAGONA FIORENZA , VALSECCHI LUCA , MANISCALCO LUCIA , DANTI LUANA , LOJACONO ANDREA , FERRARI AUGUSTO , FERRARI MAURIZIO , CREMONESI LAURA
Published: July 2010

Abstract: An increased fetal DNA concentration in maternal plasma has been observed in placental pathological conditions associated with hypertension and preeclampsia. To confirm these data, we performed real‐time quantitative PCR on the SRY gene in a group of physiological and pathological male‐bearing pregnancies. In 78 physiological pregnancies, fetal DNA concentration in maternal plasma was 20.7, 13.4, 23.6, and 74.8 genome‐equivalents (g.e.)/mL during the first, second, and third trimesters and at term, respectively. In 10 preeclamptic women, fetal DNA concentration ranged from 59.3 to 615.2 g.e./mL (median: 332.9). In 7 women with preeclampsia and IUGR (intrauterine growth retardation), fetal DNA ranged from 96.5 to 859 g.e./mL (median: 146.8). In 4 women with IUGR and hypertension, fetal DNA ranged from 34 to 473.5 g.e./mL (median: 142.4). In 3 patients with IUGR, fetal DNA ranged from 168.6 to 519.7 g.e./mL (median: 308.1). In 2 patients with IUGR and HELLP (hemolysis, elevated liver enzymes, and low platelet count) syndrome, fetal DNA concentration ranged from 105 to 394.1 g.e./mL (median: 249.7). Four women who developed preeclampsia some weeks later showed fetal DNA levels within the physiological range. These data suggest that increased fetal DNA concentrations might represent a valuable marker of placental abnormalities and suggest that this rise may precede clinical manifestation of preeclampsia by only a few weeks.
Fetal DNA Diagnosis from Maternal Blood
Authors: IKAWA K. , YAMAFUJI K. , UKITA T. , KUWABARA S. , IGARASHI T. , TAKABAYASHI H.
Published: July 2010

Abstract: Development of a real‐time quantitative TaqMan PCR assay permits the high‐quality analysis of DNA or RNA. This study demonstrates the successful detection of single locus genes from single NRBCs, retrieved by micromanipulation of cells on a blood smear slide. Quantitative data in relation to the concentration of a single locus DNA amplified by PEP from a single NRBC are also provided. In summary, a PEP‐TaqMan system can potentially be a powerful tool for noninvasive fetal DNA diagnosis through the use of maternal blood.
Detection of Maternal DNA in Umbilical Cord Plasma by Fluorescent PCR Amplification of Short Tandem Repeat Sequences
Authors: BAUER MARGIT , ORESCOVIC IRMGARD , SCHOELL WOLFGANG M. , BIANCHI DIANA W. , PERTL BARBARA
Published: July 2010

Abstract: Recently, maternal DNA was detected in umbilical cord blood using PCR amplification of minisatellite sequences. The presence of maternal DNA was demonstrated in 1% to 100% of umbilical cord blood samples. The objective of this study was to determine the frequency of cord blood contamination by maternal genetic material. We used fluorescent PCR amplification of highly polymorphic short tandem repeat (STR) markers to detect maternal DNA in umbilical cord plasma.
Detection of Tumor‐Associated Circulating mRNA in Patients with Disseminated Malignant Melanoma
Authors: RAPPL G. , HASSELMANN D. O. , RÖßLER M. , UGUREL S. , TILGEN W. , REINHOLD U.
Published: July 2010

Abstract: It has been suggested that extracellular mRNA might be released from tumor cells and might be protected from serum RNase by proteins or proteolipid complexes. Our group has recently assessed the potential value of extracellular RNA detection by RT‐PCR in the peripheral blood of patients with metastatic melanoma.
Detection of Mammaglobin mRNA in the Plasma of Breast Cancer Patients
Authors: GAL SHIRA , FIDLER CARRIE , LO Y. M. DENNIS , CHIN KENNY , MOORE JOHN , HARRIS ADRIAN L. , WAINSCOAT JAMES S.
Published: July 2010

Abstract: It has been suggested that mammaglobin may be a useful marker for breast cancer clinical research. Studies investigating the detection of mRNA by RT‐PCR from circulating carcinoma cells in the peripheral blood of breast cancer patients have shown that mammaglobin is a highly specific marker and correlates with several prognostic factors, such as lymph node involvement. We aimed to detect cell‐free mammaglobin mRNA in the plasma of breast cancer patients and to investigate whether it can be used as a marker for diagnosis of breast cancer.
Hepatitis B Virus Nucleic Acids Circulating in the Blood
Authors: BREITKREUTZ RAOUL , ZHANG WEI , LEE MIEUN , HOFFMANN ARMIN , TOKUS MEHMET , SU QIN , SCHRÖDER CLAUS H.
Published: July 2010

Abstract: Circulating nucleic acids in serum and plasma are common in a variety of disease conditions. Here, we focus (i) on our approach for the detection of various hepatitis B virus (HBV)‐related nucleic acids in liver tissue and in serum, (ii) on the progression of the chronic HBV infection, (iii) on the relation of HBV‐specific nucleic acids circulating in the blood of patients with hepatocellular carcinoma, and in general (iv) on the diagnostic potential of circulating HBV nucleic acids.
Pathogenesis of HIV‐Related Pulmonary Hypertension
Authors: PELLICELLI ADRIANO M. , PALMIERI FABRIZIO , CICALINI STEFANIA , PETROSILLO NICOLA
Published: July 2010

Abstract:Human immunodeficiency virus (HIV)‐related pulmonary hypertension (HRPR) is a cardiovascular complication of HIV infection that has been recognized in the last years with increasing frequency. The etiology of HRPH is unknown. All the attempts to isolate HIV on pulmonary vessels in HRPH patients failed, and an indirect role for HIV in this disease has been hypothesized. Current theories on the pathogenesis focus on abnormalities of endothelial and smooth muscle cells of pulmonary vasculature. Endothelial and smooth muscle cell injury could be due to a high production or to a reduced clearance of cytokines in these patients. In fact, in several studies high levels of ET‐1, IL‐1α, IL‐6 and PDGF in primary pulmonary hypertension (PPH) and in HRPH have been found. HIV gp 120 could induce the production of these cytokines by a stimulation of monocytes/macrophages. A high α1‐adrenoreceptors stimulation of pulmonary vessels could be also implicated in the pathogenesis of HRPH. Chronic hypoxia is observed with increased frequency in HIV patients, and this could induce a chronic stimulation of α1‐receptors of pulmonary vasculature with typical pathological changes. However, only a small percentage of HIV−patients develop HRPH. This observation suggests the existence of an idiosyncratic susceptibility to the development of vascular disease. This susceptibility could have a genetic basis, and might be determined by particular major histocompatibility complex alleles.
“Tissue” Transglutaminase Expression in HIV‐Infected Cells
Authors: AMENDOLA ALESSANDRA , RODOLFO CARLO , DI CARO ANTONINO , CICCOSANTI FABIOLA , FALASCA LAURA , PIACENTINI MAURO
Published: July 2010

Abstract: The cytopathic effect of HIV has been shown to be associated with the induction of apoptosis and the inhibition of proliferation of T cells. However, the cellular and molecular mechanisms at the basis of the dramatic immune cell loss caused by HIV in patients suffering from acquired immunodeficient syndrome (AIDS), are not yet fully established. We demonstrated that “tissue” transglutaminase (tTG) gene expression is induced in the immune system of seropositive individuals (peripheral blood mononuclear cells and lymph nodes). tTG is a multifunctional protein involved in a variety of fundamentally important cellular functions, in addition to cell death by apoptosis. The presence of high tTG levels in immune‐competent cells of HIV+ persons might exert an important role in HIV‐infection by influencing viral production. We propose that, in addition to its multiple functions, tTG might interfere with HIV replication by altering the viral mRNA trafficking between the nucleus and the cytoplasm. This effect might be due to its specific interaction with eIF5A, a cellular partner of HIV Rev protein, which is essential for HIV replication in immune‐competent cells. Given the presence of high tTG levels in HIV+ individuals, it would be of interest to pursue the potential role of this multifunctional protein in the development of strategies aimed at the pharmacologic regulation of HIV production.