bluuebunny/crossref_metadata_2025 huggingface dataset:
CONTROL AND ERROR PREVENTION IN CONDENSED MATTER QUANTUM COMPUTING DEVICES
Authors: BYRD M. S. , WU L.-A.
Published: July 2007

Proposals for scalable quantum computing devices suffer not only from decoherence due to their interaction with the environment, but also from severe engineering constraints. For example, our ability to implement quantum gates is determined, in part, by the experimentally available interactions with which quantum information may be processed. Here we review a practical solution to some of the major concerns, control and error prevention, addressing solid state proposals for quantum computing devices. Some noise is eliminated by encoding a logical qubit into two qubits, other noise is reduced by an efficient set of decoupling pulse sequences. The same encoding removes the need for single-qubit operations which pose a difficult design constraint. We also discuss several generalizations which follow from this work.
MAXENT APPROACH TO QUBITS
Authors: SARRIS C. M. , PROTO A. N. , MALIK F. B.
Published: July 2007

We consider the Hubbard-like Hamiltonian used in Physica B 352 (2004) 269-279, using the MaxEnt approach and a CSCO, as the set of relevant operators which, obviously, close a partial Lie algebra with the Hamiltonian. So, it is possible to define a positive definite metric on the space spanned by the mean values of the CSCO. Particularly, the selected operators represent the occupation number, the aligned and antialigned pairs per site, respectively. The interesting question to be examined here is whether the above mentioned Hamiltonian have the property that the expectation values of a suitable operator are indeed zero and one (or a constant) qubits, and zero and +1 and -1, i.e., qutrits.
THERMAL COHERENT STATES, A BROADER CLASS OF MIXED COHERENT STATES, AND GENERALIZED THERMO-FIELD DYNAMICS
Authors: BISHOP RAYMOND F. , VOURDAS APOSTOLOS
Published: July 2007

We introduce coherent mixed states (or thermal coherent states) associated with the displaced harmonic oscillator at nonzero temperature (T ≠ 0), as a "random" (or "thermal" or "noisy") basis in Hilbert space. A resolution of the identity for these states is proven and is used to generalize the usual pure (T = 0) coherent state formalism to the mixed (T ≠ 0) case. This new formalism for thermal coherent states is then further generalized to a broader class of so-called negative-binomial mixed states. It is known that the negative-binomial distribution is itself intimately related to the discrete series of SU(1,1) representations. We consider the pure SU(1,1) coherent states in the two-mode harmonic oscillator space, and show how our negative-binomial mixed states arise from taking the partial trace with respect to one of these two modes. This observation is then used to show how the formalism of thermo-field dynamics may be generalized to a correspondingly much broader negative-binomial-field dynamics, which we expect to have many uses.
ERGODIC CONDITION AND MAGNETIC MODELS
Authors: LEE M. HOWARD
Published: July 2007

A condition for ergodicity is derived, applicable to a Hermitian many body model in both the classical and quantum domains. Using this ergodic condition, the validity of the ergodic hypothesis is examined in certain solvable 1d magnetic models. A simple but general picture has emerged which shows why the hypothesis can be valid and why it can also fail.
GROUPS OF TWO-BRAID VIRTUAL KNOTS
Authors: KANENOBU TAIZO , TSUJI KAZUNORI
Published: July 2007

Giving a presentation of the group of a 2-braid virtual knot or link, we consider the groups of three families of 2-braid virtual knots. Each of them has a certain feature; for example, we can show: for any positive integer N, there exists a virtual knot group with an element of order N. It is known that the collection of the virtual knot groups is the same as that of the ribbon T2-knot groups. Using our examples we discuss the relationship among the virtual knot groups and other knot groups such as ribbon S2-knot groups, S2-knot groups, T2-knot groups, and S3-knot groups.
KAUFFMAN-TYPE POLYNOMIAL INVARIANTS FOR DOUBLY PERIODIC STRUCTURES
Authors: GRISHANOV SERGEI A. , MESHKOV VADIM R. , OMEL'CHENKO ALEXANDER V.
Published: July 2007

A two-variable polynomial invariant of non-oriented doubly periodic structures is proposed. A possible application of this polynomial for the classification of textile structures is suggested.
INVOLUTIONS OF KNOTS THAT FIX UNKNOTTING TUNNELS
Authors: FUTER DAVID
Published: July 2007

Let K be a knot that has an unknotting tunnel τ. We prove that K admits a strong involution that fixes τ pointwise if and only if K is a two-bridge knot and τ its upper or lower tunnel.
ARTHROSCOPICALLY ASSISTED REDUCTION WITH VOLAR PLATING OR EXTERNAL FIXATION FOR DISPLACED INTRA-ARTICULAR FRACTURES OF THE DISTAL RADIUS IN THE ELDERLY PATIENTS
Authors: Hattori Yasunori , Doi Kazuteru , Estrella Emmanuel P. , Chen Guofen
Published: July 2007

Twenty-eight patients older than 70 years with AO type C fracture of the distal radius were treated with arthroscopically assisted reduction combined with volar plating or external fixation. The patients were followed up for an average of 24.9 ± 16.1 months. The average score was 80.1 ± 10.5 according to the modified system of Green and O'Brien. Eight patients had an excellent result, 11 had a good result, seven had a fair result, and two had a poor result. Twenty-three patients were able to return to their previous activities level or occupation without any restriction. On the basis of these results, we concluded that arthroscopically assisted reduction combined with volar plating or external fixation is one of the useful options for the treatment of a displaced intra-articular fracture of the distal radius in elderly patients who are physiologically young or active.
TWO CASES OF ENDOSCOPIC MANAGEMENT OF CARPAL TUNNEL SYNDROME IN MACRODACTYLY PATIENTS
Authors: Yoshida A. , Okutsu I. , Hamanaka I. , Morimoto S.
Published: July 2007

Some cases of carpal tunnel syndrome in macrodactyly patients have been reported. We performed endoscopic carpal canal release on two unilateral macrodactyly patients suffering from bilateral carpal tunnel syndrome. We measured carpal canal pressure before performing endoscopic surgery using the Universal Subcutaneous Endoscope system to confirm median nerve compression. We diagnosed median nerve compression in each patient due to the high preoperative carpal canal pressure. Carpal canal pressure immediately decreased to within normal range following release of both the flexor retinaculum and the distal holdfast fibres of the flexor retinaculum.

One patient recovered to within normal in terms of sensory disturbances and abductor pollicis brevis muscle strength. The other patient showed improvement in terms of sensory disturbance, however, muscle power did not recover because this patient had suffered from carpal tunnel syndrome for ten years.

Endoscopic carpal canal release and decompression surgery was effective for carpal tunnel syndrome in both macrodactyly patients.
MAFFUCCI SYNDROME: A RARE AND IMPORTANT DIFFERENTIAL DIAGNOSIS FOR LUMPY HANDS
Authors: Southwell-Keely James Peter , Sira Siraj , Cohen Adrian
Published: July 2007

Maffucci syndrome belongs to a group of disorders known as enchondromatoses. First described in 1881, it features multiple enchondromas and vascular abnormalities, mainly haemangiomas. The syndrome is a variant of Ollier's disease, which consists solely of multiple enchondromas. This case serves to highlight important features of a rare condition.
Responses of mitochondrial biogenesis and function to maternal diabetes in rat embryo during the placentation period
Authors: Alcolea M. P. , Lladó I. , García-Palmer F. J. , Gianotti M.
Published: July 2007

Mitochondria are cellular organelles that have been reported to be altered in diabetes, being closely related to its associated complications. Moreover, mitochondrial biogenesis and function are essential for proper embryo development throughout the placentation period, occurring during organogenesis, when a great rate of congenital malformations have been associated with diabetic pregnancy. Thus, the aim of the current work was to investigate the effect of the diabetic environment on mitochondrial function and biogenesis during the placentation period. For this purpose, we studied the oxidative phosphorylation system (OXPHOS) enzymatic activities as well as the expression of genes involved in the coordinated regulation of both mitochondrial and nuclear genome (PGC-1α, NRF-1, NRF-2α, mtSSB, and TFAM) and mitochondrial function (COX-IV, COX-I, and β-ATPase) in rat embryos from control and streptozotocin-induced diabetic mothers. Our results reflected that diabetic pregnancy retarded and altered embryo growth. The embryos from diabetic mothers showing normal morphology presented a reduced content of proteins regulated through the PGC-1α mitochondriogenic pathway on gestational day 12. This fact was accompanied by several responses that entailed the activation of OXPHOS activities on the same day and the recovery of the content of the studied proteins to control levels on day 13. As a result, the mitochondria of these embryos would reach a situation close to control on day 13 that could allow them to follow the normal mitochondriogenic schedule throughout a gestational period in which the mitochondrial differentiation process is critical. Nevertheless, malformed embryos from diabetic mothers seemed to show a lower adaptation capability, which could exacerbate their maldevelopment.
Load-dependent effects of duodenal glucose on glycemia, gastrointestinal hormones, antropyloroduodenal motility, and energy intake in healthy men
Authors: Pilichiewicz Amelia N. , Chaikomin Reawika , Brennan Ixchel M. , Wishart Judith M. , Rayner Christopher K. , Jones Karen L. , Smout Andre J. P. M. , Horowitz Michael , Feinle-Bisset Christine
Published: July 2007

Gastric emptying is a major determinant of glycemia, gastrointestinal hormone release, and appetite. We determined the effects of different intraduodenal glucose loads on glycemia, insulinemia, glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP) and cholecystokinin (CCK), antropyloroduodenal motility, and energy intake in healthy subjects. Blood glucose, plasma hormone, and antropyloroduodenal motor responses to 120-min intraduodenal infusions of glucose at 1) 1 (“G1”), 2) 2 (“G2”), and 3) 4 (“G4”) kcal/min or of 4) saline (“control”) were measured in 10 healthy males in double-blind, randomized fashion. Immediately after each infusion, energy intake at a buffet meal was quantified. Blood glucose rose in response to all glucose infusions ( P < 0.05 vs. control), with the effect of G4 and G2 being greater than that of G1 ( P < 0.05) but with no difference between G2 and G4. The rises in insulin, GLP-1, GIP, and CCK were related to the glucose load ( r > 0.82, P < 0.05). All glucose infusions suppressed antral ( P < 0.05), but only G4 decreased duodenal, pressure waves ( P < 0.01), resulted in a sustained stimulation of basal pyloric pressure ( P < 0.01), and decreased energy intake ( P < 0.05). In conclusion, variations in duodenal glucose loads have differential effects on blood glucose, plasma insulin, GLP-1, GIP and CCK, antropyloroduodenal motility, and energy intake in healthy subjects. These observations have implications for strategies to minimize postprandial glycemic excursions in type 2 diabetes.
Three-dimensional architecture of collecting ducts, loops of Henle, and blood vessels in the renal papilla
Authors: Pannabecker Thomas L. , Dantzler William H.
Published: July 2007

Three-dimensional architecture of vasculature and nephrons in rat renal papilla was assessed by digital reconstruction. Descending vasa recta (DVR), ascending vasa recta (AVR), descending thin limbs (DTLs), ascending thin limbs (ATLs), and collecting ducts (CDs) were identified with antibodies against segment-specific proteins. DTLs are distributed nonuniformly in transverse sections of papilla, but lateral compartmentation between DTLs and CD clusters that occurs in outer IM makes no contribution to concentrating mechanism in papilla. ATLs are distributed nearly uniformly throughout IM. Vasa recta within ∼2 mm of the papilla tip are primarily fenestrated vessels; therefore, AVR and DVR can only be determined by blood flow direction. CDs within ∼500 μm of the papilla tip have nearly 100% greater circumference than CDs within first 1–2 mm below the IM base. Return of water to general circulation from deep papillary CDs appears to be facilitated by a 150% increase in the number of AVR closely abutting these CDs. Consequently, average fractional CD surface area abutting AVR is 0.61, about the same as that (0.54) for smaller CDs that lie near the IM base. Interstitial nodal compartments, bounded by CDs, ATLs, and AVR, surround CDs along the axis of the IM. Fewer ATLs exist in the final 1 mm, as there are fewer loops and the number of these nodal arrangements is therefore reduced. However, tips of many of those loops reaching this area have bends with 50–100% greater transverse lengths than bends of loops near the IM base. This may be significant for solute movement out of loop bends.
Proteomic analysis defines altered cellular redox pathways and advanced glycation end-product metabolism in glomeruli ofdb/dbdiabetic mice
Authors: Barati Michelle T. , Merchant Michael L. , Kain Angela B. , Jevans Anthony W. , McLeish Kenneth R. , Klein Jon B.
Published: July 2007

To attain a profile of protein expression during diabetes, we applied proteomic analysis to glomeruli of 160-day-old db/db diabetic and db/m nondiabetic mice. Glomerular proteins were extracted and separated by two-dimensional gel electrophoresis to construct a proteome map. Matrix-assisted laser desorption and ionization-time of flight mass spectrometry and peptide mass fingerprinting were used to identify 190 proteins. Of 105 analyzed spots, expression of 40 proteins, including the antioxidative enzymes peroxiredoxin 1 and 3, glutathione peroxidase 1, and SOD-1, was increased with diabetes, suggesting an adaptive response to oxidative stress associated with this diabetic model. However, activity of glutathione peroxidase and SOD was unaltered in glomeruli of diabetic mice. Expression of glyoxalase I was increased in glomeruli of diabetic mice. Because the cofactor for glyoxalase I, glutathione, is decreased in renal cortex of db/db mice, renal cortical glyoxalase I activity was measured in vitro with fixed amounts of exogenous glutathione. Glyoxalase I activity was decreased in renal cortex of db/db mice. These data indicate that diabetes-induced decreases in glyoxalase I activity are likely to be due to glutathione-dependent and -independent mechanisms and that increased expression of glyoxalase I may represent an insufficient adaptive response to increased methylglyoxal formation.
Characterization of ScAP-23, a new cell line from murine subcutaneous adipose tissue, identifies genes for the molecular definition of preadipocytes
Authors: Kim Ji Young , Wu Yu , Smas Cynthia M.
Published: July 2007

The 3T3-L1 model of in vitro adipogenesis has provided key insights into the molecular nature of this process. However, given that 3T3-L1 are of an embryonic origin, it is not clear to what extent they represent adipogenesis as it occurs in white adipose tissue (WAT). With the goal of better defining preadipocytes and adipogenesis in WAT, we have generated a new cell culture model from adipocyte precursors present in C57BL/6 mouse subcutaneous WAT. ScAP-23 preadipocytes show fibroblastic morphology, and on treatment with dexamethasone, 3-methylisobutylxanthine, insulin, and indomethacin, convert to nearly 100% adipocyte morphology. ScAP-23 adipocytes contain abundant lipid droplets and express transcripts for PPARγ, C/EBP family, and SREBP-1c transcription factors, SCD1, aFABP, ATGL, GLUT4, FAS, LDL, and GPDH, and are insulin responsive. Differential screening of 1,176 genes using nylon DNA arrays identified 10 transcripts enriched in ScAP-23 adipocytes vs. preadipocytes and 26 transcripts enriched in ScAP-23 preadipocytes vs. adipocytes. Semiquantitative or real-time PCR analyses identified a common cohort of 14 transcripts markedly downregulated in both ScAP-23 and 3T3-L1 adipogenesis. These included catenin-β1, chemokine ligand-2, serine or cysteine peptidase inhibitor f1, aurora kinase B, thrombospondin2, and solute carrier-7a5. Five of these transcripts (Ccl2, Serpinf1, Aurkb, Thbs2, and Slc7a5) demonstrated at least a twofold increase in WAT from obese ( ob/ob) mice compared with that of wild-type mice. This suggests that comparative gene expression studies of ScAP-23 and 3T3-L1 adipogenesis may be particularly fruitful in identifying preadipocyte-expressed genes that play a role in adipose tissue physiology and/or pathophysiology.
Nanobiotechnology-Based Drug Delivery to the Central Nervous System
Authors: Jain K.K.
Published: July 2007

Background: Drug delivery across the blood-brain barrier (BBB) is a major limitation in the treatment of central nervous system (CNS) disorders. Several approaches are being investigated to improve drug delivery across the BBB. Objective/Methods: This review deals with the role of nanobiotechnology in CNS drug delivery. The small size of the nanoparticles enables them to penetrate the BBB and facilitate the delivery of drugs across the barrier. Several mechanisms are involved in this process and various strategies are used based on different types of nanomaterial and combinations with therapeutic agents. Examples are given of the use of liposomes and polymeric nanoparticles. Results: Nanoparticles can be used as nonviral vectors for CNS gene therapy. Although the use of nanotechnology is expected to reduce the need for invasive procedures for delivery of therapeutics to the CNS, some devices such as implanted catheters and reservoirs will still be needed. Nanomaterials can improve the safety and efficacy of such devices. Nano-engineered probes can deliver drugs at the cellular level using nanofluidic channels. There is some concern about the safety of nanoparticle entry in the brain and this needs to be resolved before human use. Conclusion: Although there is no approved nanotechnology-based CNS drug as yet that incorporates nanobiotechnology, the future for such developments is promising.
Combined Therapies in the Treatment of Neurotrauma: Polymers, Bridges and Gene Therapy in Visual System Repair
Authors: Harvey Alan R.
Published: July 2007

Background: The mature central nervous system (CNS) has limited capacity for self-renewal and repair after injury or neurodegeneration, and therapeutic strategies are needed to promote the viability of damaged neurons and the regrowth of their axons. The retina and optic nerve (ON) are part of the CNS, and the visual system is widely used in experimental studies on injury and repair. Objective:To test various cellular and molecular approaches in attempts to replace retinal ganglion cells (RGCs) in depleted retinas or, more usually, promote the survival of endogenous injured RGCs and stimulate axonal regeneration after ON or intracranial optic tract (OT) injury. Methods and Results: Intraocular injections of brain-derived neurotrophic factor and ciliary neurotrophic factor (CNTF) temporarily increase RGC survival after ON injury. More sustained neuroprotection is obtained using adeno-associated viral vectors to transfect RGCs with brain-derived neurotrophic factor or CNTF genes. After ON crush, intravitreal adeno-associated viral CNTF injections also increase RGC axonal regrowth. Additional protective and growth effects are obtained after intraocular elevation of cAMP and by manipulation of protein kinase signalling pathways in RGCs. Regeneration is increased by transplanting a segment of peripheral nerve onto the cut ON. Schwann cells in peripheral nerve grafts can be genetically modified using lentiviral vectors to over-express CNTF, resulting in increased regrowth of RGC axons. After OT lesions, hydrogels have been used to bridge the injury, sometimes with the incorporation of signalling peptides or cells genetically modified to express neurotrophic factors. Conclusions: There is now a general consensus that combinatorial approaches are needed to elicit sustained and effective regenerative responses in injured adult CNS neurons.
Fate Determinant Expression in the Lesioned Brain: Olig2 Induction and Its Implications for Neuronal Repair
Authors: Buffo Annalisa
Published: July 2007

Although stem cells persist in restricted regions of the adult mammalian central nervous system (CNS), replacement of neurons does not take place in most regions in intact conditions or after injury. In the last years, proliferative multipotent cells have been isolated from the parenchyma of many CNS regions considered constitutively nonneurogenic, suggesting that the nonneurogenic CNS parenchyma is endowed with a latent neurogenic potential that might be exploited for neuronal replacement. However, neurogenic fate determinants acting during development and in the germinative zones are not expressed in the intact brain and after lesion, thus arguing against the presence of neurogenic competence in parenchymal precursors. Conversely, the basic helix-loop-helix transcription factor Olig2 is widely expressed in subsets of glia cells and progenitors, and it is strongly induced at different sites by both acute and chronic injury, albeit with different mechanisms. Antagonizing Olig2 function in cells proliferating after an acute lesion leads to the upregulation of the neurogenic determinant Pax6 and results in a significant number of newly generated immature neurons. Therefore, Olig2 acts as a repressor of neurogenesis in cells reacting to brain injury. Finding the proper way to fully derepress the neurogenic determinants in these cells, together with providing favorable environmental signals, may represent an effective approach towards evoking neuronal repair from parenchymal precursors.
A Wnt Signal Regulates Stem Cell Fate and Differentiation in vivo
Authors: Prakash Nilima , Wurst Wolfgang
Published: July 2007

Our knowledge about the normal generation of midbrain dopaminergic neurons in vivois still rudimentary, despite many attempts to recapitulate the underlying events in vitro. Because the loss of these neurons is implicated in Parkinson’s disease, this lack of information is one of the major drawbacks in the development of better therapies for this severe human neurological disorder. Recently, substantial advances have been made by demonstrating that the secreted molecule Wnt1 regulates a genetic network, including the transcription factors Otx2 and Nkx2-2, for the initial establishment of the dopaminergic progenitor domain in the mammalian ventral midbrain. In addition, Wnt1 appears to regulate the differentiation of the postmitotic progeny of these precursors by initiating the expression of midbrain dopaminergic-specific transcription factors. A genetic cascade controlled by the secreted molecule Sonic hedgehog, including the transcription factors Lmx1a, Msx1 and Nkx6-1, acts in parallel with the Wnt1-regulated network to establish the midbrain dopaminergic progenitor domain. The Sonic-hedgehog-controlled cascade may diverge from the Wnt1-regulated network at later stages of neural development through induction of proneural transcription factors required for the acquisition of generic neuronal properties by the midbrain dopaminergic progeny. Here we provide a brief overview of these regulatory gene networks.
Stem-Cell-Based Strategies for the Treatment of Parkinson’s Disease
Authors: Parish Clare L. , Arenas Ernest
Published: July 2007

Background: Cell transplantation to replace lost neurons in neurodegenerative diseases such as Parkinson’s disease (PD) offers a hopeful prospect for many patients. Previously, fetal grafts have been shown to survive, integrate and induce functional recovery in PD patients. However, limited tissue availability has haltered the widespread use of this therapy and begs the demand for alternative tissue sources. In this regard, stem cells may constitute one such source. Objective/Methods: In this review we outline various types of stem cells currently available and provide an overview of their possible application for PD. We address not only the obvious possibility of using stem cells in cell replacement therapy but also the benefits of stem cell lines in drug discovery. Results/Conclusion: Stem cells carrying reporters or mutations in genes linked to familial PD are likely to contribute to the identification of new drug targets and subsequent development of new drugs for PD. Thus, stem cells are, and will be more so in the future, invaluable tools in the quest for new therapies against neurodegenerative diseases such as PD.
Evolutionary History of Sex-Linked Mammalian Amelogenin Genes
Authors: Iwase Mineyo , Kaneko Satoko , Kim Hielim , Satta Yoko , Takahata Naoyuki
Published: July 2007

Amelogenin (AMEL) arose prior to the emergence of tetrapods and transposed into an intron of the Rho GTPase-activating protein 6 gene. In the mammalian lineage leading to eutherians, a pair of homologous autosomes with this nested gene structure fused with the then already differentiating sex chromosomes by suppressing homologous recombination. As sex-chromosomal differentiation extended to the fused region, a pair of homologous AMEL genes too differentiated from each other in two steps; first in the 5′ region (the promoter region to transposon MER5 in intron 2) and second in the remaining 3′ region. This resulted in gametologous AMELX and AMELY in the eutherian sex chromosomes. Although the early differentiation of the 5′ region between AMELX and AMELY is consistent with the lowered expression level of AMELY, there is no indication for deterioration of AMELY at the amino acid level. Rather, both AMELX and AMELY in particular lineages might undergo positive selection, followed by negative selection to preserve established function. Based on patterns and levels of AMELX and AMELY polymorphisms in the human population, it is also argued that a recombination cold spot near AMELX might be related to the cause of the ancient pseudoautosomal boundary.
Unraveling the Molecular Mechanisms That Lead to Supernumerary Teeth in Mice and Men: Current Concepts and Novel Approaches
Authors: D’Souza Rena N. , Klein Ophir D.
Published: July 2007

Supernumerary teeth are defined as those that are present in excess of the normal complement of human dentition and represent a unique developmental anomaly of patterning and morphogenesis. Despite the wealth of information generated from studies on normal tooth development, the genetic etiology and molecular mechanisms that lead to congenital deviations in tooth number are poorly understood. For developmental biologists, the phenomenon of supernumerary teeth raises interesting questions about the development and fate of the dental lamina. For cell and molecular biologists, the anomaly of supernumerary teeth inspires several questions about the actions and interactions of transcription factors and growth factors that coordinate morphogenesis, cell survival and programmed cell death. For human geneticists, the condition as it presents itself in either syndromic or non-syndromic forms offers an opportunity to discover mutations in known or novel genes. For clinicians faced with treating the dental complications that arise from the presence of supernumerary teeth, knowledge about the basic mechanisms involved is essential. The purpose of this manuscript is to review current knowledge about how supernumerary teeth form, the molecular insights gained through studies on mice that are deficient in certain tooth signaling molecules and the questions that require further research in the field.
Disorders of Human Dentin
Authors: Hart P. Suzanne , Hart Thomas C.
Published: July 2007

Dentin, the most abundant tissue in teeth, is produced by odontoblasts, which differentiate from mesenchymal cells of the dental papilla. Dentinogenesis is a highly controlled process that results in the conversion of unmineralized predentin to mineralized dentin. By weight, 70% of the dentin matrix is mineralized, while the organic phase accounts for 20% and water constitutes the remaining 10%. Type I collagen is the primary component (>85%) of the organic portion of dentin. The non-collagenous part of the organic matrix is composed of various proteins, with dentin phosphoprotein predominating, accounting for about 50% of the non-collagenous part. Dentin defects are broadly classified into two major types: dentinogenesis imperfectas (DIs, types I–III) and dentin dysplasias (DDs, types I and II). To date, mutations in DSPP have been found to underlie the dentin disorders DI types II and III and DD type II. With the elucidation of the underlying genetic mechanisms has come the realization that the clinical characteristics associated with DSPP mutations appear to represent a continuum of phenotypes. Thus, these disorders should likely be called DSPP-associated dentin defects, with DD type II representing the mild end of the phenotypic spectrum and DI type III representing the severe end.
Hepatocellular Injury of Nonischemic Liver Tissue after Selective Clamping in Rats – Protective Action by Pharmacological Pretreatment with Lipoic Acid
Authors: Duenschede F. , Westermann S. , Miesner I. , Albrecht-Schöck S. , Kneist W. , Korenkov M. , Schad A. , Dutkowski Ph. , Kiemer A.K. , Junginger T.
Published: July 2007

Background/Aim: The aim of the study was to characterize the hepatic injury (HI) of the nonischemic liver lobe after selective portal triad clamping and investigate the influence of pharmacological pretreatment with α-lipoic acid (LA). Methods: Brown-Norway rats received 500 µmol LA injected via the inferior vena cava 15 min prior to the induction of 90 min of selective ischemia. Another group of rats received vehicle prior to ischemia. Both groups were compared with sham-operated animals. Results: Lipid peroxidation (LPO) was increased in the ischemic as well as in the nonischemic liver tissue () in the untreated group. Levels of adenosine triphosphate and reduced glutathione content of the nonischemic liver lobe were decreased in the untreated group 1 h after reperfusion. Activity of caspases 3 and 8 was not detectable, whereas expression of the Bax protein was demonstrated in the . We observed areas of necrotic hepatocytes and large gaps of sinusoids in the of the untreated rats. LA attenuated LPO as well as Bax expression in the . Moreover adenosine triphosphate and glutathione content of the was increased 1 h after reperfusion by LA. LA pretreatment reduced release of α-glutathione-s-transferase in plasma. Histology of the nonischemic liver lobe did not markedly differ from sham-operated animals after LA pretreatment. Conclusion: HI of the seems to be mediated by LPO and proapoptotic proteins such as Bax. Besides its described potential to reduce ischemia/reperfusion injury of the ischemic lobe, LA attenuates HI of the nonischemic tissue after selective portal triad clamping.
Evolution and Variation of the H3 Gene of Influenza A Virus and Interaction among Hosts
Authors: Zhang Wentong , Jiang Qingwu , Chen Yue
Published: July 2007

Objective: Continual mutations to the hemagglutinin (HA) gene of influenza A virus generate novel antigenic strains that cause annual epidemics. The aim of this study was to evaluate evolution tendency of the H3 gene in a long period of time. Methods: 1842 H3 HA1 nucleotide strains of different hosts were collected for analysis. A two-step clustering method was used to divide strains into groups, and then a phylogenetic tree was constructed based on cluster results. Evolution rate in lineages were future estimated. Results: Tree structure showed three lineages: horse/canine, human/swine and avian. As a single trunk, the human/swine lineage was mainly composed of human strains, and more big branches appeared in recent years. Tree topology showed no evidence that swine affected the main evolution tendency of human H3 strains. The evolution rate of H3 strains varied between lineages. We observed that the rate in the human lineage decreased from 3.2 substitutions/year before 1980 to 1.8 after 1997. Conclusion: We concluded that the variation of human H3 gene was associated with swine strains but independent of others, including bird strains. The evolution rate of human H3 strains seems to have decreased in recent years, while the reasons for the rate change need to be further explored.
Development and Psychometric Properties of the Ambulatory Self-Confidence Questionnaire
Authors: Asano Miho , Miller William C. , Eng Janice J.
Published: July 2007

Background: Ambulation is one of the most important elements of mobility, and difficulty with ambulation is often cited as a common problem among older adults. Self-report assessments (e.g. walking confidence) provide complementary information to performance tests (e.g. the Timed Up and Go Test, TUG) because they offer data not obtainable from a test of walking performance. Objective: To develop and assess the reliability and the content and construct validity of the Ambulatory Self-Confidence Questionnaire (ASCQ), a new measure of walking confidence. Methods: This descriptive methodological study used data from two samples. The first sample included 31 individuals (13 community-dwelling older adults, aged 65 years and older and 18 academics, clinicians, and researchers working in the area of ambulatory care and geriatrics and medicine) who assisted in establishing the content validity. Participants were asked to complete two surveys to assess the content of the ASCQ. For the second sample 101 community-dwelling older adults (≧65 years old) were recruited, from community centers, senior day centers, and geriatric clinics in order to determine the reliability and construct validity of the ASCQ. The ASCQ was completed twice over a 2-week interval while other measures such as the TUG, the 6-Min Walk Test (6MWT), the Activities-specific Balance Confidence scale (ABC) and the Instrumental Activities of Daily Living scale (IADL) were completed once in order to assess validity. Results: Group consensus was obtained for a 22-item version of the ASCQ. Of the 101 participants recruited for the project, 67 provided complete information for test-retest reliability and 91 provided information for assessment of validity. Internal consistency (Cronbach’s α = 0.95) and test-retest reliability (ICC1.1 = 0.92; 95% confidence interval (CI) 0.87, 0.95) were excellent. The ASCQ was: (1) highly correlated with the ABC scale (ρ = 0.87); moderately correlated with the TUG (ρ = –0.46) and the 6MWT (ρ = 0.36); and weakly correlated with the IADL (ρ = 0.27). Conclusion: The ASCQ is reliable and support for validity is evident for this sample of community-dwelling older adults. Further studies are needed to assess the reliability and validity in a frailer older adult sample. The ASCQ may be useful to clinicians and researchers alike for determining an older adult’s confidence with their walking ability.
Low-Power Transpupillary Thermotherapy Combined with Intravitreal Triamcinolone Acetonide for Subfoveal Choroidal Neovascularization
Authors: Zhang Xinyuan , Zhu Xiaoqing , Wang Dongsheng , Xu Liang , Jonas Jost B.
Published: July 2007

Purpose: To examine transpupillary thermotherapy combined with intravitreal triamcinolone for treatment of subfoveal choroidal neovascularization. Methods: The clinical interventional, noncomparative, case series study included 14 patients (14 eyes) with choroidal neovascularization (age-related macular degeneration, n = 11; high myopia, n = 2; unknown reason, n = 1), who underwent transpupillary thermotherapy (75–150 mW, 60 s, 500–3,000 µm), followed by an intravitreal triamcinolone injection (10 mg). Follow-up was at least 6 months. Results: Visual acuity increased by 3 lines in 3 (21%) eyes at 3 months, and in 3 (21%) eyes at 6 months of follow-up. None of the patients experienced a visual acuity loss of 3 or more lines. At the 6-month follow-up, mean visual acuity was improved by 1.36 ± 1.16 lines. Retreatment by transpupillary thermotherapy was performed for 3 (21%) eyes at 3 months, and for 1 (7%) eye at 6 months of follow-up. Conclusions: Transpupillary thermotherapy combined with intravitreal triamcinolone may be a therapeutic option for choroidal neovascularization particularly if other treatment modalities are not available.
EF6265, a Novel Plasma Carboxypeptidase B Inhibitor, Protects against Renal Dysfunction in Rat Thrombotic Glomerulonephritis through Enhancing Fibrinolysis
Authors: Muto Yuko , Suzuki Kokichi , Iida Hiroyuki , Ishii Hidemi
Published: July 2007

Background/Aim: Plasma carboxypeptidase B is a physiological fibrinolysis inhibitor. In the present study, the effects of EF6265, a novel specific plasma carboxypeptidase B inhibitor, on renal dysfunction in a rat thrombotic glomerulonephritis model were examined. Methods: The model was induced by injection of anti-glomerular basement membrane serum and lipopolysaccharide to rats. Renal microthrombosis was histologically evaluated by phosphotungstic acid-hematoxylin staining for fibrin thrombi. Renal dysfunction was evaluated on the basis of plasma levels of blood urea nitrogen as well as renal edemas and urine volume. Results: The glomerular microthrombi observed in a positive control group were significantly reduced after a short-term treatment (4 h) with EF6265 at a dose which enhanced fibrinolysis. The elevation of blood urea nitrogen and renal edema formation decreased, and the reduction of the urine volume improved after a long-term treatment (21 h) with EF6265. In addition, EF6265 had a protective activity against multiple organ dysfunction, because it reduced plasma lactate dehydrogenase and alanine aminotransferase levels and mortality in this model. Conclusion: EF6265, which inhibits plasma carboxypeptidase B, showed a protective effect on thrombotic renal dysfunction in thrombotic glomerulonephritis through enhancing the fibrinolysis.
Memantine (Ebixa®) in Clinical Practice – Results of an Observational Study
Authors: Calabrese Pasquale , Essner Ute , Förstl Hans
Published: July 2007

Background/Aims: In a post-marketing observational study, the efficacy and tolerability of memantine were examined in patients with moderate to severe Alzheimer’s disease. Methods: The patients were treated with 20 mg/day of memantine for a 6-month period. The efficacy of memantine was evaluated using the Mini-Mental State Examination, the Nurses’ Observation Scale for Geriatric Patients (NOSGER) and the Explorationsmodul Demenz (EMD) scale. In addition, a global assessment was made by the physician. Results: After 6 months of open-label treatment with memantine, the patients’ cognitive function, ability to perform daily activities and global performance all showed a marked improvement. In the overall evaluation by the physician, improvement or stabilisation had been achieved by 78.8% of patients after 6 months of therapy. Memantine also demonstrated an excellent tolerability profile. Conclusion: The results of this naturalistic study support the significant efficacy and tolerability of memantine that has been previously demonstrated in randomised, controlled clinical Alzheimer’s disease trials.
TGF-β1 and TSC-22 Gene Polymorphisms and Susceptibility to Microvascular Complications in Type 2 Diabetes
Authors: Buraczynska Monika , Baranowicz-Gaszczyk Iwona , Borowicz Ewa , Ksiazek Andrzej
Published: July 2007

Background/Aim: There is a strong evidence for the involvement of genetic factors in diabetic microvascular complications. The aim of our study was to investigate the role of molecular variants of the TGF-β1 (transforming growth factor beta 1) and the TSC-22 (transforming growth factor beta stimulated clone 22) genes in diabetic nephropathy and diabetic retinopathy in type 2 diabetes. Methods: A case-control study was conducted in 503 patients and 400 healthy subjects. DNA samples were genotyped by polymerase chain reaction and restriction fragment length polymorphism methods. Results: Among the patients, 245 had diabetic nephropathy, 195 had retinopathy, and 168 were free from complications. All subjects were genotyped for T869C and C –509T polymorphisms of the TGF-β1 gene and for –396 polymorphism of the TSC-22 gene. A significantly increased frequency of the CC genotype of the T869C polymorphism was observed in patients with nephropathy and retinopathy (33 and 48%, respectively, vs. 19 and 15%, respectively, in controls and patients free from complications). The frequency of the C allele was also higher (0.58 for nephropathy and 0.64 for retinopathy vs. 0.42 in controls). The G allele of the TSC-22 polymorphism was associated with an increased risk of diabetic nephropathy (frequency 0.15 vs. 0.07 and 0.06, respectively, in patients free from complications and controls). An interaction was observed between the G allele of the TSC-22 polymorphism and the C-allele of the TGF-β polymorphism. Conclusions: Our data suggest the association of TGF-β T869C gene polymorphism with an increased risk of nephropathy and retinopathy in type 2 diabetes patients. It interacts with the TSC-22 gene involved in the TGF-β signaling pathway, promoting the development of diabetic nephropathy.
Differential Inhibition of Renin mRNA Expression by Paricalcitol and Calcitriol in C57/BL6 Mice
Authors: Fryer Ryan M. , Rakestraw Pamela A. , Nakane Masaki , Dixon Doug , Banfor Patricia N. , Koch Kristin A. , Wu-Wong J. Ruth , Reinhart Glenn A.
Published: July 2007

Background/Aims: Vitamin D receptor activators (VDRAs) may suppress renin expression and VDR-mediated renin inhibitors may offer a novel mechanism to control the RAS. Methods: We delineated the effects of paricalcitol and calcitriol on PTH, renin, and iCa2+ in C57/BL6 mice administered vehicle, paricalcitol, or calcitriol (0.01, 0.03, 0.10, 0.33, 1.0 µg/kg s.c.) 3 days/week for 9 days. Results: Paricalcitol produced PTH suppression from 0.03 to 1.0 µg/kg (values between 9.7 ± 3.3 and 20.7 ± 4.7 pg/ml; vehicle = 88.0 ± 16.9) and elicited dose-dependent reductions in renin/GAPDH expression at 0.33 and 1.0 µg/kg (0.037 ± 0.002, 0.027 ± 0.003; vehicle = 0.054 ± 0.003) but produced no increases iCa2+ at any dose tested. Calcitrol produced PTH suppression at all doses tested (between 6.4 ± 1.2 and 29.5 ± 17.2 pg/ml) and renin suppression at 0.10, 0.33, and 1.0 µg/kg (0.029 ± 0.002, 0.031 ± 0.003, and 0.038 ± 0.02). However, at 0.33 and 1.0 mg/kg, calcitriol produced increases iCa2+ (1.31 ± 0.03 and 1.48 ± 0.02 mmol/l; vehicle = 1.23 ± 0.02 mmol/l). Conclusions: Paricalcitol produces significant, dose-dependent suppression of renin expression in the absence of hypercalcemia at doses 10-fold above those necessary for PTH suppression. Calcitriol also produced suppression of renin at doses at least 10-fold above those required for PTH suppression, but increases in iCa2+ were observed at doses only 3-fold above those necessary to elicit renin suppression.
Intrarenal Cytokine and Chemokine Gene Expression and Kidney Graft Outcome
Authors: Hribova Petra , Lacha Jiri , Kotsch Katja , Volk Hans-Dieter , Brabcova Irena , Skibova Jelena , Vitko Stefan , Viklicky Ondrej
Published: July 2007

Aims: Proinflammatory cytokines are thought to play an important role in various kidney graft diseases resulting in interstitial fibrosis and tubular atrophy frequently found in case biopsies. To explore the role of various cytokines and chemokines in the long-term graft outcome, the transcription patterns of their genes in kidney allograft biopsies were evaluated. Methods: The real-time RT-PCR was used to identify intragraft mRNA expression of cytokines and chemokines in 74 kidney graft recipients and the results were correlated with histological and clinical parameters and long-term graft outcome. Results: We observed up-regulated IL-10 (p < 0.001), TGF-β1, IL-6, MCP-1, RANTES (p < 0.01) and TNF-α (p < 0.05) mRNA expression in patients with chronic allograft nephropathy (CAN) as compared to controls. There were positive correlations between the mRNA expression of IL-6 (p < 0.001), IL-10 (p < 0.01), TNF-α, MCP-1 (p < 0.05) and the proteinuria. The up-regulation of intrarenal MCP-1 in patients with CAN increased the risk for the graft failure within the next 42 months (OR 5.1, p < 0.05). Kaplan-Meier survival analysis revealed that proteinuria and higher intragraft expression of TGF-β1 and MCP-1 predict a poor kidney graft outcome. Conclusion: Expression patterns of intrarenal proinflammatory genes might discriminate patients at a higher risk for the earlier allograft failure.
Analysis of the Effect of Memantine in Reducing the Worsening of Clinical Symptoms in Patients with Moderate to Severe Alzheimer’s Disease
Authors: Wilkinson David , Andersen Henning Friis
Published: July 2007

Background: Alzheimer’s disease (AD) is a progressive neurodegenerative disorder and delaying disease worsening is a relevant treatment outcome. Methods: Data from 6 randomized, double-blind, placebo-controlled, 6-month studies were pooled and a subgroup of patients (867 on placebo, 959 on memantine) with moderate to severe AD (Mini- Mental State Examination <20) was analyzed. ‘Any clinical worsening’ was defined as a decline on the Alzheimer’s Disease Assessment Scale – Cognitive Subscale (ADAS-cog) or the Severe Impairment Battery (SIB) and on the Clinician’s Interview-Based Impression of Change Plus Caregiver Input (CIBIC-plus) and the Alzheimer’s Disease Cooperative Study – Activities of Daily Living Inventory (ADCS-ADL), and ‘marked clinical worsening’ as ≧4 points decline on the ADAS-cog or ≧5 points on the SIB and decline on the CIBIC-plus and the ADCS-ADL. Results: More placebo-treated than memantine-treated patients showed any clinical worsening (28 vs. 18%; p < 0.001), and 21% placebo-treated patients compared to 11% memantine-treated patients had marked clinical worsening (p < 0.001). Conclusion: In this population of moderate and severe AD patients, treatment with memantine was associated with reducing worsening of clinical symptoms in AD during the 6-month study period.
Impact of Different Sampling Strategies on Score Results of the Nine Equivalents of Nursing Manpower Use Score (NEMS)
Authors: Junger A. , Klasen J. , Brenck F. , Röhrig R. , Hempelmann G. , Hartmann B.
Published: July 2007

Objective:
Prospective observational study to assess the impact of two differentsampling strategies on the score results of the NEMS, used widely to estimate the amount of nursing workload in an ICU.

Methods:
NEMS scores of all patients admitted to the surgical ICU over a one-year period were automatically calculated twice a day with a patient data management system for each patient day on ICU using two differentsampling strategies (NEMSindividual: 24-hour intervals starting from the time of admission; NEMS8a.m.: 24-hour intervals starting at 8 a.m.).

Results:
NEMSindividual and NEMS8a.m. were collected on 3236 patient days; 687 patients were involved. Significantly lower scores were found for the NEMS8a.m. (25.0 ± 8.7) compared to the NEMSindividual (26.1 ± 8.9, p <0.01); the interclass correlation coefficient (ICC) was good but not excellent: 0.78. The inter-rater correlation between the two NEMS scores was high or very high (κ = 0.6-1.0) for six out of nine variables of the NEMS.

Conclusions:
Different sampling strategies produce different score values, especiallydueto the end of stay. This has to betaken into accountwhen using the NEMS in quality assurance projects and multi-center studies.