bluuebunny/crossref_metadata_2025 huggingface dataset:
Urothelial expression of neuropilins and VEGF receptors in control and interstitial cystitis patients
Authors: Saban Ricardo , Saban Marcia R. , Maier Julie , Fowler Ben , Tengowski Mark , Davis Carole A. , Wu Xue-Ru , Culkin Daniel J. , Hauser Paul , Backer Joseph , Hurst Robert E.
Published: September 2008

Interstitial cystitis (IC) is a chronic and painful bladder syndrome of unknown cause with no reliable biological marker or effective therapy. Vascular endothelial growth factor (VEGF), which plays a key role in bladder inflammation, is closely associated with the vascular alterations observed in patients with IC. However, our recent findings of VEGF receptors (VEGF-Rs) and VEGF coreceptors on nonendothelial cells in human and mouse urothelium suggest that additional VEGF targets and functions are possible in IC bladders. We report here that VEGF-Rs and coreceptors (neuropilins; NRP) are strongly expressed in both the human bladder urothelium and in the human bladder cancer cell line (J82) and that the expression of NRP2 and VEGF-R1 is significantly downregulated in IC compared with control subjects. In addition, treatment of J82 cells with bacillus Calmette-Guérin (BCG), a novel treatment strategy for IC, upregulates the messages for NRPs and VEGF-Rs. Furthermore, intravesical instillation of an internalizable VEGF fluorescent tracer (scVEGF/Cy5.5) into mouse urinary bladders results in a marked ligand accumulation in the urothelium and bladder parenchyma, indicating that urothelial VEGF-Rs are functionally active and capable of ligand interaction and internalization. Our results suggest that the VEGF pathway is altered in IC, that urinary VEGF may gain access to the bladder wall via these receptors, and that BCG treatment may replenish the missing VEGF-Rs/NRP receptors. Together, these results suggest that levels of NRPs, VEGF-Rs, and VEGF are new putative markers for the diagnosis of IC and that modulating these receptors can be exploited as therapeutic strategies.
Delayed Synaptic Transmission in Drosophila cacophonynull Embryos
Authors: Hou Jiamei , Tamura Takuya , Kidokoro Yoshiaki
Published: September 2008

Ca2+ influx through the Drosophila N-type Ca2+ channel, encoded by cacophony ( cac), triggers fast synaptic transmission. We now ask whether the cac Ca2+ channel is the Ca2+ channel solely dedicated for fast synaptic transmission. Because the cac null mutation is lethal, we used cac null embryos to address this question. At the neuromuscular junction in HL3 solution, no fast synchronous synaptic transmission was detected on nerve stimulation. When the wild-type cac gene was introduced in the cac null background, fast synaptic transmission recovered. However, even in cac null embryos, nerve stimulation infrequently induced delayed synaptic events in the minority of cells in 1.5 mM [Ca2+]e and in the majority of cells in 5 mM [Ca2+]e. The number of delayed quantal events per stimulus was greater in 5 mM [Ca2+]e than in 1.5 mM. Thus the delayed release is [Ca2+]e dependent. Plectreurys toxin II (PLTXII) (10 nM; a spider toxin analog) depressed the frequency of delayed events, suggesting that voltage-gated Ca2+ channels, other than cac Ca2+ channels, are contributing to them. However, delayed events were not affected by 50 μM La3+. The frequency of miniature synaptic currents in cac null embryos was ∼1/2 of control, whereas in high K+ solutions, it was ∼1/135. The hypertonicity response was ∼1/10 of control. These findings indicate that the number of release-ready vesicles is smaller in cac null embryos. Taken together, the cac Ca2+ channel is indispensable for fast synaptic transmission in normal conditions, and another type of Ca2+ channel, the non- cac, PLTXII-sensitive Ca2+ channel, is contributing to delayed release in cacnull embryos.
Conductances Mediating Intrinsic Theta-Frequency Membrane Potential Oscillations in Layer II Parasubicular Neurons
Authors: Glasgow Stephen D. , Chapman C. Andrew
Published: September 2008

Ionic conductances that generate membrane potential oscillations in neurons of layer II of the parasubiculum were studied using whole cell current-clamp recordings in horizontal slices from the rat brain. Blockade of ionotropic glutamate and GABA synaptic transmission did not reduce the power of the oscillations, indicating that oscillations are not dependent on synaptic inputs. Oscillations were eliminated when cells were hyperpolarized 6–10 mV below spike threshold, indicating that they are mediated by voltage-dependent conductances. Application of TTX completely eliminated oscillations, suggesting that Na+ currents are required for the generation of the oscillations. Oscillations were not reduced by blocking Ca2+ currents with Cd2+ or Ca2+-free artificial cerebrospinal fluid, or by blocking K+ conductances with either 50 μM or 5 mM 4-aminopyridine (4-AP), 30 mM tetraethylammonium (TEA), or Ba2+(1–2 mM). Oscillations also persisted during blockade of the muscarinic-dependent K+ current, IM, using the selective antagonist XE-991 (10 μM). However, oscillations were significantly attenuated by blocking the hyperpolarization-activated cationic current Ih with Cs+ and were almost completely blocked by the more potent Ih blocker ZD7288 (100 μM). Intrinsic membrane potential oscillations in neurons of layer II of the parasubiculum are therefore likely driven by an interaction between an inward persistent Na+ current and time-dependent deactivation of Ih. These voltage-dependent conductances provide a mechanism for the generation of membrane potential oscillations that can help support rhythmic network activity within the parasubiculum during theta-related behaviors.
Opioid Receptors on Bulbospinal Respiratory Neurons Are Not Activated During Neuronal Depression by Clinically Relevant Opioid Concentrations
Authors: Stucke Astrid G. , Zuperku Edward J. , Sanchez Antonio , Tonkovic-Capin Mislav , Tonkovic-Capin Viseslav , Mustapic Sanda , Stuth Eckehard A.
Published: September 2008

Opioids depress the activity of brain stem respiratory-related neurons, but it is not resolved whether the mechanism at clinical concentrations consists of direct neuronal effects or network effects. We performed extracellular recordings of discharge activity of single respiratory neurons in the caudal ventral respiratory group of decerebrate dogs, which were premotor neurons with a likelihood of 90%. We used multibarrel glass microelectrodes, which allowed concomitant highly localized picoejection of opioid receptor agonists or antagonists onto the neuron. Picoejection of the μ receptor agonist [d-Ala2, N-Me-phe4, gly-ol5]-enkephalin (DAMGO, 1 mM) decreased the peak discharge frequency (mean ± SD) of expiratory neurons to 68 ± 22% ( n = 12), the δ1 agonist d-Pen2,5-enkephalin (DPDPE, 1 mM) to 95 ± 11% ( n = 15), and δ2 receptor agonist [d-Ala2] deltorphin-II to 86 ± 17% (1 mM, n = 15). The corresponding values for inspiratory neurons were: 64 ± 12% ( n = 11), 48 ± 30% ( n = 12), and 75 ± 15% ( n = 11), respectively. Naloxone fully reversed these effects. Picoejection of morphine (0.01–1 mM) depressed most neurons in a concentration dependent fashion to maximally 63% ( n = 27). Picoejection of remifentanil (240–480 nM) did not cause any significant depression of inspiratory ( n = 11) or expiratory neurons ( n = 9). 4. Intravenous remifentanil (0.2–0.6 μg·kg−1·min−1) decreased neuronal peak discharge frequency to 60 ± 12% (inspiratory, n = 7) and 58 ± 11% (expiratory, n = 11). However, local picoejection of naloxone did not reverse the neuronal depression. Our data suggest that μ, δ1, and δ2 receptors are present on canine respiratory premotor neurons. Clinical concentrations of morphine and remifentanil caused no local depression. This lack of effect and the inability of local naloxone to reverse the neuronal depression by intravenous remifentanil suggest that clinical concentrations of opioids produce their depressive effects on mechanisms upstream from respiratory bulbospinal premotor neurons.
Selective Spike Propagation in the Central Processes of an Invertebrate Neuron
Authors: Evans Colin G. , Kang Timothy , Cropper Elizabeth C.
Published: September 2008

Within a neuron, spike propagation can occur in a complex manner, with spikes propagating into some processes but not others. We study this phenomenon in an experimentally advantageous mechanoafferent in Aplysia, neuron B21. B21 has two processes within the CNS. One is ipsilateral to the soma and is referred to as the lateral process. The second travels into the contralateral hemiganglion and is referred to as the contralateral process. Previously we characterized spike propagation to the lateral process, which is an output region that contacts follower motor neurons. Spikes fail to actively propagate to the lateral process when B21 is peripherally activated at its resting potential. This propagation failure can be relieved if the medial regions of B21 are centrally depolarized during peripheral activation. This study examines spike propagation to the contralateral process. We show that, unlike the lateral process, active spike propagation in the contralateral process occurs when B21 is peripherally activated at its resting membrane potential. Thus spike propagation occurs selectively, favoring the contralateral process. Interestingly, the contralateral process of one B21 is immediately adjacent to the medial region of the bilaterally symmetrical cell. The B21 neurons are electrically coupled, suggesting that spikes propagating in the contralateral process of one cell could modify propagation in the sister neuron. Consistent with this idea, we show that lateral process propagation failures observed when a single B21 is peripherally activated can be relieved by central coactivation of the contralateral cell. These results imply that stimuli that coactivate the B21 neurons bilaterally are more apt to generate afferent activity that is transmitted to followers than stimuli that activate one cell.
Weak Solutions in Elasticity of Dipolar Porous Materials
Authors: Marin Marin
Published: September 2008

The main aim of our study is to use some general results from the general theory
of elliptic equations in order to obtain some qualitative results in a concrete
and very applicative situation. In fact, we will prove the existence and uniqueness
of the generalized solutions for the boundary value problems in elasticity of initially
stressed bodies with voids (porous materials).
Pigment Melanin Scavenges Nitric Oxide In Vitro: Possible Relevance to Keloid Formation
Authors: Menter Julian M. , Eatman Danita , Bayorh Mohamed , Dawaghreh Ahmad M. , Willis Isaac
Published: September 2008

Recently, nitric oxide (NO) has been implicated in the formation of keloids, preferentially formed in dark-skinned persons, and we suspected that pigment melanin itself may play a direct role by adsorbing NO. We tested the ability of cuttlefish sepia melanin to scavenge (adsorb) NO, generated in situ by 2-(N.N Diethylamino) diazeneolate-2-oxide (DEA/NO), through a dialysis membrane. NO was measured as and by the Griess method and as by trapping experiments with the fluorogenic substrate 4,5-diaminofluorescein (DAF-2). Initial and concentrations were significantly lower in the test dialyzates than in controls. Scavenging of NO was rapid enough to compete with DAF adduct formation. Both analytical methods gave comparable results. Adsorbed NO and/or its oxidized products may undergo interactions with melanin, adsorbed , and/or dermal material that may lead to keloid formation.
Stabilization of Linear Sampled‐Data Systems by a Time‐Delay Feedback Control
Authors: García F. Ricardo , Aguirre Baltazar , Suárez Rodolfo
Published: September 2008

We consider one‐dimensional, time‐invariant sampled‐data linear systems with constant feedback gain, an arbitrary fixed time delay, which is a multiple of the sampling period and a zero‐order hold for reconstructing the sampled signal of the system in the feedback control. We obtain sufficient conditions on the coefficients of the characteristic polynomial associated with the system. We get these conditions by finding both lower and upper bounds on the coefficients. These conditions let us give both an estimation of the maximum value of the sampling period and an interval on the controller gain that guarantees the stabilization of the system.
Transient Heat Diffusion with Temperature‐Dependent Conductivity and Time‐Dependent Heat Transfer Coefficient
Authors: Moitsheki Raseelo J.
Published: September 2008

Lie point symmetry analysis is performed for an unsteady nonlinear heat
diffusion problem modeling thermal energy storage in a medium with a
temperature‐dependent power law thermal conductivity and subjected to a
convective heat transfer to the surrounding environment at the boundary
through a variable heat transfer coefficient. Large symmetry groups are admitted
even for special choices of the constants appearing in the governing
equation. We construct one‐dimensional optimal systems for the admitted
Lie algebras. Following symmetry reductions, we construct invariant solutions.
The Role of Obstetrician/Gynecologists in the Management of Hepatitis C Virus Infection
Authors: Gonik Bernard
Published: September 2008

Chronic infection with hepatitis C virus (HCV) is a major cause of liver disease-related death and is also the most frequent indication for liver transplantation in USA. Infected individuals can remain asymptomatic for 20 years or more, but they remain at risk for progressive liver disease. They also represent a potential source of infection for others. For reducing the future disease burden due to HCV, obstetrician/gynecologists and primary health care practitioners should be aware of the factors that promote HCV transmission: how to provide counseling and testing, and when specialist referral is needed.
Bounded and Periodic Solutions of Semilinear Impulsive Periodic System on Banach Spaces
Authors: Wang Jin Rong , Xiang X. , Wei W. , Chen Qian
Published: September 2008

A class of semilinear impulsive periodic system on Banach spaces is considered. First, we introduce the "Equation missing"-periodic PC-mild solution of semilinear impulsive periodic system. By virtue of Gronwall lemma with impulse, the estimate on the PC-mild solutions is derived. The continuity and compactness of the new constructed Poincaré operator determined by impulsive evolution operator corresponding to homogenous linear impulsive periodic system are shown. This allows us to apply Horn's fixed-point theorem to prove the existence of "Equation missing"-periodic PC-mild solutions when PC-mild solutions are ultimate bounded. This extends the study on periodic solutions of periodic system without impulse to periodic system with impulse on general Banach spaces. At last, an example is given for demonstration.
Have Changes in Systemic Treatment Improved Survival in Patients with Breast Cancer Metastatic to the Brain?
Authors: Nieder Carsten , Marienhagen Kirsten , Dalhaug Astrid , Norum Jan
Published: September 2008

Newly developed systemic treatment regimens might lead to improved survival also in the subgroup of breast cancer patients that harbour brain metastases. In order to examine this hypothesis, a matched pairs analysis was performed that involved one group of patients, which were treated after these new drugs were introduced, and one group of patients, which were treated approximately 10 years earlier. The two groups were well balanced for the known prognostic factors age, KPS, extracranial disease status, and recursive partitioning analysis class, as well as for the extent of brain treatment. The results show that the use of systemic chemotherapy has increased over time, both before and after the diagnosis of brain metastases. However, such treatment was performed nearly exclusively in those patients with brain metastases that belonged to the prognostically more favourable groups. Survival after whole-brain radiotherapy has remained unchanged in patients without further active treatment. It has improved in prognostically better patients and especially patients that received active treatment, where the 1-year survival rates have almost doubled. As these patient groups were small, confirmation of the results in other series should be attempted. Nevertheless, the present results are compatible with the hypothesis that improved systemic therapy might contribute to prolonged survival in patients with brain metastases from breast cancer.
Transthyretin and Amyloid in the Islets of Langerhans in Type‐2 Diabetes
Authors: Westermark Gunilla T. , Westermark Per
Published: September 2008

Transthyretin (TTR) is a major amyloid fibril protein in certain systemic forms of amyloidosis. It is a plasma protein, mainly synthesized by the liver but expression occurs also at certain minor locations, including the endocrine cells in the islets of Langerhans. With the use of immunohistochemistry and in situ hybridization, we have studied the distribution of transthyretin‐containing cells in islets of Langerhans in type‐2 diabetic and nondiabetic individuals. TTR expression was particularly seen in alpha (glucagon) cells. Islets from type‐2 diabetic patients had proportionally more transthyretin‐reactive islet cells, including beta cells. A weak transthyretin immunoreaction in IAPP‐derived amyloid occurred in some specimens. In seeding experiments in vitro, we found that TTR fibrils did not seed IAPP while IAPP fibrils seeded TTR. It is suggested that islet expression of transthyretin may be altered in type‐2 diabetes.
A Phase‐Locked Loop with 30% Jitter Reduction Using Separate Regulators
Authors: Lee Tzung-Je , Wang Chua-Chin
Published: September 2008

A phase‐locked loop (PLL) using separate regulators to reject the supply noise is proposed in this paper. Two regulators, REG1 and REG2, are used to prevent the supply noise from the charge pump (CP) and the voltage‐controlled oscillator (VCO), respectively. By using separate regulators, the area and the power consumption of the regulator can be reduced. Moreover, the jitter of the proposed PLL is proven on silicon to be less sensitive to the supply noise. The proposed PLL is fabricated using a typical 0.35 μm 2P4M CMOS process. The peak‐to‐peak jitter (P2P jitter) of the proposed PLL is measured to be 81.8 ps at 80 MHz when a 250 mVrms supply noise is added. By contrast, the P2P jitter is measured to be 118.2 ps without the two regulators when the same supply noise is coupled.
Cerebral Blood Flow Measurement Using fMRI and PET: A Cross‐Validation Study
Authors: Chen Jean J. , Wieckowska Marguerite , Meyer Ernst , Pike G. Bruce
Published: September 2008

An important aspect of functional magnetic resonance imaging (fMRI) is the study of brain hemodynamics, and MR arterial spin labeling (ASL) perfusion imaging has gained wide acceptance as a robust and noninvasive technique. However, the cerebral blood flow (CBF) measurements obtained with ASL fMRI have not been fully validated, particularly during global CBF modulations. We present a comparison of cerebral blood flow changes (ΔCBF) measured using a flow‐sensitive alternating inversion recovery (FAIR) ASL perfusion method to those obtained using H2 15O PET, which is the current gold standard for in vivo imaging of CBF. To study regional and global CBF changes, a group of 10 healthy volunteers were imaged under identical experimental conditions during presentation of 5 levels of visual stimulation and one level of hypercapnia. The CBF changes were compared using 3 types of region‐of‐interest (ROI) masks. FAIR measurements of CBF changes were found to be slightly lower than those measured with PET (averageΔCBF of 21.5 ± 8.2% for FAIR versus 28.2 ± 12.8% for PET at maximum stimulation intensity). Nonetheless, there was a strong correlation between measurements of the two modalities. Finally, at‐test comparison of the slopes of the linear fits of PET versus ASLΔCBF for all 3 ROI types indicated no significant difference from unity (P> .05).
Fine Control of Local Whitespace in Placement
Authors: Roy Jarrod A. , Papa David A. , Markov Igor L.
Published: September 2008

In modern design methodologies, a large fraction of chip area during placement is left unused by standard cells and allocated as “whitespace." This is done for a variety of reasons including the need for subsequent buffer insertion, as a means to ensure routability, signal integrity, and low coupling capacitance between wires, and to improve yield through DFM optimizations. To this end, layout constraints often require a certain minimum fraction of whitespace in each region of the chip. Our work introduces several techniques for allocation of whitespace in global, detail, and incremental placement. Our experiments show how to efficiently improve wirelength by reallocating whitespace in legal placements at the large scale. Additionally, for the first time in the literature, we empirically demonstrate high‐precision control of whitespace in designs with macros and obstacles. Our techniques consistently improve the quality of whitespace allocation of top‐down as well as analytical placement methods and achieve low penalties on designs from the ISPD 2006 placement contest with minimal interconnect increase.
Synthesis and Optical Properties of Au‐Ag Alloy Nanoclusters with Controlled Composition
Authors: Sánchez-Ramírez J. F. , Pal U. , Nolasco-Hernández L. , Mendoza-Álvarez J. , Pescador-Rojas J. A.
Published: September 2008

Colloidal solid‐solution‐like Au‐Ag alloy nanoclusters of different compositions were synthesized through citrate reduction of mixed metal ions of low concentrations, without using any other protective or capping agents. Optical absorption of the alloy nanoclusters was studied both theoretically and experimentally. The position of the surface plasmon resonance (SPR) absorption band of the nanoclusters could be tuned from 419 nm to 521 nm through the variation of their composition. Considering effective dielectric constant of the alloy, optical absorption spectra for the nanoclusters were calculated using Mie theory, and compared with the experimentally obtained spectra. Theoretically obtained optical spectra well resembled the experimental spectra when the true size distribution of the nanoparticles was considered. High‐resolution transmission electron microscopy (HREM), high‐angle annular dark field (HAADF) imaging, and energy dispersive spectroscopy (EDS) revealed the true alloy nature of the nanoparticles with nominal composition being preserved. The synthesis technique can be extended to other bimetallic alloy nanoclusters containing Ag.
Neonatal and Infantile Immune Responses to Encapsulated Bacteria and Conjugate Vaccines
Authors: Klein Klouwenberg Peter , Bont Louis
Published: September 2008

Encapsulated bacteria are responsible for the majority of mortality among neonates and infants. The major components on the surface of these bacteria are polysaccharides which are important virulence factors. Immunity against these components protects against disease. However, most of the polysaccharides are thymus-independent (TI)-2 antigens which induce an inadequate immune response in neonates and infants. The mechanisms that are thought to play a role in the unresponsiveness of this age group to TI-2 stimuli will be discussed. The lack of immune response may be overcome by conjugating the polysaccharides to a carrier protein. This transforms bacterial polysaccharides from a TI-2 antigen into a thymus-dependent (TD) antigen, thereby inducing an immune response and immunological memory in neonates and infants. Such conjugated vaccines have been shown to be effective against the most common causes of invasive disease caused by encapsulated bacteria in neonates and children. These and several other approaches in current vaccine development will be discussed.
Identifying Usability and Productivity Dimensions for Measuring the Success of Mobile Business Services
Authors: Vuolle Maiju , Aula Anne , Kulju Minna , Vainio Teija , Wigelius Heli
Published: September 2008

This paper reviews existing measures used for evaluating the usability of information systems and those used for evaluating the level of the productivity of a company. We discuss the usefulness of the existing measures in the mobile business context, where both mobility and work-context pose specific demands for the mobile business services. The review showed that the existing measures rarely consider the great contextual variation caused by the mobility of the services and the demands this poses on usability; which, in turn, affects productivity. To build a measurement tool that better meets the requirements of mobile business services, we completed case studies on two mobile business services, one used in passenger transport and the other in construction sites. Based on the understanding gained from the case studies, we propose a list of dimensions and items addressing both usability and productivity aspects that work as the basis for a multidisciplinary measurement tool.
On Genocchi Numbers and Polynomials
Authors: Rim Seog-Hoon , Park Kyoung Ho , Moon Eun Jung
Published: September 2008

The main purpose of this paper is to study the distribution of
Genocchi polynomials. Finally, we construct the Genocchi zeta function which
interpolates Genocchi polynomials at negative integers.
Novel Hardware Implementation of the Cipher Message Authentication Code
Authors: Michail H. E. , Selimis G. , Galanis M. , Schinianakis D. , Goutis C. E.
Published: September 2008

A new algorithm for producing message authenticating codes (MACs) was recently proposed by NIST. The MAC protects both a message′s integrity—by ensuring that a different MAC will be produced if the message has changed—as well as its authenticity because only someone who knows the secret key could have generated a valid MAC. The proposed security scheme incorporates an FIPS approved and secure block cipher algorithm and was standardized by NIST in May, 2005. In this paper is presented the first efficient hardware implementation of the CMAC standard.
Fiber Optic Chemical Nanosensors Based on Engineered Single‐Walled Carbon Nanotubes: A Review
Authors: Consales M. , Cutolo A. , Penza M. , Aversa P. , Giordano M. , Cusano A.
Published: September 2008

In this contribution, a review of the development of high‐performance optochemical nanosensors based on the integration of carbon nanotubes with the optical fiber technology is presented. The paper first provide an overview of the amazing features of carbon nanotubes and their exploitation as highly adsorbent nanoscale materials for gas sensing applications. Successively, the attention is focused on the operating principle, fabrication, and characterization of fiber optic chemosensors in the Fabry‐Perot type reflectometric configuration, realized by means of the deposition of a thin layer of single‐walled carbon nanotubes (SWCNTs) upon the distal end of standard silica optical fibers. This is followed by an extensive review of the excellent sensing capabilities of the realized SWCNTs‐based chemical nanosensors against volatile organic compounds and other pollutants in different environments (air and water) and operating conditions (room temperature and cryogenic temperatures). The experimental results reported here reveal that ppm and sub‐ppm chemical detection limits, low response times, as well as fast and complete recovery of the sensor responses have been obtained in most of the investigated cases. This evidences the great potentialities of the proposed photonic nanosensors based on SWCNTs to be successfully employed for practical environmental monitoring applications both in liquid and vapor phase as well as for space. Furthermore, the use of novel SWCNTs‐based composites as sensitive fiber coatings is proposed to enhance the sensing performance and to improve the adhesion of carbon nanotubes to the fiber surface. Finally, new advanced sensing configurations based on the use of hollow‐core optical fibers coated and partially filled by carbon nanotubes are also presented.
5-Nitro-2-(3-Phenylpropylamino)benzoic Acid Is a GPR35 Agonist
Authors: Taniguchi Yasuhito , Tonai-Kachi Hiroko , Shinjo Katsuhiro
Published: September 2008

GPR35 is a Gi/o- and G16-coupled receptor abundantly expressed in gastrointestinal tissues and immune cells. Kynurenic acid (a tryptophan metabolite and ionotropic glutamate receptor antagonist) and zaprinast (a phosphodies- terase inhibitor) are GPR35 agonists. Here, we show that the chloride channel blocker 5-nitro-2-(3-phenylpropylamino) benzoic acid (NPPB) is also a GPR35 agonist. NPPB activates the GPR35-Gi/o and GPR35-G16 pathways in human embryonic kidney 293 (HEK293) cells and induces intracellular calcium mobilization in a concentration-dependent manner in HEK293 cells coexpressing human, rat or mouse GPR35 and the chimeric G protein Gqi5. These results suggest a novel pharmacological activity of NPPB and will provide useful information to search for more potent and selective GPR35 agonists.
Zur Darstellung der Vasa vasorum in der Tunica media der Arterienwand
Authors: Hundeiker M.
Published: September 2008

A strongly positive alkaline phosphatase reaction in endothelial cells of capillaries and some precapil laries and a considerable activity of α-naphthylacetate esterase in endothelial cells of postcapillary vessels allow a complete demonstration of vasa vasorum in arteries of the muscular type.This method gives results also in such parts of arteries or pieces of their wall which do not allow a demonstration of their vasa vasorum by means of injection methods. In the internal spermatic artery of the bull a dense rope-ladder shaped capillary network is demonstrable within the outer parts of the tunica media with the alkaline phosphatase and the α-naphthylacetate esterase reactions. The two methods also may be combined. Most of the vasa vasorum arise directly from the lumen of the artery. They set through the whole of the arterial wall and spread over the vessel with retrograde branches. A uniformely thick inner portion of the arterial wall has no capillaries.
Ein Beitrag zur Behandlung von Gefässverschlüssen der Netzhaut durch Fibrinolyse
Authors: Sautter H. , Rossmann H.
Published: September 2008

Fibrinolysis, the breaking up of the fibrin structure of thrombi into low molecular proteins, is a new principle in the treatment of occlusion of the retinal vessels. It has been tried in occlusion of both arterial and venous trunks and branches of the central retinal area. Good results can be obtained with this technique in selected patients. Attention must be paid, however, to the contraindications to the use of streptokinase for fibrinolysis, as these may prove fatal under certain circumstances. The subjective side effects resulting from the use of an extract of cultured β-hemolytic streptococci must be observed and treated.
The Vasa Vasorum Patterns in the Fetal Aorta of Sheep
Authors: Neumann F. , Rattner D. , Klopfer U. , Nobel T.A.
Published: September 2008

In 37 aortae of sheep fetuses of various ages, the medial vasa vasorum were investigated. The aortic segments which had more than 29 medial lamellar units displayed medial vasa vasorum. This occurred in the second month of gestation for the ascending and descending segments, and in the fifth month for abdominal aorta.
Saccular Aneurysm of the Venous Limb of an Arteriovenous Fistula Complicating its Use in Chronic Hemodialysis
Authors: Hashmonai M. , Schramek A. , Szylman P. , Auslaender L.
Published: September 2008

A case of a saccular aneurysm of the venous limb of an internal A-V fistula of the forearm is described. It developed a month after its creation and following the fourth dialysis. The mechanism of formation of the rare aneurysms of the venous limb central to arteriovenous fistulas is presumed to be increased blood pressure and flow of long duration. In this case, the cause is considered to be trauma by the needle during hemodialysis.
Strontium and Barium as Substitutes for Calcium on Electrical and Mechanical Activity in Rat Portal Vein
Authors: Uvelius Bengt , Sigurdsson Stefan B. , Johansson Börje
Published: September 2008

Sr (above 0.5 mm) and Ba (above 0.25 mm) can maintain spontaneous electrical activity of portal vein in the absence of Ca. This is true also in Na-free solution. An approximately normal pattern of activity with well-defined periods of quiescence is obtained with Sr at lower concentrations than with Ca. Ba causes continuous tetanic spike discharge. Excitation-contraction coupling appears less effective with Sr and Ba than with Ca. These differences can explain the different concentration-effect curves obtained for the three ions with regard to integrated isometric force. The contracture responses of depolarized portal vein induced by Ca, Sr or Ba decreased by 27, 44 and 63 %, respectively, after 30 min in Ca-free solution with 1 mm EGTA. No further decrease occurred after 2 h. The mechanical responses to Sr and Ba appear to be combined effects of liberation of tissue Ca and direct action on the contractile system.
Localization and Measurement of Microvascular and Microcirculatory Responses to Venous Pressure Elevation in the Rat
Authors: Baez Silvio , Laidlaw Zona , Orkin Louis R.
Published: September 2008

The effect of increase in regional draining venous pressure on the response of mesoappendix microvasculature and microcirculation was studied by direct microscopic methods in vivo. In 9 out of 21 experiments in pentobarbital anesthetized rats, elevation of ileo-colic vein pressure (13.0 ± 1.3 mm Hg; mean and SE) above resting levels (9.9 ± 2.2 mm Hg) resulted in persistent lumen expansion of small venular microvessels (18-68 µm, i.d.) and evoked a vasoconstrictor response of consecutive segments of pre-capillary vessels and the sphincter. The vasoconstricor response was stimulus-dependent and reversible. The lumen reductions in percent for 9 arterioles (21.0 ± 4.37 µm, i.d.) 9 metarterioles (9.3 ± 1.57 µm, i.d.), and 5 precapillary sphincters (5.7 ± 1.23 µm, i.d.) were: 17.9 ± 6.60, 43.6 ± 4.20, and 96.0 ± 3.81, respectively. In none of the experiments did the response propagate to larger arteriolar segments ( > 35–38 µm, i.d.) in the tissue under observation. These microscopic studies confirmed the presence of a venous-pre-capillary and sphincter constrictor response in splanchnic vasculature in the rat.
Adrenergic Mechanisms in the Rabbit Ear Artery
Authors: de la Lande Ivan S.
Published: September 2008

A number of factors which have been implicated in the response of the rabbit ear artery to adrenergic agents and stimuli are reviewed. Aspects discussed include: (a) the method of propagation of vasoconstriction in the arterial smooth muscle; (b) the interrelationship between the intramural distribution of sympathetic nerves and muscle, and the influence of uptake and enzymic inactivation on the response to norepinephrine, and (c) the influence of presynaptic adrenergic and cholinergic receptors on the response to sympathetic nerve stimulation.
Enhanced Prostaglandin Synthesis Contributes to the Venoconstrictor Activity of Ergotamine
Authors: Müller-Schweinitzer Else , Brundell Jan
Published: September 2008

Spiral strips from dog saphenous veins were contracted by 2.5 × 10–9 M ergotamine, a concentration giving about 50% of maximal response. Phentolamine (3.6 × 10–6 m) reduced these effects by 60% and indomethacin (2.8 × 10–7 m) by 30%. Indomethacin was more effective in reducing ergotamine-induced increase of prostaglandin E-like activity in the bathing fluid than those induced by noradrenaline or potassium chloride. Arachidonic acid was more effective in increasing tension in ergotamine-stimulated than in noradrenaline- or potassium-stimulated veins. These findings suggest that the long-lasting venoconstrictor activity of ergotamine is mediated mainly by α-adrenoceptors but that enhanced formation of prostaglandin E-like substance(s) may also contribute.
Vasodilator Effect of Thrombins Prepared from Normal or Deficient Human or Canine Plasmas
Authors: Iatridis Panayotis G. , Yonce Lloyd R. , Joyner William L.
Published: September 2008

Thrombins prepared from plasmas deficient in various clotting factors are capable of inducing vasodilator response to the hindlimb of the dog and this response proved to be similar to that produced by thrombins prepared from normal plasmas. Thus the vascular effect of thrombin is not mediated by any other clotting factor which might be present in small amounts in the thrombin preparations. Thrombin prepared from canine normal plasma exerted a more potent vasodilator response, indicating a species specificity for the vascular response to thrombin. Since the vasodilating effect of thrombin is not mediated by (i) a nervous mechanism, (ii) any known vasodilating substance or (iii) any other clotting factor, it is concluded that the thrombin moiety possesses vasodilating properties.
Influence of H+ on K+ on Adenosine-Induced Dilatation at Pial Arteries of Cats
Authors: Wahl Michael , Kuschinsky Wolfgang
Published: September 2008

The influence of changes in the perivascular K+ and H+ concentrations upon adenosine-induced dilatations of pial arteries was investigated by localized perivascular application using micropuncture technique. Adenosine (10–9–10–3 m) was dissolved in mock spinal fluids with varying bicarbonate and potassium concentrations (5 and 22 mM HCO3–, and 6 and 10 mM K+). Concentration response curves revealed that adenosine induced the same change in pial arterial diameter when dissolved either in an inert (11 mM HCO3–) or in a constrictory (22 mM HCO3–) mock spinal fluid. However, adenosine, when dissolved in a more acidic or higher postassium-containing solution (5 mM HCO3–, or 6 or 10 mM K+) produced a diminished dilatatory effect. It is concluded that, for a quantification of the individual contributions of several metabolic factors in the regulation of vascular resistance, it is necessary to consider their interactions. 1 A preliminary report of a part of this investigation was presented at the Symposium on ‘The Role of Ions in the Transmission of Signals from Tissue and Bloodto the Vascular Smooth Muscle Cells’, Tubingen, February 12–14, 1976 [publishedin Betz, 1976]. 2 Supported by the ‘Deutsche Forschungsgemeinschaft’.
Laser-Induced Thrombus Formation and Vascular Reactivity in the Microcirculation of the Spontaneously Hypertensive Rat
Authors: Görög Peter , Kovács Iren B.
Published: September 2008

Thrombi formation resulting from laser-induced injury to mesenteric circulation has been studied in spontaneously hypertensive (SH) and normotensive rats. The thrombotic reaction was enhanced in both venules and arterioles of the SH rats. In the arterioles of the hypertensive rats, the vasoconstriction which develops downstream from the thrombus is greatly intensified and the time to form micro-vascular haemostatic plugs significantly decreased in the arterioles of these animals. These phenomena have been explained on the basis of an increased reactivity of the vascular smooth muscle of the SH rats to vasoconstrictor substances liberated from platelets at the site of injury.
Presence of Hormonally-Sensitive Adenylate Cyclase Receptors in Capillary-Enriched Fractions from Rat Cerebral Cortex
Authors: Baca George M. , Palmer Gene C.
Published: September 2008

The 10 000 g particulate fraction from capillary-enriched fractions isolated from rat cerebral cortex was shown to possess an adenylate cyclase highly sensitive to activation by sodium fluoride, norepinephrine, epinephrine, isoproterenol and dopamine. To a lesser extent histamine and three dopamine agonists, namely M-7 (5, 6-dihydroxy-2-dimethylamino tetralin), ET-495 (methane sulfonate of pyribedil), and S-584 (metabolite of pyribedil) stimulated the enzyme preparation. The action of norepinephrine was blocked by propranolol while phenotolamine and haloperidol were relatively ineffective except at highest concentrations. Phentolamine and propranolol at only highest concentrations (10–4 m) antagonized the action of dopamine. Haloperidol was seen to be a potent inhibitor of either dopamine- or dopamine agonist-sensitive adenylate cyclase. No effects on the enzyme were observed with methoxamine, octopamine or serotonin. These preliminary data suggest the presence of a mixed population of receptors for adenylate cyclase in rat brain capillaries.
The Role of Sodium and Potassium Ions in the Contractile Response and Development of Tachyphylaxis to Angiotensin II on Vascular Smooth Muscle
Authors: Moore Alan F. , Khairallah Philip A.
Published: September 2008

The role of sodium and potassium ions, and the possible involvement of the membrane sodium pump has been studied in the development of a contractile response to, and the development of tachyphylaxis to, angiotensin II. It is suggested that a membrane depolarization may have a role in the mechanism of the contractile response to angiotensin II, as responses of the rabbit aorta to angiotensin II were selectively inhibited in K-free medium. Acute or chronic increases in medium sodium, however, did not influence the response of the rabbit aorta to angiotensin II. On the rat aorta increased medium sodium concentrations potentiated the response to angiotensin II and inhibited the development of tachyphylaxis. Membrane depolarization or hyperpolarization does not appear to be part of the mechanism of development of tachyphylaxis to angiotensin II on the rat aorta, as response to both NE and angiotensin II were inhibited equally by exposure of the rat aorta to K-free medium, i.e., nonspecific desensitization occurred, as opposed to the specific desensitization which defines tachyphylaxis.
Action Potential Generation in Reaggregates of Rat Aortic Smooth Muscle Cells in Primary Culture
Authors: Harder David R. , Sperelakis Nick
Published: September 2008

Cultured vascular smooth muscle cells were prepared from adult rat aortas. The cells were dispersed by collagenase/elastase, and allowed to reaggregate into small spheres (50–200 µm in diameter) by plating on to cellophane. These primary cultures were incubated for 5–14 days, and then impaled with microelectrodes. The mean resting potential was –55 mV, and the mean input resistance was 9.0 MΩ. The cells were quiescent, electrically and mechanically, and electrical stimulation usually did not elicit responses. However, addition of Ba++ (1 mM) or tetraethylammonium ion (TEA; 5–15 mM) induced excitability (with accompanying contractions), either as spontaneous action potentials or by allowing responses to electrical stimulation. The cells became partially depolarized (e.g., to –36 mV) by these agents, and the input resistance increased. The frequency of spontaneous firing of the Ba++-induced spikes was affected by polarizing current pulses, as expected for pacemaker behavior. Elevation of Ca++ in the bathing solution increased the amplitude (overshoot) of the action potentials, and the spikes were blocked by verapamil (10–5M). Electron microscopy showed that the reaggregates consisted of a tight packing of elongated small-diameter cells, some of which exhibited thick and thin myofilaments and ‘dense bodies’; many cells possessed surface caveolae. The results of this study demonstrate that reaggregates of arterial smooth muscle in primary culture can maintain functional and morphological characteristics of intact arterial smooth muscle, and therefore provide a useful preparation for the study of vascular smooth muscle function and control.
Constriction of Ear Arteries from Normotensive and Renal Hypertensive Rabbits against Different Transmural Pressures
Authors: Speden R.N. , Ryan Ann T.
Published: September 2008

Isolated segments of rabbit ear arteries were made to constrict against normotensive and hypertensive transmural pressures by perfusion with submaximal concentrations of norepinephrine (NE). Changes in load (force/unit length of artery) and stress (force/wall cross-sectional area) during constriction against a constant pressure have been evaluated. Weak concentrations of NE constricted the arteries equally well against transmural pressures of 80 and 120 mm Hg and, in doing so, utilized much of the contractile capacity of the muscle. A stretch-mediated, co-operative interaction between muscle cells has been put forward to explain these observations. Ear arteries from renal hypertensive rabbits differed from those of normotensive rabbits in having a higher NE threshold concentration and in constricting better against 140 mm Hg. They did so because of the mechanical advantage provided by a smaller internal radius and a thicker wall which reduced the load and stress placed on the muscle by the pressure. No muscle hyperplasia or hypertrophy was detected.
Adrenergic and Peptidergic (Substance P and Vasoactive Intestinal Polypeptide) Innervation of the Rat Portal Vein
Authors: Barja Francisco , Mathison Ron
Published: September 2008

The adrenergic innervation of the rat portal vein is subdivided into two plexuses: the adventitial and the medial. Nerve fibres containing immunoreactive substance P (SP) are present in the adventitial and medial plexuses, and extend into the longitudinal and circular muscle layers. Vasoactive intestinal polypeptide (VIP) immunofluorescence is restricted to the adventitial plexus. The catecholamine modulation of the intrinsic rhythmical contractions of the portal vein may be complemented by SP released from intramural nerves and VIP released from the adventitial nerves.
Spontaneous Electrical Activity in Pressurized Small Mesenteric Arteries
Authors: Zelcer Elane , Sperelakis Nick
Published: September 2008

Spontaneous electrical activity was recorded intracellularly in vitro from smooth muscle cells of guinea pig small pressurized mesenteric arteries. Spontaneous action potentials were recorded at 37 °C at frequencies of 30–55/min. Each action potential consisted of a prepotential (pacemaker potential) followed by a spike of variable amplitude (10–35 mV). This activity was not blocked by tetrodotoxin (TTX) or guanethidine, indicating it was myogenic in origin. Sympathetic nerve stimulation (single 0.5-ms field stimuli) could evoke action potentials in between the spontaneous action potentials and could drive the activity; this effect was blocked by TTX. Addition of the vasodilator adenosine (10–6 to 10–4M) reversibly decreased action potential amplitude and frequency. Lowering the temperature to 35 °C for 1–3 min during a single impalement decreased spontaneous action potential frequency. Spontaneous activity was abolished after longer periods at 35 °C. The spontaneous activity recorded in vitro at 37 °C and 5 or 40 mm Hg inflation pressure was similar to that previously reported from guinea pig and rat mesenteric arteries in vivo. Such activity might be important in the normal physiological control of arterial tone.
Depressed Adrenergic Nerve Function in Tibial Arteries of Two-Kidney One Clip Goldblatt Hypertensive Dogs
Authors: Zimmerman Ben G. , Friedman Patricia L. , Wong Pancras C.
Published: September 2008

Tibial arteries removed from normotensive dogs and from two-kidney one clip Goldblatt hypertensive dogs, 6–34 days after renal artery constriction, were studied in vitro. Contractions were elicited by transmural stimulation and norepinephrine added to the organ bath. Arteries from the hypertensive dogs exhibited depressed responsiveness to adrenergic nerve stimulation, but not to the lower concentrations of norepinephrine. However, the maximal response to norepinephrine was decreased as has been previously observed in hypertensives’ arteries. The results indicate that pre- and postsynaptic factors are involved in the depressed adrenergic responses in the hypertensives’ tibial arteries.