bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Effect of Adrenalectomy on Ghrelin Secretion and Orexigenic Action
Authors: Proulx K. , Vahl T. P. , Drazen D. L. , Woods S. C. , Seeley R. J. 
Published: June 2005

AbstractGhrelin is an orexigenic peptide made both in the periphery and in the central nervous system. Relatively little is known about the factors that regulate ghrelin secretion. Because both ghrelin and glucocorticoids are increased during fasting, we hypothesised that ghrelin secretion from the stomach is stimulated by glucocorticoids. Plasma ghrelin concentrations were determined by radioimmunoassay in fed and fasted adrenalectomised (ADX) and sham‐operated rats. Fasting plasma ghrelin concentrations were significantly increased in ADX relative to sham rats and were normalised by glucocorticoid replacement. Several lines of evidence suggest that the orexigenic action of ghrelin is mediated through neuropeptide Y (NPY)/agouti‐related peptide (AgRP) neurones. Because ADX reduces the orexigenic actions of NPY and AgRP, we hypothesised that ADX would also reduce the orexigenic action of ghrelin. Food intake was assessed in ADX and sham rats following an intra‐third‐ventricular injection of either saline or ghrelin (1, 5 or 10 µg in 2 µl). ADX rats were equally sensitive to the orexigenic action of ghrelin compared to sham rats. Given that ghrelin has been shown to stimulate glucocorticoid secretion, the current data imply the existence of a regulatory feedback loop whereby glucocorticoids inhibit further ghrelin secretion. The results also suggest that, unlike the orexigenic effects of NPY and AgRP, the ability of ghrelin to stimulate food intake is maintained in ADX rats.
Expression of GABAB Receptors in Magnocellular Neurosecretory Cells of Male, Virgin Female and Lactating Rats
Authors: Richards D. S. , Villalba R. M. , Alvarez F. J. , Stern J. E. 
Published: June 2005

AbstractGABA is one of the key neurotransmitters that regulate the firing activity of neurones in the supraoptic (SON) and paraventricular (PVN) nuclei. In the present study, we used immunohistochemical techniques to study the distribution and subcellular localisation of metabotropic GABAB receptors in magnocellular neurones in the SON and PVN. Robust GABAB receptor immunoreactivity (GABABR; both subunit 1 and subunit 2 of the heterodimer), was observed in the SON and PVN. At the light microcope level, GABABR immonoreactivity displayed a clustered pattern localised both intracytoplasmically and at the plasma membrane. Densitometry analysis indicated that GABABR immunoreactivity was significantly more intense in vasopressin cells than in oxytocin cells, both in male, virgin female and lactating rats, and was denser in males than in virgin females. Light and electron microscope studies indicated that cytoplasmic GABABR was localised in various organelles, including the Golgi, early endosomes and lysosomes, suggesting the cycling of the receptor within the endocytic and trafficking pathways. Some smaller clusters at the level of the cell plasma membrane were apposed to glutamic acid decarboxylase 67 immunoreactive boutons, and appeared to be colocalised with gephyrin, a constituent protein of the postsynaptic density at inhibitory synapses. The presence of GABABR immunoreactivity at synaptic and extrasynaptic sites was supported by electron microscopy. These results provide anatomical evidence for the expression of postsynaptic GABAB receptors in magnocellular neurosecretory cells.
Measuring Seasonal Time within the Circadian System: Regulation of the Suprachiasmatic Nuclei by Photoperiod
Authors: Johnston J. D. 
Published: June 2005

AbstractDay‐length (photoperiod) is the primary environmental signal used to synchronise endogenous rhythms of physiology and behaviour. In mammals, the suprachiasmatic nuclei (SCN) of the hypothalamus house the master circadian clock. The SCN incorporate photoperiodic information and therefore measure both daily and seasonal time. Over the past decade, there have been significant advances in the understanding of the molecular basis of circadian clocks. It is now becoming apparent that the core molecular clock mechanism is itself regulated by photoperiod, although there is currently debate as to how this occurs. One recent model proposes that distinct groups of core ‘clock genes’ are associated with either morning or evening phases of the daily light/dark cycle. However, the validity of associating particular genes to morning and evening has been questioned. This article reviews the evidence for photoperiodic regulation of circadian clock function and then discusses alternative models that may explain the available data.
Neuroendocrine Regulation of Prolactin Secretion During Late Pregnancy: Easing the Transition into Lactation
Authors: Andrews Z. B. 
Published: June 2005

AbstractProlactin is an anterior pituitary hormone critical for maintaining pregnancy and lactation. Under normal conditions, prolactin secretion is tightly regulated by inhibitory dopaminergic neuronal systems within the mediobasal hypothalamus in a process known as short‐loop negative feedback. This review focuses on neuroendocrine adaptations to prolactin negative feedback during late pregnancy. It is suggested that, in terms of prolactin regulation, late pregnancy is a transition period into lactation because many of the neuroendocrine adaptations promoting hyperprolactinemia in lactation develop during late pregnancy. As a consequence, the maternal brain is geared to provide unrestrained prolactin release critical for milk production, maternal care and thus survival of the offspring before parturition. The mechanisms responsible for these changes are discussed.
Effects of moxifloxacin on QT interval in conscious dogs
Authors: MITTELSTADT S. W. , HART S. M. 
Published: June 2005

Moxifloxacin has been shown to induce QT prolongation in both clinical and preclinical models. However, the ability to observe this effect at clinically relevant concentration in normal conscious dogs has not been reported. The purpose of this study was to investigate the effects of moxifloxacin on the QT interval in conscious, healthy dogs.Four male mongrel dogs were chronically instrumented for the measurement of arterial blood pressure, left ventricular blood pressure, cardiac output, electrocardiograms (ECGs), and body temperature. Animals were administered a 1‐h i.v. infusion of moxifloxacin once per day via a catheter in the cephalic vein. Each dog received all doses (0, 1, 10, 25 and 50 mg/kg) in an escalating fashion.Moxifloxacin caused a statistically significant increase in arterial blood pressure at 50 mg/kg. A dose–response effect on QT and QTc prolongation was observed. A statistically significant prolongation in the QT interval was observed at 10, 25 and 50 mg/kg and a prolongation of QTc was observed at 25 and 50 mg/kg. These effects occurred at clinically relevant plasma concentrations. This study demonstrate that a study design with four dogs was sensitive enough to measure moxifloxacin‐induced QT prolongation at clinically relevant plasma concentrations.
Peptide‐Based Instruction of Suppressor Commitment in Naïve T Cells and Dynamics of Immunosuppression in vivo
Authors: Von Boehmer H. 
Published: June 2005

AbstractRecent years have witnessed the revival of suppressor T cells that control immunity by interfering with the generation of effector T‐cell function in vivo. The discovery that CD4 T cells with the CD25 surface marker were enriched in suppressor activity enabled further phenotypic and functional analysis of the so‐called natural suppressor cells. In vitro characterization showed that these cells were anergic, i.e. did not respond to antigenic stimulation with proliferation and, instead they suppressed other cells through direct cell contact resulting in inhibition of interleukin‐2 gene transcription. We have analysed the generation and function of suppressor T cells in T‐cell receptor (TCR) transgenic mice. The results showed that such cells can be generated intrathymically when agonist TCR ligands are expressed on thymic epithelial cells. Thus generated cells constitute a lineage of cells committed to suppression only with the ability to survive for prolonged periods of time in the absence of the inducing ligand. Because of appropriate homing receptors such cells can accumulate and proliferate in antigen draining lymphnodes after antigenic stimulation and suppress proliferation and cytokine secretion of CD4 and CD8 T cells as well as CD8 T‐cell‐mediated cytotoxicity. We also attempted to generate such cells from naïve T cells in secondary lymphoid tissue under conditions where expansion of already preformed suppressor T cells could be excluded. The results showed that subimmunogenic peptide delivery by osmotic minipumps or by peptide containing DEC 205 antibodies yielded CD25+ suppressor cells that were phenotypically and functionally indistinguishable from intrathymically generated suppressor cells. The experiments with DEC205 antibodies revealed (i) dose‐dependent proliferation of naïve T cells and (ii) conversion into suppressor T cells of only those T cells that underwent a limited number of cell divisions. These results are compatible with other studies that were, however, less rigorous in excluding expansion of existing cells as opposed to de novo generation of suppressor cells from naïve T cells. The fact that natural suppressor cells have an essential role in preventing autoimmunity and that they can be specifically induced by TCR agonist ligands opens new perspectives in preventing autoimmunity, transplant rejection and allergy.
Stromal Cells Attract B‐Cell Progenitors to Promote B‐Cell–B‐Cell Contact and Maturation
Authors: Milne C. D. , Zhang Y. , Paige C. J. 
Published: June 2005

AbstractThe in vitro differentiation of B‐lineage progenitors into Ig‐secreting mature B cells has classically required a co‐culture system containing lipopolysaccharide (LPS) and stromal cells. We have previously showed that B‐lineage progenitors cultured in round‐bottomed wells can mature and secrete immunoglobulin M (IgM) on par with cultures containing stromal cells. This clearly demonstrates that any factors essential for progenitor cell maturation can be found in cultures containing media, serum, LPS and B‐cell progenitors. However, stromal cells are important for the maturation observed when cells are cultured in flat‐bottomed wells. We hypothesized that stromal cells may attract B‐cell progenitors and promote contacts between responsive cells, a phenomenon that is mimicked by the cultures in round‐bottomed wells. In this study, we explore how stromal cells accomplish these functions. We show that stromal cells attract B‐cell progenitors in a pertussis toxin‐sensitive manner. The stromal cell line S17 produces the chemokine CXCL12, which is able to induce the chemotaxis of B‐lineage progenitors. Chemotaxis can be blocked by a small peptide inhibitor (T134) of CXCR4, the CXCL12 receptor. Further, disrupting chemotaxis can reduce the supportive role played by S17 when B‐lineage progenitors are cultured in flat‐bottomed wells.
Immunoadsorbent Assay Application for Studies of Protein Mixtures and Usage of Paper Carriers
Authors: Nezlin R. 
Published: June 2005

AbstractProteins immobilized on insoluble carriers or immunoadsorbents are now widely used in many areas of biological research. They are especially efficient in studies of complex protein mixtures because immunoadsorbents are very useful for isolation of individual components for further investigation. Antibodies immobilized on paper retain their specific activity and can be applied as very sensitive measurement tool.
From Clones of Cells to Cloned Genes and the Proteinpaedia
Authors: Kettman J. R. 
Published: June 2005

AbstractThis brief description follows the association of the author with Ivan Lefkovits from 1971 until this volume. Sketches of our mutual interests are included. Time periods in California, Basel and Texas are described. Decisions about preparing new tools for clonal analysis are elucidated, and experimental approaches leading to the x‐omic revolution are described.
Origin and Development of a Scientific Collaboration and a Long‐Lasting Friendship
Authors: Luzzati A. L. 
Published: June 2005

AbstractThe aim of this contribution is twofold: to honour Ivan Lefkovits with a short recollection of our scientific collaboration in the years 1972–1985 and a summary of our joint contribution to studies of the mechanisms and functions of the immune system and to acknowledge our long‐lasting friendship. Ivan's limiting dilution microculture method was adapted to rabbit peripheral blood lymphocytes (PBL). The antibody produced in the responding cultures was shown to be electrophoretically homogeneous and, in rabbits heterozygous at the b locus, to express either one or the other allele. Thus, the antibody released in single microcultures was indeed the product of single B‐cell clones and allelic exclusion, once achieved, was maintained throughout clonal proliferation. In the response to streptococcal polysaccharides, analysis of the clonotypes triggered in vitro provided information on mechanisms of clonal dominance. A two‐stage culture system was established, where rabbit PBL were precultured at low cell density with antigen before being partitioned in limiting dilution cultures. This method provided a new tool for studies of various cellular aspects of the immune response. Moreover, it allowed the application of the limiting dilution analysis to PBL from unprimed animals. Later, the method was extended with success to human PBL, leading to studies of regulatory aspects of immunity in this species.
Association between sharing of toothbrushes, eating and drinking habits and the presence of Actinobacillus actinomycetemcomitans in Moroccan adolescents
Authors: Haubek D. , Ismaili Z. , Poulsen S. , Ennibi O.‐K. , Benzarti N. , Baelum V. 
Published: June 2005

Background/aims:  Actinobacillus actinomycetemcomitans is frequently detected in dental plaque collected from Moroccan adolescents, and has been shown to be associated with clinical attachment loss in this population. The aim of this study was to assess whether behaviors such as the sharing of toothbrushes, and eating and drinking habits were associated with the presence of A. actinomycetemcomitans in Moroccan adolescents.Materials and methods:  A total of 121 adolescents were clinically examined. Interviews regarding sharing of toothbrushes, eating and drinking habits were performed, and plaque samples were collected and analyzed for A. actinomycetemcomitans with different leukotoxin promoter types by polymerase chain reaction. Based on eating and drinking habits, the study population was divided in a low risk behavior group (LRB) and a high risk behavior group (HRB).Results:  No association was found between the sharing of toothbrushes and the presence of A. actinomycetemcomitans. The odds ratios between the HRB and LRB group for being positive for the JP2 type, for non‐JP2 types, and for any type of A. actinomycetemcomitans were 4.74 (95% CI 0.55; 40.71), 2.49 (95% CI 1.03; 5.97), and 2.97 (95% CI 1.28; 6.91), respectively. The difference in the mean number of teeth with a clinical attachment loss of ≥ 3 mm between the HRB and the LRB group was 0.91(95% CI 0.09; 1.72).Conclusion:  Sharing of toothbrushes does not seem to be associated with the presence of A. actinomycetemcomitans in young Moroccans. Eating and drinking habits conducive to exchange of saliva are positively associated with presence of A. actinomycetemcomitans, and with a higher level of clinical attachment loss.
In vitro activity of a monoclonal killer anti‐idiotypic antibody and a synthetic killer peptide against oral isolates of Candida spp. differently susceptible to conventional antifungals
Authors: Manfredi M. , McCullough M. J. , Conti S. , Polonelli L. , Vescovi P. , Al‐karaawi Z. M. , Porter S. R. 
Published: June 2005

Background/aims:  A monoclonal killer anti‐idiotypic antibody (mAbK10) and a synthetic killer peptide, acting as internal images of a microbicidal, wide‐spectrum yeast killer toxin (KT) have been recently shown to express candidacidal in vitro and an in vivo therapeutic activity against experimental mucosal and systemic candidosis models caused by a reference strain of Candida albicans (10S).Material and methods:  The in vitro candidacidal activity of mAbK10 and synthetic killer peptide was compared using a colony forming unit assay against a large number of isolates of different Candida spp., obtained from oral saliva of adult diabetic (type 1 and 2) and nondiabetic subjects from Parma (Italy) and London (UK).Results:  Both the KT‐mimics exerted a strong dose‐dependent candidacidal activity, probably mediated by the interaction with β‐glucan KT receptors on target yeast cells, against all the tested strains, regardless of their species and pattern of resistance to conventional antifungal agents.Conclusions:  These observations open new perspectives in the design and production of candidacidal compounds whose mechanism reflects that exerted in nature by killer yeasts.
Antimicrobial susceptibility variation of 50 anaerobic periopathogens in aggressive periodontitis: an interindividual variability study
Authors: Lakhssassi N. , Elhajoui N. , Lodter J.‐P. , Pineill J.‐L. , Sixou M. 
Published: June 2005

Background/aims:  The frequent use of antibiotics in developed countries has led to the emergence of widespread bacterial resistance. In this study, the interindividual variability of the antibiotic susceptibility of 50 putative microorganisms in aggressive periodontitis patients has been evaluated by means of VC (variation coefficient).Material and methods:  A total of 60 microbial samples were collected from 20 adult patients diagnosed with aggressive periodontitis (2–4 samples by patient). Bacterial strains of Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia, Fusobacterium nucleatum, and Peptostreptococcus micros were isolated according to Slots' rapid identification method. The susceptibilities to 10 antibiotics were studied: penicillin G (PEN), ampicillin (AMP), amoxicillin (AMX), amoxicillin/clavulanate (AMC), tetracycline (TET), doxycycline (DOX), ciprofloxacin (CIP), erythromycin (ERY), spiramycin (SPI) and clindamycin (CLIN), using the Disk Diffusion Susceptibility test (DDS test: Kirby‐Bauer's modified method for anaerobic bacteria). The broth microdilution Minimum Inhibitory Concentration test was carried out as a control test.Results:  Among the 50 identified bacteria, 15 were P. gingivalis, 12 P. intermedia, 8 T. forsythia, 9 F. nucleatum, and 6 P. micros. The results of the DDS test show that penicillins (especially AMC, AMP, and AMX), cyclines (especially DOX) and CLIN are highly effective against the 50 anaerobic studied bacteria. CIP and ERY have the lowest efficacy against those bacteria. CIP shows a very variable activity according to anaerobic bacteria species, being particularly inactive against P. gingivalis and very efficient against T. forsythia and P. micros. SPI is also highly efficient but not against P. micros.Conclusions:  The interindividual susceptibility of principal periodontal pathogens to antibiotics is not homogeneous and seems to vary according to bacterial species and antimicrobial molecules. This variability seems to be greater with older molecules (PEN, TET, ERY) than with more recent ones, which indicates more stable results (AMC, AMX, AMP, and DOX). P. intermedia appeared to be the bacteria most resistant to penicillins and showed the highest coefficient variation. Together with scaling and root planing, the combination of two antibiotics would therefore seem to be recommended in the treatment of aggressive periodontitis, particularly in the presence of P. intermedia.
No evidence of in vitro and in vivo porcine endogenous retrovirus infection after plasmapheresis through the AMC‐bioartificial liver
Authors: Di Nicuolo Giuseppe , van de Kerkhove Maarten‐Paul , Hoekstra Ruurdtje , Beld Marcel G. H. M. , Amoroso Pietro , Battisti Sonia , Starace Maria , Florio Ernesto di , Scuderi Vincenzo , Scala Simona , Bracco Adele , Mancini Antonio , Chamuleau Robert A. F. M. , Calise Fulvio 
Published: June 2005

Abstract:  Background:  Currently a number of bioartificial livers (BAL) based on porcine liver cells have been developed as a treatment to bridge acute liver failure patients to orthotopic liver transplantation or liver regeneration. These xenotransplantation related treatments hold the risk of infection of treated patients by porcine endogenous retrovirus (PERV) released from the porcine cells, as in vitro infection experiments and transplantations in immunocompromised mice have shown that PERV is able to infect human cells. The Academic Medical Center (AMC)‐BAL, unlike other BALs, is characterized by direct contact between porcine liver cells and human plasma, and might therefore be permissive for PERV transfer.Methods:  Prior to a clinical phase I trial, human plasma perfused through the AMC‐BAL was investigated for PERV DNA and RNA. Moreover productive infectivity was analyzed by exposing the plasma to HEK‐293 cells that were subsequently tested for PERV DNA, PERV RNA and reverse transcriptase activity.Results:  Although PERV DNA was detected in the perfused plasma, no productive infectivity was detected. Consequently fourteen patients were treated with the AMC‐BAL and monitored for PERV transmission. Immediately after treatment the plasma of the patients was positive for PERV DNA, most probably due to porcine liver cell lysis. The PERV DNA was cleared within 2 weeks post‐treatment and no PERV RNA was detected. No productive infectivity in human embryonic kidney (HEK)‐293 cells exposed to plasma of treated patients was detectable.Conclusion:  To conclude, no release of infective PERV particles from the AMC‐BAL was observed. Therefore we consider the AMC‐BAL as safe, however careful surveillance of patients will be continued.
Characterization of the swine major histocompatibility complex alleles at eight loci in Westran pigs
Authors: Lee Jun‐Heon , Simond Denbigh , Hawthorne Wayne J. , Walters Stacey N. , Patel Anita T. , Smith Douglas M. , O'Connell Phillip J. , Moran Chris 
Published: June 2005

Abstract:  Background:  Pigs are an important large animal model for transplantation and a potential source of xenografts. Swine leukocyte antigen (SLA) molecules are strong mediators of alloreactive and xenoreactive immune responses. We have characterized the SLA alleles of a new pig line bred for transplantation research, the Westran (Westmead Hospital transplantation) pig, described in a companion paper.Methods:  Three sixth generation inbred Westran pigs and a Large White pig control were used to assess SLA alleles. We examined the SLA‐1, SLA‐3, SLA‐6, SLA‐2, DQA1, DQB1, DRA1 and DRB1 loci using reverse transcription‐polymerase chain reaction and sequencing‐based method.Results:  All of the Westran pigs had a single allele at each locus, except for the SLA‐1 locus. Typing of the SLA‐1 locus in additional animals indicated that this is most likely the result of a duplication of the SLA‐1 locus rather than heterozygosity. The lack of SLA heterozygosity is consistent with the previous finding of low microsatellite marker heterozygosity and is the result of both the recent deliberate inbreeding of these pigs and their derivation from a feral stock from Kangaroo Island, South Australia, established by the release of a single pair in 1803.Conclusions:  After comparing DNA and protein sequences of the Westran SLA alleles with published GenBank SLA sequences, the SLA class I alleles found in the Westran pigs were all novel, while the SLA‐DR and DQB1 alleles have been previously described in other pig breeds. Characterization of the SLA alleles in the Westran pigs has identified novel alleles and will be useful for designing protocols for modulation of immune responses to allografts and xenografts.