bluuebunny/crossref_metadata_2025 huggingface dataset:
Regulation of Galanin Receptor GalR1 mRNA Expression by Ovarian Steroids in Oestrogen Receptor Alpha‐Immunoreactive Neurones: Identification of Distinct Populations of Neurones in the Preoptic Area
Authors: Mitchell V. , Lecompte F. , Beauvillain J. C.
Published: February 2004

This study examined whether gonadal steroids are involved in regulating galanin receptor 1 (GalR1) mRNA expression in neurones that contain oestrogen receptor alpha (ERα), in three regions of the preoptic area (POA) known to be involved in the control of gonadotropin secretion. Double‐labelling immunohistochemistry using an antibody against the ERα and in situ hybridization experiments using a 35S‐labelled riboprobe specific for GalR1 mRNAs revealed that ERα is expressed in a large proportion of GalR1 mRNA‐expressing neurones of the POA in the ovariectomized (OVX) female rat. Oestradiol (E2) and oestradiol plus progesterone (E2 + P) treatments of OVX rats significantly decreased the proportion of GalR1 mRNA/ERα immunoreactive (ERα‐IR) neurones in the anteroventral periventricular nucleus (AVPV), medial preoptic nucleus (MPN) and medial preoptic area (MPO). The expression of GalR1 mRNA in ERα‐IR neurones varied according the hormonal status of the female animals. In the AVPV, during the oestrous cycle, the hybridization signal significantly increased at oestrus. E2 and E2 + P treatments of OVX rats did not induced significant variation of levels of GalR1 mRNAs in ERα‐IR neurones. In the MPN, E2 treatment of OVX rats resulted in significant increase in GalR1 mRNA expression in ERα‐IR neurones. Similarly, levels of the GalR1 hybridization signal increased during afternoon of proestrus and oestrus. In the MPO, treatment of OVX rats with E2 + P significantly decreased GalR1 mRNA expression in ERα‐IR neurones. The expression of GalR1 mRNA did not change during the oestrous cycle in this area. These findings suggest that the hypothalamic action of galanin on gonadotopin‐releasing hormone (GnRH) secretion may pass through the specific population of GalR1/ERα‐IR neurones of the MPN in mediating the oestrogen action on the GnRH system at the moment of the luteinizing hormone surge.
Corrosion behaviour of an indigenous Ag‐Sn‐Cu cast dental alloy in artificial saliva
Authors: Patro T. K. , Singh B. P. , Singh V.
Published: January 2004

The corrosion behaviour of an indigenous cast alloy of Ag‐Sn‐Cu, developed for crown and bridge prostheses, was studied in artificial saliva, with and without the addition of 0·1
m
lactic acid, using a potentiostatic technique, and compared with that of the standard cast alloy of Ag‐Pd (Ney 76). The values of different parameters such as corrosion potential and corrosion current density were determined for the indigenous alloy of Ag‐Sn‐Cu and the Ag‐Pd alloy. The rate of corrosion of the indigenous alloy was found to be relatively higher than that of the Ag‐Pd alloy up to an applied potential of + 400 mV. However, while the indigenous alloy showed a distinct tendency for passivation below + 200 mV at the current level of 0·5 mA/cm2 in the artificial saliva (pH 5·7) at 37 °C, no such tendency for passivation was shown by the Ag‐Pd alloy even up to + 400 mV. The tendency for passivation by the indigenous Ag‐Sn‐Cu alloy, however, was not shown in the artificial saliva in the presence of 0·1
m
lactic acid (pH. 2·7) at 37 °C. Minor variation was observed in the corrosion behaviour of the indigenous Ag‐Sn‐Cu alloys of different grades prepared by alloying elements of varying purity.
In‐vitro solubility of three types of resin and conventional luting cements
Authors: Yoshida K. , Tanagawa M. , Atsuta M.
Published: January 2004

The solubility of resin luting cement remains unknown although the use of resin luting cement for routine cementation of restorations has increased. The purpose of this in‐vitro study was to compare the solubilities of three resin cements currently in clinical use with three brands of conventional luting agents. The three resin luting cements, All‐Bond C&B® (AB, Bisco) Panavia 21® (P21, Kuraray), and Super‐Bond C&B® (SB, Sun‐Medical), and the three conventional luting agents, Elite Cement 100® (EC, zinc phosphate cement, GC), HY‐Bond Carbo‐plus Cement® (HCP, polycarboxylate cement, Shofu), and Fuji I® (FI, glass‐ionomer cement, GC) were used in this study. A modification of the ADA specification test was adopted to evaluate the solubilities of luting cements. The two types of media (distilled water and pH 4·0 lactic acid solution) in which specimens were stored for 30 days were prepared. The four luting cements, EC, FI, AB, and P21, were more soluble in lactic acid solution than in distilled water. Resin luting cements were markedly less soluble than conventional luting agents when placed in fresh lactic acid solution (0·001 mol/L) at pH 4·0 every 24 h over a 30‐day period. The solubility rates of luting cements could be fitted to mathematical expressions which indicated that the solubilities increased linearly or logarithmically with immersion period. Fixed prosthodontic restorations cemented with resin luting cement may be capable of withstanding long‐term clinical use compared with conventional luting agents.
A novel temporary prostatic stent for the relief of prostatic urethral obstruction
Authors: Corica A.P. , Larson B.T. , Sagaz A. , Corica A.G. , Larson T.R.
Published: February 2004

OBJECTIVES

To determine the effect of a novel temporary prostatic stent (The SpannerTM, AbbeyMoor Medical, Inc., Minnesota, USA) on variables of voiding function and quality of life among patients with prostatic urethral obstruction.

PATIENTS AND METHODS

The stent design is very similar to the proximal 4–6 cm of a Foley catheter; this includes a proximal balloon to prevent distal displacement, a urine port situated cephalad to the balloon, and a reinforced stent of various lengths to span most of the prostatic urethra. There is also a distal anchor mechanism attached by sutures, and a retrieval suture which extends to the meatus and deflates the proximal balloon when pulled. The stent was inserted under topical anaesthesia in 30 patients. The maximum flow rate (Qmax), voided volume (VV), postvoid residual (PVR), the International Prostate Symptom Score (IPSS) and stent position were assessed.

RESULTS

Stents remained in situ for a mean (range) of 57 (1–98) days. The mean overall Qmax at baseline and after insertion were 8.2 and 11.6 mL/s, representing a 42% improvement (P < 0.001); the respective mean overall VVs were similar, at 219.7 and 221.6 mL (0.9% increase, not significant) and the PVRs were 312.1 and 112.3 mL, representing a 64% decrease (P = 0.004). The overall mean IPSS declined from 22.3 before to 7.1 after insertion, representing a 68% decrease (P < 0.001). There were only minor adverse events. The stability, patency and lack of migration of the device were confirmed radiographically up to 12 weeks of use.

CONCLUSIONS

This early study shows that this temporary prostatic stent is easily inserted and removed, remains anchored in position, and significantly improves the Qmax, PVR and IPSS while preserving volitional voiding and continence.
Orthotopic ileal neobladder: the influence of reservoir volume and configuration on urinary continence and emptying properties
Authors: Nesrallah L.J. , Srougi M. , Dall’oglio M.F.
Published: February 2004

The authors from Sao Paulo describe their experience with orthotopic urinary reservoirs using segments of intestine after radical cystectomy. They felt that orthotopic ileal neobladders with a spherical configuration were not associated with better continence rates and were prone to progressive enlargement, leading to atomy and progressive failure of emptying.

OBJECTIVE

To evaluate the influence of the volume and configuration of the neobladder on urinary continence and reservoir emptying in orthotopic urinary reservoirs using intestinal segments for bladder replacement after radical cystectomy.

PATIENTS AND METHODS

Fifty‐nine patients who had had a radical cystectomy and urinary reconstruction with an orthotopic ileal neobladder were followed for ≥ 1 year; 27 (group 1) had the ileal neobladder created with a shorter intestinal segment (40 cm) in an elongated shape (‘J’), and 32 (group 2) had their reservoir made more spherical with a longer ileal loop (60–65 cm). The rates of urinary continence, enuresis, neobladder capacity and postvoid residual urine were evaluated first at 3–6 months and again 1 year after surgery in both groups.

RESULTS

At 3–6 months after surgery urinary incontinence and enuresis were more common in group 1, but at 1 year had the same frequency in both groups, at respectively 11% and 44% in group 1, and 13% and 47% in group 2 (P > 0.05). The neobladder capacity and postvoid residual urine were significantly higher in group 2, at > 600 mL and > 100 mL, respectively, in 14% and 14% of the patients in group 1 and 57% and 52% of those in group 2 (P < 0.05). Urinary retention requiring intermittent catheterization did not occur in group 1 but did in 19% of group 2.

CONCLUSION

The orthotopic spherical ileal neobladder with a large initial volume is apparently not associated with better continence rates and is prone to developing progressive enlargement, which can lead to neobladder atony and progressive emptying failure, increasing the chance of complete urinary retention.
Modulation of autonomous contractile activity in the isolated whole bladder of the guinea pig
Authors: Gillespie J.I.
Published: February 2004

The over active bladder and bladder outlet obstruction represent clinically significant problems. The first two papers of this month's Scientific Discovery section addresses novel and exiting theories in this field. They also describe new models to investigate these complicated in vivo problems. Professor Gillespie describes that in addition to the neurogenic and myogenic hypothesis bladder over activity is a consequence of inappropriate activation or modulation of phasic activity: the autonomous bladder hypothesis. In his second paper he describes that noradrenaline inhibits autonomous activity in the isolated guinea pig bladder. Both papers add important information on the cellular mechanisms of bladder dysfunction.

OBJECTIVE

To investigate the actions of the nonhydrolysable analogue of ATP, α,β‐methylene ATP (α,β‐MATP) and the sensory peptide, substance P, on the phasic activity generated by muscarinic stimulation in the isolated whole bladder. Isolated bladder can generate complex contractions resulting in phasic rises in intravesical pressure (the autonomous bladder): activity thought to underlie nonmicturition activity in vivo and which may be important in generating bladder sensations.

MATERIALS AND METHODS

Experiments were conducted on whole isolated bladders from female guinea pigs (270–300 g). Bladders were cannulated via the urethra, suspended in a heated chamber containing oxygenated solution at 33–36 °C and intravesical pressure recorded. All drugs were added to the solution bathing the abluminal surface of the bladder.

RESULTS

When α,β‐MATP (30–3000 nmol/L) or substance P (30–300 nmol/L) was added to resting bladders there were small rises in intravesical pressure (<2 cmH2O). However, in the presence of phasic activity generated by exposing the bladder to the muscarinic agonist arecaidine (100–300 nmol/L) or the nicotinic ligand lobeline (10–30 µmol/L) similar or lower concentrations of α,β‐MATP or substance P produced more dramatic effects: α,β‐MATP and substance P (both at 100 nmol/L) activated a rise in basal pressure of > 15 cmH2O and increased the frequency of the phasic activity. On removing α,β‐MATP or substance P, there was a slowing of phasic activity indicative of an inhibitory mechanism.

CONCLUSION

In addition to direct effects on smooth muscle the agonists α,β‐MATP and substance P appear to be potent regulators of the mechanisms generating phasic activity. A developing concept is that the mechanisms responsible for generating phasic activity underlie nonmicturition activity are the target for excitatory and inhibitory inputs. Regulating such activity may be a factor in generating or modifying bladder sensation. Inappropriate or exaggerated phasic activity could underpin the pathological changes which cause the overactive bladder, thus adding another hypothesis to the neurogenic and myogenic hypotheses of bladder overactivity, i.e. that of the autonomous bladder.
Noradrenaline inhibits autonomous activity in the isolated guinea pig bladder
Authors: Gillespie J.I.
Published: February 2004

OBJECTIVE

To investigate the actions of noradrenaline and the specific α‐adrenergic agonists cirazoline (α1) and UK14304 (α2), and β‐receptor agonists formoterol (β2) and BRL37344 (β3) on the phasic activity induced by muscarinic stimulation on the isolated guinea pig bladder, as the physiological significance of this activity is unknown but it may underlie non‐micturition contractions (NMCs, which can be inhibited by sympathetic nerve stimulation) and the generation of bladder sensations.

MATERIALS AND METHODS

All experiments were conducted using whole isolated bladders from female guinea pigs (270–300 g). Bladders were cannulated via the urethra and suspended in a heated chamber containing oxygenated Tyrode's solution at 33–35 °C and the intravesical pressure recorded. All drugs were added to the solution bathing the abluminal surface.

RESULTS

Exposure to noradrenaline reduced the amplitude and frequency of the phasic activity When noradrenaline was washed off there was a transient increase in frequency. There was marked desensitization with repeated applications of noradrenaline. Applying the specific β3‐agonist BRL37344 reduced the amplitude of the phasic activity while formoterol, a specific β2‐agonist, had no effect. Cirazoline, a specific α1‐agonist, reduced the amplitude of the responses and significantly reduced the frequency of the phasic activity. UK14304, a specific α2‐agonist, had no effect. Stimulation of the hypogastric nerve to the guinea pig bladder generates contractions. Prolonged nerve stimulation at low frequency (6.5 Hz) generated phasic rises in intravesical pressure which were inhibited by noradrenaline. Using short (5 s) periods of stimulation noradrenaline inhibited nerve‐mediated contractions at all frequencies but was more effective at <10 Hz.

CONCLUSION

These experiments show that sympathomimetic stimulation in the isolated whole bladder results primarily in an inhibition of phasic activity, but also a stimulation. Two receptor subtypes appear to be involved in the inhibition, α1 and β3, suggesting that there may be many sites of action. These results are discussed in terms of the possible physiological significance of phasic activity and the potential importance of its inhibition, in the context of the causes of pathological changes in the bladder, particularly those associated with bladder overactivity, and the pharmacological approach to the alleviation of clinical symptoms.
The effect of sampling more cores on the predictive accuracy of pathological grade and tumour distribution in the prostate biopsy
Authors: Makhlouf A.A. , Krupski T.L. , Kunkle D. , Theodorescu D.
Published: February 2004

The technique for taking prostatic biopsies has received a major evaluation from many departments around the world in terms of the number of cores, site of biopsy, complications, need for local anaesthesia or sedation, etc., and the authors from Charlottesville review their technique. They present data confirming the impression that increasing the number of cores increases diagnostic sensitivity.

Authors from Chapel Hill have performed a pilot study into the concept that cyclooxygenase (COX)‐2 inhibitors inhibit tumour growth in prostate cancer, both in vivo and in vitro. In a few patients they found evidence to suggest that COX‐2 inhibitors may be of value in patients with prostate cancer, concluding that a large trial is indicated.

Vascular endothelial growth factor (VEGF) is known to be an important angiogenic factor. The authors from Sweden assessed its value as a marker in renal cancer cells. They found it to be present in most such cells, and found that the correlation between VEGF expression and tumour stage and prognosis was valuable in terms of progression of renal cancer.

OBJECTIVE

To determine if increasing the number of cores at biopsy improves the predictive accuracy of the Gleason score or aids in anticipating the location and volume of prostate tumour.

PATIENTS AND METHODS

The charts of 75 consecutive patients who underwent radical retropubic prostatectomy for clinical T1–2 adenocarcinoma of the prostate were reviewed retrospectively; 31 patients had a sextant biopsy (group 1) and 44 had ≥ 8 cores taken (group 2). The concordance between biopsy data and final prostatectomy Gleason score, tumour location and volume was determined for each group.

RESULTS

There were no differences in mean age, prostate‐specific antigen level before biopsy or biopsy Gleason score for the two groups; 58% of group 1 had their final pathological grade changed after prostatectomy, vs 29% of group 2 (P < 0.05). In neither group was there a significant correlation between the percentage of cores positive for tumour and the percentage volume of prostate involved with cancer, or the ability of the biopsy to predict tumour location.

CONCLUSION

Taking ≥ 8 biopsy cores improved the pathological grading accuracy, which may be valuable in choosing a treatment for the patient with newly diagnosed prostate cancer.
On the saliency of negative stimuli: Evidence from attentional blink1
Authors: Ogawa Tokihiro , Suzuki Naoto
Published: January 2004

Abstract:  When people are asked to detect two targets from a rapid serial visual presentation (RSVP) stream, impairment of recognition of the second target (T2) can be observed if the T2 is presented several hundred milliseconds later than the first target (T1). This phenomenon is known as attentional blink, and is considered to reflect some temporal characteristic of the attentional process. The aim of the present study was to use the attentional blink paradigm to examine whether the affective meaning of the stimuli could affect the magnitude of attentional blink. In Experiment 1, the valence of the T2 (neutral, positive, and negative) was manipulated. Significant T2 detection deficit was observed with neutral and positive T2 but not with negative T2. Experiment 2 demonstrated that non‐significant attentional blink in negative T2 in Experiment 1 could be attributed to the negative affective meaning of T2. Results are discussed in terms of the high saliency of negative information.
Water can induce better spatial memory performance than food in radial maze learning by rats1
Authors: Komaki Junji
Published: January 2004

Abstract:  Two experiments were carried out to test the differential effects of hunger and thirst on memory performance. In Experiment 1, two groups of rats were exposed to an original radial‐maze task and then to a 30‐min retention‐memory task. The food‐deprived group completed the original task more quickly than the water‐deprived group, but the thirsty group mastered the memory task more quickly than the hungry group (p < 0.01). In Experiment 2, deprivation conditions were changed from the original to the memory task. The food‐water group completed the memory task more rapidly than the water‐food group (p < 0.05). Thirst proved to constitute a more favorable condition for retention‐memory learning. The applicability of several theories is discussed.
Changing Homeowners’ Behaviors Involving Toxic Household Chemicals: A Psychological, Multilevel Approach
Authors: Werner Carol M. , Adams Dorothy
Published: January 2004

We describe an education and behavior change program with a multi‐level approach. The program goal is to change how people think about, use, store, and dispose of toxic household chemicals. We assume that changing long‐standing behaviors is difficult, requires interventions at multiple points in the individual/group/society/physical environmental system, and requires interventions that address both short‐ and long‐term behavior change. The heart of our program is small group discussions, with a trained leader who uses psychological theories to increase educational impact. Questionnaires indicated that participants were very pleased with the program, especially recipes for homemade nontoxic alternatives. We estimate that the presentation yielded almost three times as much cooperation as the previous 5 years of publicity and promotion (33% vs. 12%).
Siberian Peatlands a Net Carbon Sink and Global Methane Source Since the Early Holocene
Authors: Smith L. C. , MacDonald G. M. , Velichko A. A. , Beilman D. W. , Borisova O. K. , Frey K. E. , Kremenetski K. V. , Sheng Y.
Published: January 2004

Interpolar methane gradient (IPG) data from ice cores suggest the “switching on” of a major Northern Hemisphere methane source in the early Holocene. Extensive data from Russia's West Siberian Lowland show (i) explosive, widespread peatland establishment between 11.5 and 9 thousand years ago, predating comparable development in North America and synchronous with increased atmospheric methane concentrations and IPGs, (ii) larger carbon stocks than previously thought (70.2 Petagrams, up to ∼26% of all terrestrial carbon accumulated since the Last Glacial Maximum), and (iii) little evidence for catastrophic oxidation, suggesting the region represents a long-term carbon dioxide sink and global methane source since the early Holocene.
Community Assembly Through Adaptive Radiation in Hawaiian Spiders
Authors: Gillespie Rosemary
Published: January 2004

Communities arising through adaptive radiation are generally regarded as unique, with speciation and adaptation being quite different from immigration and ecological assortment. Here, I use the chronological arrangement of the Hawaiian Islands to visualize snapshots of evolutionary history and stages of community assembly. Analysis of an adaptive radiation of habitat-associated, polychromatic spiders shows that (i) species assembly is not random; (ii) within any community, similar sets of ecomorphs arise through both dispersal and evolution; and (iii) species assembly is dynamic with maximum species numbers in communities of intermediate age. The similar patterns of species accumulation through evolutionary and ecological processes suggest universal principles underlie community assembly.
Infinite Confusion
Authors: Rucker Rudy
Published: January 2004

Everything and More
A Compact History of ∞. by David Foster Wallace. Norton, New York, 2003. 331 pp. $23.95, C$36. ISBN 0-393-00338-8. Weidenfeld and Nicolson, London, 2003. £14.99. ISBN 0-297-64567-6.

With his characteristic wild style, Wallace presents an account of our attempts to understand infinity. In particular, he hopes to lead readers to an appreciation for the accomplishments of Georg Cantor.
Biological, Epidemiological, and Clinical Aspects of Echinococcosis, a Zoonosis of Increasing Concern
Authors: Eckert Johannes , Deplazes Peter
Published: January 2004

Echinococcosis in humans is a zoonotic infection caused by larval stages (metacestodes) of cestode species of the genus Echinococcus. Cystic echinococcosis (CE) is caused by Echinococcus granulosus, alveolar echinococcosis (AE) is caused by E. multilocularis, and polycystic forms are caused by either E. vogeli or E. oligarthrus. In untreated cases, AE has a high mortality rate. Although control is essentially feasible, CE remains a considerable health problem in many regions of the northern and southern hemispheres. AE is restricted to the northern hemisphere regions of North America and Eurasia. Recent studies have shown that E. multilocularis, the causative agent of AE, is more widely distributed than previously thought. There are also some hints of an increasing significance of polycystic forms of the disease, which are restricted to Central and South America. Various aspects of human echinococcosis are discussed in this review, including data on the infectivity of genetic variants of E. granulosus to humans, the increasing invasion of cities in Europe and Japan by red foxes, the main definitive hosts of E. multilocularis, and the first demonstration of urban cycles of the parasite. Examples of emergence or reemergence of CE are presented, and the question of potential spreading of E. multilocularis is critically assessed. Furthermore, information is presented on new and improved tools for diagnosing the infection in final hosts (dogs, foxes, and cats) by coproantigen or DNA detection and the application of molecular techniques to epidemiological studies. In the clinical field, the available methods for diagnosing human CE and AE are described and the treatment options are summarized. The development of new chemotherapeutic options for all forms of human echinococcosis remains an urgent requirement. A new option for the control of E. granulosus in the intermediate host population (mainly sheep and cattle) is vaccination. Attempts are made to reduce the prevalence of E. multilocualaris in fox populations by regular baiting with an anthelmintic (praziquantel). Recent data have shown that this control option may be used in restricted areas, for example in cities, with the aim of reducing the infection risk for humans.
Pathogenicity Islands in BacterialPathogenesis
Authors: Schmidt Herbert , Hensel Michael
Published: January 2004

In this review, we focus on a group of mobile genetic elements designated pathogenicity islands (PAI). These elements play a pivotal role in the virulence of bacterial pathogens of humans and are also essential for virulence in pathogens of animals and plants. Characteristic molecular features of PAI of important human pathogens and their role in pathogenesis are described. The availability of a large number of genome sequences of pathogenic bacteria and their benign relatives currently offers a unique opportunity for the identification of novel pathogen-specific genomic islands. However, this knowledge has to be complemented by improved model systems for the analysis of virulence functions of bacterial pathogens. PAI apparently have been acquired during the speciation of pathogens from their nonpathogenic or environmental ancestors. The acquisition of PAI not only is an ancient evolutionary event that led to the appearance of bacterial pathogens on a timescale of millions of years but also may represent a mechanism that contributes to the appearance of new pathogens within a human life span. The acquisition of knowledge about PAI, their structure, their mobility, and the pathogenicity factors they encode not only is helpful in gaining a better understanding of bacterial evolution and interactions of pathogens with eukaryotic host cells but also may have important practical implications such as providing delivery systems for vaccination, tools for cell biology, and tools for the development of new strategies for therapy of bacterial infections.
Theiler's Virus Infection: a Model for Multiple Sclerosis
Authors: Oleszak Emilia L. , Chang J. Robert , Friedman Herman , Katsetos Christos D. , Platsoucas Chris D.
Published: January 2004

Both genetic background and environmental factors, very probably viruses, appear to play a role in the etiology of multiple sclerosis (MS). Lessons from viral experimental models suggest that many different viruses may trigger inflammatory demyelinating diseases resembling MS. Theiler's virus, a picornavirus, induces in susceptible strains of mice early acute disease resembling encephalomyelitis followed by late chronic demyelinating disease, which is one of the best, if not the best, animal model for MS. During early acute disease the virus replicates in gray matter of the central nervous system but is eliminated to very low titers 2 weeks postinfection. Late chronic demyelinating disease becomes clinically apparent approximately 2 weeks later and is characterized by extensive demyelinating lesions and mononuclear cell infiltrates, progressive spinal cord atrophy, and axonal loss. Myelin damage is immunologically mediated, but it is not clear whether it is due to molecular mimicry or epitope spreading. Cytokines, nitric oxide/reactive nitrogen species, and costimulatory molecules are involved in the pathogenesis of both diseases. Close similarities between Theiler's virus-induced demyelinating disease in mice and MS in humans, include the following: major histocompatibility complex-dependent susceptibility; substantial similarities in neuropathology, including axonal damage and remyelination; and paucity of T-cell apoptosis in demyelinating disease. Both diseases are immunologically mediated. These common features emphasize the close similarities of Theiler's virus-induced demyelinating disease in mice and MS in humans.
ISSa4-Based Differentiation of
Streptococcus agalactiae
Strains and Identification of Multiple Target Sites for ISSa4 Insertions
Authors: Dmitriev Alexander , Shen Adong , Shen Xuzhuang , Yang Yonghong
Published: February 2004

A collection of 113 epidemiologically unrelated
Streptococcus agalactiae
strains were studied (group B streptococcus; GBS): they belonged to different serotypes and were isolated from pregnant women in China and Russia. The insertion sequence ISSa4 was found in 21 of 113 strains (18,6%). All of the strains with ISSa4 belonged to serotypes II and II/c and were characterized by the presence of IS
1381
and IS
861
as well as the absence of IS
1548
and GBSi1. All of the strains with ISSa4 possessed both
bca
and
bac
virulence genes coding for α and β antigens, respectively. Among 21 ISSa4-positive strains, 13 different
Hin
dIII patterns (D1 to D13) hybridizing with an ISSa4 probe were found. One of them (D13) contained a single
Hin
dIII hybridization fragment 6.5 kb in size that was found to be specific for all ISSa4-positive GBS strains. Multiple target sites for insertions of ISSa4 were identified and included a putative pathogenicity island, “housekeeping” genes, and intergenic regions, as well as the genes for hypothetical proteins. No significant similarity was observed in the sequences of the target genes for ISSa4 insertions, in the relative location of the target genes on the chromosome, or the biological functions of the encoded proteins. The possible significance of ISSa4-based differentiation of the strains and the presence of possible “hot spots” for insertions of ISSa4 in GBS genome are discussed.
Transcriptional Regulation of thephoPROperon inBacillus subtilis
Authors: Prágai Zoltán , Allenby Nicholas E. E. , O'Connor Nicola , Dubrac Sarah , Rapoport Georges , Msadek Tarek , Harwood Colin R.
Published: February 2004

WhenBacillus subtilisis subjected to phosphate starvation, the Pho regulon is activated by the PhoP-PhoR two-component signal transduction system to elicit specific responses to this nutrient limitation. The response regulator, PhoP, and its cognate histidine sensor kinase, PhoR, are encoded by thephoPRoperon that is transcribed as a 2.7-kb bicistronic mRNA. ThephoPRoperon is transcribed from two σA-dependent promoters, P1and P2. Under conditions where the Pho regulon was not induced (i.e., phosphate-replete conditions orphoR-null mutant), a low level ofphoPRtranscription was detected only from promoter P1. During phosphate starvation-induced transition from exponential to stationary phase, the expression of thephoPRoperon was up-regulated in a phosphorylated PhoP (PhoP∼P)-dependent manner; in addition to P1, the P2promoter becomes active. In vitro gel shift assays and DNase I footprinting experiments showed that both PhoP and PhoP∼P could bind to the control region of thephoPRoperon. The data indicate that while low-level constitutive expression ofphoPRis required under phosphate-replete conditions for signal perception and transduction, autoinduction is required to provide sufficient PhoP∼P to induce other members of the Pho regulon. The extent to which promoters P1and P2are activated appears to be influenced by the presence of other sigma factors, possibly the result of sigma factor competition. For example,phoPRis hyperinduced in asigBmutant and, later in stationary phase, insigH,sigF, andsigEmutants. The data point to a complex regulatory network in which other stress responses and post-exponential-phase processes influence the expression ofphoPRand, thereby, the magnitude of the Pho regulon response.
Novel Roles of the Master Transcription Factors Spo0A and σBfor Survival and Sporulation ofBacillus subtilisat Low Growth Temperature
Authors: Méndez Marcelo B. , Orsaria Lelia M. , Philippe Valeria , Pedrido María Eugenia , Grau Roberto R.
Published: February 2004

Spore development and stress resistance inBacillus subtilisare governed by the master transcription factors Spo0A and σB, respectively. Here we show that the coding genes for both regulatory proteins are dramatically induced, during logarithmic growth, after a temperature downshift from 37 to 20°C. The loss of σBreduces the stationary-phase viability of cold-adapted cells 10- to 50-fold. Furthermore, we show that σBactivity is required at a late stage of development for efficient sporulation at a low temperature. On the other hand, Spo0A loss dramatically reduces the stationary-phase viability of cold-adapted cells 10,000-fold. We show that the requirement of Spo0A for cellular survival during the cold is independent of the activity of the key transition state regulator AbrB and of the simple loss of sporulation ability. Furthermore, Spo0A, and not proficiency in sporulation, is required for the development of complete stress resistance of cold-adapted cells to heat shock (54°C, 1 h), since a loss of Spo0A, but not a loss of the essential sporulation transcription factor σF, reduced the cellular survival in response to heat by more than 1,000-fold. The overall results argue for new and important roles for Spo0A in the development of full stress resistance by nonsporulating cells and for σBin sporulation proficiency at a low temperature.
Insulin resistance of gluconeogenic pathways in neonatal rats after prenatal ethanol exposure
Authors: Chen Li , Zhang Tong , Nyomba B. L. G.
Published: February 2004

Alcohol exposure during pregnancy is associated with fetal growth restriction and programs the offspring to insulin resistance later in life. The underlying mechanisms are still uncertain, but a dysregulation of gluconeogenesis and adipose hormones may be contributory. Newborn rats from dams that had been given ethanol (EtOH) or water (controls) during pregnancy were studied. Adiponectin mRNA was determined in subcutaneous fat by RT-PCR, and serum adiponectin was measured by RIA. Subsets of rats were killed before and after intraperitoneal administration of insulin, to determine, by RT-PCR, the hepatic expression of gluconeogenic enzymes and that of the transcription factor peroxisome proliferator-activated receptor-coactivator (PGC)-1, which promotes gluconeogenesis. EtOH offspring had delayed hypoglycemic response to insulin but normal adiponectin mRNA and serum levels compared with controls. The inhibitory response of the gluconeogenic enzyme phospho enol- pyruvate carboxykinase (PEPCK) and PGC-1 mRNAs to insulin was blunted in EtOH offspring compared with controls. The data suggest that intrauterine EtOH exposure causes insulin resistance of genes for PGC-1 and PEPCK early in life.
γ-MSH, sodium metabolism, and salt-sensitive hypertension
Authors: Humphreys Michael H.
Published: February 2004

α-, β-, and γ-melanocyte stimulating hormones (MSHs) are melanotropin peptides that are derived from the ACTH/β-endorphin prohormone proopiomelanocortin (POMC). They have been highly conserved through evolutionary development, although their functions in mammals have remained obscure. The identification in the last decade of a family of five membrane-spanning melanocortin receptors (MC-Rs), for which the melanotropins are the natural ligands, has permitted the characterization of a number of important actions of these peptides, although the physiological function(s) of γ-MSH have remained elusive. Much evidence indicates that γ-MSH stimulates sympathetic outflow and raises blood pressure through a central mechanism. However, this review focuses on newer cardiovascular and renal actions of the peptide, acting in most cases through the MC3-R. In rodents, a high-sodium diet (HSD) increases the pituitary abundance of POMC mRNA and of γ-MSH content and results in a doubling of plasma γ-MSH concentration. The peptide is natriuretic and acts through renal MC3-Rs, which are also upregulated by the HSD. Thus the system appears designed to participate in the integrated response to dietary sodium excess. Genetic or pharmacologic induction of γ-MSH deficiency results in marked salt-sensitive hypertension that is corrected by the administration of the peptide, probably through a central site of action. Deletion of the MC3-R also produces salt-sensitive hypertension, which, however, is not corrected by infusion of the hormone. These observations in aggregate suggest the operation of a hormonal system important in blood pressure control and in the regulation of sodium excretion. The relationship of these two actions to each other and the significance of this system in humans are important questions for future research.
Mitochondrial dysfunction in a long-term rodent model of sepsis and organ failure
Authors: Brealey David , Karyampudi Sekhar , Jacques Thomas S. , Novelli Marco , Stidwill Ray , Taylor Val , Smolenski Ryszard T. , Singer Mervyn
Published: February 2004

Although sepsis is the major cause of mortality and morbidity in the critically ill, precise mechanism(s) causing multiorgan dysfunction remain unclear. Findings of impaired oxygen utilization in septic patients and animals implicate nitric oxide-mediated inhibition of the mitochondrial respiratory chain. We recently reported a relationship between skeletal muscle mitochondrial dysfunction, clinical severity, and poor outcome in patients with septic shock. We thus developed a long-term, fluid-resuscitated, fecal peritonitis model utilizing male Wistar rats that closely replicates human physiological, biochemical, and histological findings with a 40% mortality. As with humans, the severity of organ dysfunction and eventual poor outcome were associated with nitric oxide overproduction and increasing mitochondrial dysfunction (complex I inhibition and ATP depletion). This was seen in both vital (liver) and nonvital (skeletal muscle) organs. Likewise, histological evidence of cell death was lacking, suggesting the possibility of an adaptive programmed shutdown of cellular function. This study thus supports the hypothesis that multiorgan dysfunction induced by severe sepsis has a bioenergetic etiology. Despite the well-recognized limitations of laboratory models, we found clear parallels between this long-term model and human disease characteristics that will facilitate future translational research.
Kinematic Analysis of Manual Tracking in Monkeys: Characterization of Movement Intermittencies During a Circular Tracking Task
Authors: Roitman A. V. , Massaquoi S. G. , Takahashi K. , Ebner T. J.
Published: February 2004

Segmentation of the velocity profiles into the submovements has been observed in reaching and tracking limb movements and even in isometric tasks. Submovements have been implicated in both feed-forward and feedback control. In this study, submovements were analyzed during manual tracking in the nonhuman primate with the focus on the amplitude-duration scaling of submovements and the error signals involved in their control. The task consisted of the interception and visually guided pursuit of a target moving in a circle. The submovements were quantified based on their duration and amplitude in the speed profile. Control experiments using passive movements demonstrated that these intermittencies were not instrumentation artifacts. Submovements were prominent in both the interception and tracking phases and their amplitude scaled linearly with duration. The scaling factors increased with tracking speed at the same rate for both interception and pursuit. A cross-correlation analysis between a variety of error signals and the speed profile revealed that direction and speed errors were temporally coupled to the submovements. The cross-correlation profiles suggest that submovements are initiated when speed error reaches a certain limit and when direction error is minimized. The scaling results show that in monkeys submovements characterize both the interception and pursuit portions of the task and that these submovements have similar scaling properties consistent with 1) the concept of stereotypy and 2) adding constant acceleration/force at a specific tracking speed. The correlation results show involvement of speed and direction error signals in controlling the submovements.
Novel Form of Long-Term Synaptic Depression in Rat Hippocampus Induced By Activation of α1 Adrenergic Receptors
Authors: Scheiderer Cary L. , Dobrunz Lynn E. , McMahon Lori L.
Published: February 2004

Neurons located in the locus coeruleus project to hippocampus and provide noradrenergic innervation necessary for hippocampal-dependent learning and memory. The mechanisms underlying the function of norepinephrine (NE) in memory processing are unknown but likely reside in the ability of NE to modulate the efficacy of glutamate synaptic transmission via activation of G-protein-coupled adrenergic receptors. Here we show that application of NE to rat hippocampal slices in vitro induces a long-term depression (LTD) of synaptic transmission at excitatory CA3–CA1 synapses that persists for ≥40 min after agonist washout. This LTD, which we refer to as NE LTD, is mediated by activation of α1 adrenergic receptors because the α1 agonist methoxamine can induce LTD at the same magnitude as that induced with the nonselective adrenergic agonist NE. Furthermore, NE LTD induced by either NE or methoxamine is blocked with the α1 receptor antagonist, prazosin, but is unaffected by antagonists of α2 and β receptors. This plasticity persists in the presence of the GABAA receptor antagonist bicuculline, indicating that adrenergic modulation of GABAA receptor-mediated transmission does not underlie NE LTD. Induction of NE LTD requires presynaptic activity during agonist application and postsynaptic activation of N-methyl-d-aspartate receptors, fulfilling Hebbian criteria of coincident pre- and postsynaptic activity. The expression of NE LTD is likely to be postsynaptic because paired-pulse facilitation ratios during NE LTD expression are not different from baseline, similar to LTD induced by low-frequency stimulation. Thus we report the identification and characterization of a novel Hebbian form of LTD in hippocampus that is induced after activation of α1 adrenergic receptors. This plasticity may be a mechanism by which the adrenergic system participates in normal cognitive function.
Differential Cortical and Subcortical Activations in Learning Rotations and Gains for Reaching: A PET Study
Authors: Krakauer John W. , Ghilardi Maria-Felice , Mentis Marc , Barnes Anna , Veytsman Milana , Eidelberg David , Ghez Claude
Published: February 2004

Previous studies suggest that horizontal reaching movements are planned vectorially with independent specification of direction and extent. The transformation from visual to hand-centered coordinates requires the learning of a task-specific reference frame and scaling factor. We studied learning of a novel reference frame by imposing a screen-cursor rotation and learning of a scaling factor by imposing a novel gain. Previous work demonstrates that rotation and gain learning have different time courses and patterns of generalization. Here we used PET to identify and compare brain areas activated during rotation and gain learning, with a baseline motor-execution task as the subtracted control. Previous work has shown that the time courses of rotation and gain adaptation have a short rapid phase followed by a longer slow phase. We therefore also sought to compare activations associated with the rapid and slower phases of adaptation. We isolated the rapid phase by alternating opposite values of the rotation or gain every 16 movements. The rapid phase of rotation adaptation activated the preSMA. More complete adaptation to the rotation activated right ventral premotor cortex, right posterior parietal cortex, and the left lateral cerebellum. The rapid phase of gain learning only activated subcortical structures: bilateral putamen and left cerebellum. More complete gain learning failed to show any significant activation. We conclude that the time course of rotation adaptation is paralleled by a frontoparietal shift in activated cortical regions. In contrast, early gain adaptation involves only subcortical structures, which we suggest reflects a more automatic process of contextual recalibration of a scaling factor.
SONS AND MOTHERS IN WARRING STATES AND HAN CHINA, 453 BCE-220 CE
Authors: Brown Miranda
Published: January 2004

This article examines the startling attention accounts of Eastern Han (24-220 CE) mourning give to depictions of the mother-son bond. Such attention can be explained in terms of the rise of cultural stereotypes about the bonds between mothers and sons, as well as fathers and sons, from the first century BCE. Whereas elite thinkers and statesmen claimed that the relationship between fathers and sons was more analogous to official duty, they regarded the relationship between mother and son as emotional, personal (si), and close (qin). As such, the mother-son bond came to represent an ideological alternative to the early Han ethos of official service, an ethos epitomized by the slogan, "duty to lord and father" (junfu zhi yi).
BONDING, BENEVOLENCE, BARTER, AND BRIBERY: IMAGES OF FEMALE GIFT EXCHANGE IN THE JIN PING MEI
Authors: Dauncey Sarah
Published: January 2004

This article examines images of the practice of gift exchange among women in the late Ming. Despite the fact that the majority of orthodox historical and didactic sources overlook such activity among women, other sources such as the novel Jin Ping Mei reveal perceptions that gift-giving practices were common among women and could be used to facilitate many forms of social action. While highlighting the more mundane use of gifts in lieu of cash and the darker aspect of gift exchange for bribery, the fictional world of the Jin Ping Mei also reflects the socially significant practices of dowry preparation, betrothal gift presentation, and the everyday exchange of gifts to develop friendships and relationships.
The integrated use of chemical insecticides and the entomopathogenic nematode, Steinernema feltiae, for the control of sweetpotato whitefly, Bemisia tabaci
Authors: Cuthbertson Andrew , Head Justine , Walters Keith , Murray Alistair
Published: February 2004

The integration of infective juveniles of the entomopathogenic nematode, Steinernema feltiae, with chemical insecticides to control second instar stages of the sweetpotato whitefly, Bemisia tabaci, was investigated. The effects of direct exposure for 24 h to field rate dilutions of four insecticides (imidacloprid, buprofezin, teflubenzuron and nicotine) on nematode infectivity to Galleria mellonella larvae were tested in a sand tube bioassay. Teflubenzuron had the least adverse effect on the nematodes whilst imidacloprid, buprofezin and nicotine significantly reduced nematode infectivity. The impact of dry insecticide residue present on tomato and verbena foliage on nematode infectivity against B. tabaci larvae was investigated for buprofezin, teflubenzuron and nicotine (imidacloprid is a systemic pesticide and no residues would occur on foliage). No significant reduction on the level of control of B. tabaci was recorded when compared with the infectivity of nematodes applied to residue-free foliage of either tomato or verbena plants. Nematodes in combination with imidacloprid gave significantly higher B. tabaci larvae mortality compared to either treatment individually on both host plants. The integration of S. feltiae and these chemical agents into an integrated pest management programme for the control of B. tabaci is discussed.