bluuebunny/crossref_metadata_2025 huggingface dataset:
Transfer of adaptation from visually guided saccades to averaging saccades elicited by double visual targets
Authors: Alahyane Nadia , Koene Ansgar , Pélisson Denis
Published: July 2004

The adaptive mechanisms that control the amplitude of visually guided saccades (VGS) are only partially elucidated. In this study, we investigated, in six human subjects, the transfer of VGS adaptation to averaging saccades elicited by the simultaneous presentation of two visual targets. The generation of averaging saccades requires the transformation of two representations encoding the desired eye displacement toward each of the two targets into a single representation encoding the averaging saccade (averaging programming site). We aimed to evaluate whether VGS adaptation acts upstream (hypothesis 1) or at/below (hypothesis 2) the level of averaging saccades programming. Using the double‐step target paradigm, we simultaneously induced a backward adaptation of 17.5° horizontal VGS and a forward adaptation of 17.5° oblique VGS performed along the ± 40° directions relative to the azimuth. We measured the effects of this dual adaptation protocol on averaging saccades triggered by two simultaneous targets located at 17.5° along the ± 40° directions. To increase the yield of averaging saccades, we instructed the subjects to move their eyes as fast as possible to an intermediate position between the two targets. We found that the amplitude of averaging saccades was smaller after VGS adaptation than before and differed significantly from that predicted by hypothesis 1, but not by hypothesis 2, with an adaptation transfer of 50%. These findings indicate that VGS adaptation largely occurs at/below the averaging saccade programming site. Based on current knowledge of the neural substrate of averaging saccades, we suggest that VGS adaptation mainly acts at the level of the superior colliculus or downstream.
Resistance to extinction is associated with impaired immediate early gene induction in medial prefrontal cortex and amygdala
Authors: Herry Cyril , Mons Nicole
Published: July 2004

Extinction of classical fear conditioning is thought to involve activity‐dependent potentiation of synaptic transmission in the medial prefrontal cortex (mPFC), resulting in the inhibition of amygdala‐dependent fear responses. While many studies have addressed the mechanisms underlying extinction learning, it is unclear what determines whether extinction memory is consolidated or whether spontaneous recovery of the fear response occurs. Here we show, using a combined electrophysiological and immunocytochemical approach, that spontaneous recovery of conditioned fear in mice is associated with a prolonged expression of long‐term depression of synaptic transmission in the mPFC and the failure of induction of the immediate–early genesc‐Fos and zif268 in the mPFC and the basolateral nucleus of the amygdala. This suggests that coordinated activity‐dependent changes in gene expression in the mPFC and the amygdala may underlie the formation of long‐term fear extinction memory.
Familial risk of prostate cancer in Iceland
Authors: Eldon B.J. , Jonsson E. , Tomasson J. , Tryggvadottir L. , Tulinius H.
Published: July 2004

OBJECTIVE

To estimate the risk of prostate and other types of cancer among relatives of Icelandic men diagnosed with prostate cancer over a 5‐year period.

PATIENTS AND METHODS

The risk ratio (RR) was used to estimate the risk among relatives of 371 patients with prostate cancer, all of whom lived in Iceland and were diagnosed when alive over a 5‐year interval (1983–7). Information on cancer incidence was obtained from the population‐based Icelandic Cancer Registry, and information on families from a comprehensive genealogical database covering the population of Iceland.

RESULTS

First‐degree male relatives were at a 1.7‐fold greater age‐adjusted risk of prostate cancer (1832 men; 95% confidence interval, CI, 1.28–2.34). The risk was independent of proband's age at diagnosis. First‐degree male relatives of patients who died from prostate cancer were at a statistically significantly greater risk of the disease (784 men; RR 2.17; 95% CI 1.34–3.53) and relatives of patients with incidental disease (T1a) were at a greater risk but not statistically significant so (261; RR 1.86; 95% CI 0.75–4.58). Female first‐degree relatives were not at greater risk of breast cancer. The risk of kidney cancer was higher in first‐ and second‐degree female relatives, with an RR (n, CI) of 2.50 (1780, 1.10–5.66) and 2.67 (5534, 1.04–6.81), respectively. The risk of kidney cancer was not statistically significantly greater in male relatives.

CONCLUSION

Family history is a risk factor for prostate cancer in Icelandic men. The risk is potentially higher for relatives of patients who die from the disease. Female relatives are not at greater risk of breast cancer but they may be at greater risk of kidney cancer.
Anti‐dumping Protection in a Liberalising Country: Mexico's Anti‐dumping Policy and Practice
Authors: Niels Gunnar , Ten Kate Adriaan
Published: July 2004

The use of anti‐dumping policy has been steadily growing in recent decades, and so has the theoretical and empirical literature on anti‐dumping. However, while developing countries as a whole have become at least as active as the ‘traditional’ anti‐dumping regimes (the USA, the EU, Canada and Australia), the literature is almost exclusively concerned with the latter group. This article gives an overview of anti‐dumping policy and practice in Mexico, one of the leading ‘new’ anti‐dumping regimes. It assesses how anti‐dumping has expanded since the country began liberalising trade in the mid‐1980s, and discusses how the policy has been applied in a protectionist way that is not dissimilar to policy practice in the traditional user countries.
Membrane properties of type II spiral ganglion neurones identified in a neonatal rat cochlear slice
Authors: Jagger Daniel J. , Housley Gary D.
Published: July 2004

Neuro‐anatomical studies in the mammalian cochlea have previously identified a subpopulation of approximately 5% of primary auditory neurones, designated type II spiral ganglion neurones (sgnII). These neurones project to outer hair cells and their supporting cells, within the ‘cochlear amplifier’ region. Physiological characterization of sgnII has proven elusive. Whole‐cell patch clamp of spiral ganglion neurones in P7‐P10 rat cochlear slices provided functional characterization of sgnII, identified by biocytin or Lucifer yellow labelling of their peripheral neurite projections (outer spiral fibres) subsequent to electrophysiological characterisation. SgnII terminal fields comprised multiple outer hair cells and supporting cells, located up to 370 μm basal to their soma. SgnII firing properties were defined by rapidly inactivating A‐type‐like potassium currents that suppress burst firing of action potentials. Type I spiral ganglion neurones (sgnI), had shorter radial projections to single inner hair cells and exhibited larger potassium currents with faster activation and slower inactivation kinetics, compatible with the high temporal firing fidelity seen in auditory nerve coding. Based on these findings, sgnII may be identified in future by the A‐type current. Glutamate‐gated somatic currents in sgnII were more potentiated by cyclothiazide than those in sgnI, suggesting differential AMPA receptor expression. ATP‐activated desensitising inward currents were comparable in sgn II and sgnI. These data support a role for sgnII in providing integrated afferent feedback from the cochlear amplifier.
Comparison of ultrasound and magnetic resonance imaging in 100 singleton pregnancies with suspected brain abnormalities
Authors: Whitby E.H. , Paley M.N.J. , Sprigg A. , Rutter S. , Davies N.P. , Wilkinson I.D. , Griffiths P.D.
Published: July 2004

Objective  To compare the diagnostic accuracy of the current reference standard‐ultrasound with in utero magnetic resonance imaging, in a selected group of patients.

Design  Prospective study.

Setting  Five fetal maternal tertiary referral centres and an academic radiology unit.

Sample  One hundred cases of fetuses with central nervous system abnormalities where there has been diagnostic difficulties on ultrasound. In 48 cases the women were less than 24 weeks of gestation and in 52 cases later in pregnancy.

Methods  All women were imaged on a 1.5 T clinical system using a single shot fast spin echo technique. The results of antenatal ultrasound and in utero magnetic rosenance were compared.

Main outcome measures  The definitive diagnosis was made either at autopsy or by postmortem magnetic resonance imaging, in cases that went to termination of pregnancy, or a combination of postnatal imaging and clinical follow up in the others.

Results  In 52 of cases, ultrasound and magnetic resonance gave identical results and in a further 12, magnetic resonance provided extra information that was judged not to have had direct effects on management. In 35 of cases, magnetic resonance either changed the diagnosis (29) or gave extra information that could have altered management (6). In 11 of the 30 cases where magnetic resonance changed the diagnosis, the brain was described as normal on magnetic resonance.

Conclusions  In utero magnetic resonance imaging is a powerful tool in investigating fetal brain abnormalities. Our results suggest that in selected cases of brain abnormalitites, detected by ultrasound, antenatal magnetic resonance may provide additional, clinically useful information that may alter management.
Home‐based care after a shortened hospital stay versus hospital‐based care postpartum: an economic evaluation
Authors: Petrou Stavros , Boulvain Michel , Simon Judit , Maricot Patrice , Borst François , Perneger Thomas , Irion Olivier
Published: July 2004

Objectives  To compare the cost effectiveness of early postnatal discharge and home midwifery support with a traditional postnatal hospital stay.

Design  Cost minimisation analysis within a pragmatic randomised controlled trial.

Setting  The University Hospital of Geneva and its catchment area.

Population  Four hundred and fifty‐nine deliveries of a single infant at term following an uncomplicated pregnancy.

Methods  Prospective economic evaluation alongside a randomised controlled trial in which women were allocated to either early postnatal discharge combined with home midwifery support (n= 228) or a traditional postnatal hospital stay (n= 231).

Main outcome measures  Costs (Swiss francs, 2000 prices) to the health service, social services, patients, carers and society accrued between delivery and 28 days postpartum.

Results  Clinical and psychosocial outcomes were similar in the two trial arms. Early postnatal discharge combined with home midwifery support resulted in a significant reduction in postnatal hospital care costs (bootstrap mean difference 1524 francs, 95% confidence interval [CI] 675 to 2403) and a significant increase in community care costs (bootstrap mean difference 295 francs, 95% CI 245 to 343). There were no significant differences in average hospital readmission, hospital outpatient care, direct non‐medical and indirect costs between the two trial groups. Overall, early postnatal discharge combined with home midwifery support resulted in a significant cost saving of 1221 francs per mother–infant dyad (bootstrap mean difference 1209 francs, 95% CI 202 to 2155). This finding remained relatively robust following variations in the values of key economic parameters performed as part of a comprehensive sensitivity analysis.

Conclusions  A policy of early postnatal discharge combined with home midwifery support exhibits weak economic dominance over traditional postnatal care, that is, it significantly reduces costs without compromising the health and wellbeing of the mother and infant.
Women's experiences of student presence in consultations for problematic uterine bleeding
Authors: Guise Jennifer , Willock Joyce , Warner Pam , Calder Andrew , Critchley Hilary
Published: July 2004

Research suggests that although a high proportion of patients accept the presence of students in gynaecological consultations, issues of consent, privacy and comfort are important. This study considers women's views on the impact of student presence on communication in the consultation. Our research suggests that student presence may distort the flow of communication in the gynaecological consultation. There are implications for both patient satisfaction and clinician training. If students are introduced into the consultation, clinical tutors should take special care to maintain dedicated communication with the patient.
Women and health care professionals' preferences for Down's Syndrome screening tests: a conjoint analysis study
Authors: Bishop Amanda J. , Marteau Theresa M. , Armstrong David , Chitty Lyn S. , Longworth Louise , Buxton Martin J. , Berlin Cheryl
Published: July 2004

Objective  To describe and compare women and health care professionals' preferences for Down's Syndrome screening tests with different test characteristics.

Design  Cross sectional questionnaire based conjoint analysis study.

Setting  London teaching hospital.

Sample  291/383 women in their first or second trimester of pregnancy and 98/122 health care professionals (41 obstetricians, senior house officers and above and 57 qualified midwives) providing care at the same hospital.

Methods  Women completed a questionnaire while attending a clinic visit for a dating scan or a routine 20‐week anomaly scan. Health care professionals completed a postal questionnaire.

Main outcome measures  The relative values participants attach to Down's Syndrome screening test attributes: time of test, detection rate and risk of miscarriage of a baby unaffected by Down's Syndrome as a result of subsequent diagnostic tests.

Results  Pregnant women and health care professionals shared broadly similar relative values regarding the importance of safe tests, conducted early and with high detection rates. When asked to choose between different Down's Syndrome screening tests, health care professionals valued earlier tests more highly than did women.

Conclusions  While pregnant women and health care professionals share similar relative values regarding optimal prenatal tests, health care professionals place a higher value on earlier tests. This may result in screening policies that overweight timing in the selection of a test to the relative neglect of tests associated with lower miscarriage rates and higher detection rates but conducted later in pregnancy.
A case‐controlled study comparing clinical course and outcomes of pregnant and non‐pregnant women with severe acute respiratory syndrome
Authors: Lam Chui Miu , Wong Shell Fean , Leung Tse Ngong , Chow Kam Ming , Yu Wai Cho , Wong Tin Yau , Lai Sik To , Ho Lau Cheung
Published: July 2004

Objective  To compare the clinical courses and outcomes of pregnant severe acute respiratory syndrome (SARS) patients and non‐pregnant SARS patients.

Design  A case–control study.

Setting  Tertiary Hospital for Infectious Disease.

Sample  Ten pregnant and 40 non‐pregnant female patients infected with SARS.

Methods  Clinical course and outcomes of pregnant SARS patients were compared with a group of non‐pregnant SARS patient. Cases and controls were matched with respect to sex, age, timing of contracting SARS, health care workers status and underlying illness.

Main outcome measures  The incidence of intensive care unit admission, intubation, medical complications and death rate.

Results  Pregnancy had no discernible impact on clinical symptoms and presentation delay. Four out of the 10 pregnant patients, nevertheless, required endotracheal intubation and six were admitted to the intensive care unit (ICU), as compared with 12.5% intubation rate (P= 0.065) and 17.5% ICU admission rate (P= 0.012) in the non‐pregnant group. More pregnant SARS patients developed renal failure (P= 0.006) and disseminated intravascular coagulopathy (P= 0.006), as compared with non‐pregnant SARS group. There were three deaths in the pregnant group, whereas there was no death in the non‐pregnant control group (P= 0.006).

Conclusion  Pregnant women with SARS experience a worse clinical course and poorer outcomes compared with non‐pregnant women.
Arterial embolisation for persistent primary postpartum haemorrhage: before or after hysterectomy?
Authors: Bloom Allan I. , Verstandig Anthony , Gielchinsky Yuval , Nadiari Michel , Elchalal Uri
Published: July 2004

Arterial embolisation is a recognised treatment for postpartum haemorrhage (PPH). In this retrospective study, we evaluate its use in the management of persistent PPH. Records of all births during a 54 month period at a university hospital were analysed. Two sub‐groups were identified. Group I (n= 5), underwent embolisation after hysterectomy and Group II (n= 4), had embolisation as a first‐line theraphy without hysterectomy. Of 20,215 births, there were 636 cases of PPH (3.1%). Nine required embolisation to control bleeding (1.4%). Group I needed multiple surgical procedures, had a larger pre‐ and post‐operative blood requirement (12–100, median 22 units, vs. 6–12, median 8.5 units), longer embolisation (33–93, median 54 minutes, vs 20–66, 47 minutes) with a larger radiation exposure (5194–9067, median 6301 dGy, vs. 269–3862, median 950 dGy), a longer intensive care stay (3–7, median four days vs. 0–1.5, median one day), and more complications, when compared with Group II. Three of four women from Group II resumed menstrual function. Embolisation prior to hysterectomy may be preferable to embolisation after hysterectomy for the control of PPH.
Comparison of HPV test versus conventional and automation‐assisted Pap screening as potential screening tools for preventing cervical cancer
Authors: Nieminen Pekka , Vuorma Sirkku , Viikki Merja , Hakama Matti , Anttila Ahti
Published: July 2004

Objective  To evaluate new techniques in primary cervical cancer screening programmes.

Design  Cross sectional pilot study.

Setting  Department of Obstetrics and Gynaecology, Helsinki University Hospital.

Population  Consecutive 2032 human papillomavirus (HPV) DNA and Pap smear samples were taken. Histological diagnoses were obtained from 460 patients.

Methods  We compared the validity of the high risk (HR) HPV DNA detection test to automation‐assisted and conventional Pap smear screening.

Main outcome measures  Specificity and sensitivity of screening methods.

Results  Twenty‐three percent of women were HPV positive. Forty‐five of 46 had high grade lesions and cancers were HR HPV DNA positive, whereas 72/93 of low grade and more severe lesions were HR HPV DNA positive. When histologically verified high grade lesions were observed, the relative sensitivity of HR Hybrid Capture 2 (HR HC2) test was 98% compared with conventional Pap smear and Papnet tests, which performed 54%versus 58%, 83%versus 86% and 93%versus 98% relative sensitivity respectively, using cytological diagnoses HSIL (high grade squamous intraepithelial lesion), LSIL (low grade squamous intraepithelial lesion) or ASCUS (atypical squamous cells of undetermined significance) as the cutoff. The specificity of HC2 test (77–79%) was comparable with the ASCUS+ (ASCUS and more severe) cytology (68–79%), but lower when compared with LSIL+ (91–95%) or especially HSIL+ (97–99%) Pap smear results.

Conclusion  Pap smear, as a screening test, is very different from HPV DNA detecting test HR HC 2. If cutoff LSIL or more severe lesions is used, primary Pap smear is clearly more specific than HR HC2, but markedly less sensitive. Due to high relative sensitivity of the HPV, only very few histologically confirmed high grade lesions would be detected among HPV negatives using simultaneous cytology. On the other hand, using HPV DNA test alone would lead to multifold amounts of referrals for colposcopy. A posterior Pap smear assessment among HPV positives might be helpful in increasing sensitivity and specificity of screening and defining those who need an immediate referral or treatment. We plan to incorporate primary HR HPV DNA test with posterior Pap smear reading of HPV positives into our ongoing randomised prospective multiarm trial evaluating new techniques in organised screening for cervical cancer in Finland.
The impact of guidelines on mild hypertension in pregnancy: time series analysis
Authors: Foy Robbie , Ramsay Craig R. , Grimshaw Jeremy M. , Penney Gillian C. , Vale Luke , Thomson Andrew , Greer Ian A.
Published: July 2004

Objective  To determine the impact of a national strategy to promote implementation of a guideline on the management of mild, non‐proteinuric hypertension in pregnancy.

Design  Simple, interrupted time series analysis.

Setting  Four maternity units in Scotland.

Population  Women delivering a live or stillborn baby.

Methods  Dissemination of the guideline under the auspices of a national clinical effectiveness programme, supported by a national launch meeting and feedback from a survey of obstetricians highlighting aspects of care that could be improved.

Main outcome measures  Appropriateness of initial investigation and subsequent clinical management, and costs of guideline development and implementation activities.

Data collection  Twenty‐four months pre‐intervention and 12 months post‐intervention data were abstracted from a random sample of case notes.

Results  Initial investigation was consistent with recommendations for 59.9% out of 1263 women and subsequent clinical management for 67.6% out of 1081 in whom a diagnosis could be made from available data. There were no significant changes in the appropriateness of initial investigation (10.6%; 95% confidence interval [CI] −0.1% to 19.3%; decreasing by 1.2% per month post‐implementation, 95% CI −2.5% to 0.1%) or clinical management (−0.3%; 95% CI −8.7% to 11.2%). Guideline development and implementation cost an estimated £2784 per maternity unit in Scotland.

Conclusions  Clinical care of mild hypertension in pregnancy remains highly inconsistent. The lack of the intervention effect may be related to the complexity of the guideline recommendations and the nature of the implementation strategy.
Home‐based versus hospital‐based postnatal care: a randomised trial
Authors: Boulvain Michel , Perneger Thomas V. , Othenin‐Girard Véronique , Petrou Stavros , Berner Michel , Irion Olivier
Published: July 2004

Objective  To compare a shortened hospital stay with midwife visits at home to usual hospital care after delivery.

Design  Randomised controlled trial.

Setting  Maternity unit of a Swiss teaching hospital.

Population  Four hundred and fifty‐nine women with a single uncomplicated pregnancy at low risk of caesarean section.

Methods  Women were randomised to either home‐based (n= 228) or hospital‐based postnatal care (n= 231). Home‐based postnatal care consisted of early discharge from hospital (24 to 48 hours after delivery) and home visits by a midwife; women in the hospital‐based care group were hospitalised for four to five days.

Main outcome measures  Breastfeeding 28 days postpartum, women's views of their care and readmission to hospital.

Results  Women in the home‐based care group had shorter hospital stays (65 vs 106 hours, P < 0.001) and more midwife visits (4.8 vs 1.7, P < 0.001) than women in the hospital‐based care group. Prevalence of breastfeeding at 28 days was similar between the groups (90%vs 87%, P= 0.30), but women in the home‐based care group reported fewer problems with breastfeeding and greater satisfaction with the help received. There were no differences in satisfaction with care, women's hospital readmissions, postnatal depression scores and health status scores. A higher percentage of neonates in the home‐based care group were readmitted to hospital during the first six months (12%vs 4.8%, P= 0.004).

Conclusions  In low risk pregnancies, early discharge from hospital and midwife visits at home after delivery is an acceptable alternative to a longer duration of care in hospital. Mothers' preferences and economic considerations should be taken into account when choosing a policy of postnatal care.
Premature death among teenage mothers
Authors: Otterblad Olausson Petra , Haglund Bengt , Ringbäck Weitoft Gunilla , Cnattingius Sven
Published: July 2004

Objective  Some data suggest an association between teenage childbearing and premature death. Whether this possible increase in risk is associated with social circumstances before or after childbirth is not known. We studied premature death in relation to age at first birth, social background and social situation after first birth.

Design  Population‐based cohort study.

Setting  Women born in Sweden registered in the 1985 Swedish Population Census.

Population  Swedish women born 1950–1964 who had their first infant before the age of 30 years (N= 460,434).

Methods  Information on the women's social background and social situation after first birth was obtained from Population Censuses. The women were followed up with regard to cause of death from December 1, 1990 to December 31, 1995. Mortality rate ratios and 95% confidence intervals (CI) were calculated.

Main outcome measures  Mortality rates by cause of death.

Results  Independent of socio‐economic background, teenage mothers faced an increased risk of premature death later in life compared with older mothers (rate ratio 1.6, 95% CI 1.4–1.9). The increased risk was most evident for deaths from cervical cancer, lung cancer, ischaemic heart disease, suicide, inflicted violence and alcohol‐related diseases. Some, but not all, of these increases in risk were associated with the poorer social position of teenagers mothers.

Conclusions  Teenage mothers, independent of socio‐economic background, face an increased risk of premature death. Strategies to reduce teenage childbearing are likely to contribute to improved maternal and infant health.
Specific localization of the annexin II heterotetramer in brain lipid raft fractions and its changes in spatial learning
Authors: Zhao Wei‐Qin , Waisman David M. , Grimaldi Maurizio
Published: July 2004

Annexin‐II (AII) is a Ca2+‐dependent phospholipid‐binding protein that is present in both intracellular and extracellular compartments. In the present study AII immunoreactivity was found in a subpopulation of neurons in specific brain regions, including the cerebral cortex and the surface of hippocampal pyramidal neurons from adult rats. AII from synaptic membranes was detected by immunoblotting as multiple species containing the monomer (AII36) and heterotetramer (AIIt). AIIt was resistant to β‐mercaptoethanol and dithiothreitol in sodium dodecyl sulfate–polyacrylamide gel electrophoresis, but was completely reduced to monomers (36 kDa) by two‐dimensional electrophoresis. AIIt resided exclusively in the detergent‐resistant lipid rafts concentrated in neuronal dendrites, and its recruitment to those structures was enhanced by antibody cross‐link. AII abundantly distributed on the outer leaflet of neuronal membranes and between spaces of neurons appeared to be neuronal adhesive. The formation of AIIt required synthesis of sphingolipids and cholesterol, and its stability depended on Ca2+. Increases in neuronal activities such as depolarization and learning were shown to promote formation of AIIt. Our results suggest that, via a dynamic association with dendritic lipid rafts, AII may play a role in synaptic signal transduction and remodeling. This probably involves focal adhesion and interactions with actin that are associated with brain development and memory consolidation.
Molecular genetic responses to lysergic acid diethylamide include transcriptional activation of MAP kinase phosphatase‐1, C/EBP‐β and ILAD‐1, a novel gene with homology to arrestins
Authors: Nichols Charles D. , Sanders‐Bush Elaine
Published: July 2004

We recently demonstrated that the potent hallucinogenic drug lysergic acid diethylamide (LSD) dynamically influences the expression of a small collection of genes within the mammalian prefrontal cortex. Towards generating a greater understanding of the molecular genetic effects of hallucinogens and how they may relate to alterations in behavior, we have identified and characterized expression patterns of a new collection of three genes increased in expression by acute LSD administration. These genes were identified through additional screens of Affymetrix DNA microarrays and examined in experiments to assess dose–response, time course and the receptor mediating the expression changes. The first induced gene, C/EBP‐β, is a transcription factor. The second gene, MKP‐1, suggests that LSD activates the MAP (mitogen activated protein) kinase pathway. The third gene, ILAD‐1, demonstrates sequence similarity to the arrestins. The increase in expression of each gene was partially mediated through LSD interactions at 5‐HT2A (serotonin) receptors. There is evidence of alternative splicing at the ILAD‐1 locus. Furthermore, data suggests that various splice isoforms of ILAD‐1 respond differently at the transcriptional level to LSD. The genes thus far found to be responsive to LSD are beginning to give a more complete picture of the complex intracellular events initiated by hallucinogens.
Relationships between superoxide levels and delayed calcium deregulation in cultured cerebellar granule cells exposed continuously to glutamate
Authors: Vesce Sabino , Kirk Liana , Nicholls David G.
Published: July 2004

The relationship is investigated between superoxide levels in single cultured rat cerebellar granule neurons exposed continuously to glutamate in low KCl medium and the deregulation of cytoplasmic Ca2+. Cells that maintain a regulated cytoplasmic‐free Ca2+ and mitochondrial polarization in the presence of glutamate show no increase in superoxide levels until the onset of cytoplasmic Ca2+ deregulation. Oxidative stress of mitochondrial origin is readily detectable, as the inhibitors rotenone and antimycin A markedly increase superoxide levels with no effect on cytoplasmic‐free Ca2+. The potent cell‐permeant superoxide dismutase/catalase mimetic manganese tetrakis (N‐ethylpyridinium‐2yl) porphyrin, MnTE‐PyP, abolishes the deregulation‐related increase in superoxide but has no effect on deregulation itself. A combination of catalase with the free radical scavenger 4‐hydroxy‐TEMPO also fails to reduce deregulation. Following the loss of Ca2+ homeostasis nuclei undergo condensation; this morphological change is not inhibited by MnTE‐PyP and cannot account for the increased ethidium fluorescence. Phospholipase A2 inhibitors decrease the deregulation‐related increase in superoxide without protecting against deregulation. In conclusion, our study indicates that deregulation is not caused by NMDA receptor‐mediated oxidative stress as NMDA receptor activation does not increase superoxide levels until the onset of deregulation. Furthermore, the majority of superoxide is produced in the cytoplasm rather than in mitochondria.
Increased dopamine release in vivo by estradiol benzoate from the central amygdaloid nucleus of Parkinson's disease model rats
Authors: Liu Bin , Xie Junxia
Published: July 2004

In addition to the dopaminergic neurons in the nigrostriatal system, the properties of dopaminergic neurons in the mesolimbic system, such as the amygdala, are also of interest and importance because of their specific neuromodulatory effects in the pathophysiology of Parkinson's disease (PD). Using the fast cyclic voltammetry (FCV) technique, we present evidence to indicate that electrically‐evoked dopamine (DA) release from the amygdala, especially the central amygdaloid nucleus (CAN), of ovariectomized (OVX) female rats was significantly enhanced with increasing doses of estradiol benzoate (EB; 30, 50 and 100 µg/kg). Impaired DA release from the amygdala of an OVX rat PD model can also be increased by EB treatment (50 µg/kg) to a level similar to that of controls. The well established neuroprotective effects of estrogen may be beneficial for reducing the dysfunction of dopaminergic neurons in mesolimbic structures of rat PD models and PD patients.
Examination of the rate of peptide biosynthesis in neuroendocrine cell lines using a stable isotopic label and mass spectrometry
Authors: Che Fa‐Yun , Yuan Quan , Kalinina Elena , Fricker Lloyd D.
Published: July 2004

The biosynthesis of neuroendocrine peptides is typically examined by following the rate of appearance of a radioactive amino acid into mature forms of peptides. In the present study, we labeled cell lines with l‐leucine containing 10 deuterium residues (d10‐Leu) and used mass spectrometry to measure the biosynthetic rate of γ‐lipotropin in the AtT‐20 cell line and insulin in the INS‐1 cell line. After 3 h of labeling, both peptides show detectable levels of the d‐labeled form in the cells and media. The relative levels of the d‐labeled forms are greater in the media than in the cells, consistent with previous studies that found that newly synthesized peptides are secreted at a higher rate than older peptides under basal conditions. When AtT‐20 cells were stimulated with KCl or forskolin, the ratio of d‐ to H‐labeled γ‐lipotropin in the medium decreased, suggesting that the older peptide was in a compartment that could be released upon the appropriate stimulation. Overexpression of proSAAS in AtT‐20 cells reduced the ratio of d‐ to H‐labeled γ‐lipotropin, consistent with the proposed role of proSAAS as an endogenous inhibitor of prohormone convertase‐1. Labeling with d10‐Leu was also used to test whether altering the pH of the secretory pathway with chloroquine affected the rate of peptide biosynthesis. In AtT‐20 cells, 30 µm chloroquine for 3 or 6 h significantly reduced the rate of formation of γ‐lipotropin in both cells and media. Similarly, INS‐1 cells treated with 10, 30, or 60 µm chloroquine for 6 h showed a significant decrease in the rate of formation of insulin in both cells and media. These results are consistent with the acidic pH optima for peptide processing enzymes. Stable isotopic labeling with d10‐Leu provides a sensitive method to examine the rate of peptide formation in neuroendocrine cell lines.
The c‐Raf inhibitor GW5074 provides neuroprotection in vitro and in an animal model of neurodegeneration through a MEK‐ERK and Akt‐independent mechanism
Authors: Chin Paul C. , Liu Li , Morrison Bradley E. , Siddiq Ambreena , Ratan Rajiv R. , Bottiglieri Teodoro , D'Mello Santosh R.
Published: July 2004

Cerebellar granule neurons undergo apoptosis when switched from a medium containing high potassium (HK) to one that has low potassium (LK). LK‐induced cell death is blocked by GW5074 {5‐Iodo‐3‐[(3,5‐dibromo‐4‐hydroxyphenyl) methylene]‐2‐indolinone}, a synthetic drug that inhibits c‐Raf activity in vitro. GW5074 has no direct effect on the activities of several apoptosis‐associated kinases when assayed in vitro. In contrast to its effect in vitro, treatment of neurons with GW5074 causes c‐Raf activation (when measured in vitro in the absence of the drug) and stimulates the Raf‐MEK‐ERK pathway. Treatment of neurons with GW5074 also leads to an increase in the activity of B‐Raf, which is not inhibited by GW5074 in vitro at concentrations at which the drug exerts its neuroprotective effect. PD98059 and U0126, two distinct inhibitors of MEK, block the activation of ERK by GW5074 but have no effect on its ability to prevent cell death. Overexpression of a dominant‐negative form of Akt does not reduce the efficacy of GW5074, demonstrating an Akt‐independent mechanism of action. Neuroprotection is inhibited by SN‐50, a specific inhibitor of nuclear factor‐kappa B (NF‐κB) and by the Ras inhibitor S‐trans, trans‐farnesylthiosalicylic acid (FTS) implicating NF‐κB and Ras in the neuroprotective signaling pathway activated by GW5074. In addition to preventing LK‐induced apoptosis, treatment with GW5074 protects against the neurotoxic effects of MPP+ and methylmercury in cerebellar granule neurons, and glutathione depletion‐induced oxidative stress in cortical neurons. Furthermore, GW5074 prevents neurodegeneration and improves behavioral outcome in an animal model of Huntington's disease. Given its neuroprotective effect on distinct types of cultured neurons, in response to different neurotoxic stimuli, and in an animal model of neurodegeneration, GW5074 could have therapeutic value against neurodegenerative pathologies in humans.
The tyrosine kinase inhibitor AG126 restores receptor signaling and blocks release functions in activated microglia (brain macrophages) by preventing a chronic rise in the intracellular calcium level
Authors: Kann Oliver , Hoffmann Anja , Schumann Ralf R. , Weber Joerg R. , Kettenmann Helmut , Hanisch Uwe‐Karsten
Published: July 2004

We recently reported that lasting activation of mouse microglial cells with bacterial lipopolysaccharide (LPS) chronically elevated the basal intracellular calcium concentration ([Ca2+]i). This correlated to an attenuated calcium signaling of complement (C5a) and purinergic (UTP) receptors as well as to the capacity for effective production of cytokines–chemokines. Here, we demonstrate that these adjustments in the [Ca2+]i regulation require a critical protein tyrosine kinase (PTK) function – even in varying stimulation scenarios. Changes in basal [Ca2+]i and calcium signaling are not restricted to Gram‐negative bacterial confrontation. Pneumococcal cell wall (PCW) modelling Gram‐positive infection causes virtually the same effects. Moreover, decreases in calcium signaling efficacy are neither associated with altered receptor expression, nor mediated by autocrine loops. Administration of microglial release products, transfer of conditioned supernatant or presence of a radical scavenger during LPS or PCW treatments have no consequence. However, both the elevation in basal [Ca2+]i as well as the suppression of C5a‐ and UTP‐evoked calcium signals are selectively and dose‐dependently reversed by tyrphostin AG126, a PTK inhibitor that, moreover, blocks inducible nitric oxide and cytokine–chemokine release. The findings suggest that the AG126‐sensitive PTK critically controls both sensory and executive features of the microglial activation process via sustained up‐regulation of basal [Ca2+]i.
Arachidonic acid increases choline acetyltransferase activity in spinal cord neurons through a protein kinase C‐mediated mechanism
Authors: Chalimoniuk Malgorzata , King‐Pospisil Kelley , Pedersen Ward A. , Malecki Andrzej , Wylegala Edward , Mattson Mark P. , Hennig Bernhard , Toborek Michal
Published: July 2004

Arachidonic acid (AA) plays an important role as a signaling factor in the CNS. Therefore, exposure to AA may affect cholinergic neurons in the spinal cord. To test this hypothesis, mRNA expression and activity of choline acetyltransferase (ChAT) was measured in cultured spinal cord neurons treated with increasing concentrations (0.1–10 µm) of AA. Exposure to AA increased mRNA levels and activity of ChAT in dose‐ and time‐dependent manners. The most marked effect of AA on ChAT expression was observed in spinal cord neurons treated with 10 µm AA for 1 h. To study the mechanisms associated with these effects, ChAT mRNA levels and activity were measured in cultured spinal cord neurons exposed to AA and inhibitors of protein kinase C (PKC), such as 1‐(5‐isoquinolinesulfonyl)‐2‐methylpiperazine dichloride (H‐7) and chelerythrine. Inhibition of PKC completely prevented an AA‐induced increase in ChAT expression. In addition, exposure of spinal cord neurons to phorbol‐12‐myristate‐13‐acetate (PMA), an activator of PKC, mimicked AA‐induced stimulation of ChAT activity. The AA‐mediated increase in ChAT mRNA levels and activity was also prevented by treatments with EGTA, indicating the role of calcium metabolism in induction of this enzyme. In contrast, treatments with 7‐nitroindazole (7‐NI, a specific inhibitor of neuronal nitric oxide synthase), sodium vanadate (NaV, a non‐specific inhibitor of phosphatases), and N‐acetyl‐cysteine (NAC, an antioxidant) had no effect on AA‐induced changes in ChAT activity. The protein synthesis inhibitor cycloheximide completely blocked AA‐mediated increase in ChAT activity. These results indicate that the AA‐evoked increase in ChAT activity in spinal cord neurons is mediated by PKC, presumably at the transcriptional level.
Systemic serotonin sulfate in opisthobranch mollusks
Authors: Stuart Jeffrey N. , Ebaugh Jason D. , Copes Ashley L. , Hatcher Nathan G. , Gillette Rhanor , Sweedler Jonathan V.
Published: July 2004

Serotonin (5‐hydroxytryptamine, 5‐HT) is a ubiquitous modulatory neurotransmitter with roles as a neurohormone and neurotransmitter. However, few studies have been performed characterizing this molecule and its related metabolites in circulating fluids. Here, we demonstrate native 5‐HT sulfate, but much lower levels of 5‐HT, in hemolymph of the marine mollusk Pleurobranchaea californica. The metabolite 5‐HT sulfate forms from 5‐HT uptake and metabolism in central ganglia of Aplysia californica and in the visceral nerve and eye of Pleurobranchaea, but not in hemolymph itself. In addition, 5‐hydroxyindole acetic acid (5‐HIAA), while not detected in hemolymph, forms in higher quantities than does 5‐HT sulfate in the eye and visceral nerve, and γ‐glu‐5‐HT is also observed in this area but never in hemolymph. As systemic 5‐HT sulfate appears not to originate from the optic region or from systemic 5‐HT, 5‐HT sulfate likely derives from the nervous system. Circulating 5‐HT sulfate is at least 10‐fold higher during the light portion of a 12 : 12‐h light/dark cycle than during the dark portion (p < 0.0007), but there is no obvious trend for free systemic tryptophan (Trp) (p > 0.3) in Pleurobranchaea. 5‐HT in mollusks is associated with general arousal state; thus, diurnal systemic changes in a 5‐HT catabolite may reflect a regulatory role for indole catabolism in behavioral rhythms.
Induction of secretory phospholipase A2 in reactive astrocytes in response to transient focal cerebral ischemia in the rat brain
Authors: Lin Teng‐Nan , Wang Qun , Simonyi Agnes , Chen Jean‐Ju , Cheung Wai‐Mui , Y. He Yong , Xu Jan , Sun Albert Y. , Hsu Chung Y. , Sun Grace Y.
Published: July 2004

Although mRNA expression of group IIA secretory phospholipase A2 (sPLA2‐IIA) has been implicated in responses to injury in the CNS, information on protein expression remains unclear. In this study, we investigated temporal and spatial expression of sPLA2‐IIA mRNA and immunoreactivity in transient focal cerebral ischemia induced in rats by occlusion of the middle cerebral artery. Northern blot analysis showed a biphasic increase in sPLA2‐IIA mRNA expression following 60‐min of ischemia–reperfusion: an early phase at 30 min and a second increase at a late phase ranging from 12 h to 14 days. In situ hybridization localized the early‐phase increase in sPLA2‐IIA mRNA to the affected ischemic cortex and the late‐phase increase to the penumbral area. Besides sPLA2‐IIA mRNA, glial fibrillary acidic protein (GFAP) and cyclo‐oxygenase‐2 mRNAs, but not cytosolic PLA2, also showed an increase in the penumbral area at 3 days after ischemia–reperfusion. Immunohistochemistry of sPLA2‐IIA indicated positive cells in the penumbral area similar to the GFAP‐positive astrocytes but different from the isolectin B4‐positive microglial cells. Confocal microscopy further confirmed immunoreactivity of sPLA2‐IIA in reactive astrocytes but not in microglial cells. Taken together, these results demonstrate for the first time an up‐regulation of the inflammatory sPLA2‐IIA in reactive astrocytes in response to cerebral ischemia–reperfusion.
Role of phospholipase D signaling in ethanol‐induced inhibition of carbachol‐stimulated DNA synthesis of 1321N1 astrocytoma cells
Authors: Guizzetti Marina , Thompson Brian D. , Kim Yunie , VanDeMark Kathryn , Costa Lucio G.
Published: July 2004

Inhibition of astrocyte proliferation has been suggested to be an important event in the developmental neurotoxicity associated with ethanol. We have previously shown that the acetylcholine analog carbachol induces astroglial cell proliferation through activation of muscarinic M3 receptors, and that ethanol strongly inhibits this effect by inhibiting activation of protein kinase C (PKC) ζ and its down‐stream effector 70‐kDa ribosomal S6 kinase (p70S6K). In this study, we investigated whether inhibition by ethanol of this signal transduction pathway in 1321N1 human astrocytoma cells may be due, at least in part, to inhibition of the formation of the PKC ζ activator phosphatidic acid (PA), which is formed by hydrolysis of phosphatidylcholine by phospholipase D (PLD). 1‐Butanol, which is a substrate for PLD and inhibits PA formation, inhibited carbachol‐induced cell proliferation and the underlying intracellular signaling, whereas its analog tert‐butanol, which is a poor substrate for PLD, was much less effective. In addition, exogenous PAs were able to increase DNA synthesis and to activate PKC ζ and p70S6K. Furthermore, in carbachol‐stimulated cells, ethanol increased the formation of phosphatidylethanol and inhibited the formation of PA. Taken together, these results indicate that PLD activation plays an important role in carbachol‐induced astroglial cell proliferation by generating the second messenger PA, which activates PKC ζ. Moreover, the effect of ethanol on carbachol‐induced proliferation appears to be mediated, at least in part, by its ability to interact with PLD leading to a decreased synthesis of PA.
Increased cerebral uptake and oxidation of exogenous βHB improves ATP following traumatic brain injury in adult rats
Authors: Prins M. L. , Lee S. M. , Fujima L. S. , Hovda D. A.
Published: July 2004

There is growing evidence of the brain's ability to increase its reliance on alternative metabolic substrates under conditions of energy stress such as starvation, hypoxia and ischemia. We hypothesized that following traumatic brain injury (TBI), which results in immediate changes in energy metabolism, the adult brain increases uptake and oxidation of the alternative substrate β‐hydroxybutyrate (βHB). Arterio‐venous differences were used to determine global cerebral uptake of βHB and production of 14CO2 from [14C]3‐βHB 3 h after controlled cortical impact (CCI) injury. Quantitative bioluminescence was used to assess regional changes in ATP concentration. As expected, adult sham and CCI animals with only endogenously available βHB showed no significant increase in cerebral uptake of βHB or 14CO2 production. Increasing arterial βHB concentrations 2.9‐fold with 3 h of βHB infusion failed to increase cerebral uptake of βHB or 14CO2 production in adult sham animals. Only CCI animals that received a 3‐h βHB infusion showed an 8.5‐fold increase in cerebral uptake of βHB and greater than 10.7‐fold increase in 14CO2 production relative to sham βHB‐infused animals. The TBI‐induced 20% decrease in ipsilateral cortical ATP concentration was alleviated by 3 h of βHB infusion beginning immediately after CCI injury.