bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cannabinoid mechanism in reinstatement of heroin‐seeking after a long period of abstinence in rats
Authors: Fattore L. , Spano M. S. , Cossu G. , Deiana S. , Fratta W. 
Published: December 2004

AbstractBecause opioid and cannabinoid systems have been reported to interact in the modulation of addictive behaviour, this study was aimed at investigating the ability of cannabinoid agents to reinstate or prevent heroin‐seeking behaviour after a prolonged period of extinction. In rats previously trained to self‐administer heroin intravenously, non‐contingent non‐reinforced priming administrations of heroin and cannabinoids were presented after long‐term extinction, and lever pressing following injections was observed. Results showed that: (i) intravenous priming infusions of heroin (0.1 and 0.2 mg/kg) lead to reinstatement of drug‐seeking behaviour; (ii) intraperitoneal priming injections of the central cannabinoid receptor agonists R‐(+)‐(2,3‐dihydro‐5‐methyl‐3‐[(4‐morpholinyl)methyl]pyrol[1,2,3‐de]‐1,4‐benzoxazinyl) (1‐naphthalenyl)methanonemesylate (WIN 55,212‐2, 0.15 and 0.3 mg/kg) and (–)‐cis‐3‐[2‐hydroxy‐4(1,1‐dimethyl‐heptyl)phenyl]‐trans‐4‐(3‐hydroxypropyl) cyclohexanol (CP 55,940, 0.05 and 0.1 mg/kg), but not Δ9‐tetrahydrocannabinol (Δ9‐THC, 0.1–1.0 mg/kg), effectively restored heroin‐seeking behaviour; (iii) intraperitoneal priming injection of the central cannabinoid receptor antagonist N‐(piperidin‐1‐yl)‐5‐(4‐chlorophenyl)‐1‐(2,4‐dichloro‐phenyl)4‐methyl‐1H‐pyrazole‐3‐carboxamide (SR 141716A, 0.3 mg/kg) did not reinstate responding, but (iv) completely prevented heroin‐induced reinstatement of drug‐seeking behaviour. Moreover, heroin‐seeking behaviour was still present for a few days following cannabinoid primings, indicating a long‐lasting effect of cannabinoids on responding for heroin. These findings indicate that relapse to heroin after an extended drug‐free period is triggered by cannabinoid agonists and that SR 141716A prevents drug‐seeking behaviour, suggesting that the use of the cannabinoid antagonist could have some therapeutic benefits in heroin‐induced relapse.
Subtype switching of vesicular glutamate transporters at parallel fibre–Purkinje cell synapses in developing mouse cerebellum
Authors: Miyazaki Taisuke , Fukaya Masahiro , Shimizu Hidemi , Watanabe Masahiko 
Published: December 2004

AbstractTwo subtypes of the vesicular glutamate transporter are expressed differentially in two excitatory afferents synapsing on to Purkinje cells: VGluT1 (BNPI) in axon terminals of cerebellar granule cells (i.e. parallel fibres; PFs) and VGluT2 (DNPI) in those of the inferior olivary neurons (climbing fibres; CFs). In the present study, we examined their expression in the developing mouse cerebellum. By in situ hybridization, the inferior olivary nucleus selectively expressed VGluT2 mRNA through postnatal life. In the cerebellum, both subtypes were transcribed in the external and internal granular layers during the first postnatal week. Thereafter, VGluT1 mRNA showed marked upregulation in the internal granular layer, whereas VGluT2 mRNA disappeared from the external and internal granular layers by the end of the third postnatal week. By immunohistochemistry, CF terminals consistently exhibited VGluT2 immunoreactivity in the postnatal cerebellum. By contrast, in the first 10 days of postnatal life, VGluT2 predominated in PF terminals, despite the transcription of both transporters in developing granule cells. During the second 10 days, VGluT2 in PF terminals was replaced with VGluT1 from deep regions of the molecular layer upwards, correlating with dendritic translocation of CFs. This replacement was accomplished by postnatal day 30. Taking that late‐borne PFs are laid down successively on earlier ones in the molecular layer, the deep‐to‐superficial replacement represents maturation‐linked switching from VGluT2 to VGluT1 in individual PFs, and is likely to be regulated at both the transcription and translation levels.
The immunocytochemical localization of connexin 36 at rod and cone gap junctions in the guinea pig retina
Authors: Lee Eun‐Jin , Han Jung‐Won , Kim Hyun‐Ju , Kim In‐Beom , Lee Mun‐Yong , Oh Su‐Ja , Chung Jin‐Woong , Chun Myung‐Hoon 
Published: December 2004

AbstractConnexin 36 (Cx36) is a channel‐forming protein found in the membranes of apposed cells, forming the hexameric hemichannels of intercellular gap junction channels. It localizes to certain neurons in various regions of the brain including the retina. We characterized the expression pattern of neuronal Cx36 in the guinea pig retina by immunocytochemistry using specific antisera against Cx36 and green/red cone opsin or recoverin. Strong Cx36 immunoreactivity was visible in the ON sublamina of the inner plexiform layer and in the outer plexiform layer, as punctate labelling patterns. Double‐labelling experiments with antibody directed against Cx36 and green/red cone opsin or recoverin showed that strong clustered Cx36 immunoreactivity localized to the axon terminals of cone or close to rod photoreceptors. By electron microscopy, Cx36 immunoreactivity was visible in the gap junctions as well as in the cytoplasmic matrices of both sides of cone photoreceptors. In the gap junctions between cone and rod photoreceptors, Cx36 immunoreactivity was only visible in the cytoplasmic matrices of cone photoreceptors. These results clearly indicate that Cx36 forms homologous gap junctions between neighbouring cone photoreceptors, and forms heterologous gap junctions between cone and rod photoreceptors in guinea pig retina. This focal location of Cx36 at the terminals of the photoreceptor suggests that rod photoreceptors can transmit rod signals to the pedicle of a neighbouring cone photoreceptor via Cx36, and that the cone in turn signals to corresponding ganglion cells via ON and OFF cone bipolar cells.
Mothers reduce egg provisioning with age
Authors: Giron David , Casas Jérôme 
Published: December 2004

AbstractPrecise and comprehensive data on resource allocation into individual eggs are rare and this empirical void in the literature of life history strategies contrasts with the large number of theoretical studies. We show a marked decrease in reproductive investment in eggs with mother's age for egg size, sugar, protein, lipid and energy contents of eggs for a parasitic wasp. Egg size is a good predictor of offspring fitness, measured as survival of starving neonate larvae, but does not reveal possible biochemical changes. Lipids stabilize quickly at a minimal threshold while proteins and sugars decrease smoothly down to about 30% of the amount invested in the first egg. Because proteins have the highest correlation with egg size, we predict that they should be better predictors of larval fitness than lipids and sugars. Assessing the adaptive value of the observed patterns will require a multidimensional approach to egg provisioning.
Allometry of human fertility and energy use
Authors: Moses Melanie E. , Brown James H. 
Published: December 2004

AbstractThe flux of energy and materials constrains all organisms, and allometric relationships between rates of energy consumption and other biological rates are manifest at many levels of biological organization. Although human ecology is unusual in many respects, human populations also face energetic constraints. Here we present a model relating fertility rates to per capita energy consumption rates in contemporary human nations. Fertility declines as energy consumption increases with a scaling exponent of −1/3 as predicted by allometric theory. The decline may be explained by parental trade‐offs between the number of children and the energetic investment in each child. We hypothesize that the −1/3 exponent results from the scaling properties of the networked infrastructure that delivers energy to consumers. This allometric analysis of human fertility offers a framework for understanding the demographic transition to smaller family sizes, with implications for human population growth, resource use and sustainability.
Do rock endemic and widespread plant species differ under the Leaf–Height–Seed plant ecology strategy scheme?
Authors: Lavergne Sébastien , Garnier Eric , Debussche Max 
Published: December 2004

Abstract Westoby (1998) proposed the Leaf–Height–Seed (L–H–S) scheme, i.e. the use of three functional traits, specific leaf area (SLA), plant canopy height and seed mass, to describe plant ecological strategies. In this study, we examine whether endemic species from cliffs and rocky outcrops can be discriminated in a regional Mediterranean flora according to these three traits. First, we conducted a comparison across 13 pairs of rock endemic species and widespread congeners. Second, we performed a canonical discriminant analysis to compare the position in the L–H–S volume of these 13 pairs of endemic and widespread congeners with that of 35 phylogenetically unrelated widespread species taken from the same regional flora. Our results show that rock endemic species only differ from their widespread congeners in their smaller stature. However, when compared with the 35 unrelated widespread species, endemic species are discriminated by higher SLA and taller stature, and thus are not close to the stress‐tolerant pole of ecological strategies (small stature, low SLA), as hypothesized in the literature.
Contribution of rarity and commonness to patterns of species richness
Authors: Lennon Jack J. , Koleff Patricia , Greenwood Jeremy J. D. , Gaston Kevin J. 
Published: December 2004

AbstractThere is little understanding in ecology as to how biodiversity patterns emerge from the distribution patterns of individual species. Here we consider the question of the contributions of rare (restricted range) and common (widespread) species to richness patterns. Considering a species richness pattern, is most of the spatial structure, in terms of where the peaks and troughs of diversity lie, caused by the common species or the rare species (or neither)? Using southern African and British bird richness patterns, we show here that commoner species are most responsible for richness patterns. While rare and common species show markedly different species richness patterns, most spatial patterning in richness is caused by relatively few, more common, species. The level of redundancy we found suggests that a broad understanding of what determines the majority of spatial variation in biodiversity may be had by considering only a minority of species.
Evidence for transmission between humans and the environment of a nosocomial strain of Enterococcus faecium
Authors: Iversen Aina , Kühn Inger , Rahman Mokhlasur , Franklin Anders , Burman Lars G. , Olsson‐Liljequist Barbro , Torell Erik , Möllby Roland 
Published: December 2004

SummaryAn ampicillin‐ and ciprofloxacin‐resistant Enterococcus faecium (ARE) strain, named FMSE1, with a characteristic biochemical phenotype, was in a recent study found to dominate among faecal ARE isolates from patients in several Swedish hospitals. In the present study, the prevalence of this strain among 9676 enterococcal isolates from healthy children, hospital sewage, urban sewage, surface water, slaughtered animals (broilers, pigs and cattle) and pig faeces and manure was investigated. Enterococcal isolates having the same biochemical phenotype as the FMSE1 were most common in samples of hospital sewage (50%), surface water (35%), treated sewage (28%) and untreated sewage (17%), but rare in samples from healthy children (0.8%) and animals (2%). PFGE typing of FMSE1‐like isolates from hospital sewage indicated that they were closely related to the nosocomial FMSE1 strain. Thus, this study indicated a possible transmission route for nosocomial E. faecium from patients in hospitals to hospital sewage and urban sewage, and further via treatment plants to surface water and possibly back to humans. This proposed route of circulation of drug‐resistant enterococci might be further amplified by antibiotic usage in human medicine. In contrast, such transmission from food animals seems to play a negligible role in Sweden.
In vivo functional genomics of Pseudomonas aeruginosa for high‐throughput screening of new virulence factors and antibacterial targets
Authors: Potvin Eric , Lehoux Dario E. , Kukavica‐Ibrulj Irena , Richard Karine L. , Sanschagrin François , Lau Gee W. , Levesque Roger C. 
Published: December 2004

Summary Pseudomonas aeruginosa is a model for studying opportunistic pathogens that are highly resistant to most classes of antibiotics and cause chronic pulmonary infections. We have developed and adapted a multiplex polymerase chain reaction‐based signature‐tagged mutagenesis (STM) for high‐throughput screening of a collection of 7968 P. aeruginosa mutants in a rat model of chronic respiratory infection. After three rounds of screening, a total of 214 mutants, representing transposition events into 148 open reading frames, were shown to be attenuated in lung infection and were retained for further analysis. As proof of concept supporting this technology, we identified 11 insertions in typical virulence genes such as those coding for pili implicated in motility, attachment and swarming, alginate synthesis and its expression, a mucus transcription regulator, extracellular enzymes such as alkaline protease, esterase and amino peptidase, a rhamnosyl surfactant transferase and a lipopolysaccharide glycosyl transferase. Detailed analysis of the 148 STM mutants, including seven auxotrophs, revealed insertions in 21 of the 26 known gene classes used to characterize sequenced bacterial genomes. We noted that at least 46% of STM mutants identified had insertions in hypothetical proteins or proteins of unknown function and that ≈ 40% of all STM mutants had insertions in surface proteins including the outer membrane, the periplasm and the inner membrane. Interestingly, 11 STM mutants attenuated for lung infection were also identified in microarray and transcriptome for quorum sensing and mucoidy production. The remaining 130 mutants were systematically analysed for their capability to express fully known virulence factors. In addition, testing the ability of these mutants to infect alternative model host Drosophila melanogaster revealed 36 STM mutants defective in protease, twitching motility, swimming and swarming. Finally, we identified many genes, the activity of which in respiratory infection was not fully appreciated.
Effect of Cogent db, a herbal drug, on serum and tissue lipid metabolism in experimental hyperglycaemic rats
Authors: Saravanan G. , Pari L. 
Published: December 2004

Aims:  We have previously reported the antidiabetic effect of Cogent db. The present study with alloxan‐induced hyperglycaemic rats is focused on the mechanism of action, specifically on the activity of hepatic lipogenic enzymes, serum and tissue lipids.Methods:  Male Wistar rats body weight of 180–200 g (six normal and 18 diabetic rats) were used in this study. The rats were divided into four groups after the induction of alloxan diabetes: normal rats; diabetic control; diabetic rats given Cogent db (0.45 g/kg body weight); diabetic rats given glibenclamide (600 µg/kg body weight). After 40 days treatment, fasting blood glucose, plasma insulin, activities of hepatic lipogenic enzymes, serum and tissue lipids were determined in normal and experimental animals.Results:  Oral administration of Cogent db for 40 days resulted in significant reduction in blood glucose, serum and tissue (liver and kidney) lipids, whereas the level of plasma insulin and the activity of hepatic lipogenic enzymes were significantly increased in alloxan diabetic rats. Similar studies using glibenclamide have been conducted to compare the mode of action of these two drugs.Conclusions:  Thus our study shows that Cogent db exhibits a strong antihyperlipidaemic effect, which could exert a beneficial action against macrovascular complications (cardiovascular disease) associated with diabetes mellitus.
Gestational diabetes mellitus in the last trimester – a feature of maternal iron excess?
Authors: Lao T. T. , Chan P. L. , Tam K. F. 
Published: December 2004

SUMMARY Aim  To determine whether non‐anaemic women with gestational diabetes mellitus (GDM) diagnosed in third trimester pregnancy have evidence of increased iron stores compared with matched non‐diabetic controls.Methods  In a prospective study, women who had antenatal booking before 20 weeks' gestation and without anaemia or diabetes mellitus were recruited at the time of the oral glucose tolerance test (OGTT) at 28–31 weeks' gestation for the study of serum ferritin, iron and transferrin concentrations. The results were blinded to the managing obstetricians. After delivery, the records were reviewed. The cases diagnosed as GDM were compared with a control group (two controls for each index case matched for parity) selected at random from the at‐risk but nondiabetic cases.Results  GDM was diagnosed in 97 of the 401 women recruited. Compared with the 194 controls, there was no difference in the weight, body mass index, booking and third trimester haemoglobin, or third trimester red cell indices, but concentrations of serum ferritin, iron, transferrin saturation, and the post‐natal haemoglobin were significantly higher. On multiple regression analysis, maternal BMI and the log‐transformed ferritin concentration remained significant determinants of the OGTT 2‐h glucose value.Conclusion  The results suggest an association between increased iron stores and glucose intolerance at the third trimester in non‐anaemic women. The role of iron excess in the pathogenesis of GDM needs to be examined.
Subcutaneous glucose sensor values closely parallel blood glucose during insulin‐induced hypoglycaemia
Authors: Caplin N. J. , O'Leary P. , Bulsara M. , Davis E. A. , Jones T. W. 
Published: December 2004

AbstractAims To assess the accuracy of the Minimed continuous glucose monitoring system (CGMS) in estimating blood glucose concentration during a controlled reduction in blood glucose.Research design and methods We studied nine adolescent diabetics (age 14 ± 1.5 years) wearing the CGMS during hyperinsulinaemic hypoglycaemic clamp studies. The glucose values obtained by the CGMS were compared with the venous blood samples taken during the studies and measured at the bedside using a glucose oxidase technique.Results Blood glucose was lowered from euglycaemia to a mean of 2.8 mmol/l over 120 min and maintained at that level for a further 40 min. A total of 429 paired glucose measurements were available for analysis. Analysis using weighted Deming regression and t‐tests revealed small differences between the methods, with blood glucose levels slightly higher than interstitial fluid levels. The mean difference across all values was 0.13 mmol/l. The observed difference was greatest at blood glucose values < 3.3 mmol/l.Conclusions This study suggests that during a fall in systemic glucose the subcutaneous glucose sensor provides an accurate reflection of blood glucose. However, a small difference is apparent at blood glucose values < 3.3 mmol/l.Diabet. Med. 20, 238–241 (2003)
Autoantibodies to the islet cell antigen SOX‐13 are associated with duration but not type of diabetes
Authors: Davis T. M. E. , Mehta Z. , Mackay I. R. , Cull C. A. , Bruce D. G. , Fida S. , Rowley M. J. , Holman R. R. 
Published: December 2004

AbstractAims The autoantigen SOX‐13 of the SRY‐related high mobility group box is a low‐frequency reactant in sera from patients with Type 1 diabetes. We further investigated the potential diagnostic role of anti‐SOX‐13, and in particular its ability to distinguish Type 1 from Type 2 diabetes, in two large, well‐characterized cohorts.Methods SOX‐13 autoantibody status was ascertained using a radioimmunoprecipitation assay in (i) a random sample of 546 participants in an Australian community‐based study (the Fremantle Diabetes Study; FDS) of whom 119 had Type 1 and 427 Type 2 diabetes, and (ii) a sample of 333 subjects with Type 2 diabetes from the United Kingdom Prospective Diabetes Study (UKPDS) stratified by age, anti‐glutamic acid decarboxylase (GAD) and islet cell antibody (ICA) status, and requirement for insulin therapy within 6 years of diagnosis.Results The frequencies of anti‐SOX‐13 in the FDS subjects were 16.0% and 14.8% for Type 1 and Type 2 patients, respectively, and levels were similar. In the UKPDS subjects, the frequency was 4.5%. In a logistic regression model involving demographic, anthropometric and metabolic variables, only diabetes duration was significantly associated with anti‐SOX‐13 positivity, especially for duration > 5 years (P < 0.002). When the coexistence of autoantibodies was assessed in the two study samples, there were no significant associations between anti‐SOX‐13 and ICA, anti‐GAD or ICA512/IA‐2.Conclusions Whilst the frequency of anti‐SOX‐13 may be increased in some populations of diabetic patients, this reactivity does not usefully distinguish Type 1 from Type 2 diabetes. However, the association with diabetes duration suggests that anti‐SOX‐13 may be a non‐specific marker of tissue damage associated with chronic hyperglycaemia.Diabet. Med. 20, 198–204 (2003)
A repeated cross‐sectional survey of severe hypoglycaemia in 178 Type 1 diabetes mellitus patients performed in 1984 and 1998
Authors: Bragd J. , Adamson U. , Lins P.‐E. , Wredling R. , Oskarsson P. 
Published: December 2004

AbstractAims To study the prevalence of severe hypoglycaemia (SH) in relation to risk factors in Type 1 diabetic (T1 DM) patients over a period of 14 years.Methods We performed a cross‐sectional survey of a cohort of 178 T1 DM patients registered at our out‐patient clinic in 1984 to be repeated in 1998. An identical questionnaire was sent to the patients in the beginning of 1985 and 1999, respectively, regarding the problem of SH in the preceding year. Additional clinical data were obtained from the patients’ medical records on insulin treatment, long‐term complications, morbidity, and co‐medication.Results At follow up, the use of multiple insulin injection therapy had increased from 71% to 98% (P < 0.001) and daily self‐monitoring of blood glucose (SMBG) from 17% to 48% (P < 0.001). Twenty‐seven percent were treated with direct‐acting insulin analogues in 1998. An increasing number of patients reported unawareness of hypoglycaemia, 54% vs. 40% (P < 0.01), and nocturnal events were more frequent, 83% vs. 76% (P < 0.05). The prevalence of SH had increased from 17% to 27% (P < 0.05) and a slight decrease of HbA1c, 7.6% to 7.4% (P < 0.05) was documented.Conclusion We conclude that despite more frequent use of multiple injection therapy and SMBG, the prevalence of SH has increased by > 50% over 14 years. A multiple logistic regression analysis of risk factors for SH explained less than 10% of the variance, implicating only unawareness of hypoglycaemia and HbA1c.Diabet. Med. 20, 216–219 (2003)