bluuebunny/crossref_metadata_2025 huggingface dataset:
Size‐Dependent Male Alternative Reproductive Tactics in the Shell‐Brooding Cichlid Fish Lamprologus callipterus in Lake Tanganyika
Authors: Sato Tetsu , Hirose Mitsuru , Taborsky Michael , Kimura Seishi
Published: December 2004

Reproductive parasitism among males is prevalent in fishes. Typically, small ripe males parasitize the reproductive effort of large bourgeois males by using various behavioural tactics. We examined the size‐dependent advantages of parasitic behavioural tactics in a shell‐brooding cichlid fish of Lake Tanganyika with three male types (large bourgeois males and medium–dwarf parasitic males). The extremely small ‘dwarf males’ weighing only 2.5% on average of large males, perform a specialized tactic in which they avoid attacks by the resident large males by entering the inner part of the whorl of the shell where a female is spawning. Field observations and a manipulation experiment revealed that the very small size of dwarf males is essential for utilizing this positional advantage. Larger dwarf males and medium males opportunistically adopt darting and sneaking which likely result in very low reproductive outcomes. The size associated advantage and disadvantage of parasitic tactics are the major factors shaping the size distribution of ripe males in this species. The success of parasitic spawning by dwarf males is determined not only by body size of the males, but also by the relative sizes of females and shells in which they spawn. These factors would affect the choice of different tactics among dwarf males. The analyses of body condition among ripe and unripe males across a wide range of body sizes suggested that onset of sexual activities at very small body sizes in dwarf males may be associated with higher condition factors that is a pre‐requisite for maintaining investment in testes and intense reproductive activities.
Molecular characterization of a phytoplasma from the aster yellows (16SrI) group naturally infecting Populus nigra L. ‘Italica’ trees in Croatia
Authors: Šeruga M. , Škorić D. , Botti S. , Paltrinieri S. , Juretić N. , Bertaccini A. F.
Published: December 2004

Leaf and branch samples were collected from 10 Populus nigra L. ‘Italica’ trees found in the Zagreb urban area. One of the P. nigra L. ‘Italica’ trees exhibited leaf yellowing, overall sparse foliage, stunting and decline. Two methods for the nucleic acid extraction in the phytoplasma detection from P. nigra were compared. A phytoplasma from the aster yellows group (16SrI) was detected by PCR in the symptomatic as well as in four apparently asymptomatic plants. The pathogens are classified, by restriction fragment length polymorphism (RFLP) analysis of the 16S rRNA gene plus the spacer region, as members of a newly described subgroup 16SrI‐P. Phylogenetic analysis of 16S ribosomal and spacer region sequence confirmed their close relationship with the other members of the aster yellows group. However, RFLP analyses of other conserved genes such as tuf, BB88 and ribosomal protein rpL22 gene, clearly confirmed that this is a molecularly distinguishable phytoplasma belonging to a new ribosomal protein subgroup designated rp‐O.
Keloids – clinical diagnosis, pathogenesis, and treatment options
Authors: Marneros Alexander G. , Krieg Thomas
Published: December 2004

Keloids are defined as excessive scar tissue formation extending beyond the area of the original skin injury and occurring in predisposed individuals. They are considered to be a result of abnormal wound healing. The pathogenetic mechanisms that cause keloids remain unknown. Experiments with cells derived from keloid tissue revealed a number of abnormalities in cellular functions, such as in proliferation, apoptosis, or expression of growth factors and extracellular matrix proteins. Furthermore, several studies have reported altered keratinocyte‐fibroblast interactions in keloids. Despite the diverse pathological changes in cellular functions and expression profiles of cells derived from keloid tissue, recent genetic studies have provided evidence that single genes may act as major regulators of keloid formation. We provide an overview of the pathogenetic mechanisms of keloid formation in the context of their clinical characteristics and current therapeutic approaches.
Determination of the formation of the stratum corneum reservoir for two different corticosteroid formulations using tape stripping combined with UV/VIS spectroscopy
Authors: Pelchrzim Ragna v. , Weigmann Hans‐Jürgen , Schaefer Hans , Hagemeister Timo , Linscheid Michael , Shah Vinod P. , Sterry Wolfram , Lademann Jürgen
Published: December 2004

Background: The stratum corneum, the outermost layer of the skin, not only represents a barrier, but also a reservoir for topically applied substances. Both properties influence the penetration process, as does the vehicle. It determines the penetration pathway and the retention time of the topically applied substances.

Methods: Two commercial products (Temovate Cream and Temovate Emollient), both containing 0.05 % clobetasol propionate, were applied on the inner forearms of healthy volunteers. 20 tape strips were removed from each treated skin area. The horny layer profile was determined measuring the absorption of the corneocytes at 430 nm. The concentration of clobetasol propionate on the individual tapes was then analyzed.

Results: We found differences in the reservoir formation depending on the formulation applied, which correlated to the biological response in the form of a blanching effect.

Conclusions: The method applied is well‐suited to determine the reservoir formation in the stratum corneum for topically applied substances.
Suspected snakebite: One year prospective study of emergency department presentations
Authors: Isbister Geoffrey K , Currie Bart J
Published: December 2004

Aim:  Snakebite is an uncommon, but potentially life‐threatening condition. The more common clinical scenario is suspected snake‐bite. Our aim was to characterise the epidemiology, diagnosis and management of patients with suspected snakebites.

Methods:  Prospective cohort study of patients presenting with suspected snakebites to a tertiary referral hospital serving a large rural region in tropical northern Australia where a standard admission protocol for suspected snakebites is used.

Results:  Of 70 suspected snakebite cases, there were 45 definite bites: three severe envenomings (two western brown snakes [Pseudonaja nuchalis] and one mulga snake [Pseudechis australis]); seven mild/moderate envenomings by other snakes, two non‐envenomings by identified P. nuchalis, five bites by identified non‐venomous snakes and 28 definite bites without envenoming. The remaining 25 cases were either suspected bites (8), unlikely bites (15) and two people hit by snakes. Definite snake‐bites occurred throughout the year, peaking in May and December. There were three severe envenomings (mainly coagulopathy), requiring antivenom treatment, but no deaths or major complications. Most patients had appropriate investigations. Of 47 venom detection kit swabs collected, 34 were not tested, venom was not detected in nine and was positive in the three envenomings with one false‐positive tiger snake. Whole blood clotting time was highly sensitive for procoagulant coagulopathy and envenoming in this study. Median length of time from the bite to discharge was 20 h (interquartile range: 12–27).

Conclusions:  The study shows that although suspected snakebite was common, severe envenoming occurred in less than 5% of cases. The study supports the proposition that a structured approach and admission policy of suspected snakebites leads to the appropriate management of severe envenoming, with no cases discharged early and no cases of non‐envenoming treated with antivenom.
Endoscopic removal of primary B‐cell mucosa‐associated lymphoid tissue lymphoma of the cecum
Authors: KOYAMA NOBUATSU , YAMASHITA NAOYUKI , SAKURAZAWA NOBUYUKI , WACHI EIKO
Published: December 2004

A 61‐year‐old woman with a history of positive fecal occult blood test was referred for further evaluation. She was symptom‐free and had no family history of colorectal cancer. Colonoscopy revealed a semipedunculated polyp with a surface of normal appearance. Although a biopsy specimen revealed inflammatory cells including numerous small lymphocytes in the mucosa, a definitive diagnosis was not made. Four weeks later, endoscopic removal using the submucosal injection method was performed for diagnosis as well as treatment. The tumor measured 14 × 13 × 6 mm. The pathological diagnosis was low‐grade B‐cell mucosa‐associated lymphoid tissue (MALT) lymphoma, and the depth of invasion was estimated as the submucosal layer. The case described here suggests that MALT lymphoma should be added to the differential diagnosis of colorectal submucosal tumors, and some cases of them might be resected endoscopically using the submucosal injection method.
Receptor‐selective changes in µ‐, δ‐ and κ‐opioid receptors after chronic naltrexone treatment in mice
Authors: Lesscher Heidi M. B. , Bailey Alexis , Burbach J. Peter H. , Van Ree Jan M. , Kitchen Ian , Gerrits Mirjam A. F. M.
Published: December 2004

Chronic treatment with the opioid antagonist naltrexone induces functional supersensitivity to opioid agonists, which may be explained by receptor up‐regulation induced by opioid receptor blockade. In the present study, the levels of opioid receptor subtypes through the brain of mice were determined after chronic naltrexone treatment using quantitative in vitro autoradiography. This is the first complete mapping study in mice for µ‐, δ‐ and κ‐opioid receptors after chronic naltrexone exposure. Treatment with naltrexone clearly induced up‐regulation of µ‐ (mean 80%) and, to a lesser extent, δ‐opioid receptors (mean 39%). The up‐regulation of µ‐ and δ‐opioid receptors was evident throughout the brain, although there was variation in the percentage change across brain regions. In contrast, consistent up‐regulation of κ‐opioid receptors was observed in cortical structures only and was not so marked as for µ‐ and δ‐opioid receptors. In noncortical regions κ‐opioid receptor expression was unchanged. Taken together, the present findings suggest opioid receptor subtype‐selective regulation by chronic naltrexone treatment in mice.
Functional properties and interaction of the anterior and posterior intraparietal areas in humans
Authors: Shikata Elisa , Hamzei Farsin , Glauche Volkmar , Koch Martin , Weiller Cornelius , Binkofski Ferdinand , Büchel Christian
Published: December 2004

In the monkey the lateral bank of the anterior part of the intraparietal sulcus (area AIP), contains neurons that are involved in visually guided, object‐related hand movements. It has also been shown that neurons in the caudal part of the intraparietal sulcus (area CIP) preferentially respond to 3D surface orientation. According to these results, it has been hypothesized that neurons in area CIP primarily encode the 3D features of an object and forwards this information to area AIP. AIP then utilizes this information for appropriate hand actions towards the object. Based on analogies to these primate studies, recent neuroimaging studies have suggested human homologues of areas AIP and CIP, however, the functional interaction between these areas remains unclear. Our event related fMRI study was designed to address specifically the question, how CIP and AIP interact in the process of adjustment of hand orientation towards objects. Volunteers were asked to perform three tasks: discrimination of surface orientation, imaging of visually guided hand movements and execution of visually guided hand movements. Our data show that the human AIP was activated both during discrimination of surface orientation and during the subsequent spatial adjustment of the thumb and index finger position towards the surface orientation. In contrast, human CIP was activated by the surface orientation but not by spatial adjustment of finger position. These data clearly indicate that the function of human CIP is more involved in coding 3D features of the objects, whereas human AIP is more involved in visually guided hand movements, similar to its role in the monkey.
A tripartite motif protein TRIM11 binds and destabilizes Humanin, a neuroprotective peptide against Alzheimer's disease‐relevant insults
Authors: Niikura Takako , Hashimoto Yuichi , Tajima Hirohisa , Ishizaka Miho , Yamagishi Yohichi , Kawasumi Masaoki , Nawa Mikiro , Terashita Kenzo , Aiso Sadakazu , Nishimoto Ikuo
Published: December 2004

Humanin (HN) is a newly identified neuroprotective peptide that specifically suppresses Alzheimer's disease (AD)‐related neurotoxicity. HN peptide has been detected in the human AD brain as well as in mouse testis and colon by immunoblot and immunohistochemical analyses. By means of yeast two‐hybrid screening, we identified TRIM11 as a novel HN‐interacting protein. TRIM11, which is a member of protein family containing a tripartite motif (TRIM), is composed of a RING finger domain, which is a putative E3 ubiquitin ligase, a B‐box domain, a coiled‐coil domain and a B30.2 domain. Deletion of the B30.2 domain in TRIM11 abolished the interaction with HN, whereas the B30.2 domain alone did not interact with HN. For their interaction, at least the coiled‐coil domain was indispensable together with the B30.2 domain. The intracellular level of glutathione S‐transferase‐fused or EGFP‐fused HN peptides or plain HN was drastically reduced by the coexpression of TRIM11. Disruption of the RING finger domain by deleting the first consensus cysteine or proteasome inhibitor treatment significantly diminished the effect of TRIM11 on the intracellular level of HN. These results suggest that TRIM11 plays a role in the regulation of intracellular HN level through ubiquitin‐mediated protein degradation pathways.
Computer model of passive signal integration based on whole‐cell in vitro studies of rat lateral geniculate nucleus
Authors: Briska Adam M. , Uhlrich Daniel J. , Lytton William W.
Published: December 2004

Computer models were used to investigate passive properties of lateral geniculate nucleus thalamocortical cells and thalamic interneurons based on in vitro whole‐cell study. Two neurons of each type were characterized physiologically and morphologically. Thalamocortical cells transmitted 37% of steady‐state signal orthodromically (distal dendrite to soma) and 93% antidromically (soma to distal dendrite); interneurons transmitted 18% orthodromically and 53% antidromically. Lowering membrane resistance caused a dramatic drop in steady‐state signal transmission. Simulation of brief signals such as orthodromically transmitted postsynaptic potentials and antidromically transmitted action potentials showed relatively poor transmission due to the low‐pass filtering property of dendrites. This attenuation was particularly pronounced in interneurons. By contrast, bursts of postsynaptic potentials or action potentials were relatively well transmitted as the temporal summation of these recurring signals gave prolonged depolarizations comparable to prolonged current injection. While synaptic clustering, active channels and reduction of membrane resistance by ongoing synaptic activity will have additional profound effects in vivo, the present in vitro modelling suggests that passive signal transmission in neurons will depend on type of signal conveyed, on directionality and on membrane state. This will be particularly important for thalamic interneurons, whose presynaptic dendrites may either work independently or function in concert with each other and with the soma. Our findings suggest that bursts may be particularly well transmitted along dendrites, allowing firing format to alter the functional anatomy of the cell.
Double dissociation of the effects of lesions of basolateral and central amygdala on conditioned stimulus‐potentiated feeding and Pavlovian‐instrumental transfer
Authors: Holland Peter C. , Gallagher Michela
Published: December 2004

Pavlovian conditioned stimuli (CSs) for food can enhance both the performance of instrumental responses that earn food (Pavlovian‐instrumental transfer; PIT) and the consumption of food itself (CS‐potentiated feeding). After a single phase of Pavlovian training, each rat was tested in both PIT and potentiated feeding tasks. Rats with lesions of the central nucleus of the amygdala failed to exhibit PIT but showed normal CS‐potentiated feeding. By contrast, rats with lesions of the basolateral amygdala showed normal PIT but failed to display CS‐potentiated feeding. Performances in a variety of comparison conditions suggested that both lesion effects reflected impairment of acquired motivational functions, rather than with attentional processes or the display of specific learned responses. Implications of the double dissociation of these two aspects of Pavlovian conditioned incentive motivation for amygdala function in associative learning are considered.
Differential behavioural sensitization to intermittent morphine treatment in alcohol‐preferring AA and alcohol‐avoiding ANA rats: role of mesolimbic dopamine
Authors: Ojanen Sami , Koistinen Meri , Bäckström Pia , Kankaanpää Aino , Tuomainen Päivi , Hyytiä Petri , Kiianmaa Kalervo
Published: December 2004

Alcohol‐preferring AA (Alko Alcohol) and alcohol‐avoiding ANA (Alko Non‐Alcohol) rats have well‐documented differences in their voluntary ethanol consumption and brain opioidergic systems. The aim of the present study was to investigate whether these rat lines differ in their susceptibility to morphine‐induced behavioural and neurochemical sensitization. The rats were given 15 injections of morphine (10 mg/kg, s.c.) or saline every other day. Locomotor activity and release of dopamine in the nucleus accumbens were monitored after a challenge with additional morphine injections (10 mg/kg) 1 and 5 weeks after withdrawal from the repeated treatment. Morphine increased locomotion more in the previously morphine‐treated rats than in the saline‐treated controls. Furthermore, AA rats were more sensitive to this effect of morphine than ANA rats. Accumbal morphine‐induced dopamine release was significantly higher in the morphine‐treated AA than ANA rats after the first challenge injection 1 week from withdrawal, but no differences were observed after the second challenge. The brain and plasma concentrations of morphine were similar among the lines suggesting that the differences in the effects of morphine cannot be explained in terms of differential pharmacokinetics of morphine in these lines. These data show that AA rats are more susceptible to morphine‐induced behavioural sensitization than ANA rats. Furthermore, it suggests that mesolimbic dopamine has at best only a transient role in the expression of opioid‐induced behavioural sensitization. The relationship between the mechanisms underlying the differential sensitivity of these rat lines to the effects of repeated morphine and voluntary ethanol drinking remains to be determined.
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

Because 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

Two 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

Connexin 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

Precise 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

The 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

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

There 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

An 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

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

Aims 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

Aims 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

Aims 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)
How much of a priority is treating erectile dysfunction? A study of patients’ perceptions
Authors: Rance J. , Phillips C. , Davies S. , O'Malley B. , Zaman Q. , Price D.
Published: December 2004

Background Erectile dysfunction (ED) is one complication of diabetes for which the treatment is rationed. Despite considerable public debate there has been no formal assessment of the views of patients and sufferers of the priority of treating ED.

Aims To determine the perceptions of diabetic patients of the relative priority of treating ED in comparison with treatments for other diabetic complications and common medical conditions.

Methods Psychological measures were used to assess subjects’ perceptions of the relative importance of ED in comparison with eight other common problems (blindness, foot ulcers, high blood pressure, impotence, kidney disease, high cholesterol, migraine, mild indigestion and sleeping difficulties). The concept of willingness to pay was used to assess the amount per month participants would be prepared to pay for treatment for ED and other conditions. Four groups (controls, healthy diabetic men, impotent diabetic men and impotent diabetic men not in a sexual relationship) were studied.

Results Significant differences were found between the four groups with regard to the ranking of the importance of ED compared with other health problems. Impotent diabetic male patients were prepared to pay more for treatment for their condition than all other conditions except blindness and renal failure.

Conclusions Men with diabetes, in particular ED sufferers, believe ED has a major impact on quality of life and is as important to treat as many other conditions associated with diabetes.

Diabet. Med. 20, 205–209 (2003)
A nationwide study of continuous subcutaneous insulin infusion (CSII) in Denmark
Authors: Nørgaard K.
Published: December 2004

Aims To record the number of patients treated with continuous subcutaneous insulin infusion (CSII), the attitude to CSII treatment among diabetes care providers and the characteristics of pump users in Denmark.

Methods A questionnaire was mailed to all departments of endocrinology, internal medicine and paediatrics in Denmark (n = 73) to determine the number of diabetic patients treated with CSII and the attitudes of chief consultants to it. All patients using CSII were identified and data from their records collected.

Results Primarily Type 1 diabetic patients (n = 142) were treated with CSII, approx. 0.5% of patients in Denmark. The explanations given for this low frequency varied for non‐CSII and CSII‐using diabetologists. Both found lack of funding important. In addition, the non‐CSII‐using group had a perception that CSII was dangerous. The CSII‐using diabetologists found that no more patients were interested and that it did not significantly improve metabolic control. The mean age of pump users was 48.1 ± 10.5 years and the mean time wearing a pump 14.1 ± 6.3 years. Mean HbA1c was 7.9 ± 1.2% during CSII, with a significant difference among the 15 centres (P < 0.05) and a tendency to be lower in females (P = 0.07).

Conclusions CSII is infrequently used in Denmark despite pump users showing reasonably good metabolic control. The most common explanations for these low figures are lack of expertise and funding for CSII. If more patients in Denmark were to be offered pumps, education of healthcare providers would be needed and the funding would have to be clarified.
Cardiac autonomic dysinnervation and myocardial blood flow in long‐term Type 1 diabetic patients
Authors: Hattori N. , Rihl J. , Bengel F. M. , Nekolla S. G. , Standl E. , Schwaiger M. , Schnell O.
Published: December 2004

Aims The aim of the study was to assess scintigraphically the relationship between myocardial blood flow response and sympathetic dysinnervation in long‐term Type 1 diabetic patients. Effects of the iron chelator deferoxamine on myocardial blood flow were studied and they were investigated according to the presence of cardiac sympathetic dysfunction.

Methods Myocardial blood flow (MBF) was assessed with N‐13 ammonia positron emission tomography in 13 long‐term Type 1 diabetic patients and 13 control subjects at rest and in response to sympathetic stimulation (cold pressor test (CPT)). In diabetic patients, the study was repeated after preinfusion with deferoxamine. Furthermore, 123I metaiodobenzylguanidine (MIBG) scintigraphy was applied to assess regional cardiac sympathetic dysinnervation (uptake score 1 = normal, homogeneous uptake … 6 = no uptake).

Results In diabetic patients, MBF increased in response to CPT from 78 ± 18 ml/100 g/min to 84 ± 26 ml/100 g (8%, P < 0.001). Control subjects demonstrated an increase from 63 ± 17 ml/100 g to 84 ± 26 ml/100 g (33%, P < 0.001), respectively. Resting MBF was higher in diabetic patients than in control subjects (P < 0.001). In diabetic patients, increase in MBF in response to CPT was significant in regions with a MIBG uptake score of ≤ 3. Regions with a MIBG uptake score of > 3 did not exhibit a significant increase in MBF in response to CPT. After administration of deferoxamine, the increase in MBF in response to CPT was 23% and the magnitude of increase was related to the MIBG uptake score (r = 0.40, P < 0.0001).

Conclusions Myocardial blood flow response to sympathetic stimulation is significantly impaired in long‐term Type 1 diabetes. After preinfusion with deferoxamine the impairment is partially reversed and a relationship between myocardial blood flow and the extent of cardiac sympathetic dysfunction is observed.

Diabet. Med. 20, 375–381 (2003)