bluuebunny/crossref_metadata_2025 huggingface dataset:
Extensive structure–activity studies of lactam derivatives of MT‐II and SHU‐9119: their activity and selectivity at human melanocortin receptors 3, 4, and 5
Authors: Grieco P. , Balse‐Srinivasan P. , Han G. , Weinberg D. , MacNeil T. , Van der Ploeg L. H. T. , Hruby V. J.
Published: October 2003

Abstract: The melanocortin system is involved in the regulation of several diverse physiologic pathways. Recently we have demonstrated that replacing His6 by Pro6 in the well‐known antagonist SHU‐9119 resulted in a potent agonist at the hMC5R (EC50 = 0.072 nm) with full antagonist activity at the hMC3R and the hMC4R. We have designed, synthesized, and pharmacologically characterized a series of peptide analogs of MT‐II and SHU‐9119 at the human melanocortin receptors MC3R, MC4R and MC5R. All these peptides were modified at position 6 with a Pro instead of a His residue. In this study, we have identified new scaffolds which are antagonists at the hMC4R and hMC3R. Additionally, we have discovered a new selective agonist at the hMC4R, Ac‐Nle‐c[Asp‐Pro‐D‐Phe‐Arg‐Trp‐Lys]‐Pro‐Val‐NH2 (6, PG‐931) which will be useful in further biologic investigations of the hMC4R. PG‐931 was about 100‐fold more selective for the hMC4R vs. the hMC3R (IC50 = 0.58 and 55 nm, respectively). Some of these new analogs have exceptional biologic potencies at the hMC5R and will be useful in further efforts to differentiate the substructural features responsible for selectivity at the hMC3R, hMC4R, and hMC5R.
Quantification of contact surface pressure exerted during external cephalic version
Authors: Leung Tak Yeung , Sahota Daljit Singh , Fok Wing Yee , Chan Lin Wai , Lau Tze Kin
Published: October 2003

Background.  The amount of force exerted on the uterus and fetus during external cephalic version (ECV) may be associated with fetal effects or complications. We have designed an instrument to quantify the contact pressure exerted during the performance of ECV, as an indirect measurement of the applied force.

Methods.  We have designed a pair of custom‐made gloves. Each glove contains 16 piezo‐resistive sensors positioned on the palmer surface of the fingers, thenar and hypothenar areas. Pressure readings were recorded simultaneously from all sensors every 0.22 s during each version procedure. Each recording was analyzed with a computer program written according to specified algorithms to ascertain the number of attempts in a version operation, and the duration and pressure changes of each attempt during the operation.

Results.  Ten subjects having a singleton breech presentation at term underwent an operation of ECV. The number of attempts of version in each operation ranged from one to four. The median pressure–time integral and the duration of an attempt were 19 227 mmHg s (range 5089–42 597 mmHg s) and 42.5 s (range 11.9–80.3 s), respectively. The median pressure–time integral of a whole version operation was 38 110 mmHg s (range 5089–107 511 mmHg s). Subjects with a failed version operation received a higher pressure–time integral (p < 0.05). The number of attempts of each operation was accurately identified by the program.

Conclusions.  Measurement of force applied during ECV can be quantified indirectly in terms of contact surface pressure. The indirect measurement of the applied force may further improve the safety of this procedure by preventing excessive use of force by the operator.
Antibiotic susceptibility of putative periodontal pathogens in advanced periodontitis patients
Authors: Kleinfelder J. W. , Müller R. F. , Lange D. E.
Published: October 2003

Abstract. In the present study, the antibiotic susceptibility of most prevalent micro‐organisms in advanced periodontitis patients was evaluated. In 56 patients, pooled subgingival plaque samples were taken from the deepest site of each quadrant and were cultivated anaerobically. From each patient, the 4 most frequently encountered types of bacterial colonies were subcultured and identified (Rapid ID 32 A). From all bacterial species identified in the 224 subcultures, the 4 most prevalent were used for susceptibility testing to tetracycline, metronidazole and amoxicillin/clavulanate using the E Test. The most prevalent microorganisms were Fusobacterium nucleatum (38/214), Peptostreptococcus micros (33/214), Prevotella oralis (33/214) and Porphyromonas gingivalis (32/214). Regarding antibiotic susceptibility it could be shown that minimal inhibitory concentration (MIC) in all cases was below antibiotic concentrations achievable in gingival crevicular fluid. However, antibiotic resistance was seen in 3 to 29% of the investigated microorganisms.
Bacteremia after dental treatment in mentally handicapped people
Authors: Messini M. , Skourti I. , Markopulos E. , Koutsia‐Carouzou C. , Kyriakopoulou E. , Kostaki S. , Lambraki D. , Georgopoulos A.
Published: October 2003

Abstract. Bacteremia may occur after disruption of the oral mucous membrane, particularly after dental treatment. 18 mentally handicapped patients who underwent dental treatment with general anesthesia were included in our study. None of the patients had general illnesses or received antibiotic protection. From each patient several blood samples were drawn aseptically during dental treatment and cultured. The majority of aerobic bacteria recovered belonged to Streptococcus sp and Gemella sp., anaerobic bacteria mainly belonged to Porphyromonas gingivalis and Peptostreptococcus sp. Resistance of the isolated bacteria to penicillin as well as to oxacillin, erythromycin and Co‐trimoxazole was substantial. The highest resistance rate could be shown against fucidic acid.
Cell division, synthetic capacity and apoptosis in periodontal lesions analysed by in situ hybridisation and immunohistochemistry
Authors: Koulouri O. , Lappin D. F. , Radvar M. , Kinane D. F.
Published: October 2003

Abstract. In this study, we investigated the synthetic and proliferative activity of infiltrating mononuclear cells in sections of granulation tissue from periodontitis lesions in both adult periodontitis (AP) and early onset periodontitis (EOP) patients. We also investigated the role of apoptosis in the remodelling of the inflamed tissue. We utilised a Ki‐67 antigen specific antibody and a histone messenger RNA (mRNA) probe to detect cells undergoing cell division in the sections. Oligonucleotide probes for 28S ribosomal RNA and for the detection of poly A mRNA were utilised to detect cells with synthetic capacity. Apoptosis was determined using terminal transferase labelling of fragmented DNA with Biotin labelled dUTP. Biopsies of granulation tissue were obtained from 9 AP patients, from 10 EOP patients and for comparative purposes, biopsies of gingival tissue from 4 patients with AP. There were no differences regarding the relative proportions of cells with synthetic capacity or in the numbers of dividing cells in the periodontitis tissue sections. However, we observed an increase in the number of dividing cells in the AP granulation tissues compared to the AP gingival sections and that these cells were predominantly fibroblast like in appearance. Apoptotic cells consisted mainly of connective tissue cells; mainly fibroblasts with few if any leukocytes being apoptotic other than polymorphonuclear leukocytes. Only a few cyto‐phagocytic macrophages were ever observed in the gingival and granulation tissues. We conclude that the turnover of infiltrating leukocytes in inflamed periodontal tissue is low, that they probably arrive at this site by recruitment from distant lymph nodes, and that neither cell division nor programmed cell death significantly alter the numbers of inflammatory cells. On the other hand, fibroblast apoptosis and cell division occur within the periodontium as these are typical processes in the normal turnover and remodelling of these tissues.
Ursodeoxycholic acid treatment of idiopathic thrombocytopenic purpura with liver dysfunction
Authors: Koike Michiaki , Sekigawa Iwao , Ogawa Kaol , Iida Noboru , Oshimi Kazuo
Published: October 2003

Abstract: Ursodeoxycholic acid (UDCA) is known to reduce immunoglobulin from B cells and cytokine production from T cells. We found that UDCA increased the platelet count in two idiopathic thrombocytopenic purpura (ITP) patients who have liver dysfunction. UDCA was tolerated and did not cause diarrhea in the amounts used. Further investigation is needed to evaluate the effectiveness of UDCA in ITP patients.
Ecological strategies of ectomycorrhizal fungi of Salix repens: root manipulation versus root replacement
Authors: Heijden E. W. van der , Kuyper Th. W.
Published: October 2003

The ecological significance of a range of ectomycorrhizal fungal species, associated with Salix repens, was investigated under controlled conditions. Different ectomycorrhizas increased plant benefits in various ways. Effects of 12 ectomycorrhizal fungi on short‐term (12 weeks) and long‐term (20 and 30 weeks) plant performance were compared. Different fungi increased plant benefits in different ways and none exerted the full range of mycorrhizal benefits. Two strategies of EcM fungi were recognized, root manipulation and root replacement. Species (Hebeloma, Cortinarius spp.) with a root manipulation strategy strongly increased root length and had a more effective nitrogen economy than species with the root replacement strategy (Laccaria, Paxillus spp.). As a consequence of these different strategies two parameters of nutrient acquisition, viz. nutrient inflow per unit root length (efficiency) and total shoot nutrient uptake (effectiveness) were not correlated. Differences in magnitude of mycorrhizal response were not related to the amount of root colonization. Only in the short term was plant nutrient content positively correlated with root length colonized. Over a whole growing season plant nutrient content could not be predicted from root length colonized. Effects of mycorrhizal fungi on root manipulation also occurred with aqueous extracts of the fungus and, hence, were partly independent of the formation of ectomycorrhizas.
Direct and indirect effects of UV radiation on benthic communities: epilithic food quality and invertebrate growth in four montane lakes
Authors: Tank Suzanne E. , Schindler David W. , Arts Michael T.
Published: October 2003

The direct harmful effects of ultraviolet radiation (UVR) on benthic and planktonic organisms have been well studied in aquatic systems. Less clear, however, is how UVR might affect aquatic communities through its effects on trophic interactions. The focus of this study was twofold: first, to examine the direct effect of UVR on benthic invertebrates and epilithon, the rock‐dwelling matrix of algae, bacteria, viruses, fungi and detritus, and second, to examine the indirect effect of UVR‐mediated shifts in epilithic food quality on epilithic consumers. Food quality was assessed by measuring carbon to nutrient ratios and the concentration of polyunsaturated fatty acids (PUFA) in the epilithic matrix; the effect of its change on epilithic consumers was measured using a feeding experiment. The study was conducted in four montane lakes, where downwelling UVR can be intense. Of these lakes, the benthic community of only one was strongly affected by UVR. In this lake, exposure to UVR decreased epilithic accrual and invertebrate colonization, and, contrary to our expectations, increased food quality in the shallows through decreased carbon to phosphorus ratios and increased PUFA concentrations. In another of the four study lakes, the feeding experiment showed no significant difference in growth rates between invertebrates fed UVR‐exposed and UVR‐shielded epilithon, or invertebrates directly exposed to or shielded from UVR. This study demonstrates that although UVR can play an important role in structuring the trophic dynamics of benthic communities, its effects will not be constant across systems, or important in all environments.
Stochastic relations between species richness and the variability of species composition
Authors: Stevens M. Henry H. , Petchey Owen L. , Smouse Peter E.
Published: October 2003

Ecological communities change over time and space, and ecologists have long suggested that biodiversity might influence the rate of change. Here we cast new light on this question by demonstrating statistical covariation between species richness and the variability of species abundances and identities within a community (compositional variability). We provide a new analytical framework for several previously published measures of ecosystem functioning and compositional variability. We derive three related variances, each of which measures compositional variability due solely to stochastic sampling processes. Our analyses show that whether relations between species richness and compositional variability are positive, negative or zero, depends on two factors. Not only does the particular variance used affect the relation, but, more importantly, the underlying determinants of species richness can strongly affect the stochastic relations between species richness and compositional variability. This analysis makes clear for the first time how species richness should correlate with important measures of community variability, even in the absence of systematic processes.
The distance dependence prediction of the Janzen‐Connell hypothesis: a meta‐analysis
Authors: Hyatt Laura A. , Rosenberg Michael S. , Howard Timothy G. , Bole Gregory , Fang Wei , Anastasia Jean , Brown Kerry , Grella Rebecca , Hinman Katharine , Kurdziel Josepha P. , Gurevitch Jessica
Published: October 2003

The Janzen‐Connell hypothesis explains the maintenance of tropical diversity through the interacting effects of parent‐centered dispersal patterns and distance‐ and density‐dependent propagule survival. These effects were thought to support regular spacing of species within tropical forest, enhancing diversity. One of the predictions of the hypothesis is that seed and seedling survival should improve with increased parental distance. Although there are many independent tests of this hypothesis for individual species, there are few synthetic studies that have brought these data together to test its validity across species. This paper reports the results of a meta‐analysis of the effect of distance on enhancing propagule survival, employing an odds‐ratio effect size metric. We found no general support for the distance‐dependent prediction of the hypothesis, and conclude that further testing to explore this hypothesis as a diversity‐maintaining mechanism is unnecessary. However, we did find that distance from parent slightly reduces survivorship in the temperate zone, as contrasted with the tropics, and we saw stronger evidence in support of the hypothesis for seedlings than for seeds. The phenomenon of enhanced propagule survival with distance from the parent may be important for the population biology of particular species, but it is not a general phenomenon across communities, life history stages or life forms.
A mechanistic examination of diversity‐stability relationships in annual plant communities
Authors: Valone Thomas J. , Hoffman Catherine D.
Published: October 2003

While recent theoretical work has demonstrated several mechanisms whereby more diverse communities can exhibit greater temporal stability, empirical examinations have been few and the subject of much debate. We show that the temporal stability of natural summer and winter annual plant communities, at spatial scales of 0.25 m2and 0.25 ha, tends to increase with community richness. Furthermore, more diverse communities exhibited greater stability because they contained a greater abundance of individuals (overyielding effect). Statistical averaging (the portfolio effect) and negative covariances between species (insurance and competition effects) did not enhance stability. Relationships between diversity and stability tended to be weak and were significant only at the smaller spatial scale. Because more diverse communities contained higher densities of individuals, the effect of diversity per se on stability was unclear and likely small. If overyielding is common in other ecological systems, the loss of individuals and biodiversity may often result in increased variation in ecological communities.
Spatial occurrence and colonisations in patch‐tracking metapopulations: local conditions versus dispersal
Authors: Snäll T. , Ribeiro Jr. P. J. , Rydin H.
Published: October 2003

We studied the relative importance of local variables and dispersal for the occurrence and colonisation of the epiphytic bryophytes Orthotricum speciosum (spore dispersed), and O. obtusifolium (spore and asexual gemmae) on aspen trees (‘patches’) in two forest landscapes (one old‐growth and one fragmented) using multiple logistic regression. The relative importance of dispersal was quantified as the reduction of residual deviance for a connectivity variable. In modelling dispersal, we assumed that trees with low local abundance were recent colonisations, and that trees with high local abundance were diaspore sources for colonisation. The occurrence of O. speciosum in the fragmented landscape was most affected by shading, but also by connectivity, aspen diameter and vitality. In the old‐growth landscape, connectivity was the single most important variable for recent colonisations, but its effect was lower than the sum of the effects of all local environmental variables. The occurrence of O. obtusifolium in the fragmented landscape was related to similar variables but the relative importance of these variables was different, and connectivity did not affect the probability of a recent colonisation in this species. We describe the epiphyte‐tree system in the patch‐tracking metapopulation model. In this model colonisations are distance dependent, but in contrast to the classical metapopulation model local extinctions are caused by deterministic patch destruction – once the epiphyte has colonised the tree it remains until the tree dies.
The effect of food supplementation on reproductive success in bumblebee field colonies
Authors: Pelletier Luc , McNeil Jeremy N.
Published: October 2003

Food availability is a major component of habitat quality. For bumblebee field colonies, it is unknown to what extent reproductive success is limited by food availability relative to other factors such as parasites. To assess the importance of food availability, we carried out a field experiment in the Quebec City area, Canada, in 1999 and 2000, using 45 colonies ofBombus impatiensandB. ternarius. Colonies whose nectar and pollen supplies were increased regularly throughout the season reached larger sizes (in number of workers) and had a higher reproductive success than controls, by 51% and 86% respectively. In particular, food supplementation increased the number of males produced and the probability of producing gynes (young queens). The sex ratio was highly skewed in favour of males overall, and the relative proportion of gynes increased with food supplementation inB. ternarius, but not inB. impatiens. These results suggest that colonies ensure reproduction by producing some males and, given the opportunity (sufficient food availability), will produce gynes. Possible reasons for the increased success of food supplemented colonies are explored. However, despite some clear advantages of having larger food supplies such as the build‐up of larger worker populations, food supplementation did not appear to help colonies defend themselves against macroparasites because experimental and control colonies experienced similar levels of parasitism byPsithyrus,Fannia canicularis,Brachicoma deviaandVitula edmandsae.
Induction of phlorotannin production in a brown alga: defense or resource dynamics?
Authors: Jormalainen Veijo , Honkanen Tuija , Koivikko Riitta , Eränen Janne
Published: October 2003

Increase of phenolic secondary metabolites, phlorotannins, in brown algae due to gastropod grazing has been interpreted as an anti‐herbivore adaptation. Here we tested whether such a response could be due to changes in truly available resources for the alga, not by the grazing activity of snails as such. We allowed two species of snails, Theodoxus fluviatilis and Physa fontinalis to graze on Fucus vesiculosus. These species feed on epibiota and particulate matter on the thallus but do not eat the thallus of F. vesiculosus. We further simulated snail grazing by nutrient enhancement, removal of epibiota and by a combination of the two. Manipulations of nutrient and light availability revealed the crucial role of epibiota in mediating resource availability for F. vesiculosus. Nutrient enhancement alone increased epibiota and decreased phlorotannins. Cleaning the thallus resulted in increased growth, and together with nutrient enhancement also in a trade‐off with phlorotannins. Presence of T. fluviatilis on the thallus induced phlorotannin production, a response differing from the simulations of snail grazing. However, we suggest that the increase in phlorotannins may not be an induced defense but rather a consequence of a specific way of resource manipulation by this snail species. T. fluviatilis removes hyaline hairs that facilitate nutrient uptake. P. fontinalis did not remove hyaline hairs and the response of the alga to its grazing was similar to the treatment where we mechanically removed epibiota suggesting that cleaning of the thallus is the major mechanism how this snail species affects F. vesiculosus. Genetic variation in phlorotannin concentrations highly exceeded the induced responses of simulated or real snail grazing. This casts doubt for the efficiency of induced phlorotannin production to act as a defense, but is not contradictory with the interpretation of phlorotannins responding to variation in resource availability.
Colonisation by a dominant ant facilitated by anthropogenic disturbance: effects on ant assemblage composition, biomass and resource use
Authors: Gibb Heloise , Hochuli Dieter F.
Published: October 2003

Dominant species are thought to regulate species composition and assemblage structure. Invasion by a dominant species is thus likely to alter assemblages and anthropogenic disturbance often facilitates such invasions. In this study we examined the association of a dominant ant, Iridomyrmex purpureus, native to south‐eastern Australia, with fire trails in national parks and its effects on ant assemblages. Association with fire trails was examined by comparing the numbers of I. purpureus nests on transects along fire trails with those in transects through surrounding vegetation. Ant assemblages and habitat characteristics of eight sandstone outcrops that supported colonies of I. purpureus were compared with those on eight that did not in summer and autumn 2000. We examined ant species richness, abundance, composition and biomass using quadrats, and resource use with Acacia botrycephalus seeds placed on rock and in vegetation. I. purpureus nests were considerably more common along fire trails than in surrounding vegetation. Sites with I. purpureus had similar species richness to those without, but a lower abundance and biomass of other ants and a different assemblage composition. These differences could not be attributed to any differences in measured habitat characteristics. Ecologically similar species, particularly other species of Iridomyrmex, were less abundant in areas with I. purpureus. While the biomass of other species was suppressed in areas with I. purpureus, the biomass of the dominant was several times that of the assemblage of other ants, a pattern shared with assemblages invaded by exotic species. In areas with I. purpureus, seeds were removed more rapidly from rock, but not vegetation, indicating that resources on rock may be under‐exploited by other species. Regulation of invaded ant assemblages by this dominant ant is thus limited to functionally similar species, and this may be due to its use of resources that are unexploited in its absence.
Scale‐dependence and mechanisms of dispersal in freshwater zooplankton
Authors: Cohen Galeet M. , Shurin Jonathan B.
Published: October 2003

Communities of organisms form as a result of both interspecific and abiotic interactions within local habitat patches and dispersal among patches in a region. Local processes are expected to play a dominant role when dispersal occurs much more often than extinction. We performed two field experiments to examine rates and mechanisms of dispersal in freshwater pond zooplankton communities. First, we tested the effect of distance from a source on the rate of colonization of artificial habitat by placing wading pools at 5, 10, 30 and 60 m from two natural fishless ponds and observing the succession of zooplankton. Seventy‐eight percent of the species in the source ponds that were capable of living in the pools colonized at least once during the experiment. A new species was found in the pools on average once every four days, suggesting that colonization events occur on the order of days to weeks for many species. Colonization rates declined further from the source at one pond but not the other, and the effect of distance was relatively weak at both ponds. This suggests that many species disperse broadly over short distances. The second experiment tested the role of animal vectors for zooplankton dispersal by restricting access to the pools. Eight treatments were imposed that excluded potential animal vectors along a body size gradient from large mammals to small insects. While the treatments affected zooplankton colonization, many species invaded even when all animals larger than 1 mm were excluded. Animal vectors may therefore be less important for dispersal than wind. Our results suggest that zooplankton are highly effective dispersers over short distances, and can disperse via several mechanisms. Local interactions should therefore play a dominant role in structuring these communities at small regional scales.
Differential response of tellimagrandin II and total bioactive hydrolysable tannins in an aquatic angiosperm to changes in light and nitrogen
Authors: Gross Elisabeth M.
Published: October 2003

The submerged freshwater angiosperm Myriophyllum spicatum produces high amounts of polyphenols, especially gallotannins, with broad biological activity against insect herbivores, algae, cyanobacteria and heterotrophic bacteria. To test whether resource availability explains the intraspecific variability of these hydrolysable tannins, the impact of light and nitrogen on the production and release of total polyphenols and tellimagrandin II, the major allelochemical present in M. spicatum was investigated. Axenic cultures grown in a controlled environment allowed to exclude any effects of herbivores, epiphytes or pathogens on phenolic compounds. Light had a strong positive effect both on tissue‐bound and exuded polyphenolic compounds. Nitrogen availability neither influenced the total content of tissue‐bound polyphenols nor the exudation of phenolic compounds. In contrast, at low nitrogen and low light availability tissue concentrations of the major polyphenol tellimagrandin II increased. These findings are important considering the allelochemical activity of M. spicatum polyphenols, especially tellimagrandin II. The results are assessed in the context of the recent debate on the validity of the carbon‐nutrient balance hypothesis and possible other models.
A forehead mass present for 53 years after trauma in childhood
Authors: Cheng Yi‐Shing Lisa , Binnie William , Shroyer John , Bridges George
Published: October 2003

A 60‐year‐old man developed a mass on his forehead in his childhood. Histologic examination revealed a subcutaneous encapsulated cellular neoplasm consisting of mostly polygonal epithelioid cells, with abundant amphophilic cytoplasm and pleomorphic nuclei. There was one focal area of spindle cells. Numerous blood vessels of various sizes, small vacuoles and eosinophilic hyalinized material were also present. The morphologic features of the neoplasm did not fit with the typical features of any recognized pathologic entity. The subsequent immunohistochemical and electron microscopical evidence supported the diagnosis of epithelioid schwannoma, a rare variant of schwannoma that has not been reported in oral and maxillofacial pathology publications. The purpose of this report is to document a case and increase the awareness of this entity.
Cholesterol Loading Induces a Block in the Exit of VSVG from the TGN
Authors: Ying Ming , Grimmer Stine , Iversen Tore‐Geir , van Deurs Bo , Sandvig Kirsten
Published: October 2003

Recent work from our laboratory demonstrated that increased cellular cholesterol content affects the structure of the Golgi apparatus. We have now investigated the functional consequences of the cholesterol‐induced vesiculation of the Golgi apparatus and the role of actin for these changes. The results showed that cholesterol‐induced vesiculation and dispersion of the Golgi apparatus is a reversible process and that reversal can be inhibited by cytochalasin D, an actin‐disrupting reagent. Furthermore, electron microscopy revealed that jasplakinolide, which stabilizes actin filaments, prevented the dispersion, but not the vesiculation of the Golgi cisternae. Importantly, the different Golgi markers seemed to be separated even after vesiculation. To investigate whether transport through the different steps of the exocytic pathway was affected in cholesterol‐treated cells, we visualized ER to plasma membrane transport by using ts045‐VSVG‐GFP. In COS‐1 cells expressing ts045‐VSVG‐GFP increased cholesterol levels did not affect transport of VSVG into the vesiculated Golgi apparatus. However, increased levels of cholesterol resulted in retention of the nascent G protein in vesicles with the TGN‐marker TGN46. Biotinylation of cell surface molecules to quantify arrival of VSVG at the plasma membrane confirmed that cholesterol treatment inhibited export of the VSVG protein. In conclusion, the data show that transport of VSVG into/through a vesiculated Golgi is feasible, but that cholesterol loading inhibits exit of VSVG from the vesicles containing TGN markers. Furthermore, the data illustrate the importance of actin filaments for Golgi structure.
Molecular dissection of the amygdala and its relevance to autism
Authors: Zirlinger M. , Anderson D.
Published: October 2003

The limbic system, and in particular the amygdala, have been implicated in autism. The amygdala is a complex structure that in rodents consists of at least 12 different nuclei or subnuclei. A comparative analysis of amygdala neuroanatomy in normal vs. autistic brains would be aided by the availability of molecular markers to unambiguously recognize these different amygdala substructures. Here we report on the development of methods to identify genes enriched in the central, lateral and medial nuclei of the rodent amygdala. Our results suggest that laser‐capture microdissection of specific amygdala subnuclei, when combined with linear amplification of cRNA probes for oligonucleotide microarray hybridization, can efficiently identify genes whose expression is confined to these substructures. Importantly, many of these genes were missed in previous gene expression‐profiling experiments using whole amygdala tissue. The isolation of human orthologs of these subnucleus‐specific genes, and/or the application of these methods directly to human tissue, may provide useful markers for characterizing neuropathological correlates of autism, as well as for identifying molecular differences between normal and autistic brains.
The Dental Hygiene Program in Portugal
Authors: Luís HS , Ribeiro S , Albuquerque T
Published: October 2003

Abstract: The Dental Hygiene Program is a fairly recent addition in the field of the health professions in Portugal. In the past 19 years, the programme has developed community activities alongside with clinical work. This programme provides an education that is responsive, scientific and professional, in a learning environment that is dynamic, student‐centred and that encourages collaboration between students and faculty. The community activities play a major role in the curricula of the programme and allow the students to develop skills in working with a wide range of population groups and to attend to their specific needs. Dental hygienists are integrated in health teams and work under the supervision of a physician or a dentist. Among other responsibilities, the following functions are part of the scope of the profession: to participate in health education programmes and sensitise the population to the prevention of dental diseases, to participate in the planning, implementation, and evaluation of the public health programmes and to perform clinical treatment for prevention and control of gingivitis, periodontitis, and dental caries. An overview of the activities developed in the year 2002 and future perspectives are presented in this article.
New research paradigm
Authors: Perno Goldie M
Published: October 2003

Abstract:  Scientists are looking at a variety of ways to prevent disease and help insure wellness across the lifespan. Health and disease are linked to human behavior, environment, and biology. Biological influences are many, including a person's sex. Age‐old infectious diseases continue to warrant out attention, whether they are acute or chronic. Changing models of disease are focusing on quality of life issues, taking into account the physiological and social influences that affect one's life from cradle to grave. This article reviews recent discoveries in the area of antibiotics, premedication, genetics, obesity, tongue piercing, and tongue splitting. As oral health care professionals, dental hygienists should be aware of the latest trends in research, and models of disease prevention and maintenance of wellness.
Study on the Mechanism of the Bone Formation Process by 17β‐estradiol during Rat Bone Marrow Stromal Cell Culture
Authors: Sado Toshiyuki , Saito Shigeru , Morikawa Hajime
Published: October 2003

The aim of this study is to clarify the mechanism of bone formation by using 17β‐estradiol (E2) during rat bone marrow stromal cell culture. Stromal cells were separated from female rat femora (seven weeks old), and were cultured in an Eagle Minimal Essential Medium (MEM) containing 15% fetal calf serum (FCS). After confluence, the cells were subcultured in a MEM containing 15% FCS (sex steroids removed by charcoal treatment) with dexamethasone, Na betaglycerophosphate and ascorbic acid phosphate for 18 days. They were then cultured in medium containing E2 or insulin‐like growth factor‐Ι (IGF‐Ι) alone or with anti‐IGF‐Ι antibody. On the 14th day, the formation of white colored nodules showing positive ALP activity in ALP staining and showing calcium deposition in alizarin red S staining was observed in each culture system, indicating the beginning of calcification. The addition of E2 (10−7M or 10−8M), or IGF‐Ι (10 and 100 ng/ml) enhanced ALP activity and calcium content significantly, but 17α‐estradiol did not. Anti‐IGF‐Ι antibody significantly inhibited enhancing effects of E2 and IGF‐Ι on ALP activity and calcium deposition. Incubating with E2 alone (10−8M), the medium IGF‐Ι concentration and IGF‐I mRNA expression in the cells were significantly increased on days 10~14, but the expression of IGF‐Ι receptor mRNA had not changed. These results suggest that E2 participates in bone formation by promoting IGF‐Ι production in the bone marrow stromal cells just before calcification starts.
The interleukin‐25 gene located in the inflammatory bowel disease (IBD) 4 region: no association with inflammatory bowel disease
Authors: Büning C. , Genschel J. , Weltrich R. , Lochs H. , Schmidt H.
Published: October 2003

Genetic predisposition has been suggested to play an important role in the pathogenesis of inflammatory bowel diseases (IBDs). Linkage studies have identified a Crohn's disease susceptibility locus on chromosome 14 (14q11–12; IBD4). Interleukin‐25 (IL‐25) is a newly identified proinflammatory cytokine that has been shown to promote Th2 responses by inducing cytokines such as IL‐4, IL‐5 and IL‐13. The IL‐25 gene is located within this susceptibility region at 14q11.2. As IBDs are characterized by an imbalance of the Th1/Th2 cytokine response, we hypothesized that genetic alterations within the IL‐25 gene might contribute to IBD. First, direct sequencing of the coding regions of the IL‐25 gene in 40 patients with Crohn's disease or ulcerative colitis revealed only a newly reported polymorphism (c424C/A) in exon 2. Next, the frequency of this polymorphism was further investigated in 151 patients with Crohn's disease, 111 patients with ulcerative colitis, and 119 healthy controls to determine its clinical relevance. The genotypes of the c424C/A polymorphism did not reveal any significant differences between patients with Crohn's disease or ulcerative colitis and controls. Genoytype–phenotype relations in patients with Crohn's disease showed a comparable distribution of the c424C/A polymorphism in all subgroups of the Vienna classification. In summary, our data indicate that genetic alterations in the coding regions of the IL‐25 gene are unlikely to play a role in IBDs, but the c424C/A polymorphism in the IL‐25 gene should be investigated for a potential association with other chronic inflammatory and inherited disorders such as autoimmune diseases.
Complementary therapy practice: defining the role of advanced nurse practitioners
Authors: Patterson Christine , Kaczorowski Janusz , Arthur Heather , Smith Kiara , Mills Dorothy Anne
Published: October 2003

• The purpose of the study was to identify the current and perceived clinical role functions of advanced nurse practitioners (ANPs) within the complementary health paradigm and their learning needs.

• Participants were asked to identify their referral practices to complementary practitioners, current and perceived clinical activities with respect to six most popular complementary therapies, learning needs and concerns regarding their use.

• A random sample of 389 ANPs registered with the College of Nurses of Ontario participated in a mailed survey using a modified Dillman approach, an established method for improving response rate through repeated mailings.

• An overall response rate of 55.3% (215 out of 389 eligible participants) was achieved.

• The results show that ANPs are currently engaged in clinical activities involving these therapies, with a trend towards more participation in assessing the need for them and counselling on the risks and benefits.

• ANPs are interested in validating the use of these therapies and acquiring more knowledge on the scientific principles, evidence of efficacy, pharmacology and potential interactions with conventional medicine.
Left atrioventricular plane displacement determined by echocardiography: a clinically useful, independent predictor of mortality in patients with stable coronary artery disease
Authors: Rydberg E. , Erhardt L. , Brand B. , Willenheimer R.
Published: October 2003

Abstract. Rydberg E, Erhardt L, Brand B, Willenheimer R (Malmö University Hospital, University of Lund, Malmö, Sweden). Left atrioventricular plane displacement determined by echocardiography: a clinically useful, independent predictor of mortality in patients with stable coronary artery disease. J Intern Med 2003; 254: 479–485.

Background. Echocardiographically determined left atrioventricular plane displacement (AVPD) is strongly related to prognosis in patients with chronic heart failure and in postmyocardial infarction patients. We aimed at exploring whether AVPD, unlike ejection fraction, is related to mortality in patients with stable coronary artery disease (CAD).

Methods and results. Atrioventricular plane displacement was assessed by two dimensionally guided M‐mode echocardiography in the four and two chamber views, in 333 consecutive patients with stable CAD and an abnormal coronary angiogram. Patients were followed up for an average of 41 months. AVPD was lower in patients who died (n = 30, 9.0 %) compared with survivors (9.0 ± 2.2 vs. 11.5 ± 2.1 mm, P < 0.0001). Amongst patients with prior myocardial infarction (n = 184) AVPD was 8.7 ± 2.3 mm in those who died (n = 17) and 11.2 ± 2.3 mm in the survivors (P < 0.0001). In patients without prior myocardial infarction (n = 149), AVPD was 9.4 ± 2.1 (n = 13) and 11.8 ± 1.8 mm, respectively (P < 0.0001). Age, AVPD and four other echocardiographical variables correlated significantly with prognosis in univariate logistic regression analysis. In multiple logistic regression analysis only AVPD (P < 0.0001) correlated independently with mortality.

Conclusion. Echocardiographically determined AVPDis a clinically useful, independent prognostic tool in patients with stable CAD. The presence of a documented previous myocardial infarction does not influence this observation.
White Adipose Tissue: Getting Nervous
Authors: Fliers E. , Kreier F. , Voshol P. J. , Havekes L. M. , Sauerwein H. P. , Kalsbeek A. , Buijs R. M. , Romijn J. A.
Published: October 2003

Neuroendocrine research has altered the traditional perspective of white adipose tissue (WAT) as a passive store of triglycerides. In addition to fatty acids, WAT produces many hormones and can therefore be designated as a traditional endocrine gland actively participating in the integrative physiology of fuel and energy metabolism, eating behaviour and the regulation of hormone secretion and sensitivity. WAT is controlled by humoral factors, para‐ and intracrine factors and by neural regulation. Sympathetic nerve fibres innervate WAT and stimulate lipolysis, leading to the release of glycerol and free fatty acids. In addition, recent research in rats has clearly shown a functional parasympathetic innervation of WAT. There appears to be a distinct somatotopy within the parasympathetic nuclei: separate sets of autonomic neurones in the brain stem innervate either the visceral or the subcutaneous fat compartment. We therefore propose that the central nervous system (CNS) plays a major role in the hitherto unexplained regulation of body fat distribution. Parasympathectomy induces insulin resistance with respect to glucose and fatty acid uptake in the innervated fat depot and has selective effects on local hormone synthesis. Thus, the CNS is involved not only in the regulation of hormone production by WAT, but also in its hormone sensitivity. The developments in this research area are likely to increase our insights in the pathogenesis of metabolic disorders such as hypertriglyceridemia, diabetes mellitus type 2 and lipodystrophy syndromes.
The Effects of Neonatal Castration on the Subsequent Behavioural Response to Centrally Administered Arginine Vasopressin and the Expression of V1a Receptors in Adult Male Prairie Voles
Authors: Cushing B. S. , Okorie U. , Young L. J.
Published: October 2003

Centrally administered arginine vasopressin induces the formation of partner preferences in male prairie voles (Microtus ochrogaster). The expression of many vasopressin‐regulated behaviours is testosterone dependent. In this study, we tested the hypothesis that early exposure to gonadal steroids are necessary to establish the typical response of adult male prairie voles to exogenous vasopressin, predicting that adult males which were castrated neonatally would not form partner preferences in response to centrally administered vasopressin. We also examined the effect of neonatal castration on the expression of vasopressin (V1a) receptors. Voles were castrated on the day of birth (NEOCAST), sham‐castrated on the day of birth (NEOSHAM) or castrated as adults (ADULTCAST). With the exception of one group of neonatal sham males (NEOSHAM CON), which served as a control for the effects of vasopressin, as adults, all males received a 1‐µl intracerebroventricular injection of vasopressin (100 ng) in artificial cerebrospinal fluid. In addition, 2 weeks before testing, one group of neonatally castrated males received an implant of testosterone propionate (NEOCAST + TP). Between 60 and 90 days of age, an internal cannula was placed in the lateral cerebral ventricle and, 24 h later, males were injected with vasopressin. Subsequently, after an additional 15 min, males were cohabitated with a female ‘partner’ for 1 h. Immediately following cohabitation, males were placed in a Y‐shaped partner preference test apparatus for 3 h, in which the male had access to the ‘partner’ and a novel female, ‘stranger.’ Time spent with the partner versus the stranger was compared within and between treatments. The results were found to support our hypothesis as the NEOSHAM and ADULTCAST males formed partner preferences, spending more time with the partner, and they spent significantly more time with their partner than did NEOSHAM CON, NEOCAST or NEOCAST + TP males. Replacement of testosterone in neonatally castrated males did not restore partner preference formation in response to vasopressin in adult males. Finally, neonatal castration did not affect the distribution of V1a receptors.
Immunoreactive Galanin Expression in Ovine Gonadotropin‐Releasing Hormone Neurones: No Effects of Gender or Reproductive Status
Authors: Dufourny L. , Schofield N. , Skinner D. C.
Published: October 2003

The neuropeptide, galanin, has been implicated to play a significant role in numerous physiological functions, including reproduction. Studies on several species have shown that galanin enhances gonadotropin‐releasing hormone (GnRH)‐induced luteinizing hormone secretion. In rodents, a subset of GnRH neurones expresses galanin in a sexually dimorphic manner and it has been suggested that this may underpin the differences in GnRH secretion observed between the sexes. However, there are few data available for other species. Previous studies in sheep have shown that the distribution of GnRH neurones overlaps with galanin cells. The primary objectives of our study were to determine whether GnRH and galanin coexist in the sheep brain and, importantly, if a sex difference is apparent in the colocalization of these two peptides. Using immunocytochemistry coupled to high temperature antigen retrieval, we found that all GnRH neurones in the ovine brain colocalize with galanin. There is also a distinct population of galanin neurones that do not secrete GnRH. In addition, the distribution of galanin‐immunoreactive cells was similar to that previously reported for colchicine treated ewes and, in agreement with earlier studies, the number of GnRH neurones did not differ between rams and ewes or between ewes killed at different stages of the oestrous cycle. These results suggest that, in sheep, GnRH and galanin may be cosecreted but the functional significance of this coexpression and possible cosecretion remains to be elucidated.