bluuebunny/crossref_metadata_2025 huggingface dataset:
Evidence for post‐depletion sustainability in a mature bushmeat market
Authors: COWLISHAW GUY , MENDELSON SAMANTHA , ROWCLIFFE J. MARCUS
Published: June 2005

The trade in wild animals for meat, or ‘bushmeat’, is perceived as one of the most important threats to wildlife in the tropics. Unsustainable bushmeat extraction also threatens the loss of livelihoods. However, the long‐term persistence of the bushmeat trade, documented in Africa over several centuries, suggests that the trade can be sustainable. In this study, we investigate sustainability in a mature bushmeat market in West Africa (Takoradi, Ghana).

Our study, conducted over January and February 2000, combined biological and socio‐economic approaches. Offtake data, including information on species identity, capture location and sales price, were collected in a market survey. Species biological data, and the historical price of bushmeat and its substitutes (fish and domestic meat), were taken from the literature. The theoretical sustainable yield for each species was estimated using standard algorithms.

We tested the hypothesis that the current trade is unsustainable with four predictions: that (1) the number of animals extracted exceeds a theoretical sustainable yield, (2) larger taxa are depleted more heavily close to the city, (3) the price of bushmeat has outstripped inflation and (4) the price of alternatives, such as domestic meat and fish, has fallen relative to the price of bushmeat. None of these predictions were supported. There was therefore no evidence of unsustainability.

Analysis of market profiles and hunter reports suggest that the present pattern of sustainability is the result of a series of non‐random extinctions from historical hunting. Vulnerable taxa (slow reproducers) have been depleted heavily in the past, so that only robust taxa (fast reproducers), such as rodents and small antelope, are now traded. These robust taxa are supplied from a predominantly agricultural landscape around the city.

Synthesis and applications. The bushmeat trade can have a severe impact on species that are vulnerable to overexploitation. However, once these species have disappeared, the remaining species may be harvested sustainably. Bushmeat management policy might therefore be improved by adopting a two‐pronged approach in which vulnerable species are protected from hunting, but robust species are allowed to supply a sustainable trade. The productivity of agricultural landscapes for many bushmeat species indicates that these areas may play an important role in supporting a sustainable bushmeat trade.
Early impacts of forest restoration treatments on the ectomycorrhizal fungal community and fine root biomass in a mixed conifer forest
Authors: SMITH JANE E. , McKAY DONARAYE , BRENNER GREG , McIVER JIM , SPATAFORA JOSEPH W.
Published: June 2005

The obligate symbiosis formed between ectomycorrhizal fungi (EMF) and roots of tree species in the Pinaceae influences nutrient uptake and surrounding soil structure. Understanding how EMF respond to prescribed fire and thinning will assist forest managers in selecting fuel‐reducing restoration treatments that maintain critical soil processes and site productivity.

The response of EMF species richness, live fine root biomass and duff levels to various forms and combinations of thinning and burning was investigated in mixed ponderosa pine and Douglas fir stands in the Blue Mountains of Oregon. The below‐ground community composition and structure of EMF at the site was characterized using molecular methods.

The EMF community consisted of a large number of infrequently detected species. The distribution of a few abundant species (Cenococcumsp.,Pilodermasp.,Rhizopogon salebrosusandWilcoxina rehmii) in a majority of the treatments both before and after treatment application demonstrates that some EMF species survive or rapidly re‐establish after disturbance.

EMF species richness, live root biomass and duff levels were reduced significantly by prescribed fire treatments compared to the non‐burned treatments.

Synthesis and applications.These results indicate that prescribed fire results in a short‐term reduction in EMF species richness and live root biomass and may influence whether managers can achieve the desired future condition of stands with large‐tree retention and low fuel loads. EMF mortality and complete duff reduction after fire have been implicated with poor tree survival and slow stand recovery in forest ecosystems world‐wide. The results of this study, along with the recovery potential of a site, and the impending risk of stand‐replacing wildfire in stands differing in structure from historic conditions, bear consideration when reintroducing fire.
Evaluation of the ecological restoration potential of plant communities in Norway spruce plantations using a life‐trait based approach
Authors: HÉRAULT BRUNO , HONNAY OLIVIER , THOEN DANIEL
Published: June 2005

In Europe, intensively managed coniferous plantations rarely achieve similar nature conservation functions as deciduous woodlands. The ability to identify coniferous plantations that might be successfully converted to deciduous woodland is a key goal in forest management. The herbaceous plant community composition of mature plantations may be an accurate selection criterion for stands that are most suitable for initiating the conversion process to deciduous forest.

The herbaceous plant communities in Norway spruce plantations were analysed using a functional group approach. The analysis was conducted in three steps: (i) identification of emergent groups (EG) by multivariate classification; (ii) comparison of EG abundance between coniferous and deciduous stands (i.e. the target communities); (iii) partitioning the variation in EG abundance in coniferous plantations between forest management, local environmental and regional variables.

Seven EG were identified: two core forest groups (short geophytes and zoochoreous perennials), two groups from open habitats (annuals and helophytes) and three mixed groups (anemochoreous perennials, graminoids and short perennials).

Among the core forest groups, short geophytes were severely under‐represented in plantations (because of their low dispersal abilities and specific habitat requirements) while zoochoreous perennials were slightly more abundant (because of their good dispersal and competitive abilities).

Regional variables largely influenced the abundance of core‐forest EG. Restoration of communities rich in zoochoreous perennials is far easier than restoring short geophyte‐rich communities because of the different colonization abilities of these EG.

Forest management variables were of secondary importance for the restoration potential of plantations. Because generalist EG were favoured by low stand densities, forest practitioners should avoid large thinning operations.

Local environmental variables played a minor role in determining EG abundance. However, short geophytes preferred rather high soil pH values and were therefore negatively affected by acidification caused by coniferous litter.

Synthesis and applications. The performance of short geophytes is the key to conversion success of Norway spruce plantations to deciduous forest. Stands located on base‐rich soils and in landscapes with high forest connectivity are the most appropriate candidates for initiating the conversion process. For other types of stands, future work should explore the possibility of restoring other land‐use types, such as annually mown meadows.
Central GABAA but not GABAB Receptors Mediate Suppressive Effects of Caudal Hindbrain Glucoprivation on the Luteinizing Hormone Surge in Steroid‐Primed, Ovariectomized Female Rats
Authors: Singh S. R. , Briski K. P.
Published: June 2005

The neurochemical mechanisms that link caudal hindbrain glucoprivic‐‘sensitive’ neurones with the forebrain gonadotrophin‐releasing hormone (GnRH)‐pituitary luteinizing hormone (LH) axis remain unclear. Available studies indicate that the amino acid neurotransmitter, γ‐aminobutyric acid (GABA), inhibits reproductive neuroendocrine function, and that caudal fourth ventricular administration of the glucose antimetabolite, 5‐thioglucose (5TG), enhances GABA turnover within discrete septopreoptic structures that regulate LH secretion. The current experiments utilized the selective GABAA and GABAB receptor antagonists, bicuculline and phaclofen, as pharmacological tools to investigate whether one or both receptor subtypes function within neural pathways that suppress GnRH neuronal transcriptional activation and LH release during central glucose deficiency. During the ascending phase of the afternoon LH surge, groups of steroid‐primed, ovariectomized female Sprague‐Dawley rats were pretreated by lateral ventricular administration of bicuculline, phaclofen, or vehicle only, before fourth ventricular injection of 5TG or vehicle. The data indicate that, 2 h after 5TG treatment, Fos immunoexpression by rostral preoptic GnRH neurones and plasma LH levels were diminished relative to the vehicle‐treated controls, and that inhibitory effects of 5TG on these parameters were attenuated by pretreatment with bicuculline, but not phaclofen. These results demonstrate that central GABAA, but not GABAB receptor stimulation during hindbrain glucoprivation, is required for maximal inhibition of reproductive neuroendocrine function by this metabolic challenge. The current studies thus reinforce the view that central GABAergic neurotransmission mediates regulatory effects of central glucoprivic signalling on the GnRH‐pituitary LH axis.
The Effect of Adrenalectomy on Ghrelin Secretion and Orexigenic Action
Authors: Proulx K. , Vahl T. P. , Drazen D. L. , Woods S. C. , Seeley R. J.
Published: June 2005

Ghrelin is an orexigenic peptide made both in the periphery and in the central nervous system. Relatively little is known about the factors that regulate ghrelin secretion. Because both ghrelin and glucocorticoids are increased during fasting, we hypothesised that ghrelin secretion from the stomach is stimulated by glucocorticoids. Plasma ghrelin concentrations were determined by radioimmunoassay in fed and fasted adrenalectomised (ADX) and sham‐operated rats. Fasting plasma ghrelin concentrations were significantly increased in ADX relative to sham rats and were normalised by glucocorticoid replacement. Several lines of evidence suggest that the orexigenic action of ghrelin is mediated through neuropeptide Y (NPY)/agouti‐related peptide (AgRP) neurones. Because ADX reduces the orexigenic actions of NPY and AgRP, we hypothesised that ADX would also reduce the orexigenic action of ghrelin. Food intake was assessed in ADX and sham rats following an intra‐third‐ventricular injection of either saline or ghrelin (1, 5 or 10 µg in 2 µl). ADX rats were equally sensitive to the orexigenic action of ghrelin compared to sham rats. Given that ghrelin has been shown to stimulate glucocorticoid secretion, the current data imply the existence of a regulatory feedback loop whereby glucocorticoids inhibit further ghrelin secretion. The results also suggest that, unlike the orexigenic effects of NPY and AgRP, the ability of ghrelin to stimulate food intake is maintained in ADX rats.
Expression of GABAB Receptors in Magnocellular Neurosecretory Cells of Male, Virgin Female and Lactating Rats
Authors: Richards D. S. , Villalba R. M. , Alvarez F. J. , Stern J. E.
Published: June 2005

GABA is one of the key neurotransmitters that regulate the firing activity of neurones in the supraoptic (SON) and paraventricular (PVN) nuclei. In the present study, we used immunohistochemical techniques to study the distribution and subcellular localisation of metabotropic GABAB receptors in magnocellular neurones in the SON and PVN. Robust GABAB receptor immunoreactivity (GABABR; both subunit 1 and subunit 2 of the heterodimer), was observed in the SON and PVN. At the light microcope level, GABABR immonoreactivity displayed a clustered pattern localised both intracytoplasmically and at the plasma membrane. Densitometry analysis indicated that GABABR immunoreactivity was significantly more intense in vasopressin cells than in oxytocin cells, both in male, virgin female and lactating rats, and was denser in males than in virgin females. Light and electron microscope studies indicated that cytoplasmic GABABR was localised in various organelles, including the Golgi, early endosomes and lysosomes, suggesting the cycling of the receptor within the endocytic and trafficking pathways. Some smaller clusters at the level of the cell plasma membrane were apposed to glutamic acid decarboxylase 67 immunoreactive boutons, and appeared to be colocalised with gephyrin, a constituent protein of the postsynaptic density at inhibitory synapses. The presence of GABABR immunoreactivity at synaptic and extrasynaptic sites was supported by electron microscopy. These results provide anatomical evidence for the expression of postsynaptic GABAB receptors in magnocellular neurosecretory cells.
Measuring Seasonal Time within the Circadian System: Regulation of the Suprachiasmatic Nuclei by Photoperiod
Authors: Johnston J. D.
Published: June 2005

Day‐length (photoperiod) is the primary environmental signal used to synchronise endogenous rhythms of physiology and behaviour. In mammals, the suprachiasmatic nuclei (SCN) of the hypothalamus house the master circadian clock. The SCN incorporate photoperiodic information and therefore measure both daily and seasonal time. Over the past decade, there have been significant advances in the understanding of the molecular basis of circadian clocks. It is now becoming apparent that the core molecular clock mechanism is itself regulated by photoperiod, although there is currently debate as to how this occurs. One recent model proposes that distinct groups of core ‘clock genes’ are associated with either morning or evening phases of the daily light/dark cycle. However, the validity of associating particular genes to morning and evening has been questioned. This article reviews the evidence for photoperiodic regulation of circadian clock function and then discusses alternative models that may explain the available data.
Neuroendocrine Regulation of Prolactin Secretion During Late Pregnancy: Easing the Transition into Lactation
Authors: Andrews Z. B.
Published: June 2005

Prolactin is an anterior pituitary hormone critical for maintaining pregnancy and lactation. Under normal conditions, prolactin secretion is tightly regulated by inhibitory dopaminergic neuronal systems within the mediobasal hypothalamus in a process known as short‐loop negative feedback. This review focuses on neuroendocrine adaptations to prolactin negative feedback during late pregnancy. It is suggested that, in terms of prolactin regulation, late pregnancy is a transition period into lactation because many of the neuroendocrine adaptations promoting hyperprolactinemia in lactation develop during late pregnancy. As a consequence, the maternal brain is geared to provide unrestrained prolactin release critical for milk production, maternal care and thus survival of the offspring before parturition. The mechanisms responsible for these changes are discussed.
Penetration of ceftiofur into sterile vs. Mannheimia haemolytica‐infected tissue chambers in beef calves after subcutaneous administration of ceftiofur crystalline free acid sterile suspension in the ear pinna
Authors: WASHBURN K. , JOHNSON R. , CLARKE C. R. , ANDERSON K. , LUCAS M. , BRYSON W. , ROBINSON J. , DAME K. , HUBBARD V. , CALLAHAN K. , ROBB E.
Published: June 2005

The effect of Mannheimia haemolytica infection on the penetration of ceftiofur and desfuroylceftiofur metabolites into tissue chambers was studied in cattle after subcutaneous administration of ceftiofur crystalline free acid sterile suspension (CCFA‐SS). Four tissue chambers were implanted subcutaneously in each of 12 calves. Approximately 45 days after implantation, two chambers were inoculated with M. haemolytica (106 colony‐forming units per chamber) while the remaining two chambers were inoculated with sterile phosphate‐buffered saline. Twenty‐four hours after inoculation, CCFA‐SS was administered subcutaneously in the middle third of the caudal ear pinna of each calf. Chamber fluid and blood samples were collected at predetermined times for 10 days following dosing and analyzed for ceftiofur and desfuroylceftiofur metabolites by high‐performance liquid chromatography. Concentrations of ceftiofur and desfuroylceftiofur metabolites in plasma and tissue chamber fluid remained above a threshold of 0.2 μg/mL for at least 8 days. Infected tissue chamber fluid concentrations of ceftiofur and desfuroylceftiofur metabolites were significantly higher than those in non‐infected tissue chamber fluid, which correlated with significantly higher total protein concentration in infected tissue chambers. These results indicate that single subcutaneous administration of CCFA‐SS at 6.6 mg/kg can be expected to provide effective therapy of susceptible bacterial infections for a period of at least 1 week.
l‐Bupivacaine 0.5% vs. racemic 0.5% bupivacaine for caudal epidural analgesia in horses
Authors: DEROSSI R. , MIGUEL G. L. S. , FRAZÍLIO F. O. , NUNES D. B. , KASSAB T. A.
Published: June 2005

Bupivacaine is available as a racemic mixture of its enantiomers,d‐bupivacaine andl‐bupivacaine (LB). The aim of this randomized, double‐blind study was to investigate the clinical efficacy and safety of S(−)‐bupivacaine compared with standard racemic bupivacaine (RB) in horses under caudal epidural analgesia. Two treatments were administered to each horse, with a 2‐week interval between subsequent treatments. Treatment 1 consisted of 0.5% LB at a dose of 0.06 mg/kg of body weight, and treatment 2 consisted of 0.5% RB at a dose of 0.06 mg/kg of body weight. Epidural injections were given in all animals between the first and second coccygeal vertebra. Heart rate (HR), arterial pressures, respiratory rate (RR), rectal temperature (RT), analgesia, and motor blocking were determined before drug administration (basal) and 5, 10, 15 and 30 min after drug administration, and at 30 min intervals thereafter. There were no significant differences between the two treatments in the quality of sensory and motor block. The duration of analgesia was 320 ± 30 min (mean ± SD) for RB and 360 ± 42 min for LB. HRs and RRs, arterial pressures and RT did not change (P < 0.05) significantly from basal values after epidural administration of LB or RB. This study supports that 0.5% LB is an effective alternative to RB in caudal epidural analgesia in conscious, standing horses. The use of LB vs. RB warrants further investigation, particularly for long‐lasting surgery in the perineal region.
Effects of moxifloxacin on QT interval in conscious dogs
Authors: MITTELSTADT S. W. , HART S. M.
Published: June 2005

Moxifloxacin has been shown to induce QT prolongation in both clinical and preclinical models. However, the ability to observe this effect at clinically relevant concentration in normal conscious dogs has not been reported. The purpose of this study was to investigate the effects of moxifloxacin on the QT interval in conscious, healthy dogs.

Four male mongrel dogs were chronically instrumented for the measurement of arterial blood pressure, left ventricular blood pressure, cardiac output, electrocardiograms (ECGs), and body temperature. Animals were administered a 1‐h i.v. infusion of moxifloxacin once per day via a catheter in the cephalic vein. Each dog received all doses (0, 1, 10, 25 and 50 mg/kg) in an escalating fashion.

Moxifloxacin caused a statistically significant increase in arterial blood pressure at 50 mg/kg. A dose–response effect on QT and QTc prolongation was observed. A statistically significant prolongation in the QT interval was observed at 10, 25 and 50 mg/kg and a prolongation of QTc was observed at 25 and 50 mg/kg. These effects occurred at clinically relevant plasma concentrations. This study demonstrate that a study design with four dogs was sensitive enough to measure moxifloxacin‐induced QT prolongation at clinically relevant plasma concentrations.
Studies on itraconazole delivery and pharmacokinetics in mallard ducks (Anas platyrhynchos)
Authors: TELL L. A. , CRAIGMILL A. L. , CLEMONS K. V. , SUN Y. , LAIZURE S. C. , CLIFFORD A. , INA J. H. , NUGENT‐DEAL J. P. , WOODS L. , STEVENS D. A.
Published: June 2005

Avian aspergillosis is commonly treated with itraconazole (ITZ). This paper describes two studies using mallard ducks (Anas platyrhynchos). The first study evaluated in vivo release of ITZ from subcutaneously injected controlled‐release gel formulations and the second study compared pharmacokinetic parameters for two ITZ oral suspensions. ITZ‐A suspension was prepared by mixing contents of commercially available capsules with hydrochloric acid and orange juice. ITZ‐B suspension was prepared by dispersing the complex of the drug with hydroxypropyl‐β‐cyclodextrin in water. Concentrations of ITZ and its active metabolite, hydroxyitraconazole (OH‐ITZ), in plasma and tissue samples were measured using high‐performance liquid chromatography. In the second study, drug concentrations in plasma samples were also analyzed using a bioassay. After administration of two ITZ controlled‐release formulations, plasma and tissue concentrations of ITZ and OH‐ITZ were either very low (≤52 ng/mL) or undetectable. Exceptions included skin, subcutaneous fat, and muscle adjacent to the injection site. The drug from ITZ‐A and ITZ‐B suspensions was absorbed after oral administration. ITZ pharmacokinetic parameters for both suspensions in mallard ducks were similar and the bioassay successfully measured ITZ equivalents in plasma samples from ducks.
Comparison of topical lidocaine/prilocaine anesthetic cream and local infiltration of 2% lidocaine for episioplasty in mares
Authors: ERKERT R. S. , MACALLISTER C. G. , CAMPBELL G. , PAYTON M. E. , SHAWLEY R. , CLARKE C. R.
Published: June 2005

Local anesthesia and tissue inflammation associated with lidocaine infiltration and lidocaine/prilocaine topical anesthetic cream for episioplasty in mares were compared. Twenty‐two mares were randomly assigned to lidocaine or lidocaine/prilocaine topical anesthetic cream treatment groups. Perineum and vulva were cleaned, 8–12 g (approximately 1 g/cm per side of vulva) of topical anesthetic cream was applied, and the area was covered by plastic wrap 30 min prior to beginning procedure. Alternately, lidocaine was injected (1 mL) every centimeter just prior to the procedure. Episioplasty was conducted using standard methods, but employing simple interrupted sutures. Horses were not sedated and use of a twitch was recorded. Four millimeter punch biopsies were harvested 1, 3, and 10 days following episioplasty and scored for degree of inflammation by a blinded pathologist. Clinical inflammation scores were assigned when biopsies were obtained. Seven of 11 horses receiving lidocaine infiltration required twitching, but none of the horses that received the anesthetic cream required twitching. Six of 11 and seven of 11 of the lidocaine and anesthetic cream groups, respectively, required twitching for episioplasty. Except for the clinical scores on day 3, no statistical differences for clinical and histopathologic scores between samples from the two treatment groups for a given day were identified. Use of lidocaine/prilocaine topical anesthetic cream was as effective as lidocaine infiltration in providing local anesthesia when performing episioplasty in mares. Its use decreased the need for twitching horses as well as the risk of deformation of the labia caused by lidocaine infiltration.
Peptide‐Based Instruction of Suppressor Commitment in Naïve T Cells and Dynamics of Immunosuppression in vivo
Authors: Von Boehmer H.
Published: June 2005

Recent years have witnessed the revival of suppressor T cells that control immunity by interfering with the generation of effector T‐cell function in vivo. The discovery that CD4 T cells with the CD25 surface marker were enriched in suppressor activity enabled further phenotypic and functional analysis of the so‐called natural suppressor cells. In vitro characterization showed that these cells were anergic, i.e. did not respond to antigenic stimulation with proliferation and, instead they suppressed other cells through direct cell contact resulting in inhibition of interleukin‐2 gene transcription. We have analysed the generation and function of suppressor T cells in T‐cell receptor (TCR) transgenic mice. The results showed that such cells can be generated intrathymically when agonist TCR ligands are expressed on thymic epithelial cells. Thus generated cells constitute a lineage of cells committed to suppression only with the ability to survive for prolonged periods of time in the absence of the inducing ligand. Because of appropriate homing receptors such cells can accumulate and proliferate in antigen draining lymphnodes after antigenic stimulation and suppress proliferation and cytokine secretion of CD4 and CD8 T cells as well as CD8 T‐cell‐mediated cytotoxicity. We also attempted to generate such cells from naïve T cells in secondary lymphoid tissue under conditions where expansion of already preformed suppressor T cells could be excluded. The results showed that subimmunogenic peptide delivery by osmotic minipumps or by peptide containing DEC 205 antibodies yielded CD25+ suppressor cells that were phenotypically and functionally indistinguishable from intrathymically generated suppressor cells. The experiments with DEC205 antibodies revealed (i) dose‐dependent proliferation of naïve T cells and (ii) conversion into suppressor T cells of only those T cells that underwent a limited number of cell divisions. These results are compatible with other studies that were, however, less rigorous in excluding expansion of existing cells as opposed to de novo generation of suppressor cells from naïve T cells. The fact that natural suppressor cells have an essential role in preventing autoimmunity and that they can be specifically induced by TCR agonist ligands opens new perspectives in preventing autoimmunity, transplant rejection and allergy.
Stromal Cells Attract B‐Cell Progenitors to Promote B‐Cell–B‐Cell Contact and Maturation
Authors: Milne C. D. , Zhang Y. , Paige C. J.
Published: June 2005

The in vitro differentiation of B‐lineage progenitors into Ig‐secreting mature B cells has classically required a co‐culture system containing lipopolysaccharide (LPS) and stromal cells. We have previously showed that B‐lineage progenitors cultured in round‐bottomed wells can mature and secrete immunoglobulin M (IgM) on par with cultures containing stromal cells. This clearly demonstrates that any factors essential for progenitor cell maturation can be found in cultures containing media, serum, LPS and B‐cell progenitors. However, stromal cells are important for the maturation observed when cells are cultured in flat‐bottomed wells. We hypothesized that stromal cells may attract B‐cell progenitors and promote contacts between responsive cells, a phenomenon that is mimicked by the cultures in round‐bottomed wells. In this study, we explore how stromal cells accomplish these functions. We show that stromal cells attract B‐cell progenitors in a pertussis toxin‐sensitive manner. The stromal cell line S17 produces the chemokine CXCL12, which is able to induce the chemotaxis of B‐lineage progenitors. Chemotaxis can be blocked by a small peptide inhibitor (T134) of CXCR4, the CXCL12 receptor. Further, disrupting chemotaxis can reduce the supportive role played by S17 when B‐lineage progenitors are cultured in flat‐bottomed wells.
Immunoadsorbent Assay Application for Studies of Protein Mixtures and Usage of Paper Carriers
Authors: Nezlin R.
Published: June 2005

Proteins immobilized on insoluble carriers or immunoadsorbents are now widely used in many areas of biological research. They are especially efficient in studies of complex protein mixtures because immunoadsorbents are very useful for isolation of individual components for further investigation. Antibodies immobilized on paper retain their specific activity and can be applied as very sensitive measurement tool.
From Clones of Cells to Cloned Genes and the Proteinpaedia
Authors: Kettman J. R.
Published: June 2005

This brief description follows the association of the author with Ivan Lefkovits from 1971 until this volume. Sketches of our mutual interests are included. Time periods in California, Basel and Texas are described. Decisions about preparing new tools for clonal analysis are elucidated, and experimental approaches leading to the x‐omic revolution are described.
Origin and Development of a Scientific Collaboration and a Long‐Lasting Friendship
Authors: Luzzati A. L.
Published: June 2005

The aim of this contribution is twofold: to honour Ivan Lefkovits with a short recollection of our scientific collaboration in the years 1972–1985 and a summary of our joint contribution to studies of the mechanisms and functions of the immune system and to acknowledge our long‐lasting friendship. Ivan's limiting dilution microculture method was adapted to rabbit peripheral blood lymphocytes (PBL). The antibody produced in the responding cultures was shown to be electrophoretically homogeneous and, in rabbits heterozygous at the b locus, to express either one or the other allele. Thus, the antibody released in single microcultures was indeed the product of single B‐cell clones and allelic exclusion, once achieved, was maintained throughout clonal proliferation. In the response to streptococcal polysaccharides, analysis of the clonotypes triggered in vitro provided information on mechanisms of clonal dominance. A two‐stage culture system was established, where rabbit PBL were precultured at low cell density with antigen before being partitioned in limiting dilution cultures. This method provided a new tool for studies of various cellular aspects of the immune response. Moreover, it allowed the application of the limiting dilution analysis to PBL from unprimed animals. Later, the method was extended with success to human PBL, leading to studies of regulatory aspects of immunity in this species.
Association between sharing of toothbrushes, eating and drinking habits and the presence of Actinobacillus actinomycetemcomitans in Moroccan adolescents
Authors: Haubek D. , Ismaili Z. , Poulsen S. , Ennibi O.‐K. , Benzarti N. , Baelum V.
Published: June 2005

Background/aims:  Actinobacillus actinomycetemcomitans is frequently detected in dental plaque collected from Moroccan adolescents, and has been shown to be associated with clinical attachment loss in this population. The aim of this study was to assess whether behaviors such as the sharing of toothbrushes, and eating and drinking habits were associated with the presence of A. actinomycetemcomitans in Moroccan adolescents.

Materials and methods:  A total of 121 adolescents were clinically examined. Interviews regarding sharing of toothbrushes, eating and drinking habits were performed, and plaque samples were collected and analyzed for A. actinomycetemcomitans with different leukotoxin promoter types by polymerase chain reaction. Based on eating and drinking habits, the study population was divided in a low risk behavior group (LRB) and a high risk behavior group (HRB).

Results:  No association was found between the sharing of toothbrushes and the presence of A. actinomycetemcomitans. The odds ratios between the HRB and LRB group for being positive for the JP2 type, for non‐JP2 types, and for any type of A. actinomycetemcomitans were 4.74 (95% CI 0.55; 40.71), 2.49 (95% CI 1.03; 5.97), and 2.97 (95% CI 1.28; 6.91), respectively. The difference in the mean number of teeth with a clinical attachment loss of ≥ 3 mm between the HRB and the LRB group was 0.91(95% CI 0.09; 1.72).

Conclusion:  Sharing of toothbrushes does not seem to be associated with the presence of A. actinomycetemcomitans in young Moroccans. Eating and drinking habits conducive to exchange of saliva are positively associated with presence of A. actinomycetemcomitans, and with a higher level of clinical attachment loss.
Porphyromonas gingivalis, Porphyromonas endodontalis, Prevotella intermedia and Prevotella nigrescens in endodontic lesions detected by culture and by PCR
Authors: Gomes B. P. F. A. , Jacinto R. C. , Pinheiro E. T. , Sousa E. L. R. , Zaia A. A. , Ferraz C. C. R. , Souza‐Filho F. J.
Published: June 2005

The aim of this study was to investigate the presence of four black‐pigmented bacteria, Porphyromonas gingivalis, Porphyromonas endodontalis, Prevotella intermedia and Prevotella nigrescens, in endodontic infections by culture and polymerase chain reaction (PCR) analyses. Microbial samples were obtained from 50 teeth with untreated necrotic pulps (primary infection) and from 50 teeth with failing endodontic treatment (secondary infection). Microbiological strict anaerobic techniques were used for serial dilution, plating, incubation, and identification. For PCR detection, the samples were analyzed using species‐specific primers of 16S rDNA and the downstream intergenic spacer region. Culture and PCR detected the test species in 13/100 and 50/100 of the study teeth, respectively. The organisms were cultured from 11/50 (22%) of primarily infected root canal samples and from 2/50 (4%) of secondary root canal samples. PCR detection identified the target species in 32/50 (64%) and 18/50 (36%) of primary and secondary infections, respectively. P. gingivalis was rarely isolated by culture methods (1%), but was the most frequently identified test species by PCR (38%). Similarly, P. endodontalis was not recovered by culture from any tooth studied, but was detected by PCR in 25% of the sampled teeth. PCR‐based identification also showed higher detection rates of P. intermedia (33%) and P. nigrescens (22%) than culture (13%). In conclusion, P. gingivalis, P. endodontalis, P. intermedia, and P. nigrescens were identified more frequently in teeth with necrotic pulp than in teeth with failing endodontic treatment. Also, a higher frequency of black‐pigmented species was detected by PCR than by culture.
Detection of periodontopathic bacteria and an oxidative stress marker in saliva from periodontitis patients
Authors: Sawamoto Y. , Sugano N. , Tanaka H. , Ito K.
Published: June 2005

We assessed the salivary levels of periodontopathic bacteria and 8‐hydroxydeoxyguanosine (8‐OHdG) in patients with periodontitis. The salivary levels of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Tannerella forsythia (formerly Bacteroides forsythus) were assessed using real‐time polymerase chain reaction. The 8‐OHdG levels were determined using an enzyme‐linked immunosorbent assay. The salivary levels of 8‐OHdG, P. gingivalis, and T. forsythia in the periodontitis patients were significantly higher than those in healthy subjects. By contrast, the A. actinomycetemcomitans level in healthy subjects was higher than that in periodontitis patients. 8‐OHdG was significantly correlated with P. gingivalis. Statistically significant decreases in the levels of P. gingivalis, probing depth, bleeding on probing, and 8‐OHdG were observed after initial periodontal treatment. These results suggest that the 8‐OHdG levels in saliva reflect the load of periodontal pathogens. 8‐OHdG could be a useful biomarker for assessing periodontal status accurately, and for evaluating the efficacy of periodontal treatment.
Antimicrobial effects of essential oils in combination with chlorhexidine digluconate
Authors: Filoche S. K. , Soma K. , Sissons C. H.
Published: June 2005

The aim of the present study was to compare antimicrobial effects of essential oils alone and in combination with chlorhexidine digluconate against planktonic and biofilm cultures of Streptococcus mutans and Lactobacillus plantarum. The essential oils included cinnamon, tea‐tree (Melaleuca alternifola), manuka (Leptospermum scoparium), Leptospermum morrisonii, arnica, eucalyptus, grapefruit, the essential oil mouthrinse Cool Mint Listerine® and two of its components, menthol and thymol. Cinnamon exhibited the greatest antimicrobial potency (1.25–2.5 mg/ml). Manuka, L. morrisonii, tea‐tree oils, and thymol also showed antimicrobial potency but to a lesser extent. The combination effect of the essential oil–chlorhexidine was greater against biofilm cultures of both S. mutans and L. plantarum than against planktonic cultures. The amount of chlorhexidine required to achieve an equivalent growth inhibition against the biofilm cultures was reduced 4–10‐fold in combination with cinnamon, manuka, L. morrisonii, thymol, and Listerine®. We conclude that there may be a role for essential oils in the development of novel anticaries treatments.
In vitro activity of a monoclonal killer anti‐idiotypic antibody and a synthetic killer peptide against oral isolates of Candida spp. differently susceptible to conventional antifungals
Authors: Manfredi M. , McCullough M. J. , Conti S. , Polonelli L. , Vescovi P. , Al‐karaawi Z. M. , Porter S. R.
Published: June 2005

Background/aims:  A monoclonal killer anti‐idiotypic antibody (mAbK10) and a synthetic killer peptide, acting as internal images of a microbicidal, wide‐spectrum yeast killer toxin (KT) have been recently shown to express candidacidal in vitro and an in vivo therapeutic activity against experimental mucosal and systemic candidosis models caused by a reference strain of Candida albicans (10S).

Material and methods:  The in vitro candidacidal activity of mAbK10 and synthetic killer peptide was compared using a colony forming unit assay against a large number of isolates of different Candida spp., obtained from oral saliva of adult diabetic (type 1 and 2) and nondiabetic subjects from Parma (Italy) and London (UK).

Results:  Both the KT‐mimics exerted a strong dose‐dependent candidacidal activity, probably mediated by the interaction with β‐glucan KT receptors on target yeast cells, against all the tested strains, regardless of their species and pattern of resistance to conventional antifungal agents.

Conclusions:  These observations open new perspectives in the design and production of candidacidal compounds whose mechanism reflects that exerted in nature by killer yeasts.
Microarrays complement culture methods for identification of bacteria in endodontic infections
Authors: Vianna M. E. , Horz H.‐P. , Gomes B. P. F. A. , Conrads G.
Published: June 2005

The aim of this study was to investigate the microbial composition of necrotic root canals using culture methods and microarray technology. Twenty uniradicular teeth with radiographic evidence of periapical bone loss and with no previous endodontic treatment were selected for this study. For molecular diagnosis a DNA chip with 20 different species‐specific, 16S‐rDNA‐directed catcher probes was used. The microorganisms most frequently detected by the DNA chip were: Micromonas micros, Fusobacterium nucleatum ssp., Tannerella forsythia, Treponema denticola, Veillonella parvula, Eubacterium nodatum, Porphyromonas gingivalis, Actinomyces odontolyticus, and Streptococcus constellatus. As expected, additional important bacterial taxa were found by culture analysis, but microorganisms such as T. forsythia and T. denticola could not be identified. In conclusion, microarrays may provide significant additional information regarding the endodontic microbiota by detecting bacterial species that are otherwise difficult or impossible to culture.
Antimicrobial susceptibility variation of 50 anaerobic periopathogens in aggressive periodontitis: an interindividual variability study
Authors: Lakhssassi N. , Elhajoui N. , Lodter J.‐P. , Pineill J.‐L. , Sixou M.
Published: June 2005

Background/aims:  The frequent use of antibiotics in developed countries has led to the emergence of widespread bacterial resistance. In this study, the interindividual variability of the antibiotic susceptibility of 50 putative microorganisms in aggressive periodontitis patients has been evaluated by means of VC (variation coefficient).

Material and methods:  A total of 60 microbial samples were collected from 20 adult patients diagnosed with aggressive periodontitis (2–4 samples by patient). Bacterial strains of Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia, Fusobacterium nucleatum, and Peptostreptococcus micros were isolated according to Slots' rapid identification method. The susceptibilities to 10 antibiotics were studied: penicillin G (PEN), ampicillin (AMP), amoxicillin (AMX), amoxicillin/clavulanate (AMC), tetracycline (TET), doxycycline (DOX), ciprofloxacin (CIP), erythromycin (ERY), spiramycin (SPI) and clindamycin (CLIN), using the Disk Diffusion Susceptibility test (DDS test: Kirby‐Bauer's modified method for anaerobic bacteria). The broth microdilution Minimum Inhibitory Concentration test was carried out as a control test.

Results:  Among the 50 identified bacteria, 15 were P. gingivalis, 12 P. intermedia, 8 T. forsythia, 9 F. nucleatum, and 6 P. micros. The results of the DDS test show that penicillins (especially AMC, AMP, and AMX), cyclines (especially DOX) and CLIN are highly effective against the 50 anaerobic studied bacteria. CIP and ERY have the lowest efficacy against those bacteria. CIP shows a very variable activity according to anaerobic bacteria species, being particularly inactive against P. gingivalis and very efficient against T. forsythia and P. micros. SPI is also highly efficient but not against P. micros.

Conclusions:  The interindividual susceptibility of principal periodontal pathogens to antibiotics is not homogeneous and seems to vary according to bacterial species and antimicrobial molecules. This variability seems to be greater with older molecules (PEN, TET, ERY) than with more recent ones, which indicates more stable results (AMC, AMX, AMP, and DOX). P. intermedia appeared to be the bacteria most resistant to penicillins and showed the highest coefficient variation. Together with scaling and root planing, the combination of two antibiotics would therefore seem to be recommended in the treatment of aggressive periodontitis, particularly in the presence of P. intermedia.
No evidence of in vitro and in vivo porcine endogenous retrovirus infection after plasmapheresis through the AMC‐bioartificial liver
Authors: Di Nicuolo Giuseppe , van de Kerkhove Maarten‐Paul , Hoekstra Ruurdtje , Beld Marcel G. H. M. , Amoroso Pietro , Battisti Sonia , Starace Maria , Florio Ernesto di , Scuderi Vincenzo , Scala Simona , Bracco Adele , Mancini Antonio , Chamuleau Robert A. F. M. , Calise Fulvio
Published: June 2005

Abstract:  Background:  Currently a number of bioartificial livers (BAL) based on porcine liver cells have been developed as a treatment to bridge acute liver failure patients to orthotopic liver transplantation or liver regeneration. These xenotransplantation related treatments hold the risk of infection of treated patients by porcine endogenous retrovirus (PERV) released from the porcine cells, as in vitro infection experiments and transplantations in immunocompromised mice have shown that PERV is able to infect human cells. The Academic Medical Center (AMC)‐BAL, unlike other BALs, is characterized by direct contact between porcine liver cells and human plasma, and might therefore be permissive for PERV transfer.

Methods:  Prior to a clinical phase I trial, human plasma perfused through the AMC‐BAL was investigated for PERV DNA and RNA. Moreover productive infectivity was analyzed by exposing the plasma to HEK‐293 cells that were subsequently tested for PERV DNA, PERV RNA and reverse transcriptase activity.

Results:  Although PERV DNA was detected in the perfused plasma, no productive infectivity was detected. Consequently fourteen patients were treated with the AMC‐BAL and monitored for PERV transmission. Immediately after treatment the plasma of the patients was positive for PERV DNA, most probably due to porcine liver cell lysis. The PERV DNA was cleared within 2 weeks post‐treatment and no PERV RNA was detected. No productive infectivity in human embryonic kidney (HEK)‐293 cells exposed to plasma of treated patients was detectable.

Conclusion:  To conclude, no release of infective PERV particles from the AMC‐BAL was observed. Therefore we consider the AMC‐BAL as safe, however careful surveillance of patients will be continued.
Single nucleotide polymorphisms of the prion protein gene (PRNP) in Chinese pig breeds
Authors: Meng Liping , Zhao Deming , Liu Hongxiang , Yang Jianmin , Ning Zhangyong
Published: June 2005

Abstract:  Prion diseases (transmissible spongiform encephalopathies, TSE), as a group of fatal neurodegenerative diseases, have affected humans and a variety of other mammals. Although no natural TSE have been documented in pigs, appropriate precautions need to be taken to prevent the iatrogenic spread of prion disease through pig‐to‐human xenotransplantation. Polymorphisms within the open reading frame (ORF) of the single‐copy gene of prion protein (PRNP) are associated with susceptibility to scrapie in sheep and variant Creutzfeldt‐Jacob disease in humans. We screened polymorphisms in the PRNP gene of 64 China Experimental Minipigs and Beijing Large White pigs. Our findings suggest that the porcine PRNP gene is highly homogenous. The amino acid sequences of the mature prion protein of all samples tested were identical. Four single nucleotide polymorphisms (G11A, G615C, G684A, T726G) in the ORF of the porcine PRNP gene were found, and the G→C nucleotide substitution resulted in a serine to asparaginate amino acid substitution at codon 4. We conclude that pigs raised under specific pathogen‐free conditions, with the exclusion of rendered mammalian material for at least two generations, will have little risk of being infected with a TSE, and even less possibility of transmitting prion disease to humans through xenotransplantation.
Characterization of the swine major histocompatibility complex alleles at eight loci in Westran pigs
Authors: Lee Jun‐Heon , Simond Denbigh , Hawthorne Wayne J. , Walters Stacey N. , Patel Anita T. , Smith Douglas M. , O'Connell Phillip J. , Moran Chris
Published: June 2005

Abstract:  Background:  Pigs are an important large animal model for transplantation and a potential source of xenografts. Swine leukocyte antigen (SLA) molecules are strong mediators of alloreactive and xenoreactive immune responses. We have characterized the SLA alleles of a new pig line bred for transplantation research, the Westran (Westmead Hospital transplantation) pig, described in a companion paper.

Methods:  Three sixth generation inbred Westran pigs and a Large White pig control were used to assess SLA alleles. We examined the SLA‐1, SLA‐3, SLA‐6, SLA‐2, DQA1, DQB1, DRA1 and DRB1 loci using reverse transcription‐polymerase chain reaction and sequencing‐based method.

Results:  All of the Westran pigs had a single allele at each locus, except for the SLA‐1 locus. Typing of the SLA‐1 locus in additional animals indicated that this is most likely the result of a duplication of the SLA‐1 locus rather than heterozygosity. The lack of SLA heterozygosity is consistent with the previous finding of low microsatellite marker heterozygosity and is the result of both the recent deliberate inbreeding of these pigs and their derivation from a feral stock from Kangaroo Island, South Australia, established by the release of a single pair in 1803.

Conclusions:  After comparing DNA and protein sequences of the Westran SLA alleles with published GenBank SLA sequences, the SLA class I alleles found in the Westran pigs were all novel, while the SLA‐DR and DQB1 alleles have been previously described in other pig breeds. Characterization of the SLA alleles in the Westran pigs has identified novel alleles and will be useful for designing protocols for modulation of immune responses to allografts and xenografts.