The limits of mtDNA analysis for determining the provenance of invasive species: a midwife toad example

For most if not all European herpetofauna, range-wide mtDNA phylogeographies have been published. This facilitates establishing the provenance of introduced populations. However, precision is contingent on the spatial genetic structure across the range of the taxon under study and, in particular, from where within that range the introduction was sourced. In the Netherlands, the common midwife toad, Alytes obstetricans, only naturally occurs in the extreme southeast and is on the decline there. Yet, introduced populations thrive elsewhere in the country. We use mtDNA analysis to try to determine the origin of two introduced populations along the Dutch coast, in the city of The Hague and the dune area Meijendel. We compiled a database of hundreds of individuals from throughout the distribution range and added over 130 individuals from both native and introduced populations from the Netherlands, Belgium and Germany. The mtDNA haplotypes found in the introduced populations are associated with postglacial expansion. The main haplotype predominates in the natural range in the Netherlands, but also occurs much more widely across western Europe, north of the Pyrenees. A closely related haplotype, newly identified from The Hague, was not found in the native Netherlands range, suggesting an origin from abroad. The combination of low phylogeographic resolution and low sampling density in the postglacially colonized part of the range hampers our ability to determine the provenance of the introduced A. obstetricans populations.

The introduction of three cryptic tree frog species in the Dutch coastal dunes challenges conservation paradigms

Invasive species are considered one of the main drivers of the sixth mass extinction. Conservation solutions depend on whether a species is also indigenous to the country it invades (i.e., beyond its native range). In the case of invasive cryptic species, genetic tools are required to establish their identity. We illustrate these issues with the human-mediated colonization of the Dutch coastal dunes by Hyla tree frogs. Although previously assumed to concern the indigenous common tree frog H. arborea, European tree frogs comprise a complex of allopatric cryptic species, meaning the taxonomic identity of introduced Dutch populations warrants investigation. We sequence mtDNA for 173 individuals from native and introduced populations across the Netherlands and compare our dataset with hundreds of Hyla haplotypes previously barcoded in the Western Palearctic. Two of the dune populations carry an mtDNA haplotype of the native species H. arborea that occurs naturally elsewhere in the Netherlands. In contrast, mtDNA assigned to the eastern tree frog H. orientalis was detected in all three other dune populations. In one of these populations mtDNA of the Italian tree frog H. intermedia was also found. Not one, but three species of tree frogs have thus been introduced to the Dutch coastal dunes, only one of them being native to the Netherlands. This situation causes a conservation conundrum as some introduced populations are lawfully protected but could pose a threat to local biodiversity. Regarding the ‘true’ exotic tree frog species, all conservation options should be considered.

Campylobacter pinnipediorum subsp. caledonicus and C. pinnipediorum subsp. pinnipediorum recovered from abscesses in pinnipeds

Campylobacter pinnipediorum was described recently for isolates recovered from pinnipeds. The novel species was further split into 2 subspecies based on host and geography, with C. pinnipediorum subsp. pinnipediorum recovered from otariid seals in California (USA) and C. pinnipediorum subsp. caledonicus recovered from phocid seals in Scotland. We report details of the infections of 7 pinnipeds from which C. pinnipediorum was isolated: C. pinnipediorum subsp. caledonicus was isolated from 2 harbour seals Phoca vitulina and a single grey seal Halichoerus grypus, and C. pinnipediorum subsp. pinnipediorum was isolated from California sea lions Zalophus californianus. Six of the isolates were recovered from samples collected at post-mortem investigation. In 2 of the Scottish seals and in 3 of the California seals, C. pinnipediorum was the sole bacterial isolate recovered from abscesses present and suggests they may have resulted from conspecific or intraspecific bite wounds.

After the bite: bacterial transmission from grey seals (Halichoerus grypus) to harbour porpoises (Phocoena phocoena)

Recent population growth of the harbour porpoise (Phocoena phocoena), grey seal (Halichoerus grypus) and common seal (Phoca vitulina) in the North Sea has increased potential interaction between these species. Grey seals are known to attack harbour porpoises. Some harbour porpoises survive initially, but succumb eventually, often showing severely infected skin lesions. Bacteria transferred from the grey seal oral cavity may be involved in these infections and eventual death of the animal. In humans, seal bites are known to cause severe infections. In this study, a 16S rRNA-based microbiome sequencing approach is used to identify the oral bacterial diversity in harbour porpoises, grey seals and common seals; detect the potential transfer of bacteria from grey seals to harbour porpoises by biting and provide insights in the bacteria with zoonotic potential present in the seal oral cavity. β-diversity analysis showed that 12.9% (4/31) of the harbour porpoise skin lesion microbiomes resembled seal oral microbiomes, while most of the other skin lesion microbiomes also showed seal-associated bacterial species, including potential pathogens. In conclusion, this study shows that bacterial transmission from grey seals to harbour porpoises by biting is highly likely and that seal oral cavities harbour many bacterial pathogens with zoonotic potential.

Forensic microbiology reveals that Neisseria animaloris infections in harbour porpoises follow traumatic injuries by grey seals

Neisseria animaloris is considered to be a commensal of the canine and feline oral cavities. It is able to cause systemic infections in animals as well as humans, usually after a biting trauma has occurred. We recovered N. animaloris from chronically inflamed bite wounds on pectoral fins and tailstocks, from lungs and other internal organs of eight harbour porpoises. Gross and histopathological evidence suggest that fatal disseminated N. animaloris infections had occurred due to traumatic injury from grey seals. We therefore conclude that these porpoises survived a grey seal predatory attack, with the bite lesions representing the subsequent portal of entry for bacteria to infect the animals causing abscesses in multiple tissues, and eventually death. We demonstrate that forensic microbiology provides a useful tool for linking a perpetrator to its victim. Moreover, N. animaloris should be added to the list of potential zoonotic bacteria following interactions with seals, as the finding of systemic transfer to the lungs and other tissues of the harbour porpoises may suggest a potential to do likewise in humans.

Living in Cold Blood: Arcobacter, Campylobacter, and Helicobacter in Reptiles

Species of the Epsilonproteobacteria genera Arcobacter, Campylobacter, and Helicobacter are commonly associated with vertebrate hosts and some are considered significant pathogens. Vertebrate-associated Epsilonproteobacteria are often considered to be largely confined to endothermic mammals and birds. Recent studies have shown that ectothermic reptiles display a distinct and largely unique Epsilonproteobacteria community, including taxa which can cause disease in humans. Several Arcobacter taxa are widespread amongst reptiles and often show a broad host range. Reptiles carry a large diversity of unique and novel Helicobacter taxa, which apparently evolved in an ectothermic host. Some species, such as Campylobacter fetus, display a distinct intraspecies host dichotomy, with genetically divergent lineages occurring either in mammals or reptiles. These taxa can provide valuable insights in host adaptation and co-evolution between symbiont and host. Here, we present an overview of the biodiversity, ecology, epidemiology, and evolution of reptile-associated Epsilonproteobacteria from a broader vertebrate host perspective.

Mitigating Batrachochytrium salamandrivorans in Europe

The infectious chytrid fungus Batrachochytrium salamandrivorans (Bsal) has been responsible for severe population declines of salamander populations in Europe. Serious population declines and loss of urodelan diversity may occur if appropriate action is not taken to mitigate against the further spread and impact of Bsal. We provide an overview of several potential mitigation methods, and describe their possible advantages and limitations. We conclude that long-term, context-dependent, multi-faceted approaches are needed to successfully mitigate adverse effects of Bsal, and that these approaches should be initiated pre-arrival of the pathogen. The establishment of ex situ assurance colonies, or management units, for species threatened with extinction, should be considered as soon as possible. While ex situ conservation and preventive measures aimed at improving biosecurity by limiting amphibian trade may be implemented quickly, major challenges that lie ahead are in designing in situ disease containment and mitigation post-arrival and in increasing public awareness.

Homologous Recombination between Genetically Divergent Campylobacter fetus Lineages Supports Host-Associated Speciation

Homologous recombination is a major driver of bacterial speciation. Genetic divergence and host association are important factors influencing homologous recombination. Here, we study these factors for Campylobacter fetus, which shows a distinct intraspecific host dichotomy. Campylobacter fetus subspecies fetus (Cff) and venerealis are associated with mammals, whereas C. fetus subsp. testudinum (Cft) is associated with reptiles. Recombination between these genetically divergent C. fetus lineages is extremely rare. Previously it was impossible to show whether this barrier to recombination was determined by the differential host preferences, by the genetic divergence between both lineages or by other factors influencing recombination, such as restriction-modification, CRISPR/Cas, and transformation systems. Fortuitously, a distinct C. fetus lineage (ST69) was found, which was highly related to mammal-associated C. fetus, yet isolated from a chelonian. The whole genome sequences of two C. fetus ST69 isolates were compared with those of mammal- and reptile-associated C. fetus strains for phylogenetic and recombination analysis. In total, 5.1–5.5% of the core genome of both ST69 isolates showed signs of recombination. Of the predicted recombination regions, 80.4% were most closely related to Cft, 14.3% to Cff, and 5.6% to C. iguaniorum. Recombination from C. fetus ST69 to Cft was also detected, but to a lesser extent and only in chelonian-associated Cft strains. This study shows that despite substantial genetic divergence no absolute barrier to homologous recombination exists between two distinct C. fetus lineages when occurring in the same host type, which provides valuable insights in bacterial speciation and evolution.

Campylobacter blaseri sp. nov., isolated from common seals (Phoca vitulina)

During a study to assess the faecal microbiome of common seals (Phoca vitulina) in a Dutch seal rehabilitation centre, 16S rRNA gene sequences of an unknown Campylobacter taxon were identified. Campylobacter isolates, which differed from the established Campylobacter taxa, were cultured and their taxonomic position was determined by a polyphasic study based on ten isolates. The isolates were characterized by 16S rRNA and atpA gene sequence analyses and by conventional phenotypic testing. Based on the whole genome sequences, the average nucleotide identity and core genome phylogeny were determined. The isolates formed a separate phylogenetic clade, divergent from all other Campylobacter taxa and most closely related to Campylobacter corcagiensis, Campylobacter geochelonis and Campylobacter ureolyticus. The isolates can be distinguished phenotypically from all other Campylobacter taxa based on their lack of motility, growth at 25 °C and growth on MacConkey agar. This study shows that these isolates represent a novel species within the genus Campylobacter, for which the name Campylobacter blaseri sp. nov. is proposed. The type strain for this novel species is 17S00004-5^T (=LMG 30333^T=CCUG 71276^T).

Whole genome-based phylogeny of reptile-associated Helicobacter indicates independent niche adaptation followed by diversification in a poikilothermic host

Reptiles have been shown to host a significant Helicobacter diversity. In order to survive, reptile-associated Helicobacter lineages need to be adapted to the thermally dynamic environment encountered in a poikilothermic host. The whole genomes of reptile-associated Helicobacter lineages can provide insights in Helicobacter host adaptation and coevolution. These aspects were explored by comparing the genomes of reptile-, bird-, and mammal-associated Helicobacter lineages. Based on average nucleotide identity, all reptile-associated Helicobacter lineages in this study could be considered distinct species. A whole genome-based phylogeny showed two distinct clades, one associated with chelonians and one associated with lizards. The phylogeny indicates initial adaptation to an anatomical niche, which is followed by an ancient host jump and subsequent diversification. Furthermore, the ability to grow at low temperatures, which might reflect thermal adaptation to a reptilian host, originated at least twice in Helicobacter evolution. A putative tricarballylate catabolism locus was specifically present in Campylobacter and Helicobacter isolates from reptiles. The phylogeny of reptile-associated Helicobacter parallels host association, indicating a high level of host specificity. The high diversity and deep branching within these clades supports long-term coevolution with, and extensive radiation within the respective reptilian host type.

Campylobacter pinnipediorum sp. nov., isolated from pinnipeds, comprising Campylobacter pinnipediorum subsp. pinnipediorum subsp. nov. and Campylobacter pinnipediorum subsp. caledonicus subsp. nov

During independent diagnostic screenings of otariid seals in California (USA) and phocid seals in Scotland (UK), Campylobacter-like isolates, which differed from the established taxa of the genus Campylobacter, were cultured from abscesses and internal organs of different seal species. A polyphasic study was undertaken to determine the taxonomic position of these six isolates. The isolates were characterized by 16S rRNA gene and AtpA sequence analysis and by conventional phenotypic testing. The whole-genome sequences were determined for all isolates, and the average nucleotide identity (ANI) was determined. The isolates formed a separate phylogenetic clade, divergent from all other taxa of the genus Campylobacter and most closely related to Campylobactermucosalis. Although all isolates showed 100 % 16S rRNA gene sequence homology, AtpA and ANI analyses indicated divergence between the otariid isolates from California and the phocid isolates from Scotland, which warrants subspecies status for each clade. The two subspecies could also be distinguished phenotypically on the basis of catalase activity. This study shows clearly that the isolates obtained from pinnipeds represent a novel species within the genus Campylobacter, for which the name Campylobacter pinnipediorum sp. nov. is proposed. Within this novel species, the Californian isolates represent a separate subspecies, for which the name C. pinnipediorum subsp. pinnipediorum subsp. nov. is proposed. The type strain for both this novel species and subspecies is RM17260T (=LMG 29472T=CCUG 69570T). The Scottish isolates represent another subspecies, for which the name C. pinnipediorum subsp. caledonicus subsp. nov. is proposed. The type strain of this subspecies is M302/10/6T (=LMG 29473T=CCUG 68650T).

Comparative Genomics of Campylobacter iguaniorum to Unravel Genetic Regions Associated with Reptilian Hosts

Campylobacter iguaniorum is most closely related to the species C. fetus, C. hyointestinalis, and C. lanienae. Reptiles, chelonians and lizards in particular, appear to be a primary reservoir of this Campylobacter species. Here we report the genome comparison of C. iguaniorum strain 1485E, isolated from a bearded dragon (Pogona vitticeps), and strain 2463D, isolated from a green iguana (Iguana iguana), with the genomes of closely related taxa, in particular with reptile-associated C. fetus subsp. testudinum. In contrast to C. fetus, C. iguaniorum is lacking an S-layer encoding region. Furthermore, a defined lipooligosaccharide biosynthesis locus, encoding multiple glycosyltransferases and bounded by waa genes, is absent from C. iguaniorum. Instead, multiple predicted glycosylation regions were identified in C. iguaniorum. One of these regions is > 50 kb with deviant G + C content, suggesting acquisition via lateral transfer. These similar, but non-homologous glycosylation regions were located at the same position on the genome in both strains. Multiple genes encoding respiratory enzymes not identified to date within the C. fetus clade were present. C. iguaniorum shared highest homology with C. hyointestinalis and C. fetus. As in reptile-associated C. fetus subsp. testudinum, a putative tricarballylate catabolism locus was identified. However, despite colonizing a shared host, no recent recombination between both taxa was detected. This genomic study provides a better understanding of host adaptation, virulence, phylogeny, and evolution of C. iguaniorum and related Campylobacter taxa.

Comparative Genomics of Campylobacter fetus from Reptiles and Mammals Reveals Divergent Evolution in Host-Associated Lineages

Campylobacter fetus currently comprises three recognized subspecies, which display distinct host association. Campylobacter fetus subsp. fetus and C fetus subsp. venerealis are both associated with endothermic mammals, primarily ruminants, whereas C fetus subsp. testudinum is primarily associated with ectothermic reptiles. Both C. fetus subsp. testudinum and C. fetus subsp. fetus have been associated with severe infections, often with a systemic component, in immunocompromised humans. To study the genetic factors associated with the distinct host dichotomy in C. fetus, whole-genome sequencing and comparison of mammal- and reptile-associated C fetus was performed. The genomes of C fetus subsp. testudinum isolated from either reptiles or humans were compared with elucidate the genetic factors associated with pathogenicity in humans. Genomic comparisons showed conservation of gene content and organization among C fetus subspecies, but a clear distinction between mammal- and reptile-associated C fetus was observed. Several genomic regions appeared to be subspecies specific, including a putative tricarballylate catabolism pathway, exclusively present in C fetus subsp. testudinum strains. Within C fetus subsp. testudinum, sapA, sapB, and sapAB type strains were observed. The recombinant locus iamABC (mlaFED) was exclusively associated with invasive C fetus subsp. testudinum strains isolated from humans. A phylogenetic reconstruction was consistent with divergent evolution in host-associated strains and the existence of a barrier to lateral gene transfer between mammal- and reptile-associated C fetus Overall, this study shows that reptile-associated C fetus subsp. testudinum is genetically divergent from mammal-associated C fetus subspecies.

Campylobacter iguaniorum sp. nov., isolated from reptiles

During sampling of reptiles for members of the class Epsilonproteobacteria, strains representing a member of the genus Campylobacter not belonging to any of the established taxa were isolated from lizards and chelonians. Initial amplified fragment length polymorphism, PCR and 16S rRNA sequence analysis showed that these strains were most closely related to Campylobacter fetus and Campylobacter hyointestinalis. A polyphasic study was undertaken to determine the taxonomic position of five strains. The strains were characterized by 16S rRNA and atpA sequence analysis, matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry and conventional phenotypic testing. Whole-genome sequences were determined for strains 1485E(T) and 2463D, and the average nucleotide and amino acid identities were determined for these strains. The strains formed a robust phylogenetic clade, divergent from all other species of the genus Campylobacter. In contrast to most currently known members of the genus Campylobacter, the strains showed growth at ambient temperatures, which might be an adaptation to their reptilian hosts. The results of this study clearly show that these strains isolated from reptiles represent a novel species within the genus Campylobacter, for which the name Campylobacter iguaniorum sp. nov. is proposed. The type strain is 1485E(T) ( = LMG 28143(T) = CCUG 66346(T)).

Campylobacter fetus subsp. testudinum subsp. nov., isolated from humans and reptiles

A polyphasic study was undertaken to determine the taxonomic position of 13 Campylobacter fetus -like strains from humans (n = 8) and reptiles (n = 5). The results of matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) MS and genomic data from sap analysis, 16S rRNA gene and hsp60 sequence comparison, pulsed-field gel electrophoresis, amplified fragment length polymorphism analysis, DNA–DNA hybridization and whole genome sequencing demonstrated that these strains are closely related to C. fetus but clearly differentiated from recognized subspecies of C. fetus . Therefore, this unique cluster of 13 strains represents a novel subspecies within the species C. fetus , for which the name Campylobacter fetus subsp. testudinum subsp. nov. is proposed, with strain 03-427T ( = ATCC BAA-2539T = LMG 27499T) as the type strain. Although this novel taxon could not be differentiated from C. fetus subsp. fetus and C. fetus subsp. venerealis using conventional phenotypic tests, MALDI-TOF MS revealed the presence of multiple phenotypic biomarkers which distinguish Campylobacter fetus subsp. testudinum subsp. nov. from recognized subspecies of C. fetus .

Occurrence, diversity, and host association of intestinal Campylobacter, Arcobacter, and Helicobacter in reptiles

Campylobacter, Arcobacter, and Helicobacter species have been isolated from many vertebrate hosts, including birds, mammals, and reptiles. Multiple studies have focused on the prevalence of these Epsilonproteobacteria genera in avian and mammalian species. However, little focus has been given to the presence within reptiles, and their potential zoonotic and pathogenic roles. In this study, occurrence, diversity, and host association of intestinal Epsilonproteobacteria were determined for a large variety of reptiles. From 2011 to 2013, 444 cloacal swabs and fecal samples originating from 417 predominantly captive-held reptiles were screened for Epsilonproteobacteria. Campylobacter, Arcobacter, and Helicobacter genus specific PCRs were performed directly on all samples. All samples were also cultured on selective media and screened for the presence of Epsilonproteobacteria. Using a tiered approach of AFLP, atpA, and 16S rRNA sequencing, 432 Epsilonproteobacteria isolates were characterized at the species level. Based on PCR, Campylobacter, Arcobacter, and Helicobacter were detected in 69.3% of the reptiles; 82.5% of the chelonians, 63.8% of the lizards, and 58.0% of the snakes were positive for one or more of these genera. Epsilonproteobacteria were isolated from 22.1% of the reptiles and were isolated most frequently from chelonians (37.0%), followed by lizards (19.6%) and snakes (3.0%). The most commonly isolated taxa were Arcobacter butzleri, Arcobacter skirrowii, reptile-associated Campylobacter fetus subsp. testudinum, and a putative novel Campylobacter taxon. Furthermore, a clade of seven related putative novel Helicobacter taxa was isolated from lizards and chelonians. This study shows that reptiles carry various intestinal Epsilonproteobacteria taxa, including several putative novel taxa.

Human infections with new subspecies of Campylobacter fetus

Campylobacter fetus subsp. testudinum subsp. nov. is a newly proposed subspecies of C. fetus with markers of reptile origin. We summarize epidemiologic information for 9 humans infected with this bacterium. All cases were in men, most of whom were of Asian origin. Infection might have been related to exposure to Asian foods or reptiles.

Interlayer transport in disordered semiconductor electron bilayers

We study the effects of disorder on the interlayer transport properties of disordered semiconductor bilayers by performing self-consistent quantum transport calculations. We find that the addition of material disorder to the system affects the interlayer interactions leading to significant deviations in the interlayer transfer characteristics. In particular, we find that disorder decreases and broadens the tunneling peak, effectively reducing the interacting system to a non-interacting system. Our results suggest that the experimental observation of exchange-enhanced interlayer transport in semiconductor bilayers requires materials with mean free paths larger than the spatial extent of the system.

Livestock-associated MRSA ST398 carriage in pig slaughterhouse workers related to quantitative environmental exposure

OBJECTIVES

To assess livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) carriage among workers in pig slaughterhouses and assess associated risk factors, including occupational exposure to LA-MRSA.

METHODS

A cross-sectional study in three Dutch pig slaughterhouses was undertaken. Nasal swabs of participants were taken. Nasal swabs and surface wipes, air and glove samples were screened for presence of methicillin-resistant Staphylococcus aureus (MRSA). MRSA was quantitatively determined on gloves and in air samples by culturing and real-time PCR.

RESULTS

11 of 341 (3.2%) participants were identified as nasal MRSA carriers. MRSA-positive workers were predominantly found at the start of the slaughter process. Major risk factors for carriage were working in the lairage and working in the scalding and dehairing area. Most nasal isolates (73%) belonged to the LA-MRSA clone ST398. MRSA ST398-positive environmental samples were found throughout the slaughter process. A clear decrease was seen along the slaughterline in the number of MRSA-positive samples and in the MRSA amount per sample.

CONCLUSIONS

This study showed that working in the lairage area or scalding and dehairing area were the major risk factors for MRSA carriage in pig slaughterhouse workers, while the overall prevalence of MRSA carriage is low. Occupational exposure to MRSA decreased along the slaughterline, and the risk of carriage showed a parallel decrease.

The effect of disorder in superfluid double layer graphene

We investigate the superfluid properties of disordered double layer graphene systems using the non-equilibrium Green's function formalism. The complexity of such a structure makes it imperative to study the effects of lattice vacancies which will inevitably arise during fabrication. We present and compare room temperature performance characteristics for both ideal and disordered double layer graphene systems in an effort to illustrate the behavior of a Bose-Einstein condensate in the presence of lattice defects under non-equilibrium conditions. We find that lattice vacancies spread throughout the top layer past the coherence length have a reduced effect compared to the ideal case. However, vacancies concentrated near the metal contacts within the coherence length significantly alter the interlayer superfluid transport properties.

A path integral study of the role of correlation in exchange coupling of spins in double quantum dots and optical lattices

We explore exchange coupling of a pair of spins in a double dot and in an optical lattice, using the frequency of exchanges in a bosonic path integral, evaluated using Monte Carlo simulation. The algorithm gives insights into the role of correlation through visualization of two-particle probability densities, instantons, and the correlation hole. We map the problem to the Hubbard model and see that exchange and correlation renormalize the model parameters, dramatically reducing the effective on-site repulsion at larger separations.

A randomized, placebo-controlled trial of granulocyte-macrophage colony-stimulating factor and nucleoside analogue therapy in AIDS

Preliminary preclinical and clinical data suggest that granulocyte-macrophage colony-stimulating factor (GM-CSF) may decrease viral replication. Therefore, 105 individuals with AIDS who were receiving nucleoside analogue therapy were enrolled in a placebo-controlled, double-blind study and were randomized to receive either 125 microgram/m(2) of yeast-derived, GM-CSF (sargramostim) or placebo subcutaneously twice weekly for 6 months. Subjects were evaluated for toxicity and disease progression. A significant decrease in mean virus load (VL) was observed for the GM-CSF treatment group at 6 months (-0.07 log(10) vs. -0.60 log(10); P=.02). More subjects achieved human immunodeficiency virus (HIV)-RNA levels <500 copies/mL at >/=2 evaluations (2% on placebo vs. 11% on GM-CSF; P=.04). Genotypic analysis of 46 subjects demonstrated a lower frequency of zidovudine-resistant mutations among those receiving GM-CSF (80% vs. 50%; P=.04). No difference was observed in the incidence of opportunistic infections (OIs) through 6 months or survival, despite a higher risk for OI among GM-CSF recipients. GM-CSF reduced VL and limited the evolution of zidovudine-resistant genotypes, potentially providing adjunctive therapy in HIV disease.

Phase III study of granulocyte-macrophage colony-stimulating factor in advanced HIV disease: effect on infections, CD4 cell counts and HIV suppression. Leukine/HIV Study Group

OBJECTIVE

To evaluate the effect of adjuvant granulocyte-macrophage colony-stimulating factor (GM-CSF) (sargramostim, yeast-derived recombinant human GM-CSF) on incidence and time to opportunistic infection or death, plasma HIV-RNA, and CD4 cell count in patients with advanced HIV disease.

METHODS

This Phase III randomized, double-blind, placebo-controlled trial enrolled subjects with CD4 cell counts < or = 50 x 10(6)/l or < or = 100 x 10(6)/l with a prior AIDS-defining illness on stable antiretroviral therapy. Subjects were stratified by baseline HIV-RNA level (> or = or < 30,000 copies/ml) and randomized to receive subcutaneous injections of GM-CSF 250 microg or placebo three times per week for 24 weeks. Subjects were permitted to continue on blinded drug for up to 20 months. Subjects were evaluated for infections, plasma HIV-RNA, lymphocyte counts, changes in antiretroviral therapy, toxicity, and survival.

RESULTS

Three-hundred and nine subjects received at least one dose of study drug, 70% completed 24 weeks of therapy. Groups were well matched at baseline. Significant increases in CD4 cell and neutrophil counts were observed at 1, 3, and 6 months in the GM-CSF group. GM-CSF significantly reduced the incidence of overall infections (78% placebo versus 67% GM-CSF; P = 0.03) and delayed time to first infection (56 days placebo versus 97 days GM-CSF; P = 0.04). No statistical difference in cumulative opportunistic infections was observed between groups; however, among subjects without an opportunistic infection prior to study, the GM-CSF group demonstrated a trend towards fewer subjects with an opportunistic infection on study (26% placebo versus 8% GM-CSF; P = 0.08). Change in HIV-RNA was not significantly different between groups, but significantly fewer GM-CSF subjects with baseline viral load < 30,000 copies/ml had changes in antiretroviral therapy for increased viral load (42% placebo versus 21% GM-CSF; P = 0.01). In patients with HIV-RNA levels below the limit of detection at baseline, more GM-CSF patients maintained an undetectable viral load at 24 weeks (54% placebo versus 83% GM-CSF; P = 0.02). GM-CSF was well tolerated.

CONCLUSIONS

GM-CSF significantly increased CD4 cell count and decreased virological breakthrough and overall infection rate in subjects with advanced HIV disease.

The safety and efficacy of granulocyte-macrophage colony-stimulating factor (Sargramostim) added to indinavir- or ritonavir-based antiretroviral therapy: a randomized double-blind, placebo-controlled trial

Sargramostim is a yeast-derived, recombinant human granulocyte-macrophage colony-stimulating factor with therapeutic potential in human immunodeficiency virus (HIV) infection. Its safety and activity when used in combination with protease inhibitors were evaluated in a randomized, double-blind trial in which 20 HIV-infected subjects on stable antiretroviral regimens, including indinavir or ritonavir, received sargramostim or placebo 3 times a week for 8 weeks. Analysis of HIV virus load excluded any 0. 5 log10 increase due to sargramostim (95% confidence interval, -0.68 to 0.44). Sargramostim was well tolerated, and inflammatory cytokines and surrogate markers of disease progression, such as serum levels of interleukin-10 and soluble tumor necrosis factor receptors types Iota and IotaIota, remained stable in subjects receiving sargramostim. Sargramostim treatment was associated with a trend toward decreased HIV RNA (>0.5 log10) and increased CD4+ cell count (>30%). These results became statistically significant only when subjects with baseline virus loads within the limits of detection or baseline CD4 cell count >50 were analyzed. No difference in indinavir pharmacokinetics was observed before or after sargramostim therapy.

Combination therapy with a CD4-CDR3 peptide analog and cyclosporin A to prevent graft-vs-host disease in a MHC-haploidentical bone marrow transplantation model

Graft-versus-host disease (GVHD) is a major complication associated with allogeneic bone marrow transplantation (BMT). Cyclosporin A (CsA) has been used as the basis for most immunosuppressive regimens for the prevention of GVHD, but has exhibited only limited effects and is hampered by nephrotoxicity, neurotoxicity, and hepatotoxicity. Previously, we showed that rD-mPGPtide, a structure-base designed peptide analog of the CDR3-like region of domain 1 of the murine CD4 molecule, suppressed the development of GVHD in a MHC-haploidentical murine BMT model when administered early in the course of disease. This peptide analog also inhibited T cell proliferation in mixed lymphocyte reactions (MLR) in vitro. The current results demonstrate that CsA and rD-mPGPtide exhibit an additive inhibitory effect on MLR. Furthermore, the use of CsA and rD-mPGPtide together for prevention of GVHD nearly doubled the median survival time of the mice compared to either agent alone. In addition, the combination therapy reduced the requirement for habitual administration of CsA. Therefore, the use of a CD4-CDR3 peptide can complement and potentiate the immunosuppressive effects of CsA in the prevention of GVHD following allogeneic BMT.

Isolation of tyrosinase-specific CD8+ and CD4+ T cell clones from the peripheral blood of melanoma patients following in vitro stimulation with recombinant vaccinia virus

The identification of Ags expressed by tumor cells and recognized by autologous T cells has led to the prospect of treating cancer by adoptive transfer of tumor-reactive T cells selected for Ag specificity. Tyrosinase is an Ag expressed by normal melanocytes as well as melanoma cells for which responses by autologous T cells have been detected. To evaluate the frequency with which tyrosinase-specific T cells can be isolated from melanoma patients for potential use in therapy, a recombinant vaccinia virus expressing tyrosinase was constructed for infection of autologous APCs that could be used to stimulate T cells reactive with this protein. Eight patients were studied, with peripheral blood serving as the source of both responder T cells and autologous APCs. Tyrosinase-specific CD8+ CTL clones were isolated from five of the eight patients with melanoma. The tyrosinase-specific CTL generated in this manner recognized autologous tumor cells as well as targets expressing the recombinant virus vector. CTL clones from three of the individuals were restricted to HLA-A28, -B8, and -B60, which have not previously been identified as alleles that can present immunogenic tyrosinase peptides. Tyrosinase-specific CD4+ T cell clones were isolated from six of the eight patients by stimulation with autologous APCs infected with recombinant vaccinia virus, and all these CD4+ clones were capable of recognizing autologous tumor cells. These studies demonstrate a high prevalence of CD4+ and CD8+ tyrosinase-specific responses in peripheral blood and support the feasibility of using peripheral blood to generate T cells for tumor therapy without the requirement for isolating T cells that have infiltrated tumor sites.

Isolation of tyrosinase-specific CD8+ and CD4+ T cell clones from the peripheral blood of melanoma patients following in vitro stimulation with recombinant vaccinia virus

The identification of Ags expressed by tumor cells and recognized by autologous T cells has led to the prospect of treating cancer by adoptive transfer of tumor-reactive T cells selected for Ag specificity. Tyrosinase is an Ag expressed by normal melanocytes as well as melanoma cells for which responses by autologous T cells have been detected. To evaluate the frequency with which tyrosinase-specific T cells can be isolated from melanoma patients for potential use in therapy, a recombinant vaccinia virus expressing tyrosinase was constructed for infection of autologous APCs that could be used to stimulate T cells reactive with this protein. Eight patients were studied, with peripheral blood serving as the source of both responder T cells and autologous APCs. Tyrosinase-specific CD8+ CTL clones were isolated from five of the eight patients with melanoma. The tyrosinase-specific CTL generated in this manner recognized autologous tumor cells as well as targets expressing the recombinant virus vector. CTL clones from three of the individuals were restricted to HLA-A28, -B8, and -B60, which have not previously been identified as alleles that can present immunogenic tyrosinase peptides. Tyrosinase-specific CD4+ T cell clones were isolated from six of the eight patients by stimulation with autologous APCs infected with recombinant vaccinia virus, and all these CD4+ clones were capable of recognizing autologous tumor cells. These studies demonstrate a high prevalence of CD4+ and CD8+ tyrosinase-specific responses in peripheral blood and support the feasibility of using peripheral blood to generate T cells for tumor therapy without the requirement for isolating T cells that have infiltrated tumor sites.

Cytomegalovirus selectively blocks antigen processing and presentation of its immediate-early gene product

Recognition of virus-infected cells by CD8+ cytotoxic T lymphocytes requires that the viral proteins be processed into peptides, the derived peptides transported into the endoplasmic reticulum and inserted into the binding groove of a major histocompatibility complex class I molecule, and the antigenic complex exported to the cell surface. However, viral pathogens can disrupt this process and interfere with immune recognition. These mechanisms may be vital to large viruses such as human cytomegalovirus (CMV), which causes persistent infection despite producing over 200 potentially antigenic proteins during the sequential immediate-early, early and late phases of viral gene expression. Products of CMV early-phase gene expression can globally block class I presentation and prevent recognition of infected cells by cytotoxic T lymphocytes, but an essential viral transcription factor, the 72K principal immediate-early protein, is abundantly expressed before this blockade. However, only a few host CD8+ cytotoxic T lymphocytes specific for immediate-early protein are present in seropositive individuals, and these lyse CMV-infected cells poorly. Here we demonstrate selective abrogation of immediate-early peptide presentation by a CMV matrix protein with associated kinase activity and suggest that modification of a viral protein can result in limiting access to the processing machinery and evasion of cytotoxic-T-cell recognition.

Human immunodeficiency virus grown in CD4-expressing cells is associated with CD4

Using a CD4-capture immunoassay for gp120, several strains of human immunodeficiency virus type 1 (HIV-1) grown in CD4-expressing T lymphoblastoid cells were found to contain little CD4-reactive gp120 (0.3-1.0 ng/ml) relative to virus titre (10(3.2)-10(5.0) TCID50/ml) and p24 antigen (80-1000 ng/ml). The measured CD4-reactive gp120 concentrations of HIV-1 suspensions grown in CD4-negative human neuroblastoma cells were 100- to 10,000-fold greater than those of HIV-1 grown in CD4-positive lymphoblastoid cells, even though both virus suspensions contained abundant viral gp120 as shown by immunoblot assay. It was postulated that CD4 derived from host cells might be associated with virions, concealing the binding domains of gp120. CD4 association with HIV-1 virions grown in CD4-positive cells was demonstrated directly by immunoblot assay of sucrose gradient-purified virus suspensions and by specific co-sedimentation of 125I-labelled OKT4 with virions propagated in CD4-expressing cells. CD4 coating of primary HIV-1 isolates grown in peripheral blood mononuclear cells was also observed. The biological significance of CD4 coating of HIV particles remains to be determined.

T-cell mediated rejection of gene-modified HIV-specific cytotoxic T lymphocytes in HIV-infected patients

The introduction and expression of genes in somatic cells is an innovative therapy for correcting genetic deficiency diseases and augmenting immune function. A potential obstacle to gene therapy is the elimination of such gene-modified cells by an immune response to novel protein products of the introduced genes. We are conducting an immunotherapy trial in which individuals seropositive for human immunodeficiency virus (HIV) receive CD8+ HIV-specific cytotoxic T cells modified by retroviral transduction to express a gene permitting positive and negative selection. However, five of six subjects developed cytotoxic T-lymphocyte responses specific for the novel protein and eliminated the transduced cytotoxic T cells. The rejection of genetically modified cells by these immunocompromised hosts suggests that strategies to render gene-modified cells less susceptible to host immune surveillance will be required for successful gene therapy of immunocompetent hosts.

A systematic approach to health surveillance in the workplace

This paper reviews the range of health surveillance activities which can be utilized in the workplace by occupational health professionals for assessing fitness for work and contributing to the prevention of occupational illness and promotion of good health. The systematic approach described categorizes health surveillance procedures into occupational or non-occupational, risk-based or unfocused, and as primary, secondary or tertiary preventive measures. All categories of health surveillance are currently being practised to some extent, but the type of surveillance may not match the needs of the workplace in some situation. In order to aid health professionals in deciding which procedures should be implemented, recommendations based on an assessment of health risks are made. The key proposal is to establish a minimum level of periodic health surveillance for all workers based on a targeted lifestyle health risk assessment and a structured health questionnaire. Additional procedures can then be added sequentially as appropriate to manage any health risks in the workplace. The role of the unfocused periodic general medical examination is discussed in the context of the systematic approach and allows occupational professionals to critically appraise its usefulness.

Reconstitution of cellular immunity against cytomegalovirus in recipients of allogeneic bone marrow by transfer of T-cell clones from the donor

BACKGROUND

Cytomegalovirus (CMV) disease in immunocompromised patients correlates with a deficiency of CD8+ cytotoxic T lymphocytes specific for CMV. We evaluated the safety and immunologic effects of immunotherapy with clones of these lymphocytes in recipients of allogeneic bone marrow transplants.

METHODS

Clones of CD8+ cytotoxic T cells specific for CMV proteins were isolated from the blood of bone marrow donors. Fourteen patients each received four intravenous infusions of these clones from their donors beginning 30 to 40 days after marrow transplantation. The reconstitution of cellular immunity against CMV was monitored before and during the period of infusions and for up to 12 weeks after the final infusion. The rearranged genes encoding the T-cell receptor served as markers in evaluating the persistence of the transferred T cells.

RESULTS

No toxic effects related to the infusions were observed. Cytotoxic T cells specific for CMV were reconstituted in all patients. In vitro measurements showed that cytotoxic activity against CMV was significantly increased (P < 0.001) after the infusions in 11 patients who were deficient in such activity before therapy. The level of activity achieved after the infusions was similar to that measured in the donors. Analysis of rearranged T-cell-receptor genes in T cells obtained from two recipients indicated that the transferred clones persisted for at least 12 weeks. Cytotoxic-T-cell activity declined in patients deficient in CD4+ T-helper cells specific for CMV, suggesting that helper-T-cell function is needed for the persistence of transferred CD8+ T cells. Neither CMV viremia nor CMV disease developed in any of the 14 patients.

CONCLUSIONS

The transfer of CMV-specific clones of CD8+ T cells derived from the bone marrow donor is a safe and effective way to reconstitute cellular immunity against CMV after allogeneic marrow transplantation.

Evidence that the 5-HT3 receptors of the rat, mouse and guinea-pig superior cervical ganglion may be different

1. Using grease-gap recordings from the isolated superior cervical ganglion of mouse, rat and guinea-pig, we have compared the depolarization evoked by 5-hydroxytryptamine (5-HT) with that evoked by the selective 5-HT3 receptor agonist 2-methyl-5-HT (2-Me-5-HT). 2. The maximum depolarization induced by 2-Me-5-HT was smaller than that induced by 5-HT in all three species, and particularly in the guinea-pig. 3. The 5-HT2 receptor antagonist ketanserin (1 microM) caused a clear rightward shift of the dose-response curve to 5-HT on the guinea-pig ganglion, but not on the mouse or rat ganglion. Spiperone (0.03 microM) had a quantitatively similar action to ketanserin (0.1 microM) on the 5-HT dose-response curve of the guinea-pig ganglion. Ketanserin had no significant effect on the dose-response curve to 2-Me-5-HT on any of these ganglia. 4. Using 2-Me-5-HT as the agonist, we determined the pA2 values for two 5-HT3 receptor antagonists. The potency of ICS 205-930 varied by approximately 100 fold between the species and that of (+)-tubocurarine varied by over 1000 fold. The differences in the pA2 values of these compounds varied independently among the species. 5. We conclude that 5-HT3 receptors are present on the superior cervical ganglion from the rat, mouse and guinea-pig, but these receptors may be pharmacologically distinct from each other. In addition, the depolarization of the guinea-pig superior cervical ganglion by low concentrations of 5-HT is largely mediated by ketanserin-sensitive receptors.

Alcohol-related expectations among Mexican-American women

The article explores alcohol expectations among Mexican-American women utilizing the Alcohol Expectancy Questionnaire and a series of quantity/frequency alcohol use measures. The results indicate that Mexican-American women generally have similar expectations about the benefits of alcohol use as women in the larger population. Within the sample of Mexican-American women however, there were differences in alcohol expectations based on occupational status and acculturation level: those Mexican-American women who are more acculturated and hold higher professional status occupations have higher expectations of the benefits of alcohol use than less acculturated Mexican-American women in blue-collar or service occupations.

Recovery of HLA-restricted cytomegalovirus (CMV)-specific T-cell responses after allogeneic bone marrow transplant: correlation with CMV disease and effect of ganciclovir prophylaxis

Protection from cytomegalovirus (CMV) disease in immunocompromised hosts has been shown to correlate with recovery of the host virus-specific CD8+ T-cell response. The administration of ganciclovir to immunosuppressed transplant recipients as antiviral prophylaxis has reduced the early risk of CMV disease, but late disease is observed with increased frequency, suggesting that recovery of the CMV-specific T-cell responses necessary for protective immunity may be delayed in these patients. Therefore, we evaluated reconstitution of CMV-specific T-cell responses in 47 bone marrow transplant (BMT) recipients entered on a randomized placebo-controlled study of ganciclovir. The study drug was initiated at a mean of 24 days after BMT. At day 30 to 40, a minority of patients had recovery of T-cell immunity to CMV and the frequency of reconstitution was equivalent in patients randomized to ganciclovir or placebo. The failure of ganciclovir to effect early reconstitution may reflect the short duration of treatment. Early recovery was associated with the infusion of BM from a CMV seropositive donor (P = .07 for CD8+ cytotoxic T cell (CTL), P = .04 for CD4+ Th). Between day 40 and day 90, recovery of deficient CD8+ and CD4+ CMV-specific T-cell responses occurred in the majority of individuals that received placebo, but in a minority of ganciclovir recipients. Two cases of late-onset CMV disease occurred in ganciclovir recipients. In all patients, the presence of a CTL response to CMV conferred protection from subsequent CMV disease (P = .005), and these protective CTL responses are shown to be specific for structural virion proteins similar to the responses in immunocompetent CMV seropositive individuals. These data confirm the importance of CMV-specific T-cell responses and suggest that a delay in recovery of these responses as a result of ganciclovir prophylaxis may contribute to the occurrence of late CMV disease.

Alkali hydrolysis of recombinant proteins allows for the rapid identification of class I MHC-restricted CTL epitopes

The characterization of the epitopes recognized by CTL provides insights into the nature of protective immune responses and facilitates the development of methods to enhance immunity to human pathogens. However, no easily applicable approach for CTL epitope identification has been developed. We present a rapid and efficient method for locating CTL epitopes within a protein. The gene encoding the protein of interest is inserted into an inducible prokaryotic expression vector. Random peptides are then generated by alkali digestion of intact or lysed Escherichia coli expressing the protein and assayed for the presence of the epitope by coating target cells for a standard CTL targeting assay. A large panel of clones containing serial 3'-deletions of the gene is then generated by exonuclease III digestion, and the expressed truncated proteins are similarly analyzed for the presence of the antigenic peptide. The epitope is located by determining the deletion points of clones expressing sequential truncations and differing in Ag expression. This technique was used to identify the H-2Ld-restricted nonamer in E. coli beta-galactosidase, with residues 876-884 representing the naturally processed epitope. To test the applicability of this method to other proteins, two genes from human CMV, an often fatal pathogen in immunocompromised individuals, were screened for HLA class I-restricted epitopes. An HLA-B18-restricted epitope from the CMV major immediate-early protein was found to lie between residues 378 and 389, and an HLA-B35-restricted epitope from the CMV pp65 matrix protein was characterized as residues 123 to 131. The results demonstrate that this technique can be used to rapidly identify CTL epitopes within a chosen protein and should be useful for assaying viral isolates or neoplasms for loss of epitopes after mutation and selection by host immune responses.

Alkali hydrolysis of recombinant proteins allows for the rapid identification of class I MHC-restricted CTL epitopes

The characterization of the epitopes recognized by CTL provides insights into the nature of protective immune responses and facilitates the development of methods to enhance immunity to human pathogens. However, no easily applicable approach for CTL epitope identification has been developed. We present a rapid and efficient method for locating CTL epitopes within a protein. The gene encoding the protein of interest is inserted into an inducible prokaryotic expression vector. Random peptides are then generated by alkali digestion of intact or lysed Escherichia coli expressing the protein and assayed for the presence of the epitope by coating target cells for a standard CTL targeting assay. A large panel of clones containing serial 3'-deletions of the gene is then generated by exonuclease III digestion, and the expressed truncated proteins are similarly analyzed for the presence of the antigenic peptide. The epitope is located by determining the deletion points of clones expressing sequential truncations and differing in Ag expression. This technique was used to identify the H-2Ld-restricted nonamer in E. coli beta-galactosidase, with residues 876-884 representing the naturally processed epitope. To test the applicability of this method to other proteins, two genes from human CMV, an often fatal pathogen in immunocompromised individuals, were screened for HLA class I-restricted epitopes. An HLA-B18-restricted epitope from the CMV major immediate-early protein was found to lie between residues 378 and 389, and an HLA-B35-restricted epitope from the CMV pp65 matrix protein was characterized as residues 123 to 131. The results demonstrate that this technique can be used to rapidly identify CTL epitopes within a chosen protein and should be useful for assaying viral isolates or neoplasms for loss of epitopes after mutation and selection by host immune responses.

CD8+ cytotoxic T cell therapy of cytomegalovirus and HIV infection

The development of CD8+ cytotoxic T cell responses to viral pathogens is crucial for the prompt resolution of acute infections and for the control of viruses which persist in the host. Thus, cytomegalovirus often causes life threatening disease in immunosuppressed humans who fail to develop or maintain CD8+ cytotoxic T cells. Similarly, the loss of CD8+ cytotoxic T cell responses to HIV correlates with the development of AIDS. Recent investigations in the immunobiology of cytomegalovirus and HIV have resulted in the application of immunotherapeutic strategies designed to reconstitute or augment deficient CD8+ cytotoxic T cell responses to these human pathogens.

Selective interference with class I major histocompatibility complex presentation of the major immediate-early protein following infection with human cytomegalovirus

Responses of cytotoxic T-cells (Tc) to human cytomegalovirus (CMV) represent the predominant mechanism by which hosts resist CMV infection. The CMV major immediate-early protein (IE) is present throughout the virus replicative cycle. Studies were performed to determine whether Tc specific for IE effectively lyse CMV-infected targets and are thus capable of providing protective immunity against infection. After in vitro stimulation of peripheral blood mononuclear cells with CMV-infected autologous fibroblasts, Tc specific for IE were not readily detectable in CMV-reactive polyclonal Tc lines. However, after stimulation of peripheral blood mononuclear cells with cells selectively expressing IE, weak but detectable IE-specific Tc responses were observed. The frequency of IE-specific Tc clones derived from cultures stimulated with IE-expressing cells was 50 to 100 times lower than the frequency of Tc clones specific for other CMV proteins isolated from cultures stimulated with CMV-infected cells. All of the IE-specific Tc clones, which efficiently lysed targets selectively expressing IE, demonstrated minimal lysis of CMV-infected fibroblasts, despite abundant IE expression in these target cells. In contrast to these results with IE, other viral proteins were efficiently presented during all phases of CMV infection. These data suggest that CMV has evolved a unique mechanism for selectively limiting the presentation of the potentially immunogenic IE protein, which may preclude IE-specific Tc from providing protective immunity to CMV infection.

Psychosocial and cognitive correlates of alcohol use in younger adult immigrant and U.S.-born Hispanics

Hispanic groups, taken together, constitute nearly 9% of the U.S. population. Research undertaken in the last decade has demonstrated that segments of the Hispanic male population are particularly heavy drinkers and are at high risk for alcohol-related problems. This article reviews several of the most important studies of alcohol use and its consequences among Hispanics, and reports new data from a study of alcohol use and its correlates among 452 young adult men and women in Los Angeles. The findings show important differences between immigrants and U.S.-born Hispanics as well as clear gender differences in terms of alcohol use patterns, expectations about the benefits of alcohol consumption, and depressive symptomatology associated with the use of alcohol. These differences have implications for the design of prevention and treatment services for Hispanics and these are discussed.

A novel series of non-quaternary oxadiazoles acting as full agonists at muscarinic receptors

1 A novel series of non-quaternary oxadiazole-based muscarinic agonists demonstrated high affinity for muscarinic receptors. 2. These agonists possessed high efficacy in the nanomolar range at muscarinic receptors in the superior cervical ganglion, atrium and ileum but did not show selectivity across the tissue preparations. 3. Two amino oxadiazoles, one from a quinuclidine series (L-660,863) and one from a 1-azanorbornane series (L-670,207) possessed a high ratio of potency for displacing the binding of [3H]-N-methyl-scopolamine ([3H]-NMS) to potency for displacing the agonist [3H]-oxotremorine-M cortex. 4. The two azanorbornane derivatives L-670,548 and L-670,207 stimulated the turnover of phosphatidylinositol in the cortex with a potency higher than that obtained with any other known muscarinic agonist (ED50 0.26 and 0.18 microM respectively). 5. The maximum response obtained with L-670,207 was greater than that observed for carbachol but was comparable to that of the natural ligand acetylcholine. 6. These oxadiazole muscarinic agonists are among the most potent and efficacious non-quaternary muscarinic agonists ever described.

The anthropologist as alcohologist: qualitative perspectives and methods in alcohol research

As research disciplines differ from each other in terms of their epistemological and theoretical assumptions, they differ in the kinds of data they produce. This paper discusses the particular perspectives and methods that anthropologically produced data contribute to a biopsychosocial paradigm of alcohol use/pathology. Strategic uses of qualitative research approaches are suggested, and situations in which qualitatively produced data would be especially useful in the design and delivery of alcohol-related services are identified.

Hexahydrodifenidol does not distinguish among M1 receptors in rat cerebral cortex, hippocampus and superior cervical ganglion

We have determined the antagonist affinity of hexahydrodifenidol in a range of receptor assays in the rat:-radioreceptor binding and phosphatidyl-inositol turnover assays in cerebral cortex and hippocampus, and electrophysiological experiments on the superior cervical ganglion and hippocampus. We failed to detect any appreciable differences in the affinity of hexahydrodifenidol among any of these assays.

Biphasic dose-response curve to muscarine on the rat superior cervical ganglion

The dose-response curve for the muscarine-induced depolarisation of the rat isolated superior cervical ganglion, studied over the concentration range of 3 nM-1 mM, was biphasic. An apparent maximum was obtained at around 1-3 microM muscarine, but this was only a plateau between the two parts of the curve. Two cardioselective antagonists, gallamine (10 microM) and AF-DX 116 (1 microM) had a complex action on this dose-response curve. The dose-response curve between 0.01 and 0.3 microM was shifted to the right, the responses around 3 microM muscarine were enhanced, but the dose-response curve over 30 microM muscarine was unaffected. The M1-selective antagonist pirenzepine (0.05 microM) depressed all parts of the dose-response curve, but it still appeared biphasic. Pretreatment of the ganglion with pertussis toxin (1 microgram/ml) enhanced the depolarisation to muscarine 0.01-1000 microM and the dose-response curve became less biphasic. Like gallamine and AF-DX 116, pertussis toxin abolished the muscarinic M2-mediated hyperpolarisation of the ganglion recorded in 0.3 microM pirenzepine. It is concluded that the presence of an underlying M2-mediated hyperpolarisation contributes to the biphasic nature of the dose-response curve to muscarine.

Pertussis toxin sensitivity of drug-induced potentials on the rat superior cervical ganglion

We have investigated the action of pertussis toxin on a range of receptor-mediated responses of the rat superior cervical ganglion in vitro. The ganglia were treated with pertussis toxin for 24 h at 37 degrees C using an in vitro method. Appropriate controls were also carried out. Pertussis toxin (1 microgram/ml) reduced ganglionic hyperpolarisations mediated by adenosine, alpha 2, 5-HT1A, M2 and GABAB receptors. The GABAB-mediated hyperpolarisation of this preparation, evoked by baclofen and GABA in a bicuculline-resistant manner, has not previously been reported. Pertussis toxin did not reduce ganglionic depolarisations evoked by potassium chloride and 5-HT3, GABAA and nicotinic receptors. Depolarisations to muscarine and noradrenaline, probably mediated by M1 and beta-receptors, also appeared to be resistant to pertussis toxin. The similar sensitivity of the various ganglionic hyperpolarisations to pertussis toxin indicates that they may all be mediated by similar G-proteins.

5-Hydroxytryptamine evokes three distinct responses on the rat superior cervical ganglion in vitro

In addition to the 5-HT3-mediated fast depolarisation, 5-hydroxytryptamine (5-HT) evoked two additional responses on the rat superior cervical ganglion: a hyperpolarisation and a slow depolarisation. These responses appeared to be direct actions on 5-HT receptors since they were present in a low calcium medium containing tetrodotoxin and were not abolished by a variety of non-serotonin antagonists. The hyperpolarisation was not antagonised by 5-HT3 or 5-HT2 antagonists. The 5-HT1 ligands 5-carboxamidotryptamine (5-CT) and 8-OH-DPAT also evoked a hyperpolarisation. The hyperpolarisation was antagonised by six 5-HT1A antagonists including WB-4101 and spiroxatrine. It was therefore concluded to be mediated by a 5-HT1A receptor. The slow depolarisation was only evoked by 5-HT. The receptor involved in this response, however, could not be determined. We conclude that in addition to 5-HT3 receptors the rat superior cervical ganglion possesses 5-HT1A receptors and another uncharacterised 5-HT receptor.