Structural features associated with multiferroic behavior in the RX3(BO3)4 system

The magnetoelectric effect in the RX₃(BO₃)₄ system (R  =  Ho, Eu, Sm, Nd, Gd; X  =  Fe, Al) varies significantly with the cation R despite very similar structural arrangements. Our structural studies reveal a symmetry reducing tilting of the BO₃ planes and of the FeO₆ polyhedra in the systems exhibiting low magnetic field induced electric polarization. Neutron scattering measurements reveal a lack of magnetic ordering indicating the primary importance of the atomic structure in the multiferroic behavior of this system.

The role for ketogenic diets in epilepsy and status epilepticus in adults

•

Ketogenic diets offer adjunctive therapy for chronic epilepsy and refractory status epilepticus.

•

Studies support feasibility and efficacy of the classic ketogenic diet and its variants in adults.

•

Potential complications and side effects of diet therapy are often preventable and manageable.

•

Strategies are needed to improve diet adherence.

Ketogenic diet (KD) therapies are high fat, low carbohydrate diets designed to mimic a fasting state. Although studies demonstrate KD’s success in reducing seizures stretching back nearly a century, the last 25 years have seen a resurgence in diet therapy for the management of drug-resistant epilepsy in children as well as adults. With ≥50% seizure reduction efficacy rates in adults of 22–55% for the classic KD and 12–67% for the modified Atkins diet, diet therapy may be in many instances comparable to a trial of an additional anti-epileptic medication and potentially with fewer side effects and other health benefits. Moreover, ketogenic diets offer promising new adjunctive strategies for the treatment of acute status epilepticus in the intensive care setting. Here, we review the efficacy and utility of ketogenic diets for the management of chronic epilepsy and refractory status epilepticus in adults and offer practical guidelines for diet implementation and maintenance.

Association of Autoimmune Encephalitis With Combined Immune Checkpoint Inhibitor Treatment for Metastatic Cancer

IMPORTANCE

Paraneoplastic encephalitides usually precede a diagnosis of cancer and are often refractory to immunosuppressive therapy. Conversely, autoimmune encephalitides are reversible conditions that can occur in the presence or absence of cancer.

OBJECTIVE

To report the induction of autoimmune encephalitis in 2 patients after treatment of metastatic cancer with a combination of the immune checkpoint inhibitors nivolumab and ipilimumab.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective case study was conducted of the clinical and management course of 2 patients with progressive, treatment-refractory metastatic cancer who were treated with a single dose each (concomitantly) of the immune checkpoint inhibitors nivolumab, 1 mg/kg, and ipilimumab, 3 mg/kg.

EXPOSURES

Nivolumab and ipilimumab.

MAIN OUTCOMES AND MEASURES

The clinical response to immunosuppressive therapy in suspected autoimmune encephalitis in the setting of immune checkpoint inhibitor use.

RESULTS

Autoantibody testing confirmed identification of anti-N-methyl-D-aspartate receptor antibodies in the cerebrospinal fluid of 1 patient. Withdrawal of immune checkpoint inhibitors and initiation of immunosuppressive therapy, consisting of intravenous methylprednisolone sodium succinate equivalent to 1000 mg of methylprednisolone for 5 days, 0.4 mg/kg/d of intravenous immunoglobulin for 5 days, and 2 doses of rituximab, 1000 mg, in 1 patient and oral prednisone, 60 mg/d, in the other patient, resulted in improved neurologic symptoms.

CONCLUSIONS AND RELEVANCE

Immune checkpoint inhibition may favor the development of immune responses against neuronal antigens, leading to autoimmune encephalitis. Early recognition and treatment of autoimmune encephalitis in patients receiving immune checkpoint blockade therapy will likely be essential for maximizing clinical recovery and minimizing the effect of drug-related toxic effects. The mechanisms by which immune checkpoint inhibition may contribute to autoimmune encephalitis require further study.

Morphological and proteomic analysis of biofilms from the Antarctic archaeon, Halorubrum lacusprofundi

Biofilms enhance rates of gene exchange, access to specific nutrients, and cell survivability. Haloarchaea in Deep Lake, Antarctica, are characterized by high rates of intergenera gene exchange, metabolic specialization that promotes niche adaptation, and are exposed to high levels of UV-irradiation in summer. Halorubrum lacusprofundi from Deep Lake has previously been reported to form biofilms. Here we defined growth conditions that promoted the formation of biofilms and used microscopy and enzymatic digestion of extracellular material to characterize biofilm structures. Extracellular DNA was found to be critical to biofilms, with cell surface proteins and quorum sensing also implicated in biofilm formation. Quantitative proteomics was used to define pathways and cellular processes involved in forming biofilms; these included enhanced purine synthesis and specific cell surface proteins involved in DNA metabolism; post-translational modification of cell surface proteins; specific pathways of carbon metabolism involving acetyl-CoA; and specific responses to oxidative stress. The study provides a new level of understanding about the molecular mechanisms involved in biofilm formation of this important member of the Deep Lake community.

Developing a genetic manipulation system for the Antarctic archaeon, Halorubrum lacusprofundi: investigating acetamidase gene function

No systems have been reported for genetic manipulation of cold-adapted Archaea. Halorubrum lacusprofundi is an important member of Deep Lake, Antarctica (~10% of the population), and is amendable to laboratory cultivation. Here we report the development of a shuttle-vector and targeted gene-knockout system for this species. To investigate the function of acetamidase/formamidase genes, a class of genes not experimentally studied in Archaea, the acetamidase gene, amd3, was disrupted. The wild-type grew on acetamide as a sole source of carbon and nitrogen, but the mutant did not. Acetamidase/formamidase genes were found to form three distinct clades within a broad distribution of Archaea and Bacteria. Genes were present within lineages characterized by aerobic growth in low nutrient environments (e.g. haloarchaea, Starkeya) but absent from lineages containing anaerobes or facultative anaerobes (e.g. methanogens, Epsilonproteobacteria) or parasites of animals and plants (e.g. Chlamydiae). While acetamide is not a well characterized natural substrate, the build-up of plastic pollutants in the environment provides a potential source of introduced acetamide. In view of the extent and pattern of distribution of acetamidase/formamidase sequences within Archaea and Bacteria, we speculate that acetamide from plastics may promote the selection of amd/fmd genes in an increasing number of environmental microorganisms.

Donation After Circulatory Determination of Death Lung Transplantation for Pulmonary Arterial Hypertension: Passing the Toughest Test

Lung transplantation (LTx) is a therapeutic option for severe pulmonary arterial hypertension (PAH) patients failing optimal medical therapy. The use of donation after circulatory determination of death (DCDD) donor lungs for PAH LTx has rarely been reported, primarily reflecting concerns that DCDD lungs represent extended criteria donors, at risk of morbidity and mortality. A retrospective study of all Alfred Hospital DCDD and DNDD (donation after neurologic determination of death) PAH LTx was undertaken. Protocolized fluid/inotrope/ventilator and extracorporeal membrane oxygenation (ECMO) strategies were utilized. Since our first DCDD LTx in 2006, 512 LTx have been performed. Of 31 PAH recipients, 11 received DCDD lungs (11% of DCDD LTx) and 20 received DNDD lungs (5% of DNDD LTx) (p = 0.04). Only one PAH patient died on the LTx waiting list. Peri-LTx ECMO was utilized in 3/11 (27%) DCDD and 6/20 (30%) DNDD PAH LTx (p = 0.68). Primary graft dysfunction, intensive care, and overall stay were the same in both groups. Survival at 1 and 8 years was 100% and 80% for DCDD versus 100% and 70% for DNDD LTx (p = 0.88), respectively. In conclusion, excellent results can be achieved for PAH LTx. DCDD donor lungs are not extended lungs per se having passed the toughest test.

Stress differentially alters mu opioid receptor density and trafficking in parvalbumin-containing interneurons in the female and male rat hippocampus

Stress differentially affects hippocampal-dependent learning relevant to addiction and morphology in male and female rats. Mu opioid receptors (MORs), which are located in parvalbumin (PARV)-containing GABAergic interneurons and are trafficked in response to changes in the hormonal environment, play a critical role in promoting principal cell excitability and long-term potentiation. Here, we compared the effects of acute and chronic immobilization stress (AIS and CIS) on MOR trafficking in PARV-containing neurons in the hilus of the dentate gyrus in female and male rats using dual label immunoelectron microscopy. Following AIS, the density of MOR silver-intensified gold particles (SIGs) in the cytoplasm of PARV-labeled dendrites was significantly reduced in females (estrus stage). Conversely, AIS significantly increased the proportion of cytoplasmic MOR SIGs in PARV-labeled dendrites in male rats. CIS significantly reduced the number of PARV-labeled neurons in the dentate hilus of males but not females. However, MOR/PARV-labeled dendrites and terminals were significantly smaller in CIS females, but not males, compared with controls. Following CIS, the density of cytoplasmic MOR SIGs increased in PARV-labeled dendrites and terminals in females. Moreover, the proportion of near-plasmalemmal MOR SIGs relative to total decreased in large PARV-labeled dendrites in females. After CIS, no changes in the density or trafficking of MOR SIGs were seen in PARV-labeled dendrites or terminals in males. These data show that AIS and CIS differentially affect available MOR pools in PARV-containing interneurons in female and male rats. Furthermore, they suggest that CIS could affect principal cell excitability in a manner that maintains learning processes in females but not males.

The influences of reproductive status and acute stress on the levels of phosphorylated delta opioid receptor immunoreactivity in rat hippocampus

In the hippocampus, ovarian hormones and sex can alter the trafficking of delta opioid receptors (DORs) and the proportion of DORs that colocalize with the stress hormone, corticotropin releasing factor. Here, we assessed the effects of acute immobilization stress (AIS) and sex on the phosphorylation of DORs in the rat hippocampus. We first localized an antibody to phosphorylated DOR (pDOR) at the SER363 carboxy-terminal residue, and demonstrated its response to an opioid agonist. By light microscopy, pDOR-immunoreactivity (ir) was located predominantly in CA2/CA3a pyramidal cell apical dendrites and in interneurons in CA1-3 stratum oriens and the dentate hilus. By electron microscopy, pDOR-ir primarily was located in somata and dendrites, associated with endomembranes, or in dendritic spines. pDOR-ir was less frequently found in mossy fibers terminals. Quantitative light microscopy revealed a significant increase in pDOR-ir in the CA2/CA3a region of male rats 1h following an injection of the opioid agonist morphine (20mg/kg, I.P). To look at the effects of stress on pDOR, we compared pDOR-ir in males and cycling females after AIS. The level of pDOR-ir in stratum radiatum of CA2/CA3a was increased in control estrus (elevated estrogen and progesterone) females compared to proestrus and diestrus females and males. However, immediately following 30min of AIS, no significant differences in pDOR levels were seen across estrous cycle phase or sex. These findings suggest that hippocampal levels of phosphorylated DORs vary with estrous cycle phase and that acute stress may dampen the differential effects of hormones on DOR activation in females.

A technique for sexing mouse embryos by a visual colorimetric assay of the X-linked enzyme, glucose 6-phosphate dehydrogenase

Described is a simple visual, colorimetric assay for the X-linked enzyme, glucose 6-phosphate dehydrogenase (G6PD), in mouse embryos. Included is a demonstration of the effectiveness of the assay in predicting the sex of embryos prior to transfer. Scoring of embryos according to G6PD content resulted in an apparent bimodal distribution with 50% scoring as females, i.e., double dosage of G6PD, and 50% scoring as males, i.e., single dosage of G6PD. Transfer of "sexed" embryos to surrogate mothers resulted in an overall birth rate of 35% (181 516 ) compared to 46% (39 84 ) for controls. Embryos predicted as females resulted in a birth rate of 35% (86 247 ), and 72% (62 86 ) of pups born were female. Embryos predicted as males resulted in a birth rate of 35% (95 269 ), and 57% (54 95 ) of pups born were male. Overall, the accuracy of the assay was 64% (116 181 ) in predicting sex, i.e., about two-thirds of the embryos were correctly sexed prior to transfer.

Measurement of granulocyte pharmacodynamics in whole blood by flow cytometry

During the Phase I/II assessment of new therapies with the potential to suppress eosinophil and neutrophil inflammation, there is a need to assess the peripheral blood pharmacokinetic (PK) and pharmacodynamic (PD) profiles of the drug. This has relevance in respiratory disease since drugs that target eosinophillic inflammation are in development for asthma; whereas neutrophil-directed therapies are being introduced for treatment of chronic obstructive airways disease (COPD). Pharmacokinetic evaluation is required to determine the concentration of drug substance (and possibly metabolites) in peripheral blood at intervals following single or repeated dosing. Pharmacodynamic assessment is also required since many drug substances have a duration of action which is prolonged beyond the time when drug substance is detectable in the blood (see Fig. 1). Fig. 1. Whole blood pharmacodynamics. In preclinical studies, animal or human blood is treated with test agents. In clinical studies, human subjects are treated with drug and blood removed for analysis. GAFS, gated autofluorescence forward scatter; PK, pharmacokinetics; PD, pharmacoldynamics.

New magnetic phase diagram of (Sr,Ca)2RuO4

High-T(c) cuprates, iron pnictides, organic BEDT and TMTSF, alkali-doped C(60), and heavy-fermion systems have superconducting states adjacent to competing states exhibiting static antiferromagnetic or spin density wave order. This feature has promoted pictures for their superconducting pairing mediated by spin fluctuations. Sr(2)RuO(4) is another unconventional superconductor which almost certainly has a p-wave pairing. The absence of known signatures of static magnetism in the Sr-rich side of the (Ca, Sr) substitution space, however, has led to a prevailing view that the superconducting state in Sr(2)RuO(4) emerges from a surrounding Fermi-liquid metallic state. Using muon spin relaxation and magnetic susceptibility measurements, we demonstrate here that (Sr,Ca)(2)RuO(4) has a ground state with static magnetic order over nearly the entire range of (Ca, Sr) substitution, with spin-glass behaviour in Sr(1.5)Ca(0.5)RuO(4) and Ca(1.5)Sr(0.5)RuO(4). The resulting new magnetic phase diagram establishes the proximity of superconductivity in Sr(2)RuO(4) to competing static magnetic order.

Spin ice: magnetic excitations without monopole signatures using muon spin rotation

Theory predicts the low temperature magnetic excitations in spin ices consist of deconfined magnetic charges, or monopoles. A recent transverse-field (TF) muon spin rotation (μSR) experiment [S. T. Bramwell et al., Nature (London) 461, 956 (2009)] reports results claiming to be consistent with the temperature and magnetic field dependence anticipated for monopole nucleation-the so-called second Wien effect. We demonstrate via a new series of μSR experiments in Dy(2)Ti(2)O(7) that such an effect is not observable in a TF μSR experiment. Rather, as found in many highly frustrated magnetic materials, we observe spin fluctuations which become temperature independent at low temperatures, behavior which dominates over any possible signature of thermally nucleated monopole excitations.

The influences of reproductive status and acute stress on the levels of phosphorylated mu opioid receptor immunoreactivity in rat hippocampus

Opioids play a critical role in hippocampally dependent behavior and plasticity. In the hippocampal formation, mu opioid receptors (MOR) are prominent in parvalbumin (PARV) containing interneurons. Previously we found that gonadal hormones modulate the trafficking of MORs in PARV interneurons. Although sex differences in response to stress are well documented, the point at which opioids, sex and stress interact to influence hippocampal function remains elusive. Thus, we used quantitative immunocytochemistry in combination with light and electron microscopy for the phosphorylated MOR at the SER375 carboxy-terminal residue (pMOR) in male and female rats to assess these interactions. In both sexes, pMOR-immunoreactivity (ir) was prominent in axons and terminals and in a few neuronal somata and dendrites, some of which contained PARV in the mossy fiber pathway region of the dentate gyrus (DG) hilus and CA3 stratum lucidum. In unstressed rats, the levels of pMOR-ir in the DG or CA3 were not affected by sex or estrous cycle stage. However, immediately following 30 minutes of acute immobilization stress (AIS), males had higher levels of pMOR-ir whereas females at proestrus and estrus (high estrogen stages) had lower levels of pMOR-ir within the DG. In contrast, the number and types of neuronal profiles with pMOR-ir were not altered by AIS in either males or proestrus females. These data demonstrate that although gonadal steroids do not affect pMOR levels at resting conditions, they are differentially activated both pre- and post-synaptic MORs following stress. These interactions may contribute to the reported sex differences in hippocampally dependent behaviors in stressed animals.

Ovarian hormones influence corticotropin releasing factor receptor colocalization with delta opioid receptors in CA1 pyramidal cell dendrites

Stress interacts with addictive processes to increase drug use, drug seeking, and relapse. The hippocampal formation (HF) is an important site at which stress circuits and endogenous opioid systems intersect and likely plays a critical role in the interaction between stress and drug addiction. Our prior studies demonstrate that the stress-related neuropeptide corticotropin-releasing factor (CRF) and the delta-opioid receptor (DOR) colocalize in interneuron populations in the hilus of the dentate gyrus and stratum oriens of CA1 and CA3. While independent ultrastructural studies of DORs and CRF receptors suggest that each receptor is found in CA1 pyramidal cell dendrites and dendritic spines, whether DORs and CRF receptors colocalize in CA1 neuronal profiles has not been investigated. Here, hippocampal sections of adult male and proestrus female Sprague-Dawley rats were processed for dual label pre-embedding immunoelectron microscopy using well-characterized antisera directed against the DOR for immunoperoxidase and against the CRF receptor for immunogold. DOR-immunoreactivity (-ir) was found presynaptically in axons and axon terminals as well as postsynaptically in somata, dendrites and dendritic spines in stratum radiatum of CA1. In contrast, CRF receptor-ir was predominantly found postsynaptically in CA1 somata, dendrites, and dendritic spines. CRF receptor-ir frequently was observed in DOR-labeled dendritic profiles and primarily was found in the cytoplasm rather than at or near the plasma membrane. Quantitative analysis of CRF receptor-ir colocalization with DOR-ir in pyramidal cell dendrites revealed that proestrus females and males show comparable levels of CRF receptor-ir per dendrite and similar cytoplasmic density of CRF receptor-ir. In contrast, proestrus females display an increased number of dual-labeled dendritic profiles and an increased membrane density of CRF receptor-ir in comparison to males. We further examined the functional consequences of CRF receptor-ir colocalization with DOR-ir in the same neuron using the hormone responsive neuronal cell line NG108-15, which endogenously expresses DORs, and assayed intracellular cAMP production in response to CRF receptor and DOR agonists. Results demonstrated that short-term application of DOR agonist SNC80 inhibited CRF-induced cAMP accumulation in NG108-15 cells transfected with the CRF receptor. These studies provide new insights on opioid-stress system interaction in the hippocampus of both males and females and establish potential mechanisms through which DOR activation may influence CRF receptor activity.

Delta opioid receptors colocalize with corticotropin releasing factor in hippocampal interneurons

The hippocampal formation (HF) is an important site at which stress circuits and endogenous opioid systems intersect, likely playing a critical role in the interaction between stress and drug addiction. Prior study findings suggest that the stress-related neuropeptide corticotropin releasing factor (CRF) and the delta opioid receptor (DOR) may localize to similar neuronal populations within HF lamina. Here, hippocampal sections of male and cycling female adult Sprague-Dawley rats were processed for immunolabeling using antisera directed against the DOR and CRF peptide, as well as interneuron subtype markers somatostatin or parvalbumin, and analyzed by fluorescence and electron microscopy. Both DOR- and CRF-labeling was observed in interneurons in the CA1, CA3, and dentate hilus. Males and normal cycling females displayed a similar number of CRF immunoreactive neurons co-labeled with DOR and a similar average number of CRF-labeled neurons in the dentate hilus and stratum oriens of CA1 and CA3. In addition, 70% of DOR/CRF dual-labeled neurons in the hilar region co-labeled with somatostatin, suggesting a role for these interneurons in regulating perforant path input to dentate granule cells. Ultrastructural analysis of CRF-labeled axon terminals within the hilar region revealed that proestrus females have a similar number of CRF-labeled axon terminals that contain DORs compared to males but an increased number of CRF-labeled axon terminals without DORs. Taken together, these findings suggest that while DORs are anatomically positioned to modulate CRF immunoreactive interneuron activity and CRF peptide release, their ability to exert such regulatory activity may be compromised in females when estrogen levels are high.

Biotechnological uses of enzymes from psychrophiles

The bulk of the Earth's biosphere is cold (e.g. 90% of the ocean's waters are ≤ 5°C), sustaining a broad diversity of microbial life. The permanently cold environments vary from the deep ocean to alpine reaches and to polar regions. Commensurate with the extent and diversity of the ecosystems that harbour psychrophilic life, the functional capacity of the microorganisms that inhabitat the cold biosphere are equally diverse. As a result, indigenous psychrophilic microorganisms provide an enormous natural resource of enzymes that function effectively in the cold, and these cold‐adapted enzymes have been targeted for their biotechnological potential. In this review we describe the main properties of enzymes from psychrophiles and describe some of their known biotechnological applications and ways to potentially improve their value for biotechnology. The review also covers the use of metagenomics for enzyme screening, the development of psychrophilic gene expression systems and the use of enzymes for cleaning.

Hormonal regulation of delta opioid receptor immunoreactivity in interneurons and pyramidal cells in the rat hippocampus

Clinical and preclinical studies indicate that women and men differ in relapse vulnerability to drug-seeking behavior during abstinence periods. As relapse is frequently triggered by exposure of the recovered addict to objects previously associated with drug use and the formation of these associations requires memory systems engaged by the hippocampal formation (HF), studies exploring ovarian hormone modulation of hippocampal function are warranted. Previous studies revealed that ovarian steroids alter endogenous opioid peptide levels and trafficking of mu opioid receptors in the HF, suggesting cooperative interaction between opioids and estrogens in modulating hippocampal excitability. However, whether ovarian steroids affect the levels or trafficking of delta opioid receptors (DORs) in the HF is unknown. Here, hippocampal sections of adult male and normal cycling female Sprague-Dawley rats were processed for quantitative immunoperoxidase light microscopy and dual label fluorescence or immunoelectron microscopy using antisera directed against the DOR and neuropeptide Y (NPY). Consistent with previous studies in males, DOR-immunoreactivity (-ir) localized to select interneurons and principal cells in the female HF. In comparison to males, females, regardless of estrous cycle phase, show reduced DOR-ir in the granule cell layer of the dentate gyrus and proestrus (high estrogen) females, in particular, display reduced DOR-ir in the CA1 pyramidal cell layer. Ultrastructural analysis of DOR-labeled profiles in CA1 revealed that while females generally show fewer DORs in the distal apical dendrites of pyramidal cells, proestrus females, in particular, exhibit DOR internalization and trafficking towards the soma. Dual label studies revealed that DORs are found in NPY-labeled interneurons in the hilus, CA3, and CA1. While DOR colocalization frequency in NPY-labeled neuron somata was similar between animals in the hilus, proestrus females had fewer NPY-labeled neurons that co-labeled with DOR in stratum oriens of CA1 and CA3 when compared to males. Ultrastructural analysis of NPY-labeled axon terminals within stratum radiatum of CA1 revealed that NPY-labeled axon terminals contain DORs that are frequently found at or near the plasma membrane. As no differences were noted by sex or estrous cycle phase, DOR activation on NPY-labeled axon terminals would inhibit GABA release probability equally in males and females. Taken together, these findings suggest that ovarian steroids can impact hippocampal function through direct effects on DOR levels and trafficking in principal cells and broad indirect effects through reductions in DOR-ir in NPY-labeled interneurons, particularly in CA1.

A comparison of the structure of solute clusters formed during thermal ageing and irradiation

Nanometre scale clusters form in Cu-containing reactor pressure vessel (RPV) steels during neutron irradiation. These clusters have a deleterious effect on mechanical properties, which can result in embrittlement and limit the reactor operating life. Thermal ageing of RPV steels can also induce the formation of solute clusters but it is not clear how similar these are to those formed during irradiation. In this work atom probe tomography, combined with detailed structural assessments of the structure of solute clusters, is used to address this issue. A series of thermal ageing heat treatments has been performed on several high- and low-Ni RPV welds to produce 1-4 nm diameter solute clusters. The same materials have also been neutron irradiated. The results show that CuMnNiSi enriched clusters formed during thermal ageing have, on average, higher Cu contents and lower Mn, Ni and Si contents than those found in irradiation-induced clusters. The effect of increasing bulk Ni is to encourage the formation of clusters with significantly higher Ni content, slightly higher Mn and Si contents and significantly lower Cu contents. At very high doses and dose rates MnNiSi enriched clusters can form even in high-Cu welds. Despite differences in the compositions of individual clusters formed during irradiation and during thermal ageing, clusters in both exhibit similar structure. In particular, well developed clusters in both materials have Cu-enriched cores whose peripheries are enriched in Ni, Mn and, in most cases, Si.

Temperature-dependent global gene expression in the Antarctic archaeon Methanococcoides burtonii

Methanococcoides burtonii is a member of the Archaea that was isolated from Ace Lake in Antarctica and is a valuable model for studying cold adaptation. Low temperature transcriptional regulation of global gene expression, and the arrangement of transcriptional units in cold-adapted archaea has not been studied. We developed a microarray for determining which genes are expressed in operons, and which are differentially expressed at low (4°C) or high (23°C) temperature. Approximately 55% of genes were found to be arranged in operons that range in length from 2 to 23 genes, and mRNA abundance tended to increase with operon length. Analysing microarray data previously obtained by others for Halobacterium salinarum revealed a similar correlation between operon length and mRNA abundance, suggesting that operons may play a similar role more broadly in the Archaea. More than 500 genes were differentially expressed at levels up to ≈ 24-fold. A notable feature was the upregulation of genes involved in maintaining RNA in a state suitable for translation in the cold. Comparison between microarray experiments and results previously obtained using proteomics indicates that transcriptional regulation (rather than translation) is primarily responsible for controlling gene expression in M. burtonii. In addition, certain genes (e.g. involved in ribosome structure and methanogenesis) appear to be regulated post-transcriptionally. This is one of few experimental studies describing the genome-wide distribution and regulation of operons in archaea.

Age- and hormone-regulation of opioid peptides and synaptic proteins in the rat dorsal hippocampal formation

Circulating estrogen levels and hippocampal-dependent cognitive functions decline with aging. Moreover, the responses of hippocampal synaptic structure to estrogens differ between aged and young rats. We recently reported that estrogens increase levels of post-synaptic proteins, including PSD-95, and opioid peptides leu-enkephalin and dynorphin in the hippocampus of young animals. However, the influence of ovarian hormones on synaptic protein and opioid peptide levels in the aging hippocampus is understudied. Here, young (3- to 5-month-old), middle-aged (9- to 12-month-old), and aged (about 22-month-old) female rats were ovariectomized and then, 4 weeks later, subcutaneously implanted with a silastic capsule containing vehicle or 17β-estradiol. After 48 h, rats were subcutaneously injected with progesterone or vehicle and sacrificed 1 day later. Coronal sections through the dorsal hippocampus were processed for quantitative peroxidase immunohistochemistry of leu-enkephalin, dynorphin, synaptophysin, and PSD-95. With age, females showed opposing changes in leu-enkephalin and dynorphin levels in the mossy fiber pathway, particularly within the hilus, and regionally specific changes in synaptic protein levels. 17β-estradiol, with or without progesterone, altered leu-enkephalin levels in the dentate gyrus and synaptophysin levels in the CA1 of young but not middle-aged or aged females. Additionally, 17β-estradiol decreased synaptophysin levels in the CA3 of middle-aged females. Our results support and extend previous findings indicating 17β-estradiol modulation of hippocampal opioid peptides and synaptic proteins while demonstrating regional and age-specific effects. Moreover, they lend credence to the "window of opportunity" hypothesis during which hormone replacement can modulate hippocampal structure and circuitry to improve cognitive outcomes.

The six-minute walk test: a useful metric for the cardiopulmonary patient

Measurement of exercise capacity is an integral element in assessment of patients with cardiopulmonary disease. The 6-min walk test (6MWT) provides information regarding functional capacity, response to therapy and prognosis across a range of chronic cardiopulmonary conditions. A distance less than 350 m is associated with increased mortality in chronic obstructive pulmonary disease, chronic heart failure and pulmonary arterial hypertension. Desaturation during a 6MWT is an important prognostic indicator for patients with interstitial lung disease. The 6MWT is sensitive to commonly used therapies in chronic obstructive pulmonary disease such as pulmonary rehabilitation, oxygen, long-term use of inhaled corticosteroids and lung volume reduction surgery. However, it appears less reliable to detect changes in clinical status associated with medical therapies for heart failure. A change in walking distance of more than 50 m is clinically significant in most disease states. When interpreting the results of a 6MWT, consideration should be given to choice of predictive values and the methods by which the test was carried out.

Ovarian steroids alter mu opioid receptor trafficking in hippocampal parvalbumin GABAergic interneurons

The endogenous hippocampal opioid systems are implicated in learning associated with drug use. Recently, we showed that ovarian hormones regulate enkephalin levels in the mossy fiber pathway. This pathway overlaps with parvalbumin (PARV)-basket interneurons that contain the enkephalin-activated mu opioid receptors (MORs) and are important for controlling the "temporal timing" of granule cells. Here, we evaluated the influence of ovarian steroids on the trafficking of MORs in PARV interneurons. Two groups of female rats were analyzed: cycling rats in proestrus (relatively high estrogens) or diestrus; and ovariectomized rats euthanized 6, 24 or 72 h after estradiol benzoate (10 microg, s.c.) administration. Dorsal hippocampal sections were dually immunolabeled for MOR and PARV and examined by light and electron microscopy. As in males, in females MOR-immunoreactivity (-ir) was in numerous PARV-labeled perikarya, dendrites and terminals in the dentate hilar region. Variation in ovarian steroid levels altered the subcellular distribution of MORs in PARV-labeled dendrites but not terminals. In normal cycling rats, MOR-gold particles on the plasma membrane of small PARV-labeled dendrites (area <1 microm2) had higher density in proestrus rats than in diestrus rats. Likewise, in ovariectomized rats MORs showed higher density on the plasma membrane of small PARV-labeled dendrites 72 h after estradiol exposure. The number of PARV-labeled cells was not affected by estrous cycle phase or estrogen levels. These results demonstrate that estrogen levels positively regulate the availability of MORs on GABAergic interneurons in the dentate gyrus, suggesting cooperative interaction between opioids and estrogens in modulating principal cell excitability.

Hippocampal dynorphin immunoreactivity increases in response to gonadal steroids and is positioned for direct modulation by ovarian steroid receptors

The hippocampal formation (HF) is involved in modulating learning related to drug abuse. While HF-dependent learning is regulated by both endogenous opioids and estrogen, the interaction between these two systems is not well understood. The mossy fiber (MF) pathway formed by dentate gyrus (DG) granule cell axons is involved in some aspects of learning and contains abundant amounts of the endogenous opioid peptide dynorphin (DYN). To examine the influence of ovarian steroids on DYN expression, we used quantitative light microscopic immunocytochemistry to measure DYN levels in normal cycling rats as well as in two established models of hormone-treated ovariectomized (OVX) rats. Rats in estrus had increased levels of DYN-immunoreactivity (ir) in the DG and certain CA3 lamina compared with rats in proestrus or diestrus. OVX rats exposed to estradiol for 24 h showed increased DYN-ir in the DG and CA3, while those with 72 h estradiol exposure showed increases only in the DG. Six hours of estradiol exposure produced no change in DYN-ir. OVX rats chronically implanted with medroxyprogesterone also showed increased DYN-ir in the DG and CA3. Next, dual-labeling electron microscopy (EM) was used to evaluate the subcellular relationships of estrogen receptor (ER) alpha-, ERbeta and progestin receptor (PR) with DYN-labeled MFs. ERbeta-ir was in some DYN-labeled MF terminals and smaller terminals, and had a subcellular association with the plasmalemma and small synaptic vesicles. In contrast, ERalpha-ir was not in DYN-labeled terminals, although some DYN-labeled small terminals synapsed on ERalpha-labeled dendritic spines. PR labeling was mostly in CA3 axons, some of which were continuous with DYN-labeled terminals. These studies indicate that ovarian hormones can modulate DYN in the MF pathway in a time-dependent manner, and suggest that hormonal effects on the DYN-containing MF pathway may be directly mediated by ERbeta and/or PR activation.

Challenges in pulmonary fibrosis: 7--Novel therapies and lung transplantation

The spectrum of diseases collectively known as pulmonary fibrosis does not have reliable therapeutic options. Many treatment protocols have been the subject of clinical trials, resulting in few significant improvements in outcome. Recently, cellular mechanisms have been the focus of investigations in progenitor cell studies, suggesting an immunomodulatory role for mesenchymal stem cells. The possible role of fibrogenic cytokines and the use of antagonist molecules are promising for future therapies. A range of anti-inflammatory treatments, including macrolide antibiotics, may also hold promise. When medical therapy has been unsuccessful in altering the course of the disease, lung transplantation may offer a significant survival advantage. Improvement in pre-transplant assessment and postoperative care, combined with more effective immunosuppressive regimes, has seen survival rates of 40% after 5 years. New options for therapy will lead to improved survival in coming years.

Prodynorphin gene promoter repeat associated with cocaine/alcohol codependence

There is strong evidence for a genetic contribution to individual differences in vulnerability to drug addictions. Studies have shown that the 68-base pair repeat polymorphism in the promoter region of the human prodynorphin gene contains a putative AP-1 binding site, and that three or four repeat copies result in greater transcriptional activation. Here, we report on a separate cohort of 302 subjects ascertained and characterized extensively by Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition and Addiction Severity Index criteria as: (1) a control group of 127 subjects with no history of alcohol or drug abuse or dependence; (3) a case group of 82 with cocaine dependence only; and (3) a case group of 93 with cocaine and alcohol codependence. The promoter region of the prodynorphin gene containing the repeat was amplified from genomic DNA by polymerase chain reaction and analyzed via gel electrophoresis. Statistical tests were performed with data stratified by the three major ethnic groups studied: African American, Caucasian and Hispanic. For analyses, genotypes were grouped into short (1,1; 1,2; 2,2), short/long (1,3; 2,3; 1,4; 2,4) and long (3,3; 3,4; 4,4) repeats. Deviation from Hardy-Weinberg Equilibrium in the African American control group necessitated testing for association using grouped genotypes rather than grouped alleles. In controls, a significant difference was found in grouped genotype distribution among ethnicities. We found a point-wise, but not experiment-wise across-ethnicities, significant difference in grouped genotype frequency between the cocaine/alcohol-codependent group and the controls in African Americans, with genotypes containing longer alleles found at higher frequency in the codependent group.

Assessment and treatment of pulmonary arterial hypertension: an Australian perspective in 2006

Pulmonary arterial hypertension is a group of diseases which forms a small subset of those with elevated pulmonary artery pressure (pulmonary hypertension). The recent development of selective pulmonary vasodilator has lead to a substantial resurgence of interest in what have been previously regarded as rare and incurable diseases. This review aims to describe the spectrum of pulmonary vascular diseases, the evolving understanding as to pathogenesis, the evolving evidence of efficacy for drug therapies, trying to put this into a contemporary Australian context. Several key pathogenic pathways may be involved: prostacycline, Nitric Oxide-cGMP-phosphodiesterase 5 and endothelin- all of which are exploited for therapeutic benefit by newly available drug therapies. A recently modified classification system reasserts the importance of precise diagnosis. The cardinal symptom of exertional dyspnea warrants careful evaluation in an attempt to prevent (frequently occurring) substantial delay in diagnosis. Echocardiogram is the cornerstone of screening for pulmonary arterial hypertension; however, a detailed evaluation including a carefully performed right heart catheterisation with sufficient data to allow calculation of pulmonary vascular resistance is key to accurate diagnosis. These new approaches to therapy are already substantially improving quality of life and prognosis.

Population of lungs by mast cells

Mast cells are tissue-resident cells that are localized particularly in the skin, gastrointestinal tract and respiratory tract. They are mainly recognised for their role in adaptive immunity and allergy where cross-linking of surface-bound IgE results in acute mediator release giving early symptoms, and cytokine production contributing to chronic changes. The mast cell is now also increasingly recognized for its role in innate immunity conferred by its repertoire of complement and Toll receptors. Thus, mast cell deletion has been shown to suppress certain innate immune responses in murine models. Our interest is in the mechanisms involved in population of tissues by mast cells, particularly the airways. Mast cells are released from the bone marrow into the blood as committed precursors. These cells circulate in very low numbers and accumulate in tissues where they proliferate and mature under the influence of local cytokines and growth factors that define the mature phenotype appropriate for their location. Chemoattraction is important at critical phases in the life history of the mast cell, i.e. movement towards and through the bone marrow sinus endothelium, recruitment to tissues and movement within the tissues to the location of the mature cell. These phases are dependent on chemoattractants generated at specific locations acting on cell surface receptors whose repertoire evolves as the mast cell matures.

Outcomes of patients with interstitial lung disease referred for lung transplant assessment

BACKGROUND

Patients with interstitial lung disease (ILD) very frequently die before the opportunity to receive lung transplantation (LTx). This retrospective study describes the clinical course of 86 patients with ILD referred for LTx assessment between January 1999 and December 2002.

AIMS

(i) To describe the outcomes, (ii) to identify reasons of delay to transplantation, (iii) to describe the causes of death/complications and (iv) to assess the pathological diagnosis and concordance with explanted lung pathology.

METHODS

Data were collected from the case notes of all patients with ILD referred to the Alfred Hospital over a 4-year period.

RESULTS

Twenty women and 66 men, mean age of 55 +/- 8 years, were referred for LTx assessment. Forty-five patients were deemed not suitable for LTx and 41 were listed. Twenty-two patients underwent transplantation, 16 died on the waiting list and 7 are still on the waiting list. Complications were frequent (e.g. pulmonary embolism, malignancy and infection) and carried high mortality. Patients dying on the waiting list appeared generally to be in accelerated decline, dying shortly after listing, with no evidence in their lung function test assessment predicting them as a poor prognosis group.

CONCLUSIONS

Serious complications and death on the waiting list of patients with idiopathic pulmonary fibrosis are high, not apparently because of delayed referral but usually in patients undergoing very rapid decline.

Topical corticosteroid inhibits interleukin-4, -5 and -13 in nasal secretions following allergen challenge

BACKGROUND

Cytokines and chemokines produced by allergen-reactive T-helper type 2 (Th2) cells may be pivotal to the pathophysiology of allergic disorders.

OBJECTIVE

This study was performed to assess the effect of 7 days of topical corticosteroid on nasal allergen challenge (NAC) in terms of eosinophils, cytokines and chemokines obtained by nasal lavage and filter paper methods.

METHODS

Patients with grass pollen seasonal-allergic rhinitis (n = 13) out of season received nasal challenge following matched placebo (twice daily into each nostril for 7 days) and fluticasone propionate (100 microg twice daily into each nostril for 7 days). Chemokine and cytokine levels were analysed using a sensitive automated bead immunoassay system at intervals up to 8 h after NAC.

RESULTS

Levels of cytokines and chemokines from filter paper were generally higher than from nasal lavage. Fluticasone propionate caused a reduction in symptoms, total leukocyte counts and eosinophils, and abrogation of IL-4, IL-5, IL-6 and IL-13 responses in the filter paper taken in the late phase (P < 0.05 for IL-4 and IL-13, P < 0.01 for IL-5 and IL-6). Levels of chemokines (eotaxin, RANTES, MCP-1, MIP-1alpha, IL-8 and IP-10) were also reduced in the late phase (P < 0.01 at 8 h). However, levels of IL-2, IL-3, IL-7, IL-12 (p40 and p70), -15, TNF-alpha, IFN-gamma and GM-CSF were not affected.

CONCLUSION

Fluticasone propionate has selective inhibitory effects on Th2 cytokine synthesis following nasal challenge, while also decreasing release of chemokines, but not affecting levels of Th1 cytokines.

The dynamics and associations of airway neutrophilia post lung transplantation

Bronchoalveolar lavage (BAL) neutrophilia has been repeatedly observed in lung transplant recipients with established bronchiolitis obliterans syndrome (BOS). Little is known of the fluctuations in BAL and airway neutrophilic inflammation post-transplant. This prospective longitudinal study aimed to evaluate the dynamic changes of lung allograft neutrophils with time, immunosuppression, infection and BOS. A total of 28, initially healthy, BOS 0, lung transplant recipients underwent 134 bronchoscopic assessments, including BAL and endobronchial biopsies (EBB) (with immunohistochemistry) over 3-year follow up. Subsequently, 21 developed BOS 0p and 16 ultimately BOS. Compared to controls, there was early and persistent BAL neutrophilia (p < 0.05), contrasting with an initially normal EBB that shows a progressive increased airway wall neutrophil infiltrate. BAL neutrophilia (but not airway wall neutrophilia) was most striking when there was concomitant bronchopulmonary infection, particularly in the patients with BOS. Univariate and multivariate analyses suggested that BAL neutrophilia was linked to markers of infection while EBB neutrophilia was linked with coexistent inflammation with macrophages and lymphocytes.

IN CONCLUSION

(i) BAL neutrophilia is predominantly associated with infection; (ii) Airway wall neutrophilia (as monitored by EBB) increases with time post-transplant and is not associated with infection; (iii) By itself, BOS is not the major contributor to BAL and EBB neutrophilia.

Relation of interlobar collaterals to radiological heterogeneity in severe emphysema

BACKGROUND

A study was undertaken to assess the prevalence of interlobar collateral ventilation in patients with severe emphysema to identify factors that may help to predict patients with significant collateral ventilation.

METHODS

Between April 2002 and August 2003, ex vivo assessment of the lungs 17 consecutive patients with smoking related severe emphysema was performed. To assess collateral flow, all lobes of explanted specimens were selectively intubated using a wedged cuffed microlaryngeal intubation tube and then manually ventilated using a bagging circuit. Interlobar collateral ventilation was defined as the ability to easily inflate a non-intubated lobe at physiological pressures. Pre-transplant demographic characteristics, physiological data, radiological results, and explant histology were assessed for retrospective relationships with the degree of interlobar collateral ventilation in the explanted lung.

RESULTS

A total of 23 lungs were evaluated, 15 of which (66%) had significant collateral interlobar airflow. There were no significant differences in any demographic, physiological, or pathological variables between patients with collateral ventilation and those with no collateral ventilation. However, there was a significant relationship between the presence of interlobar collateral ventilation and radiological scores (p<0.05).

CONCLUSIONS

Interlobar collateral ventilation occurs to a much greater extent in patients with radiologically homogeneous emphysema than in those with heterogeneous emphysema. Heterogeneity of emphysema may predict patients with a significantly reduced risk of interlobar collateral ventilation.

Single dose topical corticosteroid inhibits IL-5 and IL-13 in nasal lavage following grass pollen challenge

BACKGROUND

Nasal lavage is a noninvasive method of obtaining inflammatory exudates following nasal allergen challenge (NAC), and permits cells and released mediators to be evaluated.

OBJECTIVE

To determine the effects of a single dose of topical steroid on eosinophils and levels of chemokines and cytokines in nasal lavage fluid following NAC in patients with allergic rhinitis.

METHODS

Patients with grass pollen seasonal allergic rhinitis (n = 32) out of the allergy season received either nasal budesonide (100 microg per nostril) or matched placebo before allergen challenge in a double blind two-way crossover design. A semi-automated mixed bead array system was employed to measure multiple chemokines and cytokines in small volumes (50 microl) of nasal lavage supernatants.

RESULTS

Following NAC there was a rapid onset of nasal symptoms together with nasal eosinophilia, and the appearance of IL-5 and IL-13 in lavages between 4 and 8 h. Elevated levels of eotaxin, RANTES, IL-8 and MCP-1 were also detected following allergen challenge. A single dose of nasal budesonide caused a decrease in symptoms (P < 0.05) and nasal eosinophils (P < 0.05) with selective abrogation of IL-5 and IL-13 responses (P < 0.05), but a lack of effect on levels of eotaxin, RANTES, IL-8 and MCP-1.

CONCLUSION

This study suggests that a single dose of nasal steroid has the capacity to selectively abolish IL-5 and IL-13 responses following NAC. This model should be convenient for testing novel anti-inflammatory and immunoregulatory agents intended for the treatment of allergic rhinitis.

Selective suppression of leukocyte recruitment in allergic inflammation

Allergic diseases result in a considerable socioeconomic burden. The incidence of allergic diseases, notably allergic asthma, has risen to high levels for reasons that are not entirely understood. With an increasing knowledge of underlying mechanisms, there is now more potential to target the inflammatory process rather than the overt symptoms. This focuses attention on the role of leukocytes especially Th2 lymphocytes that regulate allergic inflammation and effector cells where eosinophils have received much attention. Eosinophils are thought to be important based on the high numbers that are recruited to sites of allergic inflammation and the potential of these cells to effect both tissue injury and remodelling. It is hoped that future therapy will be directed towards specific leukocyte types, without overtly compromising essential host defence responses. One obvious target is leukocyte recruitment. This necessitates a detailed understanding of underlying mechanisms, particularly those involving soluble chemoattractants signals and cell-cell adhesion molecules.

High central venous pressure is associated with prolonged mechanical ventilation and increased mortality after lung transplantation

BACKGROUND

Poor oxygenation might occur in transplanted lungs as a result of reperfusion injury and lack of lymphatic drainage. Low central venous and pulmonary capillary wedge pressures are advocated to reduce pulmonary edema and maximize oxygenation but might adversely affect cardiac index, circulation, and renal function.

METHODS

Histories, intensive care unit charts, and donor data on 118 lung transplantations performed between 1999 and 2002 were retrospectively assessed. Multiple logistic regression analysis was performed on donor, recipient, operative, and intensive care unit parameters to determine the relationship of filling pressure (central venous and pulmonary capillary wedge pressures) to prolonged mechanical ventilation and outcome. The mean central venous pressure was used to divide patients into high and low central venous pressure groups, which were then compared to determine differences in outcome and complication rates.

RESULTS

A high central venous pressure was found to be associated with prolonged mechanical ventilation (odds ratio, 1.57; 95% confidence interval, 1.13-2.20; P = .008). After removing the effect of poor myocardial function by excluding patients with low cardiac index (< 2.2 L x min -1 x m(-2) ) and high inotrope requirement (> 10 microg/min), central venous pressure remained associated with prolonged mechanical ventilation (odds ratio, 2.31; 95% confidence interval, 1.31-4.07; P = .004). Duration of ventilation (P < .001), intensive care unit mortality (P = .02), hospital mortality (P = .09), and 2-month mortality (P = .02) were higher in patients with central venous pressures of greater than 7 mm Hg. There was no evidence of complications caused by hypovolemia in the low (< or = 7 mm Hg) central venous pressure group, who had lower inotrope requirements (P = .02) and lower creatinine levels (P = .013). Conclusions A high central venous pressure was associated with adverse outcomes after lung transplantation.

Non-heart beating organ donation

Increasing the levels of non-heart beating organ donation (NHBOD) is a potential means of improving the supply of transplantable organs. NHBOD may provide a mechanism to enable a patient's prior wishes to be realised and to provide comfort to a family in grief. There is an overriding ethical principle to strictly divide the responsibility for the care of the dying patient and the potential transplant recipient. Medical protocols need to be written, and institutional ethics committees and our national organ procurement system need to be involved if we are to protect public confidence and see NHBOD realise its full potential.

Differential release of MIP-1alpha and eotaxin during infection of mice by Histoplasma capsulatum or inoculation of beta-glucan

OBJECTIVE

In the present study, we evaluated the levels of MIP-1alpha and eotaxin and in vivo migration in the peritoneal cavity model, in mice inoculated with live yeast forms of Histoplasma capsulatum or the beta-glucan cell wall component of this fungus, and the influence of a leukotriene biosynthesis inhibitor, MK886, on the release of these chemokines in relation to cell recruitment.

MATERIALS

Female outbred Swiss mice (N = 4-5 per group, 3-4 wk, were used. Mice were injected i.p. with 1 ml of the 6 x 10(5) live yeast form of the fungus or with 10 microg of beta-glucan from the cell wall fraction, and treated daily with MK886 (1 mg kg(-1), p.o.) or vehicle.

RESULTS

The fungus induced rapid generation of high levels of MIP-1alpha, which remained elevated from 4-48 h whereas very little eotaxin was detected at any time point (Fig. 1A and B). In contrast, the beta-glucan induced a little MIP-1alpha but considerably higher concentrations of eotaxin within the first four hours; however, the level of neither chemokine was sustained (Fig. 2A and B). Treatment of animals with MK886 was effective in reducing the numbers of neutrophils, eosinophils and, to a lesser degree, mononuclear cells accumulating in the peritoneal cavity in response to both the live fungus (Fig. 1C-E) and the cell wall beta-glucan (Fig. 2C-E).

CONCLUSIONS

The results suggest that chemokines and leukotrienes may play key roles in the inflammatory cell influx to H. capsulatum infection or to the inoculation of the beta-glucan cell wall component of this fungus

Bronchodilator reversibility in Australian adults with chronic obstructive pulmonary disease

BACKGROUND AND AIMS

Bronchodilator reversibility (BDR) and inhaled corticosteroid (ICS) use were assessed for volunteers who responded to an advertisement requesting current or ex-smokers who were experiencing breathlessness to attend for lung function testing.

METHODS

One hundred and fifty-four volunteers responded. Forced expiratory volume (FEV1) was measured before and after 400 microg of salbutamol. Significant BDR was assessed according to guidelines of: (i) the American Thoracic Society (> or =12% plus 200 mL of baseline FEV1 or forced vital capacity), (ii) the British-Thoracic Society (BTS) (> or =15% plus 200 mL of baseline FEV1), (iii) the European Thoracic Society (> or =10% predicted FEV1), and (iv) the most commonly used criteria in Australia and New Zealand (> or =15% of baseline FEV1).

RESULTS

One hundred and twenty-three subjects (33 female; 40 current smokers; median pack years 48 (range 5-144)) were suitable for analysis (i.e. had no history of asthma, demonstrable airflow limitation and a forced expiratory ratio (FER) of <70%). Twenty (16%) patients had an FEV1 within the normal range but FER of <70%, 24 (20%) patients had mild disease (FEV1 60-80% predicted), 31 (24%) patients had moderate disease (FEV1 40-59% predicted), and 48 (39%) patients had severe disease (FEV1 <40% predicted), according to BTS criteria. Significant BDR was evident in: (i) 58 (47%) subjects by American criteria, (ii) 26 (21%) subjects by British criteria, (iii) 19 (15%) subjects by European criteria and (iv) 36 (29%) subjects by Australasian criteria. ICS use was reported by 71 (58%) subjects overall and was weakly, but significantly, related to poorer FEV1 (r = -0.2; P < 0.01), and greater BDR (r = 0.3; P < 0.005).

CONCLUSION

Chronic obstructive pulmonary disease in Australian volunteers with no history of asthma encompasses many individuals with significant BDR. Interestingly, most volunteers reported ICS use and this was related to poorer spirometry and greater BDR. However, until the underlying immuno-pathology has been determined they cannot be assumed to have "asthma" or even an "asthmatic element".

Effect of inhaled fluticasone propionate on BAL TGF-β1 and bFGF concentrations in clinically stable lung transplant recipients

BACKGROUND

Inhaled fluticasone propionate (FP) therapy decreases inflammation and sub-basement membrane thickness in asthmatic airways. Bronchiolitis obliterans syndrome (BOS) in lung transplant recipients (LTRs) involves progressive airway fibrosis and obliteration. Therefore, augmented immunosuppression may be of some benefit in treating BOS. In this study, we examined the effect of 3 months of treatment with high-dose inhaled FP on the concentrations of 2 fibrogenic factors, transforming growth factor (TGF)-beta(1) and beta fibrogenic growth factor (bFGF) in bronchoalveolar lavage (BAL) fluid from clinically stable LTRs.

METHODS

We conducted a randomized, double-blind, placebo-controlled, parallel group study with inhaled FP (750 microg, twice/day for 3 months) in 28 LTRs (15 FP and 13 placebo). We recruited 23 healthy controls. We performed spirometry, bronchoscopy, and bronchoalveolar lavage procedures before treatment and after 3 months of treatment. We used commercially available enzyme-linked immunosorbent assay kits to measure BAL fluid TGF-beta(1) and bFGF concentrations.

RESULTS

In LTRs before treatment, BAL TGF-beta(1) concentrations (but not bFGF concentrations), total cell counts, and neutrophil percentage increased compared with controls (p < 0.05). We found no significant differences between FP and placebo groups at baseline measurements. After treatment, BAL TGF-beta(1) concentrations significantly increased in the FP group (p = 0.03), but we found no difference between FP and placebo groups; BAL bFGF concentrations increased during treatment in both groups compared with controls (p < 0.05), but not significantly within either patient group (p > 0.05). We found a reverse correlation between forced expiratory volume in 1 second (FEV(1)) and BAL TGF-beta(1) concentration in the FP group (r = -0.53, p = 0.04), and between FEV(1) and BAL TGF-beta(1) concentration in the placebo group (r = -0.74, p = 0.004). Multivariable analysis indicated no significant independent effects of inhaled FP in either BAL TGF-beta(1) or bFGF concentrations.

CONCLUSIONS

Bronchoalveolar fluid TGF-beta(1) concentrations increased in LTRs after transplantation and may correlate with the decrease in lung function. Inhaled FP added to conventional immunosuppression had no effect on TGF-beta(1) or bFGF production in BAL fluid.

Pharmacological characteristics of Ro 115-1240, a selective alpha1A/1L-adrenoceptor partial agonist: a potential therapy for stress urinary incontinence

OBJECTIVE

To describe the preclinical pharmacology of Ro 115-1240, a peripherally acting selective alpha1A/1L-adrenoceptor (AR) partial agonist, compared with the alpha1A/1L-AR full agonist amidephrine, as AR agonists have some utility in the treatment of stress urinary incontinence (SUI) but are limited by undesirable cardiovascular and central nervous system side-effects.

RESULTS

In radioligand-binding studies Ro 115-1240 had greater affinity for alpha1A than for alpha1B and alpha1D subtypes. The potency and intrinsic activity of amidephrine and Ro 115-1240 relative to noradrenaline were determined in native and cell-based assays using human recombinant alpha1-ARs; they acted as selective alpha1A/1L-AR full and partial agonists, respectively. In anaesthetized micropigs and rabbits, amidephrine and Ro 115-1240 produced non-selective, dose-dependent increases in intraurethral and arterial blood pressures but the magnitude of the pressure increases evoked by Ro 115-1240 were about a third of those with amidephrine. In conscious micropigs both agents produced dose-dependent increases in urethral tension. Again, the magnitude of the urethral response to Ro 115-1240 was about a third of that with amidephrine. More importantly, only amidephrine produced dose-dependent increases in blood pressure and decreases in heart rate. Ro 115-1240 produced a maximum increase in urethral tension with no effect on blood pressure or heart rate.

CONCLUSION

These results show that by combining selectivity for the alpha1A/1L-AR subtype with a reduction in intrinsic agonist efficacy, Ro 115-1240 has reduced haemodynamic effects while retaining to some degree the contractile effects on urethral smooth muscle. These studies indicate that Ro 115-1240 may be useful as a novel treatment for SUI.

Eotaxin receptor (CCR3) antagonism in asthma and allergic disease

A range of low molecular weight chemicals have been developed to antagonise the eotaxin receptor, cysteine-cysteine chemokine receptor-3 (CCR3), with the aim of selectively inhibiting eosinophil recruitment into tissue sites. However, the results of recent clinical trials with monoclonal antibodies directed against interleukin-5 (IL-5) question the role of eosinophils in mediating the symptoms of asthma and allergic disease. For this reason, the plans for clinical development of certain CCR3 antagonists have been halted. However, eotaxin 1-3 and a variety of other chemokines interact with CCR3; and this receptor is expressed not only on eosinophils but also on basophils, mast cell subpopulations, activated Th2 cells, macrophages, and airway epithelial cells. Hence, CCR3 is closely associated with asthma and allergy and blockade of this receptor may have pronounced beneficial effects in these diseases. We consider the chemical structures of CCR3 antagonist molecules from a range of pharmaceutical companies, and present an early clinical development plan for a hypothetical CCR3 antagonist. CCR3 antagonists are likely to be safe and effective therapies for allergic diseases, and their clinical pharmacology can readily be defined within phase I/II studies in patients with allergy and asthma.

Synthesis, pharmacology and pharmacokinetics of 3-(4-aryl-piperazin-1-ylalkyl)-uracils as uroselective alpha1A-antagonists

Predominance in the urethra and prostate of the alpha(1A)-adrenoceptor subtype, which is believed to be the receptor mediating noradrenaline induced smooth muscle contraction in these tissues, led to the preparation of alpha(1A)-selective antagonists to be tested as uroselective compounds for the treatment of benign prostatic hyperplasia. Thus, a number of selective alpha(1A)-adrenoceptor antagonists were synthesized and assayed in vitro for potency and selectivity. Dog pharmacokinetic parameters of 12 (RO700004) and its metabolite 40 (RO1104253) were established. The relative selectivity of intravenously administered 12, 40 and standard prazosin to inhibit hypogastric nerve stimulation-induced increases in intraurethral prostatic pressure versus phenylephrine-induced increases in diastolic blood pressure in anesthetized dogs was 76, 71 and 0.6, respectively.

Testosterone regulates terminal Schwann cell number and junctional size during developmental synapse elimination

Previous work has shown that exposure to exogenous testosterone during synapse elimination permanently stabilizes synapses that would normally be lost in the androgen-sensitive levator ani (LA) muscle, indicating that testosterone is a potent stabilizing factor for developing LA synapses. Terminal Schwann cells (TSCs), which cap the neuromuscular junction, have also been implicated in the control of synaptic stability and may play a decisive role in the selective stabilization of synapses during synapse elimination. In this study, we begin to investigate the possible role of TSCs in the effect of testosterone on synapse elimination by determining whether testosterone influences their number. As the number of TSCs generally correlates with the size of endplates, we also measured endplate size. Male rats were castrated or sham gonadectomized at postnatal day (P) 7 and given capsules containing either testosterone or nothing. Three weeks later (P27-28), LA neuromuscular junctions (NMJs) were stained using immune and nonimmune markers. As expected, testosterone treatment during synapse elimination maintained synapses that would ordinarily be eliminated. In addition, we find that the size of LA endplates and the number of TSCs per LA junction were also increased by the testosterone treatment. However, testosterone significantly increased the number of TSCs on both singly and multiply innervated fibers, indicating that the effect of testosterone on the number of TSCs is not specific to its effect on synapse maintenance. Rather the testosterone-induced increase in the number of TSCs appears related to the size of LA NMJs, a relationship that has precedence.

Increased soluble CD14 in bronchoalveolar lavage fluid of stable lung transplant recipients

Macrophages, neutrophils and infection have been implicated in the genesis of the bronchiolitis obliterans syndrome (BOS) post lung transplantation. sCD14 is a soluble form of a shed-cell surface protein. It is capable of promoting cytokine-induced inflammation and it's presence in clinically stable lung transplant recipients (LTR) might be important as an early marker of BOS. Bronchalveolar lavage (BAL) and blood samples were taken from 26 stable LTR, at or near their best forced expiratory volume in one second who were free from infection. sCD14 levels were measured via enzyme-linked immunosorbent assay. Cell counts were performed on unfiltered BAL. LTR neutrophil count, BAL sCD14 and serum sCD14 levels were higher than controls (median 3.8% versus 1.3%, p<0.05; 11.5 ng x mL(-1) versus 6 ng x mL(-1), p<0.001; 6.2 microg x mL(-1) versus 2.4 microg x mL(-1), p<0.05, respectively). BAL albumin and sCD14 correlated (regression coefficient: 0.77, p<0.001). In this hypothesis-generating, cross-sectional study, the authors have described for the first time soluble CD14 levels in the bronchoalveolar lavage and serum of stable lung transplant recipients, and show that these are elevated compared to controls. This is a practicable candidate marker system, which can be tested for a predictive role in bronchiolitis obliterans syndrome following lung transplantation. The origin of this cellular protein and its temporal relationship to the development of the bronchiolitis obliterans syndrome remains to be elucidated in more definitive longitudinal studies, which should include other measurements potentially relevant to the innate immune system, such as bronchoalveolar lavage endotoxin levels.