Complete genome sequence of Pseudomonas aeruginosa PAO1, an opportunistic pathogen

Pseudomonas aeruginosa is a ubiquitous environmental bacterium that is one of the top three causes of opportunistic human infections. A major factor in its prominence as a pathogen is its intrinsic resistance to antibiotics and disinfectants. Here we report the complete sequence of P. aeruginosa strain PAO1. At 6.3 million base pairs, this is the largest bacterial genome sequenced, and the sequence provides insights into the basis of the versatility and intrinsic drug resistance of P. aeruginosa. Consistent with its larger genome size and environmental adaptability, P. aeruginosa contains the highest proportion of regulatory genes observed for a bacterial genome and a large number of genes involved in the catabolism, transport and efflux of organic compounds as well as four potential chemotaxis systems. We propose that the size and complexity of the P. aeruginosa genome reflect an evolutionary adaptation permitting it to thrive in diverse environments and resist the effects of a variety of antimicrobial substances.

Care homes' use of medicines study: prevalence, causes and potential harm of medication errors in care homes for older people

INTRODUCTION

Care home residents are at particular risk from medication errors, and our objective was to determine the prevalence and potential harm of prescribing, monitoring, dispensing and administration errors in UK care homes, and to identify their causes.

METHODS

A prospective study of a random sample of residents within a purposive sample of homes in three areas. Errors were identified by patient interview, note review, observation of practice and examination of dispensed items. Causes were understood by observation and from theoretically framed interviews with home staff, doctors and pharmacists. Potential harm from errors was assessed by expert judgement.

RESULTS

The 256 residents recruited in 55 homes were taking a mean of 8.0 medicines. One hundred and seventy-eight (69.5%) of residents had one or more errors. The mean number per resident was 1.9 errors. The mean potential harm from prescribing, monitoring, administration and dispensing errors was 2.6, 3.7, 2.1 and 2.0 (0 = no harm, 10 = death), respectively. Contributing factors from the 89 interviews included doctors who were not accessible, did not know the residents and lacked information in homes when prescribing; home staff's high workload, lack of medicines training and drug round interruptions; lack of team work among home, practice and pharmacy; inefficient ordering systems; inaccurate medicine records and prevalence of verbal communication; and difficult to fill (and check) medication administration systems.

CONCLUSIONS

That two thirds of residents were exposed to one or more medication errors is of concern. The will to improve exists, but there is a lack of overall responsibility. Action is required from all concerned.

Male breast carcinoma: a review of 229 patients who presented to the Princess Margaret Hospital during 40 years: 1955-1996

BACKGROUND

A single-institution review of clinical presentation, treatment, and outcome of male breast carcinoma was conducted.

METHODS

Data obtained by chart review of 229 cases were analyzed with respect to clinical presentation, treatment choice, significant prognostic factors, and survival. The patients were analyzed both as a single cohort and as four cohorts grouped according to decade of diagnosis.

RESULTS

Presentation occurred at a median age of 63 years, most often with a self-detected lump. Pathology consisted of subtypes similar to those of female breast carcinoma. The majority of tumors were larger than 2 cm in greatest dimension. Lymph node status, hormone receptors, and histologic and nuclear grade were underreported. Primary, adjuvant, and advanced disease treatment practices were reviewed over time. The 5-year disease free survival (DFS), overall survival (OS), and local control were 47%, 53%, and 91%, respectively. No difference in outcome by decade of diagnosis was observed. Negative lymph nodes and adjuvant hormone treatment predicted for better DFS and OS. Younger age and Stage 0 also predicted for better OS.

CONCLUSIONS

Compared with data from female breast carcinoma patients, 5-year OS for this series was low; however, when these patients were separated by lymph node status, survival was similar for those with axillary lymph node metastases. Despite a change in standard primary surgical treatment and an increased use of chemotherapy and hormone therapy over the study period, no difference in outcome was observed among these males. In the absence of prospective, randomized clinical trials, collection of comprehensive data on the presentation and management of male breast carcinoma may help to optimize clinical care.

Quality of life in schizophrenia: contributions of anxiety and depression

A number of studies have demonstrated a strong relationship between quality of life in schizophrenia and general psychopathology measures, and moreover, that the positive, negative, and disorganized symptoms are less related to quality of life. The current investigation examined the relationship between quality of life and symptomatology in 63 stabilized outpatients diagnosed with schizophrenia or schizoaffective disorder. Consistent with other findings, more severe depression, as rated on the Brief Psychiatric Rating Scale (BPRS) was associated with lower general life satisfaction and lower satisfaction with daily living, finances, health, and social life. In addition, higher anxiety ratings on the BPRS were associated with less satisfaction with global quality of life, daily activities, family, health and social relationship, even when controlling for positive symptoms, negative symptoms, or depression. No other symptoms of schizophrenia were as strongly associated with subjective quality of life. Anxiety was also significantly correlated with a number of positive and negative symptoms while depression was substantially less related. These findings, suggest that more precise analyses of general psychopathology, and anxiety in particular, may be necessary to further clarify the factors involved in quality of life in schizophrenia. In addition, these findings suggest future directions for theories of affect and treatment in schizophrenia.

Rat astrocytes and Schwann cells in culture synthesize nerve growth factor-like neurite-promoting factors

Neurite-promoting activity in feeding medium conditioned by rat astrocytes and Schwann cells in culture was examined. The conditioned medium (CM) from both types of glial cultures stimulated extensive neurite outgrowth from embryonic chick dorsal root ganglia (DRG) as well as pheochromocytoma (PC12) cells. Both the DRG and PC12 cells also produce neurite outgrowth in the presence of nerve growth factor (NGF). With the DRG, the neurite growth rates observed with the glial cell CM were identical to growth rates seen with NGF. Although anti-NGF antibody did not inhibit the neurite outgrowth produced by either of the glial CM, a nerve growth factor radioreceptor assay did detect an NGF-like molecule in both CM. Since the extensive neurite outgrowth stimulated by the glial CM was not mimicked by pure laminin alone, we conclude that the glial neurite promoting factors are distinct from laminin.

From adaptive licensing to adaptive pathways: delivering a flexible life-span approach to bring new drugs to patients

The concept of adaptive licensing (AL) has met with considerable interest. Yet some remain skeptical about its feasibility. Others argue that the focus and name of AL should be broadened. Against this background of ongoing debate, we examine the environmental changes that will likely make adaptive pathways the preferred approach in the future. The key drivers include: growing patient demand for timely access to promising therapies, emerging science leading to fragmentation of treatment populations, rising payer influence on product accessibility, and pressure on pharma/investors to ensure sustainability of drug development. We also discuss a number of environmental changes that will enable an adaptive paradigm. A life-span approach to bringing innovation to patients is expected to help address the perceived access vs. evidence trade-off, help de-risk drug development, and lead to better outcomes for patients.

Actinomycin D blocks formation of memory of shock-avoidance in goldfish

When 2 micrograms of antinomycin D was injected intracranially into goldfish immediately after a training session, the formation of long-term memory of a shock-avoidance was blocked. The results are discussed in relation to similar findings with acetoxycycloheximide and puromycin in the goldfish and with apparently conflicting results in the mouse.

Purification and characterization of glia maturation factor beta: a growth regulator for neurons and glia

A protein has been isolated from bovine brains by using a modification of the procedure used to purify glia maturation factor. The method consists of ammonium sulfate precipitation, chromatography with DEAE-Sephacel, Sephadex G-75, and hydroxylapatite columns, passage through a heparin-Sepharose column, and finally fractionation by reverse-phase HPLC with a C4 column. The isolated protein reacts strongly with the mouse monoclonal antibody G2-09 and has a molecular weight of approximately 17,000 and an isoelectric point of pH 4.9. The N terminus is blocked, but tryptic digestion releases 28 peptides, 8 of which have been sequenced. The total known residues add up to more than two-thirds of the entire 140-residue protein, estimated from amino acid composition, and show no sequence homology with any known protein. Reversible thermal renaturation greatly enhances its biological activity. The purified protein stimulates differentiation of normal neurons as well as glial cells. It inhibits the proliferation of the N-18 neuroblastoma line and the C6 glioma line while promoting their phenotypic expression. We designate this protein glia maturation factor beta.

Brain cells in culture: morphological transformation by a protein

One type of elmbryonic rat brain cell having an epithelioid morphology in the monolayer culture can be transformed by brain extract into cells having extensive processes resembling mature astrocytes. The transforming factor is a protein with a molecular weight of 350,000. A partially purified sample showed that it is active at a concentration as low as 1 x 10(-8)M. The transforming actvity is high in adult brains but low in embryonic brains and tumors of the nervous systems.

Early release of glia maturation factor and acidic fibroblast growth factor after rat brain injury

A major component of the healing response of the brain to injury is the induction of growth and trophic factors. In the rat brain, glia maturation factor (GMF) and acidic fibroblast growth factor (aFGF) are not extracellular. However, within the first hour following brain injury, the amount of GMF and aFGF in the wound cavity increased by 7- and 13-fold, respectively, compared to the tissue adjacent to the wound. A cascade of cellular and biochemical events, leading to glial proliferation, the arrest of secondary neuronal death and axonal sprouting, may be initiated by the sudden increase in the extracellular concentration of these factors.

Developmental changes in EPSC quantal size and quantal content at a central glutamatergic synapse in rat

1. Developmental changes in amplitude and time course of single-fibre-evoked and spontaneous EPSCs mediated by AMPA and NMDA receptors at the endbulb-bushy cell synapse of rats from 4 to 22 days of age were recorded using whole-cell patch-clamp methods in in vitro slices of cochlear nucleus. 2. The mean conductance of the AMPA component of evoked EPSCs increased by 66 %, while that of the NMDA component decreased by 61 %, for 12- to 18-day-old rats cf. 4- to 11-day-old rats. 3. The mean AMPA spontaneous EPSC conductance increased by 54 %, while mean NMDA spontaneous EPSC conductance decreased by 83 %, for 12- to 22-day-old rats cf. 4- to 11-day-old rats. The mean number of quanta contributing to peak evoked AMPA conductance also increased by 78 % in the older age group, after correction for the asynchrony of evoked quantal release. 4. The decay time constant of spontaneous AMPA EPSCs showed a small decrease in older animals, while the decay time constant of spontaneous NMDA EPSCs was markedly decreased in older animals. The decay time constants of evoked NMDA EPSCs showed a quantitatively similar decrease to that of spontaneous NMDA EPSCs. This suggests that AMPA receptor subunit composition is unlikely to undergo developmental change, while NMDA receptor subunit composition may be substantially altered during synaptic maturation. 5. These data are consistent with a developmentally increased efficacy of AMPA receptor-mediated synaptic transmission at the endbulb-bushy cell synapse, due to an increase in underlying AMPA-mediated quantal size and content during the same period as a transient co-localization of NMDA receptors.

Molecular cloning and expression of biologically active human glia maturation factor-beta

Glia maturation factor-beta, a protein found in the brains of all vertebrates thus far examined, appears to play a role in the differentiation, maintenance, and regeneration of the nervous system. Using oligonucleotide probes based on the sequences of three tryptic peptides derived from bovine glia maturation factor-beta, we screened a human brainstem cDNA library in lambda gt11. A 0.7-kb clone was isolated, sequenced in its entirety, and found to encode a polypeptide of 142 amino acids which contained regions identical to the three bovine peptides. This polypeptide, human recombinant glia maturation factor-beta, has been expressed in Escherichia coli and found to possess structural characteristics and biological activity indistinguishable from those of the native bovine protein.

GABA mediates presynaptic inhibition at glycinergic synapses in a rat auditory brainstem nucleus

Many inhibitory nerve terminals in the mammalian anteroventral cochlear nucleus (AVCN) contain both glycine and GABA, but the reason for the co-localization of these two inhibitory neurotransmitters in the AVCN is unknown. We have investigated the roles of glycine and GABA at synapses on bushy cells in the rat AVCN, using receptor immunohistochemistry and electrophysiology. Our immunohistochemical results show prominent punctate labelling of postsynaptic clusters of glycine receptors and of the receptor clustering protein gephyrin over the surface of bushy cells. In contrast, weak diffuse membrane immunolabelling of GABAA receptors was observed. Whole-cell recordings from bushy cells in AVCN slices demonstrated that evoked inhibitory postsynaptic currents (IPSCs) were predominantly (81 %) glycinergic, based on the decrease in amplitude of the IPSCs in bicuculline (10 microM). This observation was supported by the effect of strychnine (1 microM), which was to decrease the evoked IPSC (to 10 % of control IPSC amplitude) and to produce a greater than 90 % block of spontaneous miniature IPSCs. These results suggest a minor role for postsynaptic GABAA receptors in bushy cells, despite a high proportion of GABA-containing terminals on these cells. Therefore, a role for metabotropic GABAB receptors was investigated. Activation of GABAB receptors with baclofen revealed a significant attenuation of evoked glycinergic IPSCs. The effect of baclofen was presynaptic, as indicated by a lack of change in the mean amplitude of spontaneous IPSCs. Significantly, the decrease in the amplitude of evoked glycinergic IPSCs observed following repetitive nerve stimulation was reduced in the presence of the GABAB antagonist, CGP 35348. This indicates that synaptically released GABA can activate presynaptic GABAB receptors to reduce transmitter release at glycinergic synapses. Our results suggest specific pre- versus postsynaptic physiological roles for GABA and glycine in the AVCN.

Glia maturation factor: effect on chemical differentiation of glioblasts in culture

A protein factor from the adult brain increases the concentrations of adenosine 3',5'-monophosphate and S-100 protein in glioblasts in culture. Such changes are correlated with the outgrowth of cell processes.

A novel role of glia maturation factor: induction of granulocyte-macrophage colony-stimulating factor and pro-inflammatory cytokines

The glia maturation factor (GMF), which was discovered in our laboratory, is a highly conserved protein predominantly localized in astrocytes. GMF is an intracellular regulator of stress-related signal transduction. We now report that the overexpression of GMF in astrocytes leads to the destruction of primary oligodendrocytes by interactions between highly purified cultures of astrocytes, microglia, and oligodendrocytes. We infected astrocytes with a replication-defective adenovirus carrying the GMF cDNA. The overexpression of GMF caused the activation of p38 MAP kinase and transcription factor NF-kappaB, as well as the induction of granulocyte-macrophage colony-stimulating factor (GM-CSF) mRNA and protein in astrocytes. Small interfering RNA-mediated GMF knockdown completely blocked the GMF-dependent activation of p38 mitogen-activated protein kinase (MAPK), NF-kappaB, and enhanced expression of GM-CSF by astrocytes. Inhibition of p38 MAPK or NF-kappaB by specific inhibitors prevented GM-CSF production. The cell-free conditioned medium from overexpressing GMF astrocytes contained 320 +/- 33 pg/mL of GM-CSF, which was responsible for enhanced production and secretion of TNF-alpha, IL-1beta, IL-6, and IP-10 by microglia. Presence of these inflammatory cytokines in the conditioned medium from microglia efficiently destroyed oligodendrocytes in culture. These results suggest that GMF-induced production of GM-CSF in astrocytes is depending on p38 MAPK and NF-kappaB activation. The GM-CSF-dependent expression and secretion of inflammatory cytokine/chemokine, TNF-alpha, IL-1beta, IL-6, and IP-10, is cytotoxic to oligodendrocytes, the myelin-forming cells in the central nervous system, and as well as neurons. Our results suggest a novel pathway of GMF-initiated cytotoxicity of brain cells, and implicate its involvement in inflammatory diseases such as multiple sclerosis.

Deubiquitinase USP10 regulates Notch signaling in the endothelium

Notch signaling is a core patterning module for vascular morphogenesis that codetermines the sprouting behavior of endothelial cells (ECs). Tight quantitative and temporal control of Notch activity is essential for vascular development, yet the details of Notch regulation in ECs are incompletely understood. We found that ubiquitin-specific peptidase 10 (USP10) interacted with the NOTCH1 intracellular domain (NICD1) to slow the ubiquitin-dependent turnover of this short-lived form of the activated NOTCH1 receptor. Accordingly, inactivation of USP10 reduced NICD1 abundance and stability and diminished Notch-induced target gene expression in ECs. In mice, the loss of endothelial Usp10 increased vessel sprouting and partially restored the patterning defects caused by ectopic expression of NICD1. Thus, USP10 functions as an NICD1 deubiquitinase that fine-tunes endothelial Notch responses during angiogenic sprouting.

Quantal size is correlated with receptor cluster area at glycinergic synapses in the rat brainstem

1. Whole-cell patch electrode recordings of glycinergic miniature inhibitory postsynaptic currents (mIPSCs) were obtained in neurons of the rat anteroventral cochlear nucleus (AVCN). Mean mIPSC peak amplitude was found to vary considerably between AVCN neurons (range, -19.1 to -317.9 pA; mean +/- s.d., -159.1 +/- 100.7 pA; 14 cells). 2. Immunolabelling of glycinergic receptor clusters in AVCN neurons was performed using antibodies against the glycine receptor clustering protein gephyrin. Measurements of the area of gephyrin immunoreactive clusters were obtained using confocal fluorescence microscopy. These measurements showed a large variability in cluster area, not only in the same cell (mean coefficient of variation, c.v., 0.66 +/- 0.18; 16 cells), but also in mean cluster area between cells (range, 0.21-0.84 microm2; 16 cells). 3. A possible relationship between mIPSC amplitude and receptor cluster area was investigated in a further series of experiments, in which mIPSCs recordings and immunolabelling of glycine receptor clusters were obtained for the same cells. In these experiments, AVCN neurons were identified using intracellular labelling with neurobiotin. Successful results using a combination of whole-cell recordings, neurobiotin identification and immunolabelling were obtained for a total of 10 AVCN neurons. Analysis of the results revealed a positive, statistically significant correlation between mean receptor cluster size and mean mIPSC amplitude (P < 0.05, 10 cells, Spearman's correlation test). 4. These results provide direct experimental evidence supporting a hypothesis of central glycinergic transmission in which synaptic strength may be regulated by changes in the size of the postsynaptic receptor region.

Prospective audit and feedback on antibiotic prescription in an adult hematology-oncology unit in Singapore

We evaluated the impact of a prospective audit and feedback antimicrobial stewardship program (ASP) on antibiotic prescription and resistance trends in a hematology-oncology unit in a university hospital (National University Cancer Institute, Singapore [NCIS]). A prospective interrupted time-series study comprising 11-month pre-intervention (PIP) and intervention evaluation phases (IEP) flanking a one-month implementation phase was carried out. Outcome measures included defined daily dose per 100 (DDD/100) inpatient-days of ASP-audited and all antibiotics (encompassing audited and non-audited antibiotics), and the incidence-density of antibiotic-resistant microorganisms at the NCIS. Internal and external controls were DDD/100 inpatient-days of paracetamol at the NCIS and DDD/100 inpatient-days of antibiotics prescribed in the rest of the hospital. There were 580 ASP recommendations from 1,276 audits, with a mean monthly compliance of 86.9%. Significant reversal of prescription trends towards reduced prescription of audited (coefficient = -2.621; 95% confidence interval [CI]: -4.923, -0.319; p = 0.026) and all evaluated antibiotics (coefficient = -4.069; 95% CI: -8.075, -0.063; p = 0.046) was observed. No changes were seen for both internal and external controls, except for the reversal of prescription trends for cephalosporins hospital-wide. Antimicrobial resistance did not change over the time period of the study. Adverse outcomes-the majority unavoidable-occurred following 5.5% of accepted ASP recommendations. Safe and effective ASPs can be implemented in the complex setting of hematology-oncology inpatients.

Expression of glia maturation factor beta mRNA and protein in rat organs and cells

Rat glia maturation factor beta (GMF-beta) cDNA was obtained by reverse transcription of rat brain mRNA followed by polymerase chain reaction amplification, using primers from the human sequence. The deduced amino acid sequence of rat GMF-beta differed from the human counterpart in only three places: His27 in place of Asn, Val51 in place of Ile, and Leu93 in place of Val. The high degree of evolutionary conservation suggests that GMF-beta plays an essential role in animal cell physiology. The expression of GMF-beta mRNA in the rat was studied by the northern blot technique, using a rat cRNA probe corresponding to the entire coding region. GMF-beta mRNA was predominantly expressed in the brain and spinal cord, although trace levels were found in other organs, including testis and ovary. In the brain GMF-beta mRNA was detectable at as early as embryonic day 10, and persisted through as late as postnatal month 14, with minor variations in between. On the other hand, GMF-beta protein exhibited more obvious developmental changes, with its level increasing slowly prenatally and plateauing at 1 week after birth. GMF-beta mRNA and protein were also observed in several cultured cells. Some cells of neural origin contained higher levels of GMF-beta protein compared with cells derived from other sources. Through demonstration of mRNA and confirmation by immunoblotting, we conclude that GMF-beta is synthesized by rat organs and that GMF-beta is predominantly a brain protein.