BACKGROUND

In propensity score modeling, it is a standard practice to optimize the prediction of exposure status based on the covariate information. In a simulation study, we examined in what situations analyses based on various types of exposure propensity score (EPS) models using data mining techniques such as recursive partitioning (RP) and neural networks (NN) produce unbiased and/or efficient results.

METHODS

We simulated data for a hypothetical cohort study (n = 2000) with a binary exposure/outcome and 10 binary/continuous covariates with seven scenarios differing by non-linear and/or non-additive associations between exposure and covariates. EPS models used logistic regression (LR) (all possible main effects), RP1 (without pruning), RP2 (with pruning), and NN. We calculated c-statistics (C), standard errors (SE), and bias of exposure-effect estimates from outcome models for the PS-matched dataset.

RESULTS

Data mining techniques yielded higher C than LR (mean: NN, 0.86; RPI, 0.79; RP2, 0.72; and LR, 0.76). SE tended to be greater in models with higher C. Overall bias was small for each strategy, although NN estimates tended to be the least biased. C was not correlated with the magnitude of bias (correlation coefficient [COR] = -0.3, p = 0.1) but increased SE (COR = 0.7, p < 0.001).

CONCLUSIONS

Effect estimates from EPS models by simple LR were generally robust. NN models generally provided the least numerically biased estimates. C was not associated with the magnitude of bias but was with the increased SE.

OBJECTIVE

The symptoms of postprandial distress syndrome (PDS) and epigastric pain syndrome (EPS), the two subtypes of functional dyspepsia (FD) under the new Rome III classification, tend to overlap with those of non-erosive reflux disease (NERD). Plasma ghrelin levels have been associated with gastric motility; however, clinical studies have yet to examine this relationship among patients with PDS, EPS or NERD. Thus, this study aims to evaluate the correlation between gastric emptying and ghrelin levels as possible candidate factors for gastric motility in these diseases.

METHODS

One hundred and fifty-one patients presenting with typical symptoms of FD (EPS, n = 36; PDS, n = 76) or NERD (n = 39), and 20 healthy volunteers were enrolled. Gastric motility was evaluated with the T(max) value as a marker of gastric emptying using the 13C-acetate breath test. We used Rome III criteria to evaluate upper abdominal symptoms, and SRQ-D scores to determine depression status. We measured both acylated and des-acylated ghrelin levels by ELISA methods.

RESULTS

The Tmax value in PDS patients was significantly higher than in healthy volunteers. Acylated ghrelin levels were significantly lower in NERD and PDS patients than in healthy volunteers. Interestingly, there was significant correlation between the acylated ghrelin levels and Tmax value in PDS patients but not in EPS or NERD patients.

CONCLUSIONS

Our results suggest that acylated ghrelin might play an important role in the pathophysiology of PDS patients through its effect on gastric emptying.

The type I protein secretion system of Rhizobium leguminosarum bv. viciae encoded by the prsD and prsE genes is responsible for secretion of the exopolysaccharide (EPS)-glycanases PlyA and PlyB. The formation of a ring of biofilm on the surface of the glass in shaken cultures by both the prsD and prsE secretion mutants was greatly affected. Confocal laser scanning microscopy analysis of green-fluorescent-protein-labeled bacteria showed that during growth in minimal medium, R. leguminosarum wild type developed microcolonies, which progress to a characteristic three-dimensional biofilm structure. However, the prsD and prsE secretion mutants were able to form only an immature biofilm structure. A mutant disrupted in the EPS-glycanase plyB gene showed altered timing of biofilm formation, and its structure was atypical. A mutation in an essential gene for EPS synthesis (pssA) or deletion of several other pss genes involved in EPS synthesis completely abolished the ability of R. leguminosarum to develop a biofilm. Extracellular complementation studies of mixed bacterial cultures confirmed the role of the EPS and the modulation of the biofilm structure by the PrsD-PrsE secreted proteins. Protein analysis identified several additional proteins secreted by the PrsD-PrsE secretion system, and N-terminal sequencing revealed peptides homologous to the N termini of proteins from the Rap family (Rhizobium adhering proteins), which could have roles in cellular adhesion in R. leguminosarum. We propose a model for R. leguminosarum in which synthesis of the EPS leads the formation of a biofilm and several PrsD-PrsE secreted proteins are involved in different aspects of biofilm maturation, such as modulation of the EPS length or mediating attachment between bacteria.

CD4, the T cell surface antigen, is phosphorylated and internalized when T cells are activated or treated with a phorbol ester, PMA. The actual phosphorylation sites have been identified and the role of phosphorylation of each on CD4 internalization investigated. Seven different mutants, in each of which one, two or all three of the serine residues of the cytoplasmic region was modified to alanine(s) (CD4.SA mutants) and one mutant in which the whole amino acid sequence from Gln421 to the C-terminal Ile433 was changed (CD4.EP mutant) were constructed and used to determine the effect of phosphorylation on CD4 internalization. Ser408 was the most efficiently phosphorylated by PMA treatment, Ser415 next and Ser431 to a minor extent. The effect of mutation on internalization was well matched with the effect on extent of phosphorylation, i.e. Ser408 was the residue most important for internalization. However, complete inhibition of CD4 internalization was achieved only by mutating all three serine residues. Interestingly, the mutant CD4.EP in which Ser408 was present and phosphorylated was not measurably internalized, suggesting that phosphorylation of Ser408 induces CD4 internalization only when other structural features of the cytoplasmic domain remain intact. In addition, the data suggest the existence of an additional minor pathway for CD4 internalization which is phosphorylation independent.

Bispecific T-cell engager (BiTE) are a class of bispecific single-chain antibodies that can very effectively redirect cytotoxic T cells for killing of tumor target cells. Here, we have assessed the in vivo efficacy of one representative, called bscEp-CAMxCD3, with specificity for tumors overexpressing epithelial cell adhesion molecule (Ep-CAM) in human xenograft models. Cells of the human colon carcinoma line SW480 were mixed at a 1:1 ratio with unstimulated human peripheral mononuclear cells, s.c. injected in nonobese diabetes/severe combined immunodeficiency (NOD/SCID) mice, and animals were treated with bscEp-CAMxCD3. Five daily i.v. injections of as little as 100 ng per mouse of bscEp-CAMxCD3 completely prevented tumor outgrowth when treatment was started at the day of tumor cell inoculation. BscEp-CAMxCD3 was also efficacious when administered up to 8 days after xenograft injection. Established tumors could be eradicated in all animals by five 10 microg doses given between days 8 and 12 after tumor cell inoculation. To test the efficacy of bscEp-CAMxCD3 in a more physiologic model, pieces of primary metastatic tumor tissue from ovarian cancer patients were implanted in NOD/SCID mice. Partial tumor engraftment and growth was observed with four of six patient samples. Treatment of established tumors with daily 5 microg doses led to a significant reduction and, in some cases, eradication of human tumor tissue. These effects obviously relied on the tumor-resident T cells reactivated by bscEp-CAMxCD3. Our data show that the class of single-chain bispecific antibodies has very high antitumor efficacy in vivo and can use previously unstimulated T cells at low effector-to-target ratios.

We examined the chemical composition of extracellular polymeric substances (EPS) extracted from two natural microbial pellicle biofilms growing on acid mine drainage (AMD) solutions. The EPS obtained from a mid-developmental-stage biofilm (DS1) and a mature biofilm (DS2) were qualitatively and quantitatively compared. More than twice as much EPS was derived from DS2 as from DS1 (approximately 340 and 150 mg of EPS per g [dry weight] for DS2 and DS1, respectively). Composition analyses indicated the presence of carbohydrates, metals, proteins, and minor quantities of DNA and lipids, although the relative concentrations of these components were different for the two EPS samples. EPS from DS2 contained higher concentrations of metals and carbohydrates than EPS from DS1. Fe was the most abundant metal in both samples, accounting for about 73% of the total metal content, followed by Al, Mg, and Zn. The relative concentration profile for these metals resembled that for the AMD solution in which the biofilms grew, except for Si, Mn, and Co. Glycosyl composition analysis indicated that both EPS samples were composed primarily of galactose, glucose, heptose, rhamnose, and mannose, while the relative amounts of individual sugars were substantially different in DS1 and DS2. Additionally, carbohydrate linkage analysis revealed multiply linked heptose, galactose, glucose, mannose, and rhamnose, with some of the glucose in a 4-linked form. These results indicate that the biochemical composition of the EPS from these acidic biofilms is dependent on maturity and is controlled by the microbial communities, as well as the local geochemical environment.

Exopolysaccharides (EPS) may have an important role in the Antarctic marine environment, possibly acting as ligands for trace metal nutrients such as iron or providing cryoprotection for growth at low temperature and high salinity. Ten bacterial strains, isolated from Southern Ocean particulate material or from sea ice, were characterized. Whole cell fatty acid profiles and 16S rRNA gene sequences showed that the isolates included representatives of the genera Pseudoalteromonas, Shewanella, Polaribacter, and Flavobacterium as well as one strain, which constituted a new bacterial genus in the family Flavobacteriaceae. The isolates are, therefore, members of the "Gammaproteobacteria" and Cytophaga-Flexibacter-Bacteroides, the taxonomic groups that have been shown to dominate polar sea ice and seawater microbial communities. Exopolysaccharides produced by Antarctic isolates were characterized. Chemical composition and molecular weight data revealed that these EPS were very diverse, even among six closely related Pseudoalteromonas isolates. Most of the EPS contained charged uronic acid residues; several also contained sulfate groups. Some strain produced unusually large polymers (molecular weight up to 5.7 MDa) including one strain in which EPS synthesis is stimulated by low temperature. This study represents a first step in the understanding of the role of bacterial EPS in the Antarctic marine environment.

In this review, we discuss current views of the bone marrow (BM) stem cell (SC) compartment and present data showing that BM contains heterogeneous populations of hematopoietic (H)SCs and non-HSCs. These cells are variously described in the literature as: endothelial progenitor cells (EPCs); mesenchymal (M)SCs; multipotent adult progenitor cells (MAPCs); marrow-isolated adult multilineage inducible (MIAMI) cells; and multipotent adult (MA)SCs. In some cases, it is likely that similar or overlapping populations of primitive SCs in the BM detected using various experimental strategies were assigned different names. Recently, we purified rare CXC chemokine receptor 4 expressing (CXCR4(+)) small SCs from the murine BM that express markers characteristic for embryonic (E)SCs, epiblast (EP)SCs, and primordial germ cells (PGCs). We named these primitive cells very small embryonic-like (VSEL) SCs. Our data indicate that VSELs may differentiate into cells from all three germ layers.

BACKGROUND

Second-generation antipsychotics have been thought to cause fewer extrapyramidal side-effects (EPS) than first-generation antipsychotics, but recent pragmatic trials have indicated equivalence.

OBJECTIVE

To determine whether second-generation antipsychotics had better outcomes in terms of EPS than first-generation drugs.

METHODS

We conducted an intention-to-treat, secondary analysis of data from an earlier randomised controlled trial (n = 227). A clinically significant difference was defined as double or half the symptoms in groups prescribed first- v. second-generation antipsychotics, represented by odds ratios greater than 2.0 (indicating advantage for first-generation drugs) or less than 0.5 (indicating advantage for the newer drugs). We also examined EPS in terms of symptoms emergent at 12 weeks and 52 weeks, and symptoms that had resolved at these time points.

RESULTS

At baseline those randomised to the first-generation antipsychotic group (n = 118) had similar EPS to the second-generation group (n = 109). Indications of resolved Parkinsonism (OR = 0.5) and akathisia (OR = 0.4) and increased tardive dyskinesia (OR = 2.2) in the second-generation drug group at 12 weeks were not statistically significant and the effects were not present by 52 weeks. Patients in the second-generation group were dramatically (30-fold) less likely to be prescribed adjunctive anticholinergic medication, despite equivalence in terms of EPS.

CONCLUSIONS

The expected improvement in EPS profiles for participants randomised to second-generation drugs was not found; the prognosis over 1 year of those in the first-generation arm was no worse in these terms. The place of careful prescription of first-generation drugs in contemporary practice remains to be defined, potentially improving clinical effectiveness and avoiding life-shortening metabolic disturbances in some patients currently treated with the narrow range of second-generation antipsychotics used in routine practice. This has educational implications because a generation of psychiatrists now has little or no experience with first-generation antipsychotic prescription.

OBJECTIVE

Supine anteroposterior (AP) chest radiographs in patients with blunt trauma have poor sensitivity for the identification of pneumothorax. Ultrasound (US) has been proposed as an alternative screening test for pneumothorax in this population. The authors conducted an evidence-based review of the medical literature to compare sensitivity of bedside US and AP chest radiographs in identifying pneumothorax after blunt trauma.

METHODS

MEDLINE and EMBASE databases were searched for trials from 1965 through June 2009 using a search strategy derived from the following PICO formulation of our clinical question: patients included adult (18 + years) emergency department (ED) patients in whom pneumothorax was suspected after blunt trauma. The intervention was thoracic ultrasonography for the detection of pneumothorax. The comparator was the supine AP chest radiograph during the initial evaluation of the patient. The outcome was the diagnostic performance of US in identifying the presence of pneumothorax in the study population. The criterion standard for the presence or absence of pneumothorax was computed tomography (CT) of the chest or a rush of air during thoracostomy tube placement (in unstable patients). Prospective, observational trials of emergency physician (EP)-performed thoracic US were included. Trials in which the exams were performed by radiologists or surgeons, or trials that investigated patients suffering penetrating trauma or with spontaneous or iatrogenic pneumothoraces, were excluded. The methodologic quality of the studies was assessed. Qualitative methods were used to summarize the study results. Data analysis consisted of test performance (sensitivity and specificity, with 95% confidence intervals [CIs]) of thoracic US and supine AP chest radiography.

RESULTS

Four prospective observational studies were identified, with a total of 606 subjects who met the inclusion and exclusion criteria. The sensitivity and specificity of US for the detection of pneumothorax ranged from 86% to 98% and 97% to 100%, respectively. The sensitivity of supine AP chest radiographs for the detection of pneumothorax ranged from 28% to 75%. The specificity of supine AP chest radiographs was 100% in all included studies.

CONCLUSIONS

This evidence-based review suggests that bedside thoracic US is a more sensitive screening test than supine AP chest radiography for the detection of pneumothorax in adult patients with blunt chest trauma.

BACKGROUND

Extrapyramidal signs (EPS) are common in Alzheimer disease (AD) and increase in prevalence as AD advances. The neuropathologic substrate responsible for EPS in AD remains to be fully characterized.

METHODS

Subjects had a clinical diagnosis of AD confirmed by neuropathologic examination. EPS during life were documented by clinical methods assessing bradykinesia, cogwheel rigidity, rest tremor, and parkinsonian gait. Subjects with EPS and previous neuroleptic exposure were excluded. Twenty-eight subjects were in the EPS group and 104 subjects were without EPS. Neuron loss, alpha-synuclein (ASYN)-labeled pathology, and tau-labeled pathology in the substantia nigra were measured using semiquantitative techniques such that higher scores represented increased pathologic burden.

RESULTS

Presence of nigral ASYN-labeled pathology was more common (50 vs 28.9%; p < 0.05) in the EPS group than in those without EPS. There was more nigral neuron loss in the EPS group (1.50 vs 1.11 in no-EPS group; p < 0.05). Tau-labeled burden was not different by group comparisons; however, EPS onset at later stages of dementia severity was associated with increased tau-labeled pathology (Kendall tau-B = 0.48, p < 0.01) and this association remained after controlling for dementia severity at death. Additionally, moderate to severe tau burden was more common in the subgroup with "pure AD" (definite AD without other neuropathology) with EPS (81.8%) than cases without EPS (49.0%; p < 0.05). Four subjects with EPS (14.3%) had little to no significant nigral pathologic changes.

CONCLUSIONS

Clinically detected extrapyramidal signs (EPS) in Alzheimer disease (AD) are associated with substantia nigra pathology including alpha-synuclein aggregation, hyperphosphorylated tau accumulation, and neuron loss that may account for the increasing prevalence of EPS as AD progresses. In some cases, limited nigral pathology suggests extranigral factors in the clinical symptoms of EPS.

PGE(2) is a potent stimulator of renin release. So far, the contribution of each of the four PGE(2) receptor subtypes (EP(1)-EP(4)) in the regulation of renin release has not been characterized. Therefore, we investigated the effects PGE(2) on renin secretion rates (RSR) from isolated, perfused kidneys of EP(1)-/-, EP(2)-/-, EP(3)-/-, EP(4)-/-, and wild-type mice. PGE(2) concentration dependently stimulated RSR from kidneys of all four knockout strains with a threshold concentration of 1 nM in EP(1)-/-, EP(2)-/-, EP(3)-/-, and wild-type mice, whereas the threshold concentration was shifted to 10 nM in EP(4)-/- mice. Moreover, the maximum stimulation of RSR by PGE(2) at 1 microM was significantly reduced in EP(4)-/- (12.8-fold of control) and EP(2)-/- (15.9-fold) compared with wild-type (20.7-fold), EP(1)-/- (23.8-fold), and EP(3)-/- (20.1-fold). In contrast, stimulation of RSR by either the loop diuretic bumetanide or the beta-adrenoceptor agonist isoproterenol was similar in all strains. PGE(2) exerted a dual effect on renal vascular tone, inducing vasodilatation at low concentrations (1 nmol/) and vasoconstriction at higher concentrations (100 nmol/) in kidneys of wild-type mice. In kidneys of EP(2)-/- as well as EP(4)-/- mice, vasodilatation at low PGE(2) concentrations was prevented, whereas vasoconstriction at higher concentrations was augmented. In contrast, the vasodilatory component was pronounced in kidneys of EP(1) and EP(3) knockout mice, whereas in both genotypes the vasoconstriction at higher PGE(2) concentrations was markedly blunted. Our data provide evidence that PGE(2) stimulates renin release via activation of EP(2) and EP(4) receptors, whereas EP(1) and EP(3) receptors appear to be without functional relevance in juxtaglomerular cells. In contrast, all four receptor subtypes are involved in the control of renal vascular tone, EP(1) and EP(3) receptors increasing, and EP(2) as well as EP(4) receptors, decreasing it.

To compare the analgesic efficacy and plasma concentration of intramuscular (IM) versus epidural (EP) clonidine, 20 patients recovering from orthopedic or perineal surgery were randomly divided into two groups of ten. Clonidine (2 micrograms/kg) was administered epidurally in group 1 and intramuscularly in group 2. Analgesia was assessed using a visual analog scale (VAS) over a period of 6 h following clonidine administration. Venous blood samples were obtained at specific intervals for radioimmunoassay determination of plasma clonidine concentrations. The maximum reduction in VAS pain score was 78.5 +/- 20.6% in the EP group and 68.1 +/- 31.5% in the IM group (NS). Onset of analgesia was similar (within 15 min of injection), but duration tended to be longer after epidural than intramuscular administration (208 +/- 87 min vs. 168 +/- 95 min, mean +/- SD, P greater than 0.05). The peak plasma clonidine concentration after EP injection was 0.82 +/- 0.22 ng/ml and 1.02 +/- 0.76 ng/ml after IM injection. Hypotension, bradycardia, and drowsiness occurred with both methods of administration. None of these effects required treatment. Thus, in postoperative patients clonidine produces similar analgesia and side effects after parenteral or EP administration.

BACKGROUND

Recently, the "Remission in Schizophrenia Working Group" proposed remission criteria consisting of a reduction to mild levels on key symptoms for at least 6 months.

OBJECTIVE

This study applied these remission criteria to a large first-episode psychosis sample in order to (1) determine the rates of remission; (2) explore predictors of remission; and (3) test the external validity of these criteria.

METHODS

We analyzed data from 462 subjects with a first-episode of psychosis who participated in a long-term, multinational, randomized, double-blinded trial of risperidone and haloperidol over 2 to 4 years.

RESULTS

At some time point in the study 323 (70%) of the 462 subjects had a reduction to mild levels on the key symptoms as measured by the PANSS although only 109 (23.6%) maintained this level for at least 6 months thereby meeting remission criteria. The two strongest predictors of remission were shorter duration of untreated psychosis (p=0.01) and treatment response at 6 weeks (p=0.001). Compared to non-remitted patients, those in remission experienced greater improvement on all PANSS subscales (p<.0001), CGI-S (p<.0001), better quality of life (p=0.006), fewer relapses (p<.0001), displayed a more favorable attitude towards their medication (p=.002), had lower EPS levels according to the ESRS (p=<.0001) and received lower doses of antipsychotic medication (p=0.003). The remission and non-remission groups did not differ significantly regarding composite cognitive scores, suicidality and body mass index.

CONCLUSIONS

The results suggest that the remission criteria, although based solely on core symptom improvement, can effectively identify patients who have a more favorable overall outcome.

Destruction of Kupffer cells with gadolinium chloride (GdCl(3)) and intestinal sterilization with antibiotics diminished ethanol-induced steatosis in the enteral ethanol feeding model. However, mechanisms of ethanol-induced fatty liver remain unclear. Accordingly, the role of Kupffer cells in ethanol-induced fat accumulation was studied. Rats were given ethanol (5 g/kg body wt) intragastrically, and tissue triglycerides were measured enzymatically. Kupffer cells were isolated 0-24 h after ethanol, and PGE(2) production was measured by ELISA, whereas inducible cyclooxygenase (COX-2) mRNA was detected by RT-PCR. As expected, ethanol increased liver triglycerides about threefold. This increase was blunted by antibiotics, GdCl(3), the dihydropyridine-type Ca(2+) channel blocker nimodipine, and the COX inhibitor indomethacin. Ethanol also increased PGE(2) production by Kupffer cells about threefold. This increase was also blunted significantly by antibiotics, nimodipine, and indomethacin. Furthermore, tissue triglycerides were increased about threefold by PGE(2) treatment in vivo as well as by a PGE(2) EP(2)/EP(4) receptor agonist, whereas an EP(1)/EP(3) agonist had no effect. Moreover, permeable cAMP analogs also increased triglyceride content in the liver significantly. We conclude that PGE(2) derived from Kupffer cells, which are activated by ethanol, interacts with prostanoid receptors on hepatocytes to increase cAMP, which causes triglyceride accumulation in the liver. This mechanism is one of many involved in fatty liver caused by ethanol.

OBJECTIVE

To investigate long-term changes in the anterior segment of primate eyes treated for one year with different prostaglandin agonists and a prostamide. The results were compared with those obtained after vehicle treatment and in untreated controls.

METHODS

Sixteen young cynomolgus monkeys were unilaterally topically treated for 1 year with either bimatoprost 0.03% (prostamide), sulprostone 0.03% (EP(3)/EP(1) agonist), AH13205 0.1% (EP(2) agonist), or latanoprost 0.005% (FP agonist), which all lower IOP in this species at the doses applied. Four animals were treated with the vehicle only. In all cases the left eye was treated, the right eye remained untreated. Six monkeys served as untreated controls. Sections from 4 quadrants each of the circumference of the eyes of 16 drug-treated, 4 vehicle-treated and 6 untreated control animals were investigated qualitatively and quantitatively using light- and electronmicroscopy. The area of widened spaces between ciliary muscle bundles, the number of nerve fiber bundles at the muscle tips, and the width and length of the ciliary muscle were quantitated.

RESULTS

The general morphology of the ciliary muscle and trabecular meshwork was normal in appearance and shape in all animals, whereas some localized morphologic changes were observed in the drug-treated animals. The changes were found to be similar in all four treatment groups. In the ciliary muscle, there was a significant increase in optically empty spaces between muscle bundles in the anterior portion of the longitudinal and the reticular ciliary muscle compared with untreated and vehicle-treated control animals. Within these spaces, significantly more myelinated nerve fiber bundles were found in drug-treated compared with normal control animals. Ultrastructurally the spaces were partly covered by endothelial-like cells which, in some areas, were in contact with the basement membrane of the microvasculature. In all treatment groups, there were also changes in the trabecular meshwork region. Significant regional differences among the different quadrants of the eyes and quantitative differences between treatment groups were observed. The ciliary epithelium had a normal appearance in all treatment groups.

CONCLUSIONS

After one year of treatment with different prostaglandins and a prostamide, uveoscleral outflow pathways are enlarged and appear organized. Conventional outflow routes were also affected. Long-term treatment with AH13205, latanoprost, sulprostone, or bimatoprost also induces sprouting of nerve fibers.

The composition of extracellular polymeric substances (EPS) from Shewanella sp. HRCR-1 biofilms was investigated using infrared spectroscopy and proteomics to provide insight into potential ecophysiological functions and redox activity of the EPS. Both bound and loosely associated EPS were extracted from Shewanella sp. HRCR-1 biofilms prepared using a hollow-fibre membrane biofilm reactor. Fourier transform infrared spectra revealed the presence of proteins, polysaccharides, nucleic acids, membrane lipids and fatty acids in the EPS fractions. Using a global proteomic approach, a total of 58 extracellular and outer membrane proteins were identified in the EPS. These included homologues of multiple Shewanella oneidensis MR-1 proteins that potentially contribute to key physiological biofilm processes, such as biofilm-promoting protein BpfA, surface-associated serine protease, nucleotidases (CpdB and UshA), an extracellular lipase, and oligopeptidases (PtrB and a M13 family oligopeptidase lipoprotein). In addition, 20 redox proteins were found in extracted EPS. Among the detected redox proteins were the homologues of two S. oneidensis MR-1 c-type cytochromes, MtrC and OmcA, which have been implicated in extracellular electron transfer. Given their detection in the EPS of Shewanella sp. HRCR-1 biofilms, c-type cytochromes may contribute to the possible redox activity of the biofilm matrix and play important roles in extracellular electron transfer reactions.

Prostaglandins (PGs) are potent autocrine and paracrine oxygenated lipid molecules that contribute appreciably to physiologic and pathophysiologic responses in almost all organs, including brain. Emerging data indicate that the PGs, and more specifically PGE2, play a central role in brain diseases including ischemic injury and several neurodegenerative diseases. Given concerns over the potential toxicity from protracted use of cyclooxygenase inhibitors in the elderly, attention is now focused on blocking PGE2 signaling that is mediated by interactions with four distinct G protein-coupled receptors, EPEPEPEP receptor subtypes in Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, and ischemic stroke. However promising these preclinical studies are, they have yet to be followed by clinical trials targeting any EP receptor in neurologic diseases.

BACKGROUND

Understanding individual differences in the development of extrapyramidal side effects (EPS) as a response to antipsychotic therapy is essential to individualize treatment.

METHODS

We performed genomewide association studies to search for genetic susceptibility to EPS. Our sample consisted of 738 schizophrenia patients, genotyped for 492K single nucleotide polymorphisms (SNPs). We studied three quantitative measures of antipsychotic adverse drug reactions-the Simpson-Angus Scale (SAS) for Parkinsonism, the Barnes Akathisia Rating Scale, and the Abnormal Involuntary Movement Scale (AIMS)-as well as a clinical diagnosis of probable tardive dyskinesia.

RESULTS

Two SNPs for SAS, rs17022444 and rs2126709 with p = 1.2 x 10(-10) and p = 3.8 x 10(-7), respectively, and one for AIMS, rs7669317 with p = 7.7 x 10(-8), reached genomewide significance (Q value < .1). rs17022444 and rs7669317 were located in intergenic regions and rs2126709 was located in ZNF202 on 11q24. Fourteen additional signals were potentially interesting (Q value < .5). The ZNF202 is a transcriptional repressor controlling, among other genes, PLP1, which is the major protein in myelin. Mutations in PLP1 cause Pelizaeus-Merzbacher disease, which has Parkinsonism as an occurring symptom. Altered mRNA expression of PLP1 is associated with schizophrenia.

CONCLUSIONS

Although our findings require replication and validation, this study demonstrates the potential of genomewide association studies to discover genes and pathways that mediate adverse effects of antipsychotics.

Between the acquisition of Evoked Potential (EP) data and their interpretation lies a major problem: What to measure? An approach to this kind of problem is outlined here in terms of Principal Components Analysis (PCA). An important second theme is that experimental manipulation is important to functional interpretation. It would be desirable to have a system of EP measurement with the following characteristics: (1) represent the data in a concise, parsimonous way; (2) determine EP components from the data without assuming in advance any particular waveforms for the components; (3) extract components which are independent of each other; (4) measure the amounts (contributions) of various components in observed EPs; (5) use measures that have greater reliability than measures at any single time point or peak; and (6) identify and measure components that overlap in time. PCA has these desirable characteristics. Simulations are illustrated. PCA's beauty also has some warts that are discussed. In addition to discussing the usual two-mode model of PCA, an extension of PCA to a three-mode model is described that provides separate parameters for (1) waveforms over time, (2) coefficients for spatial distribution, and (3) scores telling the amount of each component in each EP. PCA is compared with more traditional approaches. Some biophysical considerations are briefly discussed. Choices to be made in applying PCA are considered. Other issues include misallocation of variance, overlapping components, validation, and latency changes.

Centromere positioning in human cell nuclei was traced in non-cycling peripheral blood lymphocytes (G0) and in terminally differentiated monocytes, as well as in cycling phytohemagglutinin-stimulated lymphocytes, diploid lymphoblastoid cells, normal fibroblasts, and neuroblastoma SH-EP cells using immunostaining of kinetochores, confocal microscopy and three-dimensional image analysis. Cell cycle stages were identified for each individual cell by a combination of replication labeling with 5-bromo-2'-deoxyuridine and immunostaining of pKi67. We demonstrate that the behavior of centromeres is similar in all cell types studied: a large fraction of centromeres are in the nuclear interior during early G1; in late G1 and early S phase, centromeres shift to the nuclear periphery and fuse in clusters. Peripheral location and clustering of centromeres are most pronounced in non-cycling cells (G0) and terminally differentiated monocytes. In late S and G2, centromeres partially decluster and migrate towards the nuclear interior. In the rather flat nuclei of adherently growing fibroblasts and neuroblastoma cells, kinetochores showed asymmetrical distributions with preferential kinetochore location close either to the bottom side of the nucleus (adjacent to the growth surface) or to the nuclear upper side. This asymmetrical distribution of centromeres is considered to be a consequence of chromosome arrangement in anaphase rosettes.

The role of bacteriophages as natural vectors for some of the most potent bacterial toxins is well recognized and includes classical type I membrane-acting superantigens, type II pore-forming lysins, and type III exotoxins, such as diphtheria and botulinum toxins. Among Gram-negative pathogens, a novel class of bacterial virulence factors called effector proteins (EPs) are phage encoded among pathovars of Escherichia coli, Shigella spp., and Salmonella enterica. This chapter gives an overview of the different types of virulence factors encoded within phage genomes based on their role in bacterial pathogenesis. It also discusses phage-pathogenicity island interactions uncovered from studies of phage-encoded EPs. A detailed examination of the filamentous phage CTXφ that encodes cholera toxin is given as the sole example to date of a single-stranded DNA phage that encodes a bacterial toxin.

OBJECTIVE

To record and characterize intracochlear evoked potentials (EPs) for a variety of electrical stimuli in studies with cochlear implant patients.

METHODS

Recordings were made with patients having direct percutaneous access to their implanted electrodes. Intracochlear voltages were recorded via unstimulated electrodes. The stimuli included trains of identical pulses, with pulse rates ranging from 100 to 4065/s, and a modulated pulse train produced by a single-channel speech processor, with the pulse rate of 824/s.

RESULTS

Magnitudes of EPs for each pulse in trains of identical pulses were uniform for pulse rates below about 200/s. For rates between about 400 and 1000/s, an alternating pattern of EP magnitudes was observed, with relatively large EPs following the odd-numbered pulses. For rates between about 1000 and 3000/s, more complex patterns were observed. After the first millisecond of each train at even higher rates, uniform EPs again were observed across pulses, although the absolute magnitude of the EPs was much lower than that observed for low rates of stimulation. The approximate rates corresponding to boundaries between these different regions varied among subjects and among electrodes within subjects. EP magnitudes for the modulated pulse train reflected the gross periodicity of the modulation waveform but did not reflect temporal details within the periods.

CONCLUSIONS

Population responses of the human auditory nerve, as indicated by EP magnitudes, reflect the amplitudes of electrical pulses for pulse rates below about 200/s and above about 3000/s. Use of intermediate rates may introduce distortions in the transmission of stimulus information with cochlear implants.

The nucleus accumbens (NAcc) likely plays a role in the rewarding effects of several addictive drugs such as opiates and EtOH. We showed previously that low EtOH concentrations reduced glutamatergic excitatory postsynaptic potentials (EP-SPs) in NAcc neurons. Naloxone inhibited this effect. In the present study we have begun characterizing the receptors involved in the evoked EPSPs and examined the action of EtOH on these receptors by using intracellular recording (voltage- and current-clamp) in the rat NAcc slice. At depolarized membrane potentials, we found 6-cyano-7-nitroquinoxaline-2,3-di-one-resistant EPSPs that were blocked by the N-methyl-D-aspartate (NMDA) receptor antagonist DL-2-amino-5-phosphonovalerate. In 6-cyano-7-nitroquinoxaline-2,3-dione (a non-NMDA glutamate receptor antagonist), EtOH 66 mM decreased these NMDA-EPSPs. Application of exogenous NMDA or non-NMDA [kainate, (R,S)-alpha-amino-3-hydroxy-5-methyli-soxazole-4-propionic acid or quisqualate] glutamate agonists evoked reversible depolarizations or inward currents. The NMDA-induced currents increased with membrane depolarization and were blocked by DL-2-amino-5-phosphonovalerate. EtOH 11 to 200 mM decreased the NMDA currents significantly and dose-dependently, without effect of naloxone. Higher EtOH concentrations (44-66 mM) also reduced slightly kainate-induced currents (again without a naloxone effect), but not (R,S)-alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid or quisqualate currents. These data suggest that NAcc core neurons express both NMDA and non-NMDA glutamate receptors. Because low EtOH concentrations reduce the EPSPs at normal resting potentials, but not responses to non-NMDA glutamate agonists, EtOH probably acts both pre- and postsynaptically: by an opioid-dependent reduction of glutamate release and by postsynaptically reducing NMDA and kainate currents. By virtue of the likely role NAcc plays in alcoholism, these actions could represent major determinants in the intoxicating and reinforcing properties of EtOH.