Objective: The ann of this study was to determine whether hyperbilirubinemia affects the association between a Positive urine nitrite test and a positive urine culture. Methods: We conducted an institutional review board-approved, retrospective review of 12 months of patient data, compiling information for patients having urinalysis, urine culture, and total serum bilirubin. Patients were divided into 3 groups according to total serum bilirubin: less than 1.5 mg/dL, 1.5 to 3.0 mg/dL, and greater than 3.0 mg/dL. The point estimates and 95% confidence intervals of the sensitivity, specificity, false-positive proportion (proportion of false positive to all positive tests), and other test characteristics ofurine nitrite as an indicator of urinary tract infection were calculated and tested for trend as a function of the 3 total serum bilirubin ranges. Results: Three thousand one hundred seventy-four patients met our study criteria. Specificity of the nitrite test decreased as a function of increasing total serum bilirubin (0.974, 0.966, and 0.855 for the 3 total bilirubin levels, respectively) with a significant trend (P < .0001). There was no significant trend in comparable sensitivity values (0.380, 0.417, and 0.241, respectively) with P = .55. The false-positive proportion also increased as a function of total serum bilirubin (17.5%, 17.3%, and 72.0%) with P < .0001. Thus, if a patient's total serum bilirubin was elevated to the point of jaundice (> 3.0 mg/dL), it was approximately 4 times more likely that a positive urine nitrite test would be a "false positive" (ie, nitrite-positive/culture-negative) compared with those with normal serum bilirubin levels. Conclusions: Specificity of the urine nitrite test for urinary tract infection decreases as a function of increasing serum bilirubin. Most patients with hyperbilirubinemia and a positive nitrite test in our sample did not have an associated urinary tract infection. (c) 2007 Elsevier Inc. All rights reserved.
Brainstem cholinergic populations survive in neurodegenerative disease, while basal forebrain cholinergic neurons degenerate. We have postulated that variable resistance to oxidative stress may in part explain this. Rat primary cultures were used to study the effects of several nitrosative/oxidative stressors on brainstem (upper pons, containing pedunculopontine and lateraldorsal tegmental nuclei; BS) cholinergic neurons, comparing them with medial septal (MS), and striatal cholinergic neurons. BS cholinergic neurons were significantly more resistant to S-nitro-N-acetyl-d,l-penicillamine (SNAP), sodium nitroprusside (SNP), and hydrogen peroxide than were MS cholinergic neurons, which in turn were more resistant than striatal cholinergic neurons. Pharmacological analyses using specific inhibitors of neuroprotective systems also revealed differences between these three cholinergic populations with respect to their vulnerability to SNAP. Toxicity of SNAP to BS neurons was exacerbated by blocking NF-kappaB activation with SN50 or ERK1/2 activation by PD98059, or by inhibition of phosphoinositide-3 kinase (PI3K) activity by LY294002. In contrast, SNAP toxicity to MS neurons was augmented only by SN50, and SNAP toxicity to striatal cholinergic neurons was not increased by any of these three pharmacological agents. In neuron-enriched primary cultures, BS cholinergic neurons remained resistant to SNAP while MS cholinergic neurons remained vulnerable to this agent. Immunohistochemical experiments demonstrated nitric oxide (NO)-induced increases in nuclear levels of phospho-epitopes for ERK1/2 and Akt, and of the p65 subunit of NF-kappaB, within BS cholinergic neurons. These data indicate that the relative resistance of BS cholinergic neurons to toxic levels of nitric oxide involves three intrinsic neuroprotective pathways that control transcriptional and anti-apoptotic cellular functions.
Neurons and glia within the hippocampus of aged, spatial learning-impaired Long-Evans rats exhibit uniquely altered gene expression profiles, and we have postulated oxidative stress as the basis for this. To test this hypothesis we quantitated the extent of protein and nucleic acid oxidative damage, evaluated the status of mitochondrial DNA integrity, and examined several signaling entities and molecular indicators frequently associated with oxidative stress and gliosis. Immunoblotting demonstrated elevated heme oxygenase-1 in the aged-impaired hippocampus and immunocytochemistry suggested that heme oxygenase-1 is largely cytosolic and at least partly neuronal in nature. In the aged-impaired group, immunoreactivity to 8-hydroxy-2'-deoxyguanosine, an oxidative nucleic acid adduct, was found to be elevated in the dentate gyrus and in area CA1 of the hippocampal formation. Isolated mitochondrial DNA was found to be significantly damaged in the aged-impaired group. In the aged learning-impaired rats only, proteins in a 65-kDa band were found to contain excessive levels of carbonyl residues. Glial activation was examined by in situ hybridization histochemistry to tumor necrosis factor alpha and by immunocytochemistry with OX-6, which detects activated microglia. White matter in aged brains exhibited a modest up-regulation of tumor necrosis factor alpha mRNA and OX-6 immunoreactivity, but the hippocampal formation expressed tumor necrosis factor alpha mRNA equivalent to young animals and few OX-6-positive microglia. The mRNA for manganese-dependent superoxide dismutase, which is elevated in the aged hippocampus, was found preferentially expressed in neurons. We conclude that aged hippocampal neurons appear to be under oxidative stress and this is more severe in the learning-impaired subjects, suggesting a possible basis for age-induced cognitive decline.
Few muscarinic antagonists differentiate between the M4 and M2 muscarinic receptors. In a structure activity study, aimed at discovering leads for the development of a M4 muscarinic receptor-selective antagonist, we have synthesized and tested at cloned muscarinic receptors the binding of a group of dioxolane- or oxadiazole-dialkyl amines, and compared them to our compound 1, which contains the furan nucleus. Although none of these agents were particularly potent at M4 receptors (Kd values were typically 30-70 nM), furan derivatives (-)1 and (+)1 were significantly more potent at M4 receptors than at M2 receptors (approximately 3- and 4-fold, respectively). The dioxolane derivatives 12b and 12c were more than 10-fold selective for the M4 versus the M2 receptors, while the dioxolane derivative 12e was 15-fold more potent at M4 receptors than for M2 receptors. However, these agents bound to M3 receptors with potencies like that for the M4 receptor, so they are not M4-selective. The M4/M2 relative selectivities of some of our compounds are similar to the better hexahydrosiladifenidol derivatives, and may provide some important structural clues for the development of potent and selective M4 antagonists.
Many neuronal nitric oxide synthase (nNOS)-expressing brain neurons, including some cholinergic populations, are resistant to disease or to certain forms of excitotoxicity. Vulnerability to NO excess of forebrain (medial septal/diagonal band; MSACh) and brainstem (pedunculopontine/laterodorsal tegmental nuclei; BS-ACh) cholinergic neurons was compared in E16-E18 primary rat brain cultures. MS-ACh cells were ∼300-fold more sensitive to the NO donor S-nitro-N-acetyl-D,L-penicillamine (SNAP) than were BS-ACh cells. Most (69%) MS-ACh cells contained nuclear DNA fragments by 2 h after addition of SNAP, while only 21% BS-ACh cells were TUNEL-positive after NO excess. Depletion of glutathione content did not potentiate the effect of SNAP on MS-ACh cells, but sensitized BS-ACh cells to the NO donor. Caffeic acid, a putative NF-KB inhibitor, enhanced the toxicity of SNAP to cholinergic neurons in both preparations. Our experiments show that cholinergic neurons in mixed primary cultures from different brain regions possess biochemical differences with respect to their vulnerability to NO excess.
Messenger RNA (mRNA) molecules encoding proteins related to the presynaptic cholinergic and neurotrophin systems were quantitated in the hippocampus and basal forebrain of Long–Evans rats with spatial learning ability assessed in the Morris water maze. The reverse transcriptase-polymerase chain reaction showed that the mRNAs for the low-affinity neurotrophin receptor (p75-NTR) and the growth-associated protein GAP-43 were decreased in level in the basal forebrain of aged-impaired rats. In the hippocampus of these aged-impaired rats, the mRNA for VGF, another neurotrophin-inducible gene, also was decreased. In situ hybridization histochemistry revealed that mRNAs for nerve growth factor (NGF) and brain-derived neurotrophic factor increased in level in the aged rat hippocampus; when age effects were removed, NGF mRNA level remained significantly correlated with maze performance. Enzyme-linked immunosorbent assay indicated that NGF protein was expressed at normal levels in the aged rat hippocampus. These mRNA and protein alterations may signify that a defect in neurotrophin signaling exists in the brains of aged Long–Evans rats, underlying reduced plasticity responses in the basal forebrain cholinergic system.
Jesus and the Victory of God, N. T. Wright
A number of pharmacological, anatomical, and immunological studies have previously addressed the subtype identity of the hippocampal muscarinic pre-synaptic autoreceptor. A preponderance of findings indicate that it is of the M2 pharmacological type. Both the m2 and m4 molecular subtypes exhibit M2 pharmacology and there are few drugs that differentiate between these receptors. Pharmacological attempts at defining the hippocampal autoreceptor have yielded conflicting results. The basal forebrain is relatively enriched in m2 muscarinic receptor mRNA and protein, and lesions that denervate the hippocampus of its basal forebrain cholinergic input have shown a decrement in m2, but not m4, receptor protein in the hippocampus. Thus, the anatomical data obtained to date tend to support the view that the m2 subtype is expressed as the hippocampal autoreceptor. We have combined in situ hybridization histochemistry (ISHH) with immunocytochemistry to choline acetyltransferase to examine whether mRNA for the m4 subtype of muscarinic receptor is expressed in central cholinergic neurons. The m4 muscarinic mRNA was found at moderate levels in all subdivisions of the cholinergic basal forebrain, including the medial septum/diagonal band complex (MS/DB). The m4 mRNA was also found in striatal cholinergic interneurons, in the cholinergic reticular core of the upper brainstem, and in brainstem cholinergic motor neurons. Muscarinic m4 receptor mRNA was also found in many non-cholinergic cells in the brain. For example, the hippocampal pyramidal neurons, dentate gyrus granule cells, and entorhinal cortical pyramidal neurons express relatively high levels of m4 mRNA, while in the brainstem the dorsal raphe and pontine reticular nuclei express relatively high levels of this mRNA. The finding of m4 mRNA in the MS/DB cholinergic neurons suggests that this receptor protein might be expressed as an autoreceptor in hippocampal cholinergic terminals.
The Experimental Physics and Industrial Control System (EPICS) uses a broadcast method to locate resources and controls distributed across control servers. There are many advantages offered by using a centrally managed name resolution method, in which resources are located using a repository. The suitability of DCE Directory Service as a name resolution method is explored, and results from a study involving DCE are discussed. An alternative nameserver method developed and in use at the Thomas Jefferson National Accelerator Facility (Jefferson Lab) is described and results of integrating this new method with existing EPICS utilities presented. The various methods discussed in the paper are compared.