NAAG peptidase inhibition reduces locomotor activity and some stereotypes in the PCP model of schizophrenia via group II mGluR

Phencyclidine (PCP) administration elicits positive and negative symptoms that resemble those of schizophrenia and is widely accepted as a model for the study of this human disorder. Group II metabotropic glutamate receptor (mGluR) agonists have been reported to reduce the behavioral and neurochemical effects of PCP. The peptide neurotransmitter, N-acetylaspartylglutamate (NAAG), is a selective group II agonist. We synthesized and characterized a urea-based NAAG analogue, ZJ43. This novel compound is a potent inhibitor of enzymes, glutamate carboxypeptidase II (K(i) = 0.8 nM) and III (K(i) = 23 nM) that deactivate NAAG following synaptic release. ZJ43 (100 microM) does not directly interact with NMDA receptors or metabotropic glutamate receptors. Administration of ZJ43 significantly reduced PCP-induced motor activation, falling while walking, stereotypic circling behavior, and head movements. To test the hypothesis that this effect of ZJ43 was mediated by increasing the activation of mGluR3 via increased levels of extracellular NAAG, the group II mGluR selective antagonist LY341495 was co-administered with ZJ43 prior to PCP treatment. This antagonist completely reversed the effects of ZJ43. Additionally, LY341495 alone increased PCP-induced motor activity and head movements suggesting that normal levels of NAAG act to moderate the effect of PCP on motor activation via a group II mGluR. These data support the view that NAAG peptidase inhibitors may represent a new therapeutic approach to some of the components of schizophrenia that are modeled by PCP.     

Legionella Contamination in Hot Water of Italian Hotels

A cross-sectional multicenter survey of Italian hotels was conducted to investigate Legionella spp. contamination of hot water. Chemical parameters (hardness, free chlorine concentration, and trace element concentrations), water systems, and building characteristics were evaluated to study risk factors for colonization. The hot water systems of Italian hotels were strongly colonized by Legionella; 75% of the buildings examined and 60% of the water samples were contaminated, mainly at levels of ≥10³ CFU liter⁻¹, and Legionella pneumophila was the most frequently isolated species (87%). L. pneumophila serogroup 1 was isolated from 45.8% of the contaminated sites and from 32.5% of the hotels examined. When a multivariate logistic model was used, only hotel age was associated with contamination, but the risk factors differed depending on the contaminating species and serogroup. Soft water with higher chlorine levels and higher temperatures were associated with L.pneumophila serogroup 1 colonization, whereas the opposite was observed for serogroups 2 to 14. In conclusion, Italian hotels, particularly those located in old buildings, represent a major source of risk for Legionnaires' disease due to the high frequency of Legionella contamination, high germ concentration, and major L. pneumophila serogroup 1 colonization. The possible role of chlorine in favoring the survival of Legionella species is discussed.     

Factorial analysis of the influence of dissolution medium on drug release from carrageenan-diltiazem complexes

This research studied the influence of buffer composition, pH, and ionic strength on the release of diltiazem hydrochloride from a complex of the drug with lambda carrageenan. Two viscosity grades of carrageenan were also compared. A factorial analysis was used to evaluate the influence of individual variables and their interactions. Both the complex solubility, measured as the drug concentration in equilibrium with the solid complex, and the drug release rate from constant surface area were considered. The increase of ionic strength significantly increased complex solubility in all the buffer systems. A significant effect of polymer grade on complex solubility was evidenced only in phosphate buffer with a pH of 6.8, indicating lower solubility of the complex when higher polymer molecular weight was involved. In most cases, drug release rate decreased when high polymer grade was involved in the complex. Ionic strength did not always have a significant effect on drug release rate and was quantitatively less important than for solubility lonic strength especially affected the drug release profiles. At higher ionic strength drug release was no longer constant, but decreased with time, probably because of lower polymer solubility.     

The organization of somatosensory cortex in the short-tailed opossum (Monodelphis domestica)

The organization of neocortex in the short-tailed opossum (Monodelphis domestica) was explored with multiunit microelectrode recordings from middle layers of cortex. Microelectrode maps were subsequently related to the chemoarchitecture of flattened cortical preparations, sectioned parallel to the cortical surface and processed for either cytochrome oxidase (CO) or NADPH-diaphorase (NADPHd) histochemistry. The recordings revealed the presence of at least two systematic representations of the contralateral body surface located in a continuous strip of cortex running from the rhinal sulcus to the medial wall. The primary somatosensory area (S1) was located medially while secondary somatosensory cortex (S2) formed a laterally located mirror image of S1. Auditory cortex was located in lateral cortex at the caudal border of S2, and some electrode penetrations in this area responded to both auditory and somatosensory stimulation. Auditory cortex was outlined by a dark oval visible in flattened brain sections. A large primary visual cortex (V1) was located at the caudal pole of cortex, and also consistently corresponded to a large chemoarchitecturally visible oval. Cortex just rostral and lateral to V1 responded to visual stimulation, while bimodal auditory/visual responses were obtained in an area between V1 and somatosensory cortex. The results are compared with brain organization in other marsupials and with placentals and the evolution of cortical areas in mammals is discussed.     

Comparison of the mycobacteria growth indicator tube with radiometric and solid culture for isolation of mycobacteria from clinical specimens and susceptibility testing of Mycobacterium tuberculosis

We compared the mycobacteria growth indicator tube (MGIT) system with the BACTEC 460 TB and Loewenstein-Jensen (LJ) systems for the recovery of mycobacteria (acid-fast bacilli [AFB]) from 600 clinical specimens. A total of 50 AFB (32 Mycobacterium tuberculosis complex, 10 M. avium complex, 3 M. gordonae, 3 M. xenopi, 1 M. terrae and 1 M. fortuitum) were detected. MGIT recovered 50 isolates of AFB (100% sensitivity), and BACTEC 460 TB and LJ recovered 49 (98% sensitivity) and 19 (38% sensitivity) AFB isolates, respectively. The mean times to detect mycobacteria were 10, 10 and 25 days for MGIT, BACTEC 460, and LJ slants. All isolates of M. tuberculosis complex were tested for susceptibility to streptomycin, isoniazid, rifampin, and ethambutol with the MGIT and BACTEC 460 TB. Both systems yielded identical susceptibility data with different mean times to report (5.38 days for MGIT versus 7.33 days for BACTEC 460 TB, P<0.05). The results suggest that MGIT is equivalent to BACTEC 460 TB in its ability to support the growth of mycobacteria, but significantly more efficient than LJ. MGIT may also be used for susceptibility testing of primary antituberculosis drugs.     

Copper complexes of imidazole-2-, pyrrole-2- and indol-3-carbaldehyde thiosemicarbazones: inhibitory activity against fungi and bacteria

Copper complexes of thiosemicarbazones of imidazole-2-carbaldehyde, pyrrole-2-carbaldehyde and indole-3-carbaldehyde were synthesised and characterised. The antimicrobial properties of the free ligands and their complexes were evaluated against yeasts, moulds and bacteria (Gram-positive and Gram-negative). Some copper chelates exhibited a moderate inhibitory activity, better than that of the corresponding free ligands. In particular, the pyrrole derivative [Cu(HL(2))(2)] proved to be a wide spectrum agent, showing an interesting inhibition of the growth of all Gram-positive bacteria and fungi tested at concentrations of 12-50 microg/mL. In contrast, a selective effect was observed for imidazole and indole chelates against fungi and Gram-positive bacteria, respectively.     

Oxidative DNA Damage and Activation of c-Jun N-Terminal Kinase Pathway in Fibroblasts from Patients with Hereditary Spastic Paraplegia

1.Hereditary spastic paraplegia (HSP) is a genetically heterogeneous group of neurodegenerative disorders affecting 1 in 10,000 individuals. The present study was aimed to elucidate the role played by reactive oxygen species (ROS) in the pathogenesis of this disease. 2. To address this question we used 7-11 passaged fibroblasts from HSP patients to measure the extent of DNA damage induced by H2O2 treatment and to evaluate the JNK phosphorylation level after hydrogen peroxide and serum stimuli. 3. The present study demonstrates that HSP cells compared to controls are more sensitive to DNA damages induced by H2O2 treatment, and that JNK phosphorylation levels are increased in HSP fibroblasts compared to controls after hydrogen peroxide and serum stimuli. These results suggest a ROS-mediated pathogenetic mechanism for this disease.     

Legionella waterline colonization: detection of Legionella species in domestic, hotel and hospital hot water systems

AIMS: An evaluation was made of the prevalence of Legionella species in hot water distribution systems in the city of Bologna (Italy) and their possible association with bacterial contamination (total counts and Pseudomonadaceae) and the chemical characteristics of the water (pH, Ca, Mg, Fe, Mn, Cu, Zn and Total Organic Carbon, TOC). METHODS AND RESULTS: A total of 137 hot water samples were analysed: 59 from the same number of private apartments, 46 from 11 hotels and 32 from five hospitals, all using the same water supply. Legionella species were detected in 40.0% of the distribution systems, L. pneumophila in 33.3%. The highest colonization was found in the hot water systems of hospitals (93.7% of samples positive for L. pneumophila, geometric mean: 2.4 x 10(3) CFU l(-1)), followed by the hotels (60.9%, geometric mean: 127.3 CFU l(-1)) and the apartments with centralized heating (41.9%, geometric mean: 30.5 CFU l(-1)). The apartments with independent heating systems showed a lower level of colonization (3.6% for Legionella species), with no evidence of L. pneumophila. Correlation analysis suggests that copper exerts an inhibiting action, while the TOC tends to favour the development of L. pneumophila. No statistically significant association was seen with Pseudomonadaceae, which were found at lower water temperatures than legionellae and in individual distribution points rather than in the whole network. CONCLUSIONS: The water recirculation system used by centralized boilers enhances the spreading of legionellae throughout the whole network, both in terms of the number of colonized sites and in terms of CFU count. SIGNIFICANCE AND IMPACT OF THE STUDY: Differences in Legionella colonization between types of buildings are not due to a variation in water supply but to other factors. Besides the importance of water recirculation, the study demonstrates the inhibiting action of copper and the favourable action of TOC on the development of L. pneumophila.     

Solution structure of the fifth and sixth transmembrane segments of the mitochondrial oxoglutarate carrier

The structures of the fifth and sixth transmembrane segments of the bovine mitochondrial oxoglutarate carrier (OGC) and of the hydrophilic loop that connects them were studied by CD and NMR spectroscopies. Peptides F215-R246, W279-K305 and P257-L278 were synthesized and structurally characterized. CD data showed that at high concentrations of TFE and SDS all peptides assume alpha-helical structures. (1)H-NMR spectra of the three peptides in TFE/water were fully assigned and the secondary structures of the peptides were obtained from nuclear Overhauser effects, (3)J(aH-NH) coupling constants and alphaH chemical shifts. The three-dimensional solution structures of the peptides were generated by distance geometry calculations. A well-defined alpha-helix was found in the region L220-V243 of peptide F215-R246 (TMS-V), in the region P284-M303 of peptide W279-K305 (TMS-VI) and in the region N261-F275 of peptide P257-L278 (hydrophilic loop). The helix L220-V243 exhibited a sharp kink at P239, while a little bend around P291 was observed in the helical region P284-M303. Fluorescence studies performed on peptide W279-K305, alone and together with other transmembrane segments of OGC, showed that the W279 fluorescence was quenched upon addition of peptide F215-R246, but not of peptides K21-K46, R78-R108 and P117-A149 suggesting a specific interaction between TMS-V and TMS-VI of OGC.