Blood lead levels, clinico-pathological findings and erythrocyte metabolism in dogs from different habitats

Biological markers of lead exposure were measured in 20 dogs from five different habitats chosen on the basis of the degree of anthropogenic influence. None of the dogs had clinical signs of lead poisoning. Compared to controls, blood lead concentrations were significantly higher in dogs from industrial areas, confirming the role of lead emissions in environmental pollution and the possible role of dogs as biomonitors of lead exposure in these areas. Whole blood lead concentrations were similar in dogs living in urban and rural areas, probably due to "indirect" lead sources and due to decreased urban lead contamination. As in humans, individual variability was detected. No significant correlation between clinico-pathological changes (hematology, clinical chemistry, Delta-aminolevulinic acid dehydratase activity and other intra-erythrocytic metabolic parameters) and lead concentration were observed. Our findings suggest dogs can be useful as sentinels of environmental lead exposure.     

Inner retinal abnormalities in a mouse model of Leber's congenital amaurosis

Leber's congenital amaurosis (LCA) is the earliest and most severe form in the world of genetic retinal dystrophy causing blindness. An animal model of LCA was recently created in which the cone-rod homeobox (crx) gene was disrupted using homologous recombination. Crx-/- mice display abnormal development of photoreceptors followed by their degeneration. We analyzed the morphology of inner retinal cells in crx-/- mice in order to evaluate the effects of abnormal photoreceptor development and death upon other retinal neurons. The identification of a time window during which inner retinal cells are still viable could be very important in view of the possibilities that photoreceptor transplantation or gene therapy might be used to restore vision in LCA. We used a combination of immunocytochemical and confocal microscopy techniques to screen the crx-/- inner retina and verify its morphological integrity after photoreceptor degeneration. We found significant morphological alterations in second-order neurons in crx-/- animals. The appearance of mutant retinas after photoreceptor death is indistinguishable from that of the retinal degeneration (rd/rd) mouse, a different genetic model of a retinal disease characterized by photoreceptor degeneration. However, at early stages of photoreceptor degeneration the morphology of retinal cells in the crx-/- mutant is considerably well preserved. It is likely that different genetic mechanisms that cause abnormal photoreceptor development and/or degeneration lead to a common pathway that determines second-order neuron modifications. The severity of modifications is linked to the timing of onset of the degeneration and appears to increase with time.     

Diffuse, micronodular lung disease. The high-resolution CT approach. A pictorial essay

Careful HRCT evaluation of the preferential distribution of micronodular lesions within the secondary lobule provides a fundamental contribution in the correct interpretation of the different associated patterns. This paper suggests a modern diagnostic algorithm that, together with clinical-anamnestic data and additional imaging features, is able to provide a definitive diagnosis or to reduce the possible differential diagnoses.     

Glucose-6-phosphate dehydrogenase expression associated with NADPH-dependent reactions in cerebellar neurons

This review describes the variation of glucose-6-phosphate dehydrogenase (G6PD) activity in the main neurons of the molecular and granular layers as well as in the deep nuclei of the cerebellum as observed so far by optical and electron microscopy studies. Light microscopy and semiquantitative microphotometry of histochemical staining showed that the highest G6PD activity was expressed by Purkinje cells and neurons of the deep cerebellar nuclei; the elements of the molecular layer showed a diffuse G6PD staining, while the granular layer displayed only scattered G6PD activity. Electron microscopy analysis showed that the basket and stellate cells, as well as the Golgi cells, have a remarkable G6PD activity, while in the granule cells the enzyme was barely detectable. The results show that cerebellar G6PD activity changes with different neuron types as a function of its role in sustaining NADPH dependent pathways in these cells.     

Expansion of tumor-specific CD8+ T cell clones in patients with relapsed myeloma after donor lymphocyte infusion

Donor lymphocyte infusions (DLI) provide effective therapy for patients with multiple myeloma who have relapsed after allogeneic bone marrow transplantation. However, the immunological mechanisms of the graft-versus-myeloma (GVM) effect have not been defined, and the target antigens of this response have not been identified. Molecular analysis of CDR3 Vbeta repertoire after CD4+ DLI demonstrated previously that the development of GVM and graft-versus-host-disease (GVHD) were associated with the clonal expansion of distinct T-cell populations in patient peripheral blood. In the current study, we undertook a molecular and functional characterization of GVM- and GVHD-associated T-cell clones. T-cell clones associated with GVM were detectable by clone-specific PCR at a low level in peripheral blood before DLI and expanded approximately 10-fold after DLI. In contrast, T-cell clones associated with GVHD were not detectable before DLI or before the development of clinical GVHD. Two T-cell clones associated with GVM were isolated and expanded in vitro, allowing their phenotypic and functional characterization. Both GVM clones were derived from donor cells and had a CD3+CD8+CD4- phenotype. One GVM clone specifically recognized patient myeloma cells in an HLA class I-restricted manner, but was not reactive with patient normal bone marrow cells or patient EBV transformed B cells. Taken together, these findings suggest that the GVM response is mediated by donor-derived CD8+ T-cell clones with antimyeloma specificity that may be present before DLI. In contrast, T-cell clones associated with GVHD are expanded de novo after DLI.     

Predictive variables for malignant transformation in 452 patients with asymptomatic IgM monoclonal gammopathy

The natural history of asymptomatic IgM monoclonal gammopathies (MG) and variables predicting evolution to symptomatic lymphoproliferative disorders were investigated in 452 patients diagnosed from 1975 to 2001. Univariate and multivariate Cox models were used to identify possible predictors of disease progression. At a median follow-up of 49 months (range, 12 to 233), 41 cases (9.1%) evolved to symptomatic Waldenstrom's macroglobulinemia (n = 36), non-Hodgkin's lymphoma (n = 2), B-cell chronic lymphocytic leukemia (n = 1), IgM multiple myeloma (n = 1), and primary amyloidosis (n = 1); the median interval from diagnosis was 53 months (range, 12 to 154). The cumulative probabilities of transformation into a symptomatic lymphoproliferative disease at 5 and 10 years were 8% (95% confidence interval [CI], 6% to 12%) and 21% (95% CI, 16% to 29%), respectively. At univariate analysis, monoclonal component size and hemoglobin level as continuous parameters, lymphocytosis (>4 x 10(9)/L), bone marrow lymphoplasmacytoid infiltration (>10%), erythrocyte sedimentation rate (>40 mm/h), and detectable Bence Jones proteinuria were significantly related with evolution probability. At multivariate analysis, paraprotein level (P <.0001), hemoglobin level (P <.05), and lymphocytosis (P <.0001) independently predicted malignant evolution (P <.0001). In conclusion, patients with asymptomatic IgM-MG showing hematological features predictive of progression should be carefully monitored in view of an early treatment of the disease.     

Effects of cannabinoids on non-adrenergic non-cholinergic-mediated relaxation in guinea-pig trachea

The effects of cannabinoid receptor agonists on the non-adrenergic non-cholinergic (NANC) inhibitory responses to electrical field stimulation in guinea-pig trachea were assessed. R-(+)-[2,3-dihydro-5-methyl-3-[(morpholilinyl) methyl]pyrrolo [1,2,3-de]-1,4-benzoxazin-6-yl]-(1-naphthalenyl)methanone mesylate (WIN 55,212-2; 10(-5) M) significantly enhanced the frequency-dependent response to electrical stimulation. The same concentration of R-(N)-(2-hydroxy-1-methylethyl)-5Z,8Z,11Z,14Z-eicosatetraenamide (R(+)methanandamide) and 1-propyl-2-methyl-3-(1-naphthoyl)indole (JWH-015) did not affect significantly the electrically induced inhibitory NANC responses. The effect of WIN 55,212-2 was not modified by the cannabinoid CB1 and CB2 receptor-selective antagonists, N-(piperidin-1-yl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide hydrochloride (SR141716A; 10(-5) M) and N-(1S)-endo-1,3,3-trimethyl bicyclo [2.2.1] heptan-2-yl]-5-(4-chloro-3-methylphenyl)-1-(4-methylbenzyl)-pyrazole-3-carboxamide (SR 144528; 10(-5) M), respectively. Moreover, the nitric oxide synthase inhibitor, L-NG-nitro-arginine methyl ester (L-NAME; 10(-4) M), but not the peptidase, alpha-chymotrypsin (2 U/ml), blocked the effect of WIN 55,212-2. Postsynaptically, WIN 55,212-2 did not produce any change of tracheal smooth muscle tone, either basal or histamine-induced, and did not interfere with the relaxant activity of the nitric oxide donor, sodium nitroprusside (10(-8)-10(-4) M). In conclusion, our results suggest that (a) cannabinoid CB1 and CB2 receptor stimulation does not alter the inhibitory NANC transmission in guinea-pig trachea, and (b) WIN 55,212-2 potentiates the NO-mediated component of the NANC relaxant response to electrical stimulation through a cannabinoid receptor-independent mechanism.     

Synthesis and pharmacological evaluation of new N-methyl-arylpyrrolidinols with analgesic activity

In the present paper, we report on the synthesis and antinociceptive activity of a new series of N-methyl-arylpyrrolidinols that we designed for a rational structure-activity relationship (SAR) study. The antinociceptive properties were investigated in vivo by the hot plate and formalin tests in mice and control on the locomotory activity was also monitored by the rota rod test. With this aim, the evaluation of the lipophilicity of all compounds was performed by the Daylight computational method in order to better understand the SAR. Interesting properties were proven for the compounds of the entire series.     

Highly potent 1,4-benzothiazine derivatives as K(ATP)-channel openers

A series of 1,4-benzothiazines, suitably functionalized at the N-4 and C-6 positions, arising from the replacement of a benzopyran-based structure of cromakalim with a 1,4-benzothiazine nucleus, has been synthesized as potassium channel openers (KCOs). Most of the tested compounds show high vasorelaxant potency that is considerably higher than that of the reference levcromakalim (LCRK). In the presence of the well-established selective K(ATP) blocker, glibenclamide, the vasorelaxing effects were antagonized in a competitive fashion, indicating the involvement of the K(ATP) channel in their pharmacological effect. Some aspects of the structure-activity relationship associated with the N-4 and C-6 substituents are discussed. The highest level of activity was achieved with a cyclopentenone ring at the N-4 position coupled with an electron-withdrawing group such as nitro, trifluoromethyl, or cyano at the C-6 position. Compounds 4c, 5c, and 6c displayed a vasorelaxant potency at least 10 000 times greater than that of LCRK, thus becoming the most potent KCOs identified to date.