RESUMEN
Soil microbial communities are dominated by a relatively small number of taxa that may play outsized roles in ecosystem functioning, yet little is known about their capacities to resist and recover from climate extremes such as drought, or how environmental context mediates those responses. Here, we imposed an in situ experimental drought across 30 diverse UK grassland sites with contrasting management intensities and found that: (1) the majority of dominant bacterial (85%) and fungal (89%) taxa exhibit resistant or opportunistic drought strategies, possibly contributing to their ubiquity and dominance across sites; and (2) intensive grassland management decreases the proportion of drought-sensitive and non-resilient dominant bacteria-likely via alleviation of nutrient limitation and pH-related stress under fertilisation and liming-but has the opposite impact on dominant fungi. Our results suggest a potential mechanism by which intensive management promotes bacteria over fungi under drought with implications for soil functioning.
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Ecosistema , Microbiota , Suelo , Pradera , Microbiología del Suelo , Conservación de los Recursos Naturales , Sequías , Bacterias/genéticaAsunto(s)
Fístula Bronquial , Fístula Cutánea , Enfermedades de los Perros , Animales , Fístula Bronquial/diagnóstico por imagen , Fístula Bronquial/cirugía , Fístula Bronquial/veterinaria , Fístula Cutánea/veterinaria , Enfermedades de los Perros/diagnóstico por imagen , Enfermedades de los Perros/cirugía , PerrosRESUMEN
BACKGROUND: Psoriasis is a common long-term, immune-mediated skin condition associated with behavioural factors (e.g. smoking, excess alcohol, obesity), which increase the risk of psoriasis onset, flares and comorbidities. Motivational interviewing (MI) is an evidence-based approach to health-related behaviour change that has been used successfully for patients with long-term conditions. This study assessed change in clinicians' MI skills and psoriasis knowledge following Psoriasis and Wellbeing (Pso Well® ) training. OBJECTIVES: To investigate whether the Pso Well training intervention improves clinicians' MI skills and knowledge about psoriasis-related comorbidities and risk factors; and to explore the acceptability and feasibility of the Pso Well training content, delivery and evaluation. METHODS: Clinicians attended the 1-day training programme focused on MI skills development in the context of psoriasis. MI skills were assessed pre- and post-training using the Behaviour Change Counselling Index. Knowledge about psoriasis-related comorbidity and risk factors was assessed with a novel 22-point measure developed for the study. Interviews with clinicians were analysed qualitatively to identify perceptions about the feasibility and acceptability of the training. RESULTS: Sixty-one clinicians completed the training (35 dermatology nurses, 23 dermatologists and three primary-care clinicians). Clinicians' MI skills (P < 0·001) and knowledge (P < 0·001) increased significantly post-training. Clinicians found the training valuable and relevant to psoriasis management. CONCLUSIONS: Attendance at the Pso Well training resulted in improvements in clinicians' knowledge and skills to manage psoriasis holistically. Clinicians deemed the training itself and the assessment procedures used both feasible and acceptable. Future research should investigate how this training may influence patient outcomes.
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Competencia Clínica/normas , Conocimientos, Actitudes y Práctica en Salud , Entrevista Motivacional/métodos , Psoriasis/terapia , Comunicación , Comorbilidad , Consejo , Dermatólogos/normas , Dermatología/educación , Educación Médica/métodos , Femenino , Humanos , Capacitación en Servicio , Masculino , Enfermeras y Enfermeros/normas , Satisfacción del Paciente , Relaciones Médico-Paciente , Médicos de Atención Primaria/normas , Factores de RiesgoRESUMEN
The majority of the Earth's terrestrial carbon is stored in the soil. If anthropogenic warming stimulates the loss of this carbon to the atmosphere, it could drive further planetary warming. Despite evidence that warming enhances carbon fluxes to and from the soil, the net global balance between these responses remains uncertain. Here we present a comprehensive analysis of warming-induced changes in soil carbon stocks by assembling data from 49 field experiments located across North America, Europe and Asia. We find that the effects of warming are contingent on the size of the initial soil carbon stock, with considerable losses occurring in high-latitude areas. By extrapolating this empirical relationship to the global scale, we provide estimates of soil carbon sensitivity to warming that may help to constrain Earth system model projections. Our empirical relationship suggests that global soil carbon stocks in the upper soil horizons will fall by 30 ± 30 petagrams of carbon to 203 ± 161 petagrams of carbon under one degree of warming, depending on the rate at which the effects of warming are realized. Under the conservative assumption that the response of soil carbon to warming occurs within a year, a business-as-usual climate scenario would drive the loss of 55 ± 50 petagrams of carbon from the upper soil horizons by 2050. This value is around 12-17 per cent of the expected anthropogenic emissions over this period. Despite the considerable uncertainty in our estimates, the direction of the global soil carbon response is consistent across all scenarios. This provides strong empirical support for the idea that rising temperatures will stimulate the net loss of soil carbon to the atmosphere, driving a positive land carbon-climate feedback that could accelerate climate change.
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Atmósfera/química , Ciclo del Carbono , Carbono/análisis , Geografía , Calentamiento Global , Suelo/química , Bases de Datos Factuales , Ecosistema , Retroalimentación , Modelos Estadísticos , Reproducibilidad de los Resultados , TemperaturaRESUMEN
The goal of this study was to identify susceptibility loci shared by schizophrenia (SZ) and bipolar disorder (BP), or specific to each. To this end, we performed a dense genome scan in a first sample of 21 multigenerational families of Eastern Quebec affected by SZ, BP or both (N=480 family members). This probably constitutes the first genome scan of SZ and BP that used the same ascertainment, statistical and molecular methods for the concurrent study of the two disorders. We genotyped 607 microsatellite markers of which 350 were spaced by 10 cM and 257 others were follow-up markers in positive regions at the 10 cM scan. Lander and Kruglyak thresholds were conservatively adjusted for multiple testings. We maximized the lod scores (mod score) over eight combinations (2 phenotype severity levels x 2 models of transmission x 2 analyses, affected/unaffected vs affected-only). We observed five genomewide significant linkages with mod score >4.0: three for BP (15q11.1, 16p12.3, 18q12-q21) and two for the shared phenotype, that is, the common locus (CL) phenotype (15q26,18q12-q21). Nine mod scores exceeded the suggestive threshold of 2.6: three for BP (3q21, 10p13, 12q23), three for SZ (6p22, 13q13, 18q21) and three for the CL phenotype (2q12.3, 13q14, 16p13). Mod scores >1.9 might represent confirmatory linkages of formerly reported genomewide significant findings such as our finding in 6p22.3 for SZ. Several regions appeared to be shared by SZ and BP. One linkage signal (15q26) appeared novel, whereas others overlapped formerly reported susceptibility regions. Despite the methodological limitations we raised, our data support the following trends: (i) results from several genome scans of SZ and BP in different populations tend to converge in specific genomic regions and (ii) some of these susceptibility regions may be shared by SZ and BP, whereas others may be specific to each. The present results support the relevance of investigating concurrently SZ and BP within the same study and have implications for the modelling of genetic effects.
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Trastorno Bipolar/genética , Predisposición Genética a la Enfermedad/genética , Genoma , Escala de Lod , Esquizofrenia/genética , Adulto , Cromosomas Humanos/genética , Familia , Femenino , Ligamiento Genético , Humanos , Masculino , Persona de Mediana Edad , Modelos Genéticos , QuebecRESUMEN
The Canadian lobster industry holds lobsters Homarus americanus in captivity for various periods to supply markets with live product year-round. Mortality during holding results in considerable losses, estimated at 10 to 15 % yr(-1) by the industry. This study examined the prevalence of Anophryoides haemophila and Aerococcus viridans, causative agents of 'bumper car' disease and gaffkemia, respectively, in lobsters freshly captured in the waters of Prince Edward Island during the spring and fall fishing seasons of 1997. A total of 116 lobsters were sampled in the spring, and 138 in the fall. A. haemophila was not detected in the spring, while the prevalence was 0.72 % in the fall with a 95% confidence interval (CI) of 0.02 to 3.97% and an overall prevalence of 0.39% (95% CI: 0.01 to 2.17%). The prevalence of A. viridans was estimated at 6.9% (95% CI: 3.0 to 13.14%) in the spring, 5.8% in the fall (95% CI: 2.54 to 11.10%), and 6.30% overall (95% CI: 3.64 to 10.03%). Because of the reduced interest in food of diseased lobsters, and compromised metabolism in the case of gaffkemia, these prevalence estimates are likely underestimates of the true prevalence of gaffkemia and 'bumper car' disease in the wild populations of lobster around Prince Edward Island.
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Cilióforos/aislamiento & purificación , Nephropidae/microbiología , Nephropidae/parasitología , Streptococcaceae/aislamiento & purificación , Animales , Cilióforos/patogenicidad , Femenino , Masculino , Prevalencia , Isla del Principe Eduardo/epidemiología , Estaciones del Año , Streptococcaceae/patogenicidadRESUMEN
We report the first stage of a genome scan of schizophrenia (SZ) and bipolar disorder (BP) covering 18 candidate chromosomal areas. In addition to testing susceptibility loci that are specific to each disorder, we tested the hypothesis that some susceptibility loci might be common to both disorders. A total of 480 individuals from 21 multigenerational pedigrees of Eastern Québec were evaluated by means of a consensus best-estimate diagnosis made blind to diagnoses in relatives and were genotyped with 220 microsatellite markers. Two-point and multipoint model-based linkage analyses were performed and mod scores (Z, for max Z(max)) are reported. The strongest linkage signals were detected at D18S1145 (in 18q12; Z = 4.03) for BP, and at D6S334 (in 6p 22-24; Z(het) = 3.47; alpha = 0.66) for SZ. Three other chromosomal areas (3q, 10p, and 21q) yielded linkage signals. Chromosomes 3p, 4p, 5p, 5q, 6q, 8p, 9q, 11q, 11p, 12q, 13q, 18p and 22q showed no evidence of linkage. The 18q12 results met the Lander and Kruglyak (1995) criterion for a genome-wide significant linkage and suggested that this susceptibility region may be shared by SZ and BP. The 6p finding provided confirmatory evidence of linkage for SZ. Our results suggest that both specific and common susceptibility loci must be searched for SZ and BP.
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Trastorno Bipolar/genética , Escala de Lod , Esquizofrenia/genética , Adulto , Cromosomas , Salud de la Familia , Femenino , Predisposición Genética a la Enfermedad , Genotipo , Humanos , Masculino , Repeticiones de Microsatélite , Persona de Mediana Edad , Fenotipo , QuebecRESUMEN
1,6-Naphthyridine-2-carboxylic acid benzylamides are potent anti-HCMV compounds. Replacement of the amide moiety by other groups containing internal hydrogen bonds was undertaken to extend the SAR. Our results indicated that the urca derivatives showed very good activity.
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Antivirales/síntesis química , Citomegalovirus/efectos de los fármacos , Naftiridinas/farmacología , Tioamidas/farmacología , Antivirales/farmacología , Supervivencia Celular/efectos de los fármacos , Diseño de Fármacos , Enlace de Hidrógeno , Concentración 50 Inhibidora , Naftalenos/química , Naftiridinas/síntesis química , Relación Estructura-Actividad , Tioamidas/síntesis química , Tioamidas/químicaRESUMEN
Substituted 1,6-naphthyridine derivatives, a new class of human cytomegalovirus inhibitors, were prepared to demonstrate the role of intramolecular hydrogen bonds to maintain the compounds in their active conformation.
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Antivirales/química , Antivirales/farmacología , Citomegalovirus/efectos de los fármacos , Naftiridinas/química , Naftiridinas/farmacología , Citomegalovirus/química , Humanos , Concentración 50 Inhibidora , Pruebas de Sensibilidad Microbiana , Modelos Moleculares , Conformación Molecular , Relación Estructura-ActividadRESUMEN
Structure-activity relationship studies on our newly identified anti-HCMV compounds, the 1,6-naphthyridines led to the identification of isoquinoline-6-carboxamides as potent and selective anti-HCMV agents.
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Antivirales/farmacología , Citomegalovirus/efectos de los fármacos , Isoquinolinas/farmacología , Antivirales/química , Isoquinolinas/química , Pruebas de Sensibilidad Microbiana , Relación Estructura-ActividadAsunto(s)
Antivirales/síntesis química , Citomegalovirus/efectos de los fármacos , Naftiridinas/síntesis química , Antivirales/química , Antivirales/farmacología , Antivirales/toxicidad , Línea Celular , Humanos , Concentración 50 Inhibidora , Naftiridinas/química , Naftiridinas/farmacología , Naftiridinas/toxicidad , Relación Estructura-ActividadRESUMEN
Pyrido [1,2a] indole derivatives were identified as potent inhibitors of human immunodeficiency virus type 1 (HIV-1) replication during a random screening programme. The compounds showed no antiviral activity against HIV-2 or in cells chronically infected with HIV-1, but had good inhibitory effect against purified HIV-1 reverse transcriptase (RT) in an in vitro assay. They were therefore classified as non-nucleoside RT inhibitors (NNRTI). The synthesis of additional compounds of the same class revealed a structure-activity relationship. The most potent compound of the series, BCH-1, had similar antiviral activity to the licensed NNRTI nevirapine against laboratory strains of HIV-1 cultured in cell lines and primary clinical isolates of HIV-1 cultured in peripheral blood mononuclear cells. However, BCH-1 showed greater cytotoxicity, providing a narrow selectivity index in the order of 35. BCH-1 had equivalent antiviral activity against viruses resistant to the nucleoside RT inhibitors zidovudine, didanosine and lamivudine and maintained better activity (less than threefold change in IC50) than nevirapine against viruses resistant to a range of NNRTIs with the single amino acid changes L100I, K103N, E138K or Y181C in the RT. Viruses with single V106A or Y188C amino acid changes showed five- and 10-fold resistance to BCH-1, respectively, in contrast to nevirapine, which had a > 100-fold change in IC50. However, virus with both V106A and Y188C amino acid changes showed higher level resistance (> 15-fold) to BCH-1. Virus with > 10-fold resistance to BCH-1 was rapidly selected for after growth in increasing concentrations of compound and was shown to be cross-resistant to nevirapine. Sequencing of this virus revealed two amino acid changes at positions 179 (V to D) and 181 (Y to C) in the RT. BCH-1 represents a new class of NNRTI, which may act as a lead to identify more selective compounds.
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Fármacos Anti-VIH/farmacología , VIH-1/efectos de los fármacos , Indoles/farmacología , Piridonas , Piridonas/farmacología , Inhibidores de la Transcriptasa Inversa/farmacología , Sustitución de Aminoácidos , Secuencia de Bases , Línea Celular , Cartilla de ADN , Farmacorresistencia Microbiana/genética , Transcriptasa Inversa del VIH/química , Transcriptasa Inversa del VIH/genética , VIH-1/enzimología , VIH-1/fisiología , Humanos , Indoles/química , Pruebas de Sensibilidad Microbiana , Reacción en Cadena de la Polimerasa , Piridonas/química , Replicación Viral/efectos de los fármacosRESUMEN
The aim of this study was to develop an automated system of cell recognition based upon colour analysis suitable for microscopic examination of bronchial inflammation. Human bronchi obtained from 17 patients undergoing thoracotomy were embedded in glycolmethacrylate to perform immunohistochemistry with antibodies against: neutrophil elastase, tryptase, chymase, eosinophil cationic protein, CD68, CD3 and immunoglobulin E. The image analysis system calculates three independent criteria (optic density, hue density, hue) combined with morphological parameters to specifically recognize a positive staining. This automated analysis was applied to the study of bronchial inflammation in smokers and nonsmokers in terms of the absolute number of cells and the expression of different markers by a single cell. The use of these criteria enabled the characterization of a positive stain on single (intraclass correlation coefficient (ICC) = 0.88 or serial (ICC = 0.84) sections. Cell counts obtained by the automated system were highly reproducible. Regarding bronchial inflammation, it was found that the number of inflammatory cells was significantly higher in smokers than in nonsmokers, the majority of these cells bearing immunoglobulin E. These results demonstrate that such computerized analysis of colours is a valuable method for quantifying inflammatory cells in bronchial tissue and for analysing the expression of different markers by a single cell.
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Bronquios/patología , Bronquitis/patología , Líquido del Lavado Bronquioalveolar/citología , Interpretación de Imagen Asistida por Computador , Anciano , Autoanálisis , Bronquios/citología , Calibración , Recuento de Células , Color , Técnicas de Cultivo , Estudios de Evaluación como Asunto , Femenino , Humanos , Inmunohistoquímica , Masculino , Microscopía/métodos , Persona de Mediana Edad , Reproducibilidad de los Resultados , Mucosa Respiratoria/patología , Sensibilidad y EspecificidadRESUMEN
There is a paucity of studies in the literature concerning the structural characteristics of the arterial wall in the abdominal region using human material and specialized morphometric techniques. In the present study we carry out the morphometric study, describing a series of structural peculiarities in 12 segments of the human splenic artery. Among these the presence of length-wise or spiral-shaped muscular columns in the medial layer which mark and reduce the diameter of the arterial lumen is of major importance. In its underlying intima small localized thickenings appear which, with age may become generalized. We also analyze the different intimal thickenings and such indices as the Intimal Thickening Index, Lumen Reduction Index and Pathologic Thickening Index, with differences among the groups we have considered. The study of elastin in the various parietal structures help us to understand the possible pathogenesis of the thickenings, and to clarify the important morphological-functional correlation for the regulation of blood flow which exists in this arterial region.
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Músculo Liso Vascular/anatomía & histología , Arteria Esplénica/anatomía & histología , Adolescente , Adulto , Biometría , Tejido Elástico/anatomía & histología , Humanos , Persona de Mediana Edad , Arteria Esplénica/crecimiento & desarrolloRESUMEN
OBJECTIVE: The reliability and accuracy of the best-estimate diagnostic procedure were examined, and factors associated with reliability were determined. METHOD: The subjects were 134 members of large multigenerational pedigrees densely affected by bipolar disorders or schizophrenia. Three best-estimate diagnoses were derived: first, by a research psychiatrist and research assistant unblind to the relatives' diagnoses; second, by two blind independent psychiatrists; third, by a panel of four blind psychiatrists. The subjects were characterized on several clinical and methodological variables, which were used to compare the agreements of two types of best-estimate diagnoses with the disagreements. RESULTS: There was satisfactory agreement between the unblind and blind consensus best-estimate diagnoses and between the two blind independent psychiatrists. Latent class analyses revealed that limited sensitivity was the main source of imperfect reliability. Confusability analyses revealed that the most problematic diagnostic distinctions involved schizoaffective disorder, which was confused with schizophrenia, bipolar I disorder, and schizophreniform disorder. Blindness significantly affected diagnostic outcome in latent class analyses. Moreover, for diagnostic disagreements, unblind diagnoses had greater continuity with the most predominant diagnosis in the pedigree than did blind diagnoses. Diagnostic disagreements were associated with the presence of mixed affective and psychotic symptoms, less diagnostic certainty, and shorter duration of illness. CONCLUSIONS: These results suggest that it is possible to identify cases that are more likely to lead to diagnostic disagreements in family and epidemiological studies and that blind diagnoses may help to prevent false positive diagnoses, which may be particularly detrimental to genetic linkage analyses.
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Familia , Registros Médicos , Trastornos Mentales/diagnóstico , Escalas de Valoración Psiquiátrica/estadística & datos numéricos , Adulto , Trastorno Bipolar/diagnóstico , Trastorno Bipolar/epidemiología , Trastorno Bipolar/genética , Diseño de Investigaciones Epidemiológicas , Reacciones Falso Positivas , Femenino , Ligamiento Genético , Humanos , Masculino , Registros Médicos/estadística & datos numéricos , Trastornos Mentales/epidemiología , Trastornos Mentales/genética , Persona de Mediana Edad , Linaje , Prevalencia , Escalas de Valoración Psiquiátrica/normas , Trastornos Psicóticos/diagnóstico , Trastornos Psicóticos/epidemiología , Trastornos Psicóticos/genética , Reproducibilidad de los Resultados , Proyectos de Investigación/normas , Esquizofrenia/diagnóstico , Esquizofrenia/epidemiología , Esquizofrenia/genética , Sensibilidad y EspecificidadRESUMEN
Recent reports of a linkage trend in 6p24-22 for schizophrenia (SZ), in different samples, were tempered by the concurrent evidence of negative reports in other samples. In the studies showing positive results, different definitions of affection and a wide spectrum of diagnoses were used. Our objectives were not only to test for linkage at 6p24-22 in the Eastern Quebec population, but also to test whether this putative vulnerability locus was either selectively linked to schizophrenia (SZ), or to bipolar disorder (BP), or to both major psychoses. Parametric and nonparametric linkage analyses with 12 microsatellite markers in 6p24-p22 were performed on a sample of 18 large multigenerational pedigrees (N = 354) either affected by SZ, or by BP, or equally affected by both major psychoses (i.e., mixed pedigrees). Three affection definitions were usually tested in our program: one on schizophrenia (SZ), one on bipolar disorder (BP), and one that comprised SZ and BP under the hypothesis of a susceptibility locus common to both in major psychoses (common locus, CL). The results of parametric analyses did not support a major gene hypothesis. However, in one large mixed pedigree (#151), we observed with the common locus phenotype (CL) lod scores of 2.49 and 2.15, respectively, at the D6S296 and D6S277 loci under a dominant model. Our data suggest the presence of a potential vulnerability locus at 6p24-22 that could be related to both schizophrenia and bipolar affective disorder. These results may be seen as congruent with former studies that used schizoaffective as well as schizophrenia diagnoses as entry criteria for the affected families, and used an affection definition that comprised affective psychoses as well as schizophrenia.
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Cromosomas Humanos Par 6/genética , Ligamiento Genético , Trastornos Psicóticos/genética , Trastorno Bipolar/genética , Mapeo Cromosómico , Femenino , Genotipo , Humanos , Escala de Lod , Masculino , Repeticiones de Microsatélite/genética , Linaje , Fenotipo , Recombinación Genética , Esquizofrenia/genéticaRESUMEN
The in-vitro activities of omeprazole and three antimicrobial agents against 89 clinical isolates of Helicobacter pylori from a population with duodenal ulcer disease were determined by an agar dilution method. Resistance rates were 20% for metronidazole (MIC > 8 mg/L), 1% for clarithromycin (MIC > 2 mg/L) and zero for ampicillin (MIC > 8 mg/L). Omeprazole was relatively active against H. pylori in vitro (MIC < or = 8 mg/L).
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Ampicilina/farmacología , Antibacterianos/farmacología , Claritromicina/farmacología , Helicobacter pylori/efectos de los fármacos , Metronidazol/farmacología , Omeprazol/farmacología , Úlcera Duodenal/microbiología , Helicobacter pylori/aislamiento & purificación , Humanos , Pruebas de Sensibilidad Microbiana , QuebecRESUMEN
OBJECTIVE: To report in vitro susceptibilities of penicillin-susceptible and penicillin-intermediate Streptococcus pneumoniae isolates to cephalosporins, vancomycin and teicoplanin. DESIGN: Minimal inhibitory concentrations (mic) were determined according to National Committee for Clinical Laboratory Standards guidelines for 17 penicillin-susceptible isolates (mic 0.06 mg/L or less) and 16 isolates showing intermediate susceptibility to penicillin (mic 0.12 to 1.0 mg/L). SETTING: Tertiary care university centre. MAIN RESULTS: Comparison of the mic(90) values with those of other antibiotics tested demonstrated that ceftriaxone, cefotaxime and teicoplanin were the most active agents against penicillin-susceptible strains. However, teicoplanin had the lowest mic and was superior to other agents against strains with intermediate penicillin susceptibility. The mics of all cephalosporins increased in concordance with the mic of penicillin. CONCLUSION: Isolates demonstrating intermediate susceptibility or resistance to penicillin should be routinely evaluated for susceptibility to clinically important cephalosporins.
RESUMEN
The microsomal fraction from the testes of immature pigs can convert pregnenolone to 17-hydroxypregnenolone and also to 5,16-androstadien-3 beta-ol (andien-beta). The available evidence supports the hypothesis that both these reactions are catalysed by one enzyme, cytochrome-P450(17 alpha). In the absence of cytochrome b5, 17-hydroxypregnenolone will be the major product but that if cytochrome b5 is present in sufficient quantity, andien-beta becomes a major product. The point of divergence between the conversion of pregnenolone to either 17-hydroxypregnenolone or andien-beta was investigated using enzyme kinetic analysis to determine whether 16 alpha-hydroxypregnenolone, 20 beta-hydroxypregnenolone or 16-dehydropregnenolone could be specific intermediates to one reaction or the other. Product inhibition by 17-hydroxypregnenolone and andien-beta was competitive for both 17-hydroxylase and "andien-beta synthetase" supporting the current view of a common active site for both reactions. 16 alpha-Hydroxypregnenolone was a very poor competitive inhibitor of 17-hydroxylase and andien-beta synthetase with Ki(app) values many fold greater than the Km(app) for pregnenolone or the Ki(app) for reaction product, rendering it unlikely that 16 alpha hydroxylation is a key intermediary step in either pathway. 20 beta-Hydroxypregnenolone was a more potent inhibitor of andien-beta synthetase than of 17-hydroxylase and for the latter enzyme activity, the Ki(app) was lower than that for 17-hydroxypregnenolone itself. However, for andien-beta synthetase, 20 beta-hydroxypregnenolone may be an early intermediate as the Ki(app) was consistent with the affinity for the active site being intermediate between the Km(app) for pregnenolone and the Ki(app) for andien-beta. 16-Dehydropregnenolone was equipotent at inhibiting 17-hydroxylase and andien-beta synthetase activities suggesting that 16-dehydropregnenes may be involved in the stages immediately prior to C21 side-chain cleavage.
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Sistema Enzimático del Citocromo P-450/metabolismo , Oxidorreductasas/metabolismo , Pregnenolona/metabolismo , Esteroide 17-alfa-Hidroxilasa/metabolismo , Testículo/enzimología , Androstenoles/farmacología , Animales , Animales Recién Nacidos , Sitios de Unión , Inhibidores Enzimáticos del Citocromo P-450 , Deshidroepiandrosterona/farmacología , Técnicas In Vitro , Cinética , Masculino , Microsomas/enzimología , Oxidorreductasas/antagonistas & inhibidores , Pregnenolona/análogos & derivados , Pregnenolona/farmacología , Esteroide 17-alfa-Hidroxilasa/antagonistas & inhibidores , PorcinosRESUMEN
BACKGROUND: The general way to differentiate objects in a field is to stain each of them specifically with a different dye, as the eye can easily discriminate colors. The use of specific dyes or immunohistochemical staining associated with an automated image analysis facilitates the quantitation of differently Colored objects. EXPERIMENTAL DESIGN: Rabbit aortic smooth muscle cells were seeded in culture conditions. When the cells reach confluence, they can be stained by immunocytochemistry. We were able to compare four different variables of immunostaining of two antigens in the same preparation. Antigenic expression was detected after double immunocytochemical staining, alkaline phosphatase, or peroxidase, and each antigen was stained sequentially by either enzyme. RESULTS: We have developed an approach to a nondestructive and noncolored limited quantitative method, that allows a strict analysis on the same view of two defined colors. We used the system of intensity, hue, and saturation to digitize colored video image. The distribution of these two antigens, alpha-actin and 2P1A2 both specific of smooth muscle cell, was quantitatively analyzed, and was not affected by the sequence of staining. CONCLUSIONS: This technique opens new possibilities for pathologists to compare antigenic distribution after immunocytochemical labeling. This can be extended to other dyes on histologic sections and to facilitate diagnosis.