Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Resultados 1 - 20 de 37
Filtrar
1.
Mol Psychiatry ; 15(2): 166-76, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-18663369

RESUMEN

Panic disorder (PD) and social anxiety disorder (SAD) are moderately heritable anxiety disorders. We analyzed five genes, derived from pharmacological or translational mouse models, in a new case-control study of PD and SAD in European Americans: (1) the serotonin transporter (SLC6A4), (2) the serotonin receptor 1A, (3) catechol-O-methyltransferase, (4) a regulator of g-protein signaling and (5) the gastrin-releasing peptide receptor. Cases were interviewed using the schedule for affective disorders and schizophrenia and were required to have a probable or definite lifetime diagnosis of PD (N=179), SAD (161) or both (140), with first onset by age 31 and a family history of anxiety. Final diagnoses were determined using the best estimate procedure, blind to genotyping data. Controls were obtained from the National Institute of Mental Health Human Genetics Initiative; only subjects above 25 years of age who screened negative for all psychiatric symptoms were included (N=470). A total of 45 single nucleotide polymorphisms were successfully genotyped over the five selected genes using Applied Biosystems SNPlex protocol. SLC6A4 provided strong and consistent evidence of association with the PD and PD+SAD groups, with the most significant association in both groups being at rs140701 (chi(2)=10.72, P=0.001 with PD and chi(2)=8.59, P=0.003 in the PD+SAD group). This association remained significant after multiple test correction. Those carrying at least one copy of the haplotype A-A-G constructed from rs3794808, rs140701 and rs4583306 have 1.7 times the odds of PD than those without the haplotype (95% confidence interval: 1.2-2.3). The SAD only group did not provide evidence of association, suggesting a PD-driven association. The findings remained after adjustment for age and sex, and there was no evidence that the association was due to population stratification. The promoter region of the gene, 5-HTTLPR, did not provide any evidence of association, regardless of whether analyzed as a triallelic or biallelic locus, nor did any of the other four candidate genes tested. Our findings suggest that the serotonin transporter gene may play a role in PD; however, the findings require replication. Future studies should attend to the entire genetic region rather than the promoter.


Asunto(s)
Predisposición Genética a la Enfermedad , Trastorno de Pánico/genética , Polimorfismo de Nucleótido Simple/genética , Regiones Promotoras Genéticas/genética , Proteínas de Transporte de Serotonina en la Membrana Plasmática/genética , Adolescente , Adulto , Anciano , Femenino , Estudio de Asociación del Genoma Completo , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Trastornos Fóbicos/genética , Receptor de Serotonina 5-HT1A/genética , Adulto Joven
2.
Arch Gen Psychiatry ; 51(5): 383-94, 1994 May.
Artículo en Inglés | MEDLINE | ID: mdl-8179462

RESUMEN

BACKGROUND: Panic disorder and major depression (MDD) are both highly familial disorders that co-occur in individuals but do not cosegregate in families. Evidence concerning their familial aggregation with other psychiatric disorders, including phobias, substance abuse, and antisocial personality, has been contradictory. In part, the contradictory findings may be due to failure to account for the effects of proband comorbidity on risks in relatives. METHODS: A family study of 1047 adult first-degree relatives of 193 probands in four diagnostic groups (panic disorder without MDD, panic disorder plus MDD, early-onset MDD, and screened normal controls) was used to determine the range of psychiatric disorders associated with panic disorder and MDD and the effects of proband comorbidity on the rates of disorders in relatives. RESULTS: Compared to relatives of normal controls, relatives of probands with panic disorder or panic disorder and MDD showed significantly increased risks of panic disorder, but relatives of probands with early-onset MDD did not. After proband comorbidity was controlled for, relatives of probands with panic disorder were also at a significantly increased risk for social phobia but not for any other psychiatric disorders. Relatives of probands with early-onset MDD were at significantly increased risk for MDD, dysthymia, abuse of or dependence on alcohol and other drugs, and antisocial personality disorders but not for any other psychiatric disorders. CONCLUSIONS: We conclude that panic disorder is a specific familial entity that is not associated with a broad range of other anxiety or other psychiatric disorders, with the possible exception of social phobia. Dysthymia, substance abuse, and antisocial personality appear to be on the spectrum of early-onset MDD.


Asunto(s)
Trastorno Depresivo/epidemiología , Familia , Trastornos Mentales/epidemiología , Trastorno de Pánico/epidemiología , Adolescente , Adulto , Factores de Edad , Alcoholismo/epidemiología , Alcoholismo/genética , Trastorno de Personalidad Antisocial/epidemiología , Trastorno de Personalidad Antisocial/genética , Comorbilidad , Trastorno Depresivo/genética , Femenino , Humanos , Masculino , Trastornos Mentales/genética , Persona de Mediana Edad , Trastorno de Pánico/genética , Trastornos Fóbicos/epidemiología , Trastornos Fóbicos/genética , Modelos de Riesgos Proporcionales , Factores de Riesgo , Factores Sexuales , Trastornos Relacionados con Sustancias/epidemiología , Trastornos Relacionados con Sustancias/genética
3.
Arch Gen Psychiatry ; 50(10): 767-80, 1993 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-8215801

RESUMEN

OBJECTIVE: The comorbidity between panic disorder and major depression (MDD) in individuals has been amply documented. However, data from family studies to determine whether panic disorder and MDD aggregate separately or together in families have been inconclusive, in part because of the absence of studies with the full range of proband groups. This report presents results from a family study with the necessary mutually exclusive groups: panic disorder without MDD, panic disorder with MDD, MDD without panic disorder, and normal controls. METHODS: Diagnostic information was obtained from 193 probands and 1047 of their adult relatives with the Schedule for Affective Disorders and Schizophrenia--Lifetime Version for Anxiety Disorders by direct interview, and/or from multiple informants, without knowledge of proband diagnoses. Best-estimate diagnoses were based on all available information by clinicians independently of data collection and without knowledge of probands' and other relatives' status. RESULTS: Findings indicated the specific and independent transmission of panic disorder and MDD, the separation of panic disorder from MDD, and the nonfamilial nature of late-onset MDD. The pattern of results was unaffected by the use of different diagnostic criteria, number of informants, interview status of relatives, presence of substance abuse or agoraphobia or the sequence of MDD and panic disorder in probands, or whether probands were selected from treatment clinics or community sample. CONCLUSIONS: We conclude that panic disorder and MDD are separate disorders with substantial co-occurrence in individuals, and that panic comorbid with MDD is not a single, distinct disorder. Finally, we illustrate an approach to examining comorbidity in family data through analysis of mutually exclusive, parallel diagnoses in probands and relatives.


Asunto(s)
Trastorno Depresivo/epidemiología , Familia , Trastorno de Pánico/epidemiología , Adolescente , Adulto , Agorafobia/diagnóstico , Agorafobia/epidemiología , Comorbilidad , Intervalos de Confianza , Recolección de Datos , Trastorno Depresivo/diagnóstico , Trastorno Depresivo/genética , Diagnóstico Diferencial , Femenino , Humanos , Masculino , Persona de Mediana Edad , Oportunidad Relativa , Trastorno de Pánico/diagnóstico , Trastorno de Pánico/genética , Proyectos de Investigación , Riesgo , Trastornos Relacionados con Sustancias/diagnóstico , Trastornos Relacionados con Sustancias/epidemiología
4.
Am J Med Genet ; 81(2): 139-47, 1998 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-9613853

RESUMEN

Panic disorder is characterized by spontaneous and recurrent panic attacks, often accompanied by agoraphobia. The results of family, twin, and segregation studies suggest a genetic role in the etiology of the illness. We have genotyped up to 23 families that have a high density of panic disorder with 540 microsatellite DNA markers in a first-pass genomic screen. The thirteen best families (ELOD > 6.0 under the dominant genetic model) have been genotyped with an ordered set of markers encompassing all the autosomes, at an average marker density of 11 cM. Over 110,000 genotypes have been generated on the whole set of families, and the data have been analyzed under both a dominant and a recessive model, and with the program SIBPAIR. No lod scores exceed 2.0 for either parametric model. Two markers give lod scores over 1.0 under the dominant model (chromosomes 1p and 20p), and four do under the recessive model (7p, 17p, 20q, and X/Y). One of these (20p) may be particularly promising. Analysis with SIBPAIR yielded P values equivalent to a lod score of 1.0 or greater (i.e., P < .016, one-sided, uncorrected for multiple tests) for 11 marker loci (2, 7p, 8p, 8q, 9p, 11q, 12q, 16p, 20p and 20q).


Asunto(s)
Trastorno de Pánico/genética , Adolescente , Adulto , Niño , Cromosomas Humanos Par 20 , Familia , Femenino , Genes Dominantes , Genes Recesivos , Ligamiento Genético , Marcadores Genéticos , Pruebas Genéticas , Genotipo , Humanos , Escala de Lod , Masculino , Repeticiones de Microsatélite , Persona de Mediana Edad , Trastorno de Pánico/epidemiología
5.
J Am Acad Child Adolesc Psychiatry ; 34(4): 445-53, 1995 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-7751258

RESUMEN

OBJECTIVE: To assess critically the efficacy and safety of lithium and replicate earlier findings in a larger sample of aggressive children with conduct disorder and to assess the utility of the Profile of Mood States (POMS) in this population. METHODS: Children hospitalized for treatment-refractory severe aggressiveness and explosiveness and with diagnosed conduct disorder were subjects in this double-blind, placebo-controlled clinical trial. After a 2-week placebo baseline period, children were randomly assigned to lithium or placebo treatment for 6 weeks of placebo. The main outcome measures were the Global Clinical Judgments (Consensus) Scale, Children's Psychiatric Rating Scale, Conners Teacher Questionnaire, Parent-Teacher Questionnaire, and the POMS. RESULTS: Fifty children (mean age 9.4 years) completed this study. The mean optimal daily dose of lithium was 1,248 mg and the mean serum level was 1.12 mEq/L. Lithium was superior to placebo, although the effects on some measures were more modest than in a previous study. CONCLUSIONS: Lithium appears to be an effective treatment for some severely aggressive children with conduct disorder. Although the POMS appeared to be reliable, it did not detect any response to lithium.


Asunto(s)
Agresión/efectos de los fármacos , Trastornos de la Conducta Infantil/tratamiento farmacológico , Carbonato de Litio/administración & dosificación , Admisión del Paciente , Agresión/psicología , Niño , Trastornos de la Conducta Infantil/psicología , Preescolar , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Esquema de Medicación , Femenino , Humanos , Carbonato de Litio/efectos adversos , Masculino , Determinación de la Personalidad , Resultado del Tratamiento
6.
J Am Acad Child Adolesc Psychiatry ; 36(6): 835-43, 1997 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-9183140

RESUMEN

OBJECTIVE: To report results from a long-term prospective study of safety of haloperidol treatment and prevalence of haloperidol-related dyskinesias. METHOD: Subjects were children with autism requiring pharmacotherapy for target symptoms. After baseline assessments, children received haloperidol treatment; responders requiring further treatment were considered for enrollment into the present study. Six-month haloperidol treatment periods were followed by a 4-week placebo period. The procedure was repeated if further haloperidol treatment was required. At specified times children were evaluated by using multiple instruments. RESULTS: Between 1979 and 1994, 118 children aged 2.3 to 8.2 years participated in the study. The mean dose of haloperidol was 1.75 mg/day. Mainly withdrawal dyskinesias (WD) developed in 40 (33.9%) children; 20 had more than one dyskinetic episode. A subgroup that remained significantly longer in the study and had a significantly higher cumulative dose of haloperidol evidenced a significantly higher incidence of WD. Occurrence rates of tardive dyskinesia (TD) and multiple episodes of TD/WD were higher among girls. CONCLUSION: Female gender and pre- and perinatal complications may be involved in susceptibility to dyskinesias; greater cumulative haloperidol dose and/or longer exposure to haloperidol may increase the risk.


Asunto(s)
Antipsicóticos/efectos adversos , Trastorno Autístico/tratamiento farmacológico , Discinesia Inducida por Medicamentos , Haloperidol/efectos adversos , Niño , Preescolar , Femenino , Humanos , Estudios Longitudinales , Masculino , Estudios Prospectivos
7.
J Am Acad Child Adolesc Psychiatry ; 35(4): 537-44, 1996 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-8919717

RESUMEN

OBJECTIVE: To assess the short-term efficacy and safety of clomipramine in hospitalized young children with autism. METHOD: This was an open pilot study; after a 1-week placebo baseline, subjects were treated with clomipramine for 5 weeks. Dosage was individually regulated; starting dose was 25 mg/day; increments were 25 mg/day. Maximum dose was 250 mg/day or 5.0 mg/kg per day, whichever was less. Multiple raters, under several conditions, used the Children's Psychiatric Rating Scale, Clinical Global Impressions, Conners Parent Teacher Questionnaire, and the Clinical Global Consensus Ratings. RESULTS: Eight children, aged 3.5 to 8.7 years, were enrolled in the study; seven of these completed the study. A 3.5-year-old boy was excluded during the third week of treatment after having urinary retention on two occasions. At doses ranging from 2.50 to 4.64 mg/kg per day (mean = 3.14), one child improved moderately and six were rated as worse on the Clinical Global Consensus Ratings. Untoward effects were common. CONCLUSIONS; Clomipramine was not therapeutic and was associated with serious untoward effects in this sample. Young autistic children may be more prone to experience untoward effects than older patients.


Asunto(s)
Trastorno Autístico/tratamiento farmacológico , Clomipramina/uso terapéutico , Inhibidores Selectivos de la Recaptación de Serotonina/uso terapéutico , Niño , Preescolar , Clomipramina/farmacología , Femenino , Humanos , Masculino , Análisis por Apareamiento , Proyectos Piloto , Inhibidores Selectivos de la Recaptación de Serotonina/farmacología
8.
Psychiatry Res ; 57(2): 169-80, 1995 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-7480383

RESUMEN

Family history, a risk factor for psychiatric disorders, is infrequently assessed in epidemiologic studies due to time and cost constraints. We designed a brief computer-scorable instrument, the Family History Screen for Epidemiologic Studies (FHE), which collects a pedigree and screens for 15 DSM-III diagnoses in an informant and in his family members. The FHE was administered to one informant in 77 families in which we had collected pedigrees, interviewed 77 informants and 239 relatives using the Lifetime Anxiety version of the schedule for Affective Disorders and Schizophrenia or the Epidemiologic version of the Schedule for Affective Disorders and Schizophrenia for School-Aged Children, and performed best-estimate diagnoses. We evaluated the accuracy with which the FHE predicted best-estimate diagnoses. For adults reporting on themselves, the FHE demonstrated high levels of sensitivity and specificity for depression (67.4, 75.0) and panic (92.5, 89.2), and low sensitivity and high specificity for substance abuse (33.3, 93.6). For informants reporting on adult relatives, sensitivity was low and specificity was high for depression (35.2, 84.9), panic (20.0, 91.7), and substance abuse (42.1, 93.4). For informants reporting on children, perhaps due to lower prevalence, sensitivity and specificity were poor. The FHE is a good screen for psychiatric disorders in adult informants, but it is not useful for family history. It may be useful in primary care medical settings as a screen for psychiatric history.


Asunto(s)
Trastornos de Ansiedad/epidemiología , Trastornos de Ansiedad/genética , Trastorno Depresivo/epidemiología , Trastorno Depresivo/genética , Trastornos Relacionados con Sustancias/epidemiología , Trastornos Relacionados con Sustancias/genética , Adolescente , Adulto , Trastornos de Ansiedad/diagnóstico , Niño , Trastorno Depresivo/diagnóstico , Femenino , Humanos , Masculino , Linaje , Proyectos Piloto , Escalas de Valoración Psiquiátrica , Trastornos Relacionados con Sustancias/diagnóstico
9.
Lipids ; 31 Suppl: S157-61, 1996 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-8729112

RESUMEN

In this study of 20 moderately to severely depressed patients, diagnosed using current research diagnostic criteria and excluding known bipolar affective disorder and reactive depression, we investigated relationships between severity of depression and levels and ratios of n-3 and n-6 long-chain polyunsaturated fatty acids (PUFA) in plasma and erythrocyte phospholipids (PL). Severity of depression was measured using the 21-item Hamilton depression rating scale (HRS) and a second linear rating scale (LRS) of severity of depressive symptoms that omitted anxiety symptoms. There was a significant correlation between the ratio of erythrocyte PL arachidonic acid (AA) to eicosapentaenoic acid (EPA) and severity of depression as rated by the HRS (P < 0.05) and the LRS for depression (P < 0.01). There was also a significant negative correlation between erythrocyte EPA and the LRS (P < 0.05). The AA/EPA ratio in plasma PL and the ratio of erythrocyte long-chain (C20 and C22 carbon) n-6 to long-chain n-3 PUFA were also significantly correlated with the LRS (P < 0.05). These findings do not appear to be simply explained by differences in dietary intake of EPA. We cannot determine whether the high ratios of AA/EPA in both plasma and erythrocyte PL are the result of depression or whether tissue PUFA change predate the depressive symptoms. We suggest, however, that our findings provide a basis for studying the effect of the nutritional supplementation of depressed subjects, aimed at reducing the AA/EPA ratio in tissues and severity of depression.


Asunto(s)
Ácido Araquidónico/sangre , Depresión/sangre , Trastorno Depresivo/sangre , Ácido Eicosapentaenoico/sangre , Adulto , Anciano , Eritrocitos/metabolismo , Ácidos Grasos Omega-3/sangre , Ácidos Grasos Omega-6 , Ácidos Grasos Insaturados/sangre , Femenino , Humanos , Masculino , Persona de Mediana Edad , Fosfolípidos/sangre
10.
13.
Plant Physiol ; 45(4): 495-9, 1970 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-5427119

RESUMEN

Sodium pyruvate and dinitrophenol stimulated O(2) uptake of freshly cut phloem parenchyma from carrot roots by 63 and 120% at optimal concentrations, indicating that production of pyruvate by glycolysis regulates over-all respiratory rate. Adding 0.5 to 6.7 mm Na(3)ADP and Na(3)ATP to slices rapidly stimulates respiration rate by 20 to 85%. The effect is greater at the lower end of this concentration range and is not due to change in pH or active cation uptake. It is suggested that treating tissue with both nucleotides stimulates pyruvate kinase, the rate-limiting step in respiration of freshly cut slices, by increasing the concentration of endogenous ADP. Adenosine diphosphate continued to stimulate O(2) uptake until the peak of induced respiration, but ATP inhibited respiration during development and decline of this peak. Absence of respiratory stimulation by NaH(2)PO(4) and of respiratory inhibition by added nucleosides confirms that inorganic phosphate is not a limiting factor of respiration in freshly cut slices. The stimulation of respiration rate of these slices by dinitrophenol is consistent with results from experiments in which ADP and ATP were applied to the tissue.


Asunto(s)
Nucleótidos de Adenina/farmacología , Adenosina Trifosfato/farmacología , Consumo de Oxígeno/efectos de los fármacos , Plantas Comestibles/metabolismo , Dinitrofenoles/farmacología , Piruvato Quinasa/metabolismo , Piruvatos/farmacología , Estimulación Química
14.
Plant Physiol ; 45(4): 500-3, 1970 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-5427120

RESUMEN

Incubation of freshly cut carrot tissue in Na(3)ADP and Na(3)ATP promotes a marked intracellular increase in both ADP and ATP. The rapid increase in ATP during an ADP incubation and in ADP during an ATP incubation results from the activity of cytoplasmic enzyme systems upon the nucleotide absorbed into the cell from the incubation medium. There is a crossover at the pyruvate kinase reaction, but not at phosphofructokinase, when either ADP or ATP is added to freshly cut tissue. In tissue slices washed in distilled water, pyruvate kinase exhibits a negative crossover in the first 2 hours and a positive crossover between 2 and 10 hours after cutting. Cutting induces large changes in levels of nucleotides and glycolytic intermediates. There is an immediate depletion of these compounds upon cutting, so that nucleotides are added to a system where respiration rate is limited by endogenous nucleotide level. Variation in respiratory values for fresh cut tissue can be explained in terms of a range of endogenous ADP levels in different tissue batches. Nucleotide incubation experiments are discussed in relation to the provision of ADP to rate-limiting pyruvate kinase during the first phase in development of the induced respiration.


Asunto(s)
Nucleótidos de Adenina/farmacología , Adenosina Trifosfato/farmacología , Glucólisis/efectos de los fármacos , Hexosafosfatos/metabolismo , Plantas Comestibles/metabolismo , Piruvatos/metabolismo , Consumo de Oxígeno , Fosfatos/metabolismo , Piruvato Quinasa/metabolismo
15.
Immunology ; 28(2): 253-69, 1975 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-1079016

RESUMEN

Purified T lymphocytes from normal mouse spleen restored the antibody-forming cell response to sheep erythrocytes of various B lymphocyte populations when separated from them by a cell-impermeable dialysis or nucleopore membrane. A 2-5-fold increase occurred when spleen cells from neonatally thymectomized mice or congenitally athymic mice, and an adherent spleen cell population were used as sources of B cells. Antigen was required in both T- and B-cell compartments, but a nonspecific reconstitution occurred when the antigens present in the two compartments were different. It is concluded that during the first 20 hours of culture, T lymphocytes produce a non-specific factor in response to antigen. Although the factor acts at a distance, it does not have a non-specific mitogenic effect upon all B lymphocytes. Some of its properties are similar to those of other reported T-cell factors and of the 'sheep erythrocyte reconstitution factor', found naturally in some batches of foetal calf serum.


Asunto(s)
Formación de Anticuerpos , Linfocitos B/inmunología , Eritrocitos/inmunología , Linfocitos T/inmunología , Animales , Animales Recién Nacidos , Especificidad de Anticuerpos , Células Productoras de Anticuerpos/inmunología , Linfocitos B/metabolismo , Células Cultivadas , Medios de Cultivo , Diálisis , Membranas Artificiales , Ratones/inmunología , Ratones Endogámicos CBA , Ratones Desnudos , Ovinos/inmunología , Bazo/citología , Linfocitos T/metabolismo , Timectomía , Timidina/metabolismo , Timo/anomalías , Timo/fisiología
16.
Appl Opt ; 7(5): 845-8, 1968 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-20068696

RESUMEN

Chemical durability, or corrosion resistance, of optical glasses is a special problem; the chemical composition of many such glasses makes them quite vulnerable. Service problems frequently encountered include those involving weathering by atmospheric moisture and leaching during processing, e.g., polishing, or handling. The mechanisms of weathering can usefully by classified as alkaline attack, or etching, and as acid attack, or leaching. Various test methods are available; these are of varying utility.

17.
Plant Physiol ; 50(6): 682-6, 1972 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-16658243

RESUMEN

In slices of carrot-phloem parenchyma washed for 7 days in water at 20 C, 50 mm KCl stimulates respiration by up to 100% of the ground respiration within 4 minutes of application. The data presented imply that ADP liberated in the cytoplasm as a consequence of KCl accumulation first stimulates a regulator reaction requiring ADP (phosphoglycerate kinase). Thereafter, the point of control alternates between this reaction and the phosphofructokinase reaction, forming a sequence of enzyme stimulations which continue after the new steady state of increased respiration is established. KCl induces a similar sequence in slices washed for 3 days, but it is completed within 3 minutes, and metabolite oscillations are not so marked. In slices washed for 2 days, KCl stimulates respiration by less than 10%, and the sequence of regulator reactions does not occur. Phosphoglycerate kinase is the only enzyme stimulated within 3 minutes of applying KCl to these slices. Contrary to previous reports, KCl frequently stimulates the respiration of freshly prepared slices by 10 to 30%.

18.
Plant Physiol ; 45(4): 490-4, 1970 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-4246656

RESUMEN

Changes in respiration in aging carrot slices are correlated with a characteristic sequence of activation of the irreversible reactions of the glycolytic pathway. The induced "wound" respiration increases in two stages; these appear to correspond to a period of active synthesis, when ADP, produced in the cytoplasm from synthetic reactions, activates pyruvate kinase, and a period of readjustment when ATP, no longer reacting in synthetic reactions, activates phosphofructokinase. Although ATP is cited frequently as a negative effector of phosphofructokinase, unless the concentration of ATP at the site of phosphofructokinase is 50-fold higher than the concentration expressed per unit fresh weight of the tissue, it cannot act in this way in carrot slices. The activation of the oxidative pentose phosphate pathway observed by ap Rees and Beevers is restricted to the first stage of the induced respiration.


Asunto(s)
Glucólisis , Consumo de Oxígeno , Plantas Comestibles/metabolismo , Nucleótidos de Adenina/metabolismo , Envejecimiento , Pentosafosfatos/metabolismo , Fosfofructoquinasa-1/metabolismo , Piruvato Quinasa/metabolismo , Piruvatos/metabolismo
19.
Can J Microbiol ; 25(9): 1021-6, 1979 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-44222

RESUMEN

Macroconidia of Sporidesmium sclerotivorum, a mycoparasite of Sclerotinia spp., germinated after 3 days in soil adjacent to sclerotia of S. minor and on membrane filters placed on soil containing sclerotia. Germination increased with time up to 18 days and with concentration of sclerotia. Conidia as distant as 9 mm from single sclerotia germinated. Germination of conidia was maximum on a sclerotial agar medium in the range of pH 5 to pH 7. Cultivation of S. sclerotivorum parasitically on living sclerotia proceeded optimally in moist, fine quartz sand amended with 1 to 2% (w/w) sclerotia and 0.07% (w/w) CaCO3, at 25 degrees C. Infection of sclerotia in sand reached 100% by 5 weeks. Conidia production paralled infection resulting in logarithmic increase in numbers; a maximum of 3 x 10(5) to 4 x 10(5) conidia/g was reached in 6 to 12 weeks. Viability of air-dried sand-sclerotial cultures of S. sclerotivorum was reduced after 1 and 6 days, but viability was undiminished in air-dried soil. Sporidesmium sclerotivorum survived in moist and air-dried soils stored at room temperature for 15 months.


Asunto(s)
Antibiosis , Ascomicetos/crecimiento & desarrollo , Hongos Mitospóricos/crecimiento & desarrollo , Microbiología del Suelo , Carbonato de Calcio/farmacología , Concentración de Iones de Hidrógeno , Hongos Mitospóricos/efectos de los fármacos , Esporas Fúngicas/efectos de los fármacos , Esporas Fúngicas/crecimiento & desarrollo , Temperatura
20.
Can J Microbiol ; 27(9): 886-92, 1981 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-7198002

RESUMEN

Sclerotia of Sclerotinia minor were parasitized by Teratosperma oligocladum, a recently described dematiaceous hyphomycete. The mycoparasite was cultured on living sclerotia placed on water agar and on sclerotia in moist sand. It grew poorly on several common laboratory media but growth in vitro was enhanced by supplements of soil extract and, especially, by aqueous extracts of sclerotia. Sclerotia of S. minor, S. sclerotiorum, S. trifoliorum, Sclerotium cepivorum, and Botrytis cinerea were parasitized in vitro, but sclerotia of Sclerotium rolfsii and Macrophomina phaseolina were not. Macroconidia of T. oligocladum germinated on membrane filters placed on soil containing sclerotia of S. minor but not on soil without sclerotia. Sclerotia of three Sclerotinia spp. were infected within 2 weeks in soil infested with the mycoparasite. Teratosperma oligocladum parasitized and destroyed all of the sclerotia of S. minor buried in a natural soil by 10 weeks. Parasitism was equally good at 20 and 25 degrees C, but occurred more slowly at 15 degrees C. No parasitic activity occurred at 30 degrees C. The morphology, cultural characteristics, and mycoparasitic habit of T. oligocladum indicated that it was similar in many respects to the mycoparasite, Sporidesmium sclerotivorum, and that it is a potentially useful agent fo the biological control for sclerotial plant pathogens.


Asunto(s)
Ascomicetos/crecimiento & desarrollo , Hongos Mitospóricos/crecimiento & desarrollo , Microbiología del Suelo , Medios de Cultivo , Ecología , Hongos Mitospóricos/aislamiento & purificación , Temperatura
SELECCIÓN DE REFERENCIAS
Detalles de la búsqueda