RESUMO
The reaction of the rice mutant HEBIBA differs from that of wild-type rice in that the mutant responds inversely to red light and is defective in the light-triggered biosynthesis of jasmonic acid (JA). Using the wild type and the HEBIBA mutant of rice in a differential display screen, we attempted to identify genes that act in or near the convergence point of light and JA signalling. We isolated specifically regulated DNA fragments from approximately 10 000 displayed bands, and identified a new early light- and JA-induced gene. This gene encodes an enzyme containing a GDSL motif, showing 38 % identity at the amino acid level to lipase Arab-1 in Arabidopsis thaliana. The GDSL CONTAINING ENZYME RICE 1 gene (GER1) is rapidly induced by both red (R) and far-red (FR) light and by JA. The results are discussed with respect to a possible role for GER1 as a negative regulator of coleoptile elongation in the context of recent findings on the impact of JA on light signalling.
Assuntos
Motivos de Aminoácidos , Ciclopentanos/farmacologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Luz , Oryza/genética , Proteínas de Plantas/genética , Clonagem Molecular , Proteínas de Fluorescência Verde/análise , Dados de Sequência Molecular , Oryza/efeitos dos fármacos , Oryza/efeitos da radiação , Oxilipinas , Fitocromo A/fisiologia , Fitocromo B/fisiologia , Proteínas de Plantas/análise , Proteínas de Plantas/química , Alinhamento de Sequência , Transdução de SinaisRESUMO
To find components which participate in gravitropic signal transmission, we screened different cell biological inhibitors for their effect on gravitropic bending of rice coleoptiles. Acrylamide, which is known to affect intermediate filaments in mammalian cells, strongly inhibited gravitropic bending at concentrations that did not inhibit growth of coleoptile segments. This inhibition was reversible. Investigating the acrylamide effect further, we found that it interferes with an event that occurs around 15 min after the onset of stimulation. We also observed that acrylamide inhibits polar indolyl-3-acetic acid transport. Furthermore, acrylamide efficiently eliminated microtubules, whereas actin filaments remained intact. To our knowledge this is the first report of effects of monoacrylamide in plant cells.
Assuntos
Acrilamida/farmacologia , Cotilédone/efeitos dos fármacos , Gravitropismo/efeitos dos fármacos , Microtúbulos/efeitos dos fármacos , Oryza/efeitos dos fármacos , Citoesqueleto de Actina/metabolismo , Transporte Biológico , Relação Dose-Resposta a Droga , Ácidos Indolacéticos/metabolismo , Oryza/citologia , Epiderme Vegetal/citologia , Epiderme Vegetal/efeitos dos fármacos , Fatores de TempoRESUMO
We developed a high-throughput technique for the generation of cDNA libraries in the yeast Saccharomyces cerevisiae which enables the selection of cloned cDNA inserts containing open reading frames (ORFs). For direct screening of random-primed cDNA libraries, we have constructed a yeast shuttle/expression vector, the so-called ORF vector pYEXTSH3, which allows the enriched growth of protein expression clones. The selection system is based on the HIS3 marker gene fused to the C terminus of the cDNA insert. The cDNAs cloned in-frame result in histidine prototrophic yeast cells growing on minimal medium, whereas clones bearing the vector without insert or out-of-frame inserts should not grow on this medium. A randomly primed cDNA library from human fetal brain tissue was cloned in this novel vector, and using robot technology the selected clones were arrayed in microtiter plates and were analyzed by sequencing and for protein expression. In the constructed cDNA expression library, about 60% of clones bear an insert in the correct reading frame. In comparison to unselected libraries it was possible to increase the clones with inserts in the correct reading frame more than fourfold, from 14% to 60%. With the expression system described here, we could avoid time-consuming and costly techniques for identification of clones expressing protein by using antibody screening on high-density filters and subsequently rearraying the selected clones in a new "daughter" library. The advantage of this ORF vector is that, in a one-step screening procedure, it allows the generation of expression libraries enriched for clones with correct reading frames as sources of recombinant proteins.
Assuntos
DNA Complementar/biossíntese , Biblioteca Gênica , Fases de Leitura Aberta/genética , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Saccharomyces cerevisiae/genética , Anticorpos Monoclonais/análise , Química Encefálica/genética , Química Encefálica/imunologia , Feto , Humanos , Fases de Leitura Aberta/imunologia , Plasmídeos , Proteínas Recombinantes/imunologiaRESUMO
Methadone disposition was studied in three patients receiving chronic methadone treatment and having chronic renal disease: one oliguric patient during peritoneal dialysis, one anuric patient on hemodialysis, and one patient following renal transplantation. In all three patients plasma levels of methadone remained within the desired therapeutic range (0.09--0.68 microgram/ml) for the doses received (40-50 mg/day). Elimination of methadone and its metabolites was almost exclusively by the fecal route in the anuric patient. Less than 1% of the daily dose was removed by peritoneal dialysis or hemodialysis. There was no laboratory or clinical evidence for accumulation of either methadone or its metabolites, suggesting that methadone is an appropriate narcotic to use in patients with renal disease.
Assuntos
Dependência de Heroína/reabilitação , Falência Renal Crônica , Metadona/uso terapêutico , Adulto , Humanos , Falência Renal Crônica/terapia , Transplante de Rim , Masculino , Metadona/efeitos adversos , Metadona/sangue , Diálise Peritoneal , Diálise RenalRESUMO
Cerebral spinal fluid (CSF) levels of methadone were measured in nine methadone maintenance patients requiring lumbar punctures for medical or surgical treatment. Concurrent serum methadone levels were also determined. The CSF concentration of methadone in all cases was a fraction of the corresponding serum level--ranging from 2 to 73%. The CSF concentrations of methadone ranged from 0.010 to 0.097 ng%. Peak methadone levels in CSF appeared approximately 3 - 8 hours after methadone administration.
Assuntos
Metadona/líquido cefalorraquidiano , Humanos , Metadona/sangue , Fatores de TempoAssuntos
Metadona , Rifampina/efeitos adversos , Síndrome de Abstinência a Substâncias/induzido quimicamente , Adulto , Idoso , Interações Medicamentosas , Dependência de Heroína/reabilitação , Humanos , Isoniazida/uso terapêutico , Masculino , Metadona/metabolismo , Metadona/uso terapêutico , Pessoa de Meia-Idade , Rifampina/uso terapêutico , Tuberculose Pulmonar/tratamento farmacológicoAssuntos
Metadona/farmacologia , Adulto , Idoso , Cromatografia Gasosa , Interações Medicamentosas , Fezes/análise , Feminino , Dependência de Heroína/complicações , Dependência de Heroína/reabilitação , Humanos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Espectrometria de Massas , Metadona/análise , Metadona/metabolismo , Metadona/uso terapêutico , Métodos , Pessoa de Meia-Idade , Naloxona/farmacologia , Naloxona/uso terapêutico , Rifampina/farmacologia , Rifampina/uso terapêutico , Síndrome de Abstinência a Substâncias/induzido quimicamente , Tuberculose Pulmonar/complicações , Tuberculose Pulmonar/tratamento farmacológicoRESUMO
Assessment of nutritional status of patients with cystic fibrosis of the pancreas (CFP) showed that poor growth was associated with low concentrations of albumin, urea nitrogen, and cholesterol in serum and with elevated white blood cell (WBC) counts. Patients with CFP maintained weight approximately 1 standard deviation below the mean until 8 years, after which there was a progressive decline in growth rate compared to normal. A complete dietary supplement consisting of a beef serum hydrolysate, a glucose polymer, and medium-chain triglycerides was given to 15 patients for a year. Patients who received the diet showed significant gains in weight, significant increase in clinical score, significant increase in serum albumin level, and a significant drop in the WBC count compared to control patients who did not receive the supplement.