RESUMEN
Amino acid residues 57-69 in alphaB-crystallin have been implicated as a target protein binding site. Moreover, a direct correlation between the extent of alpha-crystallin hydrophobicity and chaperone-like activity has been demonstrated. The purpose of this study was to mutate a moderately hydrophobic residue Met-68 (M-68) in the above region to strongly hydrophobic and hydrophilic residues and show whether chaperoning ability is affected with or without structural changes. Mutation of M-68 to Val, Ile or Thr did not result in significant changes in molecular mass and secondary and tertiary structures. However, the Val and Ile mutants showed significant improvement and the Thr mutant showed substantial loss in chaperone activity. Differences in chaperone function in the absence of any structural changes confirmed that the hydrophobicity or hydrophilicity of the substituted amino acid in the putative target protein binding site was the only contributing factor.
Asunto(s)
Cristalinas/química , Cristalinas/genética , Metionina/química , Animales , Sitios de Unión , Western Blotting , Dicroismo Circular , Clonación Molecular , Electroforesis en Gel de Poliacrilamida , Isoleucina/química , Mutagénesis Sitio-Dirigida , Mutación , Naftalenosulfonatos/farmacología , Unión Proteica , Estructura Secundaria de Proteína , Estructura Terciaria de Proteína , Ratas , Proteínas Recombinantes/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Temperatura , Treonina/química , Factores de Tiempo , Valina/químicaRESUMEN
An autosomal dominant congenital cataract in human is associated with mutation of Arg-116 to Cys (R116C) in alpha A-crystallin. To investigate the molecular basis of cataract formation, rat alpha A-crystallin cDNA was cloned into pET-23d(+), and the site-directed mutants S142C (similar to wild-type human alpha A) and R116C/S142C or R116C (similar to human R116C variant) were generated. These were expressed in E. coli and the recombinant alpha A-crystallins purified by Sephacryl size-exclusion chromatography. The chaperone-like function of mutant R116C determined at 37 degrees C with insulin and alcohol dehydrogenase as target proteins was about 40% lower than those of wild-type and mutant S142C. Based on size-exclusion chromatography data, the oligomeric size of the R116C mutant was about 2000 kDa at 25 degrees C, 1400 kDa at 37 degrees C, and 900 kDa at 45 degrees C. In comparison, alpha A-wild-type and alpha A-S142C ranged from 477 to 581 kDa. Heat stability studies corroborated the effect of temperature on the dynamic quaternary structure of the R116C mutant. Circular dichroism spectra showed secondary and tertiary structural changes, and ANS fluorescence spectra showed loss of surface hydrophobicity in the R116C mutant. These findings suggest that the molecular basis for the congenital cataract with the alpha A-R116C mutation is due to the generation of a highly oligomerized alpha A-crystallin having a modified structure and decreased chaperone-like function.
Asunto(s)
Arginina/genética , Biopolímeros/química , Biopolímeros/genética , Cristalinas/química , Cristalinas/genética , Chaperonas Moleculares/genética , Animales , Biopolímeros/biosíntesis , Biopolímeros/fisiología , Cromatografía en Gel , Clonación Molecular , Cristalinas/fisiología , Cisteína/genética , Calor , Chaperonas Moleculares/química , Chaperonas Moleculares/fisiología , Peso Molecular , Mutagénesis Sitio-Dirigida , Conformación Proteica , Estructura Secundaria de Proteína , Estructura Terciaria de Proteína , Ratas , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/química , Proteínas Recombinantes/aislamiento & purificación , Serina/genética , Espectrometría de FluorescenciaRESUMEN
A multicenter double-blind study was conducted in 416 patients (306 male, 110 female) with active endoscopically proven duodenal ulcers who were randomly allocated to receive the prostaglandin E1 methyl ester analog (Misoprostol/Cytotec), either in a dose of 400 micrograms twice daily (206 patients) or 200 micrograms four times daily (210 patients). No significant difference in the healing rates between the two groups was observed at four or eight weeks. In patients treated twice daily, the ulcer healing rate at four weeks for the intent-to-treat cohort was 124/205 (60.5%) and for the evaluable cohort was 96/136 (69.1%). In patients treated four times daily, the healing rate was 124/207 (59.9%) for the intent-to-treat cohort and 96/148 (64.9%) for the evaluable cohort. Similarly, the healing rates achieved at eight weeks for the twice- and the four-times-daily dosages in the intent-to-treat cohort were 72.2% and 74.4%, respectively, and for the evaluable cohort were 88.0% and 86.6%, respectively. Significantly more patients receiving misoprostol twice daily were free of ulcer pain after four weeks of treatment than were those receiving misoprostol four times daily, namely, 71.4% as compared with 57.9%, respectively (P = 0.003) and for a median period of 21 as compared with 17 days (P = 0.002). Diarrhea was more common in patients receiving the drug twice daily, (15.5%) than in those treated four times daily (5%) (P = 0.001). Diarrhea, three or more stools daily, was often transient and self-limiting and only necessitated withdrawal from the trial in nine (4.4%) of those treated with misoprostol twice daily and in one patient (0.5%) of those treated four times daily.(ABSTRACT TRUNCATED AT 250 WORDS)
Asunto(s)
Alprostadil/análogos & derivados , Antiulcerosos/administración & dosificación , Úlcera Duodenal/tratamiento farmacológico , Alprostadil/administración & dosificación , Alprostadil/efectos adversos , Alprostadil/uso terapéutico , Antiulcerosos/uso terapéutico , Ensayos Clínicos como Asunto , Método Doble Ciego , Esquema de Medicación , Femenino , Gastroscopía , Humanos , Masculino , Persona de Mediana Edad , Misoprostol , Distribución Aleatoria , Cicatrización de HeridasRESUMEN
Femulen, a progestogen only oral contraceptive (ethynodiol diacetate 0.5mg), was evaluated for its contraceptive efficacy and safety in 425 women aged between 16 and 47 years. This was a multicentre open study carried out in General Practice and Family Planning clinics. Five pregnancies were reported, three of which were a result of patient failure. The net pregnancy rate at one year for method failure was 0.5%. No ectopic pregnancy was reported. The median length of the menstrual period was between four and five days and the average length of the non-bleeding interval remained between 24 and 25 days throughout the study. Blood pressure on the whole remained within normal limits. However, there was a small decrease in both systolic and diastolic blood pressure which did not reach significant levels. Body weight was unaltered and no abnormality was found in cervical smears. Femulen was shown to be an effective and acceptable contraceptive in women of varying ages.
PIP: Femulen, a progestogen only oral contraceptive (ethynodiol diacetate 0.5mg), was evaluated for its contraceptive efficacy and safety in 425 women aged between 16 and 47 years. This was a multicenter open study carried out in General Practice and Family Planning clinics. 5 pregnancies were reported, 3 of which were a result of patient failure. The net pregnancy rate at 1 year for method failure was 0.5%. No ectopic pregnancy was reported. The median length of the menstrual period was between 4 and 5 days and the average length of the non-bleeding interval remained between 24 and 25 days throughout the study. Blood pressure on the whole remained within normal limits. However, there was a small increase in both systolic and diastolic blood pressure which did not reach significant levels. Body weight was unaltered and no abnormality was found in cervical smears. Femulen was shown to be an effective and acceptable contraceptive in women of varying ages.
Asunto(s)
Diacetato de Etinodiol/administración & dosificación , Adolescente , Adulto , Presión Sanguínea/efectos de los fármacos , Ensayos Clínicos como Asunto , Diacetato de Etinodiol/efectos adversos , Femenino , Humanos , Menstruación/efectos de los fármacos , Persona de Mediana Edad , Dolor/etiología , Pacientes Desistentes del Tratamiento , EmbarazoRESUMEN
The effect of spironolactone in the alleviation of the symptoms of the premenstrual syndrome was compared with placebo in a double-blind, parallel group controlled study. One tablet daily of 100 mg spironolactone or placebo was given to 63 women from Day 12 of the menstrual cycle until the first day of the next menstrual bleed. This regimen was repeated for two consecutive cycles. Spironolactone was statistically significantly superior in providing relief from bloatedness (p less than 0.001). No statistically significant changes were observed in blood biochemistry of plasma hormone levels of oestradiol, progesterone or prolactin, though an increase in serum aldosterone levels was seen in the spironolactone-treated group. No differences were detected in weight, blood pressure or the incidence and severity of complaints following treatment.
Asunto(s)
Síndrome Premenstrual/tratamiento farmacológico , Espironolactona/uso terapéutico , Adulto , Aldosterona/sangre , Método Doble Ciego , Evaluación de Medicamentos , Femenino , Humanos , Persona de Mediana Edad , Pacientes Desistentes del Tratamiento , Síndrome Premenstrual/sangre , Síndrome Premenstrual/fisiopatología , Distribución AleatoriaRESUMEN
Twelve women with established lactation of 4-8 weeks duration were given a low-dose progestogen-only contraceptive, ethynodiol diacetate 0.5 mg (Femulen) daily. On the seventh and eight day of the study, prior to the mother's taking the pill, a blood sample was taken from her and from the infant. Further blood samples were collected from the mother 4 and 12 hours later. Breast milk samples were collected at every feed on day 7 and day 8. Ethynodiol diacetate is rapidly metabolised in humans, changing into the metabolite norethisterone which is found in both blood and milk. Hence, norethisterone concentrations were estimated. On day 7 and day 8, four hours after ingestion of the pill, the median norethisterone maternal plasma concentration was 1.60 ng/ml and it fell to a median level of 0.30 ng/ml prior to the next dose of the pill. At this time the median infant concentration was 0.10 ng/ml but the maximum observed level was 0.50 ng/ml. In the breast milk the norethisterone concentration appears to peak at around 4-8 hours following the ingestion of the pill. The maximum observed concentration in breast milk was 0.84 ng/ml. The amount of norethisterone ingested by the infant averaged 0.02% (6.65 micrograms) of the dose of ethynodiol diacetate ingested by the mother. The maximum observed on any one day was 0.07% (27.52 micrograms). The above results indicate that the amount of progestogen ingested by the infant from its mother's milk is small and is unlikely to pose a risk to the infant.
Asunto(s)
Anticonceptivos Sintéticos Orales/administración & dosificación , Diacetato de Etinodiol/administración & dosificación , Leche Humana/metabolismo , Noretindrona/metabolismo , Biotransformación , Anticonceptivos Sintéticos Orales/efectos adversos , Anticonceptivos Sintéticos Orales/metabolismo , Diacetato de Etinodiol/efectos adversos , Diacetato de Etinodiol/metabolismo , Femenino , Humanos , Recién Nacido , Cinética , Noretindrona/sangre , EmbarazoRESUMEN
A simple, convenient, and accurate method of detecting and measuring even the smallest degree of cyclodeviation with the help of two special major amblyoscope slides is described. Routine use of these slides in the investigation of all paralytic squints to detect and measure cyclodeviation is suggested. This will prove useful in the correct diagnosis and in the adequate management of a case of cyclovertical muscle palsy.