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1.
Clin Exp Obstet Gynecol ; 43(1): 31-6, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27048014

RESUMO

PURPOSE OF THE INVESTIGATION: To verify whether histologic confirmation of endometriosis impacts fertility outcomes. MATERIALS AND METHODS: Women with unexplained infertility (UI) underwent laparoscopic excision or ablation with CO2 laser or electrocautery of all suspected endometriotic lesions, followed by clinical treatment between January 2007 and December 2013; pregnancy (> 12 weeks) within 12 months of monitored cycles was the main outcome measured. RESULTS: Women with histological confirmation (n = 74) did not differ from those not confirmed (n = 29) with age, body mass index, gravidity, parity, ovulation induction protocol, and past duration of infertility. Pregnancy outcome was similar in both groups (39/74 vs. 15/29-p = 0.9--Chi-square) and there was no statistical difference in time to conceive/deliver (p = 0.7) between groups. CONCLUSIONS: There is no difference in fertility outcomes in women with UI, whether or not suspected endometriosis is confirmed pathologically.


Assuntos
Endometriose/cirurgia , Procedimentos Cirúrgicos em Ginecologia/métodos , Infertilidade Feminina/cirurgia , Laparoscopia/métodos , Complicações na Gravidez/cirurgia , Adulto , Endometriose/complicações , Endometriose/diagnóstico , Feminino , Fertilidade , Humanos , Infertilidade Feminina/etiologia , Gravidez , Resultado da Gravidez , Adulto Jovem
2.
J Med Ethics ; 33(8): 487-90, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17664311

RESUMO

Earlier in the pages of this journal (p 481), Wendler and Miller offered the "net risks test" as an alternative approach to the ethical analysis of benefits and harms in research. They have been vocal critics of the dominant view of benefit-harm analysis in research ethics, which encompasses core concepts of duty of care, clinical equipoise and component analysis. They had been challenged to come up with a viable alternative to component analysis which meets five criteria. The alternative must (1) protect research subjects; (2) allow clinical research to proceed; (3) explain how physicians may offer trial enrolment to their patients; (4) address the challenges posed by research containing a mixture of interventions and (5) define ethical standards according to which the risks and potential benefits of research may be consistently evaluated. This response argues that the net risks test meets none of these criteria and concludes that it is not a viable alternative to component analysis.


Assuntos
Pesquisa Biomédica/ética , Ensaios Clínicos como Assunto/ética , Comitês de Ética em Pesquisa , Experimentação Humana não Terapêutica/ética , Sujeitos da Pesquisa , Ensaios Clínicos como Assunto/efeitos adversos , Humanos , Medição de Risco
3.
J Med Ethics ; 32(9): 542-7, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16943338

RESUMO

When may a physician enroll a patient in clinical research? An adequate answer to this question requires clarification of trust-based obligations of the state and the physician-researcher respectively to the patient-subject. The state relies on the voluntarism of patient-subjects to advance the public interest in science. Accordingly, it is obligated to protect the agent-neutral interests of patient-subjects through promulgating standards that secure these interests. Component analysis is the only comprehensive and systematic specification of regulatory standards for benefit-harm evaluation by research ethics committees (RECs). Clinical equipoise, a standard in component analysis, ensures the treatment arms of a randomised control trial are consistent with competent medical care. It thus serves to protect agent-neutral welfare interests of the patient-subject. But REC review occurs prior to enrolment, highlighting the independent responsibility of the physician-researcher to protect the agent-relative welfare interests of the patient-subject. In a novel interpretation of the duty of care, we argue for a "clinical judgment principle" which requires the physician-researcher to exercise judgment in the interests of the patient-subject taking into account evidence on treatments and the patient-subject's circumstances.


Assuntos
Ética em Pesquisa , Obrigações Morais , Seleção de Pacientes/ética , Confiança , Beneficência , Comitês de Ética em Pesquisa , Regulamentação Governamental , Humanos , Julgamento , Defesa do Paciente/ética , Ensaios Clínicos Controlados Aleatórios como Assunto/ética , Ensaios Clínicos Controlados Aleatórios como Assunto/normas , Pesquisadores/ética , Relações Pesquisador-Sujeito
4.
Pharmacogenomics J ; 4(1): 9-16, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-14647406

RESUMO

The existing EELS literature has usefully identified the scope of ethical issues posed by pharmacogenetic and pharmacogenomic research. The time has come for in-depth examination of particular ethical issues. The involvement of racial and ethnic communities in pharmacogenetic and pharmacogenomic research is contentious precisely because it touches upon the science and politics of studying racial and ethnic difference. To date, the ethics literature has not seriously taken account of the fact that such research impinges upon the interests of communities, and that taking such interests seriously requires that we both protect and empower communities in research. We propose a framework that rests upon the recognition that communities are heterogeneous human associations and differing policies are appropriate for differing communities. Community consent and consultation and community consultation alone are neither appropriate nor required for all pharmacogenetic and pharmacogenomic research. Rather, application of these policy protections must take into account particulars of both planned research and the communities involved.


Assuntos
Consentimento Livre e Esclarecido/ética , Farmacogenética/ética , Características de Residência , Humanos , Consentimento Livre e Esclarecido/legislação & jurisprudência , Farmacogenética/economia , Farmacogenética/legislação & jurisprudência , Farmacogenética/métodos
5.
Arch Gynecol Obstet ; 270(4): 230-4, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14648073

RESUMO

INTRODUCTION: This study was designed to assess changes in biochemical markers of bone remodeling in early postmenopausal women receiving calcium supplementation. MATERIALS AND METHODS: In a randomized cross-over study of eighteen weeks duration, the effect of a 6-week calcium supplementation (1000 mg calcium carbonate) on biochemical markers of bone resorption (collagen type I cross-linked C- and N-telopeptides) and bone formation (osteocalcin, total and bone-specific alkaline phosphatase), and total serum calcium was assessed in 27 early postmenopausal women. RESULTS: While total serum calcium levels increased significantly due to calcium supplementation (p<0.05), biochemical markers of both bone resorption and formation remained virtually unchanged. CONCLUSION: In contrast to other investigations, there was no significant short-term effect of calcium supplementation on biochemical markers of either bone resorption or formation.


Assuntos
Biomarcadores/metabolismo , Remodelação Óssea/efeitos dos fármacos , Cálcio/administração & dosagem , Suplementos Nutricionais , Pós-Menopausa/fisiologia , Cálcio/farmacologia , Estudos Cross-Over , Esquema de Medicação , Feminino , Humanos , Pessoa de Meia-Idade , Pós-Menopausa/metabolismo
6.
Arch Gynecol Obstet ; 268(4): 309-16, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-14504876

RESUMO

INTRODUCTION: The effect of pregnancy upon the maternal skeleton is not fully understood. The information that has been gathered by recent studies is conflicting with regard to overall loss or gain of bone during pregnancy. The aim of the present longitudinal, controlled study, therefore, was to investigate the effect of pregnancy on lumbar spine, wrist, and hip bone mineral density, and to describe bone remodeling during pregnancy as indicated by biochemical markers of both bone resorption and formation. MATERIALS AND METHODS: Thirty healthy women (15 subjects seeking pregnancy and 15 non-pregnant controls) were studied. Bone mineral density (BMD) was measured by dual-energy x-ray absorptiometry before conception and within 2 weeks after parturition. Markers of bone resorption (urinary cross-linked type I collagen N-telopeptides, serum type I collagen C-telopeptides) and bone formation (total and bone specific alkaline phosphatase, osteocalcin), and total serum calcium were analyzed before, during (once in each trimester), and after pregnancy. RESULTS: During pregnancy, BMD decreased significantly by 3.4+/-4.1% at the lumbar spine and 4.3+/-3.9% at the trochanter, while there was a slight but significant increase in BMD at the proximal 1/3 of the forearm (1.3+/-1.9%). Total hip and femoral neck BMD did not change significantly, nor did total and ultradistal forearm BMD. Bone resorption increased during pregnancy with peak levels in the third trimester (N-telopeptides) or post partum (C-telopeptides), respectively. The increase in bone resorption was accompanied by a significant decrease in serum calcium in the third trimester. Markers of bone formation showed a biphasic pattern with decreases from baseline to the first (total and bone specific alkaline phosphatase) or second trimester (osteocalcin), respectively, followed by a significant increase in the third trimester and post partum. There was no change in any parameter in the control group throughout the study. CONCLUSION: In conclusion, pregnancy is characterized by high bone turnover with resorption preceding formation. During the first and second trimester bone remodeling is uncoupled. Serum calcium decreases as bone resorption peaks in late pregnancy. There are significant decreases in bone mineral density at sites rich in trabecular bone, such as the lumbar spine and the trochanter.


Assuntos
Densidade Óssea/fisiologia , Remodelação Óssea/fisiologia , Adulto , Fosfatase Alcalina/sangue , Peso ao Nascer , Reabsorção Óssea , Cálcio/sangue , Colágeno Tipo I , Estradiol/sangue , Feminino , Fêmur , Colo do Fêmur , Idade Gestacional , Humanos , Vértebras Lombares , Osteocalcina/sangue , Fragmentos de Peptídeos/sangue , Peptídeos , Gravidez , Pró-Colágeno/sangue , Análise de Regressão , Aumento de Peso
8.
Biol Reprod ; 61(2): 553-6, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10411540

RESUMO

We previously described a modern, three-dimensional counting method for determining primordial follicle (PF) numbers in primate ovaries using a combination of fractionator and physical dissector techniques. The purposes of our current study were 1) to apply our method to describe intraindividual differences in PF numbers between ovaries and 2) perform a linear regression analysis of age versus mean PF number per ovary. Ovaries from 16 pigtailed monkeys (Macaca nemestrina) age 0.85-12.5 yr were examined. Both ovaries were available from 11 subjects. The difference between ovaries ranged from 2% to 22% (mean +/- SD, 10 +/- 7%) and was not statistically significant. Regression analysis of data from all 16 subjects displayed a log-linear relationship according to the equation log N(a) = 4.8542 - 0.0714(age) where N(a) is the number of PF at a given chronological age. The fit for this model was highly significant (r(2) = 0.73, p

Assuntos
Envelhecimento/fisiologia , Macaca nemestrina/fisiologia , Folículo Ovariano/crescimento & desenvolvimento , Ovário/crescimento & desenvolvimento , Animais , Feminino , Ovariectomia , Análise de Regressão
9.
J Reprod Med ; 43(5): 465-7, 1998 May.
Artigo em Inglês | MEDLINE | ID: mdl-9610474

RESUMO

BACKGROUND: Noncommunicating uterine horns are rare, occasionally presenting with functional endometrial cavities. Surgical removal of the noncommunicating horn is commonly performed to prevent endometriosis in these patients. CASE: A 41-year-old woman with a unicornuate uterus and noncommunicating uterine horn presented with a three-month history of right-sided pelvic pain. She had previously undergone multiple assisted reproductive technique attempts with superovulation and supraphysiologic serum estradiol levels and no apparent symptomatology or evidence of hematosalpinx during laparoscopy. Shortly after completing a donor oocyte recipient cycle, she developed acute right-sided pelvic pain. Diagnostic laparoscopy and subsequent laparotomy confirmed a right hematosalpinx and hematometra of the noncommunicating horn, with stage III endometriosis. CONCLUSION: Consideration of prophylactic resection of a noncommunicating uterine horn with a cavity should be considered in an asymptomatic, reproductive-age patient with this rare müllerian anomaly.


Assuntos
Doenças das Tubas Uterinas/diagnóstico , Hematometra/diagnóstico , Útero/anormalidades , Adulto , Transferência Embrionária , Doenças das Tubas Uterinas/patologia , Doenças das Tubas Uterinas/cirurgia , Feminino , Hematometra/patologia , Hematometra/cirurgia , Humanos , Doação de Oócitos , Dor Pélvica , Técnicas Reprodutivas , Útero/cirurgia
10.
Fertil Steril ; 68(3): 443-8, 1997 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9314912

RESUMO

OBJECTIVE: To compare day 3 FSH levels with biomarkers of aging in other organ systems in healthy, older, reproductive age women. DESIGN: Cross-sectional pilot study. SETTING: Healthy volunteers in an academic, tertiary care center. PATIENT(S): Healthy, regularly cycling women aged 40 to 45 years divided into two groups: those with normal day 3 FSH levels and those with elevated day 3 FSH levels. INTERVENTION(S): Blood and urine collection with blood pressure measurement, pulmonary function testing, bone densitometry, and skin biopsy. MAIN OUTCOME MEASURE(S): Comparison between groups for serum creatinine, albumin, glucose, hematocrit, DHEAS, fasting insulin, low-density lipoprotein cholesterol, and triglyceride levels; creatinine clearance (CrCl); forced expiratory volume in 1 second; forced vital capacity; bone density at the wrist, hip, and lumbar spine; and mean dermal thickness. RESULT(S): Hematocrit and CrCl values were significantly lower in the group with high FSH levels. Creatinine clearance also was significantly negatively correlated with FSH level. After Bonferroni adjustment for multiple testing, all measures were no longer different at the P < or = 0.05 level. CONCLUSION(S): Aging of the hypothalamic-pituitary-ovarian axis may parallel aging in other organ systems. Further longitudinal analyses are necessary to ascertain whether these measures will predict reproductive reserve before irreversible dysfunction occurs.


Assuntos
Envelhecimento/fisiologia , Hormônio Foliculoestimulante/sangue , Reprodução , Adulto , Biomarcadores , Creatinina/farmacocinética , Estudos Transversais , Feminino , Hematócrito , Humanos , Rim/fisiologia , Projetos Piloto
11.
Biol Reprod ; 56(4): 909-15, 1997 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9096872

RESUMO

Previous investigations of primordial follicle (PF) number in primate ovaries have used biased, model-based techniques that require correction factors based on assumptions regarding cell size, orientation, and shape. We sought to apply several techniques from the "new stereology" to obtain unbiased number estimates. This method involves a hierarchy of systematic random sampling combined with the physical disector and fractionator techniques. The method readily allows the estimation of the coefficient of error (CE) of each sampling level as it contributes to the observed variance of the overall number estimate. We examined one ovary from each of five pigtailed monkeys (Macaca nemestrina). The mean number of PF was 15,735 +/- 6214 (mean +/- SD). The mean CE for the individual number estimates was 0.085, contributing minimally to the inter-individual coefficient of variation (CV) of the primordial follicle numbers (CV = 0.395). The correlation between age and PF number was not significant (r = -0.74, p > 0.1). The total time taken to count the 100-200 PF necessary per ovary was 4-5 h. We conclude that this method produces reliable, unbiased estimates with measurable and acceptable accuracy in a robust, efficient manner.


Assuntos
Folículo Ovariano/citologia , Ovário/citologia , Envelhecimento , Análise de Variância , Animais , Dissecação/instrumentação , Dissecação/métodos , Feminino , Técnicas Histológicas , Macaca nemestrina , Variações Dependentes do Observador , Ovário/crescimento & desenvolvimento , Reprodutibilidade dos Testes , Maturidade Sexual
12.
J Clin Endocrinol Metab ; 81(5): 1946-51, 1996 May.
Artigo em Inglês | MEDLINE | ID: mdl-8626862

RESUMO

Reproductive aging in women (a physiological decline in the function of the hypothalamic-pituitary-ovarian axis) is an infrequently investigated and poorly understood biological phenomenon. Although menstrual irregularity and anovulation are known to precede the menopause, normal women in their fifth decade experience a profound decrease in fertility while still experiencing regular menstrual cycles. To further our understanding of the physiological changes associated with reproductive aging, this study examined the spontaneous development and function of ovarian follicles in normal women, aged 40-45 yr. The subjects were women (n = 21), aged 40-45 yr, who had regular 25- to 35-day ovulatory menstrual cycles, were not infertile, had no medical problems, and met specific criteria for weight, diet, and exercise. The controls were normal women (n = 20), age 20-25 yr, who met the same criteria. The subjects were monitored with daily hormone measurements [LH, FSH, estradiol (E), progesterone (P), and inhibin] and pelvic sonograms from day 1 of their study cycle until the dominant ovarian follicle reached a mean diameter of 15 mm and/or a serum E level of 550 pmol/L or higher was attained. At that time, 10,000 U hCG were given, and a transvaginal sonographic follicle aspiration was performed 32 h later. The follicular fluid (FF) was collected, stored frozen at -70 C, and later analyzed for E, P, testosterone (T), androstenedione, inhibin, insulin-like growth factor I (IGF-I), and IGF-II. The number of cycle days to aspiration was lower (11.6 vs. 15.6 days; P < 0.001) and the early follicular phase mean FSH and mean E levels were higher (9.3 vs. 6.6 mIU/mL and 305 vs. 160 pmol/L; P < 0.01) in the older (O) group compared to the younger group. There was a strong trend toward higher FF mean E (2280 vs. 1931 nmol/L) and lower FF mean T (978 vs. 2361 pmol/L) levels in group O. The E/T ratio was significantly higher (5253 vs. 2408; P < 0.03) in group O. In group O, the mean FF P levels were increased as well (25.1 vs. 18.8 micromol/L; P < 0.01). The serum mean IGF-I (153 vs. 226 ng/mL; P < 0.001) and FF mean IGF-I (113 vs. 158 ng/mL; P < 0.02) levels were significantly decreased in group O. There were no differences between groups in serum or FF IGF-II or inhibin levels. Whether reproductive aging is an intrinsic ovarian process or the ovary is simply responding to exogenous influences, the ovary in general and its follicles in particular are the primary site of the effects of aging. Ovarian follicles in older ovulatory women have some unique features: 1) the follicles are the same size as those in younger women, but form more rapidly; 2) secretion of E and inhibin is not compromised; 3) the concentrations of steroids in the FF are indicative of a healthier follicle, i.e. increased P levels and higher estrogen to androgen ratio; and 4) serum and FF levels of IGF-I are decreased, but there are no differences in IGF-II levels.


Assuntos
Envelhecimento/fisiologia , Líquido Folicular/metabolismo , Substâncias de Crescimento/metabolismo , Folículo Ovariano/fisiologia , Adulto , Androstenodiona/sangue , Estradiol/sangue , Feminino , Hormônio Foliculoestimulante/sangue , Humanos , Inibinas/sangue , Fator de Crescimento Insulin-Like I/metabolismo , Fator de Crescimento Insulin-Like II/metabolismo , Hormônio Luteinizante/sangue , Ciclo Menstrual/fisiologia , Pessoa de Meia-Idade , Progesterona/sangue , Sucção , Testosterona/sangue
13.
Clin Endocrinol (Oxf) ; 44(3): 285-92, 1996 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8729523

RESUMO

OBJECTIVE: Women experience an age-related decline in fertility despite regular ovulatory cycles and normal production of ovarian steroids. Growth hormone and IGF-I are both reported to decline with age, and there is evidence that both hormones promote intraovarian actions of gonadotrophins. The purpose of this study was to characterize circulating levels of GH and IGF-I in normal, older reproductive age women with ovulatory cycles. DESIGN: Prospective, controlled. PATIENTS: Twenty-eight regularly cycling older (n = 16) and younger (n = 12) women were recruited for daily blood sampling throughout a menstrual cycle. MEASUREMENTS: Serum obtained from daily blood sampling was analysed for LH, FSH, oestradiol (E2) and progesterone (P). Serum obtained from frequent sampling during the admission was analysed for pulsatile GH secretion. IGF-I and GH binding protein (GHBP) were also measured in subsets of the two age groups. RESULTS: All subjects exhibited normal patterns of LH, FSH, E2 and P consistent with ovulatory cycles. There were no differences between the two age groups in integrated 24-hour GH secretion or in GH pulse amplitude or frequency. There were no differences in GH secretion between the early follicular and miduluteal phases when data were combined for the two subject groups. Plasma concentrations of IGF-I were significantly lower throughout the cycle in the older women. There were no significant differences in levels of GHBP across the cycle or between the two age groups. CONCLUSIONS: IGF-I decreases with age in women without identifiable changes in the amount or pattern of GH secretion or in circulating GHBP concentrations. Decreased IGF-I production may be related to decreased ovarian gonadotrophin sensitivity in older reproductive age women.


Assuntos
Envelhecimento/sangue , Proteínas de Transporte/sangue , Hormônio do Crescimento/sangue , Fator de Crescimento Insulin-Like I/análise , Ciclo Menstrual/sangue , Adulto , Estradiol/sangue , Feminino , Hormônio Foliculoestimulante/sangue , Humanos , Hormônio Luteinizante/sangue , Pessoa de Meia-Idade , Progesterona/sangue , Estudos Prospectivos
14.
Obstet Gynecol ; 87(1): 13-7, 1996 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8532248

RESUMO

OBJECTIVE: To assess the predictive value of monitoring urine LH at home using a rapid, colorimetric enzyme immunoassay test (Ovuquick) once every evening. METHODS: Twenty-six strictly defined normal women with no history of infertility were enrolled in studies involving urine LH tests. Each subject had transvaginal sonography and serum LH tests performed two times per day beginning in the middle of a normal menstrual cycle. All subjects performed urine LH testing at home every evening. The time of the peak serum LH measurement was considered the surge. Ovulation was determined using sonographic criteria with confirmation by normal luteal-phase progesterone levels (3 ng/mL or greater). Two clinically relevant intervals were determined: interval I, time from peak serum LH to positive urine LH, and interval II, time from positive urine LH to follicular collapse by ultrasonography. RESULTS: All 26 cycles examined were ovulatory, based on sonographic and progesterone level criteria. The mean time (+/- standard error of the mean [SEM]) for interval I was 2 +/- 2 hours (95% confidence interval [CI] -2 to 6). The mean time (+/- SEM) for interval II was 20 +/- 3 hours (95% CI 14-26). Positive predictive values for follicular collapse within 24 or 48 hours after positive urine LH testing were 73 and 92%, respectively. CONCLUSION: Urine LH testing every evening is a reliable method of predicting ovulation within the ensuing 48 hours.


Assuntos
Hormônio Luteinizante/urina , Menstruação/urina , Ovulação , Kit de Reagentes para Diagnóstico , Feminino , Humanos , Valor Preditivo dos Testes , Estudos Retrospectivos
15.
FEMS Microbiol Lett ; 71(2): 199-203, 1992 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-1601289

RESUMO

The hinge in IgA1 and the linker in endoglucanase A (CenA) are quite similar. The IgA1 hinge is 18 amino acids long and contains only proline, threonine and serine. The linker in CenA is 27 amino acids long and contains only proline, threonine and a single serine. IgA proteases from Neisseria gonorrhoeae cleave Pro-Ser and Pro-Thr bonds within the IgA1 hinge sequence, but they do not attack CenA. When the linker sequence of CenA is replaced with the hinge sequence of IgA1, the hybrid polypeptide is susceptible to the N. gonorrhoeae proteases. It is cleaved within the hinge sequence at the same sites as IgA1.


Assuntos
Bactérias/enzimologia , Celulase/metabolismo , Neisseria gonorrhoeae/enzimologia , Peptídeo Hidrolases/metabolismo , Serina Endopeptidases , Sequência de Aminoácidos , Sequência de Bases , Dados de Sequência Molecular , Proteínas Recombinantes/metabolismo , Homologia de Sequência do Ácido Nucleico , Especificidade por Substrato
16.
Nucleic Acids Res ; 13(7): 2559-68, 1985 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-2987859

RESUMO

The modified base alpha-putrescinylthymine (putT) in phi W-14 DNA blocks cleavage of the DNA by 17 of 32 Type II restriction endonucleases. The enzymes cleaving the DNA do so to widely varying extents. The frequencies of cleavage of three altered forms of the DNA show that putT blocks recognition sites either when it occurs within the site or when it is in a sequence flanking the site. The blocking is dependent on both charge and steric factors. The charge effects can be greater than the steric effects for some of the enzymes tested. All the enzymes cleaving phi W-14 DNA release discrete fragments, showing that the distribution of putT is ordered. The cleavage frequencies for different enzymes suggest that the sequence CAputTG occurs frequently in the DNA. Only TaqI of the enzymes tested appeared not to be blocked by putT, but it was slowed down. TaqI generated fragments are joinable by T4 DNA ligase.


Assuntos
Bacteriófagos/genética , Enzimas de Restrição do DNA/metabolismo , DNA Viral/análise , Desoxirribonucleases de Sítio Específico do Tipo II , Timina/análogos & derivados , Sequência de Bases , Sítios de Ligação , Eletroforese em Gel de Ágar , Timina/farmacologia
17.
J Virol ; 52(3): 1036-8, 1984 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-6492260

RESUMO

Normal levels of the hypermodified pyrimidine, alpha-putrescinylthymine, which is formed from hydhydroxymethyluracil at the polynucleotide level (Maltman et al., J. Virol. 34:354-359, 1984), are not required in bacteriophage luminal diameterW-14 DNA for the DNA to serve as a replicative template in luminal diameterW-14-infected cells.


Assuntos
Bacteriófagos/genética , DNA Viral/biossíntese , Pseudomonas/genética , Timina/análogos & derivados , Replicação do DNA , Mutação , Timina/biossíntese , Replicação Viral
18.
J Virol ; 50(2): 529-32, 1984 May.
Artigo em Inglês | MEDLINE | ID: mdl-6708173

RESUMO

The latent period of bacteriophage phi W-14 is approximately 65 min when the doubling time of its host, Pseudomonas acidovorans, is 85 min. Host protein synthesis is shut off relatively slowly, stopping approximately 25 min after infection. There are several phases of phage-specific polypeptide synthesis during the latent period: early polypeptides appear within 10 min after infection; middle polypeptides start to appear between 10 nd 30 min; late polypeptides appear after 30 min. The lengths of time for which individual polypeptides are synthesized vary widely. Several late polypeptides do not appear in the virion. DNA replication is not required for late gene expression. The hypermodified pyrimidine, alpha-putrescinylthymine, appears not to be required in both strands of the DNA duplex for transcription.


Assuntos
Bacteriófagos/genética , Replicação do DNA , Mutação , Peptídeos/genética , Pseudomonas/genética , Proteínas Virais/genética , Eletroforese em Gel de Poliacrilamida , Cinética , Peso Molecular , Peptídeos/isolamento & purificação , Proteínas Virais/isolamento & purificação
19.
J Virol ; 47(3): 399-405, 1983 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-6620460

RESUMO

The DNA synthesized in the nonpermissive host by the noncomplementing mutants am36 and am42 of bacteriophage phi W-14 contains about half the wild-type level of alpha-putrescinylthymine (putThy) and a correspondingly greater level of thymine. The mechanisms whereby thymine nucleotides are excluded from replicating DNA are functional in both mutants because neither of them incorporates exogenous thymidine into DNA. It is proposed that (i) in wild-type phi W-14, the conversion of hydroxymethyluracil to putThy at the polynucleotide level is sequence specific, but that to thymine is nonspecific; and (ii) in the mutants, the sequence-specific recognition is impaired so that more thymine and less putThy are formed. The thymine-rich DNA can be packaged into phage particles. In the case of am42, the phage particles are morphologically indistinguishable from and have essentially the same polypeptide composition as wild-type particles. However, the DNA molecules they contain are about 11% shorter than those in wild-type phage, am42rev4, a revertant of am42, contains DNA with about 70% of the normal level of putThy; these molecules are about 3% shorter than wild-type DNA. The properties of am42 and am42rev4 are consistent with the suggestion that putThy facilitates the very tight packing of phi W-14 DNA (Scraba et al., Virology 124:152-160, 1983). It also appears that the putThy content of phi W-14 DNA can be reduced by no more than 30% without adversely affecting the production of viable progeny; for example, the burst size of am42rev4 is about 25% of that of the wild type.


Assuntos
Bacteriófagos/fisiologia , DNA Viral/metabolismo , Timina/análogos & derivados , Bacteriófagos/genética , Composição de Bases , Sequência de Bases , DNA Viral/análise , Mutação , Pseudomonas , Timina/biossíntese , Timina/fisiologia , Proteínas Virais/análise , Proteínas Estruturais Virais
20.
J Virol ; 43(1): 67-72, 1982 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-7109031

RESUMO

Of 42 amber mutants of bacteriophage phi W-14, 6 were defective in DNA synthesis. Three of the mutants synthesized DNA in the nonpermissive host, but were defective in post-replicational modification of the DNA. The DNA synthesized by two of these mutants, am36 and am42, contained more thymine and less alpha-putrescinylthymine than did wild-type DNA; that synthesized by the third mutant, am37, contained the normal amount of thymine, no alpha-putrescinylthymine, and hydroxymethyluracil. The properties of these mutants suggested that the presence of the normal amount of alpha-putrescinylthymine in phi W-14 DNA was essential for the production of viable progeny. Three of the mutants, am6, am35, and am45, failed to synthesize DNA in the nonpermissive host. These mutants were analogous to the DNA off mutants of T4. Nonpermissive cells infected with DNA off mutants accumulated dATP, dGTP, dCTP, and hydroxymethyl dUTP, but not dTTP or alpha-putrescinyldeoxythymidine triphosphate, confirming that both thymine and alpha-putrescinylthymidine in phi W-14 DNA are formed from hydroxymethyluracil at the polynucleotide level. The synthesis of phi W-14 DNA is unusual because (i) thymine is formed from hydroxymethyluracil at the polynucleotide level, (ii) the hypermodification forming alpha-putrescinylthymine is essential, and (iii) thymine and alpha-putrescinylthymine must be made in the correct proportions. Complementation tests showed that the mutants defined three genes involved in DNA polymerization and two genes involved in post-replicational modification.


Assuntos
Bacteriófagos/genética , DNA Viral/biossíntese , Genes Virais , Bacteriófagos/metabolismo , Centrifugação com Gradiente de Concentração , Teste de Complementação Genética , Mutação , Pseudomonas , Uracila/metabolismo
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