RESUMO
Existing crop monitoring programs determine the incidence and distribution of plant diseases and pathogens and assess the damage caused within a crop production region. These programs have traditionally used observed or predicted disease and pathogen data and environmental information to prescribe management practices that minimize crop loss. Monitoring programs are especially important for crops with broad geographic distribution or for diseases that can cause rapid and great economic losses. Successful monitoring programs have been developed for several plant diseases, including downy mildew of cucurbits, Fusarium head blight of wheat, potato late blight, and rusts of cereal crops. A recent example of a successful disease-monitoring program for an economically important crop is the soybean rust (SBR) monitoring effort within North America. SBR, caused by the fungus Phakopsora pachyrhizi, was first identified in the continental United States in November 2004. SBR causes moderate to severe yield losses globally. The fungus produces foliar lesions on soybean (Glycine max) and other legume hosts. P. pachyrhizi diverts nutrients from the host to its own growth and reproduction. The lesions also reduce photosynthetic area. Uredinia rupture the host epidermis and diminish stomatal regulation of transpiration to cause tissue desiccation and premature defoliation. Severe soybean yield losses can occur if plants defoliate during the mid-reproductive growth stages. The rapid response to the threat of SBR in North America resulted in an unprecedented amount of information dissemination and the development of a real-time, publicly available monitoring and prediction system known as the Soybean Rust-Pest Information Platform for Extension and Education (SBR-PIPE). The objectives of this article are (i) to highlight the successful response effort to SBR in North America, and (ii) to introduce researchers to the quantity and type of data generated by SBR-PIPE. Data from this system may now be used to answer questions about the biology, ecology, and epidemiology of an important pathogen and disease of soybean.
RESUMO
Mutations in the spindle checkpoint genes can cause improper chromosome segregations and aneuploidies, which in turn may lead to reproductive problems. Two of the proteins involved in this checkpoint are Aurora kinase B (AURKB), preventing the anaphase whenever microtubule-kinetochore attachments are not the proper ones during metaphase; and synaptonemal complex protein 3 (SYCP3), which is essential for the formation of the complex and for the recombination of the homologous chromosomes. This study has attempted to clarify the possible involvement of both proteins in the reproductive problems of patients with chromosomal instability. In order to do this, we have performed a screening for genetic variants in AURKB and SYCP3 among these patients using Sanger sequencing. Only one apparently non-pathogenic deletion was found in SYCP3. On the other hand, we found six sequence variations in AURKB. The consequences of these changes on the protein were studied in silico using different bioinformatic tools. In addition, the frequency of three of the variations was studied using a high-resolution melting approach. The absence of these three variants in control samples and their position in the AURKB gene suggests their possible involvement in the patients' chromosomal instability. Interestingly, two of the identified changes in AURKB were found in each member of a couple with antecedents of spontaneous pregnancy loss, a fetal anencephaly and a deaf daughter. One of these changes is described here for the first time. Although further studies are necessary, our results are encouraging enough to propose the analysis of AURKB in couples with reproductive problems.
Assuntos
Proteínas Nucleares/genética , Proteínas Serina-Treonina Quinases/genética , Reprodução/fisiologia , Aurora Quinase B , Aurora Quinases , Proteínas de Ciclo Celular , Instabilidade Cromossômica/genética , Proteínas de Ligação a DNA , Feminino , Humanos , Masculino , Mutação , Gravidez , Reprodução/genéticaRESUMO
Recent, successful application of assisted reproductive technologies in captive beluga has resulted from the extensive study of male beluga reproductive biology. Optimization of assisted reproduction requires additional detailed knowledge of the female estrous cycle. Our specific objectives were to: (1) validate urinary immunoassays for use in this species; (2) elucidate annual ovarian cycle dynamics through the combined use of hormone excretion patterns and transabdominal ultrasound; and (3) establish whether ovulation in this species is spontaneous or induced by male factors. Ovulation was observed in four of 15 estrous cycles monitored in four adult female beluga maintained in a single-sex group. After introduction of a breeding male, ovulation was observed in six of seven estrous cycles. All estrous cycles occurred from March through June. For spontaneous ovulations (n=4), the inter-estrous interval was 34d (range 33-35d), with a follicular phase length (FPL) of 25±8d (mean±SD). For all ovulatory estrous cycles (with and without a breeding male), urinary estrogen conjugates (EC, 15.3±7.9ng/mg Cr) and ovulatory luteinizing hormone (ovLH, 17.1±6.6ng/mg Cr) concentrations both peaked on Day 0, and EC concentrations returned to baseline 8±7d later. For non-conceptive cycles, urinary progestagen (Pg) concentrations increased on Day 0 (3.5±1.7ng/mg Cr), peaked on Day+19 (19.7±17.1ng/mg Cr), and were elevated above baseline for 27±4d. Preovulatory follicular diameter and circumference on Day -2±2 (range: Day -4 to -1) from peak EC were 2.5±0.7 and 7.8±1.3cm, respectively. The FPL in non-ovulatory estrous cycles (n=11) lasted 24±10d and EC concentrations gradually declined to baseline over a 21±10d interval following the EC peak (27.8±28.8ng/mg Cr). Non-ovulatory estrous cycles were characterized by the absence of an ovLH surge and no concomitant increase in Pg concentrations above baseline excretion; the mean follicular diameter at or near peak EC was 3.1±0.8cm on Day 2 ±3d from peak EC (range: -1 to +5days from peak EC). Overall, these data confirm that captive beluga exhibit reproductive seasonality and demonstrate that the species is a facultative-induced ovulator.
Assuntos
Beluga/fisiologia , Ciclo Estral/fisiologia , Hormônios Esteroides Gonadais/urina , Ovário/diagnóstico por imagem , Ovulação/fisiologia , Comportamento Sexual Animal/fisiologia , Animais , Estrogênios/urina , Feminino , Imunoensaio , Hormônio Luteinizante/urina , Masculino , Progestinas/urina , Prolactina/urina , Reprodutibilidade dos Testes , UltrassonografiaRESUMO
This paper evaluates the lethal effectiveness on 7 different Salmonella serovars of the application, in static and continuous conditions, of pulsed electric fields (PEF) followed by heat treatments in liquid whole egg (LWE) with additives (EDTA or triethyl citrate-TC-). Compared to heat treatments, the PEF (25 kV/cm and 75-100 kJ/kg) followed by heat (52°C/3.5', 55°C/2', or 60°C/1') in LWE with 2% TC permitted the reduction of heat treatment time from 92 fold at 52°C to 3.4 fold at 60°C, and 4.8 fold at 52°C in LWE with EDTA for a 9-Log(10) reduction of the population of Salmonella Enteritidis. The new designed treatments inactivated more than 5 Log(10) cycles of Salmonella serovars Dublin, Enteritidis 4300, Enteritidis 4396, Typhimurium, Typhi, Senftenberg, and Virchow, both in static and continuous conditions. Conversely, current heat pasteurization treatments of 60°C/3.5' and 64°C/2.5' reduced 5 Log(10) cycles of various serovars of Salmonella but only 2 and 3-4 Log(10) cycles of Salmonella Senftenberg and Salmonella Enteritidis 4396, respectively. Soluble protein content (SPC) decreased 1.8%, 1.3%, and 5.0% after the successive application of PEF followed by heat at 52, 55, and 60°C in the presence of 2% TC, respectively, whereas 1.6% and 9.4% of SPC were reduced after heat pasteurization at 60 and 64°C, respectively. Results indicate that designed treatments could be an alternative to current heat pasteurization of LWE as showed higher lethal effectiveness against Salmonella serovars with a similar or even lower decrement of the soluble protein content.
Assuntos
Ovos/microbiologia , Aditivos Alimentares/farmacologia , Pasteurização/métodos , Salmonella/crescimento & desenvolvimento , Proteínas do Ovo/análise , Ovos/análise , Eletricidade , Temperatura AltaRESUMO
Several authors have attempted to construct a phenotype map for duplications of different portions of chromosome 18 to identify a possible critical region (CR) for Edwards Syndrome. Partial duplications of 18q have been reported in the literature involving the distal CR in patients with some clinical features of Edwards Syndrome. Here, we describe a phenotypically normal male with a large duplication on chromosome 18 that involves the proposed distal CR. The lack of clinical features is remarkable, except for pathological semen analysis, which suggests that terminal 17.4 Mb of 18q do not contain the Edwards Syndrome CR. Alternatively, unknown modifier factors or undetected somatic mosaicism might cause incomplete penetrance of this duplication.
Assuntos
Astenozoospermia/genética , Duplicação Cromossômica , Cromossomos Humanos Par 18 , Oligospermia/genética , Adulto , Astenozoospermia/complicações , Humanos , Masculino , Oligospermia/complicações , FenótipoRESUMO
Loss-of-function mutations of the MECP2 gene are the cause of most cases of Rett syndrome in females, a progressive neurodevelopmental disorder characterized by severe mental retardation, global regression, hand stereotypies, and microcephaly. On the other hand, gain of dosage of this gene causes the MECP2 duplication syndrome in males characterized by severe mental retardation, absence of speech development, infantile hypotonia, progressive spasticity, recurrent infections, and facial dysmorphism. Female carriers of a heterozygous duplication show a skewed X-inactivation pattern which is the most probable cause of the lack of clinical symptoms. In this paper, we describe a girl with a complex de novo copy number gain at Xq28 and non-skewed X-inactivation pattern that causes mental retardation and motor and language delay. This rearrangement implies triplication of the MECP2 and IRAK1 genes, but it does not span other proximal genes located in the common minimal region of patients affected by the MECP2 duplication syndrome. We conclude that the triplication leads to a severe phenotype due to random X-inactivation, while the preferential X chromosome inactivation in healthy carriers may be caused by a negative selection effect of the duplication on some proximal genes like ARD1A or HCFC1.
Assuntos
Duplicação Gênica , Deficiência Intelectual Ligada ao Cromossomo X/genética , Proteína 2 de Ligação a Metil-CpG/genética , Inativação do Cromossomo X , Anormalidades Múltiplas/genética , Anormalidades Múltiplas/patologia , Criança , Deficiências do Desenvolvimento/patologia , Face/anormalidades , Feminino , Humanos , Hibridização in Situ Fluorescente , SíndromeAssuntos
Adjuvantes Anestésicos/efeitos adversos , Transtornos da Alimentação e da Ingestão de Alimentos/induzido quimicamente , Parassonias/induzido quimicamente , Oxibato de Sódio/efeitos adversos , Adjuvantes Anestésicos/uso terapêutico , Adulto , Feminino , Humanos , Narcolepsia/tratamento farmacológico , Oxibato de Sódio/uso terapêuticoRESUMO
Despite the importance of the western white-bearded wildebeest (Connochaetes taurinus mearnsi) to the Serengeti-Mara ecosystem, surprisingly little is known about the reproductive physiology of this keystone species. A longitudinal, non-invasive endocrine study was conducted on female wildebeest captured from the Serengeti-Mara migration and maintained for approximately 16 months in large fenced enclosures within the species' natural range. An intact bull was introduced to a female subgroup (n=5), while remaining females (n=10) were unexposed to a male. Fecal progestagen patterns reflected ovarian activity and pregnancy. In non-pregnant animals, luteal and inter-luteal baseline progestagen values differed (p<0.001) over time, thereby allowing identification of recurrent estrous cycles. The average durations of the luteal phase, estrous cycle, gestation, and post-partum anestrus were 14.3+/-0.5, 22.6+/-1.0, 240.8+/-11.7, and 104.1+/-15.6 d, respectively. Annual reproductive patterns indicated a distinctive period of ovarian activity that extended from 13 May through 3 December (203.5+/-29.9 d) with all unmated females displaying from one to 14 estrous cycles. Progestagens were higher (p <0.001) in pregnant (n=4) than non-pregnant (n=10) cows. These data (1) reveal the value of fecal hormone monitoring for establishing the first ever endocrine profiles of female wildebeest in semi-free-living conditions in their native range, and (2) indicate that the species is a seasonal breeder that is polyestrous and a spontaneous ovulator.
Assuntos
Ciclo Estral/metabolismo , Progestinas/metabolismo , Reprodução/fisiologia , Ruminantes/metabolismo , Animais , Cruzamento , Ecossistema , Fezes/química , Feminino , Quênia , Lactação , Fase Luteal/metabolismo , Masculino , Parto , Gravidez , Progestinas/análise , Estações do Ano , TanzâniaRESUMO
This investigation evaluated the lethal efficiency of pulsed electric fields (PEFs) to pasteurize liquid whole egg (LWE). To achieve this aim, we describe the inactivation of Salmonella Enteritidis and the heat resistant Salmonella Senftenberg 775 W in terms of treatment time and specific energy at electric field strengths ranging from 20 to 45 kV/cm. Based on our results, the target microorganism for this technology in LWE varied with intensity of the PEF treatment. For electric field strengths greater than 25 kV/cm, Salmonella Enteritidis was the most PEF-resistant strain. For this Salmonella serovar the level of inactivation depended only on the specific energy applied: i.e., 106, 272, and 472 kJ/kg for 1, 2, and 3 Log(10) reductions, respectively. The developed mathematical equations based on the Weibull distribution permit estimations of maximum inactivation level of 1.9 Log(10) cycles of the target Salmonella serovar in the best-case scenario: 250 kJ/kg and 25 kV/cm. This level of inactivation indicates that PEF technology by itself cannot guarantee the security of LWE based on USDA and European regulations. The occurrence of cell damage due to PEF in the Salmonella population opens the possibility of designing combined processes enabling increased microbial lethality in LWE.
Assuntos
Ovos/microbiologia , Estimulação Elétrica , Conservação de Alimentos/métodos , Intoxicação Alimentar por Salmonella/prevenção & controle , Salmonella enteritidis/crescimento & desenvolvimento , Animais , Galinhas , Contagem de Colônia Microbiana , Indústria de Processamento de Alimentos/métodos , Indústria de Processamento de Alimentos/normas , Humanos , Salmonella , Fatores de TempoRESUMO
Submicroscopic deletions of 1q44-qter cause severe mental retardation, profound growth retardation, microcephaly and corpus callosum hypo/agenesis in most patients. At least 3 intervals in 1q44 have been described as critical regions containing genes leading to corpus callosum abnormalities. In this report we describe a patient with a de novo small interstitial 1q44 deletion of 1,152 kb detected with 44K oligonucleotide array-CGH (44K Agilent Technologies) and a mild phenotype lacking corpus callosum abnormalities. The first deleted oligonucleotide was located at 242.638 Mb (within the ADSS gene), and the last deleted oligonucleotide at 243.791 Mb (within the KIF26B gene). The clinical and molecular findings of the patient here reported remain consistent with a role for the AKT3 or ZNF238 genes in corpus callosum development.
Assuntos
Agenesia do Corpo Caloso , Deleção Cromossômica , Cromossomos Humanos Par 1 , Criança , Corpo Caloso/metabolismo , Humanos , Imageamento por Ressonância Magnética , MasculinoRESUMO
Chromosomal rearrangements in the short arm of chromosome 4 can result in 2 different clinical entities: Wolf-Hirschhorn syndrome (WHS), characterized by severe growth delay, mental retardation, microcephaly, 'Greek helmet' facies, and closure defects, or partial 4p trisomy, associated with multiple congenital anomalies, mental retardation, and facial dysmorphisms. We present clinical and laboratory findings in a patient who showed a small duplication in 4p16.3 associated with a subtle terminal deletion in the same chromosomal region. GTG-banding analyses, multiplex ligation-dependent probe amplification analyses, and studies by array-based comparative genomic hybridization were performed. The results of the analyses revealed a de novo 1.3 Mb deletion of the terminal 4p and a 1.1 Mb duplication in our patient, encompassing the WHS critical region. Interestingly, this unusual duplication/deletion rearrangement results in an intermediate phenotype that shares characteristics of the WHS and the 4p trisomy syndrome. The use of novel technologies in the genetic diagnosis leads to the description of new clinical syndromes; there is a growing list of microduplication syndromes. Therefore, we propose that overexpression of candidate genes in WHS (WHSC1, WHSC2 and LETM1) due to a duplication causes a clinical entity different to both the WHS and 4p trisomy syndrome.
Assuntos
Deleção Cromossômica , Cromossomos Humanos Par 4 , Duplicação Gênica , Trissomia , Síndrome de Wolf-Hirschhorn/genética , Proteínas de Ligação ao Cálcio/genética , Criança , Hibridização Genômica Comparativa , Histona-Lisina N-Metiltransferase/genética , Humanos , Masculino , Proteínas de Membrana/genética , Fenótipo , Proteínas Repressoras/genética , Fatores de Elongação da Transcrição/genéticaRESUMO
"Limited control" models of reproductive skew in cooperative societies suggest that the frequency of breeding by subordinates is determined by the outcome of power struggles with dominants. In contrast, "optimal skew" models suggest that dominants have full control of subordinate reproduction and allow subordinates to breed only when this serves to retain subordinates' assistance with rearing dominants' own litters. The results of our 7-year field study of cooperative meerkats, Suricata suricatta, support the predictions of limited control models and provide no indication that dominant females grant reproductive concessions to subordinates to retain their assistance with future breeding attempts.
Assuntos
Carnívoros/fisiologia , Comportamento Cooperativo , Dominação-Subordinação , Reprodução , Comportamento Sexual Animal , África Austral , Envelhecimento , Animais , Comportamento Animal , Peso Corporal , Feminino , Masculino , Modelos Biológicos , Chuva , Estações do AnoRESUMO
This report describes a case of mosaic Down syndrome due to an unusual karyotype in a patient conceived by assisted reproductive techniques and cryopreservation. The chromosomal complement consists of two different cell lines, one predominantly trisomic with a derivative chromosome due to a Robertsonian translocation (21;21) and another carrying a ring chromosome 21. The present work analyses the different mechanisms that could have led to mosaicism.
Assuntos
Cromossomos Humanos Par 21 , Criopreservação , Síndrome de Down/diagnóstico , Embrião de Mamíferos , Fertilização in vitro , Translocação Genética , Síndrome de Down/etiologia , Síndrome de Down/genética , Fertilização/fisiologia , Fertilização in vitro/efeitos adversos , Humanos , Masculino , Mosaicismo , Cromossomos em Anel , Translocação Genética/genéticaRESUMO
BACKGROUND: Mental retardation can be caused by copy number variations (deletions, insertions, duplications), ranging in size from 1 kb to several megabases. Array based comparative genomic hybridisation (array-CGH) allows detection of an increasing number of genomic alterations. METHODS: A series of 46 patients with mental retardation and congenital abnormalities (previously screened for subtelomeric rearrangements) were evaluated for cryptic chromosomal imbalances by array-CGH. This array contains 6465 large-insert BAC/PAC clones, representing sequences uniformly distributed throughout the human genome. The results were confirmed by alternative techniques. RESULTS: Four pathogenic rearrangements were detected: two of them were novel, a deletion at 2q31.2 and a duplication at 8q12 band; the other two have been previously reported--a duplication of the Williams-Beuren region and a deletion of 3q29. By adding the subtelomeric alterations previously identified, a total rate of 18% of pathogenic rearrangements was found in the series. CONCLUSION: Based on our results, ZNF533 is the only gene contained in the overlapping region with other deletions at 2q31.2, and it is most probably the fourth zinc-finger gene implied in mental retardation. On the other hand, we propose that the CHD7 gene, associated with CHARGE syndrome by haploinsufficiency, causes a different phenotype by gain-of-dosage.
Assuntos
Anormalidades Múltiplas/genética , Aberrações Cromossômicas , Deficiência Intelectual/genética , Dedos de Zinco/genética , Adolescente , Criança , Pré-Escolar , Cromossomos Humanos , DNA/química , DNA/genética , Feminino , Deleção de Genes , Dosagem de Genes , Rearranjo Gênico , Humanos , Masculino , Hibridização de Ácido Nucleico/métodos , Análise de Sequência com Séries de OligonucleotídeosRESUMO
BACKGROUND: Neurotoxic cancer treatments can cause chemotherapy-induced peripheral neuropathy and postural control deficits that cancer survivors report as a concern. Exercise-based sensorimotor training has emerged as a promising treatment for symptoms including balance deficits, however, more study is needed to optimize engagement and participation. We evaluated feasibility, satisfaction, and preliminary efficacy of a novel balance training program for cancer survivors: partnered, Adapted Argentine Tango dance (Tango). METHODS: Twenty-two individuals participated (nâ¯=â¯22). Tango classes (1â¯h) were offered twice/week. At baseline, midpoint (8 classes), and conclusion of the training (15 or 16 classes), we assessed postural control by measuring center-of-pressure (CoP) measures during quiet standing with eyes closed. We also documented attendance, barriers to attendance, and satisfaction (7 point scale; 1 high). At conclusion, we analyzed whether 1) attendance and satisfaction met feasibility criteria; 2) postural control improved among participants who were outside of normal range at baseline; and 3) co-enrolling with a companion increased attendance. FINDINGS: Feasibility criteria were met: more than half of participants attended more than half the classes offered with a mean satisfaction rate of 1.2 (SD 0.4). Those who enrolled with a companion (nâ¯=â¯9) attended more sessions than those who did not (nâ¯=â¯13) (Mann-Whitney U valueâ¯=â¯20; pâ¯=â¯0.012). Participants with demonstrated deficits (nâ¯=â¯9) improved in 3 CoP measures at midpoint (i.e., medial-lateral sway, ellipse area, medial-lateral velocity), retaining improvement in 2 CoP measures at endpoint (i.e., medial-lateral sway, ellipse area). INTERPRETATION: Partnered, Adapted Argentine Tango is feasible for cancer survivors and may improve postural control. Enrolling with a companion improved attendance.
Assuntos
Sobreviventes de Câncer , Dançaterapia/métodos , Neoplasias/fisiopatologia , Equilíbrio Postural , Adulto , Idoso , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/reabilitação , Doenças do Sistema Nervoso Periférico , Projetos Piloto , Resultado do TratamentoRESUMO
The prenatal cytogenetic study of an amniotic fluid sample of a 39-year-old female showed one X chromosome with a fragment of extra material in the short arm. The G-band pattern suggested that the extra material could be the long arm of an X chromosome. Several complementary studies were performed in order to better clarify the origin of the material. These studies included parental karyotypes, microsatellite typing and comparative genomic hybridization (CGH). The results obtained allowed us to conclude that the derivative chromosome arose de novo as a recombinant X chromosome with duplication of Xq and partial deletion of Xp. Once informed, the parents decided to continue with the pregnancy, after which a healthy girl was born with no apparent disorders.
Assuntos
Bandeamento Cromossômico , Cromossomos Humanos X , Diagnóstico Pré-Natal/métodos , Recombinação Genética , Adulto , Feminino , Duplicação Gênica , Humanos , Recém-Nascido , Hibridização de Ácido Nucleico , Gravidez , Deleção de SequênciaRESUMO
Longitudinal serum testosterone concentrations (n=10 males) and semen production (n=2 males) in killer whales were evaluated to: (1) characterize fluctuations in serum testosterone concentrations with respect to reproductive maturity and season; (2) compare morphologic changes to estimated age of sexual maturity, based on changes in serum testosterone concentrations; and (3) evaluate seasonal changes in sperm production. Classification of reproductive status and age class was based on differences (P < 0.05) in serum testosterone concentrations according to age; juvenile males ranged from 1 to 7 years (mean+/-S.D. testosterone, 0.13+/-0.20 ng/mL), pubertal males from 8 to 12 years (2.88+/-3.20 ng/mL), and sexually mature animals were 13 years and older (5.57+/-2.90 ng/mL). For captive-born males, serum testosterone concentrations, total body length and height to width ratio of the dorsal fin were 0.7+/-0.7 ng/mL, 495.6+/-17.5 cm and 1.14+/-0.13c m, respectively, at puberty; at sexual maturity, these end points were 6.0+/-3.3 ng/mL, 548+/-20 cm and 1.36+/-0.1cm. Serum testosterone concentrations were higher (P<0.05) from March to June than from December to February in pubertal animals (4.2+/-3.4 ng/mL versus 1.4+/-2.6 ng/mL) and than from September to December in sexually mature animals (7.2+/-3.3 ng/mL versus 4.0+/-2.0 ng/mL). Ejaculates (n = 90) collected from two males had similar (P > 0.05) sperm concentrations across all months. These data represent the first comprehensive study on male testosterone concentrations during and after sexual maturation, and on reproductive seasonality in the killer whale.
Assuntos
Envelhecimento/fisiologia , Reprodução/fisiologia , Maturidade Sexual/fisiologia , Testosterona/sangue , Orca/fisiologia , Animais , Masculino , Estações do Ano , Contagem de Espermatozoides/veterinária , Orca/sangueRESUMO
To evaluate the in vivo effect of delta 1-testololactone on peripheral aromatization, studies were performed on seven postmenopausal women with metastatic breast cancer. Analysis of variance indicated that there were significant increases of circulating androstenedione (p less than 0.05) and estradiol (p less than 0.001) during administration of different doses of testololactone. Androstenedione levels were increased with all doses of testololactone tested (50, 100, 250, and 500 mg every 6 hr for 14 days each), while estradiol rose with only the 250- and 500-mg dosages. With administration, there was a significant decrease of estrone (p less than 0.001) with the mean level falling from 26 +/- 3 (S.E.) to 11 +/- 2 pg/ml. The addition of adrenal suppression (dexamethasone, 1 mg nightly at 11 p.m.) significantly lowered androstenedione (p less than 0.05) but had no effect on estrone or estradiol levels. Long-term therapy (up to 6 months) with the 250-mg dosage showed continual suppression of estrone with no escape being observed. Studies to determine the reason for the increase of estradiol with testololactone suggested cross-reactivity of the antibody with in vivo metabolites of the drug. However, these possible metabolites did not bind to uterine cytosol estrogen receptors. The decrease in estrone with testololactone administration presumably explains its antitumor properties.
Assuntos
Aromatase/metabolismo , Neoplasias da Mama/enzimologia , Oxirredutases/metabolismo , Testolactona/análogos & derivados , Idoso , Androstenodiona/sangue , Dexametasona/farmacologia , Relação Dose-Resposta a Droga , Estradiol/sangue , Estrona/sangue , Feminino , Humanos , Menopausa , Pessoa de Meia-Idade , Testolactona/farmacologia , Testosterona/sangueRESUMO
The circadian glucocorticoid rhythm provides important information on the functioning of the hypothalamic-pituitary-adrenal axis in individuals. Frequent repeated blood sampling can limit the kinds of studies conducted on this rhythm, particularly in small laboratory rodents that have limited blood volumes and are easily stressed by handling. We developed an extraction and assay protocol to measure fecal corticosterone metabolites in repeated samples collected from undisturbed male and female adult Sprague-Dawley rats. This fecal measure provides a non-invasive method to assess changes in corticosterone within a single animal over time, with sufficient temporal acuity to quantify several characteristics of the circadian rhythm: e.g. the nadir, acrophase, and asymmetry (saw-tooth) of the rhythm. Males excreted more immunoreactive fecal corticoids than did females. Across the estrous cycle, females produced more fecal corticoids on proestrus (the day of the preovulatory luteinizing hormone surge) than during estrus or metestrus. These results establish a baseline from which to study environmental, psychological, and physiological disturbances of the circadian corticosterone rhythm within individual rats.
Assuntos
Corticosteroides/análise , Ritmo Circadiano , Fezes/química , Animais , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia Líquida , Corticosterona/metabolismo , Ciclo Estral , Feminino , Masculino , Ratos , Ratos Sprague-Dawley , Sensibilidade e Especificidade , Análise EspectralRESUMO
The secretory response of the primate corpus luteum (CL) to CG after implantation suggests that gonadotropin receptors are not depleted despite increasing CG production and continuous elevated tropic stimulation. Such continuous stimulation is known to cause down-regulation of receptors in other tissues. To determine if CG secretion is intermittent during the initial stages of CL rescue, we assessed the secretory pattern of CG during the periimplantation period by collecting frequent (4/h) blood samples in two studies (for 4 h on 3 separate days between days 8-13, or for 2 separate 13-h sequences between days 10-15 postovulation) in 13 chair-adapted females. Day 0 of gestation was defined as the day of ovulation, as estimated by peak urinary estrone conjugate excretion in females mated on days 9, 11, and 13 of the menstrual cycle. Hormone concentrations were measured by either RIA [irFSH; estradiol and progesterone (P)] or Leydig cell bioassay (bioLH or bioCG). In the first study, 4 of 6 females conceived, and the mean for bioLH was not significantly elevated until days 12-13. In the second study, 5 of 7 females conceived, and the episodic secretory pattern of circulating pituitary bioLH typically observed in cycling females (2.7 +/- 0.3 peaks/13 h) was replaced by a relatively nonpulsatile, but steadily increasing profile during days 12-15 of gestation (1.5 +/- 0.4 peaks/13 h). Although occasional large fluctuations in bioLH/CG and P were noted, the bioLH/P peaks were less congruent than those in nonfertile cycles, and there was no diurnal pattern in the secretion of either hormone. In contrast, irFSH concentrations did not fluctuate and were similar in the two groups of females [2.93 +/- 0.28 vs. 2.34 +/- 1.7 ng/ml (mean +/- SEM)]. These data demonstrate that 1) a steady, gradually increasing secretory pattern of CG is associated with rescue of the CL; 2) the circulating profile of CG during the periimplantation interval is not consistently episodic and does not support the hypothesis that intermittent CG release prevents LH/CG receptor down-regulation in the CL during early pregnancy; 3) increased bioLH/CG levels during conceptive cycles in rhesus monkeys are not detected until days 12-13 after the midcycle bioLH peak; 4) irFSH patterns on pooled aliquots appear to be uninformative with regard to gonadotropin dynamics in early pregnancy; and 5) urinary estrone conjugate measurements provide a practical method for the precise timing of infrequent events, such as implantation, in the laboratory macaque.