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1.
Langmuir ; 35(12): 4270-4277, 2019 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-30840470

RESUMO

We report on the chemical analysis of ultrathin (10 nm) polymer films using the attenuated total reflectance-Fourier transform infrared (ATR-FTIR) technique based on p-polarized infrared light and two types of enhancing substrates, that is, metallic (Au) and dielectric (Si). We selected low-temperature plasma-treated ∼10 nm thick polystyrene films as a test case for demonstrating the capability of the p-polarized ATR-FTIR, whose performance was further compared with the conventional X-ray photoelectron spectroscopy (XPS) techniques. Although ATR-FTIR cannot be used for quantitatively determining elemental compositions in polymers at which XPS excels, it is able to be operated under nonvacuum conditions and allows the study of hydrogen-containing moieties. By correcting the contact condition between the polymer surface and the ATR prism, the relative concentration of the chemical bonds from different samples can be compared. Because ATR-FTIR and XPS provide complementary information on chemical bonds, their combination provides a powerful approach for studying the chemical composition of polymers.

2.
Nanotechnology ; 28(17): 175301, 2017 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-28374684

RESUMO

Thermal scanning probe lithography (t-SPL) is applied to the fabrication of chemical guiding patterns for directed self-assembly (DSA) of block copolymers (BCP). The two key steps of the overall process are the accurate patterning of a poly(phthalaldehyde) resist layer of only 3.5 nm thickness, and the subsequent oxygen-plasma functionalization of an underlying neutral poly(styrene-random-methyl methacrylate) brush layer. We demonstrate that this method allows one to obtain aligned line/space patterns of poly(styrene-block-methyl methacrylate) BCP of 18.5 and 11.7 nm half-pitch. Defect-free alignment has been demonstrated over areas of tens of square micrometres. The main advantages of t-SPL are the absence of proximity effects, which enables the realization of patterns with 10 nm resolution, and its compatibility with standard DSA methods. In the brush activation step by oxygen-plasma exposure, we observe swelling of the brush. This effect is discussed in terms of the chemical reactions occurring in the exposed areas. Our results show that t-SPL can be a suitable method for research activities in the field of DSA, in particular for low-pitch, high-χ BCP to achieve sub-10 nm line/space patterns.

3.
J Chem Phys ; 146(5): 052801, 2017 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-28178847

RESUMO

With the increasing interest in establishing directional etching methods capable of atomic scale resolution for fabricating highly scaled electronic devices, the need for development and characterization of atomic layer etching processes, or generally etch processes with atomic layer precision, is growing. In this work, a flux-controlled cyclic plasma process is used for etching of SiO2 and Si at the Angstrom-level. This is based on steady-state Ar plasma, with periodic, precise injection of a fluorocarbon (FC) precursor (C4F8 and CHF3) and synchronized, plasma-based Ar+ ion bombardment [D. Metzler et al., J. Vac. Sci. Technol., A 32, 020603 (2014) and D. Metzler et al., J. Vac. Sci. Technol., A 34, 01B101 (2016)]. For low energy Ar+ ion bombardment conditions, physical sputter rates are minimized, whereas material can be etched when FC reactants are present at the surface. This cyclic approach offers a large parameter space for process optimization. Etch depth per cycle, removal rates, and self-limitation of removal, along with material dependence of these aspects, were examined as a function of FC surface coverage, ion energy, and etch step length using in situ real time ellipsometry. The deposited FC thickness per cycle is found to have a strong impact on etch depth per cycle of SiO2 and Si but is limited with regard to control over material etching selectivity. Ion energy over the 20-30 eV range strongly impacts material selectivity. The choice of precursor can have a significant impact on the surface chemistry and chemically enhanced etching. CHF3 has a lower FC deposition yield for both SiO2 and Si and also exhibits a strong substrate dependence of FC deposition yield, in contrast to C4F8. The thickness of deposited FC layers using CHF3 is found to be greater for Si than for SiO2. X-ray photoelectron spectroscopy was used to study surface chemistry. When thicker FC films of 11 Å are employed, strong changes of FC film chemistry during a cycle are seen whereas the chemical state of the substrate varies much less. On the other hand, for FC film deposition of 5 Å for each cycle, strong substrate surface chemical changes are seen during an etching cycle. The nature of this cyclic etching with periodic deposition of thin FC films differs significantly from conventional etching with steady-state FC layers since surface conditions change strongly throughout each cycle.

4.
AIDS ; 30(17): 2707-2714, 2016 11 13.
Artigo em Inglês | MEDLINE | ID: mdl-27536979

RESUMO

OBJECTIVES: HIV-2-infected individuals usually initiate antiretroviral therapy (ART) at an advanced age compared with HIV-1 patients, with a potential impact on treatment outcomes. This study aimed to investigate the effect of sex and age on mortality and loss to follow-up (LTFU) among HIV-2-infected individuals initiating ART. METHODS: Analyses were conducted using the database of the International Epidemiological Databases to Evaluate AIDS's collaboration in West Africa. LTFU was considered if the interval between the last visit and the closing date for this analysis was more than 180 days. Probability of death and LTFU were estimated with Kaplan-Meier methods. A Cox regression model was used to identify factors associated with death and LTFU over the first 24 months on ART. RESULTS: A total of 1825 HIV-2-infected individuals, including 60% women were considered for this analysis. The median age, baseline CD4 cell count, and follow-up duration were 45 years [interquartile range (IQR; 38-52)], 185 cells/µl [IQR (95-297)], and 28.8 months [IQR (9.8-58.9)], respectively. Over the first 24 months, the mortality rate was 5.2/100 person-years of observation [95% confidence interval (CI; 4.4-6.1)] and 469 (25.7%) were LTFU. Male sex [hazard ratio (HR) = 1.9; 95% CI (1.4; 2.8)], baseline CD4 cell count less than 100 cell/µl [HR = 4.4 95% CI (1.7; 11.1); ref at least 350 cell/µl], haemoglobin 7.5-10 g/dl [HR = 2.4 95% CI (1.3; 4.4); ref at least 12 g/dl], and BMI less than 18 kg/m [HR = 2.1 95% CI (1.3; 3.4); ref = 18-25 kg/m] were associated with higher mortality over the first 24 months. Similar associations were found for LTFU. CONCLUSION: Mortality and LTFU are high among ART-receiving HIV-2-infected individuals and higher in men than in women. There is a critical need to further determine the causes of poor retention and implement sex-specific solutions that improve outcomes in HIV-2 ART programmes.


Assuntos
Antirretrovirais/uso terapêutico , Terapia Antirretroviral de Alta Atividade , Infecções por HIV/tratamento farmacológico , HIV-2/isolamento & purificação , Adolescente , Adulto , África Ocidental , Fatores Etários , Idoso , Feminino , Infecções por HIV/mortalidade , Infecções por HIV/virologia , Humanos , Masculino , Pessoa de Meia-Idade , Fatores Sexuais , Análise de Sobrevida , Resultado do Tratamento , Adulto Jovem
5.
J Vac Sci Technol A ; 34(4): 040603, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27375342

RESUMO

The authors studied the effect of the temperature and chemical state of the chamber wall on process performance for atomic layer etching of SiO2 using a steady-state Ar plasma, periodic injection of a defined number of C4F8 molecules, and synchronized plasma-based Ar+ ion bombardment. To evaluate these effects, the authors measured the quartz coupling window temperature. The plasma gas phase chemistry was characterized using optical emission spectroscopy. It was found that although the thickness of the polymer film deposited in each cycle is constant, the etching behavior changed, which is likely related to a change in the plasma gas phase chemistry. The authors found that the main gas phase changes occur after C4F8 injection. The C4F8 and the quartz window react and generate SiF and CO. The emission intensity changes with wall surface state and temperature. Therefore, changes in the plasma gas species generation can lead to a shift in etching performance during processing. During initial cycles, minimal etching is observed, while etching gradually increases with cycle number.

6.
Rev. argent. endocrinol. metab ; 52(2): 57-65, jul. 2015. ilus, tab
Artigo em Espanhol | LILACS | ID: biblio-843116

RESUMO

La ginecomastia es la proliferación benigna del tejido glandular mamario del varón, generalmente aparece en ciertos periodos de la vida como la época neonatal, puberal o senil, siendo la expresión de cierto disbalance en la acción de estrógenos y andrógenos en la glándula mamaria. Es poco frecuente durante la prepubertad y se debe investigar exhaustivamente el origen de la misma. Objetivo: evaluar las características clínicas y poder definir la etiología en un grupo de pacientes con ginecomastia prepuberal, Materiales y métodos: es un estudio retrospectivo, descriptivo y multicéntrico. Se recolectaron datos de antecedentes familiares, personales, examen físico, laboratorio, evolución, conducta terapéutica y se determinaron las posibles etiologías. Resultados: Fueron evaluados 53 pacientes con ginecomastia, con edad media de 8,4 años (0,88-13,72 años), se encontró mayor prevalencia en niños mayores de 7 años (79,2 %). La presentación bilateral fue la más frecuente en el 73,5 %, 17 (32 %) presentaron obesidad, siendo en 7 (13,7 %) severa (IMC ≥ 3 SDS). En 34 pacientes (64,1 %) no se encontró la etiología; en 12 pacientes (23,5 %) se constató fuente exógena de estrógeno; 2 pacientes con exceso de aromatasa; 1 con neurofibromatosis tipo I y glíoma del nervio óptico; 1 niño con tumor suprarrenal izquierdo productor de estrógenos y 1 paciente con síndrome de Peutz-Jeghers. Conclusión: La ginecomastia prepuberal es poco común, en esta población el mayor porcentaje fue idiopática o por exposición a estrógenos exógenos, pero es una señal de alarma que obliga a descartar la presencia de un trastorno endocrinológico importante.


Gynecomastia is the benign proliferation of male breast glandular tissue. The occurrence of gynecomastia at prepubertal ages is very uncommon and can be a sign of severe endocrine or systemic disease. The main underlying mechanism for the development of gynecomastia appears to be the imbalance between estrogen and androgen action. Objective: to assess clinical characteristics, etiology and course of prepubertal gynecomastia in a group of patients regularly followed at the endocrinology clinic. We performed a retrospective, descriptive, multicenter study. Materials and methods: data on family history, past history of the disease, physical examination, and clinical course were collected. Results: 53 prepubertal patients were included. Median age at presentation was 8.4 years (0.88-13.72 years). An increased prevalence was observed in children > 7 years (79.2 %). Bilateral gynecomastia was the most common form of presentation, (73.5 %). Seventeen patients (32 %) were obese, 7 (13.7 %) with a BMI above 3 SDS. In 34 patients (64.1 %) the etiology of gynecomastia could not be identified (idiopathic). In 12 patients (23.5 %) estrogen exposure was detected; 2 patients suffered from aromatase excess syndrome, 1 had neurofibromatosis type I and optic glioma, 1 had a feminizing adrenocortical tumor and 1 had Peutz-Jeghers syndrome. Conclusion: Prepubertal gynecomastia is rare. In this cohort of 53 children, the most common etiologies were idiopathic or exogenous estrogens exposure. Although gynecomastia may be due to benign causes, in the majority of patients evaluations should be performed to rule out a severe underlying systemic or endocrine disease.

7.
Biointerphases ; 10(2): 029512, 2015 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-25930012

RESUMO

An atmospheric pressure plasma jet (APPJ) was used to treat polystyrene (PS) films under remote conditions where neither the plume nor visible afterglow interacts with the film surface. Carefully controlled conditions were achieved by mounting the APPJ inside a vacuum chamber interfaced to a UHV surface analysis system. PS was chosen as a model system as it contains neither oxygen nor nitrogen, has been extensively studied, and provides insight into how the aromatic structures widespread in biological systems are modified by atmospheric plasma. These remote treatments cause negligible etching and surface roughening, which is promising for treatment of sensitive materials. The surface chemistry was measured by X-ray photoelectron spectroscopy to evaluate how ambient chemistry, feed gas chemistry, and plasma-ambient interaction impact the formation of specific moieties. A variety of oxidized carbon species and low concentrations of NOx species were measured after APPJ treatment. In the remote conditions used in this work, modifications are not attributed to short-lived species, e.g., O atoms. It was found that O3 does not correlate with modifications, suggesting that other long-lived species such as singlet delta oxygen or NOx are important. Indeed, surface-bound NO3 was observed after treatment, which must originate from gas phase NOx as neither N nor O are found in the pristine film. By varying the ambient and feed gas chemistry to produce O-rich and O-poor conditions, a possible correlation between the oxygen and nitrogen composition was established. When oxygen is present in the feed gas or ambient, high levels of oxidation with low concentrations of NO3 on the surface were observed. For O-poor conditions, NO and NO2 were measured, suggesting that these species contribute to the oxidation process, but are easily oxidized when oxygen is present. That is, surface oxidation limits and competes with surface nitridation. Overall, surface oxidation takes place easily, but nitridation only occurs under specific conditions with the overall nitrogen content never exceeding 3%. Possible mechanisms for these processes are discussed. This work demonstrates the need to control plasma-ambient interactions and indicates a potential to take advantage of plasma-ambient interactions to fine-tune the reactive species output of APP sources, which is required for specialized applications, including polymer surface modifications and plasma medicine.


Assuntos
Pressão Atmosférica , Gases/metabolismo , Gases em Plasma , Poliestirenos/química , Propriedades de Superfície/efeitos dos fármacos , Carbono/análise , Nitratos/análise , Óxido Nítrico/análise , Nitritos/análise , Espectroscopia Fotoeletrônica
8.
Andrology ; 3(1): 59-69, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25598272

RESUMO

All malignant testicular germ cell tumors (TGCT) of adult men are preceded by an in situ stage (CIS) of protracted evolution. The adult CIS is well characterized, but there is debate on the phenotype of infantile CIS, its distinction from delayed maturation of germ cells and prognostic potential. A large series of 43 patients with Disorders of Sex Development (DSD) and dysgenetic testes (90% ranging from neonates to 12 years, mean age 4.7 years), was studied by quantifying dysgenetic features, degree of germ cell abnormalities/atypia (GCA), expression of OCT 3/4 (a pluripotency-undifferentiation marker), germ cell ploidy and evolution to CIS and invasive TGCT. Findings were compared with those of normal testes. The type of gonads present defined three groups of patients: bilateral testes (BT-DSD, n = 21), one testis and one streak gonad (CT-DSD, C for combined, n = 13), and ovarian-testicular combinations (OT-DSD, n = 9). There were 5 boys with infantile CIS, bilateral in 3 (total of 8 infantile CIS) and two patients with adult CIS, bilateral in one (total of 3 adult CIS). Two patients had bilateral seminomas one at 12-17 and the other at 23 years. Histological dysgenesis was significantly higher in CT-DSD (p < 0.05), that had only 1 CIS. The highest frequency of GCA was in BT-DSD (p < 0.05), which coincided with a total of 11CIS + Seminomas. In all patients, aneuploidy was significantly higher (63%) than diploidy (p < 0.02), and GCA were more frequent in aneuploid than in diploid samples (p < 0.02). All CIS and TGCT were OCT 3/4 positive. Finally, there was a significant association between the triad Aneuploidy + GCA + OCT 3/4 positivity and the incidence of CIS (Fisher Exact test p < 0.002, relative risk 7.0). The degree of testicular dysgenesis (derived from abnormal organization of Sertoli cells in fetal testicular cords) is inversely related to the incidence of CIS. Our data demonstrate that the combined use of OCT 3/4 expression, quantification of germ cell abnormalities-atypia and ploidy in dysgenetic testes can satisfactorily identify infantile CIS with high risk of malignant evolution and set it aside from delayed germ cell maturation with lower or nil neoplastic potential.


Assuntos
Biomarcadores Tumorais/genética , Carcinoma in Situ/genética , Disgenesia Gonadal/genética , Seminoma/genética , Desenvolvimento Sexual/genética , Neoplasias Testiculares/genética , Adolescente , Argentina/epidemiologia , Carcinoma in Situ/química , Carcinoma in Situ/epidemiologia , Carcinoma in Situ/patologia , Criança , Pré-Escolar , Feminino , Predisposição Genética para Doença , Testes Genéticos , Disgenesia Gonadal/epidemiologia , Humanos , Incidência , Lactente , Recém-Nascido , Masculino , Fator 3 de Transcrição de Octâmero/análise , Fenótipo , Ploidias , Valor Preditivo dos Testes , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Seminoma/química , Seminoma/epidemiologia , Seminoma/patologia , Neoplasias Testiculares/química , Neoplasias Testiculares/epidemiologia , Neoplasias Testiculares/patologia , Adulto Jovem
9.
J Vet Intern Med ; 29(1): 184-92, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25418027

RESUMO

BACKGROUND: It is unknown if diabetic cats in remission have persistent abnormalities of glucose metabolism and should be considered prediabetic, or have normal glucose tolerance. OBJECTIVE: To characterize glycemic status of diabetic cats in remission and to determine predictors of relapse. ANIMALS: A total of 21 cats in diabetic remission and 28 healthy control cats. METHODS: At a median of 107 days after remission, screening blood glucose concentration was measured on entry to the clinic. After a 24-hour fast in hospital, fasting blood glucose, fructosamine and feline pancreatic lipase concentrations were measured, and 3 hours later, a simplified IV glucose tolerance test (1 g glucose/kg) performed. Twenty cats were monitored for relapse for at least 9 months. RESULTS: Of the 21 cats in remission, 19% (4/21) had impaired fasting glucose concentration and 76% (16/21) had impaired glucose tolerance. Of cats followed up for 9 months after testing, 30% (6/20) had relapsed and required insulin treatment. Fasting blood glucose concentration ≥ 7.5 mmol/L (≥ 135 mg/dL) (odds ratio [OR] = 12.8) and severely impaired glucose tolerance (≥ 5 hours to return to <6.5 mmol/L or <117 mg/dL; OR = 15.2) were significantly associated with relapse. Blood glucose concentration >14 mmol/L; 252 mg/dL at 3 hours was significantly associated with relapse (OR = 10.1). CONCLUSION AND CLINICAL IMPORTANCE: Most cats in diabetic remission have impaired glucose tolerance and a minority have impaired fasting glucose concentration and should be considered prediabetic. More severe glucose intolerance and impaired fasting glucose concentration are predictors of relapse. Ongoing glucose monitoring of diabetic cats in remission is recommended.


Assuntos
Glicemia/fisiologia , Doenças do Gato/sangue , Diabetes Mellitus/veterinária , Corticosteroides/efeitos adversos , Envelhecimento , Animais , Gatos , Diabetes Mellitus/sangue , Feminino , Intolerância à Glucose , Lipase/sangue , Lipase/metabolismo , Masculino , Pâncreas/enzimologia , Pancreatite/sangue , Pancreatite/veterinária , Recidiva , Remissão Espontânea
10.
Aust Vet J ; 91(5): 171-8, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23614511

RESUMO

OBJECTIVES: To investigate in vitro susceptibilities of canine and feline Escherichia coli and canine Pseudomonas spp. isolates to ticarcillin and ticarcillin-clavulanic acid (T/C). DESIGN: In vitro susceptibility testing of bacterial isolates collected from infections. METHODS: We tested 148 (83 canine and 65 feline) E. coli and 61 canine Pseudomonas spp. isolates for susceptibility to T/C using both disc diffusion and Epsilometer tests (E-tests). Additionally, susceptibilities of 96 E. coli and 23 canine Pseudomonas spp. isolates were tested via disc diffusion to ticarcillin alone. RESULTS: Of the E. coli isolates obtained from canine and feline urine, 92% by disc diffusion and 91% by E-tests were susceptible to T/C. Of the canine Pseudomonas isolates, 90% by disc diffusion and 82% by E-tests were susceptible to T/C. Of the Pseudomonas spp. isolates from the canine ear canal or tympanic bullae, 12% of isolates tested via disc diffusion and 23% via E-tests were found to be resistant to T/C. The 50% minimum inhibitory concentration of T/C for all feline E. coli isolates was significantly lower than that for all canine E. coli isolates (P = 0.0031). The addition of clavulanic acid significantly increased the efficacy of ticarcillin against E. coli (P< 0.0001), but had negligible effect against canine Pseudomonas spp. isolates. CONCLUSION: Ticarcillin-clavulanic acid has reasonable in vitro efficacy against canine and feline E. coli, and canine Pseudomonas spp. isolates. However, decisions to use this drug therapeutically must be made on prudent considerations to minimise selection for bacterial resistance.


Assuntos
Antibacterianos/farmacologia , Escherichia coli/efeitos dos fármacos , Testes de Sensibilidade Microbiana/veterinária , Pseudomonas/efeitos dos fármacos , Ticarcilina/farmacologia , Animais , Doenças do Gato/tratamento farmacológico , Doenças do Gato/microbiologia , Gatos , Ácidos Clavulânicos/farmacologia , Contagem de Colônia Microbiana/veterinária , Doenças do Cão/tratamento farmacológico , Doenças do Cão/microbiologia , Cães , Relação Dose-Resposta a Droga , Farmacorresistência Bacteriana , Testes de Sensibilidade Microbiana/métodos , Resultado do Tratamento
11.
Andrology ; 1(1): 3-16, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23258624

RESUMO

Normal testicular physiology results from the integrated function of the tubular and interstitial compartments. Serum markers of interstitial tissue function are testosterone and insulin-like factor 3 (INSL3), whereas tubular function can be assessed by sperm count, morphology and motility, and serum anti-Müllerian hormone (AMH) and inhibin B. The classical definition of male hypogonadism refers to testicular failure associated with androgen deficiency, without considering potential deficiencies in germ and Sertoli cells. Furthermore, the classical definition does not consider the fact that low basal serum testosterone cannot be equated to hypogonadism in childhood, because Leydig cells are normally quiescent. A broader clinical definition of hypogonadism that could be applied to male patients in different periods of life requires a comprehensive consideration of the physiology of the hypothalamic-pituitary-testicular axis and its disturbances along development. Here we propose an extended classification of male hypogonadism based on the pathophysiology of the hypothalamic-pituitary-testicular axis in different periods of life. The clinical and biochemical features of male hypogonadism vary according to the following: (i) the level of the hypothalamic-pituitary-testicular axis primarily affected: central, primary or combined; (ii) the testicular cell population initially impaired: whole testis dysfunction or dissociated testicular dysfunction, and: (iii) the period of life when the gonadal function begins to fail: foetal-onset or postnatal-onset. The evaluation of basal testicular function in infancy and childhood relies mainly on the assessment of Sertoli cell markers (AMH and inhibin B). Hypergonadotropism should not be considered a sine qua non condition for the diagnosis of primary hypogonadism in childhood. Finally, the lack of elevation of gonadotropins in adolescents or adults with primary gonadal failure is indicative of a combined hypogonadism involving the gonads and the hypothalamic-pituitary axis.


Assuntos
Eunuquismo/classificação , Sistema Hipotálamo-Hipofisário/crescimento & desenvolvimento , Terminologia como Assunto , Testículo/crescimento & desenvolvimento , Adolescente , Adulto , Idade de Início , Envelhecimento , Hormônio Antimülleriano/metabolismo , Biomarcadores/metabolismo , Criança , Pré-Escolar , Técnicas de Diagnóstico Endócrino , Eunuquismo/diagnóstico , Eunuquismo/epidemiologia , Eunuquismo/metabolismo , Eunuquismo/fisiopatologia , Humanos , Sistema Hipotálamo-Hipofisário/metabolismo , Sistema Hipotálamo-Hipofisário/fisiopatologia , Lactente , Recém-Nascido , Inibinas/metabolismo , Masculino , Valor Preditivo dos Testes , Fatores de Risco , Análise do Sêmen , Desenvolvimento Sexual , Espermatogênese , Testículo/metabolismo , Testículo/fisiopatologia , Testosterona/metabolismo , Adulto Jovem
12.
Int J Androl ; 34(5 Pt 2): e487-98, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21831236

RESUMO

Male patients with an extra sex chromosome or autosome are expected to present primary hypogonadism at puberty owing to meiotic germ-cell failure. Scarce information is available on trisomy 21, a frequent autosomal aneuploidy. Our objective was to assess whether trisomy 21 presents with pubertal-onset, germ-cell specific, primary hypogonadism in males, or whether the hypogonadism is established earlier and affects other testicular cell populations. We assessed the functional status of the pituitary-testicular axis, especially Sertoli cell function, in 117 boys with trisomy 21 (ages: 2months-20year). To compare with an adequate control population, we established reference levels for serum anti-Müllerian hormone (AMH) in 421 normal males, from birth to adulthood, using a recently developed ultrasensitive assay. In trisomy 21, AMH was lower than normal, indicating Sertoli cell dysfunction, from early infancy, independently of the existence of cryptorchidism. The overall prevalence rate of AMH below the 3rd percentile was 64.3% in infants with trisomy 21. Follicle-stimulating hormone was elevated in patients <6months and after pubertal onset. Testosterone was within the normal range, but luteinizing hormone was elevated in most patients <6months and after pubertal onset, indicating a mild Leydig cell dysfunction. We conclude that in trisomy 21, primary hypogonadism involves a combined dysfunction of Sertoli and Leydig cells, which can be observed independently of cryptorchidism soon after birth, thus prompting the search for new hypotheses to explain the pathophysiology of gonadal dysfunction in autosomal trisomy.


Assuntos
Hormônio Antimülleriano/sangue , Síndrome de Down/fisiopatologia , Hipogonadismo/fisiopatologia , Adolescente , Adulto , Criança , Pré-Escolar , Síndrome de Down/complicações , Hormônio Foliculoestimulante/sangue , Humanos , Hipogonadismo/sangue , Hipogonadismo/etiologia , Lactente , Recém-Nascido , Células Intersticiais do Testículo/fisiologia , Hormônio Luteinizante/sangue , Masculino , Tamanho do Órgão , Células de Sertoli/fisiologia , Testículo/anatomia & histologia , Testosterona/sangue
13.
N Engl J Med ; 365(1): 32-43, 2011 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-21732835

RESUMO

BACKGROUND: Nesiritide is approved in the United States for early relief of dyspnea in patients with acute heart failure. Previous meta-analyses have raised questions regarding renal toxicity and the mortality associated with this agent. METHODS: We randomly assigned 7141 patients who were hospitalized with acute heart failure to receive either nesiritide or placebo for 24 to 168 hours in addition to standard care. Coprimary end points were the change in dyspnea at 6 and 24 hours, as measured on a 7-point Likert scale, and the composite end point of rehospitalization for heart failure or death within 30 days. RESULTS: Patients randomly assigned to nesiritide, as compared with those assigned to placebo, more frequently reported markedly or moderately improved dyspnea at 6 hours (44.5% vs. 42.1%, P=0.03) and 24 hours (68.2% vs. 66.1%, P=0.007), but the prespecified level for significance (P≤0.005 for both assessments or P≤0.0025 for either) was not met. The rate of rehospitalization for heart failure or death from any cause within 30 days was 9.4% in the nesiritide group versus 10.1% in the placebo group (absolute difference, -0.7 percentage points; 95% confidence interval [CI], -2.1 to 0.7; P=0.31). There were no significant differences in rates of death from any cause at 30 days (3.6% with nesiritide vs. 4.0% with placebo; absolute difference, -0.4 percentage points; 95% CI, -1.3 to 0.5) or rates of worsening renal function, defined by more than a 25% decrease in the estimated glomerular filtration rate (31.4% vs. 29.5%; odds ratio, 1.09; 95% CI, 0.98 to 1.21; P=0.11). CONCLUSIONS: Nesiritide was not associated with an increase or a decrease in the rate of death and rehospitalization and had a small, nonsignificant effect on dyspnea when used in combination with other therapies. It was not associated with a worsening of renal function, but it was associated with an increase in rates of hypotension. On the basis of these results, nesiritide cannot be recommended for routine use in the broad population of patients with acute heart failure. (Funded by Scios; ClinicalTrials.gov number, NCT00475852.).


Assuntos
Dispneia/tratamento farmacológico , Insuficiência Cardíaca/tratamento farmacológico , Natriuréticos/uso terapêutico , Peptídeo Natriurético Encefálico/uso terapêutico , Readmissão do Paciente/estatística & dados numéricos , Doença Aguda , Idoso , Método Duplo-Cego , Dispneia/etiologia , Feminino , Insuficiência Cardíaca/complicações , Insuficiência Cardíaca/mortalidade , Humanos , Hipotensão/induzido quimicamente , Análise de Intenção de Tratamento , Nefropatias/etiologia , Masculino , Pessoa de Meia-Idade , Natriuréticos/efeitos adversos , Peptídeo Natriurético Encefálico/efeitos adversos , Recidiva
14.
Vet Microbiol ; 147(1-2): 113-8, 2011 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-20619975

RESUMO

Rapidly growing mycobacteria (RGM) cause infections in cats and dogs which require prolonged antibacterial medication for resolution. In Australia, pathogens from the Mycobacterium fortuitum and Mycobacterium smegmatis clusters are responsible for most of the RGM infections in cats and dogs. As fluoroquinolones are often recommended for treating such infections, 14 M. fortuitum isolates, 51 isolates from the M. smegmatis cluster and 2 M. mageritense isolates, collected from feline and canine patients, underwent susceptibility testing to the second generation fluoroquinolones ciprofloxacin and enrofloxacin and the newer generation fluoroquinolone moxifloxacin. Using microbroth dilution, the MIC(90) of ciprofloxacin, enrofloxacin, and moxifloxacin that inhibited growth of M. fortuitum isolates were 0.500, 0.250 and 0.063 µg/mL respectively. For the M. smegmatis cluster isolates the corresponding MIC(90) was 0.500, 0.250 and 0.125 µg/mL respectively. E-test results showed similar trends but MICs were lower than those determined by microbroth dilution. Additionally, moxifloxacin was administered to 10 clinically normal cats (50mg per cat, once daily for 4 days). The plasma moxifloxacin concentration 2h after the last dose was determined by liquid chromatography as 2.2 ± 0.6 µg/mL. The plasma concentration at 2h:MIC(90) ratios for moxifloxacin for M. fortuitum and M. smegmatis cluster was 34.9 and 17.6 respectively which exceeded the recommended threshold of 10, indicating that moxifloxacin has good theoretical efficacy for treatment of those M. fortuitum and M. smegmatis infections in cats and dogs that have become refractory to other antibacterial drug classes.


Assuntos
Antibacterianos/farmacologia , Fluoroquinolonas/farmacologia , Mycobacterium/efeitos dos fármacos , Animais , Antibacterianos/efeitos adversos , Antibacterianos/sangue , Antibacterianos/farmacocinética , Austrália , Compostos Aza/efeitos adversos , Compostos Aza/sangue , Compostos Aza/farmacocinética , Gatos , Ciprofloxacina/farmacologia , Diarreia/induzido quimicamente , Diarreia/veterinária , Cães , Enrofloxacina , Feminino , Fluoroquinolonas/efeitos adversos , Fluoroquinolonas/sangue , Fluoroquinolonas/farmacocinética , Masculino , Testes de Sensibilidade Microbiana/veterinária , Moxifloxacina , Mycobacterium/isolamento & purificação , Quinolinas/efeitos adversos , Quinolinas/sangue , Quinolinas/farmacocinética
15.
Rev. argent. endocrinol. metab ; 47(4): 29-39, oct.-dic. 2010. graf, tab
Artigo em Espanhol | LILACS | ID: lil-641981

RESUMO

El Síndrome de Klinefelter (SK) es la anormalidad cromosómica más frecuente en los varones, con una prevalencia estimada de 1:600 recién nacidos. El objetivo de este trabajo fue establecer las distintas características de presentación del SK a distintas edades, incluyendo signos y síntomas clínicos, parámetros de laboratorio y otros exámenes complementarios. La franja etaria más frecuente de diagnóstico de SK fue entre los 11 y 20 años (46,8%). En 4 casos el diagnóstico fue prenatal. Los motivos de consulta más frecuentes en forma global fueron la presencia de testículos pequeños, infertilidad y criptorquidia. El cariotipo más prevalente fue el clásico 47,XXY (83,7%), seguido del mosaico 47,XXY/46,XY (7,1%). El promedio de talla de nuestros pacientes prepuberales no mostró diferencia con la población general. Por otro lado, los pacientes puberales presentaron un promedio de talla significativamente más alto, hallándose alrededor de 1 SDS. Hubo correlación entre la edad y el SDS de talla. La media de talla de los adultos fue 178,8 ± 9,0 cm; se observó un 62,5% de sobrepeso/obesidad (IMC ≥ 25,0 kg/m²). El 50% de nuestros pacientes con SK menores de 18 años presentaron trastornos neurocognitivos. El hallazgo clínico más frecuente entre los pacientes prepuberales fue la criptorquidia. En los puberales las consultas y hallazgos clínicos más frecuentes fueron: testículos pequeños, criptorquidia y ginecomastia. Todos nuestros pacientes en estadio de Tanner igual o mayor de III presentaron testículos más pequeños para su grado de desarrollo. Los valores de FSH y LH fueron normales en los pacientes prepuberales y comenzaron a aumentar en la pubertad. Los adultos consultaron más frecuentemente por hipotrofia testicular, infertilidad y en menor grado ginecomastia. Todos los pacientes presentaron testículos hipotróficos, con una mediana de volumen testicular de 3,5 (1-8) ml. El 56,4% presentaron función sexual normal; el resto tuvo algún tipo de disfunción sexual. La testosterona total (TT) fue normal en 45% de los pacientes, con descenso consistente con la edad, donde todos los pacientes mayores de 40 años presentaron TT subnormal. El 10,7% de los pacientes que efectuaron espermograma tuvo oligospermia severa, el resto presentó azoospermia. La densitometría ósea fue anormal en el 46,4% de los adultos estudiados. Sin embargo, no hubo diferencias significativas en la prevalencia de osteopenia y osteoporosis entre los pacientes con TT normal o subnormal.


Klinefelter syndrome (KS) is the most common chromosomal aberration among men, with an estimated prevalence of 1:600 newborns. It is an X chromosome polysomy, with X disomy being the most common variant (47,XXY). The aim of this study was to establish the characteristics of KS presentation at different ages, including signs and symptoms, laboratory parameters and other diagnostic tests. The diagnosis of KS was more frequent in the age group between 11 and 20 years (46.8%). Most of the patients (83.7%) showed the classic 47,XXY karyotype and 7.1% showed a 47,XXY/46,XY mosaicism. While mean prepubertal height was not different from the control population, it was significantly higher at puberty. Patients consulted most frequently for small testes, infertility and cryptorchidism. In four cases the diagnosis was prenatal. 50% of our patients younger than 18 years presented neurocognitive disorders. The more frequent clinical findings were cryptorchidism in prepubertal patients; small testes, cryptorchidism and gynecomastia in pubertal patients. All our patients in Tanner stage III or more presented small testes. FSH and LH levels were normal in prepubertal patients and increased abnormally at puberty. On the other hand, most adults consulted for small testes, infertility and gynecomastia. 43.6% of patients had decreased libido, sexual and/or ejaculatory dysfunction. In adults average height (178.8 ± 9.0 cm) and weight (83.6 ± 21.0 kg), were higher than in the normal population, however 8 patients (19%) had a height less tan 170 cm. There was 62.5% of overweight / obesity (BMI ≥ 25.0 kg/m²) in the whole group of adult patients. 35.2% had eunuchoid proportions. All patients had testicular hypotrophc, with a median testicular volume of 3.5 ml (range 1-8 ml). Total testosterone (TT) levels were normal in 45% of adult patients, showing significant correlation with age. All patients aged 40 or more years had subnormal TT levels. In patients who underwent semen analysis, severe oligospermia and azoospermia were found in 10.7% and 89.3% respectively. Bone mineral densitometry showed low bone mass in 46.4% of cases. No significant differences in the prevalence of osteopenia and osteoporosis were observed among patients with normal or subnormal TT.


Assuntos
Humanos , Masculino , Recém-Nascido , Lactente , Pré-Escolar , Criança , Adolescente , Adulto , Pessoa de Meia-Idade , Síndrome de Klinefelter/etiologia , Síndrome de Klinefelter/fisiopatologia , Antropometria , Cariótipo , Síndrome de Klinefelter/diagnóstico
16.
Aust Vet J ; 86(4): 147-52, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18363989

RESUMO

OBJECTIVES AND DESIGN: 1) A prospective study to determine in vitro concentrations for a range of fluoroquinolones, gentamicin and amoxycillin-clavulanate required to inhibit growth of recently collected, feline and canine Escherichia coli and canine Staphylococcus intermedius isolates. 2) A comparative retrospective study to compare the minimum inhibitory concentrations (MICs) of ciprofloxacin, enrofloxacin and amoxycillin-clavulanate for archived canine E coli and S intermedius isolates collected ten to twenty years earlier, with those for recently collected isolates. PROCEDURE: Susceptibility was assessed using disk diffusion, agar dilution susceptibility testing and Epsilometer tests (E-tests) for both recently collected and archived isolates. RESULTS: All feline E coli isolates and recently collected canine S intermedius isolates were susceptible to all fluoroquinolones. There was a statistically significant increase in the MIC range of ciprofloxacin and enrofloxacin for recently collected E coli, and in the MIC range of amoxycillin-clavulanate for recently collected S intermedius isolates compared to archived isolates. Twelve of 59 recently collected canine E coli isolates were resistant to both ciprofloxacin and enrofloxacin. Resistant canine E coli isolates were associated with complicating host or infection site factors. CONCLUSION: This is the first report comparing the MICs for all veterinary fluoroquinolones currently available in Australia for a representative sample of canine and feline E coli and canine S intermedius isolates. Importantly, this study identified 12 of 59 canine E coli isolates resistant to fluoroquinolones and identified the development of low level resistance in canine E coli to ciprofloxacin and enrofloxacin and canine S intermedius to amoxycillin-clavulanate.


Assuntos
Anti-Infecciosos/farmacologia , Doenças do Gato/tratamento farmacológico , Doenças do Cão/tratamento farmacológico , Escherichia coli/efeitos dos fármacos , Fluoroquinolonas/farmacologia , Staphylococcus/efeitos dos fármacos , Animais , Anti-Infecciosos/uso terapêutico , Doenças do Gato/epidemiologia , Doenças do Gato/microbiologia , Gatos , Doenças do Cão/epidemiologia , Doenças do Cão/microbiologia , Cães , Farmacorresistência Bacteriana , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/veterinária , Fluoroquinolonas/uso terapêutico , Testes de Sensibilidade Microbiana/veterinária , New South Wales/epidemiologia , Estudos Prospectivos , Estudos Retrospectivos , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/veterinária , Staphylococcus/isolamento & purificação
17.
Mol Cell Endocrinol ; 260-262: 197-204, 2007 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-17084021

RESUMO

FSH is synthesized and secreted in multiple molecular forms with different oligosaccharide structures which are needed for full expression of biological activity. GnRH and sex steroids modulate oligosaccharide structure and composition. In the present study we have assessed the carbohydrate complexity and proportion of circulating FSH isoforms during puberty, aging and after androgen administration to pubertal anorchid boys. Preparative isoelectrofocusing and lectin chromatography were used to isolate FSH isoforms on the basis of charge and internal carbohydrate complexity. Differences in sialic acid content and a progressive increase of isoforms bearing highly branched oligosaccharides were found during puberty. Less acidic, more bioactive FSH isoforms, secreted at mid-puberty may modulate important maturational events in the Sertoli cell population. Androgen administration to pubertal anorchid boys favoured the secretion of this type of isoforms. In adult men, the predominance of FSH isoforms bearing complex type oligosaccharides remained unchanged until very advanced age. These results show that the predominance of FSH isoforms bearing fully processed oligosaccharides in circulation may contribute to the development and maintenance of seminiferous epithelium function in men.


Assuntos
Carboidratos/química , Concanavalina A/metabolismo , Hormônio Foliculoestimulante/sangue , Isoformas de Proteínas/sangue , Adolescente , Adulto , Idoso , Envelhecimento/sangue , Criança , Humanos , Concentração de Íons de Hidrogênio , Focalização Isoelétrica , Hormônio Luteinizante/sangue , Masculino , Pessoa de Meia-Idade , Puberdade/sangue , Testículo/anormalidades , Testosterona/sangue
18.
Sex Dev ; 1(4): 222-9, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-18391533

RESUMO

We assessed the predictive value of anatomical findings and karyotype for establishing a diagnostic orientation in patients with disorders of sex development (DSD). We performed a retrospective chart analysis of 228 patients, grouped into 4 categories: 46,XX DSD, non-dysgenetic testicular DSD, dysgenetic testicular DSD and ovotesticular DSD. Degree of virilisation, presence of vagina, presence of palpable gonads, size of gonads and a plain karyotype was available for all cases. 46,XX DSD due to congenital adrenal hyperplasia counted for 59.2% of the cases, non-dysgenetic testicular DSD for 13.6%, dysgenetic testicular DSD for 21.5% and ovotesticular DSD for 5.7%. Excluding congenital adrenal hyperplasia (CAH), a karyotype with at least one 46,XX cell line had a high diagnostic efficiency for ovotesticular DSD. In these patients, anatomical findings were not as useful to predict the gonadal phenotype. The existence of a 45,X cell line predicted with very high efficiency dysgenetic testicular DSD. Genital palpation was only partially helpful to predict the existence of testicular tissue. Non-dysgenetic testicular DSD could be ruled out with high efficiency in patients with an abnormal karyotype. Anatomical findings were helpful in 46,XY patients: palpated masses predicted non-dysgenetic testes with high accuracy. In all cases assessment of gonadal volume was less useful.


Assuntos
Transtornos do Desenvolvimento Sexual/diagnóstico , Transtornos do Desenvolvimento Sexual/genética , Hiperplasia Suprarrenal Congênita/complicações , Cromossomos Humanos Y/genética , Transtornos do Desenvolvimento Sexual/etiologia , Feminino , Disgenesia Gonadal 46 XX/diagnóstico , Disgenesia Gonadal 46 XX/etiologia , Disgenesia Gonadal 46 XX/genética , Disgenesia Gonadal 46 XY/diagnóstico , Disgenesia Gonadal 46 XY/etiologia , Disgenesia Gonadal 46 XY/genética , Humanos , Recém-Nascido , Cariotipagem/métodos , Masculino , Ovário/metabolismo , Ovário/patologia , Testículo/metabolismo , Testículo/patologia
20.
J Interv Card Electrophysiol ; 17(1): 65-72, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17235681

RESUMO

INTRODUCTION: Implantable cardioverter defibrillators (ICDs) are effective at reducing mortality in patients at high risk for sudden cardiac death (SCD) but can cause psychological distress and reduce quality of life (QOL). The full benefits of ICDs can only be achieved when the patient's QOL and psychological status are maintained. We examined psychological status and QOL post ICD implantation; the relationship of psychological status to QOL; the relationship of time since implantation to psychological status and QOL; and the relationship of time since ICD implantation and age of patient to these variables. METHODS AND RESULTS: A cross-sectional self-administered assessment of QOL, depression, anxiety, demographic characteristics and cardiovascular health history of patients (n = 48) who had received ICDs within the past 10 years at an urban hospital. Patients who had ICDs for longer experienced worse depression and QOL. Patients who were younger had worse depression, anxiety, and QOL. The combination of anxiety, depression, age, and time since ICD implant significantly predicted overall QOL and the psychosocial and physical dimensions of QOL explaining 55.5, 54, and 34.9% of the variance, respectively. CONCLUSION: Younger ICD patients are at highest risk for psychological distress and poor QOL. Longitudinal research would facilitate determination of the trajectory of changes in psychological status and QOL over the duration of the ICD experience.


Assuntos
Ansiedade/epidemiologia , Desfibriladores Implantáveis/psicologia , Desfibriladores Implantáveis/estatística & dados numéricos , Depressão/epidemiologia , Qualidade de Vida , Medição de Risco/métodos , Perfil de Impacto da Doença , Adulto , Idoso , Idoso de 80 Anos ou mais , Ansiedade/psicologia , Comorbidade , Depressão/psicologia , Humanos , Incidência , Maryland/epidemiologia , Pessoa de Meia-Idade , Psicologia/estatística & dados numéricos , Fatores de Risco
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