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1.
JAMA ; 284(23): 2997-8, 2000 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-11122584
6.
Genet Med ; 2(4): 249-54, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11252710

RESUMO

The International Olympic Committee (IOC) officially mandated gender verification for female athletes beginning in 1968 and continuing through 1998. The rationale was to prevent masquerading males and women with "unfair, male-like" physical advantage from competing in female-only events. Visual observation and gynecological examination had been tried on a trial basis for two years at some competitions leading up to the 1968 Olympic Games, but these invasive and demeaning processes were jettisoned in favor of laboratory-based genetic tests. Sex chromatin and more recently DNA analyses for Y-specific male material were then required of all female athletes immediately preceding IOC-sanctioned sporting events, and many other international and national competitions following the IOC model. On-site gender verification has since been found to be highly discriminatory, and the cause of emotional trauma and social stigmatization for many females with problems of intersex who have been screened out from competition. Despite compelling evidence for the lack of scientific merit for chromosome-based screening for gender, as well as its functional and ethical inconsistencies, the IOC persisted in its policy for 30 years. The coauthors of this manuscript have worked with some success to rescind this policy through educating athletes and sports governors regarding the psychological and physical nature of sexual differentiation, and the inequities of genetic sex testing. In 1990, the International Amateur Athletics Federation (IAAF) called for abandonment of required genetic screening of women athletes, and by 1992 had adopted a fairer, medically justifiable model for preventing only male "impostors" in international track and field. At the recent recommendation of the IOC Athletes Commission, the Executive Board of the IOC has finally recognized the medical and functional inconsistencies and undue costs of chromosome-based methods. In 1999, the IOC ratified the abandonment of on-site genetic screening of females at the next Olympic Games in Australia. This article reviews the history and rationales for fairness in female-only sports that have led to the rise and fall of on-site, chromosome-based gender verification at international sporting events.


Assuntos
Proteínas Nucleares , Análise para Determinação do Sexo/história , Esportes/história , Fatores de Transcrição , Cromatina , Cromossomos , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/história , Ética Médica/história , Feminino , História do Século XX , Humanos , Masculino , Fatores Sexuais , Proteína da Região Y Determinante do Sexo , Esportes/legislação & jurisprudência
7.
J Clin Endocrinol Metab ; 84(12): 4501-9, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10599709

RESUMO

X-linked adrenal hypoplasia congenita (AHC) is a disorder associated with primary adrenal insufficiency and hypogonadotropic hypogonadism (HH). The gene responsible for X-linked AHC, DAX1, encodes a member of the nuclear hormone receptor superfamily. We studied an extended kindred with AHC and HH in which two males (the proband and his nephew) were affected with a nucleotide deletion (501delA). The proband's mother, sister, and niece were heterozygous for this frameshift mutation. At age 27 yr, after 7 yr of low dose hCG therapy, the proband underwent a testicular biopsy revealing rare spermatogonia and Leydig cell hyperplasia. Despite steadily progressive doses of hCG and Pergonal administered over a 3-yr period, the proband remained azoospermic. The proband's mother, sister (obligate carrier), and niece all had a history of delayed puberty, with menarche occurring at ages 17-18 yr. Baseline patterns of pulsatile gonadotropin secretion and gonadotropin responsiveness to exogenous pulsatile GnRH were examined in the affected males. LH, FSH, and free alpha-subunit were determined during 12.5-24 h of frequent blood sampling (every 10 min). Both patients then received pulsatile GnRH (25 ng/kg) sc every 2 h for 6-7 days. Gonadotropin responses to a single GnRH pulse iv were monitored daily to assess the pituitary responsiveness to exogenous GnRH. In the proband, FSH and LH levels demonstrated a subtle, but significant, response to GnRH over the week of pulsatile GnRH therapy. Free alpha-subunit levels demonstrated an erratic pattern of secretion at baseline and no significant response to pulsatile GnRH. We conclude that 1) affected males with AHC/HH may have an intrinsic defect in spermatogenesis that is not responsive to gonadotropin therapy; 2) female carriers of DAX1 mutations may express the phenotype of delayed puberty; and 3) although affected individuals display minimal responses to pulsatile GnRH, as observed in other AHC kindreds, subtle differences in gonadotropin patterns may nevertheless exist between affected individuals within a kindred.


Assuntos
Insuficiência Adrenal/genética , Proteínas de Ligação a DNA/genética , Mutação , Fenótipo , Receptores do Ácido Retinoico/genética , Proteínas Repressoras , Fatores de Transcrição/genética , Cromossomo X , Adolescente , Insuficiência Adrenal/patologia , Insuficiência Adrenal/fisiopatologia , Receptor Nuclear Órfão DAX-1 , Feminino , Hormônio Foliculoestimulante/metabolismo , Ligação Genética , Hormônio Liberador de Gonadotropina/administração & dosagem , Hormônio Liberador de Gonadotropina/uso terapêutico , Humanos , Hormônio Luteinizante/metabolismo , Masculino , Linhagem , Periodicidade , Puberdade Tardia/genética , Espermatogênese , Testículo/patologia , Testosterona/sangue
8.
JAMA ; 282(20): 1913-4; author reply 1915-6, 1999 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-10580447
9.
J Pediatr ; 135(3): 327-31, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10484798

RESUMO

Two kindreds with familial medullary thyroid carcinoma (MTC) are described in which affected family members had variable clinical and pathologic manifestations. Genetic testing in 2 children from one kindred revealed a mutation in exon 10, codon 618 (TGC to AGC) in the extracellular cysteine-rich region of the RET gene. In this kindred an 11-year-old had microscopic evidence of MTC; however, a 17-year-old had no evidence of pathology on thyroidectomy. In a second kindred a rare mutation in exon 14, codon 804 (GTG to TTG) of the intracellular tyrosine kinase region of the RET gene was detected. In this kindred MTC has occurred in the 4th to 5th decades of life, with a clinical spectrum in mutation-positive family members ranging from no disease and C-cell hyperplasia to carcinoma with lymph node metastasis; a 7-year-old with the mutation and a normal response to provocative testing was also identified. Management recommendations in children from families with clearly defined familial MTC may be individualized to reflect emerging genotype-phenotype correlations.


Assuntos
Carcinoma Medular/diagnóstico , Carcinoma Medular/genética , Mutação em Linhagem Germinativa/genética , Neoplasias da Glândula Tireoide/diagnóstico , Neoplasias da Glândula Tireoide/genética , Adolescente , Adulto , Carcinoma Medular/cirurgia , Criança , Análise Mutacional de DNA , Feminino , Testes Genéticos/métodos , Genótipo , Humanos , Pessoa de Meia-Idade , Linhagem , Fenótipo , Neoplasias da Glândula Tireoide/cirurgia , Tireoidectomia
10.
Transfusion ; 38(9): 891-5, 1998 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9738632

RESUMO

BACKGROUND: Controversy exists concerning whether the costs and potential risks outweigh the potential benefits of "crossover" use in the general blood supply of unutilized blood that was donated for autologous transfusion. STUDY DESIGN AND METHODS: Published articles and reports were identified through systematic search of MEDLINE and review of references cited in previously identified articles, textbooks, and reports. Consultation was made with experts in blood donation and transfusion. Additional peer review was received from the American Medical Association (AMA) Council on Scientific Affairs RESULTS: Concern over infectious disease transmission has led to increased interest in and support for autologous transfusion for individuals having planned surgeries. Different requirements exist for collection, labeling, and screening of blood to be used for autologous versus allogeneic transfusions; therefore, procedures for diverting autologous blood donations to the general blood supply involve considerable expense. Several cost-effectiveness studies of autologous blood donation and transfusion conclude that currently this "crossover" appears to be an expensive procedure yielding little increased benefit from a societal perspective. CONCLUSIONS: The recommendations in this report were adopted as AMA Policy at the AMA Annual Meeting in June 1997. The AMA does not encourage blood collection programs to "cross over" units donated for autologous use to the allogeneic blood supply. Practice guidelines are needed, and should be utilized to ensure parsimony in the use of autologous blood donations and transfusions.


Assuntos
Doadores de Sangue , Transfusão de Sangue Autóloga , Transfusão de Sangue/economia , Transfusão de Sangue Autóloga/economia , Análise Custo-Benefício , Humanos , Infecções/transmissão , MEDLINE
11.
Am J Hum Genet ; 62(4): 855-64, 1998 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9529340

RESUMO

The DAX1 protein is an orphan nuclear hormone receptor based on sequence similarity in the putative ligand-binding domain (LBD). DAX1 mutations result in X-linked adrenal hypoplasia congenita (AHC). Our objective was to identify DAX1 mutations in a series of families, to determine the types of mutations resulting in AHC and to locate single-amino-acid changes in a DAX1 structural model. The 14 new mutations identified among our 17 families with AHC brought the total number of families with AHC to 48 and the number of reported mutations to 42; 1 family showed gonadal mosaicism. These mutations included 23 frameshift, 12 nonsense, and six missense mutations and one single-codon deletion. We mapped the seven single-amino-acid changes to a homology model constructed by use of the three-dimensional crystal structures of the thyroid-hormone receptor and retinoid X receptor alpha. All single-amino-acid changes mapped to the C-terminal half of the DAX1 protein, in the conserved hydrophobic core of the putative LBD, and none affected residues expected to interact directly with a ligand. We conclude that most genetic alterations in DAX1 are frameshift or nonsense mutations and speculate that the codon deletion and missense mutations give insight into the structure and function of DAX1.


Assuntos
Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/genética , Mutação , Receptores do Ácido Retinoico/química , Receptores do Ácido Retinoico/genética , Proteínas Repressoras , Fatores de Transcrição/química , Fatores de Transcrição/genética , Cromossomo X , Glândulas Suprarrenais/anormalidades , Sequência de Aminoácidos , Receptor Nuclear Órfão DAX-1 , Ligação Genética , Humanos , Hipogonadismo/genética , Dados de Sequência Molecular , Análise de Sequência , Relação Estrutura-Atividade
12.
Infect Control Hosp Epidemiol ; 19(5): 348-53, 1998 May.
Artigo em Inglês | MEDLINE | ID: mdl-9613698

RESUMO

OBJECTIVE: In June 1996, a resolution was introduced to the House of Delegates of the American Medical Association (AMA) asking the AMA to advocate that healthcare workers be given the informed option of receiving the varicella vaccine. The AMA Council on Scientific Affairs studied this issue and presented this report to the House of Delegates in June 1997. METHODS: Information for the report was derived from published literature and from personal communications with medical and public health experts and the vaccine manufacturer. FINDINGS: Nosocomial outbreaks of varicella-zoster virus (VZV) can result in serious morbidity and mortality. Serological testing of healthcare workers and immunization of nonimmune individuals is recommended by infection control and infectious disease experts to prevent nosocomial transmission of VZV. While current data indicate that the vaccine is safe and poses minimal risks to both adults and children, ongoing research should address various concerns about the long-term safety, efficacy, and epidemiological impact of more widespread use of the vaccine. CONCLUSION: Unless contraindicated, all susceptible healthcare workers should receive the varicella vaccine. Whereas individuals with a definite history of VZV infection can be considered immune, those with a negative or uncertain history should undergo serological testing and, if seronegative, should be immunized.


Assuntos
Vacina contra Varicela , Varicela/prevenção & controle , Infecção Hospitalar/prevenção & controle , Pessoal de Saúde , Vacinação/normas , Adulto , American Medical Association , Guias como Assunto , Humanos , Segurança , Estados Unidos
13.
JAMA ; 279(14): 1100-7, 1998 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-9546570

RESUMO

OBJECTIVE: To deal with public and professional concern regarding possible overprescription of attention-deficit/hyperactivity disorder (ADHD) medications, particularly methylphenidate, by reviewing issues related to the diagnosis, optimal treatment, and actual care of ADHD patients and of evidence of patient misuse of ADHD medications. DATA SOURCES: Literature review using a National Library of Medicine database search for 1975 through March 1997 on the terms attention deficit disorder with hyperactivity, methylphenidate, stimulants, and stimulant abuse and dependence. Relevant documents from the Drug Enforcement Administration were also reviewed. STUDY SELECTION: All English-language studies dealing with children of elementary school through high school age were included. DATA EXTRACTION: All searched articles were selected and were made available to coauthors for review. Additional articles known to coauthors were added to the initial list, and a consensus was developed among the coauthors regarding the articles most pertinent to the issues requested in the resolution calling for this report. Relevant information from these articles was included in the report. DATA SYNTHESIS: Diagnostic criteria for ADHD are based on extensive empirical research and, if applied appropriately, lead to the diagnosis of a syndrome with high interrater reliability, good face validity, and high predictability of course and medication responsiveness. The criteria of what constitutes ADHD in children have broadened, and there is a growing appreciation of the persistence of ADHD into adolescence and adulthood. As a result, more children (especially girls), adolescents, and adults are being diagnosed and treated with stimulant medication, and children are being treated for longer periods of time. Epidemiologic studies using standardized diagnostic criteria suggest that 3% to 6% of the school-aged population (elementary through high school) may suffer from ADHD, although the percentage of US youth being treated for ADHD is at most at the lower end of this prevalence range. Pharmacotherapy, particularly use of stimulants, has been extensively studied and generally provides significant short-term symptomatic and academic improvement. There is little evidence that stimulant abuse or diversion is currently a major problem, particularly among those with ADHD, although recent trends suggest that this could increase with the expanding production and use of stimulants. CONCLUSIONS: Although some children are being diagnosed as having ADHD with insufficient evaluation and in some cases stimulant medication is prescribed when treatment alternatives exist, there is little evidence of widespread overdiagnosis or misdiagnosis of ADHD or of widespread overprescription of methylphenidate by physicians.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/diagnóstico , Transtorno do Deficit de Atenção com Hiperatividade/terapia , Estimulantes do Sistema Nervoso Central/uso terapêutico , Metilfenidato/uso terapêutico , Padrões de Prática Médica , Adolescente , American Medical Association , Transtorno do Deficit de Atenção com Hiperatividade/tratamento farmacológico , Transtorno do Deficit de Atenção com Hiperatividade/epidemiologia , Estimulantes do Sistema Nervoso Central/efeitos adversos , Criança , Comorbidade , Uso de Medicamentos , Feminino , Humanos , Masculino , Metilfenidato/efeitos adversos , Transtornos Relacionados ao Uso de Substâncias , Estados Unidos
14.
Am J Med ; 104(3): 264-71, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9552090

RESUMO

Concerns about funding of clinical research underlie all other problems identified at the Council on Scientific Affairs conference. Future National Institutes of Health (NIH) budgets are likely to be constant at best, and the general public expects cost containment to be an ongoing goal; this is exacerbated by the impending Medicare Trust Fund crisis. Meanwhile, traditional financial support of clinical research in academic medical centers (AMCs) through cross-subsidization is imperiled by competitive pressures largely caused by managed care. Although managed care organizations (MCOs) are potentially rich sources of funding and other resources, and some not-for-profit companies are conducting some research, for-profit MCOs have not demonstrated an understanding of the importance of clinical research. Young physicians are being discouraged from careers as clinical researchers and established investigators are "dropping out" because of demands for clinical productivity and competition for research grants, loss of patients/research subjects to managed care, perceived lack of status and compensation, and overall uncertainty about continued financial support. Efforts to assist current and potential clinical investigators are discussed in this report. Loss of patients, denial of reimbursement, and competition with MCOs and contract research organizations (CROs) have placed AMCs under unprecedented pressure. However, research centers located in AMCs have allowed investigators to conduct clinical research by providing a "protected environment." Furthermore, many AMCs are determined to continue conducting clinical research and are addressing related problems. Although the NIH will continue to be a major source of funding for clinical research, partnerships between various private and public entities provide important opportunities to maximize the productivity of all individuals and institutions involved. Potential partnerships include MCOs, AMCs, CROs, pharmaceutical companies and other industry, the Department of Defense, the Veterans Health Administration, practice-based physicians, and private foundations and patient support groups. "Partnerships in advocacy" for clinical research will be essential. Efforts to recruit for-profit MCOs to the clinical research endeavor identified in this report include (1) emphasizing issues of interest to them (eg, outcomes research); (2) stressing the significance of some research to the marketplace; (3) developing criteria to distinguish individual MCOs on the basis of their contribution to the public interest; (4) equating money spent on research with "R&D dollars" spent in nonmedical business enterprises; and (5) educating purchasers of health care (eg, corporate health plan directors) about clinical research. Conducting clinical research in all managed care settings requires leadership, the understanding and cooperation of physicians and support staff, wise use of limited resources (ie, funding only the best research projects), sound methodology, and above all, the perception that the research will ultimately improve patient care.


Assuntos
Pesquisa/tendências , American Medical Association , Humanos , Estados Unidos
16.
Eur J Pediatr Surg ; 6(5): 301-2, 1996 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8933136

RESUMO

We present a 15-year-old girl with an unusual clinical course of intractable thyrotoxicosis that was resistant to thiocarbamide therapy and propranolol. Although the latter beta-adrenergic blocking agent has been used as the sole drug in the preparation of thyrotoxicosis patients for thyroidectomy, it was unsatisfactory for control of our case. In contrast, the patient's clinical response to lithium carbonate 900-1500 mg/d for 10 days was very good and no side effects were observed. This demonstrates the importance of lithium as the drug of choice in thyrotoxic emergencies and uncontrolled preoperative patients when rapid and safe inhibition of thyroid hormone secretion is required.


Assuntos
Hipertireoidismo/terapia , Carbonato de Lítio/administração & dosagem , Pré-Medicação , Adolescente , Antitireóideos/farmacologia , Resistência a Múltiplos Medicamentos , Feminino , Humanos , Metimazol/farmacologia , Propranolol/farmacologia , Propiltiouracila/farmacologia , Tireoidectomia
17.
J Pediatr ; 129(3): 459-64, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8804341

RESUMO

A girl 5 years 11 months of age, belonging to an extensive kindred with multiple endocrine neoplasia, type IIA (MEN IIA), was found to have multifocal medullary thyroid carcinoma with metastasis in one paraglandular lymph node after positive findings on a calcium-pentagastrin stimulation test. Her sister, 3 years 8 months of age, also had an elevated calcitonin level, and thyroidectomy revealed C-cell hyperplasia and a focus of medullary thyroid carcinoma. These two cases underscore the need for prophylactic thyroidectomies in MEN IIA patients as young as 5 years of age and strict yearly provocative screening beginning at age 1 year.


Assuntos
Carcinoma Medular/diagnóstico , Carcinoma Medular/secundário , Neoplasia Endócrina Múltipla Tipo 2a/diagnóstico , Neoplasias da Glândula Tireoide/genética , Carcinoma Medular/genética , Carcinoma Medular/cirurgia , Criança , Pré-Escolar , Feminino , Humanos , Linfonodos/patologia , Metástase Linfática , Neoplasia Endócrina Múltipla Tipo 2a/genética , Neoplasia Endócrina Múltipla Tipo 2a/terapia , Neoplasias da Glândula Tireoide/diagnóstico , Neoplasias da Glândula Tireoide/patologia , Neoplasias da Glândula Tireoide/cirurgia , Tireoidectomia
19.
Sports Med ; 16(5): 305-15, 1993 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-8272686

RESUMO

The possibility that men might masquerade as women and be unfair competitors in women's sports is accepted as outrageous by athletes and the public alike. Since the 1930s, media reports have fuelled claims that individuals who once competed as female athletes subsequently appeared to be men. In most of these cases there was probably ambiguity of the external genitalia, possibly as a result of male pseudohermaphroditism. Nonetheless, beginning at the Rome Olympic Games in 1960, the International Amateur Athletics Federation (IAAF) began establishing rules of eligibility for women athletes. Initially, physical examination was used as a method for gender verification, but this plan was widely resented. Thus, sex chromatin testing (buccal smear) was introduced at the Mexico City Olympic Games in 1968. The principle was that genetic females (46,XX) show a single X-chromatic mass, whereas males (46,XY) do not. Unfortunately, sex chromatin analysis fell out of common diagnostic use by geneticists shortly after the International Olympic Committee (IOC) began its implementation for gender verification. The lack of laboratories routinely performing the test aggravated the problem of errors in interpretation by inexperienced workers, yielding false-positive and false-negative results. However, an even greater problem is that there exist phenotypic females with male sex chromatin patterns (e.g. androgen insensitivity, XY gonadal dysgenesis). These individuals have no athletic advantage as a result of their congenital abnormality and reasonably should not be excluded from competition. That is, only the chromosomal (genetic) sex is analysed by sex chromatin testing, not the anatomical or psychosocial status. For all the above reasons sex chromatin testing unfairly excludes many athletes. Although the IOC offered follow-up physical examinations that could have restored eligibility for those 'failing' sex chromatin tests, most affected athletes seemed to prefer to 'retire'. All these problems remain with the current laboratory based gender verification test, polymerase chain reaction based testing of the SRY gene, the main candidate for male sex determination. Thus, this 'advance' in fact still fails to address the fundamental inequities of laboratory based gender verification tests. The IAAF considered the issue in 1991 and 1992, and concluded that gender verification testing was not needed. This was thought to be especially true because of the current use of urine testing to exclude doping: voiding is observed by an official in order to verify that a sample from a given athlete has actually come from his or her urethra. That males could masquerade as females in these circumstances seems extraordinarily unlikely. Screening for gender is no longer undertaken at IAAF competitions.


Assuntos
Análise para Determinação do Sexo , Medicina Esportiva , Transtornos do Desenvolvimento Sexual/genética , Feminino , Humanos , Masculino , Reação em Cadeia da Polimerase , Cromatina Sexual
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