RESUMO
Interaction between hypoxia and coagulation is important given the increased risk of thrombotic diseases in chronically hypoxic patients who reside at sea level and in residents at high altitude. Hypoxia alters the proteome of platelets favouring a prothrombotic phenotype, but studies of activation and consumption of specific coagulation factors in hypoxic humans have yielded conflicting results. We tested blood from 63 healthy lowland volunteers acclimatizing to high altitude (5,200 m) using thromboelastometry and assays of platelet function to examine the effects of hypoxia on haemostasis. Using data from two separate cohorts of patients following identical ascent profiles, we detected a significant delay in clot formation, but increased clot strength by day 7 at 5,200 m. The latter finding may be accounted for by the significant rise in platelet count and fibrinogen concentration that occurred during acclimatization. Platelet function assays revealed evidence of platelet hyper-reactivity, with shortened PFA-100 closure times and increased platelet aggregation in response to adenosine diphosphate. Post-expedition results were consistent with the normalization of coagulation following descent to sea level. These robust findings indicate that hypoxia increases platelet reactivity and, with the exception of the paradoxical delay in thromboelastometry clotting time, suggest a prothrombotic phenotype at altitude. Further work to elucidate the mechanism of platelet activation in hypoxia will be important and could impact upon the management of patients with acute or chronic hypoxic respiratory diseases who are at risk of thrombotic events.
Assuntos
Aclimatação , Altitude , Testes de Função Plaquetária , Tromboelastografia , Trombose/fisiopatologia , Adolescente , Adulto , Coagulação Sanguínea , Bolívia , Estudos de Coortes , Feminino , Voluntários Saudáveis , Hemostasia , Humanos , Hipóxia , Masculino , Oxigênio/química , Proteoma , Risco , Adulto JovemRESUMO
OBJECTIVE: To measure the circulating concentrations of nitric oxide (NO) adducts with NO bioactivity after inhaled NO (iNO) therapy in infants with pulmonary hypertension. STUDY DESIGN: In this single center study, 5 sequential blood samples were collected from infants with pulmonary hypertension before, during, and after therapy with iNO (n = 17). Samples were collected from a control group of hospitalized infants without pulmonary hypertension (n = 16) and from healthy adults for comparison (n = 12). RESULTS: After beginning iNO (20 ppm) whole blood nitrite levels increased approximately two-fold within 2 hours (P<.01). Whole blood nitrate levels increased to 4-fold higher than baseline during treatment with 20 ppm iNO (P<.01). S-nitrosohemoglobin increased measurably after beginning iNO (P<.01), whereas iron nitrosyl hemoglobin and total hemoglobin-bound NO-species compounds did not change. CONCLUSION: Treatment of pulmonary hypertensive infants with iNO results in increases in levels of nitrite, nitrate, and S-nitrosohemoglobin in circulating blood. We speculate that these compounds may be carriers of NO bioactivity throughout the body and account for peripheral effects of iNO in the brain, heart, and other organs.
Assuntos
Hemoglobinas/metabolismo , Hipertensão Pulmonar/tratamento farmacológico , Nitratos/sangue , Óxido Nítrico/farmacologia , Nitritos/sangue , Vasodilatadores/farmacologia , Administração por Inalação , Adulto , Feminino , Humanos , Hipertensão Pulmonar/sangue , Lactente , Recém-Nascido , Masculino , Óxido Nítrico/administração & dosagem , Resultado do Tratamento , Vasodilatadores/administração & dosagemRESUMO
After exposure to asphyxia, infants may develop both prolonged, clinically evident seizures and shorter, clinically silent seizures; however, their effect on cerebral tissue oxygenation is unclear. We therefore examined the hypothesis that the increase in oxygen delivery during postasphyxial seizures might be insufficient to meet the needs of increased metabolism, thus causing a fall in tissue oxygenation, in unanesthetized near-term fetal sheep in utero (gestational age 125+/-1 days). Fetuses were administered an infusion of the specific adenosine A1 receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine, followed by 10 mins of asphyxia induced by complete umbilical cord occlusion. The fetuses then recovered for 3 days. Sixty-one episodes of electrophysiologically defined seizures were identified in five fetuses. Tissue PO(2) (tPO(2)) did not change significantly during short seizures (<3.5 mins), 5.2+/-0.2 versus baseline 5.6+/-0.1 mm Hg (NS), but fell to 2.2+/-0.2 mm Hg during seizures lasting more than 3.5 mins (P<0.001). During prolonged seizures, cortical blood flow did not begin to increase until tPO(2) had begun to fall, and then rose more slowly than the increase in metabolism, with a widening of the brain to blood temperature gradient. In conclusion, in the immature brain, during prolonged, but not short seizures, there is a transient mismatch between cerebral blood flow and metabolism leading to significant cerebral deoxygenation.
Assuntos
Asfixia/metabolismo , Encéfalo/metabolismo , Feto/metabolismo , Oxigênio/metabolismo , Convulsões/metabolismo , Doenças dos Ovinos/metabolismo , Ovinos/embriologia , Animais , Asfixia/complicações , Asfixia/veterinária , Temperatura Corporal , Feminino , Gravidez , Convulsões/etiologia , Convulsões/veterinária , Ovinos/metabolismo , Doenças dos Ovinos/etiologia , Fatores de TempoRESUMO
OBJECTIVE: Jamaica has long been considered to be a homophobic society. The aim of this survey was to examine the attitudes of the Jamaican populance towards homosexuality, thus shedding light on the important issue of homosexuality, disclosure of one's sexual preference and the relationship to the HIV/AIDS epidemic. METHODS: There have been several subjective reports on the issue of homosexuality in Jamaica. Many of these reports have suggested that Jamaica is not truly a homophobic society. No objective study on attitudes towards homosexuality in Jamaica has been done to date; this is an attempt in that regard. A survey was conducted in the Kingston and St.Andrew region. A questionnaire consisting of 17 knowledge and attitude items with six items to determine demographic data was prepared. This was administered to every third person in 6 designated areas, ensuring that equal numbers of males and females aged 16 years and over were polled. RESULTS: The analysis indicates that the majority of those surveyed thought that the homosexuality lifestyle was unaccepatable. Of significance, views varied depending on the level of educational attainment: 100 percent of persons with primary level education found homosexuality unacceptable in contrast with 76 percent of those with teritiary level education with a similar opinion (p=0.028). There was a generally negative attitude towards befriending an acknowledged homosexual or having such persons in positions of authority. Many participants agreed that homosexual partners should have access to social services, including insurance plans, with 37 percent in outright agreement and 21 percent remaining neutral. There was a dramatic decrease in the number of persons who believed that HIV was solely a homosexual disease (13 percent) in contrast with the results of a 1989 survey conducted by the Ministry of Health (81 percent). CONCLUSION: Despite changing global opinions of the homosexual lifestyles, several biases still remain within the Jamaican society. These conditions force homosexuals to remain ensconced within the cloak of the more acceptable heterosexual lifestyle, which may have significant social and health implications. (AU)
Assuntos
Humanos , Masculino , Homossexualidade , Atitude , Jamaica , Interpretação Estatística de Dados , Viés , Variações Dependentes do Observador , Viés de SeleçãoRESUMO
BACKGROUND: Limited joint mobility (LJM) in childhood insulin-dependent (type 1) diabetes is associated with a substantially increased risk of microvascular complications. Cross-sectional studies have not demonstrated a relationship between LJM and metabolic control. This study was designed to determine whether glycemic control, as measured by glycohemoglobin (hgbA1C) levels from the onset of diabetes, is associated with the occurrence of LJM. METHOD: Probands (n = 18) had hgbA1C values and recorded observation of joint function from soon after onset of their diabetes. Controls (n = 40) were matched to probands for gender and age at diagnosis and had follow-up beyond the age at which the proband was found to have LJM. RESULTS: The odds ratio for occurrence of LJM for the mean hgbA1C from diabetes onset was 1.46, 95% confidence limits 1.07 to 2.00. Thus, for every unit increase in average hgbA1C, there was approximately a 46% increase in the risk of LJM. When hgbA1C was dichotomized, the OR for hgbA1C of more than 8% was 2.55, and the OR was 4.54 if the hgbA1C was greater than 12%. Age at diagnosis and duration of diabetes were not independent prognostic factors for LJM. CONCLUSION: Glycemic control from onset of diabetes is strongly associated with occurrence of LJM.
Assuntos
Diabetes Mellitus Tipo 1/complicações , Diabetes Mellitus Tipo 1/metabolismo , Hemoglobinas Glicadas/análise , Artropatias/prevenção & controle , Estudos de Casos e Controles , Criança , Diabetes Mellitus Tipo 1/tratamento farmacológico , Feminino , Seguimentos , Humanos , Artropatias/epidemiologia , Artropatias/etiologia , Masculino , Prognóstico , Fatores de Risco , Fatores de TempoRESUMO
Neck pain often occurs in the absence of neurologic findings, and the diagnostic dilemma of the clinician is to determine if there is a definable lesion. Radiographically, the cervical spine is commonly involved, especially in persons older than 50 years. Excluding soft-tissue inflammation and spasm, osteoarthritis is the most common rheumatic disease of the cervical spine. Radiculopathy and myelopathic involvement from disk, foraminal, or spinal canal impingement are all sequelae of this disease. Other diseases, such as DISH, rheumatoid arthritis, and ankylosing spondylitis, can affect the spine as well. Assessment of the integrity of the atlantoaxial joint is important in avoiding neurologic compromise.
Assuntos
Artrite , Vértebras Cervicais , Artrite/diagnóstico , Artrite/fisiopatologia , Artrite/terapia , Humanos , Doenças da Coluna Vertebral/diagnóstico , Doenças da Coluna Vertebral/fisiopatologia , Doenças da Coluna Vertebral/terapiaRESUMO
PIP: Women have generally assumed responsibility for contraception since the appearance of oral contraceptives and IUDs. But AIDS prevention programs are now asking women to assume responsibility for safer sex through use of condoms, a male method. Women are being asked to carry condoms, to negotiate their use each time they have sex, and to insist if the partner resists. The problem with this strategy is that frequently it is the male partner who makes sexual decisions, and women have less negotiating power. Women are considered feminine if they assume a passive role in sexual activity. This work suggests strategies to improve the negotiating power of women. Options and problems of speaking about safer sex vary in accordance with the nature of the relationship. A woman with a new partner can try to ascertain his sexual history, but may gain no information on his probable health even if he tells her the truth. It may be easier to convince him to use a condom at least in the beginning of the romance. Women working in the sex industry often have greater trouble convincing their friends and lovers to use a condom than their clients. Some family planning workers have begun to speak of safer sex with all their clients. Role playing and workshops or discussions with small groups of women having similar problems may help women overcome their reticence about discussing sexual topics. Some general suggestions to help women negotiate safer sex include choosing an opportune moment and planning in advance what to say; daring to speak directly without beating around the bush (the partner may also be gathering courage to speak); practicing placing condoms on objects and if necessary placing one on the partner without speaking; being honest with the partner about sex, love, and fidelity; and remembering that protection from condoms is mutual given that it is not possible to know who is infected. Until now, programs to help women practice safer sex have concentrated on sex industry workers or family planning clients. Adolescents are a particularly vulnerable group because of their usual lack of knowledge when the initiate their sex lives. Some sex education classes are beginning to include materials instructing young girls in how to negotiate with boys seeking sexual favors. Printed materials such as simple pamphlets made available by family planning programs to young people can help to raise the topics of HIV infection and safer sex. Greater societal awareness of the problem and improvements in the opportunities for women to exercise their basic rights will be needed to ensure all women the power to protect their own health.^ieng
Assuntos
Síndrome da Imunodeficiência Adquirida , Preservativos , Identidade de Gênero , Comportamentos Relacionados com a Saúde , Diretrizes para o Planejamento em Saúde , Relações Interpessoais , Filosofia , Comportamento Sexual , Comportamento , Anticoncepção , Doença , Serviços de Planejamento Familiar , Infecções por HIV , Organização e Administração , Comportamento Social , VirosesRESUMO
Many types of arthritis can disturb the normal lumbar anatomy. This review intentionally omits many endocrine, metabolic, and genetic disorders that ultimately lead to breakdown of cartilage. Osteoarthritis remains the most common cause of sustained back pain as well as one of the most compensable disabilities in the United States. As so many other authors have noted, more scientific investigation is needed, and funding is imperative to effect significant changes.
Assuntos
Artrite , Vértebras Lombares , Artrite/diagnóstico , Artrite/patologia , Humanos , Hiperostose Esquelética Difusa Idiopática/diagnóstico , Hiperostose Esquelética Difusa Idiopática/patologia , Vértebras Lombares/patologia , Osteoartrite/diagnóstico , Osteoartrite/patologia , Doenças da Coluna Vertebral/diagnóstico , Doenças da Coluna Vertebral/patologia , Espondilite Anquilosante/diagnóstico , Espondilite Anquilosante/patologiaRESUMO
The authors have presented what they believe is the only reported case of a stress fracture of the tarsal middle cuneiform bone. Stress fracture pathogenesis, as well as diagnosis and treatment, were reviewed. It has been proposed that the middle cuneiform may be subject to increased stress in the runner during the propulsive phase, as this is the midfoot bone that transmits weight proximally in the medial column. This is evident by studying the cancellous structure of the tarsal bones. The ligamentous and osseous architecture of this region also can produce a midfoot buckling when the foot is plantarflexed against resistance. Prompt diagnosis and treatment is the key in preventing the stress fracture from becoming a chronic source of discomfort.
Assuntos
Fraturas de Estresse , Ossos do Tarso/lesões , Fraturas de Estresse/diagnóstico , Fraturas de Estresse/etiologia , Fraturas de Estresse/fisiopatologia , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
The authors review 24 cases of acute renal failure of obstetric etiology occurred in Hospital Santo Tomás, which represents a frequency of 1.375/10,000, with a bimodal distribution and the main causes were toxemia of pregnancy and sepsis. All cases were of the oliguric type and a kidney biopsy was performed in 17 cases, revealing an acute tubular necrosis in 16 and a diffuse cortical necrosis in the other case. Two patients (8.3%) died and one did not received nephrology treatment as the other 23 patients. The fetal mortality was 37.5% and the Apgar was good in 2, fair in one and bad in 2. A 50% of the complications were infections and nine patients tolerated different surgical procedures after the installation of the acute renal failure. The follow-up of 12 patients shows no evidence of renal failure.