RESUMEN

PURPOSE: To report three cases of Loa loa infestation presenting over the course of 12 months to ophthalmology departments in the South West Thames region around London. METHODS: Case series (three case histories are described) and literature review. RESULTS: All three patients had a history of travel to West Africa. All had worms surgically removed and were referred to an infectious diseases hospital, where these were confirmed as adult Loa loa nematodes and treatment was initiated. CONCLUSIONS: Although ocular loiasis is endemic in West Africa, European ophthalmologists in areas of diverse ethnicity should be aware that it is presenting increasingly frequently, that there is often no history of recent travel abroad, and that loiasis is a differential diagnosis for any 'at-risk' patient with an unexplained foreign body sensation.

Asunto(s)

Infecciones Parasitarias del Ojo/parasitología , Loiasis/parasitología , Adulto , Animales , Conjuntiva/parasitología , Conjuntiva/cirugía , Infecciones Parasitarias del Ojo/diagnóstico , Infecciones Parasitarias del Ojo/cirugía , Femenino , Humanos , Loa/aislamiento & purificación , Loiasis/diagnóstico , Loiasis/cirugía , Londres , Masculino , Resultado del Tratamiento , Adulto Joven

RESUMEN

Cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) is regarded with other molecules such as HLA, PTPN22 and CARD15 as genetic master switches of autoimmunity. Single nucleotide polymorphisms (SNPs) in the genes encoding these molecules have been associated with autoimmune conditions. We analysed the SNPs -318C/T and 49A/G in CTLA-4 in patients with Behcet's disease (BD), patients with intermediate uveitis and appropriate controls. Blood was collected from 236 patients with BD from the UK and the Middle East (ME), all fulfilling the International Study Group criteria for the diagnosis of BD, and 143 patients with idiopathic intermediate uveitis were recruited from the Medical Eye Unit at St Thomas' Hospital. Samples from healthy individuals from each geographical centre were used as controls. DNA was prepared by standard methods, and SNPs -318 and 49 in CTLA-4 were detected by a polymerase chain reaction-sequence specific primers (PCR-SSP) assay using primer mixes. The results showed that there was no association with either polymorphism in patients with BD from the UK or the ME. Similarly, there was no association in patients with intermediate uveitis. Moreover, there was no association with SNP in CTLA-4 and disease manifestations in BD or outcome in patients with intermediate uveitis. Both BD and intermediate uveitis have HLA associations, but there is no difference in distribution of CTLA-4 polymorphisms that are associated with other autoimmune diseases. The lack of association with polymorphisms in CTLA-4 and other master controlling genes of autoimmunity suggests that mechanisms that mediate such a description for BD and intermediate uveitis have still to be elucidated.

Asunto(s)

Antígenos CD/genética , Síndrome de Behçet/genética , Polimorfismo de Nucleótido Simple , Uveítis Intermedia/genética , Síndrome de Behçet/patología , Antígeno CTLA-4 , Estudios de Casos y Controles , Estudios de Seguimiento , Predisposición Genética a la Enfermedad , Humanos , Persona de Mediana Edad , Estudios Prospectivos

RESUMEN

OBJECTIVES: This study characterized the AIDS epidemic among urban men who have sex with men (MSM). METHODS: A probability sample of MSM was obtained in 1997 (n = 2881; 18 years and older) from New York, Los Angeles, Chicago, and San Francisco, and HIV status was determined through self-report and biological measures. RESULTS: HIV prevalence was 17% (95% confidence interval = 15%, 19%) overall, with extremely high levels in African Americans (29%), MSM who used injection drugs (40%), "ultraheavy" noninjection drug users (32%), and less educated men (< high school, 37%). City-level HIV differences were non-significant once these other factors were controlled for. In comparing the present findings with historical data based on public records and modeling, HIV prevalence appears to have declined as a result of high mortality (69%) and stable, but high, incidence rates (1%-2%). CONCLUSIONS: Although the findings suggest that HIV prevalence has declined significantly from the mid-1980s, current levels among urban MSM in the United States approximate those of sub-Saharan countries (e.g., 14%-25%) and are extremely high in many population subsegments. Despite years of progress, the AIDS epidemic continues unabated among subsegments of the MSM community.

Asunto(s)

Brotes de Enfermedades , Infecciones por VIH/epidemiología , Homosexualidad Masculina/estadística & datos numéricos , Adolescente , Adulto , Etnicidad/estadística & datos numéricos , Encuestas Epidemiológicas , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Prevalencia , Factores de Riesgo , Factores Socioeconómicos , Trastornos Relacionados con Sustancias/epidemiología , Estados Unidos/epidemiología , Población Urbana/estadística & datos numéricos

RESUMEN

The National Aeronautics and Space Administration (NASA) is conducting a series of closed chamber environmental tests, called the Lunar Mars Life Support Test Project (LMLSTP), which is designed to provide data for the development of surface habitats for the Moon and Mars. These surface habitats will be closed loop environmental systems that will recycle air and water and will grow crops to provide food for crew members. In conjunction with these tests, the Food Systems Engineering Facility at the Johnson Space Center (JSC) tested a 10-day vegetarian menu based on items that can be made from the projected crop list for these habitats. The planned menu met most of the nutritional requirements of the four crew members and was found highly acceptable. Automation of the food preparation and processing equipment was strongly recommended because the preparation time was judged excessive. The waste generated was largely due to leftovers.

Asunto(s)

Dieta Vegetariana , Sistemas Ecológicos Cerrados , Sistemas de Manutención de la Vida , Planificación de Menú , Simulación del Espacio , Carbohidratos de la Dieta/análisis , Grasas de la Dieta/análisis , Proteínas en la Dieta/análisis , Ingestión de Alimentos , Manipulación de Alimentos , Humanos , Marte , Luna , Necesidades Nutricionales , Valor Nutritivo

RESUMEN

Opioids are some of the most efficacious analgesics used in humans. Prolonged administration of opioids, however, often causes the development of drug tolerance, thus limiting their effectiveness. To explore the molecular basis of those mechanisms that may contribute to opioid tolerance, we have isolated a cDNA for the human mu opioid receptor, the target of such opioid narcotics as morphine, codeine, methadone, and fentanyl. The receptor encoded by this cDNA is 400 amino acids long with 94% sequence similarity to the rat mu opioid receptor. Transient expression of this cDNA in COS-7 cells produced high-affinity binding sites to mu-selective agonists and antagonists. This receptor displays functional coupling to a recently cloned G-protein-activated K+ channel. When both proteins were expressed in Xenopus oocytes, functional desensitization developed upon repeated stimulation of the mu opioid receptor, as observed by a reduction in K+ current induced by the second mu receptor activation relative to that induced by the first. The extent of desensitization was potentiated by both the multifunctional calcium/calmodulin-dependent protein kinase and protein kinase C. These results demonstrate that kinase modulation is a molecular mechanism by which the desensitization of mu receptor signaling may be regulated at the cellular level, suggesting that this cellular mechanism may contribute to opioid tolerance in humans.

Asunto(s)

Proteínas Quinasas Dependientes de Calcio-Calmodulina/metabolismo , Narcóticos/metabolismo , Canales de Potasio/metabolismo , Proteína Quinasa C/metabolismo , Procesamiento Proteico-Postraduccional , Receptores Opioides mu/metabolismo , Adolescente , Adulto , Anciano , Secuencia de Aminoácidos , Animales , Unión Competitiva , Química Encefálica , Proteína Quinasa Tipo 2 Dependiente de Calcio Calmodulina , Línea Celular Transformada , Chlorocebus aethiops , ADN Complementario/genética , Tolerancia a Medicamentos , Encefalina Ala(2)-MeFe(4)-Gli(5) , Encefalinas/metabolismo , Femenino , Proteínas de Unión al GTP/metabolismo , Humanos , Activación del Canal Iónico/efectos de los fármacos , Masculino , Persona de Mediana Edad , Datos de Secuencia Molecular , Oocitos , Fosforilación , Procesamiento Proteico-Postraduccional/efectos de los fármacos , ARN Mensajero/biosíntesis , Ratas , Receptores Opioides mu/genética , Proteínas Recombinantes de Fusión/metabolismo , Alineación de Secuencia , Homología de Secuencia de Aminoácido , Transducción de Señal/efectos de los fármacos , Xenopus laevis

RESUMEN

Opioid drugs exert a wide spectrum of physiological and behavioral effects, including effects on pain perception, mood, motor control and autonomic functions. The effects of opioids are mediated via a family of membrane-bound receptors, of which the most extensively characterized are the mu, delta and kappa receptors. We have now cloned the human homolog of the mu opioid receptor and, in the present study, we have examined its pharmacological profile. The human mu receptor has high affinities for several alkaloids of high abuse potential as well as a variety of peptide and nonpeptide drugs characterized previously as mu-selective, but not delta- or kappa-selective. Most importantly, the human mu receptor has higher affinity for morphine and methadone than does the rat mu receptor, despite the fact that these receptors are 95% identical at the amino acid level. The labeling of the receptor by agonist was decreased by nonhydrolyzable GTP analogs and by pertussis toxin treatment of cells expressing the human mu receptor, consistent with the coupling of the receptor to guanine nucleotide binding proteins. The human mu receptor functionally couples to the inhibition of adenylyl cyclase in a stereospecific and naloxone-reversible manner. We have also investigated the distribution of mRNAs encoding the mu receptor in human brain by Northern analysis, which demonstrates the existence of multiple transcripts of 13.5, 11, 4.3 and 2.8 kb, which were highly expressed in the hypothalamus, thalamus and subthalamic nucleus, more moderately expressed in the amygdala and caudate nucleus and which demonstrated lowest levels of expression in the hippocampus, substantia nigra and corpus callosum.(ABSTRACT TRUNCATED AT 250 WORDS)

Asunto(s)

Receptores Opioides mu/metabolismo , Animales , Encéfalo/fisiología , Clonación Molecular , AMP Cíclico/metabolismo , ADN Complementario/genética , Encefalina Ala(2)-MeFe(4)-Gli(5) , Encefalinas/metabolismo , Expresión Génica , Guanosina 5'-O-(3-Tiotrifosfato)/farmacología , Humanos , Ligandos , Morfina/farmacología , ARN Mensajero/genética , Ensayo de Unión Radioligante , Ratas , Receptores Opioides mu/efectos de los fármacos , Proteínas Recombinantes

RESUMEN

The serotonin 1c (5-HT1C) receptor is found in many brain regions, but is particularly enriched on the epithelial cells of the choroid plexus. A major challenge in neurobiology is to delineate the molecular processes that regulate the specific pattern of neuronal gene expression in the brain. As an initial step towards identifying cis-acting DNA sequences that control the expression of the 5-HT1C receptor, we have isolated the promoter sequence of its gene. Sequence analysis of a 1.8 kb fragment indicated that the 3' end of this fragment overlaps with the 5' untranslated region of the 5-HT1C receptor mRNA, and primer extension using mouse brain poly(A)+ RNA mapped the transcription initiation site within this fragment. There are a number of sequence elements upstream from the transcription initiation site that are homologous to regulatory elements found in other eucaryotic genes. To determine the promoter activity, a plasmid was constructed that contains this fragment as promoter region and the cDNA for the 5-HT1C receptor as the reporter. When injected into the nucleus of Xenopus oocytes, this construct resulted in functional expression of the reporter gene. Primer extension using the RNA extracted from the injected oocytes indicated a single transcription initiation site of the reporter mRNA. These results suggest that the 5-HT1C receptor was functionally expressed under the promoter activity of the 1.8 kb 5' sequence of its gene. This system will be useful for further analysis of the cis-acting elements in the promoter region of the 5-HT1C receptor gene and the trans-acting factors that regulate tissue-specific expression of the receptor.

Asunto(s)

Regulación de la Expresión Génica/fisiología , Iniciación de la Cadena Peptídica Traduccional/genética , Regiones Promotoras Genéticas , Receptores de Serotonina/genética , Animales , Secuencia de Bases , Ratones , Datos de Secuencia Molecular , Oocitos , Xenopus

RESUMEN

Data from the 1989 Communication Technologies cross-sectional survey of gay men in San Francisco indicate that both levels and correlates of sexual risk are different between younger and older gay men. Gay men under the age of 30 report higher risk behavior for human immunodeficiency virus (HIV) infection than do gay men who are 30 years of age or older. Further, the set of correlates of unprotected anal intercourse are different between younger and older gay men. Both young and old gay men report that having a primary partner and a lower perceived impact of the AIDS epidemic on their sexual behavior are associated with risk. However, among young gay men, reporting a lower attributed risk for HIV infection to unprotected anal intercourse, higher concern about AIDS risks, and shorter length of residence in San Francisco are positively correlated with risk-taking behavior. These associations were not statistically significant among gay men 30 years of age or older. It appears that the circumstances and/or reasons for taking sexual risk are different between older and younger gay men. Prevention programs must be designed so that they are sensitive to the needs of each generation of gay men.

Asunto(s)

Infecciones por VIH/epidemiología , Conducta Sexual , Adolescente , Adulto , Factores de Edad , Estudios Transversales , Infecciones por VIH/psicología , Humanos , Masculino , Asunción de Riesgos , San Francisco/epidemiología

RESUMEN

Employed data from two longitudinal surveys of gay men in San Francisco (a) to examine for cohort (Study 1) and attrition (Studies 1 and 2) bias effects on reported changes in condom use by gay men and (b) to investigate predictors of condom use (Study 2). Substantial increases in condom use were observed, and these changes were unrelated to attrition and cohort bias. In terms of predictors of condom use, men who always used condoms had higher levels of social support from informal sources of help, had more positive expectations that condoms would have positive interpersonal and personal consequences, and were more likely to be HIV positive than men who used condoms occasionally or never. The results are discussed in terms of their implications for HIV-prevention research.

---

PIP: 2 research studies of changes in condom use among homosexual males in San Francisco for the period 1984-88 are discussed. The 1st study examined attrition and cohort bias effects on self-reported condom use in a longitudinal cohort and multiple sample investigation. An initial baseline sample of 500 self-identified gay men was sampled and interviewed by telephone as the longitudinal cohort, with 3 cross-sectional samples later surveyed for comparison. The frequency of receptive or insertive anal intercourse with and without condoms with primary and secondary sex partners was queried for the 30-day period prior to the survey in both studies. This 1st study found a 4-fold increase in condom use over the period 1984-87 to be neither effected by repeated assessments of the longitudinal cohort, nor respondent attrition. As determinants of condom use in this population for the period 1984-88, the 2nd study examined the influence of formal and informal social support for sex behavior change, being in a mutually monogamous sexual relationships, knowing the primary partner's HIV-antibody status, knowing one's antibody status, and the expected consequences of condom use on one's self-worth, sexual pleasure, health, and perceptions of one's sex partner. Research was based on AIDS Behavioral Research Project data obtained through recruitment in bathhouses and gay bars. 529 predominantly white, while collar, college-educated men of mean age 39 years remained in the study through 1988. While condom use increased by almost 4-fold, these men have been slower to change condom use behavior than respondents in the 1st study. Informal support and knowing one's HIV status are strong predictors of condom use 1 year later. Men always using condoms were found to have more social support from informal sources, more positive expectations of condoms, positive interpersonal and personal consequences, and were more likely to be HIV-positive than occasional or non-users. Programs best suited to effect condom use changes will focus on social support, sexual pleasure, self-worth, and relationship issues. Attention should also be placed upon the erotic/pleasure dimension of using condoms, changing community norms, and factors influencing HIV-negative people to take precautions against HIV infection. Methodological limitations are discussed regarding result reliability and validity, with further research encouraged.

Asunto(s)

Dispositivos Anticonceptivos Masculinos/estadística & datos numéricos , Infecciones por VIH/prevención & control , Homosexualidad/psicología , Adulto , Estudios de Cohortes , Estudios Transversales , Infecciones por VIH/psicología , Infecciones por VIH/transmisión , Seroprevalencia de VIH/tendencias , Conocimientos, Actitudes y Práctica en Salud , Humanos , Estudios Longitudinales , Masculino , Asunción de Riesgos , San Francisco

RESUMEN

A community-based programme of education and counselling in San Francisco aims to diminish the spread of AIDS. Some success appears to have been achieved in persuading high-risk groups to modify their sexual behaviour in ways likely to produce this result

Asunto(s)

Síndrome de Inmunodeficiencia Adquirida , Educación en Salud/métodos , Estados Unidos

Asunto(s)

Síndrome de Inmunodeficiencia Adquirida , Estados Unidos

Asunto(s)

Síndrome de Inmunodeficiencia Adquirida , Estados Unidos

Asunto(s)

Síndrome de Inmunodeficiencia Adquirida , Estados Unidos

Asunto(s)

Competencia Clínica , Enfermería Práctica/educación , Curriculum , Noruega