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1.
Diabet Med ; 32(9): 1186-92, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25604893

RESUMEN

AIMS: To determine prevalence and incidence estimates for clinically recognized cases of Type 1 diabetes from the Life For a Child Program (LFAC) with onset < 26 years in six representative districts, and the capital, of Rwanda. METHODS: Cases were identified from the LFAC registry and visits to district hospitals. Denominators were calculated from district-level population surveys. Period prevalence data were collected from 1 August 2011 to 31 July 2012 and annual incidence rates were calculated, retrospectively, for 2004-2011. Ninety-five per cent confidence intervals (95% CI) were calculated using a Poisson distribution. RESULTS: The prevalence of known Type 1 diabetes in seven districts in Rwanda for ages < 26 years was 16.4 [95% CI 14.6-18.4]/100 000 and for < 15 years was 4.8 [3.5-6.4]/100 000. Prevalence was higher in females (18.5 [15.8-21.4]/100 000) than males (14.1 [11.8-16.7]/100 000; P = 0.01) and rates increased with age. The annual incidence rate for those < 26 years was stable between 2007 and 2011 with a mean incidence over that time of 2.7 [2.0-3.7]/100 000 ( < 15 years = 1.2 [0.5-2.0]/100 000). Incidence rates were higher in females than males and peaked in males at ages 17 and 22 years and in females at age 18 years. CONCLUSIONS: Our report of known Type 1 diabetes cases shows lower incidence and prevalence rates in Rwanda than previously reported in the USA and most African countries. Incidence of recognized cases has increased over time, but has recently stabilized. However, the likelihood of missed cases due to death before diagnosis and misdiagnosis is high and therefore more definitive studies are needed.


Asunto(s)
Diabetes Mellitus Tipo 1/epidemiología , Adolescente , Distribución por Edad , Niño , Preescolar , Humanos , Incidencia , Lactante , Prevalencia , Salud Rural/estadística & datos numéricos , Rwanda/epidemiología , Distribución por Sexo , Salud Urbana/estadística & datos numéricos , Adulto Joven
2.
Nature ; 414(6864): 617-9, 2001 Dec 06.
Artículo en Inglés | MEDLINE | ID: mdl-11740553

RESUMEN

The nature of dark matter remains mysterious, with luminous material accounting for at most approximately 25 per cent of the baryons in the Universe. We accordingly undertook a survey looking for the microlensing of stars in the Large Magellanic Cloud (LMC) to determine the fraction of Galactic dark matter contained in massive compact halo objects (MACHOs). The presence of the dark matter would be revealed by gravitational lensing of the light from an LMC star as the foreground dark matter moves across the line of sight. The duration of the lensing event is the key observable parameter, but gives non-unique solutions when attempting to estimate the mass, distance and transverse velocity of the lens. The survey results to date indicate that between 8 and 50 per cent of the baryonic mass of the Galactic halo is in the form of MACHOs (ref. 3), but removing the degeneracy by identifying a lensing object would tighten the constraints on the mass in MACHOs. Here we report a direct image of a microlens, revealing it to be a nearby low-mass star in the disk of the Milky Way. This is consistent with the expected frequency of nearby stars acting as lenses, and demonstrates a direct determination of a lens mass from a microlensing event. Complete solutions such as this for halo microlensing events will probe directly the nature of the MACHOs.

3.
J Insect Physiol ; 47(6): 629-637, 2001 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-11249952

RESUMEN

The basal membrane potential (V(b)) of Locusta Malpighian tubule cells in control saline results from its relatively high permeability to potassium. In the presence of 1 mM barium added to the control saline V(b) hyperpolarized from a mean resting potential of -72.1 mV to -90.1 mV. On substituting rubidium for potassium in the control saline, V(b) also hyperpolarized to a value of -91.4 mV. Rubidium was also similarly effective in hyperpolarizing the basal membrane even in the presence of control concentrations of potassium in the bathing medium. Substitution of rubidium for potassium also effected a approximately 50% reduction in the rate of fluid secretion. The action of inhibitors on V(b) in the presence of rubidium showed that V(b) under these conditions probably originated from the bafilomycin-sensitive electrogenic potential generated across the apical membrane by a V-type ATPase. The responses of V(b) to potassium, barium and rubidium and their inhibition of fluid secretion suggest the presence of a substantial rubidium-blockable potassium conductance located on the basal membrane of Locusta Malpighian tubule cells.

4.
Insect Biochem Mol Biol ; 28(4): 201-11, 1998 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-9684329

RESUMEN

Apical and basal membrane fractions from Locusta Malpighian tubules were prepared and were characterized by marker enzyme analysis. The apical membranes contained an azide- and orthovanadate-insensitive ATPase activity that was inhibited by bafilomycin A1 (IC50 = 0.44 nM) and NEM (IC50 = 2.15 microM), and thus was characterized as putative V-type ATPase. The enzyme was stimulated by a variety of monovalent cations (Tris > K = Na > choline > Li = Rb) maximal stimulation occurring at 30-40 mM. It was also stimulated by a variety of monovalent anions (maximal activation 30-40 mM), but was strongly inhibited by nitrate and thiocyanate. SDS-PAGE separation of proteins present in the various membrane fractions was carried out. The apical membrane fraction alone contained a 28 kDa protein band that bound a monoclonal antibody specific for a 28 kDa peptide which was a component of the V-type ATPase from midgut of Manduca sexta and, in native gels, possessed ATPase activity which was also sensitive to both bafilomycin and NEM but not to azide or orthovanadate. Binding of the fluorescent monoclonal antibody was located at the apical boundary of the tubule cells. It was concluded that a V-type ATPase is present at the apical surface of Locusta Malpighian tubule cells and that it is involved in their secretory functioning.


Asunto(s)
Adenosina Trifosfatasas/metabolismo , Saltamontes/enzimología , Túbulos de Malpighi/enzimología , Adenosina Trifosfatasas/análisis , Adenosina Trifosfatasas/química , Animales , Transporte Biológico , Inmunohistoquímica , Masculino , Túbulos de Malpighi/fisiología
5.
Appl Environ Microbiol ; 64(2): 601-6, 1998 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-9464398

RESUMEN

Grazing of Echinopogon spp. by livestock in Australia has caused symptoms similar to those of perennial ryegrass staggers. We observed an endophytic fungus in the intercellular spaces of the leaves and seeds of New Zealand and Australian specimens of Echinopogon ovatus. Culture of surface-sterilized seeds from New Zealand specimens yielded a slow-growing fungus. An examination in which immunoblotting and an enzyme-linked immunosorbent assay (ELISA) were used indicated that E. ovatus plants from Australia and New Zealand were infected with fungi serologically related to Neotyphodium lolii (the endophyte of perennial ryegrass) and other Epichloe and Neotyphodium spp. endophytic in pooid grasses. No lolitrems (the indole-diterpenoids implicated as the causative agents of perennial ryegrass staggers), peramine analogs, or ergot alkaloids were detected in the infected specimens by high-performance liquid chromatography or ELISA. However, in endophyte-infected E. ovatus plants from New Zealand, analogs of the indole-diterpenoid paxilline (thought to be a biosynthetic precursor of the lolitrems and related tremorgens) were detected by ELISA, and N-formylloline was detected by gas chromatography. Endophyte-free specimens of New Zealand E. ovatus did not contain detectable paxilline analogs or lolines and were more palatable than infected specimens to adults of the pasture pest Listronotus bonariensis (Argentine stem weevil). Hyphae similar to those of the E. ovatus endophyte were also found in herbarium specimens of Echinopogon nutans var. major, Echinopogon intermedius, Echinopogon caespitosus, and Echinopogon cheeli. This appears to be the first time that an endophytic Neotyphodium species has been identified in grasses endemic to New Zealand or Australia.


Asunto(s)
Acremonium/aislamiento & purificación , Poaceae/microbiología , Acremonium/metabolismo , Acremonium/patogenicidad , Animales , Australia , Bovinos , Nueva Zelanda
6.
J Adv Nurs ; 20(3): 567-76, 1994 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-7963066

RESUMEN

This questionnaire study (n = 84) investigated several aspects of the attitudes of nurses of various grades and clinical settings towards termination of pregnancy (TOP). The majority of nurses had attitudes which lay within the undecided to positive range of the continuum, similar to findings from previous North American and British research. Very few were found to have extremely positive or negative attitudes. Several factors were significantly associated with negative attitudes towards TOP: frequency of involvement in TOP, length of time spent working on a gynaecology ward, religious affiliation, and ethnicity. Some discrepancy in nurses' attitudes was found with respect to both the length of a woman's gestation and the circumstances for which the procedure was being performed. In view of these findings, the implications for nursing practice are discussed.


PIP: In England, 84 nurses at a teaching hospital in London participated in a survey designed to examine their attitudes towards induced abortion and the effect these attitudes have on subsequent standards of care they provide and their own psychological well-being. 60.7% of attitude scores were within the undecided to positive range. More nurses had a strongly positive attitude score than a strongly negative score (15.5% vs. 2.3%). Nurses in the gynecology wards had much lower attitude scores than those in the medical and surgical wards (84 vs. 114 [p = 0.004] and 103.5 [p = 0.04], respectively). The longer the nurses worked in the gynecology ward, the lower their attitude score was ( 6 years = 89 vs. 104-107 for 0-5 years; p = 0.02), suggesting that their direct involvement in abortion puts them under constant stress. Nurses who had some religious affiliation had lower attitude scores than those who had no religious affiliation (94-104 vs. 112; p = 0.001). Roman Catholic nurses had a much lower attitude score than those of any other religion (94 vs. 97-104; p = 0.03). Nurses who practiced their religion regularly had much lower attitude scores than those who did not (p = 0.04). Caucasian nurses had higher attitude scores than did Afro-Caribbean nurses (105 vs. 99; p = 0.04). 57% of nurses said that their attitudes towards abortion changed with increasing gestational age (i.e., 12 weeks), generally in a negative direction. 13.1% of nurses considered abortion to be permissible under all circumstances. Circumstances identified most often by nurses to be permissible were risk to woman's physical/mental health (36.9%), fetal disorder (36.9%), and rape (33.3%). The most important implication of these findings is the possible effect of the negative attitudes among gynecology nurses on their well-being and on the women for whom they provide care. Gynecology nurses likely need more support to help them develop insights into their own beliefs and separate their attitudes from the needs of their patients.


Asunto(s)
Aborto Inducido , Actitud del Personal de Salud , Enfermeras y Enfermeros/psicología , Adulto , Etnicidad , Femenino , Edad Gestacional , Humanos , Masculino , Persona de Mediana Edad , Investigación en Evaluación de Enfermería , Embarazo , Pruebas Psicológicas , Psicometría , Religión , Encuestas y Cuestionarios
7.
Am J Physiol ; 266(5 Pt 2): R1551-61, 1994 May.
Artículo en Inglés | MEDLINE | ID: mdl-8203632

RESUMEN

Intracellular distributions of Na, K, Mg, Ca, Cl, P, and S were determined in type 1 Malpighian tubule cells of Locusta using X-ray microanalysis. K showed a gradient of increasing concentration from basal to apical surfaces. No other element showed this distribution. Na was below the detection limit. Three types of dark body were present in cytoplasm; one rich in Ca and P and two rich in K and P. Incubation in Rb-Ringer solution resulted in a dramatic fall in cellular K that was not completely replaced by Rb. The distribution of Rb mimicked that of K. Na levels were significantly increased, but the total intracellular monovalent metal concentration was less than in controls. Other elements were little affected. Rb replaced K in dark bodies. Tubules continued to secrete K-rich urine in Rb-Ringer solution even though intracellular [K] was low. Little Rb+ was secreted and Na+ secretion was unchanged. The possible role of dark bodies as a source of secreted K+ is discussed.


Asunto(s)
Saltamontes/fisiología , Túbulos de Malpighi/fisiología , Rubidio/metabolismo , Animales , Membrana Celular/metabolismo , Núcleo Celular/metabolismo , Citoplasma/metabolismo , Microanálisis por Sonda Electrónica/métodos , Liofilización , Túbulos de Malpighi/ultraestructura , Microscopía Electrónica , Microvellosidades/metabolismo , Potasio/metabolismo , Sodio/metabolismo
8.
J Adv Nurs ; 19(3): 566-71, 1994 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-8014318

RESUMEN

The increasing proportion of culturally diverse groups within the United Kingdom has meant that the issue of language barriers in the research situation must be addressed. The recruitment of respondents with English as a second language (ESL) to research studies is essential if their potentially unique and valid perspective is to be acknowledged. This can, however, pose several difficulties for the researcher which need to be recognized and addressed if valid data are to be collected. This paper outlines some of the challenges encountered in one study and describes strategies which were employed to meet these challenges.


Asunto(s)
Barreras de Comunicación , Entrevistas como Asunto/métodos , Lenguaje , Investigación en Enfermería/métodos , Humanos , Consentimiento Informado , Cinésica , Reproducibilidad de los Resultados , Muestreo , Reino Unido
9.
Burns ; 16(2): 118-22, 1990 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-2350405

RESUMEN

Lipid peroxides, formed as a consequence of oxygen free radical formation, are responsible for tissue damage in a great variety of pathological conditions including thermal injury. 'Cutaneous burn toxin', formed by application of heat to skin, is thought to be specific to the burn injury. It causes dose-dependent damage to mitochondrial and red cell membranes, and dose-dependent inhibition of interleukin-2-dependent growth of lymphocytes. The possibility that the toxicity of 'cutaneous burn toxin', a lipid-protein, is exerted through lipid peroxides, was examined by measuring the levels of both agents in plasmas of eight burn patients during the first week after their injury. It was observed that plasma lipid peroxides did not appear in parallel with absorption into the circulation of 'cutaneous burn toxin'. Lipid peroxide levels equally common to very low and very high burn toxin levels, were recorded. The pair of agents correlated negatively (r = -0.26) at a significance of only 0.1. In addition, isolated purified 'cutaneous burn toxin' contained no measurable lipid peroxide. No relationship was therefore demonstrated between plasma levels of 'cutaneous burn toxin' and lipid peroxides.


Asunto(s)
Quemaduras/metabolismo , Peróxidos Lipídicos/sangre , Piel/metabolismo , Toxinas Biológicas/sangre , Adulto , Anciano , Anciano de 80 o más Años , Quemaduras/sangre , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Masculino , Lípidos de la Membrana/sangre , Proteínas de la Membrana/sangre , Persona de Mediana Edad , Factores de Tiempo
10.
Med Decis Making ; 9(4): 272-84, 1989.
Artículo en Inglés | MEDLINE | ID: mdl-2796635

RESUMEN

The authors developed a decision tree-critiquing program (called BUNYAN) that identifies potential modeling errors in medical decision trees. The program's critiques are based on the structure of a decision problem, obtained from an abstract description specifying only the basic semantic categories of the model's components. A taxonomy of node and branch types supplies the primitive building blocks for representing decision trees. Bunyan detects potential problems in a model by matching general pattern expressions that refer to these primitives. A small set of general principles justifies critiquing rules that detect four categories of potential structural problems: impossible strategies, dominated strategies, unaccountable violations of symmetry, and omission of apparently reasonable strategies. Although critiquing based on structure alone has clear limitations, principled structural analysis constitutes the core of a methodology for reasoning about decision models.


Asunto(s)
Árboles de Decisión , Programas Informáticos
11.
Proc Natl Acad Sci U S A ; 80(14): 4522-6, 1983 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-6192435

RESUMEN

The origin and exact stage of differentiation of the neoplastic cells that comprise hairy cell leukemia have remained uncertain. As Ig heavy and light chain genes must both undergo a DNA rearrangement during B-cell development but rarely do so within other hematopoietic lineages, we examined these genes in this leukemia. The neoplastic cells of all eight cases demonstrated rearranged heavy and light chain genes and, in two cases examined, contained the corresponding mRNA for heavy and light chain Ig. Consistent with this B-cell genotype, all cases displayed cell surface HLA-DR and B-cell-associated antigens. Unexpectedly, all cases demonstrated cell surface Tac antigen, which previously had been restricted predominantly to select T-cell malignancies and activated T cells. Prior studies suggested that the anti-Tac monoclonal antibody recognized a peptide associated with the binding of interleukin 2 (T-cell growth factor) in such T cells. Immunoprecipitation with anti-Tac and NaDodSO4/polyacrylamide gel electrophoresis revealed an antigen on leukemic hairy cells with a Mr of 53,000-57,000, identical in size to the receptor on activated T cells. This apparent biphenotypic status might reflect a transformation-associated expression of the Tac antigen in this leukemia. Alternatively, hairy cell leukemia may be a malignancy of a unique stage of normal B-cell differentiation in which the Tac antigen is expressed.


Asunto(s)
Antígenos de Superficie/genética , Inmunoglobulinas/genética , Leucemia de Células Pilosas/inmunología , Anticuerpos Monoclonales , Antígenos de Diferenciación de Linfocitos B , Antígenos de Neoplasias/genética , ADN/genética , Enzimas de Restricción del ADN , Genes , Humanos , Complejo Mayor de Histocompatibilidad , ARN/genética , Linfocitos T/inmunología , Miembro 7 de la Superfamilia de Receptores de Factores de Necrosis Tumoral
12.
Transplantation ; 33(2): 184-90, 1982 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-6277055

RESUMEN

The pathogenic mechanisms responsible for the hypogammaglobulinemia that occurs in patients who have undergone bone marrow transplantation were studied using peripheral blood lymphocytes in an in vitro immunoglobulin biosynthesis assay. None of the nine marrow recipients between 2 and 15 months after transplantation produced normal amounts of IgG, IgA, or IgM in response to pokeweed mitogen (a T cell-dependent activator). However, three of these same patients responded to Epstein-Barr virus (a helper T cell- independent activator), suggesting that these three possessed responsive B cells. Cocultures of the marrow recipients' lymphocytes with lymphocytes from their respective donors or other normal subjects documented excessive suppressor cell activity in five cases. These suppressor cells frequently had profound activity (greater than 80% suppression of the immunoglobulin synthesis of cocultured normal cells), were predominantly radioresistant, and were T cells in the cases where analyzed. Helper T cell activity for immunoglobulin synthesis was not demonstrable in seven of the nine cases. In addition, four of the patients apparently possessed defective B cells. Although most patients had combined defects of several lymphocyte subpopulations, it appeared that either an isolated helper T cell or isolated B cell deficiency was sufficient to result in altered Ig synthesis. In this regard, two patients had demonstrable helper T cell defects with partially responsive B cells and no excessive suppressor activity. Interestingly, these two patients were experiencing a recurrence of their hypogammaglobulinemia following a period of normalized immunoglobulin levels. Thus, defects within all lymphocytic elements involved in the response and regulation of immunoglobulin synthesis were identified and may contribute to the humoral immunodeficiency which follows marrow transplantation.


Asunto(s)
Linfocitos B/inmunología , Inmunoglobulinas/biosíntesis , Linfocitos T Reguladores/inmunología , Linfocitos T/inmunología , Adolescente , Adulto , Trasplante de Médula Ósea , Separación Celular , Células Cultivadas , Niño , Herpesvirus Humano 4/inmunología , Humanos , Inmunoglobulina A/biosíntesis , Inmunoglobulina G/biosíntesis , Inmunoglobulina M/biosíntesis , Interleucina-1 , Activación de Linfocitos , Linfocinas/deficiencia , Persona de Mediana Edad , Mitógenos de Phytolacca americana/farmacología , Deficiencia de Proteína , Factores Supresores Inmunológicos
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