RESUMEN
There is a lack of evidence evaluating cryoprecipitate transfusion in severe postpartum haemorrhage. We performed a pilot cluster-randomised controlled trial to evaluate the feasibility of a trial on early cryoprecipitate delivery in severe postpartum haemorrhage. Pregnant women (>24 weeks gestation), actively bleeding within 24 h of delivery and who required at least one unit of red blood cells were eligible. Women declining transfusion in advance or with inherited clotting deficiencies were not eligible. Four UK hospitals were randomly allocated to deliver either the intervention (administration of two pools of cryoprecipitate within 90 min of first red blood cell unit requested plus standard care), or the control group treatment (standard care, where cryoprecipitate is administered later or not at all). The primary outcome was the proportion of women who received early cryoprecipitate (intervention) vs. standard care (control). Secondary outcomes included consent rates, acceptability of the intervention, safety outcomes and preliminary clinical outcome data to inform a definitive trial. Between March 2019 and January 2020, 199 participants were recruited; 19 refused consent, leaving 180 for analysis (110 in the intervention and 70 in the control group). Adherence to assigned treatment was 32% (95%CI 23-41%) in the intervention group vs. 81% (95%CI 70-90%) in the control group. The proportion of women receiving cryoprecipitate at any time-point was higher in the intervention (60%) vs. control (31%) groups; the former had fewer red blood cell transfusions at 24 h (mean difference -0.6 units, 95%CI -1.2 to 0); overall surgical procedures (odds ratio 0.6, 95%CI 0.3-1.1); and intensive care admissions (odds ratio 0.4, 95%CI 0.1-1.1). There was no increase in serious adverse or thrombotic events in the intervention group. Staff interviews showed that lack of awareness and uncertainty about study responsibilities contributed to lower adherence in the intervention group. We conclude that a full-scale trial may be feasible, provided that protocol revisions are put in place to establish clear lines of communication for ordering early cryoprecipitate in order to improve adherence. Preliminary clinical outcomes associated with cryoprecipitate administration are encouraging and merit further investigation.
Asunto(s)
Transfusión Sanguínea/métodos , Factor VIII/administración & dosificación , Fibrinógeno/administración & dosificación , Gravedad del Paciente , Hemorragia Posparto/diagnóstico , Hemorragia Posparto/terapia , Adulto , Análisis por Conglomerados , Femenino , Humanos , Proyectos Piloto , EmbarazoRESUMEN
Alternative hypotheses for order restrictions, such as umbrella or inverse umbrella (a.k.a tree) orderings, have been studied extensively in the literature, although less so when the studied response for each individual is the presence or absence of the event of interest. Two families of test statistics for solving the problem of testing against an umbrella or a tree ordering when the responses are binomial proportions are studied in this work and their asymptotic distributions are derived. A simulation study is conducted to compare the empirical power of some members of the derived families of test statistics with competing approaches. The methodology developed here was driven by an applied problem arising in stored products research where despite universal mortality in the case of doses of 1000 ppm of the insecticide phosphine, unexpected survival was noted at higher doses.
Asunto(s)
Insectos , Resistencia a los Insecticidas , Modelos Estadísticos , Animales , Simulación por Computador , FosfinasRESUMEN
Vaccination of dams with modified-live canine distemper virus (CDV) vaccines will elicit high concentrations of colostral antibody, that although vital for protection of the pup during the first weeks of life, can interfere with active vaccination against the virus. In the present study, 12 pups, 7-9 weeks of age, with maternally derived immunity to CDV, were vaccinated with a canarypox-vectored CDV vaccine. These pups were protected against intravenous challenge with CDV. Three littermate pups that were unvaccinated all developed clinical signs of infection after challenge, and two of these control pups died.
Asunto(s)
Animales Recién Nacidos/inmunología , Anticuerpos Antivirales/inmunología , Virus del Moquillo Canino/inmunología , Inmunidad Materno-Adquirida/inmunología , Inmunización/veterinaria , Animales , Virus de la Viruela de los Canarios/inmunología , Moquillo/inmunología , Moquillo/prevención & control , Perros , Femenino , Inmunización/métodos , Vacunación/métodos , Vacunación/veterinaria , Vacunas Virales/uso terapéuticoRESUMEN
The efficacy of a new recombinant FeLV vaccine (rFeLV), delivered transdermally via a needle-free delivery device was compared to that of an inactivated FeLV vaccine (FeLV-k), administered subcutaneously, with a conventional needle and syringe. Kittens were immunized with either rFeLV (0.25 ml, transdermal) or FeLV-k (1 ml, subcutaneous); or they were sham-vaccinated with physiologic saline (0.25 ml, transdermal). Two vaccinations were administered 21 days apart. Injection sites were monitored for any acute or subacute reactions relative to vaccine administration. Four weeks following the final vaccination, all cats were subject to oro-nasal FeLV challenge. Blood was collected for determination of FeLV antigenemia (p27) at weekly intervals beginning three weeks post-challenge. All of the vaccinated cats from both groups resisted FeLV challenge; and 90% of the control cats developed persistent FeLV antigenemia in response to challenge. No acute or persistent injection site reactions were observed. The rFeLV, delivered transdermally, provides protection against persistent FeLV antigenemia following a robust challenge that is equivalent to that of FeLV-k.
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Virus de la Leucemia Felina/inmunología , Leucemia Felina/prevención & control , Proteínas Oncogénicas de Retroviridae , Vacunación/veterinaria , Vacunas Virales , Administración Cutánea , Animales , Antígenos Virales/sangre , Gatos , Inyecciones Subcutáneas/veterinaria , Distribución Aleatoria , Proteínas Oncogénicas de Retroviridae/administración & dosificación , Proteínas Oncogénicas de Retroviridae/normas , Seguridad , Organismos Libres de Patógenos Específicos , Resultado del Tratamiento , Vacunas de Productos Inactivados/administración & dosificación , Vacunas de Productos Inactivados/normas , Vacunas Sintéticas/administración & dosificación , Vacunas Sintéticas/normas , Vacunas Virales/administración & dosificación , Vacunas Virales/normasRESUMEN
Several components of fitness were analysed in relation to the presence of a supernumerary chromosome segment (SCS) in two natural populations of the grasshopper Eyprepocnemis plorans, including clutch size, egg fertility, egg and embryo productivity and survivability from embryo to adult, and SCS transmission through males. The results have shown the absence of a significant relationship between SCS presence and these fitness components, with the single exception of egg fertility which decreases significantly in SCS females with mating shortage. This fertility decrease is thus expected to be relevant for the population dynamics of the SCS only in low-density populations, those in which it is difficult for females to find a male to copulate with before each egg-batch is ready to be laid. The analysis of the SCS transmission through males showed no significant differences between expected and observed SCS frequencies. The SCS polymorphism seems to be at a status close to neutrality in respect to fitness, but its slight disadvantage in transmission through females carrying B chromosomes predicts that the polymorphism should tend to disappear, unless SCS recurrent amplification, or another undiscovered force, counteracts this tendency.
Asunto(s)
Fertilidad/genética , Saltamontes/genética , Heterocromatina/ultraestructura , Análisis de Varianza , Animales , Femenino , Masculino , Modelos Genéticos , Modelos Estadísticos , Polimorfismo Genético , Dinámica PoblacionalRESUMEN
BACKGROUND: Lymphopenia has been described in patients with chronic renal failure (CRF). It is postulated that the decline in lymphocytes is due to accelerated apoptosis. We investigated whether dysregulation of programmed cell death plays a role in the immunodeficiency described in CRF. METHODS: Peripheral blood lymphocytes (PBL) from pre-dialysis uraemic patients (nHD) and haemodialysed patients (HD) were cultured with no stimulus for 96 h. Apoptosis of lymphocytes was measured by propidium iodide staining and flow cytometry. Expression of Fas and Bcl-2 was also analysed by flow cytometry. RESULTS: Peripheral blood B cells were significantly lower in pre-dialysis and haemodialysis uraemic patients compared to control. Lymphocytes from both groups of patients had a higher rate of apoptosis in vitro than those from healthy controls. This effect was more pronounced in B lymphocytes and a significant correlation between the B lymphopenia and the percentage of apoptotic B cells after 48 h of culture without stimulus was observed. The increased lymphocyte apoptosis in CRF was accompanied by a significantly lower in vitro Bcl-2 expression. However, Fas did not seem to play a role in spontaneous lymphocyte apoptosis in end-stage renal disease. CONCLUSIONS: Our data indicate that B lymphopenia in CRF may be partially attributed to an increased susceptibility to cell death by apoptosis that is associated with a decreased expression of Bcl-2.
Asunto(s)
Apoptosis , Linfocitos B/patología , Fallo Renal Crónico/sangre , Linfopenia/sangre , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Uremia/sangre , Adolescente , Adulto , Anciano , Linfocitos B/inmunología , Linfocitos B/metabolismo , Biomarcadores , Células Cultivadas , Femenino , Citometría de Flujo , Humanos , Fallo Renal Crónico/complicaciones , Fallo Renal Crónico/patología , Fallo Renal Crónico/terapia , Recuento de Linfocitos , Linfopenia/etiología , Linfopenia/patología , Masculino , Persona de Mediana Edad , Diálisis Renal , Linfocitos T/inmunología , Linfocitos T/metabolismo , Linfocitos T/patología , Uremia/complicaciones , Uremia/patología , Uremia/terapia , Receptor fas/metabolismoRESUMEN
OBJECTIVES: To evaluate the safety and efficacy of a live canarypox virus recombinant-canine distemper virus (CDV) combination vaccine against virulent CDV challenge exposure, and to document lack of interference among the other modified-live virus (MLV) components. ANIMALS: 33 specific-pathogen-free (SPF) Beagle pups (7 to 10 weeks old). PROCEDURE: A canarypox virus recombinant-CDV combination vaccine was tested for safety and efficacy along with MLV components (canine adenovirus type 2, canine coronavirus, canine parainfluenza virus, and canine parvovirus) in 26 SPF Beagle pups. The combination vaccine was rehydrated with either Leptospira canicola-L icterohaemorrhagiae combination bacterin (vaccine 1) or sterile diluent (vaccine 2). An additional group of 7 seronegative SPF pups received the control MLV components devoid of the combination vaccine (vaccine 3). Two vaccinations were administered 21 days apart, either IM or SC. The dose of the combination vaccine used to inoculate these pups was 40 times lower than the recommended commercial dose. At 21 days after the booster vaccination, all pups were challenge exposed with a virulent CDV strain, then were observed for 21 days to record morbidity and mortality. RESULTS: Adverse local or generalized reactions were not induced by vaccinations. All vaccinates seroconverted to CDV. Serum antibody titers to MLV components were not different, with or without inclusion of the combination vaccine. After challenge exposure, morbidity and mortality in vaccinates were 0% (0/26); in control dogs, values were 100% morbidity and 86% mortality (6/7). Brain impression smear slides made from all dogs that did not survive challenge exposure were CDV positive by use of a direct fluorescein isothiocyanate method. CONCLUSIONS: The canarypox virus-CDV combination vaccine, administered SC or IM, is a safe product that elicits CDV seroconversion, does not interfere with other vaccine components, and protects vaccinated pups against virulent CDV challenge exposure.
Asunto(s)
Avipoxvirus/inmunología , Virus del Moquillo Canino/inmunología , Moquillo/prevención & control , Vacunas Sintéticas , Vacunas Virales , Animales , Anticuerpos Antivirales/sangre , Moquillo/epidemiología , Moquillo/mortalidad , Perros , Femenino , Hemaglutininas Virales/inmunología , Incidencia , Masculino , Morbilidad , Proteínas Recombinantes de Fusión/inmunologíaRESUMEN
Effects of the B chromosome polymorphism of the grasshopper Eyprepocnemis plorans were analyzed in two natural populations. Postmating sexual selection, female fertility, and survival were studied. The B chromosome lacks drive and has no detectable effects on fitness. A neutral B cannot invade a population and establish a polymorphism, but the confidence limits on our estimates cannot exclude the possibility that the polymorphism is maintained by a balance between weak drive and weak selection against individuals with two and three B's. However, other lines of evidence favor the following model of the dynamics of the B in E. plorans. In a newly invaded population, the B has substantial drive, but the evolution of drive suppressor genes in the A chromosomes neutralizes the B drive so that it becomes near-neutral and begins a random walk toward extinction by stochastic loss. Because the B is common by the time drive disappears, the random walk is likely to continue for a long time. If in the course of the random walk a variant B with greater drive appears, then it will displace the original variant, and a new cycle of drive suppression and drift to extinction occurs. A simulation model of this process suggested that the mean time to extinction is proportional to the two-thirds power of the population size; it is much less affected by subpopulation size or the number of populations in a subdivided population.
RESUMEN
Interannual evolution of a polymorphism for a supernumerary segment in the smallest autosome of the grasshopper Eyprepocnemis plorans has been analysed in two natural populations. The polymorphism seemed to be stable in both populations, despite its undertransmission through heterozygous females carrying B chromosomes. Analyses of the effects of the extra segment on mating behaviour failed to show differential mating success in any sex or consistent effects on mating pattern. These results are discussed in relation to the maintenance of this polymorphism in natural populations.
RESUMEN
Seventeen controlled crosses in which the mitotically unstable B chromosome of Locusta migratoria was carried by one parent only have provided evidence that B chromosomes are significantly eliminated during sexual transmission in males, at a mean rate that almost counteracts the premeiotic accumulation derived from mitotic instability during germ line development. On the other hand, B chromosomes are significantly accumulated in females, presumably by their preferential migration to the secondary oocyte during the first meiotic division. These results substantially change the current knowledge about this B chromosome system, because the main B accumulation occurs in females and not in males, as was hitherto thought. Furthermore, this case shows that the maintenance of a single B system in natural populations may be the result of many different forces and mechanisms acting for and against B chromosomes.
RESUMEN
The transmission ratio (ks) for a supernumerary chromosome segment was studied in a total of 54 heterozygous females collected from two Spanish natural populations of the grasshopper Eyprepocnemis plorans. Our analysis clearly demonstrated that ks is negatively dependent on the number of B chromosomes in the female. The possible mechanisms by which B chromosomes may cause undertransmission of the supernumerary segment, and the implications of this phenomenon for the maintenance of this extra chromosome segment, are discussed.
RESUMEN
A single female of Locusta migratoria was found to be heterozygous for a supernumerary heterochromatic segment distally located on the M6 autosome close to its nucleolus organiser region (NOR). Reactions to several chromosome banding techniques revealed its heterochromatic nature and its composition of GC-rich DNA sequences and likewise the NORs in this species. This suggests an origin for the extra segment by amplification of GC-rich DNA sequences contained in the distal NOR of the M6 chromosome, which is reinforced by the observation that the NOR of segmented M6 chromosomes produced the larger nucleolus in embryo prophase cells, such as would be expected from the presence of rRNA genes in the extra segment. No accumulation mechanism was detected in this female after analyzing the 213 embryo offspring produced, but an increase in the number of nucleoli per interphase nucleus was noted in heterozygous embryos in respect to standard homozygous ones.