RESUMEN
Neuroimaging evidence suggests that the aging brain relies on a more distributed set of cortical regions than younger adults in order to maintain successful levels of performance during demanding cognitive tasks. However, it remains unclear how task demands give rise to this age-related expansion in cortical networks. To investigate this issue, functional magnetic resonance imaging was used to measure univariate activity, network connectivity, and cognitive performance in younger and older adults during a working memory (WM) task. Here, individuals performed a WM task in which they held letters online while reordering them alphabetically. WM load was titrated to obtain four individualized difficulty levels with different set sizes. Network integration-defined as the ratio of within-versus between-network connectivity-was linked to individual differences in WM capacity. The study yielded three main findings. First, as task difficulty increased, network integration decreased in younger adults, whereas it increased in older adults. Second, age-related increases in network integration were driven by increases in right hemisphere connectivity to both left and right cortical regions, a finding that helps to reconcile existing theories of compensatory recruitment in aging. Lastly, older adults with higher WM capacity demonstrated higher levels of network integration in the most difficult task condition. These results shed light on the mechanisms of age-related network reorganization by demonstrating that changes in network connectivity may act as an adaptive form of compensation, with older adults recruiting a more distributed cortical network as task demands increase.
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Envejecimiento/fisiología , Envejecimiento/psicología , Memoria a Corto Plazo/fisiología , Red Nerviosa/fisiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Mapeo Encefálico , Corteza Cerebral/diagnóstico por imagen , Corteza Cerebral/fisiología , Cognición/fisiología , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Red Nerviosa/diagnóstico por imagen , Neuroimagen , Desempeño Psicomotor/fisiología , Conducta Verbal , Adulto JovenRESUMEN
Purpose is to determine if Major League Baseball plays at risk for collisions have higher injury rates than typical base running plays. 2002-2011 Major League Baseball play data was obtained: non-force putouts by catcher at home plate (Catcher Tag Out), groundball force outs at 2(nd) base with less than 2 outs (Double Play Attempt), and the control play, outfield assisted non-force putouts of runners attempting to advance to 2(nd) or 3(rd) base (Outfield Assist 2(nd)/3(rd)). This list was cross-referenced with 2002-2011 disabled lists to see if an involved player went on the disabled list the day of or day after the play. An on-line search for each match determined if the injury was attributable to that play. Rate calculated per 1 000 plays, severity in days on disabled list. Injury rate and severity for Catcher Tag Out was 6.98 and 45.6 respectively, Double Play Attempt 0.42 and 41.3, Outfield Assist 2(nd/)3(rd) 1.56 and 47.0. Injury rate for Catcher Tag Out was higher (P = 0.03) than the control while Double Play Attempt trended lower (P = 0.05). There was no difference in severity. Catcher Tag Outs carry greater injury risk than typical base running plays. Major League Baseball should consider prohibiting base path collisions.
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Carrera/lesiones , Traumatismos en Atletas/epidemiología , Béisbol/lesiones , Humanos , Factores de Riesgo , Estados Unidos/epidemiologíaRESUMEN
The effects of increasing aflatoxin B1 concentration (0, 0.75, 1.5 mg/kg) on broilers with or without necrotic enteritis or virginiamycin were determined. In the 23-d study, 22 male Cobb 500 chicks per pen were allotted to 12 treatments (3 × 2 × 2 factorial arrangement) with 8 replications. Intestines of 5 birds per pen were examined for lesions on d 21. Birds were allowed to consume feed and water ad libitum. Aflatoxin was included in the diets from d 0. All birds received a 10× dose of coccidiosis vaccine on d 10. Pens of birds where necrotic enteritis was being induced were on Clostridium perfringens pathogen (CPP) contaminated litter from d 0. Aflatoxin decreased gain and feed intake and resulted in poorer feed:gain, increased mortality, and higher lesion scores. Inducing necrotic enteritis increased lesion scores and decreased feed intake and gain. Adding virginiamycin to the diets improved gain, feed intake, feed conversion, and decreased mortality. There was a 3-way interaction (aflatoxin × virginiamycin × CPP) on gain; increasing aflatoxin decreased gain and the effects of CPP and virginiamycin were dependent on aflatoxin concentration. In the absence of aflatoxin virginiamycin increased gain but was unable to prevent the growth suppression caused by CPP. At 0.75 mg/kg of aflatoxin virginiamycin no longer increased growth in non-CPP challenged birds but was able to increase growth in CPP-challenged birds. At the 1.5 mg/kg of aflatoxin concentration, virginiamycin increased gain in non-CPP-challenged birds but challenging birds with CPP had no effect on gain. Virginiamycin improved overall feed conversion with the greatest improvement at 1.5 mg/kg (aflatoxin × virginiamycin, P < 0.05). Aflatoxin increased lesion scores in unchallenged birds but not in challenged birds (aflatoxin × CPP, P < 0.001). Aflatoxin and necrotic enteritis decrease broiler performance and interact to decrease weight gain, virginiamycin helps improve gain in challenged birds at 0.75 mg/kg of aflatoxin, but not at 1.5 mg/kg of aflatoxin.
Asunto(s)
Aflatoxina B1/toxicidad , Pollos , Enteritis/veterinaria , Enfermedades de las Aves de Corral/tratamiento farmacológico , Virginiamicina/farmacología , Envejecimiento , Alimentación Animal/análisis , Animales , Ingestión de Alimentos , Enteritis/mortalidad , Enteritis/patología , Masculino , Enfermedades de las Aves de Corral/mortalidad , Enfermedades de las Aves de Corral/patologíaRESUMEN
Athletic injury risk in youth is known to be greater in organised sport, higher levels of competition, games, and tournaments, yet young athletes are often expected to participate in tournaments that involve multiple matches per day on consecutive days. In 2006 and 2008 injury rates were observed during a club youth soccer tournament that involved athletes aged 9-18 years playing three to four matches over two consecutive days, to determine if injury risk varied over the course of the event. The injury rate for day 1 was 7.91/1000 hours with a mean severity of 3.5 days missed versus a day 2 rate of 6.75 and severity of 2.3. The rate and severity for the first game in a day were 7.13 and 3.5 respectively compared to 7.9 and 2.5 for game 2. Further research is needed to determine if a high density match schedule increases injury risk for youth soccer players.
Asunto(s)
Fútbol/lesiones , Adolescente , Traumatismos en Atletas/epidemiología , Traumatismos en Atletas/patología , Niño , Femenino , Humanos , Masculino , North Carolina/epidemiología , Medición de Riesgo/métodos , Factores de Tiempo , Índices de Gravedad del TraumaRESUMEN
Working memory is the ability to perform mental operations on information that is stored in a flexible, limited capacity buffer. The ability to manipulate information in working memory is central to many aspects of human cognition, but also declines with healthy aging. Given the profound importance of such working memory manipulation abilities, there is a concerted effort towards developing approaches to improve them. The current study tested the capacity to enhance working memory manipulation with online repetitive transcranial magnetic stimulation in healthy young and older adults. Online high frequency (5Hz) repetitive transcranial magnetic stimulation was applied over the left dorsolateral prefrontal cortex to test the hypothesis that active repetitive transcranial magnetic stimulation would lead to significant improvements in memory recall accuracy compared to sham stimulation, and that these effects would be most pronounced in working memory manipulation conditions with the highest cognitive demand in both young and older adults. Repetitive transcranial magnetic stimulation was applied while participants were performing a delayed response alphabetization task with three individually-titrated levels of difficulty. The left dorsolateral prefrontal cortex was identified by combining electric field modeling to individualized functional magnetic resonance imaging activation maps and was targeted during the experiment using stereotactic neuronavigation with real-time robotic guidance, allowing optimal coil placement during the stimulation. As no accuracy differences were found between young and older adults, the results from both groups were collapsed. Subsequent analyses revealed that active stimulation significantly increased accuracy relative to sham stimulation, but only for the hardest condition. These results point towards further investigation of repetitive transcranial magnetic stimulation for memory enhancement focusing on high difficulty conditions as those most likely to exhibit benefits.
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Memoria a Corto Plazo/fisiología , Corteza Prefrontal/fisiología , Estimulación Magnética Transcraneal/métodos , Adulto , Anciano , Anciano de 80 o más Años , Humanos , Imagen por Resonancia Magnética , Persona de Mediana Edad , Pruebas Neuropsicológicas , Método Simple Ciego , Adulto JovenRESUMEN
Working memory (WM) is assumed to consist of a process that sustains memory representations in an active state (maintenance) and a process that operates on these activated representations (manipulation). We examined evidence for two distinct, concurrent cognitive functions supporting maintenance and manipulation abilities by testing brain activity as participants performed a WM alphabetization task. Maintenance was investigated by varying the number of letters held in WM and manipulation by varying the number of moves required to sort the list alphabetically. We found that both maintenance and manipulation demand had significant effects on behavior that were associated with different cortical regions: maintenance was associated with bilateral prefrontal and left parietal cortex, and manipulation with right parietal activity, a link that is consistent with the role of parietal cortex in symbolic computations. Both structural and functional architecture of these systems suggested that these cognitive functions are supported by two dissociable brain networks. Critically, maintenance and manipulation functional networks became increasingly segregated with increasing demand, an effect that was positively associated with individual WM ability. These results provide evidence that network segregation may act as a protective mechanism to enable successful performance under increasing WM demand.
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Memoria a Corto Plazo/fisiología , Red Nerviosa/fisiología , Lóbulo Parietal/fisiología , Adolescente , Adulto , Mapeo Encefálico , Femenino , Humanos , MasculinoRESUMEN
Lysine maize (Zea mays), LY038, was developed through the application of modern biotechnology to accumulate free Lys in the germ portion of maize grain and provide an alternative to direct addition of supplemental Lys to poultry diets. Maize LY038 x MON 810 was produced by conventional breeding of LY038 with MON 810, which provides the corn plant protection against feeding damage from the European corn borer. A 42-d broiler feeding study (10 pens of 10 male Cobb x Cobb 500 broilers/treatment) was conducted to compare the feeding value of grain from LY038 or LY038 x MON 810 to that of a conventional control (similar genetic background to the test maize) and 5 conventional maize hybrids. The LY038 and LY038 x MON 810 maize-based diets and control and conventional reference maize-based diets supplemented with l-Lys HCl were formulated to a Lys level below that required for optimal bird performance, whereas all other essential amino acids were present at levels, relative to Lys, above those required for optimal bird performance [1.05% and 0.90% total Lys (as-fed) for d 0 to 21 and d 21 to 42, respectively]. Total Lys level in control and reference maize-based diets without supplemental l-Lys HCl was formulated to be 0.079% lower than supplemented diets. Weight gain, feed efficiency, and carcass yield and composition of broilers fed diets containing LY038 or LY038 x MON 810 were not different (P > 0.05) from that of broilers fed l-Lys HCl-supplemented diets and were superior (P < or = 0.05) to that of broilers fed conventional maize diets without supplemental l-Lys HCl. Both broiler performance and carcass data demonstrate that the bioefficacy of the incremental Lys in LY038 or LY038 x MON 810 grain was not different from that of Lys in conventional maize diets supplemented with l-Lys HCl. Thus, LY038 and LY038 x MON 810 can be considered as wholesome as and more nutritious than conventional maize due to its higher-than-average Lys content.
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Alimentación Animal/análisis , Pollos/crecimiento & desarrollo , Dieta/veterinaria , Lisina , Zea mays/química , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Composición Corporal , Masculino , Zea mays/clasificaciónRESUMEN
Evaluating the impact of written materials is a means to enhance the effectiveness of patient education, yet few controlled studies of publications have been completed. In 1984, as a result of a needs assessment, the National Cancer Institute (NCI) developed and pretested the booklet "What Are Clinical Trials All About?" The booklet was designed to help cancer patients make informed decisions about participation in clinical trials, which are critical for improving cancer treatment. The booklet, which is currently available, has been used internationally as a model for communicating information on clinical trials. Since 1985, the booklet has been used by the Cancer Information Service (CIS) as an educational tool for answering questions from cancer patients about treatment and clinical trials. The CIS, which has traditionally assisted NCI in the development and testing of educational materials, was involved in the pretesting and particularly the posttesting of this booklet. The CIS regional offices at Fox Chase Cancer Center and Sylvester Comprehensive Cancer Center together with National Institutes of Health Clinical Center and North Memorial Medical Center conducted a posttest evaluation of the booklet's effectiveness for cancer patients. Two hospitals tested the booklet on patients who were eligible for a specific clinical trial, and two hospitals tested the booklet on patients who were theoretically eligible for a clinical trial (with a cancer site and stage for which a trial existed). Patients were randomly assigned: 203 experimental subjects received the booklet, and 194 control subjects were not given the booklet until after a 2-week posttest examining attitudes, knowledge, and beliefs about clinical trials.(ABSTRACT TRUNCATED AT 250 WORDS)
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Ensayos Clínicos como Asunto , Neoplasias/terapia , Educación del Paciente como Asunto , Actitud , Humanos , Neoplasias/psicología , Análisis de RegresiónRESUMEN
This paper identifies the potential applications of information-management technology in the Cancer Information Service national network and describes some innovations of individual network offices in each area. New applications are explored and recommendations are made for coordinating these efforts nationally.
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Servicios de Información/tendencias , Oncología Médica/educación , HumanosRESUMEN
Six months after complete spinal cord transection, regenerated descending motor axons can be found by electrophysiologic testing and can also be demonstrated anatomically using the Fink-Heimer/Nauta technique. Regeneration was found in all animals, treated or control, but statistically significant increased regeneration as measured by the Fink-Heimer/Nauta technique was found in animals treated with a single injection of 75 mg/kg of cyclophosphamide 24 hours after the original spinal cord transection. This result is similar to those of another study using the orthograde axonal transport of tritiated proline as a measure of axonal regeneration. The mode of action of cyclophosphamide may be by its immunosuppressive properties because this drug is most effective when administered 24 hours after cord transection, a time when its effects as an immunosuppressant would be maximal.
Asunto(s)
Axones/fisiología , Regeneración Nerviosa , Médula Espinal/fisiología , Animales , Antígenos , Axones/inmunología , Ciclofosfamida/farmacología , Electrofisiología , Femenino , Terapia de Inmunosupresión , Neuronas Motoras/fisiología , Regeneración Nerviosa/efectos de los fármacos , Potasio/sangre , Ratas , Médula Espinal/inmunologíaRESUMEN
The role of L3T4+ T lymphocytes in early primary infection with the metacestode of T. taeniaeformis was investigated by selective removal of these cells in vivo by parenteral injections with the rat monoclonal antibody (MAb) GK1.5 directed against the L3T4 molecule. Comparisons between treated and non-treated BALB/cByJ mice, normally resistant to infection with T. taeniaeformis, demonstrated that the treated mice had a greater percentage of viable parasites in the livers. Eosinophils were prominent in the region immediately surrounding parasite larvae in control mice, whereas treated mice showed virtually no eosinophil infiltration. Additionally, fewer tissue macrophages were evident near parasite larvae in the treatment group when compared to controls. The more susceptible C3H/HeDub strain mice demonstrated similar responses following treatment with the MAb, including diminished parasite killing and limited inflammatory cell infiltration. When C3H/HeDub mice were injected with the cytotoxic agent vinblastine sulfate, which has been shown to diminish Lyt-2+ suppressor cell activity, these mice remained unable to mount a strong local cellular response to the larval parasite. It is suggested that L3T4+ T lymphocytes play a crucial role in the innate resistance to T. taeniaeformis infection during the first 6 days post-infection. Effects seen following vinblastine treatment may be a result of drug-induced alterations in leukocyte chemotaxis, toxicity to other effector T cell populations, or a specific depletion of a functional Lyt-2+ T cell population that is required in addition to L3T4+ T cells for the expression of resistance to primary infection with T. taeniaeformis.
Asunto(s)
Linfocitos T Colaboradores-Inductores/inmunología , Teniasis/inmunología , Animales , Anticuerpos Monoclonales/inmunología , Femenino , Citometría de Flujo , Inmunidad Celular , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C3HRESUMEN
Activation of the alternative pathway of complement by T. taeniaeformis oncospheres and early stage metacestodes, although a factor in host defense against primary infection, does not directly lead to the killing of the parasite larvae observed prior to day 6 post-infection in innately resistant BALB/cByJ inbred mice. Immunogold labelling techniques clearly demonstrated tegument-associated C3 on in vitro-activated oncospheres incubated with non-immune mouse sera. However, C5, a protease necessary for the assembly of the membrane attack complex, was not detected. Early stage larvae cultured from in vitro-activated oncospheres escaped membrane damage and survived incubation in non-immune sera from both BALB/cByJ and taeniid-susceptible C3H/HeDub mice. Comparisons of cobra venom factor-treated and untreated C5-deficient B10.D2osn mice revealed no significant differences in parasite burden and local eosinophil infiltration at 6 days post-infection, suggesting that the terminal arm of the complement system is necessary for the previously reported role of complement in resistance to primary infection in BALB/cByJ and C3H/HeDub mice. An in vivo test of chemotaxis indicated that although both complement-intact mouse strains examined responded to intraperitoneal injections of inulin, there were lower numbers of eosinophils in C3H/HeDub mice than in BALB/cByJ mice, perhaps pointing to possible mouse strain differences in C5a generation/catabolism or eosinophil ability to respond to C5a. Lectin-binding studies showed an affinity of PNA for the exposed surface of taeniid oncospheres and 4-day post-infection metacestodes; however, binding of lectin to the carbohydrate moiety did not inhibit complement activation.
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Complemento C3/análisis , Vía Alternativa del Complemento , Taenia/inmunología , Teniasis/inmunología , Animales , Complemento C5/análisis , Femenino , Inmunohistoquímica , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C3HRESUMEN
If the shoulder-hand syndrome is left without special care, it may lead to severe painful disabilities of the upper extremity. Early recognition of the clinical signs and symptoms and aggressive total care are essential for successful treatment and for the prevention of severe flexion contractures of the hand and shoulder, especially in patients whose symptoms have developed after a cerebrovascular accident. An outline is given of the treatment modalities (corticosteroids, physiotherapy and mechanical devices) used at the Institute for Rehabilitation Medicine (NYU) for obtaining maximum function of the involved upper extremity.
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Distrofia Simpática Refleja/diagnóstico , Diagnóstico Diferencial , Humanos , Distrofia Simpática Refleja/terapia , Triamcinolona/uso terapéuticoRESUMEN
The tachyzoite of the human pathogen Toxoplasma gondii is morphologically indistinguishable from the proliferative stages of some other zoonotic coccidia, including Sarcocystis. To determine the identity of such coccidia obtained from human tissues and other sources, we compared riboprints (through restriction enzyme analysis of the polymerase chain reaction [PCR]-amplified small subunit rRNA gene) of the following protozoa: the RH and ts-4 strains of T. gondii, lines OH3 and S11, which are two recently isolated T. gondii-like parasites from Brazil, Neospora caninum, Sarcocystis species, and the malarial parasite Plasmodium berghei. In addition, the protozoan genomes were examined by PCR for homologs of surface antigen genes of T. gondii, and by Southern hybridization to the heterologous rRNA gene probe pSM 389. Strains OH3, S11, ts-4, and RH shared identical riboprints, and OH3, S11, and ts-4 have p22 and p30 surface antigen gene structures similar to RH. In contrast, riboprints for N. caninum and T. gondii differ with respect to Dde 1 sites, and moreover, their genomes vary significantly from one another at both the p22 and p30 gene loci. The riboprints of Sarcocystis and P. berghei differ markedly from T. gondii and N. caninum and from each other. Bam HI pSM 389 restriction fragment length polymorphisms differentiate ts-4 from RH, OH3, and S11. Our results confirm that OH3 and S11 are indeed T. gondii, but that N. caninum and T. gondii are likely to be separate species, thereby resolving previous uncertainties concerning the identity of these parasites. Together, the variation in riboprints and surface antigen gene structure reflects the phylogenetic diversity among these coccidia, and in addition, confirms the value of riboprinting in the identification of apicomplexan parasites such as T. gondii.
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Antígenos de Protozoos/genética , ARN Protozoario/genética , ARN Ribosómico/genética , Toxoplasma/aislamiento & purificación , Animales , Antígenos de Superficie/genética , Apicomplexa/genética , Apicomplexa/inmunología , Apicomplexa/aislamiento & purificación , Secuencia de Bases , Southern Blotting , ADN Protozoario/análisis , ADN Protozoario/química , ADN Ribosómico/análisis , ADN Ribosómico/química , Humanos , Datos de Secuencia Molecular , Hibridación de Ácido Nucleico , Plasmodium berghei/genética , Plasmodium berghei/inmunología , Plasmodium berghei/aislamiento & purificación , Reacción en Cadena de la Polimerasa , Mapeo Restrictivo , Sarcocystis/genética , Sarcocystis/inmunología , Sarcocystis/aislamiento & purificación , Porcinos , Toxoplasma/genética , Toxoplasma/inmunologíaRESUMEN
A small series of 58 patients who required amputation because of gangrene of the lower limb with nonreconstructable arteries at New York University Medical Center illustrates the manner in which application of some of these principles achieved primary healing of 78% in below-knee amputation and rehabilitation rate of as high as 90% using simple nonrigid dressings.
Asunto(s)
Amputación Quirúrgica , Arteriopatías Oclusivas/cirugía , Pierna/cirugía , Adulto , Anciano , Muñones de Amputación , Arteriopatías Oclusivas/rehabilitación , Angiopatías Diabéticas/cirugía , Femenino , Humanos , Rodilla , Pierna/irrigación sanguínea , Masculino , Persona de Mediana Edad , Cicatrización de HeridasRESUMEN
Using an accounting and political perspective, this paper explores how funding impacts on the formulation of research policy, through the governmental budgeting process and through the activity of corporate America, especially in the university arena. Initial discussion focuses on the public sector funding process, especially the concept of incrementalism in the budget process. Next, the political aspects of earmarking and pork-barreling are developed in the context of the university. Then, the relationships between government, corporate America and the university are briefly explored using a self-interest vs. public-interest model. Finally, the university's research and education contribution to the process was shown in order to prove that the corporate-university relationship was not entirely unilateral in nature. This paper does not offer a "correct solution"; to the problems presented. It does present a number of important issues and divergent opinions concerning the funding of research and development and encourages further research into this highly volitile area.
RESUMEN
A 5-year (1985-1989) retrospective immunohistochemical study was conducted using an avidin-biotin complex (ABC) immunoperoxidase method to demonstrate Sarcocystis neurona in histologically suspect cases of equine protozoal myeloencephalitis (EPM). Primary antibodies against S. neurona and S. cruzi were utilized for the ABC technique. The findings were compared with those from cases in which the organisms were detected by examination of hematoxylin and eosin (HE)-stained neuronal sections. HE-stained sections detected the presence of the organisms in 20% of the suspect cases; whereas the ABC technique confirmed the presence of S. neurona in 51% and 67% of the cases by S. neurona and S. cruzi antibodies, respectively. A review of clinical case histories showed that 21/47 (45%) of the EPM horses with parasites in the tissue sections had prior treatment with antiprotozoal drugs and/or steroids. Using the test results of S. neurona and S. cruzi as a standard reference, HE test sensitivity based on examination of up to 30 neuronal sections per case was only 25%, and test specificity was 91%.
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Encefalomielitis Equina/parasitología , Enfermedades de los Caballos/parasitología , Técnicas para Inmunoenzimas/veterinaria , Sarcocistosis/veterinaria , Animales , Anticuerpos Antiprotozoarios/análisis , Encefalomielitis Equina/patología , Enfermedades de los Caballos/patología , Caballos , Estudios Retrospectivos , Sarcocistosis/parasitología , Sarcocistosis/patologíaRESUMEN
Antigens of cultured Sarcocystis neurona merozoites were examined using immunoblot analysis. Blotted proteins were probed with S. cruzi, S. muris, and S. neurona antisera produced in rabbits, S. fayeri (pre- and post-infection) and S. neurona (pre- and post-inoculation) sera produced in horses, immune sera from 7 histologically confirmed cases of equine protozoal myeloencephalitis (EPM), and pre-suckle serum from a newborn foal. Eight proteins, 70, 24, 23.5, 22.5, 13, 11, 10.5, and 10 Kd, were detected only by S. neurona antiserum and/or immune serum from EPM-affected horses. Equine sera were titered by the indirect immunofluorescent antibody (IFA) method using air-dried, cultured S. neurona merozoites. Anti-Sarcocystis IFA titers were found in horses with or without EPM. Serum titers did not correspond to the number of specific bands recognized on immunoblots.
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Antígenos de Protozoos/análisis , Enfermedades de los Caballos , Sarcocystis/inmunología , Sarcocistosis/veterinaria , Animales , Antígenos de Protozoos/aislamiento & purificación , Bovinos , Células Cultivadas , Electroforesis en Gel de Poliacrilamida , Caballos , Immunoblotting , Peso Molecular , Sarcocystis/aislamiento & purificaciónRESUMEN
Ten 3-day-old chicks were submitted from a flock experiencing high mortality. Necropsy revealed lacrimation, diarrhea, pleural effusion, hemorrhage and ulceration of the proventriculus, and swollen, hemorrhagic livers. Numerous yellow granules were present in the crop. Assayed crop contents contained 39 ppm diazinon [O,O-diethyl O-(2-isopropyl-4-methyl-6-pyrimidyl)phosphorothioate]. The insecticide had been applied to the litter to control fire ants. The high mortality abated after new litter was added on top of the old litter. Diazinon toxicosis was traced to ingestion of diazinon-impregnated granules and was reproduced experimentally.
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Pollos , Diazinón/toxicidad , Intoxicación/veterinaria , Enfermedades de las Aves de Corral/patología , Envejecimiento , Animales , Autopsia , Relación Dosis-Respuesta a Droga , Intoxicación/mortalidad , Intoxicación/patología , Enfermedades de las Aves de Corral/mortalidadRESUMEN
Immunity to Toxoplasma gondii, as measured by oocyst shedding, was studied in cats. In 3 trials, 12 3-mo-old T. gondii-free cats were fed tissue cysts of the ME-49 strain of T. gondii. All cats shed T. gondii oocysts for approximately 1 wk starting 3-5 days after ingesting tissue cysts. One cat became ill because of toxoplasmic pneumonia and was killed 17 days after inoculation. The remaining cats remained clinically normal. Approximately 3 mo after primary infection, these 11 cats (immune) and 11 age-matched or littermate uninfected cats (nonimmune) were challenged orally with tissue cysts of the ME-49 strain. In trials 1 and 3, 1 immune and 1 nonimmune cat were killed at 36 hr, 60 hr, 5 days, and 12 days after challenge and the development of T. gondii in intestines was studied histologically; in trial 2, cats were killed at 36 hr, 60 hr, and 5 days only. None of the "immune" cats shed oocysts after challenge. Asexual T. gondii types were found at 36 and 60 hr and at 5 days, indicating partial development of T. gondii in the intestine of immune cats. There were no significant differences in lymphocyte CD4+/CD8+ from spleen, popliteal, and mesenteric lymph nodes of immune cats compared to nonimmune cats.