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1.
Int J STEM Educ ; 11(1): 14, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38404757

RESUMO

Background: Large introductory lecture courses are frequently post-secondary students' first formal interaction with science, technology, engineering, and mathematics (STEM) disciplines. Grade outcomes in these courses are often disparate across student populations, which, in turn, has implications for student retention. This study positions such disparities as a manifestation of systemic inequities along the dimensions of sex, race/ethnicity, income, and first-generation status and investigates the extent to which they are similar across peer institutions. Results: We examined grade outcomes in a selected set of early STEM courses across six large, public, research-intensive universities in the United States over ten years. In this sample of more than 200,000 STEM course enrollments, we find that course grade benefits increase significantly with the number of systemic advantages students possess at all six institutions. The observed trends in academic outcomes versus advantage are strikingly similar across universities despite the fact that we did not control for differences in grading practices, contexts, and instructor and student populations. The findings are concerning given that these courses are often students' first post-secondary STEM experiences. Conclusions: STEM course grades are typically lower than those in other disciplines; students taking them often pay grade penalties. The systemic advantages some student groups experience are correlated with significant reductions in these grade penalties at all six institutions. The consistency of these findings across institutions and courses supports the claim that inequities in STEM education are a systemic problem, driven by factors that go beyond specific courses or individual institutions. Our work provides a basis for the exploration of contexts where inequities are exacerbated or reduced and can be used to advocate for structural change within STEM education. To cultivate more equitable learning environments, we must reckon with how pervasive structural barriers in STEM courses negatively shape the experiences of marginalized students. Supplementary Information: The online version contains supplementary material available at 10.1186/s40594-024-00474-7.

2.
PLoS One ; 19(1): e0296389, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38198497

RESUMO

BACKGROUND: Students' sense of belonging in college-an individual's feelings of contentment, mattering, importance, and "finding one's place" in a social setting-can influence choice of major and career trajectory. We contribute to the belongingness literature through a mixed methods intersectional study of students attending a STEM-focused public university we call Meadow State University (MSU). We assess the potential for students' intersecting social identities to differentially influence their experiences with intersectional oppression-subjection to multiple systems of oppression due to simultaneous membership in more than one marginalized group-that, in turn, may influence their college pathways. In addition, we explore whether intersectional differences affect sense of belonging differently in STEM and non-STEM majors. We employ a mixed-methods approach, informed by critical quantitative methods and in-depth interviews. We utilize quantitative institutional data measuring college satisfaction, expressed as "willingness to return" to the same university, for over 3,000 students during two academic years (2013-14 and 2016-17). Survey data explores college satisfaction as an indicator of intersectional differences in student experiences. Then, we analyze 37 in-depth interviews, collected between 2014-2016 at the same institution, to further contextualize the intersectional variation suggested by survey results. RESULTS: Willingness to return is influenced by major, as well as academic, social, and campus belonging. Moreover, the extent to which these factors affected outcomes additionally varied by race/ethnicity, gender, family income, other background factors, and the ways these factors may intersect. Important components of academic belonging included faculty-student interactions, perceptions of academic support, and a privileging of STEM degree programs and students over non-STEM students and their degree programs at MSU. Faculty responsiveness and high impact practices like internships played an important role, particularly in STEM programs. Taken together, our findings demonstrate that, particularly for students of color and those subject to intersectional oppression due to multiple marginalized identities, satisfaction with academics did not always outweigh deficiencies in other areas of campus life shaping belongingness. CONCLUSIONS: Our mixed-methods approach contributes insights into how and why students' background, individual choices, and institutional practices concurrently-and intersectionally-influence their ability to form a sense of belonging on campus. Structural changes are required to end practices that support intersecting systems of oppression by favoring White, upper-income men as the "default" STEM students in the U.S. Our research supports growing evidence that institutions must actively build models of inclusion for underrepresented and marginalized groups that address inequitable and unjust practices, providing transformative mentoring and educational guidance that attends to intersectional oppression, in order to effectively support the next generation of women and scholars of color.


Assuntos
Enquadramento Interseccional , Instituições Acadêmicas , Masculino , Humanos , Feminino , Universidades , Estudantes , Etnicidade
3.
CBE Life Sci Educ ; 21(1): es1, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35100005

RESUMO

The recent anti-racist movements in the United States have inspired a national call for more research on the experiences of racially marginalized and minoritized students in science, technology, engineering, and mathematics (STEM) fields. As researchers focused on promoting diversity, equity, and inclusion, we contend that STEM education must, as a discipline, grapple with how analytic approaches may not fully support equity efforts. We discuss how researchers and educational practitioners should more critically approach STEM equity analyses and why modifying our approaches matters for STEM equity goals. Engaging with equity as a process rather than a static goal, we provide a primer of reflective questions to assist researchers with framing, analysis, and interpretation of student-level data frequently used to identify disparities and assess course-level and programmatic interventions. This guidance can inform analyses conducted by campus units such as departments and programs, but also across universities and the scientific community to enhance how we understand and address systemic inequity in STEM fields.


Assuntos
Engenharia , Estudantes , Engenharia/educação , Humanos , Matemática , Tecnologia/educação , Universidades
4.
Ethn Racial Stud ; 44(5): 806-818, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34035554

RESUMO

The present study used data from the American Trends Panel to examine the interplay between the perceived COVID-19 health threat, discriminatory beliefs in medical settings, and psychological distress among Black Americans. We measured psychological distress as an average of five items modified from two established scales and used self-reports of perceived COVID-19 health threat and beliefs about discrimination in medical settings as focal predictors. Ordinary least squares regression was used to examine these relationships. Holding all else constant, we found that perceived COVID-19 health threat and the belief that Black Americans face racial discrimination in medical settings were both positively and significantly associated with higher levels of psychological distress. We also found a significant perceived COVID-19 health threat by belief about discrimination in medical settings interaction in the full model. Future studies should assess how these relationships vary across age groups and over time.

5.
Biodemography Soc Biol ; 62(3): 281-299, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27809658

RESUMO

As the social sciences expand their involvement in genetic and genomic research, more information is needed to understand how theoretical concepts are applied to genetic data found in social surveys. Given the layers of complexity of studying race in relation to genetics and genomics, it is important to identify the varying approaches used to discuss and operationalize race and identity by social scientists. The present study explores how social scientists have used race, ethnicity, and ancestry in studies published in four social science journals from 2000 to 2014. We identify not only how race, ethnicity, and ancestry are classified and conceptualized in this growing area of research, but also how these concepts are incorporated into the methodology and presentation of results, all of which structure the discussion of race, identity, and inequality. This research indicates the slippage between concepts, classifications, and their use by social scientists in their genetics-related research. The current study can assist social scientists with clarifying their use and interpretations of race and ethnicity with the incorporation of genetic data, while limiting possible misinterpretations of the complexities of the connection between genetics and the social world.


Assuntos
Grupos Raciais/genética , Ciências Sociais/métodos , Humanos
6.
Am J Infect Control ; 43(2): 121-6, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25480448

RESUMO

BACKGROUND: Biomedical research journals are important because peer reviewed research is viewed as more legitimate and trustworthy than non-peer reviewed work. Therefore, it is important to know how knowledge transmitted through academic biomedical journals is produced. This article asks if some organizations are more likely to produce research than others and if organizational setting is linked with an article's impact, as measured by citation counts. METHODS: Using research on methicillin-resistant Staphylococcus aureus (MRSA) as a case study, we examined the role that hospitals, universities, public health agencies, and other organizations have in shaping an emerging research area. We collected public data on the organizational affiliations of researchers who authored 1,721 articles in general interest and selected specialty journals. RESULTS: MRSA research appears to have evolved in stages that require the participation of different types of organizations. Additionally, our analyses indicate that an author's organizational affiliation predicts citation counts, even when controlling for other factors. CONCLUSION: Organizations vary greatly in their ability to produce research, and this should be taken into account by those who manage or award funds to research organizations.


Assuntos
Staphylococcus aureus Resistente à Meticilina , Publicações Periódicas como Assunto/normas , Pesquisa/história , Infecções Estafilocócicas/transmissão , Autoria , História do Século XX , História do Século XXI , Humanos , Editoração , Infecções Estafilocócicas/microbiologia
7.
J Pan Afr Stud ; 7(1): 61-73, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29710883

RESUMO

A holistic graduate education can impart not just tools and knowledge, but critical positioning to fulfill many of the original missions of Africana Studies programs set forth in the 1960s and 1970s. As an interdisciplinary field with many approaches to examining the African Diaspora, the methodological training of graduate students can vary across graduate programs. Although taking qualitative methods courses are often required of graduate students in Africana Studies programs, and these programs offer such courses, rarely if ever are graduate students in these programs required to take quantitative methods courses, let alone have these courses offered in-house. These courses can offer Africana Studies graduate students new tools for their own research, but more importantly, improve their knowledge of quantitative research of diasporic communities. These tools and knowledge can assist with identifying flawed arguments about African-descended communities and their members. This article explores the importance of requiring and offering critical quantitative methods courses in graduate programs in Africana Studies, and discusses the methods requirements of one graduate program in the field as an example of more rigorous training that other programs could offer graduate students.

8.
Rev Sci Instrum ; 83(12): 125106, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23278025

RESUMO

Instrumented indentation is a widely used technique to study the mechanical behavior of materials at small length scales. Mechanical tests of bulk materials, microscopic, and spectroscopic studies may be conducted to complement indentation and enable the determination of the kinetics and physics involved in the mechanical deformation of materials at the crystallographic and molecular level, e.g., strain build-up in crystal lattices, phase transformations, and changes in crystallinity or orientation. However, many of these phenomena occurring during indentation can only be observed in their entirety and analyzed in depth under in situ conditions. This paper describes the design, calibration, and operation of an indentation device that is coupled with a Raman microscope to conduct in situ spectroscopic and optical analysis of mechanically deformed regions of Raman-active, transparent bulk material, thin films or fibers under contact loading. The capabilities of the presented device are demonstrated by in situ studies of the indentation-induced phase transformations of Si thin films and modifications of molecular conformations in high density polyethylene films.


Assuntos
Teste de Materiais/instrumentação , Fenômenos Mecânicos , Fenômenos Ópticos , Análise Espectral Raman/instrumentação , Calibragem , Desenho de Equipamento , Lasers , Microscopia , Polietileno/química , Silício/química
9.
J Res Natl Inst Stand Technol ; 109(5): 465-77, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-27366626

RESUMO

A high-throughput (high throughput is the ability to process large numbers of samples) and companion informatics system has been developed and implemented. High throughput is defined as the ability to autonomously evaluate large numbers of samples, while an informatics system provides the software control of the physical devices, in addition to the organization and storage of the generated electronic data. This high throughput system includes both an ultra-violet and visible light spectrometer (UV-Vis) and a Fourier transform infrared spectrometer (FTIR) integrated with a multi sample positioning table. This method is designed to quantify changes in polymeric materials occurring from controlled temperature, humidity and high flux UV exposures. The integration of the software control of these analytical instruments within a single computer system is presented. Challenges in enhancing the system to include additional analytical devices are discussed.

10.
J Natl Med Assoc ; 93(3 Suppl): 11S-34S, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12653395

RESUMO

Racism in medicine, a problem with roots over 2,500 years old, is a historical continuum that continuously affects African-American health and the way they receive healthcare. Racism is, at least in part, responsible for the fact African Americans, since arriving as slaves, have had the worst health care, the worst health status, and the worst health outcome of any racial or ethnic group in the U.S. Many famous doctors, philosophers, and scientists of each historical era were involved in creating and perpetuating racial inferiority mythology and stereotypes. Such theories were routinely taught in U.S. medical schools in the 18th, 19th, and first half of the 20th centuries. The conceptualization of race moved from the biological to the sociological sphere with the march of science. The atmosphere created by racial inferiority theories and stereotypes, 246 years of black chattel slavery, along with biased educational processes, almost inevitably led to medical and scientific abuse, unethical experimentation, and overutilization of African-Americans as subjects for teaching and training purposes.


Assuntos
Negro ou Afro-Americano , Medicina Clínica/história , Atenção à Saúde/história , Preconceito , Medicina Clínica/normas , Atenção à Saúde/ética , Atenção à Saúde/normas , Ética Clínica , História do Século XIX , História do Século XX , Experimentação Humana/ética , Humanos , Estereotipagem , Estados Unidos
11.
J Natl Med Assoc ; 93(3 Suppl): 35S-54S, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12653396

RESUMO

Based on the latest available data, African Americans are faced with persistent, or worsening, wide and deep, race-based health disparities compared to the white or general population as we enter the new millennium. These disparities are a 382-year continuum. There have been two periods of health reform specifically addressing the correction of race-based health disparities. The first period (1865-1872) was linked to Freedmen's Bureau legislation and the second (1965-1975) was a part of the Black Civil Rights Movement. Both had dramatic and positive effects on black health status and outcome, but were discontinued too soon to correct the "slave health deficit." Although African-American health status and outcome is slowly improving, black health has generally stagnated or deteriorated compared to whites since 1980. There is a compelling need for a third period of health reform accompanied by a cultural competence movement to address and correct persistent, often worsening, race-based health disparities.


Assuntos
Negro ou Afro-Americano/estatística & dados numéricos , Causas de Morte , Nível de Saúde , Mortalidade/tendências , Avaliação de Resultados em Cuidados de Saúde , Preconceito , Feminino , Acessibilidade aos Serviços de Saúde/normas , Acessibilidade aos Serviços de Saúde/tendências , Indicadores Básicos de Saúde , Humanos , Masculino , Estudos Retrospectivos , Fatores de Risco , Fatores Socioeconômicos , Estados Unidos/epidemiologia , População Branca/estatística & dados numéricos
12.
J Sex Marital Ther ; 26(2): 133-40, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10782445

RESUMO

Ninety-two outpatients (31 women, 61 men) who were treated with oral sildenafil for psychotropic-induced sexual dysfunction (PISD) completed ratings of their sexual functioning pre- and posttreatment. Both women and men reported significant improvements (p = .001) in all domains of sexual functioning, with 88% reporting improvement in overall sexual satisfaction. Significant improvements were reported regardless of psychotropic medication type. However, patients taking selective serotonin re-uptake inhibitors reported less improvement in arousal, libido, and overall sexual satisfaction than did other patients, whereas patients taking benzodiazepines reported significantly more improvement in libido and overall sexual satisfaction. Oral sildenafil may be an effective treatment for PISD.


Assuntos
Inibidores de Fosfodiesterase/uso terapêutico , Piperazinas/uso terapêutico , Psicotrópicos/efeitos adversos , Disfunções Sexuais Psicogênicas/induzido quimicamente , Adulto , Nível de Alerta/efeitos dos fármacos , Feminino , Humanos , Libido/efeitos dos fármacos , Masculino , Satisfação Pessoal , Inibidores de Fosfodiesterase/farmacologia , Piperazinas/farmacologia , Purinas , Estudos Retrospectivos , Fatores Sexuais , Citrato de Sildenafila , Sulfonas
13.
Am J Primatol ; 48(2): 135-51, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10333433

RESUMO

An enzyme-linked immunosorbent assay (ELISA) for human urinary beta follicle-stimulating hormone (FSH) subunit was validated for use in the laboratory macaque (Macaca mulatta and Macaca fasicularis). This ELISA is based on the dissociation of the FSH heterodimer in urine and the subsequent measurement of the beta subunit as a representation of total urinary FSH. This assay was then used to describe the gonadotropin escape following ovarian senescence in post-menopausal macaques. In addition, the assay was used to observe the impact of an acute stressor on the pituitary-gonadal axis and how the impact of this stressor varies when experienced at different stages of the menstrual cycle. The study design involved the measurement of ovarian steroids and FSH in urine collected daily during a period of time when animals experienced a well-defined event on two occasions consisting of capture, restraint, and anesthesia. This unique study design was made possible by the ability to monitor both ovarian and pituitary function in the absence of confounding daily captures and restraint for blood collection. There was a high correlation between urinary FSH measured in macaques with the beta FSH subunit ELISA and serum FSH measured in paired blood samples by radioimmunoassay (n=39, r2=0.878, P<0.001) and the composite urinary FSH profile obtained from normal, premenopausal macaques exhibited the expected dynamics with a transient rise of FSH during the luteal-follicular transition as well as an acute rise of FSH at mid-cycle. This pattern was lost in castrate and post-menopausal monkeys in which FSH levels were significantly increased (P<0.0001) above those of intact males and young females, respectively. In the stress study, we found that stressors occurring during the luteal-follicular transition not only resulted in acute perturbations of FSH but also led to abnormalities in the subsequent menstrual cycle in 50% of the cases.


Assuntos
Hormônio Foliculoestimulante/urina , Macaca fascicularis/fisiologia , Macaca mulatta/fisiologia , Menstruação/fisiologia , Estresse Psicológico , Animais , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Menopausa/fisiologia
14.
West J Med ; 170(1): 53-4, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18751125
15.
J Clin Endocrinol Metab ; 83(8): 2849-54, 1998 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9709958

RESUMO

Inhibins are glycoprotein members of the transforming growth factor-beta family that have been implicated in the control of spermatogenesis by exerting a negative feedback on FSH secretion. In addition, locally produced inhibins may play a role in paracrine regulation of testicular function. Immunoassays were used to measure the two biologically active dimeric forms of inhibin (inhibin A and B) in serum, seminal plasma, and urine. To better define their actions, inhibins were measured in the male during infancy, sexual maturation, and senescence. Inhibin B but not A was measurable in the serum of male newborns, infants, children, and adults. In adult males, measurable levels of inhibin B were detected in the seminal plasma but not the urine. The circulating levels of inhibin B increased shortly after birth and peaked at 4-12 months of age (210 +/- 31 pg/mL). The concentration measured in the serum then decreased to a low of 81 +/- 12 pg/mL of inhibin B from 3-9 yr of age followed by a gradual increase beginning with the onset of puberty and reaching another peak of 167 +/- 20 pg/mL in males who were 20-30 yr of age. Inhibin B levels then gradually declined with increasing age up through 90 yr of age. Serum levels of gonadotropins and total testosterone production were also measured in these same males. There was a brief increase in the gonadotropins (FSH and LH) during the few months of postnatal development, followed by a decrease to basal levels until the onset of puberty at 10-14 yr of age. Testosterone was also increased in the serum of infants from day 1 through 12 months of age, which decreased in young children but increased again following the elevation of gonadotropins during puberty. In adults aged 20-90 yr, serum levels of inhibin B were inversely proportional to levels of FSH but not LH or testosterone. In males in which a semen analysis was performed, those males with normal semen analysis had a significantly higher inhibin B levels, sperm production, and lower FSH levels than males with either oligospermia or nonobstructive azoospermia. The levels of Inhibin B found in circulation were a good marker for testicular function and could be useful in the diagnosis of patients with semen abnormalities or a complete absence of spermatogenesis. Because this glycoprotein is secreted in high amounts in the prepubertal testis up to 3 yr of age, inhibin B could potentially be used as a marker in the diagnosis of cryptorchidism and precocious puberty.


Assuntos
Envelhecimento/sangue , Dimerização , Inibinas/sangue , Adolescente , Adulto , Criança , Pré-Escolar , Hormônio Foliculoestimulante/sangue , Humanos , Recém-Nascido , Infertilidade Masculina/sangue , Inibinas/análise , Inibinas/fisiologia , Hormônio Luteinizante/sangue , Masculino , Pessoa de Meia-Idade , Puberdade , Sêmen/química , Espermatogênese , Testosterona/sangue
16.
West J Med ; 169(1): 56-7, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18751112
17.
J Am Coll Cardiol ; 30(1): 125-30, 1997 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9207632

RESUMO

OBJECTIVES: We sought to determine the effects of nicotine patch therapy, when used to promote smoking cessation, on myocardial ischemia in patients with coronary artery disease. BACKGROUND: Nicotine patches substantially increase quit rates among cigarette smokers, but their safety in patients with myocardial ischemia who are attempting to quit smoking is unknown. METHODS: This is a prospective study using exercise thallium-201 single-photon emission computed tomography (SPECT) to assess serial changes in the total and ischemic myocardial perfusion defect size at baseline while patients were smoking and during treatment with 14- and 21-mg nicotine patches. Entry criteria required that patients 1) smoked > or = 1 pack of cigarettes per day; 2) had known coronary artery disease; and 3) had myocardial ischemia (i.e., > or = 5% reversible perfusion defect) on SPECT. All patients performed symptom-limited treadmill exercise, and the baseline SPECT study served as its own control. We interpreted and computer quantified the SPECT images with no knowledge of the testing sequence. RESULTS: Thirty-six of the 40 enrolled patients had exercise SPECT at baseline and during treatment with at least 14-mg nicotine patches. These patients had an initial perfusion defect size of 17.5 +/- 10.6% while smoking an average of 31 +/- 11 cigarettes per day for 40 +/- 12 years. A significant reduction in the total perfusion defect size (p < 0.001) was observed from baseline (17.5 +/- 10.6%) to treatment with 14-mg (12.6 +/- 10.1%) and 21-mg (11.8 +/- 9.9%) nicotine patches. This reduction occurred despite an increase in treadmill exercise duration (p < 0.05) and higher serum nicotine levels (p < 0.001). There was a significant correlation between the reduction in defect size and exhaled carbon monoxide levels (p < 0.001) because patients reduced their smoking by approximately 74% during the trial. CONCLUSIONS: Nicotine patches, when used to promote smoking cessation, significantly reduce the extent of exercise-induced myocardial ischemia as assessed by exercise thallium-201 SPECT.


Assuntos
Doença das Coronárias/complicações , Isquemia Miocárdica/prevenção & controle , Nicotina/administração & dosagem , Abandono do Hábito de Fumar/métodos , Administração Cutânea , Doença das Coronárias/diagnóstico por imagem , Teste de Esforço , Feminino , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Isquemia Miocárdica/diagnóstico por imagem , Isquemia Miocárdica/etiologia , Projetos Piloto , Estudos Prospectivos , Fumar/efeitos adversos , Fumar/terapia , Tomografia Computadorizada de Emissão de Fóton Único
18.
Infect Immun ; 65(6): 2206-10, 1997 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9169752

RESUMO

Temperature-sensitive mutants of Actinobacillus pleuropneumoniae 4074, serotype 1, were isolated after treatment with nitrosoguanidine and enrichment with penicillin and D-cycloserine. Of the four temperature-sensitive mutants evaluated in mice, one (A-1) had a tight phenotype (i.e., it ceased replication immediately after transfer to the nonpermissive temperature [37 degrees C]) and three (1-2, 4-1, and 12-1) were coasters that continued replication for up to three generations after transfer to 37 degrees C. The reversion frequencies ranged from 10(-6) to 10(-9), and cutoff temperatures ranged from 33 to 35 degrees C. No major changes were detected in the biochemical profiles; agglutination reactions; electrophoretic profiles of the lipopolysaccharides, outer membrane proteins, and hemolysin proteins; hemolytic titers; or CAMP factor reactions of the mutants and the wild-type bacteria. Groups of 3- to 5-week-old, female ICR mice were immunized intranasally with three doses of 3.5 x 10(6) CFU of the mutants over 3 weeks and subsequently challenged intranasally with 5 50% lethal doses of the parental wild-type. Protection was induced by both the tight and the coaster mutants, with the 4-1 and 12-1 coasters eliciting greater protection (67 and 82%, respectively) than that induced by the A-1 tight mutant (57%). Intranasal immunization with both phenotypes induced serum antibody responses against the surface antigens and the hemolysin protein.


Assuntos
Actinobacillus pleuropneumoniae/imunologia , Vacinas Bacterianas/imunologia , Actinobacillus pleuropneumoniae/metabolismo , Animais , Ensaio de Imunoadsorção Enzimática , Feminino , Imunização , Camundongos , Camundongos Endogâmicos ICR , Mutação , Temperatura
20.
Curr Microbiol ; 34(3): 149-54, 1997 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9009067

RESUMO

The immunogenicity and protective potential of three temperature-sensitive mutants of Actinobacillus pleuropneumoniae were evaluated in mice with respect to antibodies against the capsular polysaccharide, lipopolysaccharide, outer membrane proteins, and hemolysin protein. Antibodies to the capsular polysaccharide and lipopolysaccharide could not be correlated with protection in the mice; there were no significant differences among the anti-capsular and anti-lipopolysaccharide antibody titers regardless of the severity of infection. Sera from mice immunized with the mutants and challenged with the wild type contained antibodies that reacted in immunoblots to four major outer membrane proteins(66, 39, 29, and 16 kDa) regardless of the severity of infection after challenge. Both the tight and coaster mutants synthesized and secreted the 105-kDa hemolysin protein exotoxin in vitro and in vivo; hemolysin protein neutralization titers and the blotting intensity of the sera, however, varied inversely with the severity of infection. Sera from mice surviving challenge with little to no lung involvement stained the hemolysin band more intensely and had significantly higher neutralization titers (P < 0.05) than sera from mice that either died or survived with severe pulmonary hemorrhage. These results confirm the importance of the hemolysin in pathogenesis and the need for including it in any vaccine preparation.


Assuntos
Actinobacillus pleuropneumoniae/imunologia , Anticorpos Antibacterianos/biossíntese , Proteínas Hemolisinas/imunologia , Animais , Proteínas da Membrana Bacteriana Externa/imunologia , Feminino , Imunização , Immunoblotting , Camundongos , Camundongos Endogâmicos ICR , Mutação , Temperatura
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