Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 27
Filter
1.
J Dent Educ ; 88(4): 468-471, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38279641

ABSTRACT

Providing disability-based accommodations is a multifaceted process that must balance the needs of dental students and their institutions. Reasonable accommodations must not compromise patient safety or cause an undue burden on the student or institution. Therefore, more creative approaches must be considered as the number of individuals and the types of learning disabilities have increased in recent years. In the clinical setting, providing accommodations also requires detailed advanced planning and collaboration to maintain program quality. However, current technical standards (TS) may serve as a barrier to entry into the health professions for people with disabilities. These individuals remain substantially underrepresented in dentistry despite bringing unique perspectives and experiences that can contribute to a diverse workforce of culturally proficient practitioners. In response, many schools have adopted a "functional" approach to TS that emphasizes a student's abilities rather than their limitations. In addition, innovative assistive technologies coupled with the application of critical pedagogy and universal design learning practices that engage people with the widest possible range of capabilities allows equitable approaches for learning and assessment while maintaining professional standards.


Subject(s)
Clinical Competence , Disabled Persons , Humans , Students , Schools, Medical , Education, Dental
2.
Transgend Health ; 8(4): 307-327, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37525832

ABSTRACT

Purpose: Providing inclusive and comprehensive gender-affirming care is critical to reducing health disparities (gaps in care) experienced by sexual and gender minorities (SGM). Currently, little is known about how medical students and residents are being trained to address the health needs of SGM persons or of the most effective methods. Methods: We conducted a systematic review of the research literature from 2000 to 2020 on the effectiveness of teaching medical students and residents on knowledge, attitudes, and skills in addressing the health of SGM persons and the strength of the research sample, design, and methods used. Results: We identified a total of 36 articles that assessed the impact of medical student and resident education on knowledge, comfort, attitudes, confidence, and skills in working with SGM patients. All studies utilized quasi-experimental designs, and found efficacious results. No study examined the impact of training on patient outcomes. Conclusion: Future studies will need to be powered and designed to assess the impact of training on patient outcomes.

3.
Ann Fam Med ; 21(Suppl 2): S92-S94, 2023 02.
Article in English | MEDLINE | ID: mdl-36849474

ABSTRACT

Transgender and gender-diverse (TGD) patients experience a greater burden of health disparities compared with their heterosexual/cisgender counterparts. Some of the poorer health outcomes observed in these populations are known to be associated with the prevalence of implicit bias, bullying, emotional distress, alcoholism, drug abuse, intimate partner violence, sexually transmitted infections (eg, human immunodeficiency virus and human papilloma virus), and cancer. The TGD populations face unique barriers to receiving both routine and gender-affirming health care (acquiring hormones and gender-affirming surgeries). Additional barriers to implementing affirming care training for TGD patients are lack of expertise among medical education faculty and preceptors both in undergraduate and in graduate medical education programs. Drawing on a systematic review of the literature, we propose a policy brief aimed at raising awareness about gender-affirming care among education planners and policy makers in government and advisory bodies.


Subject(s)
Education, Medical , Transgender Persons , Humans , Policy , Education, Medical, Graduate , Educational Status
5.
Med Sci Educ ; 31(2): 885-887, 2021 Apr.
Article in English | MEDLINE | ID: mdl-34457930

ABSTRACT

The idea of mid-level providers in dentistry grew from the increasing lack of access to oral care in rural and other underserved communities. To meet this need, dental therapists emerged. However, from an educational standpoint, the topic is hardly mentioned or discussed. This commentary discusses the role that dental therapists play in addressing oral health disparities and the reason more information about them should be included in dental and medical curricula. As the field of dentistry evolves and the lack of access to oral care persists, educating dental students and students in other healthcare professions about dental therapists should be an equally important task.

7.
Anat Sci Educ ; 11(5): 478-487, 2018 Sep.
Article in English | MEDLINE | ID: mdl-29251834

ABSTRACT

The complexity of the material being taught in clinical neuroscience within the medical school curriculum requires creative pedagogies to teach medical students effectively. Many clinical teaching strategies have been developed and are well described to address these challenges. However, only a few have been evaluated to determine their impact on the performance of students studying clinical neuroscience. Interactive, 2-hour, self-directed small-group interactive clinical case-based learning sessions were conducted weekly for 4 weeks to integrate concepts learned in the corresponding didactic lectures. Students in the small groups analyzed cases of patients suffering from neurological disease that were based on eight learning objectives that allowed them to evaluate neuroanatomical data and clinical findings before presenting their case analysis to the larger group. Students' performances on the formative quizzes and summative tests were compared to those of first-year medical students in the previous year for whom the self-directed, small-group interactive clinical sessions were not available. There was a significant improvement in the summative performance of first-year medical students with self-directed clinical case learning in the second year (Y2) of teaching clinical neuroscience (P < 0.05) when compared with first-year students in the first year (Y1) for whom the self-directed learning approach was not available. Student performance in the formative assessments between Y1 and Y2 was not significantly different (P = 0.803). A target of ≥70% student scoring above 80% in the final summative examination was met. The current study revealed evidence for the impact and educational outcomes of a self-directed, clinical teaching strategy in a clinical neuroscience curriculum for first-year medical students. Anat Sci Educ 11: 478-487. © 2017 American Association of Anatomists.


Subject(s)
Academic Performance/statistics & numerical data , Education, Medical, Undergraduate/methods , Neuroanatomy/education , Students, Medical/statistics & numerical data , Teaching , Adult , Brain/anatomy & histology , Brain/diagnostic imaging , Curriculum , Education, Medical, Undergraduate/statistics & numerical data , Female , Humans , Male , Program Evaluation , Schools, Medical/organization & administration , Schools, Medical/statistics & numerical data , Young Adult
8.
Nutr Cancer ; 64(7): 1112-21, 2012.
Article in English | MEDLINE | ID: mdl-23006051

ABSTRACT

Diallyl disulfide (DADS), a garlic organosulfur compound, has been researched as a cancer prevention agent; however, the role of DADS in the suppression of cancer initiation in nonneoplastic cells has not been elucidated. To evaluate DADS inhibition of early carcinogenic events, MCF-10A cells were pretreated (PreTx) with DADS followed by the ubiquitous carcinogen benzo(a)pyrene (BaP), or cotreated (CoTx) with DADS and BaP for up to 24 h. The cells were evaluated for changes in cell viability/proliferation, cell cycle, induction of peroxide formation, and DNA damage. BaP induced a statistically significant increase in cell proliferation at 6 h, which was attenuated with DADS CoTx. PreTx with 6 and 60 µM of DADS inhibited BaP-induced G2/M arrest by 68% and 78%, respectively. DADS, regardless of concentration or method, inhibited BaP-induced extracellular aqueous peroxide formation within 24 h. DADS attenuated BaP-induced DNA single-strand breaks at all time points through both DADS Pre- and CoTx, with significant inhibition for all treatments sustained after 6 h. DADS was effective in inhibiting BaP-induced cell proliferation, cell cycle transitions, reactive oxygen species, and DNA damage in a normal cell line, and thus may inhibit environmentally induced breast cancer initiation.


Subject(s)
Allyl Compounds/pharmacology , Benzo(a)pyrene/toxicity , Carcinogens/toxicity , Disulfides/pharmacology , Plant Extracts/pharmacology , Apoptosis/drug effects , Cell Cycle/drug effects , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Survival/drug effects , Chemoprevention , DNA Damage/drug effects , Garlic/chemistry , Humans , Reactive Oxygen Species/metabolism
9.
J Dent Educ ; 76(5): 523-33, 2012 May.
Article in English | MEDLINE | ID: mdl-22550097

ABSTRACT

It is well known that there is a large disparity between the proportions of African Americans, Hispanics, and American Indians in the general U.S. population and in the nation's dental profession. While these underrepresented minorities (URMs) together make up almost 30 percent of the population, they comprise only about 6 percent of U.S. dentists. For years, the American Dental Education Association has been diligently working with U.S. dental schools to reduce this disparity by increasing the diversity of their student bodies. However, with approximately 13 percent of first-year dental students coming from URM groups, the proportion of URM students entering dental school continues to remain significantly below that of the general population. Diversifying the dental profession is important for improving access to care for underrepresented groups, and student diversity provides better educational experiences for all students. Texas A&M Health Science Center Baylor College of Dentistry's strategy for increasing the number of URM dentists was to create a series of initiatives that together form a successful comprehensive program addressing students' awareness of and attraction to a dental career, academic enrichment, admissions, and graduation. The cumulative impact of this program is that the college enrolled greater numbers and proportions of URM students than any other non-minority U.S. dental school from 2006 to 2009. This article describes the program that led to these successes.


Subject(s)
Cultural Diversity , Minority Groups , Schools, Dental , Students, Dental , Black or African American/statistics & numerical data , Aptitude Tests , Career Choice , Education, Dental , Education, Predental , Educational Measurement , Hispanic or Latino/statistics & numerical data , Humans , Indians, North American/statistics & numerical data , Interpersonal Relations , Minority Groups/statistics & numerical data , Personnel Selection , Program Development , Program Evaluation , School Admission Criteria , Social Support , Students, Dental/statistics & numerical data , Texas , United States , Vulnerable Populations
10.
Food Chem Toxicol ; 50(7): 2524-30, 2012 Jul.
Article in English | MEDLINE | ID: mdl-22525868

ABSTRACT

Diallyl trisulfide (DATS) is a garlic organosulfide that is toxic to cancer cells, however, little is known about its effect in the initiation phase of carcinogenesis. We sought to determine whether DATS could inhibit the carcinogen, benzo(a)pyrene (BaP), from inducing precancerous activity, in vitro. MCF-10A cells were either pre-treated (PreTx) or concurrently treated (CoTx) with 1 µM BaP, and 6 or 60 µM DATS for up to 24h. The DATS 6 and 60 µM CoTx inhibited BaP-induced cell proliferation by an average of 71.1% and 120.8%, respectively, at 6h. The 60 µM DATS pretreatment decreased BaP-induced G2/M cell cycle transition by 127%, and reduced the increase in cells in the S-phase by 42%; whereas 60 µM DATS CoTx induced a 177% increase in cells in G1. DATS effectively inhibited (P<0.001) BaP-induced peroxide formation by at least 54%, which may have prevented the formation of BaP-induced DNA strand breaks. In this study, we reveal mechanisms involved in DATS inhibition of BaP-induced carcinogenesis, including inhibition of cell proliferation, regulation of cell cycle, attenuation of ROS formation, and inhibition of DNA damage. At the doses evaluated, DATS appears to be an effective attenuator of BaP-induced breast carcinogenesis, in vitro.


Subject(s)
Allyl Compounds/pharmacology , Benzo(a)pyrene/antagonists & inhibitors , Cell Transformation, Neoplastic , Sulfides/pharmacology , Benzo(a)pyrene/toxicity , Cell Line, Tumor , Comet Assay , DNA Damage , Flow Cytometry , Humans
11.
J Cell Biochem ; 112(11): 3364-72, 2011 Nov.
Article in English | MEDLINE | ID: mdl-21751240

ABSTRACT

Suppressor of cytokine signaling-3 (SOCS3) has multiple functions including inhibition of Janus kinase (Jak) activity, regulation of protein degradation, and suppression of cytokine signaling. SOCS3 modulates macrophage response to cytokines such as IL-6 and leptin that are systemically induced in obesity. Obesity is a suspected risk factor for SOCS3-related pathology such as rheumatoid arthritis and Crohn's disease as well as zoledronic acid (ZA)-induced osteonecrosis of the jaw (ONJ). Thus, understanding the ability of bisphosphonates to modulate SOCS3 is necessary to qualify their contribution to these disorders. ONJ occurs in up to 10% of patients using intravenous bisphosphonates and has an unknown pathogenesis that may be linked to decreased bone turnover, altered vascularity, bacterial invasion, and compromised wound healing. Given the increased risk of ONJ with obesity and importance of macrophages in wound healing, we hypothesized that amino-bisphosphonates could contribute to the pathogenesis of ONJ by regulating macrophage responses to cytokines such as leptin and IL-6. We report that ZA is a novel inhibitor of SOCS3 in primary macrophages and human ONJ biopsy specimens. Inhibition of SOCS3 by ZA resulted in significant increases in IL-6 production. SOCS3 transcription is regulated by nuclear accumulation of phosphorylated-Stat3 (P-Stat3). We found that ZA decreased phosphorylation of Stat3 in a mevalonate-pathway dependent manner. However, restoration of P-Stat3 was not sufficient to correct SOCS3 inhibition. We propose that disruption of macrophage SOCS3 expression by amino-bisphosphonates such as ZA may be a novel contributor to inflammatory phenotypes in obesity and the pathogenesis of ONJ.


Subject(s)
Cytokines/biosynthesis , Diphosphonates/pharmacology , Imidazoles/pharmacology , Macrophages/drug effects , Suppressor of Cytokine Signaling Proteins/antagonists & inhibitors , Animals , Base Sequence , Blotting, Western , Cell Line , DNA Primers , Enzyme-Linked Immunosorbent Assay , Humans , Interleukin-6/biosynthesis , Leptin/physiology , Macrophages/metabolism , Mevalonic Acid/metabolism , Mice , Polymerase Chain Reaction , Signal Transduction , Suppressor of Cytokine Signaling 3 Protein , Suppressor of Cytokine Signaling Proteins/metabolism , Zoledronic Acid
12.
Article in English | MEDLINE | ID: mdl-21237434

ABSTRACT

OBJECTIVE: This study tested the effects of bisphosphonates (BPs) on the suppressor of cytokine signaling 3 (SOCS3) protein in macrophages. SOCS3 has been shown to regulate cell differentiation and survival; however, its potential role in mediating the effects of BPs has not been explored. STUDY DESIGN: The cell viability of murine RAW 267.4 macrophages was assessed after culturing with control medium or media containing increasing concentrations of 2 BPs (ibandronate or clodronate) for 24, 48, and 72 hours. The phosphorylation status of signal transducer and activator of transcription 3 (STAT3) and the expression of SOCS3 protein levels were determined by Western blot analysis. RESULTS: In control cultures, STAT3 phosphorylation and STAT3 and SOCS3 protein levels increased within 5 minutes after the addition of fresh medium. This increase was inhibited in cultures treated with both BPs. Macrophage cell viability also decreased after BP treatment. CONCLUSIONS: These data demonstrate that, in addition to their effects on macrophage viability, BPs can decrease STAT3 and SOCS3 expression, which are important modulators of immune responses and bone homeostasis.


Subject(s)
Bone Density Conservation Agents/pharmacology , Diphosphonates/pharmacology , Macrophages/drug effects , STAT3 Transcription Factor/drug effects , Suppressor of Cytokine Signaling Proteins/drug effects , Animals , Cell Differentiation/drug effects , Cell Survival/drug effects , Cells, Cultured , Clodronic Acid/pharmacology , Dose-Response Relationship, Drug , Ibandronic Acid , Immunity, Innate/drug effects , Macrophages/metabolism , Mice , Osteoclasts/cytology , Osteoclasts/drug effects , STAT3 Transcription Factor/metabolism , Suppressor of Cytokine Signaling 3 Protein , Suppressor of Cytokine Signaling Proteins/metabolism
13.
J Am Coll Dent ; 78(4): 40-7, 2011.
Article in English | MEDLINE | ID: mdl-22416618

ABSTRACT

There is a large disparity between the proportions of African-Americans, Hispanics, and Native Americans in the general population and in the dental profession. While these underrepresented minorities (URMs) as a group make up almost 30% of the United States population, they constitute only about 6% of the nation's dentists. Eliminating this disparity is important in addressing access to care for underrepresented groups. Texas A&M Health Science Center Baylor College of Dentistry (TAMHSC-BCD) enrolled greater numbers and proportions of URM students than any other non-minority school from 2006-2010. Strategies used to achieve this level of diversity include a Whole File Review process; career awareness activities for elementary, junior high and high school students; and academic enrichment programs for college students and college graduates. Retaining and graduating URM students is just as important as enrolling them. TAMHSC-BCD's retention rate over the last five years is 95.7% for all students and 92.5% for URM students. A wide range of services aids in the retention process. These services are available to all students and include monitoring of students' academic performance followed up with academic advisement as appropriate, peer tutoring, an alternative five-year curriculum, professional psychological counseling, professional learning assessments, social support; and mentoring through student organizations. The retention program at TAMHSC-BCD can serve as a model for other dental and other health professions schools seeking ways to ensure the academic success of their URM students. The more of these students we enroll and graduate, the more the problem of access to dental care is addressed.


Subject(s)
Minority Groups/statistics & numerical data , Personnel Selection/statistics & numerical data , Schools, Dental , Students, Dental/statistics & numerical data , Black or African American/statistics & numerical data , Career Choice , Counseling , Cultural Diversity , Curriculum , Education, Dental , Educational Measurement , Health Services Accessibility , Hispanic or Latino/statistics & numerical data , Humans , Indians, North American/statistics & numerical data , Interpersonal Relations , Mentors , Program Development , Program Evaluation , School Admission Criteria , Social Support , Texas
14.
Exp Biol Med (Maywood) ; 234(4): 361-71, 2009 Apr.
Article in English | MEDLINE | ID: mdl-19176873

ABSTRACT

Acute lung injury (ALI) has been documented clinically following several pathological states such as trauma, septic shock and pneumonia. The histopathological characteristics, paired with the production of a number of cellular pro-inflammatory mediators, play a crucial role in the progression of ALI. During ALI, polymorphonuclear neutrophil (PMN)-mediated apoptosis is delayed by macrophages, possibly via effects on the Fas/FasL mediated pathway, leading to the accumulation of these cells at the site of injury and inflammation. The transcriptional regulation of NFkappaB, CREB, and AP-1 also regulates the pathogenesis of ALI. During sepsis and septic shock, we found evidence of infiltrating leukocytes in the alveolar spaces along with an increased number of TUNEL-positive cells in the lung sections. We also observed an increased expression of TRADD and Bax/Bcl(2) ratio at 7 days post-sepsis. In contrast, the NFkappaB/IkappaB ratio increased at 1 day post-sepsis. Together, these data provide evidence illustrating the induction of apoptosis in lung tissues subsequent to the onset of polymicrobial sepsis. The results support the concept that the upregulation of apoptosis following lung inflammation plays a crucial role in the development of acute lung injury and related disorders such as ARDS.


Subject(s)
Acute Lung Injury/pathology , Apoptosis/physiology , Signal Transduction , Acute Lung Injury/complications , Acute Lung Injury/metabolism , Cytokines/physiology , Humans , Macrophages, Alveolar/physiology , Neutrophils/physiology , Sepsis/complications , Sepsis/metabolism , Sepsis/pathology , Transcription Factors/metabolism , Transcription Factors/physiology
15.
Eur J Immunol ; 39(2): 561-70, 2009 Feb.
Article in English | MEDLINE | ID: mdl-19180470

ABSTRACT

IgG complexes bind to Fc receptor family members FcgammaRI (CD64), FcgammaRII (CD32) and FcgammaRIII (CD16), activating cell MAPK and PI3K resulting in increased cytokine production from particular leukocytes. The signaling molecules involved in cytokine production after cross-linking CD16 have not been determined in monocytes. To address this question, TNF-alpha, IL-1beta and IL-6 were measured in activated monocytes after inhibiting MEK1/2, PI3K and glycogen synthase kinase-beta (GSK-3beta). The roles of GSK-3beta and NF-kappaB were then determined using reporter assays and siRNA treatment. The data suggested that an MAPK pathway stimulated TNF-alpha release but that active PI3K limited TNF-alpha, IL-1beta and IL-6 cytokine production after cross-linking CD16. PI3K was also shown to limit nuclear translocation of NF-kappaB. The limiting effect of PI3K on TNF-alpha production from activated monocytes depended on the decrease of GSK-3beta activity, which significantly reduced the transactivation of NF-kappaB. Moreover, the TNF-alpha production induced by CD16 cross-linking was reduced in monocytes after treatment with siRNA against NF-kappaB, implying that this transcription factor functioned in TNF-alpha production. The results suggest that CD16 cross-linking activated PI3K and that active PI3K limited TNF-alpha production by inhibiting GSK-3beta activity, that blocked the action of NF-kappaB.


Subject(s)
Glycogen Synthase Kinase 3/metabolism , Monocytes/immunology , Phosphatidylinositol 3-Kinases/metabolism , Receptors, IgG/immunology , Tumor Necrosis Factor-alpha/metabolism , Cells, Cultured , GPI-Linked Proteins , Glycogen Synthase Kinase 3 beta , Humans , Interleukin-1beta/immunology , Interleukin-1beta/metabolism , Interleukin-6/immunology , Interleukin-6/metabolism , Mitogen-Activated Protein Kinase Kinases/metabolism , Monocytes/metabolism , NF-kappa B/metabolism , Receptors, IgG/metabolism , Signal Transduction/immunology
16.
Cir Cir ; 76(4): 291-8, 2008.
Article in Spanish | MEDLINE | ID: mdl-18778538

ABSTRACT

BACKGROUND: Hemorrhagic shock (HS) results in oxidative stress to cells and in the induction of the inflammatory response, with an increased expression of a number of proinflammatory mediators and cytokines. We tested the ability of the nitric oxide (NO) donor sodium nitroprusside (NP) to reduce tissue injury in a rodent model of uncontrolled hemorrhagic shock. METHODS: Seventy two Sprague Dawley rats weighing 250-300 g were subjected to a model of uncontrolled hemorrhagic shock. Four groups of animals were included (n = 18 per group): sham/saline, sham/NP, shock/saline, shock/NP. Experimental design consisted of the development of hemorrhagic shock (3 ml/100 g) in a 15-min period, tail amputation (75%) and drug administration at 30 min, fluid resuscitation (FR) with Ringer's lactate (RL) solution to reach a mean arterial pressure (MAP) of 40 mmHg, a hospital phase of 60 min with hemostasis and FR with LR solution to reach a MAP of 70 mmHg, and a 3-day observation phase. Treatment at the beginning of resuscitation included either normal saline (groups 1, 3) or NP (0.5 mg/kg) (groups 2, 4). The following parameters were evaluated: fluid requirements for resuscitation, liver injury tests, liver tissue myeloperoxidase (MPO), liver histology, and 3-day survival. RESULTS: NP significantly reduced fluid requirements for resuscitation (p = 0.0001). We also observed an improved statistically significant difference in tests demonstrating hepatic injury (p = 0.0001), neutrophil infiltration as evidences by liver MPO (p <0.05), and histology studies (p = 0.001). Survival was also increased from 40% in controls to 60% with NP treatment. CONCLUSIONS: These data suggest that excess NO mediates hemorrhage-induced liver injury, and that the suppression of NO with NP may reduce the pathological consequences of severe hemorrhage, possibly by scavenging superoxide (O(2)(-)), thus limiting the production of more aggressive radicals.


Subject(s)
Hepatitis/prevention & control , Liver Circulation/drug effects , Nitric Oxide Donors/therapeutic use , Nitroprusside/therapeutic use , Reperfusion Injury/prevention & control , Shock, Hemorrhagic/drug therapy , Animals , Drug Evaluation, Preclinical , Fluid Therapy , Hepatitis/etiology , Hepatitis/physiopathology , Isotonic Solutions/administration & dosage , Isotonic Solutions/therapeutic use , Liver/blood supply , Liver/pathology , Male , Models, Biological , Necrosis , Nitric Oxide/physiology , Nitric Oxide Donors/pharmacology , Nitroprusside/pharmacology , Oxidative Stress/drug effects , Peroxidase/analysis , Rats , Rats, Sprague-Dawley , Reactive Oxygen Species/metabolism , Reperfusion Injury/etiology , Reperfusion Injury/physiopathology , Resuscitation , Ringer's Lactate , Shock, Hemorrhagic/complications , Shock, Hemorrhagic/physiopathology , Single-Blind Method
17.
Cir. & cir ; 76(4): 291-298, jul.-ago. 2008. graf, ilus
Article in Spanish | LILACS | ID: lil-568084

ABSTRACT

BACKGROUND: Hemorrhagic shock (HS) results in oxidative stress to cells and in the induction of the inflammatory response, with an increased expression of a number of proinflammatory mediators and cytokines. We tested the ability of the nitric oxide (NO) donor sodium nitroprusside (NP) to reduce tissue injury in a rodent model of uncontrolled hemorrhagic shock. METHODS: Seventy two Sprague Dawley rats weighing 250-300 g were subjected to a model of uncontrolled hemorrhagic shock. Four groups of animals were included (n = 18 per group): sham/saline, sham/NP, shock/saline, shock/NP. Experimental design consisted of the development of hemorrhagic shock (3 ml/100 g) in a 15-min period, tail amputation (75%) and drug administration at 30 min, fluid resuscitation (FR) with Ringer's lactate (RL) solution to reach a mean arterial pressure (MAP) of 40 mmHg, a hospital phase of 60 min with hemostasis and FR with LR solution to reach a MAP of 70 mmHg, and a 3-day observation phase. Treatment at the beginning of resuscitation included either normal saline (groups 1, 3) or NP (0.5 mg/kg) (groups 2, 4). The following parameters were evaluated: fluid requirements for resuscitation, liver injury tests, liver tissue myeloperoxidase (MPO), liver histology, and 3-day survival. RESULTS: NP significantly reduced fluid requirements for resuscitation (p = 0.0001). We also observed an improved statistically significant difference in tests demonstrating hepatic injury (p = 0.0001), neutrophil infiltration as evidences by liver MPO (p <0.05), and histology studies (p = 0.001). Survival was also increased from 40% in controls to 60% with NP treatment. CONCLUSIONS: These data suggest that excess NO mediates hemorrhage-induced liver injury, and that the suppression of NO with NP may reduce the pathological consequences of severe hemorrhage, possibly by scavenging superoxide (O(2)(-)), thus limiting the production of more aggressive radicals.


Subject(s)
Animals , Male , Rats , Shock, Hemorrhagic/drug therapy , Liver Circulation/drug effects , Nitric Oxide Donors/therapeutic use , Hepatitis/prevention & control , Nitroprusside/therapeutic use , Reperfusion Injury/prevention & control , Drug Evaluation, Preclinical , Nitric Oxide Donors/pharmacology , Reactive Oxygen Species/metabolism , Oxidative Stress/drug effects , Fluid Therapy , Hepatitis , Isotonic Solutions , Liver , Models, Biological , Necrosis , Nitroprusside/pharmacology , Nitric Oxide/physiology , Peroxidase/analysis , Rats, Sprague-Dawley , Reperfusion Injury , Resuscitation , Shock, Hemorrhagic , Single-Blind Method
18.
Antioxid Redox Signal ; 10(5): 973-81, 2008 May.
Article in English | MEDLINE | ID: mdl-18257742

ABSTRACT

We recently showed that acute oxidant-related lung injury (ALI) in rats after application of 2-chloroethyl ethyl sulfide (CEES) is attenuated by the airway instillation of antioxidants. We investigated whether intratracheal administration of antioxidant-containing liposomes immediately after instillation of CEES would attenuate short-term as well as long-term (fibrotic) effects of CEES-induced lung injury. In the acute injury model (4 h after injury), N-acetylcysteine (NAC)-containing liposomes were protective and reduced to baseline levels both the lung permeability index and the appearance of proinflammatory mediators in bronchoalveolar lavage fluids from CEES-exposed lungs. Similar results were obtained when rat alveolar macrophages were incubated in vitro with either CEES or lipopolysaccharide in the presence of NAC-liposomes. When lung fibrosis 3 weeks after CEES was quantitated by using hydroxyproline content, liposomes containing NAC or NAC + glutathione had no effects, but liposomes containing alpha/gamma-tocopherol alone or with NAC significantly suppressed the increase in lung hydroxyproline. The data demonstrate that delivery of antioxidants via liposomes to CEES-injured lungs is, depending on liposomal content, protective against ALI, prevents the appearance of proinflammatory mediators in bronchoalveolar fluids, and suppresses progressive fibrosis. Accordingly, the liposomal strategy may be therapeutically useful in CEES-induced lung injury in humans.


Subject(s)
Antioxidants , Liposomes , Respiratory Distress Syndrome/drug therapy , Respiratory Distress Syndrome/prevention & control , Acetylcysteine/administration & dosage , Acetylcysteine/metabolism , Acetylcysteine/therapeutic use , Animals , Antioxidants/chemistry , Antioxidants/metabolism , Antioxidants/therapeutic use , Bronchoalveolar Lavage Fluid/chemistry , Chemokines/metabolism , Cytokines/metabolism , Free Radical Scavengers/administration & dosage , Free Radical Scavengers/metabolism , Free Radical Scavengers/therapeutic use , Humans , Liposomes/administration & dosage , Liposomes/chemistry , Liposomes/metabolism , Liposomes/therapeutic use , Lung/cytology , Lung/drug effects , Lung/metabolism , Lung/pathology , Macrophages, Alveolar/metabolism , Male , Mustard Gas/analogs & derivatives , Mustard Gas/pharmacology , Rats , Rats, Long-Evans , Respiratory Distress Syndrome/chemically induced , Respiratory Distress Syndrome/pathology , Tocopherols/administration & dosage , Tocopherols/metabolism , Tocopherols/therapeutic use
19.
J Immunol ; 177(2): 1306-13, 2006 Jul 15.
Article in English | MEDLINE | ID: mdl-16818791

ABSTRACT

Neutrophil accumulation in the lung plays a pivotal role in the pathogenesis of acute lung injury during sepsis. Directed movement of neutrophils is mediated by a group of chemoattractants, especially CXC chemokines. Local lung production of CXC chemokines is intensified during experimental sepsis induced by cecal ligation and puncture (CLP), as reflected by rising levels of MIP-2 and cytokine-induced neutrophil chemoattractant-1 in bronchoalveolar lavage fluids. Alveolar macrophages are primed and blood neutrophils are down-regulated for production of MIP-2 and cytokine-induced neutrophil chemoattractant production in response to LPS and C5a. Under these conditions of stimulation, activation of MAPKs (p38, p42/p44) occurs in sham neutrophils but not in CLP neutrophils, while under the same conditions phosphorylation of p38 and p42/p44 occurs in both sham and CLP alveolar macrophages. These data indicate that, under septic conditions, there is impaired signaling in neutrophils and enhanced signaling in alveolar macrophages, resulting in CXC chemokine production, and C5a appears to play a pivotal role in this process. As a result, CXC chemokines increase in lung, setting the stage for neutrophil accumulation in lung during sepsis.


Subject(s)
Macrophages, Alveolar/immunology , Macrophages, Alveolar/metabolism , Neutrophils/immunology , Neutrophils/metabolism , Sepsis/immunology , Sepsis/metabolism , Signal Transduction/immunology , Amino Acid Sequence , Animals , Bronchoalveolar Lavage Fluid/immunology , Cecum , Cell Movement/immunology , Chemokine CXCL2 , Chemokines, CXC/biosynthesis , Chemokines, CXC/blood , Chemokines, CXC/metabolism , Complement C5a/antagonists & inhibitors , Complement C5a/pharmacology , Ligation , Lipopolysaccharides/pharmacology , Macrophages, Alveolar/pathology , Male , Molecular Sequence Data , Neutrophils/pathology , Punctures , Rats , Rats, Long-Evans , Receptor, Anaphylatoxin C5a/biosynthesis , Receptor, Anaphylatoxin C5a/genetics , Receptor, Anaphylatoxin C5a/physiology , Sepsis/pathology
20.
J Immunol ; 172(12): 7703-12, 2004 Jun 15.
Article in English | MEDLINE | ID: mdl-15187153

ABSTRACT

Stat3 plays diverse roles in biological processes including cell proliferation, survival, apoptosis, and inflammation. Very little is known regarding its activation and function in the lung during acute inflammation. We now show that Stat3 activation was triggered in lungs and in alveolar macrophages after intrapulmonary deposition of IgG immune complexes in rats. Low levels of constitutive Stat3 were observed in normal rat lungs as determined by the EMSA. Stat3 activity in whole lung extracts increased 2 h after initiation of IgG immune complex deposition, reaching maximal levels by 4 h, whereas Stat3 activation was found in alveolar macrophages as early as 30 min after onset of injury. Expression and activation of Stat3 mRNA, protein, and protein phosphorylation was accompanied by increased gene expression of IL-6, IL-10, and suppressor of cytokine signaling-3 in whole lung tissues. Both Tyr(705) and Ser(727) phosphorylation were involved in Stat3 activation as assessed in whole lung extracts. C5a (complement 5, fragment a) per se can induce phosphorylation of Ser(727) of Stat3. In vivo, Stat3 activation was dramatically suppressed by depletion of neutrophils or lung macrophages, resulting in reduced gene expression of IL-6 and IL-10 in whole lung tissues. Using blocking Abs to IL-6, IL-10, and C5a, Stat3 activation induced by IgG immune complexes was markedly diminished. These data suggest in the lung injury model used that activation of Stat3 in lungs is macrophage dependent and neutrophil dependent. IL-6, IL-10, and C5a contribute to Stat3 activation in inflamed rat lung.


Subject(s)
DNA-Binding Proteins/metabolism , Respiratory Distress Syndrome/metabolism , Trans-Activators/metabolism , Animals , Antigen-Antibody Complex/metabolism , Complement C5a/physiology , Cytokines/biosynthesis , Cytokines/physiology , DNA-Binding Proteins/analysis , DNA-Binding Proteins/genetics , Immunoglobulin G/metabolism , Lung/cytology , Macrophages, Alveolar/chemistry , Macrophages, Alveolar/physiology , Male , Neutrophils/chemistry , Neutrophils/physiology , Phosphorylation , RNA, Messenger/analysis , Rats , Rats, Long-Evans , Respiratory Distress Syndrome/immunology , STAT3 Transcription Factor , Time Factors , Trans-Activators/analysis , Trans-Activators/genetics
SELECTION OF CITATIONS
SEARCH DETAIL
...