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Aranda Z, Caamal V, Montaño M, Bernal D, Meneses S. Exploring how non-clinical factors in childbirth care shape users' experiences in public health facilities in rural Chiapas, Mexico: a qualitative study using the WHO health systems responsiveness framework. BMC Pregnancy Childbirth 2024; 24:173. [PMID: 38424565 PMCID: PMC10905866 DOI: 10.1186/s12884-024-06357-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Accepted: 02/19/2024] [Indexed: 03/02/2024] Open
Abstract
INTRODUCTION Many Mexicans face barriers to receive delivery care from qualified professionals, especially indigenous and poor sectors of the population, which represent most of the population in the state of Chiapas. When access to institutional delivery care is an option, experiences with childbirth care are often poor. This underscores the need for evidence to improve the quality of services from the user's perspective. The present study was conceived with the objective of understanding how non-clinical aspects of care shape women's birthing experiences in public health institutions in Chiapas. METHODS We conducted an exploratory qualitative study. Data collection consisted in 20 semi-structured interviews to women who had delivered in a public health facility in Chiapas during the last six months prior to the interview. For the design of the interview guide we used the WHO health system responsiveness framework, which focus on the performance of the health system in terms of the extent to which it delivers services according to the "universally legitimate expectations of individuals" and focuses on the non-financial and non-clinical qualities of care. The resulting data were analyzed using thematic analysis methodology. RESULTS We identified a total of 16 themes from the data, framed in eight categories which followed the eight domains of the WHO health systems responsiveness framework: Choice of the provider and the facility, prompt attention, quality of basic amenities, access to social support, respectful treatment, privacy, involvement in decisions, and communication. We shed light on the barriers women face in receiving prompt care, aspects of health facilities that impact women's comfort, the relevance of being provided with adequate food and drink during institutional delivery, how accompaniment contributes positively to the birthing experience, the aspects of childbirth that women find important to decide on, and how providers' interpersonal behaviors affect the birthing experience. CONCLUSIONS We have identified non-clinical aspects of childbirth care that are important to the user experience and that are not being satisfactorily addressed by public health institutions in Chiapas. This evidence constitutes a necessary first step towards the design of strategies to improve the responsiveness of the Chiapas health system in childbirth care.
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Affiliation(s)
- Zeus Aranda
- Partners In Health Mexico (Compañeros En Salud), Ángel Albino Corzo, Calle Primera Pte. Sur 25, Colonia Centro, 30370 Ángel Albino Corzo, Chiapas, México.
| | - Viviana Caamal
- Partners In Health Mexico (Compañeros En Salud), Ángel Albino Corzo, Calle Primera Pte. Sur 25, Colonia Centro, 30370 Ángel Albino Corzo, Chiapas, México
| | - Mariana Montaño
- Partners In Health Mexico (Compañeros En Salud), Ángel Albino Corzo, Calle Primera Pte. Sur 25, Colonia Centro, 30370 Ángel Albino Corzo, Chiapas, México
| | - Daniel Bernal
- Escuela de Gobierno y Transformación Pública, Instituto Tecnológico y de Estudios Superiores de Monterrey, Ciudad de México, México
| | - Sergio Meneses
- Center for Health Systems Research, National Institute of Public Health, Cuernavaca, Morelos, México
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Montaño M, Macías V, Molina RL, Aristizabal P, Nigenda G. The experience of obstetric nursing students in an innovative maternal care programme in Chiapas, Mexico: a qualitative study. Sex Reprod Health Matters 2022; 30:2095708. [PMID: 35904539 PMCID: PMC9341332 DOI: 10.1080/26410397.2022.2095708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
In Mexico, over the last decade, more non-physician medical professionals have been participating in birth care according to recent federal regulations. So far, very few sites have been able to implement birth care models where midwives and obstetric nurses participate. We describe the experience of a group of intern obstetric nurses participating in a model that provides respectful birth care to rural populations, managed by an international NGO in partnership with the Ministry of Health of Chiapas, Mexico. We conducted a case study including individual interviews and focus group discussions with obstetric nurse interns participating in the Compañeros En Salud programme over four years from 2016 to 2019. We applied targeted content analysis to the qualitative data. There were 28 participants from 4 groups of interns. Informants expressed their opinions in four areas: (a) training as a LEO, (b) training experience at CES, (c) LEO role in health care delivery; and (d) LEOs' perspectives about respectful maternity care. Interns identified gaps in their training including a higher load of theoretical content vs practical experience, as well as little supervision of clinical care in public hospitals. Their adaptation to the health services model has increased over time, and recent classes acknowledge the difficulties that earlier ones had to confront, including the challenging interactions with hospital staff. Interns have incorporated the value of respectful birth care and their role to protect this right in rural populations. Findings could be useful to call for the expansion of the model in public birth centres.
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Affiliation(s)
- M Montaño
- Maternal Health Coordinator, Partners in Health, Jaltenango, Mexico
| | - V Macías
- General Director, Partners in Health, Jaltenango, Mexico
| | - RL Molina
- Assistant Professor, Department of Obstetrics and Gynecology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - P Aristizabal
- Associate Professor, Iztacala Faculty of Higher Studies, National Autonomous University of Mexico, Mexico City, Mexico
| | - G Nigenda
- Professor, National School of Nursing and Obstetrics, National Autonomous University of Mexico, Mexico City, Mexico
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Buckner M, Montaño M, Vanegas I. Integrating Traditional Midwives into the State Health System: A Critical Case Study from Chiapas, Mexico. Med Anthropol 2022; 41:824-838. [PMID: 36069564 DOI: 10.1080/01459740.2022.2113395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Efforts to integrate traditional midwives into state health systems have not succeeded in reducing perinatal mortality, but have nevertheless continued in many countries, including Mexico. The authors used ethnographic methods to examine an NGO's efforts to integrate traditional midwives into the state health system in the Sierra Madre region of Chiapas, Mexico. We found that most of the traditional midwives in the study area have little to gain by such integration, and ask whether it is possible, practical, and ethical to integrate traditional midwives into health institutions until and unless such policy is grounded in local realities.
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Affiliation(s)
- Margaret Buckner
- Department of Sociology and Anthropology, Missouri State University, Springfield, MO, USA
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Aranda Z, Binde T, Tashman K, Tadikonda A, Mawindo B, Maweu D, Boley EJ, Mphande I, Dumbuya I, Montaño M, Clisbee M, Mvula MG, Ndayizigiye M, Casella Jean-Baptiste M, Varney PF, Anyango S, Grépin KA, Law MR, Mugunga JC, Hedt-Gauthier B, Fulcher IR. Disruptions in maternal health service use during the COVID-19 pandemic in 2020: experiences from 37 health facilities in low-income and middle-income countries. BMJ Glob Health 2022; 7:bmjgh-2021-007247. [PMID: 35012970 PMCID: PMC8753094 DOI: 10.1136/bmjgh-2021-007247] [Citation(s) in RCA: 57] [Impact Index Per Article: 28.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 12/10/2021] [Indexed: 01/01/2023] Open
Abstract
The COVID-19 pandemic has heterogeneously affected use of basic health services worldwide, with disruptions in some countries beginning in the early stages of the emergency in March 2020. These disruptions have occurred on both the supply and demand sides of healthcare, and have often been related to resource shortages to provide care and lower patient turnout associated with mobility restrictions and fear of contracting COVID-19 at facilities. In this paper, we assess the impact of the COVID-19 pandemic on the use of maternal health services using a time series modelling approach developed to monitor health service use during the pandemic using routinely collected health information systems data. We focus on data from 37 non-governmental organisation-supported health facilities in Haiti, Lesotho, Liberia, Malawi, Mexico and Sierra Leone. Overall, our analyses indicate significant declines in first antenatal care visits in Haiti (18% drop) and Sierra Leone (32% drop) and facility-based deliveries in all countries except Malawi from March to December 2020. Different strategies were adopted to maintain continuity of maternal health services, including communication campaigns, continuity of community health worker services, human resource capacity building to ensure compliance with international and national guidelines for front-line health workers, adapting spaces for safe distancing and ensuring the availability of personal protective equipment. We employ a local lens, providing prepandemic context and reporting results and strategies by country, to highlight the importance of developing context-specific interventions to design effective mitigation strategies.
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Affiliation(s)
- Zeus Aranda
- Compañeros En Salud/Partners In Health-Mexico, Ángel Albino Corzo, Mexico
| | - Thierry Binde
- Partners In Health-Sierra Leone, Koidu, Sierra Leone
| | - Katherine Tashman
- Global Health and Social Medicine, Harvard Medical School, Boston, Massachusetts, USA.,Harvard Data Science Initiative, Boston, Massachusetts, USA
| | - Ananya Tadikonda
- Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Bill Mawindo
- Partners In Health-Sierra Leone, Koidu, Sierra Leone
| | | | | | - Isaac Mphande
- Abwenzi Pa Za Umoyo/Partners In Health-Malawi, Neno, Malawi
| | - Isata Dumbuya
- Partners In Health-Sierra Leone, Koidu, Sierra Leone
| | - Mariana Montaño
- Compañeros En Salud/Partners In Health-Mexico, Ángel Albino Corzo, Mexico
| | - Mary Clisbee
- Zanmi Lasante/Partners In Health-Haiti, Croix-des-Bouquets, Haiti
| | | | | | | | | | | | - Karen Ann Grépin
- School of Public Health, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong, Hong Kong
| | - Michael R Law
- Centre for Health Services and Policy Research, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Jean Claude Mugunga
- Global Health and Social Medicine, Harvard Medical School, Boston, Massachusetts, USA.,Partners In Health, Boston, Massachusetts, USA
| | - Bethany Hedt-Gauthier
- Harvard Medical School, Boston, Massachusetts, USA.,Biostatistics, Harvard University T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Isabel R Fulcher
- Global Health and Social Medicine, Harvard Medical School, Boston, Massachusetts, USA.,Harvard Data Science Initiative, Boston, Massachusetts, USA
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Carrasco H, Napier H, Giber D, Kang S, Aguerreberre M, Hing M, Silva VSTM, Montaño M, Perry H, Palazuelos D. Accompanimeter 1.0: creation and initial field testing of a tool to assess the extent to which the principles and building blocks of accompaniment are present in community health worker programs. Glob Health Action 2020; 12:1699348. [PMID: 31829114 PMCID: PMC6913655 DOI: 10.1080/16549716.2019.1699348] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Background: The strategic incorporation of community health workers (CHWs) into health system strengthening efforts is recognized as a critical and high-value approach for meeting the Sustainable Development Goals established by the United Nations in 2015. How to best build CHW programs, however, is prone to a wide variety of opinions and philosophies, many of which are often externally imposed. Partners in Health (PIH) is a non-governmental organization that pioneered an approach to healthcare system strengthening, called accompaniment, in which CHWs play a key role. Learning from PIH is a critical first step in replicating the organization’s achievements beyond PIH. As such, PIH has developed a tool, referred to as the ‘Accompanimeter 1.0,’ that serves to evaluate existing CHW programs and guide adjustments in programming. Objective: To provide a standardized approach for defining, assessing, and implementing accompaniment in CHW programs using a tool called the Accompanimeter 1.0. Methods: Development of this tool included three stages: (1) desk review of literature relevant to the work of CHWs globally, (2) discussions among colleagues and initial field testing, (3) feedback from colleagues who are experts in community health and in the principles of accompaniment. Results: Three core principles of accompaniment in a CHW program were identified: professionalization, CHWs as bridges to institutional strength, and community proximity. These core principles direct five thematic areas that are found in successful CHW programs: Partnering (co-creating engagement with a continuous and intersectoral dialogue to improve the program); Choosing (identifying the right people for the right job); Educating (building CHWs´ capacity); Incentivizing (enabling CHWs to perform their work without financial sacrifice); Supervising (mentoring CHWs for personal growth). Conclusions: The Accompanimeter 1.0 can serve as a helpful tool for CHW program implementation and policy decisions that maximize system-side inputs, community engagement, and support for individuals with medical issues.
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Affiliation(s)
- Hector Carrasco
- Doctor of Public Health Program, Harvard T.H. Chan School of Public Health, Boston, MA, USA.,Ciencias Básicas, Escuela de Medicina y Ciencias de la Salud del Tecnológico de Monterrey, México City, México
| | - Harriet Napier
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - David Giber
- Community Health Systems, Partners In Health, Boston, MA, USA
| | - Stephanie Kang
- Doctor of Public Health Program, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Mercedes Aguerreberre
- Department of Global Health and Social Medicine, Harvard Medical School, Boston, MA, USA.,Department of Maternal Health, Partners In Health (Compañeros En Salud), Ángel Albino Corzo, Chis, México
| | - Matthew Hing
- David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | | | - Mariana Montaño
- Department of Maternal Health, Partners In Health (Compañeros En Salud), Ángel Albino Corzo, Chis, México
| | - Henry Perry
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Daniel Palazuelos
- Community Health Systems, Partners In Health, Boston, MA, USA.,Department of Global Health and Social Medicine, Harvard Medical School, Boston, MA, USA
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Molina RL, Villar J, Reyes A, Elliott J, Begley M, Johnson M, Palazuelos L, Montaño M, Flores H, Semrau KEA, Palazuelos D. Delivery practices and care experience during implementation of an adapted safe childbirth checklist and respectful care program in Chiapas, Mexico. Int J Gynaecol Obstet 2019; 145:101-109. [PMID: 30702140 DOI: 10.1002/ijgo.12771] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 09/09/2018] [Accepted: 01/29/2019] [Indexed: 11/11/2022]
Abstract
OBJECTIVE To evaluate changes in quality of care after implementing an adapted safe childbirth checklist (SCC) in Chiapas, Mexico. METHODS A convergent mixed-methods study was conducted among 447 women in labor who attended a rural community hospital between September 1, 2016, and June 30, 2017. Logistic regression analysis was used to evaluate adherence to evidence-based practices over time, adjusting for provider. Participants were surveyed about their perceptions of care after hospital discharge. A purposefully sampled subgroup also completed in-depth interviews. Thematic analysis was performed to evaluate perceptions of care. RESULTS 384 (85.9%) women were attended by staff that used the adapted SCC during delivery. Of these, 221 and 28 completed the hospital discharge survey and in-depth interview, respectively. Adherence with offering a birth companion (odds ratio [OR] 3.06, 95% CI 1.40-6.68), free choice of birth position (2.75, 1.21-6.26), and immediate skin-to-skin contact (4.53, 1.97-10.39) improved 6-8 months after implementation. Participants' perceived quality of care improved over time. Provider communication generated positive perceptions. Reprimanding women for arriving in early labor or complaining of pain generated negative perceptions. CONCLUSION Use of the adapted SCC improved quality of care through increased adherence with essential and respectful delivery practices.
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Affiliation(s)
- Rose L Molina
- Department of Obstetrics and Gynecology, Beth Israel Deaconess Medical Center, Boston, MA, USA.,Division of Women's Health, Department of Medicine, Brigham and Women's Hospital, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA
| | - Jimena Villar
- Department of Sexual and Reproductive Rights, Geneva Foundation for Medical Education and Research, Geneva, Switzerland
| | - Andrea Reyes
- Compañeros En Salud, Ángel Albino Corzo, Chiapas, Mexico
| | - James Elliott
- School of Public Health, Boston University, Boston, MA, USA
| | | | | | | | | | - Hugo Flores
- Harvard Medical School, Boston, MA, USA.,Compañeros En Salud, Ángel Albino Corzo, Chiapas, Mexico.,Division of Global Health Equity, Department of Medicine, Brigham and Women's Hospital, Boston, MA, USA
| | - Katherine E A Semrau
- Harvard Medical School, Boston, MA, USA.,Division of Global Health Equity, Department of Medicine, Brigham and Women's Hospital, Boston, MA, USA.,Ariadne Labs, Boston, MA, USA
| | - Daniel Palazuelos
- Harvard Medical School, Boston, MA, USA.,Partners In Health, Boston, MA, USA.,Division of Global Health Equity, Department of Medicine, Brigham and Women's Hospital, Boston, MA, USA
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Amanuel H, Palazuelos D, Reyes A, Montaño M, Flores H, Molina RL. "Morir En Camino": Community Narratives about Childbirth Care in Rural Chiapas. Glob Public Health 2018; 14:396-406. [PMID: 30146951 DOI: 10.1080/17441692.2018.1512143] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
This anthropological study explores why more women in the rural Sierra Madre region of Chiapas, Mexico birth at home rather than at the hospital. Between January and May of 2014, the primary investigator conducted in-depth, semi-structured interviews with twenty-six interlocutors: six parteras (home birth attendants), nine pregnant women, four mothers, four healthcare providers, and three local government leaders. Participant observation occurred in the health clinic, participants' homes, and other spaces in a community with a population of 1,188 people. Drawing from narrative analysis, the findings suggest that women face structural obstacles to accessing high-quality childbirth care, which lead them to give birth at home instead of the hospital. These obstacles include financial barriers in obtaining facility-based care and poor quality of care, such as mistreatment in the facility. The study highlights the importance of centreing community narratives in healthcare programming in order to bridge the implementation gap between women in rural communities, healthcare workers, and policymakers.
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Affiliation(s)
- Hanna Amanuel
- a African Studies Centre , Oxford University , Oxford , UK
| | - Daniel Palazuelos
- b Division of Global Health Equity , Brigham and Women's Hospital , Boston , MA , USA.,c Harvard Medical School , Boston , MA , USA.,d Partners In Health Mexico , Chiapas , Mexico
| | | | | | - Hugo Flores
- b Division of Global Health Equity , Brigham and Women's Hospital , Boston , MA , USA.,d Partners In Health Mexico , Chiapas , Mexico
| | - Rose L Molina
- c Harvard Medical School , Boston , MA , USA.,e Department of Obstetrics and Gynecology , Beth Israel Deaconess Medical Center , Boston , MA , USA.,f Division of Women's Health , Brigham and Women's Hospital , Boston , MA , USA
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Aguilar-Hernández JA, Urías-Estrada JD, López-Soto MA, Barreras A, Plascencia A, Montaño M, González-Vizcarra VM, Estrada-Angulo A, Castro-Pérez BI, Barajas R, Rogge HI, Zinn RA. Evaluation of isoquinoline alkaloid supplementation levels on ruminal fermentation, characteristics of digestion, and microbial protein synthesis in steers fed a high-energy diet. J Anim Sci 2016; 94:267-74. [DOI: 10.2527/jas.2015-9376] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Esquivel AL, Pérez-Ramos J, Cisneros J, Herrera I, Rivera-Rosales R, Montaño M, Ramos C. The effect of obesity and tobacco smoke exposure on inflammatory mediators and matrix metalloproteinases in rat model. Toxicol Mech Methods 2014; 24:633-43. [PMID: 25141943 DOI: 10.3109/15376516.2014.956911] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Obesity is characterized by hypertrophy of adipose tissue and chronic obstructive pulmonary disease (COPD) by lung damage; both diseases are associated with systemic low-grade inflammation. There are no animal models combining obesity and COPD; therefore, these diseases were induced simultaneously in rats to analyze their effects on the expression of inflammatory mediators and enzymes involved in lung tissue remodeling. Obesity was induced with sucrose (30%) for 4 months concomitant with tobacco smoke exposure (20 cigarettes/day, 5 days/wk) for the last 2 months. Were evaluated: body weight, abdominal fat, dyslipidemia, glucose tolerance test (GTT), histology, inflammatory mediators with qPCR and enzyme-linked immunosorbent assay, matrix metalloproteinases (MMP-2), MMP-9, MMP-12, TIMP-1 and TIMP-2 through qRT-PCR, and MMP-2 and MMP-9 by gelatin zymography. The rats on a sucrose diet exhibited increased body weight, abdominal fat, triglycerides, GTT, and plasma levels of insulin, adiponectin, leptin, resistin, IL-6, IL-1β, tumor necrosis factor-α (TNF-α) and IFN-γ, upregulated lung IL-6, IL-1β, TNF-α and IFN-γ, showing hyperplastic bronchial and alveolar epithelium. The animals exposed to sucrose and tobacco smoke exhibited decreased body weight, abdominal fat and plasma levels of leptin, resistin, IL-1β and IFN-γ, reducing inflammation but showing emphysematous lesions. Expression of gelatinases and MMP-12 augmented in the rats exposed to tobacco smoke alone or combined with sucrose. Zymography showed prominent gelatinases activity in all the experimental groups. These results suggest that simultaneous exposure to sucrose and tobacco smoke decreases inflammation but results in emphysematous lesions similar to those observed with tobacco smoke exposure, suggesting that obesity does not confer any protective effect against lung damage.
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Affiliation(s)
- Ana Laura Esquivel
- Doctorado en Ciencias Biológicas y de la Salud, Universidad Autónoma Metropolitana Xochimilco-Iztapalapa-Cuajimalpa , Mexico, DF , Mexico
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Ramos C, Pedraza-Chaverri J, Becerril C, Cisneros J, González-Ávila G, Rivera-Rosales R, Sommer B, Medina-Campos ON, Montaño M. Oxidative stress and lung injury induced by short-term exposure to wood smoke in guinea pigs. Toxicol Mech Methods 2013; 23:711-22. [DOI: 10.3109/15376516.2013.843113] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Montaño M, Zimmer KE, Dahl E, Berg V, Olsaker I, Skaare JU, Murk AJ, Ropstad E, Verhaegen S. Effects of mixtures of persistent organic pollutants (POPs) derived from cod liver oil on H295R steroidogenesis. Food Chem Toxicol 2011; 49:2328-35. [PMID: 21722693 DOI: 10.1016/j.fct.2011.06.034] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2011] [Revised: 06/15/2011] [Accepted: 06/15/2011] [Indexed: 10/18/2022]
Abstract
Crude cod liver oil and liver oil supplements are consumed as a source of vitamin A, D and polyunsaturated fatty acids; during winter and early pregnancy. Crude cod liver oil however constitutes a considerable source of persistent organic pollutants (POPs). This paper aimed at characterizing and quantifying the influence of POP mixtures extracted from three different steps in the cod liver oil industrial process on hormone production and the expression of steroidogenesis-related genes in H295R cells. Exposure to extracts from crude cod liver oil and from its industrial waste increased progesterone (P4), cortisol (Cort), testosterone (T) and estradiol (E2) production; and among others, the expression of MC2R, CYP11B1 and HSD3B2 genes. Observed effects after exposure to pharmaceutical cod liver oil extract were considerably lower. The type of effects on gene expression and hormone production were similar to those induced by forskolin and PCBs, the latter being the major contaminants within the extracts. Additional research is required to further unveil the mechanisms behind the observed steroidogenic effects and to assess whether the potential risk might outweigh the potential benefits of crude and processed cod liver oil consumption.
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Affiliation(s)
- M Montaño
- Department of Environment and Agro-biotechnologies, Centre de Recherche Public - Gabriel Lippmann, 41, rue de Brill, L4422 Belvaux, Grand-Duchy of Luxembourg, Luxembourg.
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Alvarez EG, Pinos-Rodríguez JM, Aguilar U, Espinoza S, Montaño M, Torrentera N, Rodriguez J. Effects of exogenous fibrolytic enzymes on intake, duodenal flow, and digestion in steers fed diets with whole or cracked Pima cottonseed. ACTA AGR SCAND A-AN 2010. [DOI: 10.1080/09064702.2010.482594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Plascencia A, Alvarez EG, Montaño M, Salinas-Chavira J, Zinn RA. Effects of Dietary Calcium Levels on Growth-performance and Digestive Function in Cattle Fed a High-fat Finishing Diet. Journal of Applied Animal Research 2009. [DOI: 10.1080/09712119.2009.9707055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
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Ulloa-Arvizu R, Gayosso-Vázquez A, Ramos-Kuri M, Estrada F, Montaño M, Alonso R. Genetic analysis of Mexican Criollo cattle populations. J Anim Breed Genet 2008; 125:351-9. [DOI: 10.1111/j.1439-0388.2008.00735.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Sauma A, Quiroga R, Brockmann C, Montaño M, Flores G, Barrenechea JP. Successful replantation following an accidental forearm amputation. Case report and review of the literature. Acta Chir Belg 2002; 102:126-30. [PMID: 12051086 DOI: 10.1080/00015458.2002.11679279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
We report a patient who suffered an accidental complete amputation of the right forearm followed by a successful replantation and comment on the indications and management of macro-replantations of the upper limbs. This is the first time that a successful surgical procedure of this nature has been performed in Bolivia, with no post-operative complications and excellent long-term functional recovery.
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Affiliation(s)
- A Sauma
- Department of Surgery and Unit of Physical Therapy, Centro Médico Quirúrgico Boliviano Belga, Cochabamba, Bolivia
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Guo X, Lin HM, Lin Z, Montaño M, Sansores R, Wang G, DiAngelo S, Pardo A, Selman M, Floros J. Surfactant protein gene A, B, and D marker alleles in chronic obstructive pulmonary disease of a Mexican population. Eur Respir J 2001; 18:482-90. [PMID: 11589345 DOI: 10.1183/09031936.01.00043401] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Chronic obstructive pulmonary disease (COPD) is characterized by chronic inflammation. It is most likely the result of complex interactions of environmental and genetic factors. Because pulmonary surfactant components play important roles in normal lung function, innate host defence, and inflammation in the lung, this study investigated the hypothesis that the surfactant protein genes are involved in certain cases of COPD. Genotype analysis of surfactant protein (SP)-A, SP-B, SP-B-linked microsatellite, and SP-D marker alleles was performed in patients with COPD (n=97) and smoker (n=82) or nonsmoker (n=99) controls. Univariate and multiple logistic regression analyses were performed. The regression analysis results between COPD and smokers revealed several COPD susceptibility alleles (AA62_A, B1580_C, D2S388_5), based on an odds ratio (OR >2.5). The predictive ability of this model for developing COPD is good (c=0.926). Allele-allele (B1580_C and D2S388_5) and allele-environment (i.e. smoking) interactions were detected. When smoker controls were compared to nonsmoker controls, marker D2S388 5 appeared to be smoking-independent (p=0.874), whereas marker alleles AA62_A (p=0.045) and B1580_5 (p=0.007) were smoking-dependent. Males were at higher risk (OR=6.05, p=0.001), and smoking (>50 packs x yr(-1)) increased risk (OR=5.38, p=0.007). Males and alleles of loci flanking SP-B were associated with more severe cases (forced expiratory volume in one second/forced vital capacity < or = 40%). The present results indicate that the surfactant protein alleles may be useful in chronic obstructive pulmonary disease by either predicting the disease in a subgroup and/or by identifying disease subgroups that may be used for therapeutic intervention. These observations should now be confirmed in a larger study, designed according to strict epidemiological criteria.
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Affiliation(s)
- X Guo
- Dept of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey 17033, USA
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Ramos C, Montaño M, García-Alvarez J, Ruiz V, Uhal BD, Selman M, Pardo A. Fibroblasts from idiopathic pulmonary fibrosis and normal lungs differ in growth rate, apoptosis, and tissue inhibitor of metalloproteinases expression. Am J Respir Cell Mol Biol 2001; 24:591-8. [PMID: 11350829 DOI: 10.1165/ajrcmb.24.5.4333] [Citation(s) in RCA: 288] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Idiopathic pulmonary fibrosis (IPF) is a chronic lung disorder characterized by fibroblast proliferation and extracellular matrix accumulation. However, studies on fibroblast growth rate and collagen synthesis have given contradictory results. Here we analyzed fibroblast growth rate by a formazan-based chromogenic assay; fibroblast apoptosis by in situ end labeling (ISEL) and propidium iodide staining; percent of alpha-smooth muscle actin (alpha-SMA) positive cells by fluorescence-activated cell sorter; and alpha1-(I) collagen, transforming growth factor (TGF)-beta1, collagenase-1, gelatinases A and B, and tissue inhibitor of metalloproteinase (TIMP)-1, -2, -3, and -4 expression by reverse transcriptase/polymerase chain reaction in fibroblasts derived from IPF and control lungs. Growth rate was significantly lower in IPF fibroblasts compared with controls (13.3 +/- 38.5% versus 294.6 +/- 57%, P < 0.0001 at 13 d). Conversely, a significantly higher percentage of apoptotic cells was observed in IPF-derived fibroblasts (ISEL: 31.9 +/- 7.0% versus 15.5 +/- 7.6% from controls; P < 0.008). alpha-SMA analysis revealed a significantly higher percentage of myofibroblasts in IPF samples (62.8 +/- 25.2% versus 14.8 +/- 11.7% from controls; P < 0.01). IPF fibroblasts were characterized by an increase in pro-alpha1-(I) collagen, TGF-beta1, gelatinase B, and all TIMPs' gene expression, whereas collagenase-1 and gelatinase A expression showed no differences. These results suggest that fibroblasts from IPF exhibit a profibrotic secretory phenotype, with lower growth rate and increased spontaneous apoptosis.
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Affiliation(s)
- C Ramos
- Instituto Nacional de Enfermedades Respiratorias, Mexico DF, Mexico
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18
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Vázquez de Lara L, Becerril C, Montaño M, Ramos C, Maldonado V, Meléndez J, Phelps DS, Pardo A, Selman M. Surfactant components modulate fibroblast apoptosis and type I collagen and collagenase-1 expression. Am J Physiol Lung Cell Mol Physiol 2000; 279:L950-7. [PMID: 11053032 DOI: 10.1152/ajplung.2000.279.5.l950] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
During lung injury, fibroblasts migrate into the alveolar spaces where they can be exposed to pulmonary surfactant. We examined the effects of Survanta and surfactant protein A (SP-A) on fibroblast growth and apoptosis and on type I collagen, collagenase-1, and tissue inhibitor of metalloproteinase (TIMP)-1 expression. Lung fibroblasts were treated with 100, 500, and 1,000 microg/ml of Survanta; 10, 50, and 100 microg/ml of SP-A; and 500 microg/ml of Survanta plus 50 microg/ml of SP-A. Growth rate was evaluated by a formazan-based chromogenic assay, apoptosis was evaluated by DNA end labeling and ELISA, and collagen, collagenase-1, and TIMP-1 were evaluated by Northern blotting. Survanta provoked fibroblast apoptosis, induced collagenase-1 expression, and decreased type I collagen affecting mRNA stability approximately 10-fold as assessed with the use of actinomycin D. Collagen synthesis and collagenase activity paralleled the gene expression results. SP-A increased collagen expression approximately 2-fold and had no effect on collagenase-1, TIMP-1, or growth rate. When fibroblasts were exposed to a combination of Survanta plus SP-A, the effects of Survanta were partially reversed. These findings suggest that surfactant lipids may protect against intraluminal fibrogenesis by inducing fibroblast apoptosis and decreasing collagen accumulation.
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Floros J, Lin HM, García A, Salazar MA, Guo X, DiAngelo S, Montaño M, Luo J, Pardo A, Selman M. Surfactant protein genetic marker alleles identify a subgroup of tuberculosis in a Mexican population. J Infect Dis 2000; 182:1473-8. [PMID: 11023470 DOI: 10.1086/315866] [Citation(s) in RCA: 121] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2000] [Revised: 06/06/2000] [Indexed: 11/03/2022] Open
Abstract
Pulmonary surfactant and its components are essential for normal lung function and are involved in local host defense. Surfactant protein (SP)-A and SP-D bind to and modulate phagocytosis of Mycobacterium tuberculosis by macrophages. Frequency comparisons of SP marker alleles in tuberculosis patients and healthy control subjects (tuberculin-skin test positive or general population) were performed. Regression analyses of the tuberculosis and the tuberculin-skin test positive groups revealed, on the basis of odds ratios, tuberculosis susceptibility (DA11_C and GATA_3) and protective (AAGG_2) marker alleles. Similarly, between tuberculosis patients and general population control subjects, susceptibility 1A(3), 6A(4), and B1013_A and protective AAGG_1, and AAGG_7 marker alleles were observed. Moreover, interactions were seen between alleles 6A(2) and 1A(3) (P=.0064) and between 1A(3) and B1013_A (P=. 036). The findings indicate a possible involvement of SP alleles in tuberculosis pathogenesis.
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Affiliation(s)
- J Floros
- Dept. of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, Hershey, PA 17033, USA.
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González-Avila G, Iturria C, Vadillo-Ortega F, Ovalle C, Montaño M. Changes in matrix metalloproteinases during the evolution of interstitial renal fibrosis in a rat experimental model. Pathobiology 2000; 66:196-204. [PMID: 9732233 DOI: 10.1159/000028023] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The aim of the present study was to analyze the matrix metalloproteinase (MMP) activity during the evolution of interstitial renal fibrosis in a rat experimental model of unilateral ureteral obstruction. The interstitial type I collagenase and the gelatinolytic activities were analyzed by radiolabeled substrate degradation. Interstitial collagenase activity was low at all times while gelatinolytic activity increased on day 6 of evolution, with a decrease in activity from this point. The use of organomercurials revealed the presence of latent enzyme in all cases. Normal kidney samples contained MMP-9 in both active and proenzyme forms as revealed by zymography. On day 3 MMP-9 dimers appeared, and increased activity was observed until day 6. A decrease in the gelatinolytic activity was detected from days 9-15 of evolution. This observation was confirmed by Western blot analysis that revealed the presence of proMMP-9 mainly from days 6-12. Tissue inhibitor of metalloproteinase-1 (TIMP-1) was also detected alone and in combination with proMMP-1 and MMP-1, particularly from days 6-15 of evolution. The presence of MMP-9 and MMP-1 was detected in the cytoplasm of cortical tubular cells by immunohistochemistry, with no difference between the experimental and the normal kidneys. There was also an increase in collagen concentration from day 3 after surgery that increased during the entire evolution of the experimental model. This work reveals that the decrease in the MMP-9 and MMP-1 enzymatic activity, due to their interaction with TIMP-1 and to the lack of activation of the latent forms, may participate in the excessive collagen deposit during the evolution of experimental interstitial renal fibrosis.
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Affiliation(s)
- G González-Avila
- Department of Immunology, Insituto Nacional de Enfermedades Respiratorias, México
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21
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Guo X, Lin HM, Lin Z, Montaño M, Sansores R, Wang G, DiAngelo S, Pardo A, Selman M, Floros J. Polymorphisms of surfactant protein gene A, B, D, and of SP-B-linked microsatellite markers in COPD of a Mexican population. Chest 2000; 117:249S-50S. [PMID: 10843936 DOI: 10.1378/chest.117.5_suppl_1.249s-a] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Affiliation(s)
- X Guo
- Department of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
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22
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Becerril C, Pardo A, Montaño M, Ramos C, Ramírez R, Selman M. Acidic fibroblast growth factor induces an antifibrogenic phenotype in human lung fibroblasts. Am J Respir Cell Mol Biol 1999; 20:1020-7. [PMID: 10226073 DOI: 10.1165/ajrcmb.20.5.3288] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Acidic fibroblast growth factor (FGF-1), a prototype member of the heparin-binding growth factor family, influences proliferation, differentiation, and protein synthesis in different cell types. However, its possible role on lung extracellular matrix (ECM) metabolism has not been evaluated. In this study we examined the effects of FGF-1 and FGF-1 plus heparin on type I collagen, collagen-binding stress protein HSP47, interstitial collagenase (matrix metalloproteinase [MMP]-1), gelatinase A, and tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2 expression by normal human lung fibroblasts. Heparin was used because it enhances the biologic activities of FGF-1. Fibroblasts were exposed either to 20 ng/ml FGF-1 plus 100 micrograms/ml heparin for 48 h or to FGF-1 or heparin alone. Messenger RNA (mRNA) expression was analyzed by Northern blot. Collagen synthesis was evaluated by digestion of [3H]collagen with bacterial collagenase, MMP-1 by Western blot, and gelatinolytic activities by zymography. Our results show that FGF-1 induced collagenase mRNA expression, which was strongly enhanced when FGF-1 was used with heparin. Likewise, both FGF-1 and FGF-1 plus heparin reduced by 70 to 80% the expression of type I collagen transcript, in part through effect on pro-alpha1(I) collagen mRNA stability. A downregulation of HSP47 gene expression was also observed. Synthesis of collagen and collagenase proteins paralleled gene expression results. FGF-1 activities were abolished with genistein, a tyrosine kinase inhibitor. Neither FGF-1 nor FGF-1 plus heparin affected the expression of TIMP-1, TIMP-2, and gelatinase A. These findings demonstrate that FGF-1, mostly in the presence of heparin, upregulates collagenase and downregulates type I collagen expression that might have a protective role in avoiding collagen accumulation during lung ECM remodeling.
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Affiliation(s)
- C Becerril
- Instituto Nacional de Enfermedades Respiratorias; and Facultad de Ciencias, Universidad Nacional Autónoma de México, México DF, México
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23
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Ramirez JE, Alvarez EG, Montaño M, Shen Y, Zinn RA. Influence of dietary magnesium level on growth-performance and metabolic responses of Holstein steers to laidlomycin propionate. J Anim Sci 1998; 76:1753-9. [PMID: 9690629 DOI: 10.2527/1998.7671753x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
We used 216 Holstein steers (151 kg) in a 262-d trial to evaluate the influence of dietary magnesium level (.19, .25, and .32%) and laidlomycin propionate (LP; 0 vs 11 ppm, air-dry basis) on growth performance and NE value of the diet. During the initial 112 d of the trial, LP increased (P < .01) ADG (6.3%) and feed efficiency (4.2%). From d 112 until slaughter, LP increased (P < .05) ADG (9.7%) and feed efficiency (4.5%). Across the 262-d feeding period, LP supplementation enhanced (P < .01) ADG (8.9%) and feed efficiency (6.3%). There was an interaction (P < .05) between dietary Mg and LP on NE value of the diet. The enhancement in NE value of the diets owing to LP with .19, .25, and .32% dietary Mg were .5, 3.0, and 5.9%, respectively. Six Holstein steers (302 kg) were used in a 6 x 6 Latin square experiment to evaluate treatment effects on characteristics of ruminal and total tract digestion. There were no treatment interactions (P > .10) on site and extent of digestion of OM, starch, and N. Supplemental Mg increased (quadratic effect, P < .10) ruminal OM digestion. Neither LP nor dietary Mg level affected (P > .10) ruminal digestion of starch and feed N. Supplemental LP decreased (15%, P < .05) ruminal microbial efficiency. Total tract digestion of OM and N increased (linear effect, P < .01) with increasing dietary Mg level. There were interactions between LP and dietary Mg level on ruminal soluble-Mg concentration (linear effect, P < .01) and Mg absorption (quadratic effect, P < .05). Apparent total tract Mg digestion increased owing to LP (P < .01) and dietary Mg level (linear effect, P < .01). There were no treatment effects (P > .10) on ruminal pH. Dietary Mg level did not influence (P > .10) ruminal VFA concentrations or molar proportions. Supplemental LP increased (14%; P < .10) total ruminal VFA concentration but did not affect (P > .10) VFA molar proportions. We conclude that LP will increase daily weight gain and feed efficiency of calf-fed Holstein steers and that this response may be enhanced by increasing dietary Mg level.
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Affiliation(s)
- J E Ramirez
- Desert Research and Extension Center, University of California, El Centro 92243, USA
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24
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Abstract
One hundred twenty crossbred steers (294 kg, initially) were used in a 141-d finishing trial. Four concentrations (8, 16, 24, and 32% of diet DM) of cottonseed meal (CSM, prepressed solvent-extracted) replaced steam-flaked corn in a corn-based finishing diet. Increasing level of CSM decreased ADG (linear component, P < .10), feed efficiency (linear component, P < .01), and dietary NE (linear component, P < .01). Observed dietary NE was 99% of expected at 8 and 16% CSM but 95% of expected at higher levels of inclusion (linear component, P < .05). Level of CSM did not influence (P > .10) dressing percentage, longissimus area, fat thickness, or retail yield. Eight Holstein steers (285 kg) were used in a replicated 4 x 4 Latin square design to evaluate treatment effects on characteristics of digestion. Ruminal digestibility of OM decreased (linear component, P < .05) as CSM increased, although ruminal digestibility of starch and feed N were not affected (P > .10). Ruminal escape protein from CSM was 58%. Total tract starch digestion was not altered (P > .10), but total tract digestibility of OM and GE decreased (linear component, P < .05) and digestion of N increased (linear component, P < .01) as CSM replaced steam-flaked corn. The ratio of observed to expected DE value of the diets was similar across CSM levels, averaging .99. Thus, comparative DE value of CSM was not affected by level of inclusion, averaging 3.32 Mcal/kg. We conclude that the NEm and NEg values of CSM are 1.88 and 1.24 Mcal/kg, respectively, and in close agreement with tabular values. However, CSM should not exceed 16% of DMI, because higher levels may depress cattle performance and replacement value of CSM.
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Affiliation(s)
- R A Zinn
- Department of Animal Science, Imperial Valley Agricultural Center, University of California, El Centro 92243, USA
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Barrios R, Pardo A, Ramos C, Montaño M, Ramirez R, Selman M. Upregulation of acidic fibroblast growth factor during development of experimental lung fibrosis. Am J Physiol 1997; 273:L451-8. [PMID: 9277459 DOI: 10.1152/ajplung.1997.273.2.l451] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Fibroblast proliferation and extracellular matrix accumulation are crucial in the pathogenesis of lung fibrosis. Fibroblast growth factor (FGF)-1 participates in both processes, but its role in lung fibrogenesis has not been evaluated. We analyzed the expression of FGF-1 and of FGF receptor (FGFR) in a model of lung fibrosis induced in rats with paraquat plus hyperoxia. Experimental and control animals were killed at 48 h and 2, 4, and 8 wk, and the lungs were studied by in situ hybridization, immunohistochemistry, and Northern blot. In normal lungs, scattered macrophages contained FGF-1. In contrast, at all times examined, the injured lungs exhibited FGF-1 transcript and the immunoreactive protein, mainly in alveolar epithelial cells and macrophages. In advanced fibrotic lesions, fibroblasts also appeared stained. Northern blot corroborated the upregulation of FGF-1 mRNA. FGFR was not observed in normal lungs, whereas it was strongly increased in the damaged lungs and was virtually immunolocalized in the same cell types as the corresponding ligand. These findings suggest that FGF-1 and FGFR are actively synthesized during the development of pulmonary fibrosis.
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Affiliation(s)
- R Barrios
- Department of Pathology, Baylor College of Medicine, Houston, Texas 77030, USA
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Sansores RH, Abboud RT, Becerril C, Montaño M, Ramos C, Vanda B, Selman ML. Effect of exposure of guinea pigs to cigarette smoke on elastolytic activity of pulmonary macrophages. Chest 1997; 112:214-9. [PMID: 9228379 DOI: 10.1378/chest.112.1.214] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
STUDY OBJECTIVE To determine the effect of exposure to cigarette smoke on the elastolytic activity of guinea pigs' alveolar macrophages (AMs), and to compare elastolytic activity of AMs obtained by BAL with that of lung macrophages (LMs) obtained from minced lung tissue. METHODS AMs were obtained by BAL from seven adult guinea pigs exposed to cigarette smoke for 5 d/wk during 6 weeks, as well as from age-matched control guinea pigs. From each animal, one lung was used to obtain LMs by mincing and teasing the lung, followed by enzymatic digestion and isolation of mononuclear cells by Hypaque-Ficoll separation. The other lung was inflated and fixed to quantitate emphysema by the destructive index (DI). Elastolytic activity (microgram of elastin degraded by 10(6) macrophages) was determined at 24, 48, and 72 h, by culturing AMs and LMs (1 x 10(6) cells in 1 mL of medium) in 3H-elastin-coated wells. RESULTS In animals exposed to cigarette smoke, the total number of BAL cells (8.6+/-2.1 x 10(6)) and DI (21.8+/-8.1) were significantly higher than in nonexposed animals (6.4+/-1.8 x 10(6), p<0.05 for cells, and 12.1+/-4.1, p<0.01 for DI). Elastolytic activity of AMs from smoke-exposed guinea pigs was significantly higher at 24, 48, and 72 h than elastolytic activity of AMs from control animals (19.0+/-9.4 vs 10.0+/-5.3, p<0.05 at 72 h). Likewise, elastolytic activity of LMs was significantly higher in exposed than nonexposed guinea pigs (11.8+/-7.7 vs 7.4+/-5.0 at 72 h, p<0.05). Elastolytic activity of LMs was not significantly different from elastolytic activity of AMs, both in exposed guinea pigs (11.8+/-7.7 vs 19.0+/-9.4 at 72 h) and nonexposed animals (7.4+/-5.0 vs 10.0+/-5.3 at 72 h). CONCLUSIONS These results indicate that elastolytic activity of both AMs and LMs of guinea pigs increases significantly after exposure to cigarette smoke and that AMs and LMs have similar elastolytic activities.
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Affiliation(s)
- R H Sansores
- Instituto Nacional de Enfermedades Respiratorias, Mexico, DF
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Zinn RA, Alvarez E, Mendez M, Montaño M, Ramirez E, Shen Y. Influence of dietary sulfur level on growth performance and digestive function in feedlot cattle. J Anim Sci 1997; 75:1723-8. [PMID: 9222827 DOI: 10.2527/1997.7571723x] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Using ammonium sulfate, three levels of dietary S (.15, .20, and .25%, DM basis) were evaluated in a finishing trial with 108 yearling crossbred heifers (384 kg). The basal diet contained (DM basis) 4% alfalfa hay, 6% sudangrass hay, 74% steam-flaked corn, 4% yellow grease, 6% cane molasses, and 6% protein-mineral supplement. Increasing dietary S decreased ADG (quadratic effect, P < .10), DMI (linear effect, P < .10), feed efficiency (quadratic effect, P < .10), diet NE (quadratic effect, P < .10), and longissimus muscle area (linear effect, P < .05). Six Holstein steers (218 kg) with cannulas in the rumen and proximal duodenum were used to evaluate treatment effects on characteristics of digestion. Treatment effects on ruminal and total tract digestion of OM and N were small (P > .10). However, ruminal digestion of ADF and starch was slightly lower (quadratic effect, P < .10), and postruminal digestion of ADF and starch was correspondingly greater (quadratic effect, P < .05) with supplemental S. Dietary S level did not influence (P > .10) ruminal synthesis of microbial N. Increasing dietary S did not influence (P > .10) ruminal pH or lactic acid. Increasing S decreased molar proportions of acetate (quadratic effect, P < .10) and increased molar proportions of propionate (linear effect, P < .10). We conclude that S in excess of .20% of dietary DM may have detrimental effects on growth performance and dietary NE. Excessive dietary S may also compromise carcass merit by decreasing longissimus muscle area.
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Affiliation(s)
- R A Zinn
- Department of Animal Science, University of California, El Centro 92243, USA
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Selman M, Montaño M, Ramos C, Vanda B, Becerril C, Delgado J, Sansores R, Barrios R, Pardo A. Tobacco smoke-induced lung emphysema in guinea pigs is associated with increased interstitial collagenase. Am J Physiol Lung Cell Mol Physiol 1996; 271:L734-43. [PMID: 8944716 DOI: 10.1152/ajplung.1996.271.5.l734] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
We examined the expression of interstitial collagenase and its enzymatic activity in lung damage induced by tobacco smoke. Guinea pigs were exposed to the smoke of 20 cigarettes per day from 1-8 wk. Age-matched guinea pigs were used as controls. At 6 and 8 wk of smoke exposure, lungs exhibited interstitial and peribronchiolar inflammation and moderate emphysematous changes. In situ hybridization of injured lungs revealed patchy expression of collagenase mRNA mainly in macrophages but also in alveolar epithelial and interstitial cells. Immunoreactive protein was detected in alveolar macrophages and in the alveolar walls and interstitium. Collagenolytic activity increased beginning in the 4th wk of exposure (0.7 +/- 0.43 micrograms collagen degraded/mg collagen incubated relative to 0.23 +/- 0.14 in controls; P < 0.05). At 6 and 8 wk, values were 0.85 +/- 0.34 and 0.98 +/- 0.33 compared with 0.25 +/- 0.11 and 0.26 +/- 13 in controls (P < 0.005 and 0.001). Collagen concentration decreased from 50.7 +/- 8.5 mg/g dry wt in control lungs to 40.2 +/- 5.0 and 42.9 +/- 6.0 at 6 and 8 wk of exposure, respectively (P < 0.05). These results strongly suggest that increased interstitial collagen degradation plays a role in the development of lung emphysema.
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Affiliation(s)
- M Selman
- Instituto Nacional de Enfermedades Respiratorias, Tlalpan Mexico DF
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29
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Abstract
Four Holstein steers (222 kg) with cannulas in the rumen and proximal duodenum were used in a crossover design experiment to evaluate the energy and protein value of dehydrated poultry excreta (DPE). Dietary treatments contained (DM basis) 4% alfalfa hay, 8% sudangrass hay, 49% flaked barley, 8% cane molasses, 3% yellow grease, .8% urea, 1.4% limestone, .3% mineral salt, and .4% chromic oxide, plus 25% of either tapioca pellets or DPE. The DPE contained 42% ash and 27% CP (6% true protein). Substituting DPE for tapioca decreased the DE value of the diet (P < .01). The estimated DE value of the DPE was 1.36 Mcal/kg (.34 Mcal NEm/ kg). There were no treatment effects (P > .10) on microbial N flow to the small intestine or ruminal microbial efficiency (grams of microbial N/kilogram of OM fermented). The addition of DPE increased (P < .05) the flow of non-ammonia and feed N to the small intestine. The estimated ruminal escape N value of DPE was 22%, although very little of this was true protein. Dehydrated poultry excreta did not increase (P > .10) flow of alpha-amino N to the small intestine. Ruminal degradability of uric acid was 96%. Total tract true digestibility of N in DPE was 84%. It is concluded that the NE value of DPE is markedly overestimated in current tables of feeding standards. Less than 10% of the N in DPE escapes the rumen as true protein N.
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Affiliation(s)
- R A Zinn
- Imperial Valley Agricultural Center, University of California, El Centro 92243, USA
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Sansores RH, Ramirez-Venegas A, Pérez-Padilla R, Montaño M, Ramos C, Becerril C, Gaxiola M, Paré P, Selman M. Correlation between pulmonary fibrosis and the lung pressure-volume curve. Lung 1996; 174:315-23. [PMID: 8843057 DOI: 10.1007/bf00176190] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The severity of pulmonary fibrosis is the main prognostic factor for survival of patients with interstitial lung diseases (ILD). Unfortunately, lung biopsy, which is the best method to assess fibrosis quantitatively, is done only once during the evolution of the disease. In this study we analyzed the relationship between the degree of fibrosis and the exponential constant k, derived from the lung pressure-volume curve (LPVC) in 33 patients with chronic ILD, 19 with pigeon breeder's disease (PBD), and 14 with idiopathic pulmonary fibrosis (IPF). Pulmonary function tests, including the LPVC, were obtained before biopsy. A semiquantitative histologic assessment of the severity of fibrosis was performed on lung tissues. All patients showed a decrease of total lung capacity, residual volume, compliance, and Pao2. The mean value of the constant k was 0.08 +/- 0.06. When expressed as a percent of normal values, 25 patients exhibited values of k lower than 70% of predicted; of the remaining 8 patients whose values were above 70% of predicted, 7 had PBD and only one IPF. On morphologic analysis, 19 patients displayed more than 50% fibrosis. No significant correlations were found between the extent of the lesion or severity of lung fibrosis and the conventional pulmonary function tests. By contrast, a moderate but significant correlation was found between k and the severity of lung fibrosis (r = -0.38, p < 0.05). These findings show that the shape of the LPVC, represented by the constant k, predicts the degree of lung fibrosis and could be useful in the clinical assessment and follow-up of patients with ILD.
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Affiliation(s)
- R H Sansores
- Instituto Nacional de Enfermedades Respiratorias, México City, Mexico
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31
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Abstract
One hundred twenty medium-frame crossbred steers (364 kg) were used in a 106-d feedlot trial to compare the feeding value of Condor, a hulless barley (HB), with Leduc, a conventional covered barley (CB). Dietary treatments consisted of a finishing diet containing 77% grain (DM basis) as 1) steam-flaked corn (SFC); 2) dry-rolled HB (DRB-H); 3) steam-flaked HB (SFB-H); 4) dry-rolled CB (DRB-C); and 5) steam-flaked CB (SFB-C). Feed intake was lower (8.6%, P < .01) for HB than for CB. Diet NE was greater for HB than for CB (P < .01) and for SFB than for DRB (P < .01). Incidence of liver abscess was greater for DRB than for SFB (239%, P < .05) and for HB than for CB (167%, P < .10). Diet NE were greater (P < .10) for SFC than for barley treatments. Treatment effects on characteristics of digestion were evaluated using five Holstein steers (202 kg) with cannulas in the rumen and proximal duodenum. There were barley variety x grain processing interactions on ruminal digestion of OM (P < .10), ADF (P < .05), and starch (P < .05). Ruminal OM digestion increased (9.0%) with steam flaking HB and decreased slightly (1.9%) with steam flaking CB. Ruminal digestion of starch was enhanced more dramatically (21.5 vs 8.4%, respectively) with steam flaking HB than with CB. Steam flaking decreased ruminal ADF digestion of HB only slightly (6.2%), whereas with CB the decrease was more dramatic (54.3%). Ruminal degradable N was greater (P < .10) for CB than for HB and for DRB than for SFB (19.8%, P < .05). Estimates of ruminal degradable N in DRB-H, SFB-H, DRB-C, and SFB-C were 69.7, 53.9, 78.5, and 65.0%, respectively. Postruminal digestion of OM (P < .01), starch (P < .05), and N (P < .10) were greater for HB than for CB. Steam flaking barley increased (P < .01) postruminal N digestibility. Total tract digestibility of OM (P < .01), ADF (P < .05), starch (P < .01), and energy (P < .01) were greater for HB than for CB. Digestibility of ADF in barley hulls was only 6.4%. Steam flaking increased (P < .01) total tract digestibility of starch. Ruminal digestibility of OM and feed N was lower (P < .01) for SFC than for barley diets. Ruminal pH was lower (P < .10) for HB than for CB and for SFB than for DRB (P < .01). Ruminal propionate was higher (24.1%, P < .01), and methane was lower (17.9%, P < .01) for HB than for CB.
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Affiliation(s)
- R A Zinn
- Imperial Valley Agricultural Center, University of California, El Centro 92243, USA
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Barquín N, Chou P, Ramos C, Montaño M, Pardo A, Selman M. Increased expression of intercellular adhesion molecule 1, CD11/CD18 cell surface adhesion glycoproteins and alpha 4 beta 1 integrin in a rat model of chronic interstitial lung fibrosis. Pathobiology 1996; 64:187-92. [PMID: 9031327 DOI: 10.1159/000164034] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The expression of the intercellular adhesion molecule 1 (ICAM-1), and the integrins CD49, CD11b/c, and CD11a (LFA-1 alpha chain) was analyzed in an experimental model of pulmonary fibrosis. Adult rats were exposed to 75% oxygen during 10 weeks, and to 2.0 mg/kg of paraquat twice weekly. Rats were sacrificed at 2 days, and at 2 and 10 weeks after the first injection of paraquat. Lungs were fixed in 4% paraformaldehyde and used for histology and immunohistochemistry. At 2 days the lungs showed a diffuse inflammation composed of a mixed polymorphonuclear and mononuclear cell infiltrate. Afterwards, the inflammatory process was predominantly mononuclear, and an increasing fibroblast proliferation was observed. Early inflammatory events (48 h) correlated with a moderate increased expression of ICAM-1, LFA, and CD11b/c in epithelial cells as well as a pronounced expression of ICAM-1 and CD11b/c in macrophages. At 2 and 10 weeks, there was a progressive increased expression of CD11b/c and ICAM-1 by macrophages, as well as of LFA in epithelial cells, and of ICAM-1 and CD49 by epithelial and interstitial cells. Lymphocytes showed a slight increased expression of LFA at 2 weeks, and of CD49 at 2 and 10 weeks. These results suggest that macrophages expressing ICAM-1, CD11b/c, and CD49 are involved in the earlier and late phases of the disease whereas fibroblast and epithelial cells expressing ICAM-1 and CD49 might play a role in the cell interactions involved in the fibrotic phase.
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Affiliation(s)
- N Barquín
- Department of Pathology, Children's Memorial Hospital, Chicago, Ill., USA
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33
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Rojas-Valencia L, Montiel F, Montaño M, Selman M, Pardo A. Expression of a 2.8-kb PDGF-B/c-sis transcript and synthesis of PDGF-like protein by human lung fibroblasts. Chest 1995; 108:240-5. [PMID: 7606965 DOI: 10.1378/chest.108.1.240] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The replication of fibroblasts is thought to be controlled by exogenous growth factors mainly secreted by macrophages and epithelial cells. However, under standard culture conditions, lung fibroblasts are able to produce several growth factors, suggesting an autocrine pathway of proliferation. In this work, we examined the expression of platelet-derived growth factor (PDGF-A) and PDGF-B-messenger RNA (mRNAs) by fibroblasts derived from four human adult normal lungs and from two fibrotic lungs. Northern blot analysis showed that both normal and idiopathic pulmonary fibrosis (IPF)-derived fibroblasts expressed a 2.8 PDGF-B/c-sis mRNA. This transcript was also observed as a minor form in human osteosarcoma cell line, used as control, which predominantly expressed a 4.0-kb PDGF-B mRNA. In two fibroblast cell lines, one fibrotic and one normal, the 4.0-kb transcript was also observed but was always weaker than the 2.8-kb mRNA. PDGF-A mRNA was not detected. By immunofluorescence, lung fibroblasts exhibited intracytoplasmic PDGF-like protein. Likewise, conditioned media from normal and IPF lung fibroblasts stimulated 3H-thymidine incorporation in BALB/c-3T3 cells that was significantly inhibited by anti-PDGF antibody. These results show that in vitro, some human lung fibroblasts express PDGF-B/c-sis mRNA, mainly an alternate 2.8-kb transcript, and produce PDGF-like protein.
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Affiliation(s)
- L Rojas-Valencia
- Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico, DF
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Abstract
We have evaluated, in an experimental model of silicosis in guinea pigs, if the presence of collagenolytic activity in bronchoalveolar lavage (BAL) fluid reflects the collagen catabolism in lung parenchyma. We measured simultaneously BAL collagenase activity, using as substrate [3H]type I collagen, and lung collagenolytic activity by the tissue pellet assay. Animals (n = 30) were instilled intratracheally with 50 mg of quartz DQ-12 and sacrificed 15, 30, and 60 days after silica administration. Guinea pigs instilled with saline solution were used as controls. Our results showed that lung parenchymal collagenolytic activity was present in all experimental and normal guinea pigs. There were no statistical differences between silicotic and normal animals at 15 and 30 days. At 60 days, however, a significant decrease in tissue collagenolytic activity was observed in silicotic animals (161 +/- 100 vs. 400 +/- 152 units of collagenase activity; p < 0.001). In contrast, BAL collagenolytic activity was revealed only in 7 of 10 silicotic animals at 15 days and 30 days, and in 4 of 10 at 60 days. Normal guinea pigs did not exhibit BAL collagenase activity. BAL and tissue collagenase activity from each experimental animal were analyzed by straight line regression and no significant relationship was observed (r = 0.082; p = 0.87). This suggests that BAL collagenolytic activity does not reflect lung tissue collagen turnover.
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Affiliation(s)
- M Montaño
- Instituto Nacional de Enfermedades Respiratorias, Tlalpan, México DF
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Pardo A, Selman M, Ramírez R, Ramos C, Montaño M, Stricklin G, Raghu G. Production of collagenase and tissue inhibitor of metalloproteinases by fibroblasts derived from normal and fibrotic human lungs. Chest 1992; 102:1085-9. [PMID: 1395748 DOI: 10.1378/chest.102.4.1085] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Several experiments have demonstrated low collagenolytic activity during the development of pulmonary fibrosis. In order to determine if fibroblasts play a role in this alteration, procollagenase and tissue inhibitor of metalloproteinases (TIMP) were quantified in fibroblasts derived from 12 human lung specimens (normal = 6, idiopathic pulmonary fibrosis [IPF] = 6). Under basal conditions, three cell strains from normal and three from fibrotic lung specimens did not synthesize collagenase and a similar number of normal and IPF-derived fibroblast strains produced the enzyme. However, the rate of enzyme synthesis among normal and fibrotic collagenase producing fibroblasts exhibited significant differences. Thus, whereas normal fibroblasts produced more than 300 ng/ml, fibrotic lung fibroblasts secreted approximately half of this amount (115 +/- 67 ng/ml). Phorbol myristate acetate (PMA) enhanced collagenase production in all of the 12 lung fibroblast lines tested. In four IPF fibroblasts, PMA increased collagenase secretion close to those of normal stimulated lung fibroblasts; however, a lower induction was observed in cell strains from two fibrotic lung specimens. There was a wide variation in TIMP production both in normal and fibrotic lung fibroblasts, and no statistically significant difference was observed. Under basal conditions, TIMP levels ranged from 329 to 16,911 ng/ml in normal lung cells, and from 377 to 17,557 in fibrotic lung fibroblasts. PMA induced a severalfold increase in all cell lines. These results suggest that there are subpopulations of lung fibroblasts with different potential to produce collagenase and TIMP in vitro, and that the predominance of low collagenase-producing subsets may contribute to the development of fibrosis.
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Affiliation(s)
- A Pardo
- Facultad de Ciencias, Universidad Nacional Autónoma de México
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36
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Selman M, Pardo A, Barquín N, Sansores R, Ramírez R, Ramos C, Montaño M, Stricklin G. Collagenase and collagenase inhibitors in bronchoalveolar lavage fluids. Chest 1991; 100:151-5. [PMID: 1647937 DOI: 10.1378/chest.100.1.151] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Collagenase, collagenolytic activity and tissue inhibitor of metalloproteinases were evaluated in bronchoalveolar lavage from 25 patients with hypersensitivity pneumonitis and four control subjects. Patients were followed between two and three years, after which they were classified as "healed," "improved," or "worsened." In control samples, immunoreactive collagenase was not detected. The enzyme was present in four of seven patients who healed, six of ten patients who improved, and four of eight patients who worsened. There was no relationship between the presence or absence of BAL collagenase or its concentration and the evolution of the disease. Latent collagenolytic activity was detected only in 5 of the 14 patients who displayed immunoreactive collagenase. Regarding collagenase inhibitor, TIMP was present in BAL fluid from all patients and normal subjects. Although the highest values were found in two cases who healed or improved, there was not a statistically significant difference among the three groups of patients, neither between patients nor control subjects. These findings suggest that at least in HP, the presence of collagenase, collagenolytic activity, or TIMP in BAL fluid is not associated with the prognosis of the disease.
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Affiliation(s)
- M Selman
- Instituto Nacional de Enfermedades Respiratorias, Facultad de Ciencias, Universidad Nacional Autónoma de México
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37
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Montaño M, Ramos C, González G, Vadillo F, Pardo A, Selman M. Lung collagenase inhibitors and spontaneous and latent collagenase activity in idiopathic pulmonary fibrosis and hypersensitivity pneumonitis. Chest 1989; 96:1115-9. [PMID: 2553344 DOI: 10.1378/chest.96.5.1115] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
In order to analyze the mechanisms involved in the decreased collagenolytic activity previously observed in interstitial lung fibrosis, we studied the inhibitory collagenase activity and the latent activable collagenase in lung samples from five patients with IPF, six with HP, and three control subjects. Our results showed that in both diseases, the inhibitor levels were significantly higher than in control subjects. Findings suggest that in IPF low amounts of collagenase plus excessive enzyme-inhibitors may be operating to decrease collagen catabolism. In contrast, HP lungs seem to contain adequate amounts of the enzyme but higher levels of inhibitors play a role in the abnormal degradation observed in some patients.
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Affiliation(s)
- M Montaño
- Instituto Nacional de Enfermedades Respiratorias SSA, Mexico City, Mexico
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38
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Selman M, Montaño M, Ramos C, Barrios R, Pérez-Tamayo R. Experimental pulmonary fibrosis induced by paraquat plus oxygen in rats: a morphologic and biochemical sequential study. Exp Mol Pathol 1989; 50:147-66. [PMID: 2707380 DOI: 10.1016/0014-4800(89)90027-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Changes in lung structure and collagen metabolism were studied at 1, 2, 3, 4, 6, and 8 weeks in a model of pulmonary fibrosis induced in rats with paraquat plus hyperoxia. Morphologic examination of the lungs revealed that the earliest lesions consisted of severe and irreversible endothelial and alveolar epithelial cell damage. Afterward, an inflammatory process took place, initially dominated by polymorphonuclear leukocytes and then by mononuclear cells, but with the constant presence of granulocytes. From the fourth week on there were fibroblast proliferation and a moderate increase of mast cells. In the early stages alveolitis was focal, but from the second week the lungs were diffusely affected with severe distortion of the architecture. Collagen content was moderately increased in the first 2 weeks and then showed a progressive increment until the end of the experiment. Collagen synthesis was significantly elevated from the fourth week, coinciding with interstitial fibroblast proliferation, although there were some animals that showed increased collagen production from the first week. Collagenolytic activity occurred in 3 stages: at 2 weeks there was increased collagen degradation, at 3, 4, and 6 weeks the values showed a trimodal behavior, and at 8 weeks almost all experimental rats presented an important decrease of collagenolysis. Thus, the development of lung fibrosis was associated first with increased rates of collagen synthesis and later with a decrease of collagen degradation.
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Affiliation(s)
- M Selman
- Departamento de Enfermedades Crónico-Degenerativas, Instituto Nacional de Enfermedades Respiratorias SSA, Mexico DF, Mexico
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Vadillo-Ortega F, González-Avila G, Chevez P, Abraham CR, Montaño M, Selman-Lama M. A latent collagenase in human aqueous humor. Invest Ophthalmol Vis Sci 1989; 30:332-5. [PMID: 2536647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
It has been suggested that the trabecular meshwork may be involved in the pathogenesis of open-angle glaucoma, and some authors have pointed out that disorders of the extracellular matrix components may play a role; nevertheless, nothing is known about the normal metabolism of connective tissue molecules in this particular tissue. We recently initiated some studies in this field and have focused on the in vitro effects of aqueous humor on collagen metabolism. We report the finding of a latent collagenase of low molecular weight in aqueous humor obtained from cataractous patients; the enzyme was identified through several methods, including its in vitro activity against radiolabelled type I collagen and additionally with a zymogram technique. It was partially characterized by high-performance liquid chromatography.
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Affiliation(s)
- F Vadillo-Ortega
- Departamento de Bioquímica, Instituto Nacional de Perinatología, SSA, Mexico, D.F
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40
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Abstract
In spite of several studies, both in vivo and in vitro, the pathogenesis of silicosis remains unclear, mainly in those mechanisms related to fibrogenesis. In this study, we analyzed the concentration, biosynthesis, and degradation of collagen in silica-treated rats 7, 15, 30, 45, and 60 days after instillation. Our results showed a significant increase in collagen content and biosynthesis from the 15th day onward. However, our most remarkable finding was related to collagenolytic activity. In this sense, the silicotic rats presented a trimodal behavior: some animals showed an increased degradation, others had similar values to those of the controls, and others exhibited a decrease of collagenolytic activity. Altogether, these results suggest that collagen deposition in silicotic lungs is due to a rise in biosynthesis and, at least in some animals, to a decrease in degradation. Nevertheless, the steps of collagenolysis must be studied in more detail.
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Affiliation(s)
- C Ramos
- Instituto Nacional de Enfermedades Respiratorias, SSA, México
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41
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Abstract
We studied lung collagen metabolism in 18 patients with hypersensitivity pneumonitis to determine if changes at this level could explain the different clinical courses followed by these patients. Collagen concentration, biosynthesis and degradation were measured in lung tissue samples obtained before treatment. Four patients healed, eight improved and six did not improve or worsened. All patients who healed showed an important increase in collagenolysis; patients who improved had normal or high values, but significantly less than those obtained in patients who healed. Finally, five out of the six patients who did not improve or worsened had a significant decrease in degradation. These findings support the notion that a diminution of local collagenolysis may play a role in the progression to fibrosis in some patients with hypersensitivity pneumonitis and can also be a useful tool to predict the prognosis of this disease.
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Affiliation(s)
- M Selman
- Clinical Research Division, Instituto Nacional de Enfermedades Respiratorias, Mexico City, Mexico
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Abstract
Despite several studies both in vitro and in vivo, the pathogenesis of pulmonary fibrosis is unclear and some findings related to the biochemistry of collagen are controversial. Collagen metabolism was studied in 11 patients with idiopathic pulmonary fibrosis and in six control subjects. There was an increase in collagen concentration (mean 327 (SD 76) compared with control values of 185 (18) micrograms/mg dry weight, p less than 0.001), normal values for biosynthesis (mean 2.2% (0.8%) v 2.08% (0.5%), and a noteworthy decrease in collagenolytic activity (mean 0.07 (0.04) v 0.23 (0.04) micrograms of collagen degraded per mg of collagen incubated, p less than 0.001). These results suggest that an alteration in enzymatic breakdown of collagen plays an important role in the maintenance and progression of interstitial fibrosis in this disease.
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Abstract
The duration of the pulmonary paraquat toxicity-enhancement effect of O2 has been examined in Wistar rats. In one experiment, various groups of normal animals were given a single dose (5 mg/kg body wt) of paraquat and after different periods were exposed to continuous breathing of normobaric 74% O2 in airtight chambers until dead or up to 10 days. In a reverse experiment, a large number of rats were first exposed for 6 days to continuous breathing of normobaric 74% O2 and were then separated into various groups which received a single dose of paraquat (5 mg/kg body wt) after various periods of breathing normal air, ranging from 0 to 96 hr. The extent of pulmonary damage in both experiments was evaluated by histologic examination and by biochemical determination of total collagen content of the lungs. It was found that the duration of the pulmonary damage induced by paraquat that is enhanced by continuous breathing of high O2 concentration lasts 24 to 48 hr. It was also observed that 12 to 24 hr after paraquat administration and continuous breathing of high O2 concentration pulmonary lesions are severe and extensive, and in animals surviving 6 or more days there was also incipient interstitial fibrosis. The reverse sequence of treatment (O2 + paraquat) resulted in no mortality and no pulmonary lesions. Additional controls treated with each of the pulmonary toxins alone also revealed no lung changes.
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Abstract
We have produced experimental diffuse interstitial pulmonary fibrosis in rats with a combination of low and repeated doses of paraquat plus continuous exposure to normobaric 74% O2 in the breathing air for several weeks. Pulmonary fibrosis was evaluated histologically and biochemically, through the determination of total collagen content in the lung. Our procedure is characterized by low initial mortality, the development of extensive distortion of the pulmonary architecture, and the presence of severe and diffuse interstitial fibrosis. The model was compared with bleomycin-induced pulmonary fibrosis in the same rat strain, in which the process is focal and leaves most of the lung unaffected. We conclude that lung damage produced by the combination of low doses of paraquat plus normobaric 74% O2 concentration in the breathing air is an adequate experimental model of diffuse interstitial pulmonary fibrosis as it occurs in many of the human cases of this condition.
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