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Freitas Cardoso de Azevedo M, Barros LL, Fernandes Justus F, Oba J, Soares Garcia K, de Almeida Martins C, de Sousa Carlos A, Arruda Leite AZ, Miranda Sipahi A, Queiroz NSF, Omar Mourão Cintra Damião A. Active tuberculosis in inflammatory bowel disease patients: a case-control study. Therap Adv Gastroenterol 2023; 16:17562848231179871. [PMID: 37435180 PMCID: PMC10331078 DOI: 10.1177/17562848231179871] [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] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Accepted: 05/17/2023] [Indexed: 07/13/2023] Open
Abstract
Background/Aims Anti-tumor necrosis factor (anti-TNF) drugs have been the mainstay therapy for moderate to severe inflammatory bowel disease (IBD) over the past 25 years. Nevertheless, these drugs are associated with serious opportunistic infections like tuberculosis (TB). Brazil is ranked among the 30 countries with the highest incidence of TB in the world. This study aimed at identifying risk factors for the development of active TB and describing clinical characteristics and outcomes in IBD patients followed at a tertiary referral center in Brazil. Methods We conducted a retrospective, case-control study between January 2010 and December 2021. Active TB cases in IBD patients were randomly matched 1:3 to controls (IBD patients with no previous history of active TB) according to gender, age, and type of IBD. Design This was a retrospective, case-control study. Results A total of 38 (2.2%) cases of TB were identified from 1760 patients under regular follow-up at our outpatient clinics. Of the 152 patients included in the analysis (cases and controls), 96 (63.2%) were male, and 124 (81.6%) had Crohn's disease. Median age at TB diagnosis was 39.5 [interquartile range (IQR) 30.8-56.3]. Half of the active TB cases were disseminated (50%). Overall, 36 patients with TB (94.7%) were being treated with immunosuppressive medications. Of those, 31 (86.1%) were under anti-TNF drugs. Diagnosis of TB occurred at a median of 32 months after the first dose of anti-TNF (IQR 7-84). In multivariate analysis, IBD diagnosis older than 17 years and anti-TNF therapy were significantly associated with the development of TB (p < 0.05). After the TB treatment, 20 (52.7%) patients received anti-TNF therapy, and only one developed 'de novo' TB 10 years after the first infection. Conclusions TB remains a significant health problem in IBD patients from endemic regions, especially those treated with anti-TNFs. In addition, age at IBD diagnosis (>17 years old) was also a risk factor for active TB. Most cases occur after long-term therapy, suggesting a new infection. The reintroduction of anti-TNFs agents after the anti-TB treatment seems safe. These data highlight the importance of TB screening and monitoring in IBD patients living in endemic areas.
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Affiliation(s)
| | - Luísa Leite Barros
- Department of Gastroenterology, University of
São Paulo School of Medicine, São Paulo, Brazil
| | - Filipe Fernandes Justus
- Department of Gastroenterology, University of
São Paulo School of Medicine, São Paulo, Brazil
| | - Jane Oba
- Department of Gastroenterology, University of
São Paulo School of Medicine, São Paulo, Brazil
| | - Karoline Soares Garcia
- Department of Gastroenterology, University of
São Paulo School of Medicine, São Paulo, Brazil
| | | | | | | | - Aytan Miranda Sipahi
- Department of Gastroenterology, University of
São Paulo School of Medicine, São Paulo, Brazil
| | - Natália Sousa Freitas Queiroz
- Health Sciences Graduate Program, Pontifícia
Universidade Católica do Paraná (PUCPR), Curitiba, BrazilIBD Center, Santa
Cruz Hospital, Curitiba, Brazil
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Garcia KS, de Azevedo MFC, Carlos ADS, Barros LL, Oba J, Sobrado Junior CW, Sipahi AM, Alves ODDC, Navarro-Rodriguez T, Parra RS, Chebli JMF, Chebli LA, Flores C, Vieira A, do Ceará CDA, Queiroz NSF, Damião AOMC. Efficacy of Early Optimization of Infliximab Guided by Therapeutic Drug Monitoring during Induction-A Prospective Trial. Biomedicines 2023; 11:1757. [PMID: 37371853 DOI: 10.3390/biomedicines11061757] [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] [Received: 04/13/2023] [Revised: 06/09/2023] [Accepted: 06/12/2023] [Indexed: 06/29/2023] Open
Abstract
Therapeutic drug monitoring (TDM) during induction therapy with anti-tumor necrosis factor drugs has emerged as a strategy to optimize response to these biologics and avoid undesired outcomes related to inadequate drug exposure. This study aimed to describe clinical, biological, and endoscopic remission rates at six months in Brazilian inflammatory bowel disease (IBD) patients following a proactive TDM algorithm guided by IFX trough levels (ITL) and antibodies to IFX (ATI) levels during induction, at week six. A total of 111 IBD patients were prospectively enrolled, excluding those previously exposed to the drug. ITL ≥ 10 μg/mL was considered optimal. Patients with suboptimal ITL (<10 µg/mL) were guided according to ATI levels. Those who presented ATI ≤ 200 ng/mL underwent dose intensification in the maintenance phase, and patients with ATI > 200 ng/mL discontinued IFX. In our study, proactive TDM was associated with persistence in the IFX rate at six months of 82.9%. At that time, rates of clinical, biological, and endoscopic remission in patients under IFX treatment were 80.2%, 73.9%, and 48.1%, respectively. Applying a simplified TDM-guided algorithm during induction seems feasible and can help improve patients' outcomes in clinical practice.
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Affiliation(s)
- Karoline Soares Garcia
- Department of Gastroenterology, University of São Paulo, School of Medicine, São Paulo 05403-000, Brazil
| | | | - Alexandre de Sousa Carlos
- Department of Gastroenterology, University of São Paulo, School of Medicine, São Paulo 05403-000, Brazil
| | - Luísa Leite Barros
- Department of Gastroenterology, University of São Paulo, School of Medicine, São Paulo 05403-000, Brazil
| | - Jane Oba
- Department of Gastroenterology, University of São Paulo, School of Medicine, São Paulo 05403-000, Brazil
| | | | - Aytan Miranda Sipahi
- Department of Gastroenterology, University of São Paulo, School of Medicine, São Paulo 05403-000, Brazil
| | | | - Tomás Navarro-Rodriguez
- Department of Gastroenterology, University of São Paulo, School of Medicine, São Paulo 05403-000, Brazil
| | - Rogério Serafim Parra
- Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto 14049-900, Brazil
| | | | - Liliana Andrade Chebli
- University Hospital of the Federal University of Juiz de Fora, Juiz de Fora 36038-330, Brazil
| | - Cristina Flores
- Crohn's and Colitis Reference Center, Rio Grande do Sul 90560-002, Brazil
| | - Andrea Vieira
- Irmandade da Santa Casa de Misericórdia de São Paulo, São Paulo 01221-010, Brazil
| | | | - Natália Sousa Freitas Queiroz
- Health Sciences Graduate Program, Pontifícia Universidade Católica do Paraná (PUCPR), Curitiba 80215-901, Brazil
- IBD Center, Santa Cruz Hospital, Curitiba 80420-090, Brazil
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Martins CDA, Garcia KS, Queiroz NSF. Multi-utility of therapeutic drug monitoring in inflammatory bowel diseases. Front Med (Lausanne) 2022; 9:864888. [PMID: 35966848 PMCID: PMC9366431 DOI: 10.3389/fmed.2022.864888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Accepted: 07/04/2022] [Indexed: 11/14/2022] Open
Abstract
Inflammatory bowel disease (IBD) treatment targets have progressed over time from clinical response to clinical and endoscopic remission. Several data have shown a positive correlation between serum biologic drug concentrations and favorable therapeutic outcomes. Therapeutic drug monitoring (TDM) has evolved as an important approach for optimizing the use of immunobiologics, especially antitumor necrosis factor therapy, in patients with IBD. The use of TDM is supported by medical societies and IBD experts in different contexts; however, challenges remain due to knowledge gaps that limit the widespread use of it. The aim of this review is to assess the role of TDM in IBD, focusing on the implementation of this strategy in different scenarios and demonstrating the multi-utility aspects of this approach in clinical practice.
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Affiliation(s)
| | - Karoline Soares Garcia
- Department of Gastroenterology, University of São Paulo School of Medicine, São Paulo, Brazil
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Queiroz NSF, Garcia KS, Miranda EF, Kotze PG. Patient-Reported Outcomes Measures in Perianal Fistulizing Crohn's Disease. Rev Recent Clin Trials 2022; 17:RRCT-EPUB-122860. [PMID: 35469573 DOI: 10.2174/1574887117666220425125424] [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] [Received: 09/04/2021] [Revised: 01/06/2022] [Accepted: 01/10/2022] [Indexed: 06/14/2023]
Abstract
Perianal fistulizing Crohn's disease (PFCD) is a disabling complication of Crohn's disease (CD) that can significantly impact on patients' quality of life (QoL) and often requires multidisciplinary care. Clinical trials assessing the efficacy of medical and surgical interventions for fistulas usually evaluate outcomes such as closure of fistula tracts or radiologic healing. However, these traditional outcome assessments fail in capturing the impact of the disease from patients' perspectives. In this context, regulatory authorities have increasingly encouraged the inclusion of validated patient-reported outcomes (PRO) that assess disease activity and reveal how a patient functions and feels. This recent trend towards patient-centered care aims to ensure that improvements in efficacy outcomes are accompanied by meaningful benefits to patients. The aim of this review is to discuss currently available PRO measures (PROMS) for the assessment of PFCD to provide to physicians appropriate tools aiming to optimize patient care and disseminate the use of these instruments in clinical practice.
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Affiliation(s)
| | - Karoline Soares Garcia
- Department of Gastroenterology, University of São Paulo School of Medicine, São Paulo, Brazil
| | - Eron Fabio Miranda
- Colorectal Surgery Unit, Pontifícia Universidade Católica do Paraná (PUCPR), Curitiba, Brazil
| | - Paulo Gustavo Kotze
- Colorectal Surgery Unit, Pontifícia Universidade Católica do Paraná (PUCPR), Curitiba, Brazil
- Health Sciences Postgraduate Program, Pontifícia Universidade Católica do Paraná (PUCPR), Curitiba, Brazil
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Garcia KS, Facas BP, Machado MB, Teixeira FV, Avedano L, Lönnfors S, Hossne RS, Peyrin-Biroulet L, Queiroz NSF. Biosimilar knowledge and viewpoints among Brazilian inflammatory bowel disease patients. Therap Adv Gastroenterol 2021; 14:17562848211013249. [PMID: 34046083 PMCID: PMC8135202 DOI: 10.1177/17562848211013249] [Citation(s) in RCA: 2] [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] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 03/25/2021] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND In this analysis we aimed to describe Brazilian inflammatory bowel disease (IBD) patients' knowledge and perceptions regarding biosimilars and compare with viewpoints from non-Brazilian patients. METHODS An online survey consisting of 19 questions was made available by the European Federation of Crohn's and Ulcerative Colitis Associations between July 2018 and December 2018. Only respondents who had heard of biosimilars were asked to respond to all of the questions. RESULTS A total of 102 Brazilian IBD patients responded to the survey. The majority (78.4%) of patients had been exposed to anti-tumor-necrosis-factor drugs and 63.4% of them had heard of biosimilars. Brazilian respondents worried significantly more about biosimilars being less effective than the originator (62.5% versus 47.9%, p value 0.03) and molecular differences between biosimilars and originators (53.1% versus 31.8, p value 0.001) as compared with non-Brazilian IBD patients. The majority of Brazilian (75%) and non-Brazilian (64.1%) respondents thought that the lower cost of biosimilars should not come before their safety and efficacy (p value 0.09). In addition, 79.1% of Brazilian respondents believed that the arrival of biosimilars will have an impact on the management of IBD. CONCLUSIONS Brazilian patients reported higher rates of misconceptions regarding biosimilars than non-Brazilian IBD patients. Although patients still worry about different aspects regarding biosimilars, they also tend to be confident that biosimilars will have an impact on the management of their disease. With the recent approval of many biosimilars in Brazil and the imminent widespread use of these drugs, our data raise awareness for the need of providing patient education to prevent negative expectations toward switching to biosimilars.
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Affiliation(s)
| | - Bianca Pocopetz Facas
- Department of Gastroenterology, University of São Paulo School of Medicine, São Paulo, Brazil
| | - Marta Brenner Machado
- Department of Gastroenterology, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Brazilian Crohn’s Disease and Ulcerative Colitis Association (Associação Brasileira de Colite Ulcerativa e Doença de Crohn: ABCD), Porto Alegre, Brazil
| | - Fábio Vieira Teixeira
- Gastrosaúde: IBD Clinic, Marília, SP, Brazil,Brazilian Crohn’s Disease and Ulcerative Colitis Association (Associação Brasileira de Colite Ulcerativa e Doença de Crohn: ABCD)
| | - Luisa Avedano
- European Federation of Crohn’s and Ulcerative Colitis Association (EFCCA), Brussels, Belgium, UK
| | - Sanna Lönnfors
- European Federation of Crohn’s and Ulcerative Colitis Association (EFCCA), Brussels, Belgium, UK
| | - Rogério Saad Hossne
- Paulista State University (UNESP): Botucatu Medical School, São Paulo, Brazil
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Garcia KS, Moutinho BD, de Azevedo MFC, Queiroz NSF, Milani LR, Sanches LN, Barros LL, Oba J, Carlos ADS, Damião AOMC, Sipahi AM. Recovery from COVID-19 Pneumonia in a Patient with Acute Severe Colitis. Inflamm Intest Dis 2020; 5:93-97. [PMID: 32984404 PMCID: PMC7493790 DOI: 10.1159/000508161] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Accepted: 04/23/2020] [Indexed: 12/26/2022] Open
Abstract
Introduction The coronavirus disease 2019 (COVID-19) pandemic has increased concern regarding SARS-CoV-2 infection in inflammatory bowel disease (IBD) patients, especially those on immunosuppressive therapies or with active disease. There are limited reports describing the clinical features of COVID-19 in an IBD population, and the impact of immunosuppression on the severity of the infection remains unclear. Case Report A 33-year-old female patient with a long history of ulcerative colitis, poorly controlled, was admitted with COVID-19 a few days after being discharged from the hospital for treatment of acute severe ulcerative colitis. High-risk factors for COVID-19 complications, i.e., high-dose steroids (40 mg prednisone) and severe active disease, were present at admission. Despite the development of extensive pulmonary involvement, the patient had a favorable outcome. Discussion Management of IBD patients during the COVID-19 pandemic has been challenging. Measures to minimize the potential risk of SARS-CoV-2 infection, including strict social distancing and self-isolation, in the IBD population have been recommended, especially for high-risk patients. Although steroid tapering and persistence of biologics are advised by professional groups, the best treatment strategy for IBD patients presenting a flare during the outbreak has yet to be defined.
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Affiliation(s)
- Karoline Soares Garcia
- Division of Gastroenterology and Hepatology, Department of Gastroenterology, Hospital das Clínicas, School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Bruna Damásio Moutinho
- Division of Gastroenterology and Hepatology, Department of Gastroenterology, Hospital das Clínicas, School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Matheus Freitas Cardoso de Azevedo
- Division of Gastroenterology and Hepatology, Department of Gastroenterology, Hospital das Clínicas, School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Natalia Sousa Freitas Queiroz
- Department of Gastroenterology, Hospital das Clínicas, School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Luciane Reis Milani
- Division of Gastroenterology and Hepatology, Department of Gastroenterology, Hospital das Clínicas, School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Lucas Navarro Sanches
- Division of Gastroenterology and Hepatology, Department of Gastroenterology, Hospital das Clínicas, School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Luisa Leite Barros
- Division of Gastroenterology and Hepatology, Department of Gastroenterology, Hospital das Clínicas, School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Jane Oba
- Division of Gastroenterology and Hepatology, Department of Gastroenterology, Hospital das Clínicas, School of Medicine, University of São Paulo, São Paulo, Brazil.,Instituto da Criança e do Adolescente, Hospital das Clínicas, School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Alexandre de Sousa Carlos
- Division of Gastroenterology and Hepatology, Department of Gastroenterology, Hospital das Clínicas, School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Aderson Omar Mourão Cintra Damião
- Division of Gastroenterology and Hepatology, Department of Gastroenterology, Hospital das Clínicas, School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Aytan Miranda Sipahi
- Division of Gastroenterology and Hepatology, Department of Gastroenterology, Hospital das Clínicas, School of Medicine, University of São Paulo, São Paulo, Brazil.,Laboratory of Clinical and Experimental Gastroenterology (LIM-07), Hospital das Clínicas, School of Medicine, University of São Paulo, São Paulo, Brazil
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Hatje V, Macedo SM, de Jesus RM, Cotrim G, Garcia KS, de Queiroz AF, Ferreira SLC. Inorganic As speciation and bioavailability in estuarine sediments of Todos os Santos Bay, BA, Brazil. Mar Pollut Bull 2010; 60:2225-2232. [PMID: 20832088 DOI: 10.1016/j.marpolbul.2010.08.014] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2010] [Revised: 08/10/2010] [Accepted: 08/19/2010] [Indexed: 05/29/2023]
Abstract
The spatial distribution of As (total As, As (III) and As (V)) in estuarine sediments from the main tributaries of Todos os Santos Bay, BA, Brazil, was evaluated under high and low flow conditions. The concentrations of As were determined using a slurry sampling procedure with hydride generation atomic absorption spectrometry (HG-AAS). The highest concentrations were observed at estuary mouths, and exceeded conservative lower threshold value (Threshold Effects Level; TEL). Due to the oxic conditions and abundance of Mn and Fe (oxyhydr)oxides in the sediments, most inorganic arsenic in the Subaé and Paraguaçu estuaries was present as As (V). Nevertheless, the concentration of As (III) at several locations along the Jaguaripe River were also above the TEL value, suggesting that As may be toxic to biota. In the Subaé estuary, antropogenic activities are the main source of As. At the Jaguaripe and at Paraguaçu estuaries, nevertheless, natural sources of As need to be considered to explain the distribution patterns.
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Affiliation(s)
- V Hatje
- Laboratório de Oceanografia Química, Instituto de Química, UFBA, Campus Ondina, Salvador, BA, 40170-290, Brazil.
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Medina JF, Garcia KS, Mauk MD. A mechanism for savings in the cerebellum. J Neurosci 2001; 21:4081-9. [PMID: 11356896 PMCID: PMC6762711] [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] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2023] Open
Abstract
The phenomenon of savings (the ability to relearn faster than the first time) is a familiar property of many learning systems. The utility of savings makes its underlying mechanisms of special interest. We used a combination of computer simulations and reversible lesions to investigate mechanisms of savings that operate in the cerebellum during eyelid conditioning, a well characterized form of motor learning. The results suggest that a site of plasticity outside the cerebellar cortex (possibly in the cerebellar nucleus) can be protected from the full consequences of extinction and that the residual plasticity that remains can later contribute to the savings seen during relearning.
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Affiliation(s)
- J F Medina
- W. M. Keck Center for the Neurobiology of Learning and Memory, and Department of Neurobiology and Anatomy, University of Texas Medical School, Houston, Texas 77030, USA
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Medina JF, Garcia KS, Nores WL, Taylor NM, Mauk MD. Timing mechanisms in the cerebellum: testing predictions of a large-scale computer simulation. J Neurosci 2000; 20:5516-25. [PMID: 10884335 PMCID: PMC6772322] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2000] [Revised: 04/27/2000] [Accepted: 05/01/2000] [Indexed: 02/16/2023] Open
Abstract
We used large-scale computer simulations of eyelid conditioning to investigate how the cerebellum generates and makes use of temporal information. In the simulations the adaptive timing displayed by conditioned responses is mediated by two factors: (1) different sets of granule cells are active at different times during the conditioned stimulus (CS), and (2) responding is not only amplified at reinforced times but also suppressed at unreinforced times during the CS. These factors predict an unusual pattern of responding after partial removal of the cerebellar cortex that was confirmed using small, electrolytic lesions of cerebellar cortex. These results are consistent with timing mechanisms in the cerebellum that are similar to Pavlov's "inhibition of delay" hypothesis.
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Affiliation(s)
- J F Medina
- W. M. Keck Center for the Neurobiology of Learning and Memory and Department of Neurobiology and Anatomy, University of Texas Medical School, Houston, Texas 77030, USA
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Garcia KS, Steele PM, Mauk MD. Cerebellar cortex lesions prevent acquisition of conditioned eyelid responses. J Neurosci 1999; 19:10940-7. [PMID: 10594075 PMCID: PMC6784942] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023] Open
Abstract
We have used aspiration and electrolytic lesions to investigate the contributions of cerebellar cortex to the acquisition and expression of conditioned eyelid responses. We show that lesions of the anterior lobe of rabbit cerebellar cortex disrupt the timing of previously learned conditioned eyelid responses. These short-latency responses were used as an indication that the cerebellar cortex was sufficiently damaged and that the underlying pathways necessary for the expression of responses were sufficiently intact to support responses. Rabbits were subsequently trained for 15 daily sessions using a new conditioned stimulus. Whereas rabbits in which lesions had no significant effect on response timing showed rapid acquisition of appropriately timed eyelid responses to the new conditioned stimulus, animals with lesions that disrupt timing showed no significant increases in either amplitude or probability of responses. Histological analysis suggests that damage to the anterior lobe of the cerebellar cortex is necessary and sufficient to abolish timing and prevent acquisition. These data indicate that the cerebellar cortex is necessary for the acquisition of conditioned eyelid responses and are consistent with the hypotheses that (1) eyelid conditioning results in plasticity in both the anterior lobe of the cerebellar cortex and in the anterior interpositus nucleus and (2) induction of plasticity in the interpositus requires intact input from the cerebellar cortex.
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Affiliation(s)
- K S Garcia
- Department of Neurobiology, The Keck Center for the Neurobiology of Learning and Memory, University of Texas Medical School, Houston, Texas 77030, USA
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Abstract
Contradictory results have been reported regarding the effects of cerebellar cortex lesions on the expression of conditioned eyelid responses--either no effect, partial to complete abolition of responses, or disruption of response timing. This uncertainty is increased by debates regarding the region(s) of cerebellar cortex that are involved, by the likelihood that cortex lesions can inadvertently include damage to the interpositus nucleus or other pathways necessary for response expression, and by potential confounds from the degeneration of climbing fibers produced by cerebellar cortex lesions. We have addressed these issues by reversibly blocking cerebellar cortex output via infusion of the GABA antagonist picrotoxin into the interpositus nucleus. After picrotoxin infusion, conditioned responses are spared but their timing is disrupted and their amplitude diminished. In the same animals, conditioned responses were abolished by infusion of the GABA agonist muscimol and were unaffected by infusion of saline vehicle. These results are consistent with the hypothesis that (i) plasticity in the interpositus nucleus contributes to the expression of conditioned responses, as suggested by the responses seen with the cortex disconnected, and (ii) plasticity in the cerebellar cortex also contributes to conditioned response expression, as suggested by disruption of response timing.
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Affiliation(s)
- K S Garcia
- Department of Neurobiology and Anatomy, University of Texas Medical School, Houston 77030, USA
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Affiliation(s)
- M D Mauk
- W. M. Keck Center for the Neurobiology of Learning and Memory and Department of Neurobiology and Anatomy, University of Texas Medical School, Houston 77030, USA
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Eskin A, Garcia KS, Byrne JH. Information storage in the nervous system of Aplysia: specific proteins affected by serotonin and cAMP. Proc Natl Acad Sci U S A 1989; 86:2458-62. [PMID: 2538842 PMCID: PMC286932 DOI: 10.1073/pnas.86.7.2458] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [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: 01/01/2023] Open
Abstract
To identify proteins that may be involved in the induction of long-term changes in the nervous system, we investigated whether specific proteins in pleural sensory neurons of Aplysia were affected by procedures that mimic those used to produce long-term sensitization. Using two-dimensional PAGE, we found that exposure to serotonin (5-hydroxytryptamine, 5-HT) for 2 or 3 hr appeared to increase incorporation of labeled amino acids into one protein (P9) and decrease incorporation into two other proteins (P19 and P20). These effects of 5-HT were observed whether the labeled amino acid was leucine or methionine. The same proteins that were affected by 5-HT were also altered by the adenylate cyclase activator forskolin and by the 8-bromo and 8-benzylthio analogs of cAMP. Addition of Co2+ to 5-HT did not seem to affect the action of 5-HT on P9 and P20, but it did seem to block the effect of 5-HT on P19. However, the effect of analogs of cAMP on P9, P19, and P20 was not altered by inclusion of Co2+. A phorbol ester that activates protein kinase C did not appear to affect the proteins that were modified by 5-HT, but phorbol ester did appear to increase the amount of labeled amino acids incorporated into another protein (P24). To investigate the specificity of these effects for pleural ganglion neurons, we examined the effect of 3- and 6-hr treatments of 5-HT on proteins in the abdominal ganglion. 5-HT affected at least nine proteins in the abdominal ganglion. One of these proteins (P9) appeared to be the same as one altered by 5-HT in the pleural sensory neurons. However, the occurrence of some proteins and some effects of 5-HT were specific for one ganglion or the other. The identified proteins that were affected by both 5-HT and changes in cAMP may be involved in the induction of long-term changes in the nervous system of Aplysia.
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Affiliation(s)
- A Eskin
- Department of Biochemistry and Biophysical Sciences, University of Houston, TX 77004
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