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1.
Explor Neuroprotective Ther ; 3(4): 235-257, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37920444

RESUMO

Parkinson's disease (PD) is a common neurodegenerative disorder affecting aged population around the world. PD is characterized by neuronal Lewy bodies present in the substantia nigra of the midbrain and the loss of dopaminergic neurons with various motor and non-motor symptoms associated with the disease. The protein α-synuclein has been extensively studied for its contribution to PD pathology, as α-synuclein aggregates form the major component of Lewy bodies, a hallmark of PD. In this narrative review, the authors first focus on a brief explanation of α-synuclein aggregation and circumstances under which aggregation can occur, then present a hypothesis for PD pathogenesis in the peripheral nervous system (PNS) and how PD can spread to the central nervous system from the PNS via the transport of α-synuclein aggregates. This article presents arguments both for and against this hypothesis. It also presents various non-pharmacological rehabilitation approaches and management techniques for both motor and non-motor symptoms of PD and the related pathology. This review seeks to examine a possible hypothesis of PD pathogenesis and points to a new research direction focus on rehabilitation therapy for patients with PD. As various non-motor symptoms of PD appear to occur earlier than motor symptoms, more focus on the treatment of non-motor symptoms as well as a better understanding of the biochemical mechanisms behind those non-motor symptoms may lead to better long-term outcomes for patients with PD.

2.
J Spinal Cord Med ; 45(4): 622-630, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-33443465

RESUMO

OBJECTIVE: To investigate the effects of an 8-week walking training program on glycemic control, lipid profile, and inflammatory markers in individuals with chronic spinal cord injury (SCI). DESIGN: A pilot, single-group, pretest-posttest study. SETTING: A neuromuscular research laboratory. PARTICIPANTS: Eleven participants with chronic SCI. INTERVENTION: An 8-week walking training program using a treadmill, a body weight-supported system, and an assistive gait training device. OUTCOME MEASURES: Levels of glycated hemoglobin (HbA1c), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), C-reactive protein (CRP), and interleukin-6 were assessed before and after the walking training. RESULTS: Following the walking training, there was a statistically significant decrease in HbA1c level (P<0.01) of uncertain clinical significance. The lipid profile improved after training, as shown by a statistically and clinically significant increase in HDL-C level (P<0.01) and a statistically significant decrease in LDL-C level (P<0.1) of no clinical significance. The ratio of LDL-C to HDL-C was significantly reduced (P<0.01). In regard to inflammatory markers, concentrations of IL-6 showed a significant reduction after training (P=0.05) of unknown clinical significance, while those of CRP trended to decrease (P=0.13). CONCLUSION: The findings of this pilot study suggest that an 8-week walking training program may produce favorable changes in risk markers of cardiovascular disease in individuals with chronic SCI as shown by clinically meaningful improvements in HDL-C, and small changes in the right direction, but uncertain clinical significance, in HbA1c, LDL-C and IL-6. A randomized controlled trial is needed to compare the effects of walking training on these outcome measures with those of other exercise modalities suitable for this population, and to see if more prolonged exercise exposure leads to favorable parameters of significant size to justify the exercise modality.


Assuntos
Doenças Cardiovasculares , Traumatismos da Medula Espinal , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/prevenção & controle , LDL-Colesterol , Terapia por Exercício , Humanos , Interleucina-6 , Projetos Piloto , Traumatismos da Medula Espinal/complicações , Caminhada
3.
Complement Ther Clin Pract ; 39: 101169, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32379638

RESUMO

Non-motor symptoms (NMS) including sleep disorders, anxiety, depression, fatigue, and cognitive decline can significantly impact quality of life in people with PD. Qigong exercise is a mind-body exercise that shows a wide range of benefits in various medical conditions. The purpose of this study was to investigate the effect of Qigong exercise on NMS with a focus on sleep quality. Seventeen participants completed a 12-week intervention of Qigong (n = 8) or sham Qigong (n = 9). Disease severity, anxiety and depression levels, fatigue, cognition, quality of life, and other NMS of the participants were evaluated prior to the intervention and at the end of the 12-week intervention. After the intervention, both Qigong and sham-Qigong group showed significant improvement in sleep quality (p < 0.05) and overall NMS (p < 0.05). No significant difference was found between groups. Qigong exercise has the potential as a rehabilitation method for people with PD, specifically alleviating NMS in PD. However, this finding needs to be carefully considered due to the small sample size and potentially low intervention fidelity of this study.


Assuntos
Doença de Parkinson/complicações , Doença de Parkinson/reabilitação , Qigong/métodos , Qigong/psicologia , Qualidade de Vida/psicologia , Transtornos do Sono-Vigília/terapia , Sono/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Projetos de Pesquisa , Transtornos do Sono-Vigília/etiologia
4.
Integr Med Res ; 9(4): 100416, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32455108

RESUMO

BACKGROUND: Some of the most debilitating symptoms of fibromyalgia (FM) include widespread chronic pain, sleep disturbances, chronic fatigue, anxiety, and depression. Yet, there is a lack of effective self-management exercise interventions capable of alleviating FM symptoms. The objective of this study is to examine the efficacy of a 10-week daily Qigong, a mind-body intervention program, on FM symptoms. METHODS: 20 participants with FM were randomly assigned to Qigong (experimental) or sham-Qigong (control) groups, with participants blinded to the intervention allocation. The Qigong group practiced mild body movements synchronized with deep diaphragmatic breathing and meditation. The sham-Qigong group practiced only mild body movements. Both groups practiced the interventions two times per day at home, plus one weekly group practice session with a Qigong instructor. Primary outcomes were: pain changes measured by the Short-Form McGill Pain Questionnaire, a visual analog scale for pain, pressure pain threshold measured by a dolorimeter. Secondary outcomes were: the Revised Fibromyalgia Impact Questionnaire the Pittsburgh Sleep Quality Index, the Hospital Anxiety and Depression Scale and the Quality of Life Scale. RESULTS: The experimental group experienced greater clinical improvements when compared to the control group on the mean score differences of pain, sleep quality, chronic fatigue, anxiety, depression, and fibromyalgia impact, all being statistically significant at p < 0.05. CONCLUSION: Daily practice of Qigong appears to have a positive impact on the main fibromyalgia symptoms that is beyond group interaction. TRIAL REGISTRATION: ClinicalTrials.gov NCT03441997.

5.
Medicines (Basel) ; 6(1)2019 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-30669324

RESUMO

Background: Non-motor symptoms such as sleep disturbance, cognitive decline, fatigue, anxiety, and depression in Parkinson's disease (PD) impact quality of life. Increased levels of pro-inflammatory cytokines in individuals with PD have been reported, which may contribute to non-motor symptoms. A mind-body exercise, Qigong, has demonstrated benefits across different medical conditions. However, a lack of evidence causes clinicians and patients to be uncertain about the effects of Qigong in individuals with PD. This study will examine the effects of Qigong on non-motor symptoms and inflammatory status in individuals with PD. Methods: Sixty individuals with PD will be recruited. Qigong and sham Qigong group (n = 30 for each) will receive a 12-week intervention. Participants will practice their assigned exercise at home (2×/day) and attend routinely group exercise meetings. Results: Clinical questionnaires and neuropsychological tests will measure non-motor symptoms including sleep quality (primary outcome). Biomarker assays will measure inflammatory status. A two-way mixed-design analysis of variance (ANOVA) will be utilized. Conclusions: This study may generate evidence for the benefits of Qigong on non-motor symptoms of PD and the effect on inflammatory status. Findings may lead to the development of a novel, safe, and cost-effective rehabilitation approach for individuals with PD.

6.
Medicines (Basel) ; 4(2)2017 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-28930237

RESUMO

Background: Inflammatory cytokine levels are often elevated in people with Parkinson's disease (PD). People with PD often experience sleep disturbances that significantly impact quality of life. Past studies suggest inflammatory cytokines may be associated with various symptoms of PD. Benefits of Qigong, a mind-body exercise, have been shown in different neurological conditions, but there is still a lack of clinical evidence in the PD population. Methods: Ten people with PD were recruited and randomly assigned into two groups receiving six weeks of Qigong (experimental group) or sham Qigong (control group) intervention. The levels of TNF-α, IL-1ß, and IL-6 in subjects' serum and sleep quality were measured before and after the intervention. Results: After the intervention, the serum level of TNF-α in the experimental group was significantly decreased in all subjects, while the level in the control group showed a trend to increase. Qigong exercise significantly improved sleep quality at night. There was a strong correlation between changes in the level of TNF-α and sleep quality. Conclusion: Qigong exercise decreased TNF-α level in people with PD and helped improve sleep quality. TNF-α may have a potential to influence the sleep quality in people with PD.

7.
J Anat ; 225(3): 337-45, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25040358

RESUMO

The distribution, location, and spatial arrangement of mechanoreceptors are important for neural signal conciseness and accuracy in proprioceptive information required to maintain functional joint stability. The glenohumeral joint capsule and labrum are mechanoreceptor-containing tissues for which the distribution of mechanoreceptors has not been determined despite the importance of these tissues in stabilizing the shoulder. More recently, it has been shown that damage to articular mechanoreceptors can result in proprioceptive deficits that may lead to recurrent instability. Awareness of mechanoreceptor distribution in the glenohumeral joint capsule and labrum may allow preservation of the mechanoreceptors during surgical treatment for shoulder instability, and in turn retain the joint's proprioceptive integrity. For this reason, we sought to develop a neuroanatomical map of the mechanoreceptors within the capsule and labrum. We postulated that the mechanoreceptors in these tissues are distributed in a unique pattern, with mechanoreceptor-scarce regions that may be more appropriate for surgical dissection. We determined the neuroanatomical distribution of mechanoreceptors and their associated fascicles in the capsule and labrum from eight human cadaver shoulder pairs using our improved gold chloride staining technique and light microscopy. A distribution pattern was consistently observed in the capsule and labrum from which we derived a neuroanatomical map. Both tissues demonstrated mechanoreceptor-dense and -scarce regions that may be considered during surgical treatment for instability. Capsular fascicles were located in the subsynovial layer, whereas labral fascicles were concentrated in the peri-core zone. The capsular fascicles presented as a lattice network and with a plexiform appearance. Fascicles within the labrum resembled a cable structure with the fascicles running in parallel. Our findings contribute to the neuroanatomical knowledge of the two glenohumeral joint stabilizers, namely, capsule and labrum, primarily involved in the onset of shoulder instability and recurrent instability. Neuroanatomical knowledge of articular mechanoreceptors is important for (i) developing a topographical map that reflects correspondence between the joint and surrounding musculature, (ii) understanding proprioceptive deficits that are only partially restored post surgical and post rehabilitative treatment, and (iii) gaining further knowledge about articular mechanoreceptors.


Assuntos
Cápsula Articular/inervação , Mecanorreceptores/citologia , Articulação do Ombro/inervação , Adulto , Idoso , Idoso de 80 Anos ou mais , Cadáver , Feminino , Humanos , Masculino , Ilustração Médica , Pessoa de Meia-Idade , Terminações Nervosas/fisiologia , Adulto Jovem
8.
J Diabetes Res ; 2013: 965832, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23762878

RESUMO

Type 1 diabetes (T1D) is characterized by hyperglycemia due to lost or damaged islet insulin-producing ß -cells. Rodent models of T1D result in hyperglycemia, but with different forms of islet deterioration. This study focused on 1 toxin-induced and 2 autoimmune rodent models of T1D: BioBreeding Diabetes Resistant rats, nonobese diabetic mice, and Dark Agouti rats treated with streptozotocin. Immunochemistry was used to evaluate the insulin levels in the ß -cells, cell composition, and insulitis. T1D caused complete or significant loss of ß -cells in all animal models, while increasing numbers of α -cells. Lymphocytic infiltration was noted in and around islets early in the progression of autoimmune diabetes. The loss of lymphocytic infiltration coincided with the absence of ß -cells. In all models, the remaining α - and δ -cells regrouped by relocating to the islet center. The resulting islets were smaller in size and irregularly shaped. Insulin injections subsequent to induction of toxin-induced diabetes significantly preserved ß -cells and islet morphology. Diabetes in animal models is anatomically heterogeneous and involves important changes in numbers and location of the remaining α - and δ -cells. Comparisons with human pancreatic sections from healthy and diabetic donors showed similar morphological changes to the diabetic BBDR rat model.


Assuntos
Diabetes Mellitus Experimental/patologia , Diabetes Mellitus Tipo 1/patologia , Hiperglicemia/patologia , Ilhotas Pancreáticas/patologia , Animais , Glicemia , Diabetes Mellitus Experimental/imunologia , Diabetes Mellitus Experimental/fisiopatologia , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/fisiopatologia , Feminino , Humanos , Hiperglicemia/imunologia , Hiperglicemia/fisiopatologia , Ilhotas Pancreáticas/imunologia , Ilhotas Pancreáticas/fisiopatologia , Masculino , Camundongos , Ratos
9.
Biomed Eng Online ; 11: 79, 2012 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-23095713

RESUMO

BACKGROUND: A one-parameter model was previously proposed to characterize the short axis motion of the LV wall at the mid-ventricle level. The single parameter of this model was associated with the radial contraction of myocardium, but more comprehensive model was needed to account for the rotation at the apex and base levels. The current study developed such model and demonstrated its merits and limitations with examples. MATERIALS AND METHODS: The hearts of five healthy individuals were visualized using cardiac tagged magnetic resonance imaging (tMRI) covering the contraction and relaxation phases. Based on the characteristics of the overall dynamics of the LV wall, its motion was represented by a combination of two components - radial and rotational. Each component was represented by a transformation matrix with a time-dependent variable α or ß.Image preprocessing step and model fitting algorithm were described and applied to estimate the temporal profiles of α and ß within a cardiac cycle at the apex, mid-ventricle and base levels. During this process, the tagged lines of the acquired images served as landmark reference for comparing against the model prediction of the motion. Qualitative and quantitative analyses were performed for testing the performance of the model and thus its validation. RESULTS: The α and ß estimates exhibited similarities in values and temporal trends once they were scaled by the radius of the epicardium (r(epi))and plotted against the time scaled by the period of the cardiac cycle (T(cardiac)) of each heart measured during the data acquisition. α/repi peaked at about Δt/T(cardiac)=0.4 and with values 0.34, 0.4 and 0.3 for the apex, mid-ventricle and base level, respectively. ß/r(epi) similarly maximized in amplitude at about Δt/T(cardiac)=0.4, but read 0.2 for the apex and - 0.08 for the base level. The difference indicated that the apex twisted more than the base. CONCLUSION: It is feasible to empirically model the spatial and temporal evolution of the LV wall motion using a two-parameter formulation in conjunction with tMRI-based visualization of the LV wall in the transverse planes of the apex, mid-ventricle and base. In healthy hearts, the analytical model will potentially allow deriving biomechanical entities, such as strain, strain rate or torsion, which are typically used as diagnostic, prognostic or predictive markers of cardiovascular diseases including diabetes.


Assuntos
Coração/fisiologia , Imageamento por Ressonância Magnética , Modelos Biológicos , Movimento , Função Ventricular , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Reprodutibilidade dos Testes
10.
J Appl Physiol (1985) ; 113(5): 817-26, 2012 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-22797313

RESUMO

One of the fundamental biochemical defects underlying the complications of diabetic cardiovascular system is elevation of diacylglycerol (DAG) and its effects on protein kinase C (PKC) signaling. It has been noted that exercise training attenuates poor cardiac performance in Type 1 diabetes. However, the role of PKC signaling in exercise-induced alleviation of cardiac abnormalities in diabetes is not clear. We investigated the possibility that exercise training modulates PKC-ßII signaling to elicit its beneficial effects on the diabetic heart. bio-breeding diabetic resistant rats, a model reminiscent of Type 1 diabetes in humans, were randomly assigned to four groups: 1) nonexercised nondiabetic (NN); 2) nonexercised diabetic (ND); 3) exercised nondiabetic; and 4) exercised diabetic. Treadmill training was initiated upon the onset of diabetes. At the end of 8 wk, left ventricular (LV) hemodynamic assessment revealed compromised function in ND compared with the NN group. LV myocardial histology revealed increased collagen deposition in ND compared with the NN group, while electron microscopy showed a reduction in the viable mitochondrial fraction. Although the PKC-ßII levels and activity were unchanged in the diabetic heart, the DAG levels were increased. With exercise training, the deterioration of LV structure and function in diabetes was attenuated. Notably, improved cardiac performance in training was associated with a decrease in myocardial DAG levels in diabetes. Exercise-induced benefits on cardiac performance in diabetes may be mediated by prevention of an increase in myocardial DAG levels.


Assuntos
Diabetes Mellitus Tipo 1/metabolismo , Diglicerídeos/antagonistas & inibidores , Diglicerídeos/metabolismo , Miocárdio/metabolismo , Condicionamento Físico Animal/fisiologia , Função Ventricular Esquerda/fisiologia , Sequência de Aminoácidos , Animais , Diglicerídeos/biossíntese , Masculino , Dados de Sequência Molecular , Condicionamento Físico Animal/métodos , Proteína Quinase C/fisiologia , Proteína Quinase C beta , Distribuição Aleatória , Ratos
11.
J Neurochem ; 121(3): 407-17, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22353009

RESUMO

Chronic hyperglycemia could lead to cerebral metabolic alterations and CNS injury. However, findings of metabolic alterations in poorly managed diabetes in humans and animal models are rather inconsistent. We have characterized the cerebral metabolic consequences of untreated hyperglycemia from the onset to the chronic stage in a streptozotocin-induced rat model of diabetes. In vivo ¹H magnetic resonance spectroscopy was used to measure over 20 neurochemicals longitudinally. Upon the onset of hyperglycemia (acute state), increases in brain glucose levels were accompanied by increases in osmolytes and ketone bodies, all of which remained consistently high through the chronic state of over 10 weeks of hyperglycemia. Only after over 4 weeks of hyperglycemia, the levels of other neurochemicals including N-acetylaspartate and glutathione were significantly reduced and these alterations persisted into the chronic stage. However, glucose transport was not altered in chronic hyperglycemia of over 10 weeks. When glucose levels were acutely restored to euglycemia, some neurochemical changes were irreversible, indicating the impact of prolonged uncontrolled hyperglycemia on the CNS. Furthermore, progressive changes in neurochemical levels from control to acute and chronic conditions demonstrated the utility of ¹H magnetic resonance spectroscopy as a non-invasive tool in monitoring the disease progression in diabetes.


Assuntos
Química Encefálica/fisiologia , Diabetes Mellitus Experimental/metabolismo , Hiperglicemia/metabolismo , Doença Aguda , Algoritmos , Animais , Ácido Aspártico/análogos & derivados , Ácido Aspártico/sangue , Transporte Biológico Ativo/fisiologia , Glicemia/metabolismo , Barreira Hematoencefálica/fisiologia , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/metabolismo , Doença Crônica , Diabetes Mellitus Tipo 1/induzido quimicamente , Diabetes Mellitus Tipo 1/metabolismo , Progressão da Doença , Glucose/metabolismo , Glutationa/sangue , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Cinética , Espectroscopia de Ressonância Magnética , Masculino , Ratos , Ratos Sprague-Dawley
12.
Exp Diabetes Res ; 2012: 278620, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22315586

RESUMO

Vascular complications are associated with the progressive severity of diabetes, resulting in significant morbidity and mortality. This study quantifies functional vascular parameters and macrovascular structure in a rat model of type 1 diabetes. While there was no difference in the systemic arterial elastance (Ea) with 50 days of diabetes, changes were noted in the aorta and femoral artery including increased tunica media extracellular matrix content, decreased width of both the media and individual smooth muscle cell layers, and increased incidence of damaged mitochondria. Extracellular matrix proteins and elastin levels were significantly greater in the aorta of diabetic animals. These differences correlated with diminished matrix metalloprotease activity in the aorta of the diabetic animals. In conclusion, diabetes significantly altered the structure and ultrastructure of the aorta and femoral artery before systemic changes in arterial elastance could be detected.


Assuntos
Diabetes Mellitus Experimental/patologia , Diabetes Mellitus Tipo 1/patologia , Angiopatias Diabéticas/patologia , Resistência Vascular , Animais , Aorta/enzimologia , Aorta/patologia , Aorta/fisiopatologia , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/fisiopatologia , Diabetes Mellitus Tipo 1/complicações , Diabetes Mellitus Tipo 1/fisiopatologia , Angiopatias Diabéticas/fisiopatologia , Elastina/análise , Matriz Extracelular/patologia , Proteínas da Matriz Extracelular/análise , Artéria Femoral/patologia , Artéria Femoral/fisiopatologia , Masculino , Metaloproteinases da Matriz/análise , Mitocôndrias Musculares/patologia , Músculo Liso Vascular/patologia , Músculo Liso Vascular/fisiopatologia , Ratos , Ratos Sprague-Dawley , Túnica Média/patologia , Túnica Média/fisiopatologia
13.
Thromb Res ; 129(4): e97-105, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22079445

RESUMO

INTRODUCTION: Plasma serine protease thrombin plays a key role in coagulation, haemostasis and thromboembolic diseases. Direct thrombin inhibitors could be beneficial for future anticoagulant therapy. We have synthesized and studied liporetro-D-peptides - efficient thrombin inhibitors resistant to enzymatic degradation. MATERIALS AND METHODS: Compounds X-D-Arg-D-Phe-OMe, where X=residue of lauric or myristic acid or 9-fluorenylmethoxycarbonyl, have been synthesized by conventional peptide synthesis in solution and their comparative inhibitory analysis in relation to thrombin, factor X, plasmin and trypsin has been conducted. RESULTS: Modification of the synthetic liporetro-D-peptides with the myristic acid residue was the most successful one. This modification has dramatically increased the inhibition efficacy (Ki=0,17 µM) and selectivity toward the chosen target enzyme, thrombin, in comparison to factor X, plasmin and trypsin (more than 600, 900, and 5000-fold, respectively). CONCLUSIONS: Our findings establish an important role of the fatty moiety in the structure of peptide inhibitors with regards to their potency and selectivity toward thrombin.


Assuntos
Antitrombinas/química , Peptídeos/química , Trombina/química , Sítios de Ligação , Ativação Enzimática , Ligação Proteica
14.
Islets ; 3(1): 6-13, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21325888

RESUMO

The existence of morphologically distinct populations of islets in the pancreas was described over 60 years ago. Unfortunately, little attention has been paid to possible functional differences between islet subpopulations until recently. We demonstrated that one population, the small islets, were superior to large islets in a number of functional aspects. However, that work did not determine whether these differences were inherent, or whether they arose because of the challenge of isolation procedures. Nor, were there data to explain the differences in insulin secretion. We utilized immunohistochemistry, immunofluorescence, ELISA, and transmission electron microscopy to compare the unique characteristics found in isolated rat islet populations in situ and after isolation. Insulin secretion of small isolated islets was significantly higher compared to large islets, which correlated with higher insulin content/area in small islets (in situ), a higher density of insulin secretory granules, and greater insulin content/volume in isolated islets. Specifically, the core b-cells of the large islets contained less insulin/cell with a lower insulin granule density than peripheral b-cells. When insulin secretion was normalized for total insulin content, large and small islets released the same percentage of total insulin. Small islets had a higher density of cells/area than large islets in vitro and in situ. The data provide a possible explanation for the inferior insulin secretion from large islets, as they have a lower total cell density and the b-cells of the core contain less insulin/cell.


Assuntos
Insulina/análise , Ilhotas Pancreáticas/química , Ilhotas Pancreáticas/citologia , Animais , Contagem de Células , Separação Celular , Tamanho Celular , Células Cultivadas , Imuno-Histoquímica , Hibridização In Situ , Insulina/metabolismo , Secreção de Insulina , Ilhotas Pancreáticas/metabolismo , Masculino , Concentração Osmolar , Ratos , Ratos Sprague-Dawley , Distribuição Tecidual
15.
Organogenesis ; 6(2): 115-24, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20885858

RESUMO

For people with type 1 diabetes and severe hypoglycemic unawareness, islet transplants offer hope for improving the quality of life. However, islet cell death occurs quickly during or after transplantation, requiring large quantities of islets per transplant. The purpose of this study was to determine whether poor function demonstrated in large islets was a result of diffusion barriers and if removing those barriers could improve function and transplantation outcomes. Islets were isolated from male DA rats and measured for cell viability, islet survival, glucose diffusion and insulin secretion. Modeling of diffusion barriers was completed using dynamic partial differential equations for a sphere. Core cell death occurred in 100% of the large islets (diameter >150 µm), resulting in poor survival within 7 days after isolation. In contrast, small islets (diameter <100 µm) exhibited good survival rates in culture (91%). Glucose diffusion into islets was tracked with 2-NBDG; 4.2 µm/min in small islets and 2.8 µm/min in large islets. 2-NBDG never permeated to the core cells of islets larger than 150 µm diameter. Reducing the diffusion barrier in large islets improved their immediate and long-term viability in culture. However, reduction of the diffusion barrier in large islets failed to improve their inferior in vitro insulin secretion compared to small islets, and did not return glucose control to diabetic animals following transplantation. Thus, diffusion barriers lead to low viability and poor survival for large islets, but are not solely responsible for the inferior insulin secretion or poor transplantation outcomes of large versus small islets.


Assuntos
Insulina/metabolismo , Transplante das Ilhotas Pancreáticas , Ilhotas Pancreáticas/citologia , Ilhotas Pancreáticas/metabolismo , Animais , Morte Celular , Sobrevivência Celular , Difusão , Glucose/metabolismo , Técnicas In Vitro , Secreção de Insulina , Masculino , Modelos Biológicos , Porosidade , Ratos , Coloração e Rotulagem , Resultado do Tratamento
16.
Cardiovasc Diabetol ; 9: 56, 2010 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-20860788

RESUMO

BACKGROUND: Early markers of diabetic autonomic neuropathy (DAN) in an electrocardiogram (ECG) include elevated R wave amplitudes, widening of QTc intervals and decreased heart rate variability (HRV). The severity of DAN has a direct relationship with mortality risk. Aerobic exercise training is a common recommendation for the delay and possible reversal of cardiac dysfunction. Limited research exists on ECG measures for the evaluation of aerobic exercise training in Zucker Diabetic Fatty (ZDF) rat, a model of type 2 diabetes. The objective of this study was to assess whether aerobic exercise training may attenuate diabetes induced ECG changes. METHODS: Male ZDF (obese fa/fa) and control Zucker (lean fa/+) rats were assigned to 4 groups: sedentary control (SC), sedentary diabetic (SD), exercised control (EC) and exercised diabetic (ED). The exercised groups began 7 weeks of treadmill training after the development of diabetes in the ED group. Baseline (prior to the training) and termination measurements included body weight, heart weight, blood glucose and glycated hemoglobin levels and ECG parameters. One way repeated measures ANOVA (group) analyzed within and between subject differences and interactions. Pearson coefficients and descriptive statistics described variable relationships and animal characteristics. RESULTS: Diabetes caused crucial changes in R wave amplitudes (p < 0.001), heart rate variability (p < 0.01), QT intervals (p < 0.001) and QTc intervals (p < 0.001). R wave amplitude augmentation in SD rats from baseline to termination was ameliorated by exercise, resulting in R wave amplitude changes in ED animals similar to control rats. Aerobic exercise training neither attenuated QT or QTc interval prolongation nor restored decreases in HRV in diabetic rats. CONCLUSION: This study revealed alterations in R wave amplitudes, HRV, QT and QTc intervals in ZDF rats. Of these changes, aerobic exercise training was able to correct R wave amplitude changes. In addition, exercise has beneficial effect in this diabetic rat model in regards to ECG correlates of left ventricular mass.


Assuntos
Neuropatias Diabéticas/fisiopatologia , Eletrocardiografia , Cardiopatias/diagnóstico , Cardiopatias/fisiopatologia , Obesidade/fisiopatologia , Condicionamento Físico Animal/fisiologia , Animais , Peso Corporal/fisiologia , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/fisiopatologia , Diabetes Mellitus Tipo 2/terapia , Neuropatias Diabéticas/complicações , Neuropatias Diabéticas/terapia , Modelos Animais de Doenças , Cardiopatias/etiologia , Frequência Cardíaca/fisiologia , Masculino , Obesidade/complicações , Ratos , Ratos Zucker
17.
Cardiovasc Diabetol ; 9: 8, 2010 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-20122173

RESUMO

BACKGROUND: Diminished calcium (Ca2+) transients in response to physiological agonists have been reported in vascular smooth muscle cells (VSMCs) from diabetic animals. However, the mechanism responsible was unclear. METHODOLOGY/PRINCIPAL FINDINGS: VSMCs from autoimmune type 1 Diabetes Resistant Bio-Breeding (DR-BB) rats and streptozotocin-induced rats were examined for levels and distribution of inositol trisphosphate receptors (IP3R) and the SR Ca2+ pumps (SERCA 2 and 3). Generally, a decrease in IP3R levels and dramatic increase in ryanodine receptor (RyR) levels were noted in the aortic samples from diabetic animals. Redistribution of the specific IP3R subtypes was dependent on the rat model. SERCA 2 was redistributed to a peri-nuclear pattern that was more prominent in the DR-BB diabetic rat aorta than the STZ diabetic rat. The free intracellular Ca2+ in freshly dispersed VSMCs from control and diabetic animals was monitored using ratiometric Ca2+ sensitive fluorophores viewed by confocal microscopy. In control VSMCs, basal fluorescence levels were significantly higher in the nucleus relative to the cytoplasm, while in diabetic VSMCs they were essentially the same. Vasopressin induced a predictable increase in free intracellular Ca2+ in the VSMCs from control rats with a prolonged and significantly blunted response in the diabetic VSMCs. A slow rise in free intracellular Ca2+ in response to thapsigargin, a specific blocker of SERCA was seen in the control VSMCs but was significantly delayed and prolonged in cells from diabetic rats. To determine whether the changes were due to the direct effects of hyperglycemica, experiments were repeated using cultured rat aortic smooth muscle cells (A7r5) grown in hyperglycemic and control conditions. In general, they demonstrated the same changes in protein levels and distribution as well as the blunted Ca2+ responses to vasopressin and thapsigargin as noted in the cells from diabetic animals. CONCLUSIONS/SIGNIFICANCE: This work demonstrates that the previously-reported reduced Ca2+ signaling in VSMCs from diabetic animals is related to decreases and/or redistribution in the IP3R Ca2+ channels and SERCA proteins. These changes can be duplicated in culture with high glucose levels.


Assuntos
Cálcio/metabolismo , Diabetes Mellitus Tipo 1/complicações , Diabetes Mellitus Tipo 1/fisiopatologia , Hiperglicemia/metabolismo , Músculo Liso Vascular/enzimologia , Animais , Aorta/metabolismo , Glicemia/metabolismo , Peso Corporal , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/fisiopatologia , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 1/patologia , Hiperglicemia/patologia , Imuno-Histoquímica , Masculino , Ratos , Ratos Endogâmicos BB , Ratos Sprague-Dawley , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/metabolismo
18.
J Clin Med Res ; 2(5): 207-14, 2010 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-21629542

RESUMO

BACKGROUND: Endometrial cancer is one of the most common types of gynecologic cancers. The ability of exercise to reduce the risk of endometrial cancer in women with type 2 diabetes has been established, but no studies have examined this link in type 1 diabetes.A randomized, controlled animal study was designed using a standard rat model of type 1 diabetes. The goal of this study was to investigate the ability of exercise to prevent increased levels of endometrial cancer biomarkers, estrogen receptor (ERα) and p16, and endometrial hyperplasia associated with diabetes. METHODS: FORTY FEMALE RATS WERE RANDOMIZED INTO FOUR GROUPS: sedentary control, exercise control, sedentary or exercised diabetic. Diabetes was induced by alloxan injection. A 4-week treadmill training program was initiated with the development of diabetes. Endometrial tissues were evaluated for hyperplasia and ERα and p16 levels and subcellular localization using microscopy. RESULTS: Severe diabetes lead to hyperplasia in the endometrial tissue in 70% of sedentary diabetic rats. Exercise-trained diabetic rats and the non-diabetic rats displayed no hyperplasia. The expression of ERα increased significantly (p < 0.02) while the expression level of p16 decreased significantly (p < 0.04) in the diabetic sedentary group compared to the non-diabetic groups. Exercise training led to a reversal in the percentage of p16 and ERα positive cells in diabetic rats. CONCLUSIONS: Severe diabetes leads to hyperplasia of the endometrial tissue and increased ERα levels and decreased p16 levels in rats, which can be prevented with aerobic exercise. KEYWORDS: Diabetes; Estrogen receptor alpha; P16; Endometrial hyperplasia; Endometrial cancer; Exercise.

19.
Diabetol Metab Syndr ; 1: 27, 2009 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-20003276

RESUMO

BACKGROUND: The aim of this study was to compare the effects of 10 weeks of resistance or treadmill exercises on glycemic indices levels prior to and immediately following exercise in adults with type 2 diabetes. RESEARCH DESIGN AND METHOD: Twenty inactive subjects (mean age 53.5 years) with type 2 diabetes enrolled in the study. Baseline HbA1c, blood glucose levels, heart rate, and blood pressure were measured for each subject prior to the initiation of the exercise program. Subsequently, subjects were matched to age, waist circumference and sex and assigned to either isocaloric resistance or treadmill exercise groups, which met 3 times per week for 10 weeks. RESULTS: Both groups showed a reduction in pre and post-exercise blood glucose and HbA1c values. There was no change in resting blood pressure or heart rate in either group during the course of the 10 week intervention. The group receiving resistance exercises showed significant differences in the daily pre-exercise plasma glucose readings between the beginning and end of the exercise protocol (p < 0.001). There were significant improvements in the mean HbA1c reading pre and post training in both groups (p < 0.001). However, the greater reduction was noted in the resistance exercise group, and at 10 weeks their HbA1c levels were significantly lower than the group that received treadmill exercises (p < 0.006). CONCLUSION: Ten weeks of resistance exercises were associated with a significantly better glycemic control in adults with type 2 diabetes compared to treadmill exercise.

20.
Biomed Eng Online ; 7: 15, 2008 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-18489766

RESUMO

BACKGROUND: Myocardial motion is an important observable for the assessment of heart condition. Accurate estimates of ventricular (LV) wall motion are required for quantifying myocardial deformation and assessing local tissue function and viability. Harmonic Phase (HARP) analysis was developed for measuring regional LV motion using tagged magnetic resonance imaging (tMRI) data. With current computer-aided postprocessing tools including HARP analysis, large motions experienced by myocardial tissue are, however, often intractable to measure. This paper addresses this issue and provides a solution to make such measurements possible. METHODS: To improve the estimation performance of large cardiac motions while analyzing tMRI data sets, we propose a two-step solution. The first step involves constructing a model to describe average systolic motion of the LV wall within a subject group. The second step involves time-reversal of the model applied as a spatial coordinate transformation to digitally relax the contracted LV wall in the experimental data of a single subject to the beginning of systole. Cardiac tMRI scans were performed on four healthy rats and used for developing the forward LV model. Algorithms were implemented for preprocessing the tMRI data, optimizing the model parameters and performing the HARP analysis. Slices from the midventricular level were then analyzed for all systolic phases. RESULTS: The time-reversal operation derived from the LV model accounted for the bulk portion of the myocardial motion, which was the average motion experienced within the overall subject population. In analyzing the individual tMRI data sets, removing this average with the time-reversal operation left small magnitude residual motion unique to the case. This remaining residual portion of the motion was estimated robustly using the HARP analysis. CONCLUSION: Utilizing a combination of the forward LV model and its time reversal improves the performance of motion estimation in evaluating the cardiac function.


Assuntos
Ventrículos do Coração/anatomia & histologia , Interpretação de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Modelos Cardiovasculares , Movimento/fisiologia , Contração Miocárdica/fisiologia , Função Ventricular , Animais , Simulação por Computador , Masculino , Ratos , Ratos Sprague-Dawley
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