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1.
Braz J Biol ; 83: e275062, 2023.
Article in English | MEDLINE | ID: mdl-38055504

ABSTRACT

Aedes aegypti control is achieved with chemical insecticides that can promote insecticide resistance. In the search for new forms of control, the use of botanical products is currently growing and many tests with oils have already been performed. The plant diversity of Araripe National Forest enables the study of several species against this vector. To evaluate the larvicidal effect of essential oils from plants of this forest, we used field rosemary, copaiba, bay leaf, cashew and pequi. The work was divided into three stages: all oils with the same dosage; the best oil at dosages of 0, 5, 10, 20, 50 and 75 µg/mL; and the best dosage at temperatures of 15, 20, 25, 30 and 35 °C. The oils of field rosemary, copaiba, bay leaf, cashew and pequi were good insecticides when used at dosages above 5 µg/mL. The bay leaf oil showed high larvicidal activity at all dosages tested, showing the highest efficiency at 75 µg/mL. Temperatures of 15 and 35 °C increased the susceptibility of the insect to the effect of the bay leaf oil. The essential oils of field rosemary, copaiba, bay leaf, cashew and pequi, from Araripe National Forest, applied at a dosage of 5µg/mL, showed insecticidal action, although with low efficiency.


Subject(s)
Aedes , Insecticides , Oils, Volatile , Animals , Oils, Volatile/pharmacology , Insecticides/pharmacology , Larva , Mosquito Vectors , Plant Oils/pharmacology
2.
Braz J Med Biol Res ; 54(12): e11499, 2021.
Article in English | MEDLINE | ID: mdl-34878062

ABSTRACT

Bone loss is a potential adverse consequence of rapid and sustained weight loss after bariatric surgery. The aim of the present study was to evaluate the bone mass, body fat distribution, and metabolic parameters in women submitted to Roux-en-Y gastric bypass (RYGB). The study included the following three groups: one group of lean women (control [C] group) and two groups of obese women, one evaluated one year (B1) and the other five years (B5) after RYGB. Dual-energy X-ray absorptiometry and magnetic resonance imaging were used to determine bone mineral density (BMD; lumbar spine, total hip, and femoral neck) and abdominal fat content (subcutaneous [SAT] and visceral [VAT] adipose tissues, and intrahepatic lipids [IHL]). The BMD/body mass index ratio was lower in the B5 compared with the C group at all sites. Serum C-terminal telopeptide of type I collagen (CTX) levels were higher in the B1 and B5 groups compared with the C group. Individuals submitted to RYGB showed greater SAT but similar VAT and IHL values compared with those in the C group. However, the B5 group had higher mean parathyroid hormone levels compared with the other two groups. Individuals submitted to RYGB presented increased levels of CTX and low BMD for body weight than those in the C group, suggesting that bone catabolism is a persistent alteration associated with RYGB. In conclusion, the long-lasting metabolic benefits obtained with RYGB in obesity are counterbalanced by a persistent catabolic effect of the procedure on bone and mineral metabolism.


Subject(s)
Bone Diseases, Metabolic , Gastric Bypass , Obesity, Morbid , Absorptiometry, Photon , Bone Density , Bone and Bones , Female , Gastric Bypass/adverse effects , Humans , Obesity, Morbid/surgery
3.
Braz. j. med. biol. res ; 54(12): e11499, 2021. tab, graf
Article in English | LILACS-Express | LILACS | ID: biblio-1350326

ABSTRACT

Bone loss is a potential adverse consequence of rapid and sustained weight loss after bariatric surgery. The aim of the present study was to evaluate the bone mass, body fat distribution, and metabolic parameters in women submitted to Roux-en-Y gastric bypass (RYGB). The study included the following three groups: one group of lean women (control [C] group) and two groups of obese women, one evaluated one year (B1) and the other five years (B5) after RYGB. Dual-energy X-ray absorptiometry and magnetic resonance imaging were used to determine bone mineral density (BMD; lumbar spine, total hip, and femoral neck) and abdominal fat content (subcutaneous [SAT] and visceral [VAT] adipose tissues, and intrahepatic lipids [IHL]). The BMD/body mass index ratio was lower in the B5 compared with the C group at all sites. Serum C-terminal telopeptide of type I collagen (CTX) levels were higher in the B1 and B5 groups compared with the C group. Individuals submitted to RYGB showed greater SAT but similar VAT and IHL values compared with those in the C group. However, the B5 group had higher mean parathyroid hormone levels compared with the other two groups. Individuals submitted to RYGB presented increased levels of CTX and low BMD for body weight than those in the C group, suggesting that bone catabolism is a persistent alteration associated with RYGB. In conclusion, the long-lasting metabolic benefits obtained with RYGB in obesity are counterbalanced by a persistent catabolic effect of the procedure on bone and mineral metabolism.

4.
Osteoporos Int ; 31(6): 1125-1133, 2020 Jun.
Article in English | MEDLINE | ID: mdl-32108240

ABSTRACT

The present study suggests that insulin resistance has no association with bone quantity, but quality. INTRODUCTION: The literature has contradictory results concerning the influence of insulin resistance on bone. The present study sought to evaluate the association of insulin resistance and adipose tissue with either bone mineral density or the trabecular bone score. METHODS: The study included 56 individuals (36 women and 20 men): age = 46.6 ± 14.2 years, weight = 67.8 ± 10.9 kg, height = 1.65 ± 0.10 m and BMI = 24.8 ± 3.9 kg/m2. The investigational protocol included biochemical determinations and bone assessment by dual X-ray absorptiometry for evaluation of bone mineral density and trabecular bone score. Magnetic resonance was employed to estimate visceral, subcutaneous and bone marrow adipose tissues, as well as intrahepatic lipids. RESULTS: The bone mineral density of the lumbar spine, femoral neck and total hip were not associated with insulin resistance-related parameters [visceral adipose tissue, intrahepatic lipids and homeostatic model assessment of insulin resistance (HOMA-IR)]. In contrast, there was a negative relationship between the trabecular bone score and all these components. The association between the trabecular bone score and HOMA-IR was reinforced after adjustment for age and BMI. Marrow adipose tissue was negatively associated with both bone mineral density and trabecular bone score. CONCLUSIONS: The present study shows that the trabecular bone score is negatively associated with marrow adipose tissue, insulin resistance, visceral adipose tissue and intrahepatic lipid measurements. Additionally, there was a negative relationship between saturated lipids in marrow adipose tissue and the trabecular bone score. These results encourage further studies to investigate the role of the trabecular bone score exam in the clinical evaluation of osteoporosis in conditions of insulin resistance.


Subject(s)
Adipose Tissue/diagnostic imaging , Bone Density , Cancellous Bone/diagnostic imaging , Insulin Resistance , Absorptiometry, Photon , Adult , Bone Marrow , Female , Humans , Intra-Abdominal Fat , Lipids/analysis , Liver/chemistry , Magnetic Resonance Imaging , Male , Middle Aged
5.
Allergol Immunopathol (Madr) ; 47(5): 417-424, 2019.
Article in English | MEDLINE | ID: mdl-31235184

ABSTRACT

INTRODUCTION: The association regarding the atopic sensitization to mite aeroallergens and the socio-environmental features is still inconsistent. OBJECTIVES: We analyzed the role played by socioeconomic and environmental factors in the prevalence of sensitization to house dust mite (HDM) allergens, and associated with the risk of developing asthma symptoms. PATIENTS AND METHODS: This is a case-control study conducted with 108 patients, aged 1-17. We inquired about family habits, socioeconomic and environmental features. We applied the International Study of Asthma and Allergies in Childhood questionnaire. RESULTS: We observed patients sensitized to all HDM tested, Derp (42%), Derf (37%) and Blot (33%). Middle family income (OR: 2.74; CI95%: 1.127-6.684), exposure to dog (OR: 3.758, CI95%: 1.127-6.684) and artificial climatization (OR: 4.319, CI95%: 1.398-13.348) were associated with sensitization to Derp. We also observed protective factors, such as sharing of dormitories, washing cycle for bedspreads and the presence of basic sanitation. An increased risk of sensitization to Derf was associated with Blot sensitization (OR: 3.172, CI95%: 1.083-9.292) and presence of mold on the walls (OR: 3.095, CI95%: 1.063-9.008). A protective factor was dormitory sharing. For sensitization to Blot, we observed an increase in the risk associated with Derp sensitization (OR: 3.462, CI95%: 1.191-10.061) and exposure to dog (OR: 3.255, CI95%: 0.987-10.736). In addition, sensitization to Blot increases the risk of developing asthma symptoms (OR: 2.732, CI95%: 0.981-7.606). CONCLUSION: Our data show distinct sociodemographic and environmental relations that lead to HDM sensitization and increased probability of development of allergic diseases.


Subject(s)
Asthma/epidemiology , Environmental Exposure/adverse effects , Hypersensitivity/epidemiology , Socioeconomic Factors , Adolescent , Animals , Antigens, Dermatophagoides/immunology , Brazil/epidemiology , Case-Control Studies , Child , Child, Preschool , Dust , Female , Humans , Infant , Male , Prevalence , Pyroglyphidae/immunology
6.
J Periodontol ; 89(11): 1351-1361, 2018 11.
Article in English | MEDLINE | ID: mdl-29797719

ABSTRACT

BACKGROUND: Growth hormone (GH) has been identified as an important regulator of the immune response. We have previously shown that adults with isolated GH deficiency (IGHD) due to a mutation in the GH releasing hormone receptor (GHRHR) gene, have a greater chance of having periodontitis. However, the interaction of GH with periodontal tissues is still unknown, and this population has emerged as a unique model to investigate this issue. Therefore, we evaluated the microbiological and immunological periodontal profiles of such individuals. METHODS: Nineteen IGHD and 19 controls matched by age, sex, diabetes, and smoking status, were enrolled in this case-control study. Periodontal clinical parameters (probing depth [PD] and clinical attachment loss [AL]) were measured at six sites per tooth. Immune mediators (C-reactive protein, matrix metalloproteinase [MMP]-8, MMP-9, interleukin [IL]-1α, IL-6, IL-8, tumor necrosis factor [TNF]-α, adiponectin, and leptin) were analyzed by enzyme-linked immunosorbent assay (ELISA) in the gingival crevicular fluid (GCF) in four non-adjacent sites for each participant (two with PD ≤3 mm [shallow sites] and two with PD ≥7 mm or the worst PD found in the mouth [deep sites]). Bacterial quantification (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia) of subgingival biofilm samples collected from these same sites was performed by quantitative real-time polymerase chain reaction (qPCR). RESULTS: IGHD individuals presented higher values of PD and AL, and increased levels of CRP, IL-8, MMP-8, and adiponectin in the GCF. Bacterial quantification did not identify differences between the two groups. CONCLUSION: IGHD alters the local immune response in periodontal pockets leading to greater attachment loss, and GH stands out as an important hormone to be evaluated in the pathogenesis of periodontitis.


Subject(s)
Dental Plaque , Dwarfism, Pituitary , Adult , Case-Control Studies , Gingival Crevicular Fluid , Humans , Periodontal Attachment Loss , Periodontal Pocket , Porphyromonas gingivalis
7.
Zoonoses Public Health ; 65(4): 395-403, 2018 06.
Article in English | MEDLINE | ID: mdl-29424092

ABSTRACT

Animal bites are a serious public health issue, and prevention strategies have been consistently documented worldwide. The aim of this study was to characterize human anti-rabies treatment in 11 counties of the Salgado microregion, Pará state, Brazil, which borders the Bragantina microregion, where exposures of human rabies were reported in 2004 and 2005. A descriptive retrospective study was conducted using anti-rabies treatment notifications registered in the Information System for Notifiable Diseases (SINAN) database of the State Department of Public Health of Pará (SESPA) from January 2000 to December 2014. In this period, 13,403 exposures were reported, with a growing annual trend (Y = 68.571x + 344.96). The years 2012 and 2013 presented the highest exposure incidence. Salinópolis was the county with the highest average annual incidence per 10,000 persons (62.83), followed by São João de Pirabas (43.28) and São Caetano de Odivelas (41.27). Most patients were males (59.6%) and were 1-19 years old (48.7%). The main species involved in aggressions were dogs (74.1%), followed by bats (13.1%) and cats (7.4%). Biting was the most common kind of exposure, mostly on the lower limbs (39.6%). This study shows that aggression by bats was the second most common cause of demand for the service in the region for the past 14 years. The low quality of records may increase the difficulty of rabies surveillance in Pará.


Subject(s)
Bites and Stings/veterinary , Epidemiological Monitoring , Post-Exposure Prophylaxis/statistics & numerical data , Rabies/epidemiology , Rabies/prevention & control , Adolescent , Adult , Aged , Animals , Brazil/epidemiology , Cats , Child , Child, Preschool , Chiroptera/virology , Dogs , Female , Humans , Incidence , Infant , Male , Middle Aged , Post-Exposure Prophylaxis/methods , Public Health/methods , Public Health/statistics & numerical data , Rabies/transmission , Rabies/virology , Rabies Vaccines/administration & dosage , Retrospective Studies , Vaccination Coverage/statistics & numerical data , Young Adult
8.
Osteoporos Int ; 28(7): 2167-2176, 2017 07.
Article in English | MEDLINE | ID: mdl-28405731

ABSTRACT

Bone marrow adipose tissue has not been studied in patients with inactive inflammatory bowel disease. We found that these patients have preserved marrow adiposity even with low bone mass. Factors involved in bone loss in active disease may have long-lasting effects but do not seem to affect bone marrow adiposity. INTRODUCTION: Reduced bone mass is known to occur at varying prevalence in patients with inflammatory bowel diseases (IBD) because of inflammation, malnutrition, and steroid therapy. Osteoporosis may develop in these patients as the result of an imbalanced relationship between osteoblasts and adipocytes in bone marrow. This study aimed to evaluate for the first time bone mass and bone marrow adipose tissue (BMAT) in a particular subgroup of IBD patients characterized by long-term, steroid-free remission. METHODS: Patients with Crohn's disease (CD; N = 21) and ulcerative colitis (UC; N = 15) and controls (C; N = 65) underwent dual X-ray energy absorptiometry and nuclear magnetic resonance spectroscopy of the L3 lumbar vertebra for BMAT assessment. RESULTS: Both the CD and UC subgroups showed significantly higher proportions of patients than controls with Z-score ≤-2.0 at L1-L4 (C 1.54%; CD 19.05%; UC 20%; p = 0.02), but not at other sites. The proportions of CD patients with a T-score ˂-1.0 at the femoral neck (C 18.46%; CD 47.62%; p = 0.02) and total hip (C 16.92%; CD 42.86%; p = 0.03) were significantly higher than among controls. There were no statistically significant differences between IBD patients and controls regarding BMAT at L3 (C 28.62 ± 8.15%; CD 29.81 ± 6.90%; UC 27.35 ± 9.80%; p = 0.67). CONCLUSIONS: IBD patients in long-term, steroid-free remission may have a low bone mass in spite of preserved BMAT. These findings confirm the heterogeneity of bone disorders in IBD and may indicate that factors involved in bone loss in active disease may have long-lasting effects on these patients.


Subject(s)
Adipose Tissue/pathology , Bone Marrow/pathology , Inflammatory Bowel Diseases/complications , Osteoporosis/etiology , Absorptiometry, Photon/methods , Adult , Bone Density/physiology , Case-Control Studies , Colitis, Ulcerative/complications , Colitis, Ulcerative/pathology , Colitis, Ulcerative/physiopathology , Crohn Disease/complications , Crohn Disease/pathology , Crohn Disease/physiopathology , Female , Femur Neck/physiopathology , Hip Joint/physiopathology , Humans , Inflammatory Bowel Diseases/pathology , Inflammatory Bowel Diseases/physiopathology , Lumbar Vertebrae/physiopathology , Magnetic Resonance Imaging/methods , Male , Middle Aged , Osteoporosis/pathology , Osteoporosis/physiopathology , Young Adult
9.
Br J Pharmacol ; 172(6): 1468-78, 2015 Mar.
Article in English | MEDLINE | ID: mdl-24962517

ABSTRACT

Nitric oxide (NO) has long been recognized as a multifaceted participant in brain physiology. Despite the knowledge that was gathered over many years regarding the contribution of NO to neuronal plasticity, for example the ability of the brain to change in response to new stimuli, only in recent years have we begun to understand how NO acts on the molecular and cellular level to orchestrate such important phenomena as synaptic plasticity (modification of the strength of existing synapses) or the formation of new synapses (synaptogenesis) and new neurons (neurogenesis). Post-translational modification of proteins by NO derivatives or reactive nitrogen species is a non-classical mechanism for signalling by NO. S-nitrosation is a reversible post-translational modification of thiol groups (mainly on cysteines) that may result in a change of function of the modified protein. S-nitrosation of key target proteins has emerged as a main regulatory mechanism by which NO can influence several levels of brain plasticity, which are reviewed in this work. Understanding how S-nitrosation contributes to neural plasticity can help us to better understand the physiology of these processes, and to better address pathological changes in plasticity that are involved in the pathophysiology of several neurological diseases.


Subject(s)
Neuronal Plasticity/physiology , Nitric Oxide/metabolism , Protein Processing, Post-Translational/physiology , Animals , Humans , Nervous System Diseases/physiopathology , Nitrosation/physiology , Reactive Nitrogen Species/metabolism
10.
Gait Posture ; 40(1): 1-10, 2014.
Article in English | MEDLINE | ID: mdl-24674637

ABSTRACT

The aim of the present review was to examine the experimental, case-control studies that investigated the effect of light touch on postural sway in individuals with balance problems due to aging, brain lesion or other motor or sensory deficits. Articles published before the end of March of 2013 were searched in PubMed, Scielo and Lilacs databases using terms related to postural control and sensory information. Twelve studies that assessed the postural sway of individuals with balance problems during quiet standing with the light touch using a force plate were reviewed. Two reviewers rated all selected articles as having good quality. The effect of light touch on postural control was reported by all eligible studies regardless of the cause of the balance problem of the participants. Such effect was more evident when the applied vertical force was greater than 1N, but if individuals with poor balance took more advantage of the light touch than healthy ones it depended on the source of their balance problems and not the amount of the applied force. These findings suggested that the maintenance of the fingertip lightly touching an external surface could provide additional somatosensory information for individuals with poor balance and then it could be used as a strategy to improve the control of upright standing during intervention programs.


Subject(s)
Aging/physiology , Feedback, Sensory/physiology , Postural Balance/physiology , Sensation Disorders/physiopathology , Touch/physiology , Adult , Aged , Humans , Middle Aged , Movement/physiology , Reference Values , Young Adult
11.
Neurosci Lett ; 513(1): 6-11, 2012 Mar 28.
Article in English | MEDLINE | ID: mdl-22342925

ABSTRACT

The present study aimed to investigate whether stroke survivals are able to use the additional somatosensory information provided by the light touch to reduce their postural sway during the upright stance. Eight individuals, naturally right-handed pre-stroke, and eight healthy age-matched adults stood as quiet as possible on a force plate during 35s. Participants performed two trials for each visual condition (eyes open and closed) and somatosensory condition (with and without the right or left index fingertip touching an instrumented rigid and fixed bar). When participants touched the bar, they were asked to apply less than 1N of vertical force. The postural sway was assessed by the center of pressure (COP) displacement area, mean amplitude and velocity. In addition, the mean and standard deviation of the force vertically applied on the bar during the trials with touch were assessed. The averaged values of COP area, amplitude and velocity were greater for stroke individuals compared to healthy adults during all visual and somatosensory conditions. For both groups, the values of all variables increased when participants stood with eyes closed and reduced when they touched the bar regardless of the side of the touch. Overall, the results suggested that, as healthy individuals, persons with post-stroke hemiparesis are able to use the additional somatosensory information provided by the light touch to reduce the postural sway.


Subject(s)
Paresis/etiology , Paresis/rehabilitation , Posture/physiology , Stroke/complications , Touch/physiology , Aged , Analysis of Variance , Chronic Disease , Evoked Potentials, Somatosensory/physiology , Evoked Potentials, Visual/physiology , Female , Functional Laterality/physiology , Humans , Male , Middle Aged , Photic Stimulation , Physical Stimulation
12.
Mater Sci Eng C Mater Biol Appl ; 32(6): 1588-93, 2012 Aug 01.
Article in English | MEDLINE | ID: mdl-24364964

ABSTRACT

The search for bioactive molecules to be employed as recognition elements in biosensors has stimulated researchers to pore over the rich Brazilian biodiversity. In this sense, we introduce the use of natural cashew gum (Anacardium occidentale L.) as an active biomaterial to be used in the form of layer-by-layer films, in conjunction with phthalocyanines, which were tested as electrochemical sensors for dopamine detection. We investigated the effects of chemical composition of cashew gum from two different regions of Brazil (Piauí and Ceará states) on the physico-chemical characteristics of these nanostructures. The morphology of the nanostructures containing cashew gum was studied by atomic force microscopy which indicates that smooth films punctuated by globular features were formed that showed low roughness values. The results indicate that, independent of the origin, cashew gum stands out as an excellent film forming material with potential application in nanobiomedical devices as electrochemical sensors.


Subject(s)
Anacardium/chemistry , Biocompatible Materials/chemistry , Nanostructures/chemistry , Biosensing Techniques/methods , Dopamine/chemistry , Indoles/chemistry , Isoindoles
13.
Arq. bras. med. vet. zootec ; 63(5): 1099-1103, out. 2011. tab
Article in Portuguese | LILACS | ID: lil-605834

ABSTRACT

Foram avaliadas as técnicas radiográficas dentárias intra (TIB) e extrabucal (TEB) em 50 cães com doença periodontal, no intuito de padronizar os procedimentos de diagnóstico dessa síndrome. A TIB revelou que 16 animais não apresentaram lesões ósseas visíveis, enquanto a TEB apontou que 39 pacientes foram negativos para as mesmas lesões. Em resumo, a TIB foi mais eficaz na detecção de sinais radiográficos, especialmente as chamadas lesões finas, que a TEB, sendo a técnica de escolha na síndrome periodontal.


The intra (IOT) and extraoral (EOT) dental radiographic techniques in 50 dogs with periodontal disease were compared to standardize the most appropriate procedure for accurate diagnosis of abnormalities that occur in this syndrome. For IOT, 16 animals showed no visible radiographic lesions, whereas in EOT, 39 patients were negative for the same radiographic lesions. For incisor and canine teeth, IOT presented the highest sensitivity of lesion detection, while there was no significant difference for the premolar and molar teeth group. It is concluded that IOT is more effective in detecting radiographic signs (especially the so-called thin lesions) than the EOT and should therefore be the technique of choice in the periodontal syndrome.


Subject(s)
Animals , Dogs , Dogs/physiology , Periodontal Diseases/diagnosis , Periodontal Diseases/veterinary , Radiography, Dental/methods , Radiography, Dental/veterinary , Dentistry/veterinary , Periodontics/methods
14.
Cell Death Differ ; 14(9): 1635-46, 2007 Sep.
Article in English | MEDLINE | ID: mdl-17585341

ABSTRACT

Proteolytic cleavage of the Na(+)/Ca(2+) exchanger (NCX) by calpains impairs calcium homeostasis, leading to a delayed calcium overload and excitotoxic cell death. However, it is not known whether reversal of the exchanger contributes to activate calpains and trigger neuronal death. We investigated the role of the reversal of the NCX in Ca(2+) dynamics, calpain activation and cell viability, in alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA) receptor-stimulated hippocampal neurons. Selective overactivation of AMPA receptors caused the reversal of the NCX, which accounted for approximately 30% of the rise in intracellular free calcium concentration ([Ca(2+)](i)). The NCX reverse-mode inhibitor, 2-[2-[4-(4-nitrobenzyloxy)phenyl]ethyl]isothiourea (KB-R7943), partially inhibited the initial increase in [Ca(2+)](i), and prevented a delayed increase in [Ca(2+)](i). In parallel, overactivation of AMPA receptors strongly activated calpains and led to the proteolysis of NCX3. KB-R7943 prevented calpain activation, cleavage of NCX3 and was neuroprotective. Silencing of NCX3 reduced Ca(2+) uptake, calpain activation and was neuroprotective. Our data show for the first time that NCX reversal is an early event following AMPA receptor stimulation and is linked to the activation of calpains. Since calpain activation subsequently inactivates NCX, causing a secondary Ca(2+) entry, NCX may be viewed as a new suicide substrate operating in a Ca(2+)-dependent loop that triggers cell death and as a target for neuroprotection.


Subject(s)
Calcium/metabolism , Calpain/metabolism , Hippocampus/cytology , Neurons/metabolism , Receptors, AMPA/metabolism , Sodium-Calcium Exchanger/metabolism , Animals , Cells, Cultured/cytology , Cells, Cultured/metabolism , Gene Silencing , Homeostasis , Nerve Degeneration , Neurons/cytology , Rats , Sodium-Calcium Exchanger/antagonists & inhibitors , Sodium-Calcium Exchanger/genetics , Thiourea/analogs & derivatives , Thiourea/pharmacology
15.
Brain Res Bull ; 69(3): 306-10, 2006 Apr 14.
Article in English | MEDLINE | ID: mdl-16564426

ABSTRACT

Huntington's disease (HD) is a hereditary neurodegenerative disorder caused by a CAG repeat expansion in the HD gene. Excitotoxic cell damage by excessive stimulation of glutamate receptors has been hypothesized to contribute to the pathogenesis of HD. Transgenic mouse models of HD have shown variable sensitivity to excitotoxicity. The models differ in the genetic background, the type and length of the promoter driving the transgene expression, the CAG repeat length and/or the HD gene construct length. Furthermore, one has to differentiate whether transgenic or knock-in models have been used. All these factors may be involved in determining the responsiveness to an excitotoxic insult. Here, we explored the responsiveness to excitotoxic damage using a transgenic HD rat model carrying 22% of the rat HD gene which is driven by the rat HD promoter and which harbors 51 CAG repeats. 3 and 18 months old transgenic HD rats and their wild-type littermates received unilateral intrastriatal injections of the glutamate analogue quinolinic acid. Lesion size was assessed 7 days later using the degenerative stain Fluoro-Jade and by immunohistochemistry for the neuronal protein NeuN. No difference in susceptibility to excitotoxicity was found between the groups. Our study supports mouse data showing maintained susceptibility to excitotoxicity with the expression of around 25% of the full HD gene. Differences in sensitivity to excitotoxicity between genetic animal models of HD may be dependent on the length of the expressed HD gene although additional factors are also likely to be important.


Subject(s)
Huntington Disease/genetics , Huntington Disease/physiopathology , Neurons/metabolism , Trinucleotide Repeat Expansion/genetics , Analysis of Variance , Animals , Animals, Genetically Modified , Brain/drug effects , Brain/pathology , Brain/physiopathology , Disease Models, Animal , Fluoresceins , Huntington Disease/pathology , Immunohistochemistry/methods , Neurons/drug effects , Neurotoxins/pharmacology , Organic Chemicals , Phosphopyruvate Hydratase/metabolism , Quinolinic Acid/pharmacology , Rats , Time Factors
16.
Rev. Hosp. Clin. Fac. Med. Univ. Säo Paulo ; 46(2): 51-8, mar.-abr. 1991. tab
Article in Portuguese | LILACS | ID: lil-108318

ABSTRACT

O objetivo do presente trabalho foi estudar o papel desempenhado pelo rim na retencao de sodio e agua na insuficiencia cardiaca em caes com fistulas arterio-venosas femorais atraves de medidas de clearance e hemodinamica. Vinte e sete caes foram estudados em hidropenia e em diurese aquosa, 96 horas apos a realizacao de fistulas arterio-venosas femorais bilaterais, em 3 periodos: 1) fistulas abertas; 2) fistulas fechadas e 3) fistulas reabertas. Os animais retinham sal e agua e desenvolveram edema no periodo em que as fistulas estavam abertas. Quando as mesmas foram fechadas ocorreu uma maior diurese, natriurese, com aumento da excrecao urinaria de fosfato e do aporte distal de solutos, sugerindo uma diminuicao da reabsorcao proximal de sodio e agua. Apos a reabertura das fistulas, observou-se um aumento da reabsorcao de sodio pelos segmentos distais do nefron, sugerido pela elevacao da excrecao de agua livre por unidade de aporte de solutos. Estes achados nao foram acompanhados por alteracoes da distribuicao do fluxo sanguineo renal cortical. Em conclusao, a retencao de sodio e agua na insuficiencia cardiaca congestiva produzida por fistulas arterio-venosas se deve a um aumento da reabsorcao de sodio pelos segmentos distais do nefron e nao e devida a uma redistribuicao do fluxo sanguineo renal cortical.


Subject(s)
Male , Animals , Dogs , Heart Failure/physiopathology , Kidney Tubules/physiology , Arteriovenous Fistula , Disease Models, Animal , Edema , Heart Failure/urine , Hemodynamics , Kidney/physiology , Sodium/urine
17.
Article in Portuguese | MEDLINE | ID: mdl-1843368

ABSTRACT

This study was designed to evaluate the role of the kidney on sodium retention in congestive heart failure by clearance and hemodynamic studies. Twenty seven dogs were studied during hydropenia and aqueous diuresis 96 hours after the construction of a bilateral femoral A-V fistula, in 3 periods: 1) with open fistulae; 2) with closed fistulae and 3) with reopened fistulae. The animals retained sodium and water and developed edema during the first period when the fistulae were opened. Closure of the AV fistulae produced an enhanced diuresis and natriuresis associated with an increase in phosphaturia and distal sodium delivery, suggesting a diminished proximal sodium reabsorption. However, when the fistulae were reopened, sodium retention was observed in the presence of an increase in free-water clearance corrected by distal sodium delivery, indicating an increase in sodium reabsorption by distal segments. These findings were not associated with alterations in cortical distribution of renal blood flow. In conclusion, the sodium and water retention in congestive heart failure produced by A-V fistula is due to an increase in sodium reabsorption by the distal nephron segments, and it is not associated to a redistribution of the cortical renal blood flow.


Subject(s)
Heart Failure/metabolism , Kidney Tubules/metabolism , Kidney/metabolism , Sodium/metabolism , Animals , Arteriovenous Fistula , Disease Models, Animal , Diuresis , Dogs , Edema/etiology , Heart Failure/physiopathology , Hemodynamics , Male
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