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In Brazil, the circulation of hepatitis E virus (HEV) has been demonstrated in distinct groups of individuals and some animals, but its prevalence among individuals with human immunodeficiency virus (HIV) infection is unknown. This study aimed to assess the frequency of serological and molecular HEV markers in individuals infected with HIV from São Paulo, Brazil. Serum and plasma samples of 354 HIV-infected patients collected between 2007 and 2013 were included. All samples were tested for anti-HEV IgG and IgM antibodies and HEV RNA. Anti-HEV IgG and IgM antibodies were detected in 10.7% (38/354) and 1.4% (5/354) of the samples, respectively. Both antibodies were detected simultaneously in only two samples. HEV RNA was not detected in any sample. There was no significant correlation of anti-HEV serological status (positivity to anti-HEV IgG and/or IgM) with sex, age, CD4+ T cell count, HIV viral load, antiretroviral therapy, liver enzyme levels, or coinfection with hepatitis B virus and/or hepatitis C virus. Our study provides serological evidence of past and recent HEV infections in HIV-infected patients from São Paulo, Brazil. However, the occurrence of ongoing HEV infection appears be a rare event in this population.
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Coinfecção/virologia , Infecções por HIV/complicações , Infecções por HIV/virologia , Hepatite E/complicações , Hepatite E/virologia , Adulto , Idoso , Biomarcadores , Brasil/epidemiologia , Coinfecção/epidemiologia , Feminino , Infecções por HIV/epidemiologia , Hepatite E/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Testes Sorológicos , Carga ViralRESUMO
Plant-based analogs have been developed to mimic foods from animal sources by using ingredients from vegetable sources. Among the strategies to produce plant-based structures is the gelation of mixtures between plant proteins and polysaccharides. In this study, our aim was to investigate gels of pea proteins and gellan gum with high protein concentration and the addition of salt (potassium and sodium chloride). In the first step, a qualitative mapping was performed to select pea protein and gellan gum concentrations to produce self-sustainable gels. After that, the effect of salt addition was investigated for the formulations containing 10-15 % (wt) pea protein and 0.5-1 % (wt) gellan gum. The results showed that the gels containing potassium ions were more rigid and less deformable, with lesser water loss by syneresis. The morphological analysis showed a spatial exclusion of pea protein from the gel network mainly structured by the gellan gum. While potassium ions led to a more compact network, calcium ions promoted higher pores in the structure. Depending on the composition, the mechanical properties of gels were similar to some products from animal sources. So, the information obtained from these gels can be applied to the structuring of formulations in the development of plant-based analogs.
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Proteínas de Ervilha , Animais , Polissacarídeos Bacterianos/química , Géis/química , Íons , Potássio/químicaRESUMO
BACKGROUND: Among marginal zone lymphomas (MZLs), bone marrow (BM) involvement features are well established in the splenic marginal zone lymphoma (SMZL); few data are available for extranodal marginal zone lymphoma (EMZL) and nodal marginal zone lymphoma (NMZL). PATIENTS AND METHODS: Incidence and patterns of histologic BM involvement are studied in 120 MZL patients (48 SMZL, 59 EMZL, 13 NMZL) at onset and during follow-up; relationships between clinical features, BM histology and flow cytometry (FC) are analyzed. RESULTS: At diagnosis, BM involvement occurs in 90% SMZL, 22% EMZL and 54% NMZL (P<0.0001); at reevaluation, incidence raises to 96% in SMZL and 34% in EMZL. Concordance between histology and FC is found in 87% of cases; most discordant cases have positive histology but negative FC. SMZL and EMZL show a nodular BM infiltration; the interstitial pattern is frequent in NMZL (P<0.0001); sinusoidal localization is typical of SMZL, frequent in NMZL and occasional in EMZL (P=0.0001). Stage, leukemic disease, B symptoms, more than one extranodal involved site, splenomegaly, elevated beta2-microglobulin, serum monoclonal component, International Prognostic Index (IPI) and age-adjusted IPI are directly related to BM infiltration. CONCLUSIONS: The different prevalence of BM involvement in MZL subtypes reflects their heterogeneous dissemination modalities; histology seems more sensible than FC to detect BM infiltration; development of BM involvement during follow-up is typical of EMZL.
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Neoplasias da Medula Óssea/epidemiologia , Neoplasias da Medula Óssea/secundário , Medula Óssea/patologia , Linfoma de Zona Marginal Tipo Células B/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Medula Óssea/patologia , Progressão da Doença , Feminino , Citometria de Fluxo , Seguimentos , Humanos , Incidência , Linfoma de Zona Marginal Tipo Células B/diagnóstico , Linfoma de Zona Marginal Tipo Células B/epidemiologia , Masculino , Pessoa de Meia-Idade , Estudos RetrospectivosRESUMO
OBJECTIVES: Tuberculosis (TB) remains an important disease associated with HIV infection and AIDS in Brazil, even in a setting of free access to antiretroviral therapy (ART) and TB treatment. In previous studies, isoniazid therapy (IT) for latent infection with Mycobacterium tuberculosis (LIMTb) was found to reduce the risk of TB by 62% in patients with a tuberculin test (TT)>5 mm. The objectives of this study were to investigate the occurrence of TB, the prevalence of LIMTb and the coverage of the TT and IT, and to estimate the number of missed opportunities to prevent TB in patients with HIV/AIDS. METHODS: A random sample of patients with HIV/AIDS was selected; data from the medical files were obtained, and a TT was performed in consenting subjects. RESULTS: In the 203 subjects included in the study, TB occurrence was 13.3%, LIMTb prevalence was 20% and the coverage of the TT and IT was 59.2 and 55%, respectively. Patients with TB had a lower nadir CD4 cell count, but their CD4 recovery was comparable to that of non-TB patients. Patients with LIMTb always had a higher CD4 cell count. CONCLUSIONS: By expanding the coverage of the TT and IT to nearly 100%, we could more than double the number of prevented cases of TB. TB prevention programmes must be reinforced to reduce the number of missed opportunities for diagnosis, and IT must be improved to reduce TB among patients with HIV/AIDS. Empowering patients with knowledge about TB, the preventive role of IT and the need for an annual TT may be the best way of lowing rates of TB in patients with HIV/AIDS.
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Infecções por HIV/epidemiologia , Tuberculose Latente/epidemiologia , Tuberculose/epidemiologia , Adulto , Idoso , Antirretrovirais/uso terapêutico , Terapia Antirretroviral de Alta Atividade , Antituberculosos/uso terapêutico , Brasil/epidemiologia , Contagem de Linfócito CD4 , Estudos Transversais , Feminino , Infecções por HIV/tratamento farmacológico , Infecções por HIV/transmissão , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Isoniazida/uso terapêutico , Tuberculose Latente/tratamento farmacológico , Masculino , Programas de Rastreamento/estatística & dados numéricos , Pessoa de Meia-Idade , Mycobacterium tuberculosis , Prevalência , Distribuição por Sexo , Comportamento Sexual , Teste Tuberculínico/estatística & dados numéricos , Tuberculose/prevenção & controle , Adulto JovemRESUMO
Since ionic Ca2+ binds with intracellular calmodulin (CaM) before activating proteases, kinases, and phospholipases, demonstration of persistent Ca2+-CaM binding in neurons destined to show ischemic cellular injury would support the concept that elevated intracellular Ca2+ plays a causative role in ischemic neuronal damage. In order to characterize Ca2+-CaM binding, we used a sheep anti-CaM antibody (CaM-Ab) which recognizes CaM that is not bound to Ca2+ or brain target proteins. Therefore, immunohistochemical staining of brain sections by labeled CaM-Ab represented only unbound CaM. Six normal rats were compared to 15 animals rendered ischemic for 30 min by a modification of the four-vessel occlusion model. Animals were killed immediately after ischemia, and after 2 and 24 h of reperfusion. Brain sections through hippocampus were incubated in CaM-Ab, and a diaminobenzadiene labeled anti-sheep secondary antibody was added to stain the CaM-Ab. Staining in the endal limb of dentate, dorsal CA1, lateral CA3, and parietal cortex was graded on a 4-point scale. All normal animals had grade 4 staining indicating the presence of unbound CaM in all four brain regions. Ischemic animals demonstrated reduced (grade 0 to 2) staining in the CA1 and CA3 regions immediately and 2 and 24 h after ischemia (p less than 0.01 for both regions at all three time intervals) indicating persistent binding of CaM with Ca2+ and target proteins in these regions. Staining decreased in dentate and cortex up to 2 h after ischemia (p = 0.02 for both regions) but returned toward normal by 24 h.(ABSTRACT TRUNCATED AT 250 WORDS)
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Cálcio/metabolismo , Calmodulina/metabolismo , Ataque Isquêmico Transitório/metabolismo , Neurônios/metabolismo , Animais , Calmodulina/isolamento & purificação , Ácido Egtázico/farmacologia , Ataque Isquêmico Transitório/patologia , Masculino , Peso Molecular , Neurônios/patologia , Ligação Proteica , Ratos , Ratos Endogâmicos , Valores de ReferênciaRESUMO
We followed 19 men and 19 women with asymptomatic carotid stenosis up to 30 months to determine whether hematologic or lipid abnormalities could identify those individuals developing progressing carotid atherosclerosis (defined as an increase in mean percent stenosis greater than or equal to 19% or an increase in a single region of greater than or equal to 23%) on B-mode carotid ultrasonography performed at 2- to 6-month intervals. Our patients demonstrated increased beta-thromboglobulin, platelet factor 4, and fibrinogen compared with age-matched controls. Eight patients developed progression of carotid stenosis, and this group had higher baseline low-density lipoprotein (LDL) and fibrinogen than the 30 nonprogressing patients. Multiple regression analyses of age, sex, smoking, coronary artery disease, peripheral vascular disease, diabetes, hypertension, and baseline high-density lipoprotein (HDL), HDL2, HDL3, LDL, beta-thromboglobulin, platelet factor 4, and fibrinogen identified coronary artery disease and elevated LDL and fibrinogen as the only independent variables significantly associated with the progressing group. We conclude that, in patients with carotid atherosclerosis, a combination of coronary artery disease and elevated LDL and fibrinogen will predict with 88% accuracy whether the patient will have progressing carotid stenosis.
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Doenças das Artérias Carótidas/fisiopatologia , Lipídeos/sangue , Idoso , Idoso de 80 Anos ou mais , Artérias Carótidas/patologia , Doenças das Artérias Carótidas/sangue , Doenças das Artérias Carótidas/diagnóstico , Constrição Patológica , Análise Discriminante , Feminino , Previsões , Humanos , Masculino , Pessoa de Meia-Idade , UltrassonografiaRESUMO
To evaluate the safety and efficacy of delapril versus enalapril in patients with congestive heart failure (CHF), New York Heart Association (NYHA) class II and III, 198 patients were enrolled in a study in 13 centers involving a double-blind parallel group design. After completing a 2-week run-in period on placebo, patients were randomized to receive delapril 7.5 mg twice daily or enalapril 2.5 mg twice daily for 2 weeks. The dose was then doubled for the remaining 6 weeks. In this phase, 1 patient in each group experienced orthostatic hypotension; the dose was then reduced to the initial dose for study completion. A total of 195 patients received active treatment (96 delapril, 99 enalapril). After 8 weeks' treatment, bicycle ergometry demonstrated a significant increase in exercise duration (p < 0.01) and workload (p < 0.01). Echo Doppler investigations showed a significant reduction (p < 0.01) in left ventricular end-systolic volume associated with a significant increase (p < 0.01) in ejection fraction and cardiac output. No clinically significant changes in blood pressure, heart rate, electrocardiogram, or biochemical and hematologic tests were found. There were no significant differences between treatment groups. Three patients in each group experienced adverse reactions requiring withdrawal of 1 patient in each group. Delapril 15 mg twice daily, like enalapril 5 mg twice daily, was effective in improving signs and symptoms of CHF and was well tolerated.
Assuntos
Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Enalapril/uso terapêutico , Insuficiência Cardíaca/tratamento farmacológico , Indanos/uso terapêutico , Administração Oral , Adulto , Idoso , Análise de Variância , Inibidores da Enzima Conversora de Angiotensina/administração & dosagem , Inibidores da Enzima Conversora de Angiotensina/efeitos adversos , Método Duplo-Cego , Ecocardiografia Doppler , Enalapril/administração & dosagem , Enalapril/efeitos adversos , Teste de Esforço , Feminino , Insuficiência Cardíaca/fisiopatologia , Humanos , Indanos/administração & dosagem , Indanos/efeitos adversos , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Resultado do TratamentoRESUMO
The author performed a pilot study of nicardipine (NC), a Ca(+)+ channel blocker, to study its dosing, toxicity, and possible efficacy for hemispheric cerebral infarction within 12 hours (mean 6.9 hr) of onset to determine the advisability of proceeding with a multi-centered controlled trial. NC was administered IV (3 to 7 mg/hr) X 72 hours by titrating dose to mean arterial blood pressure (MABP not less than 10% of baseline), then orally X 30 days. Forty-three patients have been entered; mean age 63 (range 34-89), 25 male and 18 female. Only 3 had CT evidence of infarct on entry. Results have shown improvement in a 100-point (pt) graded exam (40 pts at entry, 68 pts at 3 months). Of 20 patients completing 3 months' evaluation, 17 improved and none worsened. Sixteen out of 20 were at home and 8 had minimal or no impairment. Mean Barthel's index was 72. Mean maximal serum NC level was 75 ng/mL. MABP decreased from 103 (entry) to 83 (72 hours). A larger controlled study is warranted to determine the efficacy of NC for acute cerebral infarct.
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Isquemia Encefálica/tratamento farmacológico , Nicardipino/uso terapêutico , Doença Aguda , Adulto , Idoso , Idoso de 80 Anos ou mais , Pressão Sanguínea/efeitos dos fármacos , Pressão Sanguínea/fisiologia , Isquemia Encefálica/mortalidade , Isquemia Encefálica/fisiopatologia , Relação Dose-Resposta a Droga , Avaliação de Medicamentos , Feminino , Humanos , Infusões Intravenosas , Masculino , Pessoa de Meia-Idade , Nicardipino/efeitos adversos , Nicardipino/sangue , Projetos PilotoRESUMO
Several aspects of congestive heart failure are discussed in the light of international literature and of recent findings of our group. The annual incidence of heart failure in elderly subjects, aged >or=75y, is 13 to 50/1000, while it is 1.6/1000 in people aged 45-54 y. The prevalence of heart failure is about 3% in subjects aged 45-64% in subjects aged more than 65 y and 10% in subjects aged more than 75 y. These data are confirmed by our population based study in elderly subjects. The etiology of congestive heart failure is similar in elderly and middle-aged patients. However, several anatomo-functional, hormonal and autonomic nervous system changes, typical of congestive heart failure, occur during physiologic ageing processes also. These findings may explain the dramatic evolution of congestive heart failure in elderly patients. Moreover, some features of the elderly - e.g. comorbidity, atypical clinical presentations, loss of autonomy, increased iatrogen risk should be considered. No specific drugs exist for the pharmacologic treatment of heart failure in the elderly, so that the geriatric specificity in the treatment of heart failure can be recognized in the art of drug choice and dosage, to obtain the best results with the least side effects. The multiple etiology of congestive heart failure, the comorbidity, the loss of autonomy and the deterioration of cognitive functions suggest the need for multidimensional approach and continuative intervention in elderly patients with heart disease, and in particular with congestive heart failure. Further studies on disease- and age-related changes are necessary to develop new and more potent strategies to secure 'successful ageing'.
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In the present paper we discuss two issues about relationships between congestive heart failure and the brain. First, major acute cerebrovascular events are very frequent among elderly people, but stroke does not appear to be frequently associated with congestive heart failure. Second, some cardiovascular conditions may determine progressive damage of cerebral tissue, with consequent impairment of cognitive functions. The association of cognitive impairment and cardiovascular diseases may dramatically increase morbility and mortality risks in the elderly. Recent studies seem to show that hypotension and congestive heart failure are risk factors for dementia in elderly people. In view of this data, an Italian multicentric study on congestive heart failure in hospitalized elderly patients (CHF Italian Study I) included a brief screening of cognitive abilities (MMSE). The presence of congestive heart failure induced a significant decrease of MMSE scores: mean MMSE score after statistical adjustment for the other variables was about one point lower in patients with congestive heart failure respect to elderly patients affected by heart disease but without congestive heart failure. A novel multicentric study (CHF Italian Study II) has been performed to identify cognitive functions more specifically impaired during congestive heart failure in the elderly. Preliminary data relative to 385 patients, confirmed that congestive heart failure may induce a generalized impairment of cognitive functions. These data have relevant clinical implications because they demonstrate that a multidisciplinary approach is necessary in these patients, both for prevention and rehabilitation therapy.
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To determine which of the many clinical parameters routinely collected influence mortality in patients with low left ventricular ejection fraction (LVEF) (< 45% at radionuclide ventriculography), 128 elderly patients (mean age 79 +/- 3 years) with various heart diseases were prospectively followed for 3 years. Twenty-eight-percent had coronary heart disease, 16% hypertensive heart disease, 7% valvular heart disease. The remaining 62 patients (48%) made up a group comprising patients with primitive cardiomyopathy, cor pulmonary with no evidence of coronary heart disease, valvular disease or hypertensive heart disease. Thirty-four-percent of all patients were classified as having congestive heart failure (CHF). Age, sex and 37 clinical variables were analyzed using a Cox proportional model. Forty-four patients died, 36 (82%) of sudden cardiac death. Ten characteristics at study entry predicted an increased mortality risk: S3 gallop, number of clinical signs >or= 3, LVEF
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A variety of eyelid movement abnormalities have been attributed to lesions of the central nervous system. Apraxia of lid movements, and especially of lid opening, has received the least attention. We present 2 cases of lid opening apraxia and propose that this abnormality may be due to right hemisphere dysfunction.
Assuntos
Apraxias/etiologia , Infarto Cerebral/complicações , Doenças Palpebrais/etiologia , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , MasculinoRESUMO
Calcium channel blockers such as nicardipine improve outcome after global cerebral ischemia and may attenuate ischemic neuronal injury by preventing calcium influx and binding to calmodulin. We followed the temporal and regional sequence of neuronal calcium-calmodulin binding in normal rats (n = 6), untreated ischemic rats (n = 15), and ischemic rats treated with 0.05 mg/kg/hr s.c. nicardipine (n = 13). After 30 minutes of four-vessel occlusion, 40-microns brain sections were incubated in an anti-calmodulin antibody specific for calmodulin not bound to calcium and brain protein. Light-microscopic sections were examined immediately after ischemia and after 2 and 24 hours of reperfusion. Extensive staining of unbound calmodulin was seen in all hippocampal regions and in the cortex in normal rats. In untreated ischemic control rats, staining was lost, indicating calcium-calmodulin binding immediately after ischemia in all regions. However, after 24 hours, staining returned to normal in the cortex and dentate, and minimal staining returned in CA1 and CA3. Nicardipine-treated animals had significantly less calcium-calmodulin binding in CA1 and in the dentate after 2 hours of reperfusion. This study demonstrates that in clinically relevant doses nicardipine has a limited effect on calcium-calmodulin binding in selectively vulnerable regions after severe ischemia.
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Encéfalo/metabolismo , Cálcio/metabolismo , Calmodulina/metabolismo , Ataque Isquêmico Transitório/metabolismo , Nicardipino/uso terapêutico , Animais , Bloqueadores dos Canais de Cálcio/uso terapêutico , Ataque Isquêmico Transitório/tratamento farmacológico , RatosRESUMO
We performed a placebo-controlled trial on the effects of a combined antihypertensive treatment with delapril, a new nonsulfhydryl angiotensin-converting enzyme inhibitor, and indapamide, a sulfonamide diuretic. We studied 28 elderly patients aged 65-85 years (mean age, 69 +/- 1 years) who took 30 mg delapril in combination with 1.25 mg indapamide once daily for 24 weeks. In the present study (performed simultaneously with our trial on the effects of delapril/indapamide on left ventricular mass in elderly patients with hypertension and on the same patients), we report the effects of this drug combination on glomerular filtration rate. Sitting arterial pressure (mean +/- SE) decreased from 156 +/- 1. 5/101 +/- 1 mm Hg at baseline to 133 +/- 1/73 +/- 1 mm Hg at the end of the 24-week treatment period (p < 0.0001). No significant changes in heart rate or episodes of orthostatic hypotension were observed. Glomerular filtration rate increased from 91.8 +/- 4.42 mL/min at baseline to 106.3 +/- 4.5 mL/min (p < 0.001) at the end of treatment. Our results show that the combination of delapril and indapamide is effective in the elderly hypertensive patient, with a favorable effect on the prevention of deterioration of kidney function.
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Inibidores da Enzima Conversora de Angiotensina/administração & dosagem , Anti-Hipertensivos/administração & dosagem , Taxa de Filtração Glomerular/efeitos dos fármacos , Hipertensão/tratamento farmacológico , Indanos/administração & dosagem , Indapamida/administração & dosagem , Idoso , Idoso de 80 Anos ou mais , Quimioterapia Combinada , Feminino , Humanos , Hipertensão/fisiopatologia , Indanos/farmacologia , Indapamida/farmacologia , Masculino , Método Simples-CegoRESUMO
What predisposes some cocaine users to its complications is not known. Because cocaine is metabolized by plasma cholinesterase enzyme, we evaluated this enzyme in 14 patients with cocaine-induced complications, 11 long-term cocaine users from Bolivia, 14 persons in the United States without any documented cocaine-induced complications, and 14 subjects who have not used cocaine. The enzyme was found to be significantly lower in patients with cocaine-induced complications as compared to other groups (p < 0.05). A low level of plasma cholinesterase enzyme may predict complications from cocaine use.
Assuntos
Colinesterases/sangue , Cocaína/efeitos adversos , Adulto , Ecocardiografia , Humanos , Masculino , Infarto do Miocárdio/sangue , Infarto do Miocárdio/induzido quimicamente , Valores de ReferênciaRESUMO
We evaluated several doses of cis-4-(phosphonomethyl)-2-piperidine-carboxylic acid (CGS-19755), a potent competitive N-methyl-D-aspartate (NMDA) receptor antagonist, systemically administered either before or after 20 to 30 minutes of global ischemia in rats. We measured outcome by mortality, histological damage by light microscopy, and learning ability on an eight-arm maze, and determined the drug's mechanism of action by an immunohistochemical assay of calcium-calmodulin binding. High-dose treatment begun prior to ischemia resulted in reduced cellular damage in severely ischemic hippocampal tissue, but also caused high mortality due to respiratory depression. Treatment begun 30 minutes after ischemia resulted in little histological protection but significantly improved learning ability when tested 1 month after ischemia, and did not increase mortality. Furthermore, CGS-19755, 10 mg/kg intraperitoneally, begun either before or after ischemia substantially reduced calcium influx into ischemic neurons as evidenced by reduced calcium-calmodulin binding. We conclude that CGS-19755 prevents calcium entry into ischemic neurons and may be effective therapy for very acute cerebral ischemia.
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Cálcio/metabolismo , Calmodulina/metabolismo , Ataque Isquêmico Transitório/tratamento farmacológico , Ácidos Pipecólicos , Piperidinas/uso terapêutico , Receptores de Neurotransmissores/fisiologia , Animais , Relação Dose-Resposta a Droga , Ataque Isquêmico Transitório/metabolismo , Ataque Isquêmico Transitório/mortalidade , Masculino , Piperidinas/farmacologia , Ratos , Ratos Endogâmicos , Receptores de N-Metil-D-Aspartato , Receptores de Neurotransmissores/efeitos dos fármacosRESUMO
We correlated the efficacy of several clinically relevant pharmacotherapies with their ability to prevent calcium influx into neurons and subsequent binding to calmodulin. We studied the administration of CGS 19755, nimodipine, nicardipine, and combinations of these drugs before or immediately after ischemia in globally ischemic rats. Calcium-calmodulin binding was graded by an immunohistochemical assay after 2 and 24 hours of reperfusion (n = 5-6 at each time period), and histologic damage was graded by light microscopy after 72 hours of reperfusion (n = 6). Calcium-calmodulin binding correlated with the severity of delayed histologic damage in various brain regions. In untreated ischemic control rats, marked calcium-calmodulin binding was seen in CA1 and CA3 after 24 hours of reperfusion (p less than or equal to 0.01). Administered before ischemia, CGS 19755 prevented calcium-calmodulin binding across all brain regions after 2 and 24 hours of reperfusion compared with controls (p less than or equal to 0.05). This effect was most prominent in CA3 and CA1, where the drug also reduced delayed neuronal damage (p less than or equal to 0.05). Lower doses or postischemic administration of CGS 19755, nimodipine, nicardipine, and a combination of postischemic CGS 19755 and nicardipine had a more limited effect on calcium-calmodulin binding and did not protect against delayed neuronal damage.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Isquemia Encefálica/metabolismo , Cálcio/metabolismo , Calmodulina/metabolismo , Hipocampo/metabolismo , Neurônios/metabolismo , Ácidos Pipecólicos , Animais , Hipocampo/efeitos dos fármacos , Hipocampo/fisiopatologia , Neurônios/efeitos dos fármacos , Nicardipino/farmacologia , Nimodipina/farmacologia , Piperidinas/farmacologia , RatosRESUMO
Presynaptic release of glutamate into the extracellular compartment and activation of receptor-operated calcium channels may contribute to ischemic neuronal damage. We evaluated the effect of baclofen, a selective inhibitor of presynaptic glutamate release, on mortality, working memory, and light microscopic hippocampal and cortical damage in the four-vessel occlusion model of cerebral ischemia using 64 male Wistar rats. Baclofen (10 mg/kg i.p.) given 1 hour before and 30-60 minutes after 20 minutes of global ischemia did not lessen mortality, prevent ischemic cellular damage, or significantly improve working memory compared with no treatment. We conclude that preischemic and postischemic administration of baclofen does not protect neurons from ischemic injury.