Synthesis, photochemical and in vitro cytotoxic evaluation of benzoselenazole-based aminosquaraines.

Squaraine dyes have recently attracted interest as potential second generation photosensitizers for photodynamic therapy. Several cationic aminosquaraine dyes bearing benzoselenazole terminal nuclei were synthezised and their cytotoxic activity was tested against four different human tumor cell lines - breast (MCF-7), non-small cell lung (NCI-H460), cervical (HeLa) and hepatocellular (HepG2) carcinomas - and against a non-tumor porcine liver primary cell line (PLP2), both in the absence of light and under irradiation. All dyes, which displayed strong absorption within the phototherapeutic window, were found to exhibit photodynamic activity and were shown to be, in most cases, more cytotoxic, both in the dark and upon irradiation, than their benzothiazole analogues.

Structures, Activities and Drug-Likeness of Anti-Infective Xanthone Derivatives Isolated from the Marine Environment: A Review.

Marine organisms represent almost half of total biodiversity and are a very important source of new bioactive substances. Within the varied biological activities found in marine products, their antimicrobial activity is one of the most relevant. Infectious diseases are responsible for high levels of morbidity and mortality and many antimicrobials lose their effectiveness with time due to the development of resistance. These facts justify the high importance of finding new, effective and safe anti-infective agents. Among the variety of biological activities of marine xanthone derivatives, one that must be highlighted is their anti-infective properties. In this work, a literature review of marine xanthones with anti-infective activity, namely antibacterial, antifungal, antiparasitic and antiviral, is presented. Their structures, biological activity, sources and the methods used for bioactivity evaluation are described. The xanthone derivatives are grouped in three sets: xanthones, hydroxanthones and glycosylated derivatives. Moreover, molecular descriptors, biophysico-chemical properties, and pharmacokinetic parameters were calculated, and the chemical space occupied by marine xanthone derivatives is recognized. The chemical space was compared with marketed drugs and framed accordingly to the drug-likeness concept in order to profile the pharmacokinetic of anti-infective marine xanthone derivatives.

Aminosquaraines as potential photodynamic agents: Synthesis and evaluation of in vitro cytotoxicity.

The synthesis of several aminosquaraine cationic dyes displaying strong absorption within the so-called phototherapeutic window (650-850nm) is described. Their cytotoxicity, under dark and illuminated conditions, was tested against several human tumor cell lines (breast, lung, cervical and hepatocellular carcinomas) and non-tumor porcine liver primary cells. All compounds showed to inhibit the growth of the tumor cells upon irradiation more than in the absence of light, in more or less extension, clearly exhibiting photodynamic activity. The photosensitizing ability against some cell lines, together with the low toxicity for the non-tumor primary PLP2 cells displayed by some of the compounds synthetized, turns them into potential candidates as photosensitizers for PDT.

Identification of Dihydropyrazolo[1,5-a]pyrazin-4(5H)-ones as Cyclic Products of ß-Amidomethyl Vinyl Sulfone Alphavirus Cysteine Protease Inhibitors.

Optimized syntheses of (E)-5-(2-ethoxyphenyl)-N-(3-(methylsulfonyl)allyl)-1H-pyrazole-3-carboxamide (RA-0002034, 1), a promising antiviral covalent cysteine protease inhibitor lead, were developed. The syntheses avoid the contamination of 1 with the inactive cyclic dihydropyrazolo[1,5-a]pyrazin-4(5H)-one 2, which is formed by the intramolecular aza-Michael reaction of the vinyl sulfone warhead under basic conditions and slowly at pH 7.4 in phosphate buffer. The pure cysteine protease inhibitor 1 could be synthesized using either modified amide coupling conditions or through the introduction of a MOM-protecting group and was stable as a TFA or HCl salt. Although acyclic 1 demonstrated poor pharmacokinetics with high in vivo clearance in mice, inactive cyclic 2 showed improved plasma exposure. The potential use of cyclic dihydropyrazolo[1,5-a]pyrazin-4(5H)-ones as prodrugs for the acyclic ß-amidomethyl vinyl sulfone warhead was demonstrated by GSH capture experiments with an analog of 2.

Prebiotic triose glycolysis promoted by co-catalytic proline and phosphate in neutral water.

Proline and phosphate promote a near-quantitative aldol reaction between glycolaldehyde phosphate and formaldehyde at neutral pH in water. Our results demonstrate the important role of general acid-base catalysis in water and underscore the essential role that amino acid catalysis may have played in early evolution of life's core metabolic pathways.

How can we improve embryo production and pregnancy outcomes of Holstein embryos produced in vitro? (12 years of practical results at a California dairy farm).

Genomic evaluations have revolutionized dairy cattle breeding, and the demand for embryos produced from very young heifers with high genetic merit has increased over time. The combination of low oocyte recovery, young age of donors, and milk production status can make the in vitro embryo production (IVP) of Holstein cattle incredibly challenging. Several factors need to be coordinated to obtain a live calf from an IVP embryo, but the quality of the oocyte at the start of the process is one of the key factors. Aspects related to oocyte quality, laboratory quality control, embryo quality and recipient selection are addressed here, based on the measures that the RuAnn Genetics Laboratory (Riverdale, California, USA) adopted in the last 12 years, with the goal of improving production of live, healthy calves from Holstein embryos. Follicular wave synchronization and stimulation with follicular stimulating hormone (FSH) is necessary to improve oocyte quality and consequently embryo production. Laboratory quality control and the use of high-quality supplies are essential to reduce variability in production and facilitate identification of other factors that might interfere with embryo production. High pregnancy rates can be achieved with good quality embryos selected at optimal time and stage of development, transferred by an experienced embryo transfer (ET) technician, to well managed recipients 7 or 8 days after estrus. Attention to detail at every step of the process is crucial to success.

Yicathins B and C and Analogues: Total Synthesis, Lipophilicity and Biological Activities.

Natural products have always been an important source of new hits and leads in drug discovery, with the marine environment being regarded as a significant source of novel and exquisite bioactive compounds. Yicathins B and C are two marine-derived xanthones that have shown antibacterial and antifungal activity. Herein, the total synthesis of these yicathins and six novel analogues is reported for the first time. As marine natural products tend to have very lipophilic scaffolds, the lipophilicity of yicathins and their analogues was evaluated in the classical octanol/water system and a biomimetic model-based system. As the xanthonic nucleus is a "privileged structure", other biological activities were evaluated, namely antitumor and anti-inflammatory activities. An interesting anti-inflammatory activity was identified for yicathin analogues that paves the way for the design of dual activity (anti-infective and anti-inflammatory) marine-inspired xanthone derivatives.

Ipsilesional trajectory control is related to contralesional arm paralysis after left hemisphere damage.

We have recently shown ipsilateral dynamic deficits in trajectory control are present in left hemisphere damaged (LHD) patients with paresis, as evidenced by impaired modulation of torque amplitude as response amplitude increases. The purpose of the current study is to determine if these ipsilateral deficits are more common with contralateral hemiparesis and greater damage to the motor system, as evidenced by structural imaging. Three groups of right-handed subjects (healthy controls, LHD stroke patients with and without upper extremity paresis) performed single-joint elbow movements of varying amplitudes with their left arm in the left hemispace. Only the paretic group demonstrated dynamic deficits characterized by decreased modulation of peak torque (reflected by peak acceleration changes) as response amplitude increased. These results could not be attributed to lesion volume or peak velocity as neither variable differed across the groups. However, the paretic group had damage to a larger number of areas within the motor system than the non-paretic group suggesting that such damage increases the probability of ipsilesional deficits in dynamic control for modulating torque amplitude after left hemisphere damage.

Functional magnetic resonance and spectroscopy in drug and substance abuse.

OBJECTIVES: Functional magnetic resonance imaging (fMRI) and proton magnetic resonance spectroscopy (1H-MRS) were utilized to evaluate functional and metabolic brain changes in drug abusers. METHODS: Functional neuroimaging studies in alcohol, cocaine, cigarette, and cannabis abusers were reviewed in the medical literature from 2000 to 2005. RESULTS: Brain activation with functional magnetic resonance imaging is different in drug abusers and may show more or less activation according to the task and gender. Lower concentrations of N-acetylaspartate and higher creatine are usually seen with 1H-MRS in the brains of cigarette smokers, people who are cocaine dependent, and alcohol abusers. CONCLUSIONS: Neural substrates of drug addition, craving, drug interaction, individual abstinence, and drug withdrawal can be studied with functional magnetic resonance imaging and proton magnetic resonance spectroscopy.

Proton magnetic resonance spectroscopy of brain tumors correlated with pathology.

RATIONALE AND OBJECTIVES: Evaluate proton magnetic resonance spectroscopy ((1)H-MRS) for assessing and grading brain tumors. MATERIALS AND METHODS: The research was done at Detroit Medical Center in a 1.5-T Siemens MR magnet using single-voxel or multivoxel MRS. This study consisted of 27 patients: 10 females and 17 males ages 22-83 years (average age 43.8). The data were recorded for three peaks-N-acetyl aspartate (NAA), choline (Cho), creatine (Cr)-which were used to calculate the ratios Cho/NAA and Cho/Cr. RESULTS: Abnormal spectra were seen in 25 patients and normal spectra in 2. In 16 patients with brain astrocytoma of various grades, the pathology grading was correlated with Cho/NAA and Cho/Cr. These values were 6.53 and 3.35 for nine patients with Grade 4 astrocytoma; 1.85 and 1.62 for three patients with Grade 3 astrocytoma; 2.21 and 1.50 for three patients with Grade 2 astrocytoma; and 1.45 and 1.49 for one patient with Grade 1 astrocytoma. The remaining nine patients with abnormal spectra were also correlated with pathology. CONCLUSION: MRS ratios can be used to differentiate malignant and nonmalignant lesions from normal brain tissue. In general, high-grade astrocytoma have higher Cho/NAA and Cho/Cr ratios compared with low-grade astrocytoma.

Neural correlates of telling lies: a functional magnetic resonance imaging study at 4 Tesla.

RATIONALE AND OBJECTIVE: Intentional deception (ie, lying) is a complex cognitive act, with important legal, moral, political, and economic implications. Prior studies have identified activation of discrete anterior frontal regions, such as the ventrolateral prefrontal cortex (VLPFC), dorsolateral prefrontal cortex (DLPFC), dorsal medial prefrontal cortex (DMPFC), and anterior cingulate cortex (ACC) during deception. To extend these findings, we used novel real-time functional magnetic resonance imaging (fMRI) technology to simulate a polygraph experience in order to evoke performance anxiety about generating lies, and sought to ascertain the neural correlates of deception. MATERIALS AND METHODS: In this investigational fMRI study done with a 4-T scanner, we examined the neural correlates of lying in 14 healthy adult volunteers while they performed a modified card version of the Guilty Knowledge Test (GKT), with the understanding that their brain activity was being monitored in real time by the investigators conducting the study. The volunteers were instructed to attempt to generate Lies that would not evoke changes in their brain activity, and were told that their performance and brain responses were being closely monitored. RESULTS: Subjects reported performance anxiety during the task. Deceptive responses were specifically associated with activation of the VLPFC, DLPFC, DMPFC, and superior temporal sulcus. DISCUSSION: These findings suggest the involvement of discrete regions of the frontal cortex during lying, and that the neural substrates responsible for cognitive control of behavior may also be engaged during deception.

Magnetic Resonance Imaging in Chronic Chagas' Disease: Correlation with Endomyocardial Biopsy Findings and Gallium-67 Cardiac Uptake.

BACKGROUND: We studied the correlation among cardiac magnetic resonance imaging (MRI), gallium-67 myocardial uptake, and right ventricular endomyocardial biopsy results in chronic Chagas' disease. To our knowledge, this represents the first attempt to correlate the histological findings with cardiac MRI and gallium-67 myocardial uptake for noninvasive diagnosis of inflammatory activity associated with Chagas' disease. METHODS: Ten male patients with cardiomyopathy secondary to Chagas' disease were studied (mean age, 47.7 +/- 7 years; congestive heart failure New York Heart Association [NYHA] functional class II [two patients], III [six patients], and IV [two patients]; and mean echocardiographic left ventricular [LV] ejection fraction [EF], 36 +/- 6%). The patients underwent right ventricular endomyocardial biopsy, cardiac MRI, and gallium-67 myocardial uptake testing. The results of this group were compared with those of a control group of patients with idiopathic dilated cardiomyopathy who were matched in age (mean age, 46 +/- 10 years), LV function (mean echocardiographic EF, 30 +/- 4%), and NYHA classification (one patient in class II, five patients in class III, and one patient in class IV). RESULTS: All patients with Chagas' disease showed higher signal intensity on MRI after the administration of gadolinium. The intensity of the septal signal changed from 0.90 +/- 0.11 to 1.56 +/- 0.19 (P < 0.001). In the control group, there was no difference in signal intensity with gadolinium (mean septal intensity, 0.94 +/- 0.12 before and 0.99 +/- 0.15 after; NS). On biopsy, eight chagasic patients had evident signs of myocarditis, and two patients had borderline evidence myocarditis. However, only one patient in the control group had a histological diagnosis of borderline myocarditis. Gallium-67 cardiac uptake was positive for myocardial inflammatory process in seven chagasic patients and borderline in one. On the other hand, only one patient in the control group had an uptake that was positive for inflammation, and one had a borderline result. CONCLUSIONS: In conclusion, the data from this study strongly suggest that myocarditis is frequently found in Chagas' disease. Cardiac MRI appears to be an accurate and alternative method for the diagnosis of inflammatory process associated with Chagas' disease.

Extraparenchymal neurocysticercosis in Albuquerque, New Mexico.

BACKGROUND: neurocysticercosis (NCC) prevalence is increasing throughout the United States mainly because of immigration from Latin America. Clinicians may fail to recognize the extraparenchymal disease because they do not consider the diagnosis. METHODS: to analyze neuroimaging and clinical characteristics of extraparenchymal NCC, we retrospectively reviewed all such cases presenting to a major general medical school hospital in the State of New Mexico. RESULTS: eleven (30%) of our 37 cases of NCC diagnosed using standard criteria from 1998 through 2004 had extraparenchymal disease. On neuroimaging, 36% of the patients lacked parenchymal cysts, 64% had intraventricular cysticerci, 64% had subarachnoid cysticerci, and 64% had hydrocephalus due to either basal arachnoiditis or direct obstruction of intraventricular pathways. Lumbar puncture was performed in 6 patients. All had a cerebrospinal fluid (CSF) pleocytosis, none had CSF or blood eosinophilia, and CSF antibody to NCC could be absent while present in serum. Response to treatment was frequently suboptimal. CONCLUSIONS: extraparenchymal NCC is more frequent than previously thought. Because clinicians outside the Southwest United States are often unfamiliar with NCC as a cause of chronic meningitis, chronic ventriculitis, or hydrocephalus without obvious cysts, the diagnosis of extraparenchymal NCC often depends on the correct interpretation of neuroimaging.

Diagnóstico pré-natal das cardiopatias congênitas e arritmias pela ecodopplercardiografia / Prenatal diagnosis of congenital heart diseases and cardiac dysrrhythmias by echocardiography

Detectar precocemente cardiopatias congênitas e arritmias pela EcoDopplercardiografia em gestantes pertencentes ao grupo de risco para tais alteraçöes de acordo com as indicaçöes clássicas. Ecocardiografia bidimensional associada ao Modo M e Doppler foi realizada em 200 gestantes pelas seguintes indicaçöes: diabete materna, arritmia fetal, filho anterior com cardiopatia, retardo de crescimento intra-uterino, hidropsia fetal näo imune, rubéola materna, isoimunizaçäo, malformaçöes fetais ao ultra-som, polihidrámnio, gemelidade, oligoâmnio, ingestäo materna de drogas, lupus eritematoso sistêmico e outros. Anormalidades estruturais isoladas foram encontradas em 6 casos e associadas com bradiarritmia em 5 casos (total 5,5%). Arritmias fetais sem malformaçäo cardíaca ocorreram em 30 casos (15%) sendo a extrrasistolia atrial a mais freqüente. Os achados deste estudo inicial indicam que a anatomia e funçäo cardíaca fetal podem ser avaliados com precisäo. Baseados nisto, temos divulgado o método enfatizando suas indicaçöes, com a finalidade de proporcionar cada vez mais assistência adequada ao feto e ao recém-nascido portadores de cardiopatia congênita ou arritmia

Purpose - To detect in prenatal life fetal arrhythmia and congenital heart disease. We performed fetal echocardiography following classical indications according to the literature. Patients and Methods - Two-dimensional echocardiography associated with M-mode and Doppler was performed in 200 patients according to the indications: maternal diabetes, fetal arrhythmia, maternal congenital heart disease, previous fetus with cardiac defect, intrauterine growth retardation, nonimmune fetal hydrops, rubeola, isoimunization, fetal malformation by ultrasound, polyhidramnio, gemelarity, olygohydramnio, maternal ingestion of drugs, lupus and others. Results - Structural abnormalities of the heart were found in 6 cases and associated with bradiarrhythmia in 5 cases (total of 5,5%). Fetal arrhythmias without cardiac malformation were found in 35 cases (17,5%) and premature atrial contractions were the most frequent. Conclusion - The findings in this study indicate that it is possible the accurate definition of the cardiac anatomy and function. We have enphazised the method trying to spread it, objecting to improve assistance to the fetus and newborn with arrhythmias anal or congenital heart disease

Angiografia pela ressonância magnética nos aneurismas intracranianos: estudo comparativo com a angiografia cerebral / Magnetic resonance angiography of intracranial aneurysms: comparative study with cerebral angiography

Avaliamos por angiografia pela ressonância magnética e por angiografia cerebral 41 pacientes com 55 aneurismas intracranianos confirmados pela cirurgia. A angiorressonância detectou 52 aneurismas com sensibilidade de 94,5 por cento e a angiografia cerebral detectou 53 aneurismas com sensibilidade de 96,3 por cento. Pela näo invasibilidade, rapidez e baixo custo a angiorressonância poderá substituir a angiografia cerebral no diagnóstico de aneurismas intracranianos e no prognóstico da hemorragia subaracnóide

Abdominal ultrasonography in hepatolenticular degeneration: a study of 33 patients

O estudo ultra-sonográfico de 33 pacientes com degeneraçäo hepatolenticular revelou as seguintes alteraçöes principais: desordens da ecotextura hepática (29 casos), alteraçöes das dimensöes esplênicas (21), contraçäo do fígado (10), colelitíase (8), hepatomegalia e ascite (1). As desordens da ecotextura hepática se apresentaram sob diversas formas, desde leves até graves alteraçöes da ecogênese hepática, associadas com distorçöes anatômicas do fígado, tais como modificaçöes do perfil e reduçäo das dimensöes. A contraçäo hepática sempre se acompanhou de esplenomegalia. A raridade da hepatomegalia pode ser explicada pelo fato de que a ultra-sonografia foi realizada após o início do tratamento com penicilamina, ou por outros fatores ainda desconhecidos, como a possibilidade de que o cobre possua uma açäo fibrogênica maior do que a de outros agentes hepatotóxicos. A colelitíase foi muito freqüente no sexo feminino (6 de 13 pacientes) e sua incidência tendeu a crescer com a idade. Quanto aos doentes do sexo masculino, näo se notou aumento da incidência em relaçäo à freqüência na populaçäo geral. Os dois únicos pacientes do sexo masculino eram jovens, fato raramente observado nos homens normais

Brain spect in the pre-surgical evaluation of epileptic patients: preliminary results

A avaliaçäo pré-operatória de pacientes epilépticos consiste basicamente de exame neurológico, monitorizaçäo intensiva de EEG e estudos anatômicos (CT e RMN). Métodos funcionais como PET e SPECT têm sido utilizados mais frequentemente nos últimos anos. Foi realizada a investigaçäo pré-operatória em 15 pacientes epilépticos adultos (8 mulheres, 7 homens) utilizando câmara de cintilaçäo rotacional acoplada a computador. As imagens tomográficas foram obtidas 15 minutos após a injeçäo de 99mTC HMPAO. Todos os pacientes foram submetidos a RMN e monitorizaçäo intensiva de EEG, que geralmente inclui registros ictais. cinco pacientes possuiam lesöes expansivas (3 meningiomas e 2 astrocitomas). Em 10 pacientes, os estudos neurorradiológicos näo mostraram presença de lesöes expansivas (2 normais e 8 com lesöes inativas). O estudo de 2 pacientes com meningeomas mostrou presença de hipoperfusäo ao nível da lesäo, enquanto em um terceiro caso marcada hiperperfusäo foi detectada e, neste paciente, provavelmente correlacionava-se quadro de epilepsia partialis continua. Nos pacientes com astrocitomas, os exames de SPECT mostraram hipoperfusäo no local da lesäo. Os dados obtidos em pacientes näo portadores de lesöes expansivas do sistema nervoso mostraram: (a) em 4 casos os achados de SPECT, correlacionaram-se bem aos achados anatômicos; (b) em 5 casos, os achados de SPECT mostraram déficits de fluxo adicionais a lesäo anatomica; (c) em um caso, näo houve correlaçäo entre os achados de SPECT e uma pequena lesäo anatômica. Em 5 casos com lesöes näo progressivas (n = 10) os achados de SPECT foram úteis na determinaçäo da conduta cirúrgica. Apesar do pequeno número e da heterogeneidade da presente amostra, o SEPECT parece ser importante método complementar no arsenal clínico-propedêutico de pacientes epilépticos candidatos a cirurgia

Imagem por ressonância magnética na cardiopatia chagásica crônica. Correlação com biopsia endomiocárdica / Magnetic resonance imaging in chronic chagas' heart disease. Correlation with endomyocardial biopsy findings

PURPOSE: To study the correlation between magnetic resonance imaging of the heart and right ventricle endomyocardial biopsy results in chronic Chagas' heart disease. METHODS: Ten patients with Chagas' disease, mean age 47 +/- 7 years, all males, in congestive heart failure with New York Heart Association class II (2 patients), III (6) and IV (2) were studied. Mean left ventricular ejection fraction was at echocardiogram 36 +/- 6. The patients were submitted to right ventricular endomyocardial biopsy and magnetic resonance imaging of the heart. The results of this group were compared with a control group of patients with idiopathic dilated cardiomyopathy, with mean age of 46 +/- 10 years and left ventricular ejection fraction of 30 +/- 4, in heart failure with functional class II (1 patient), III (5) and IV (1). RESULTS: All patients with Chagas' heart disease presented an increase in magnetic ressonance imaging signal of the heart after gadolinium use. The septal signal intensity changed from 0.87 +/- 0.06 to 1.54 +/- 0.16 (p < 0.001). In the control group the mean septal signal intensity was 0.93 +/- 0.07 before and 0.89 +/- 0.06 after the gadolinium (p = ns). Eight patients of the Chagas' disease group had biopsy proven myocarditis and two had borderline myocarditis. However, only one patient of the control group had diagnosis of borderline myocarditis. CONCLUSION: Myocarditis is frequently found in Chagas' heart disease patients and who unlike controls present a significant increase in myocardial signal intensity after gadolinium infusion. The magnetic resonance imaging of the heart seems a promising alternative method for the diagnosis of an inflammatory process in Chagas' heart disease.

Objetivo - Estudar a correlação entre a imagem por ressonância magnética e a biopsia endomiocárdica do ventrículo direito (VD) na cardiopatia da doença de Chagas. Métodos - Comparação de 10 pacientes com cardiopatia da doença de Chagas, idade média de 47 ± 7 anos, todos do sexo masculino, com insuficiência cardíaca em classe funcional (CF) II NYHA (2 pacientes), III (6) e IV (2); fração de ejeção do ventrículo esquerdo (FEVE) média pelo ecocardiograma 36 ± 6%; e 6 pacientes com cardiomiopatia dilatada idiopática, idade média de 46 ± 10 anos, FEVE média pelo ecocardiograma 30 ± 4% e insuficiência cardíaca CF II (1 paciente), III (5) e IV (1). Todos os pacientes foram submetidos a biopsia endomiocárdica do VD e exame do coração através de ressonância magnética (RM) com e sem uso do contraste gadolíneo. Resultados - Todos os pacientes com cardiopatia chagásica apresentaram aumento da intensidade de sinal na imagem pela RM após o uso de gadolíneo. A intensidade média do sinal variou de 0,87 ± 0,06 antes a 1,54 ± 0,16 após o uso do contraste (p < 0,001). No grupo controle, antes do uso do gadolíneo a intensidade média septal foi de 0,93 ± 0,07 e, após, o valor médio foi de 0,89 ± 0,06 (p = ns). Oito pacientes no grupo de cardiopatia chagásica tiveram biopsia provando miocardite e 2 com resultado bordeline, contudo no grupo controle, somente um teve diagnóstico duvidoso para miocardite. Conclusão - A miocardite é freqüentemente encontrada na doença de Chagas, os pacientes com cardiomiopatia chagásica, ao contrário do grupo controle, apresentam aumento significativo da intensidade de sinal de ressonância após o uso do gadolíneo. A imagem por RM parece ser método alternativo e com boa acurácia para diagnóstico de processo inflamatório cardíaco na doença de Chagas

Avaliação das alterações morfológicas crônicas do músculo grande dorsal, após cardiomioplastia, através da ressonância magnética / Evaluation of chronic morphologic changes In latissimus dorsi after cardiomyoplasty by magnetic ressonance

PURPOSE--Long term clinical and hemodynamic benefits of dynamic cardiomyoplasty (DC) have been reported. However, no information is available about long-term morphological changes in the wrapped latissimus dorsi (LD) muscle in humans. METHODS--The latissimus dorsi muscle flap was evaluated by magnetic resonance imaging (MRI) in 5 patients submitted to DC for treatment of severe dilated cardiomyopathy. All patients were studied from 24 to 52 months after the surgical procedure at the time of the cardiomyostimulator replacement. In the interim, LD was stimulated with burst of 6 pulses (burst duration 185 msec, burst freq 30Hz) synchronized to every cardiac contraction with a maximum of 100 LD contractions/min. Images were acquired on a GE Sigma 1.5 T system (TE = 25ms, TR = R- Rx2, slice thickness 8mm). RESULTS--The thickness of was 7.6 +/- 0.8mm. In addition, the signal intensity of the LD was compared with that of thoracic skeletal muscle and was found to be increased (2.19 +/- 0.42). The signal intensity was similar to that of subcutaneous fat in those images. CONCLUSION--Morphologic changes in the wrapped LD muscle consistent with fatty degeneration occur after DC and can be detected by MRI. Further studies will be necessary to demonstrate the clinical significance of such LD muscle flap changes.

Objetivo - Os benefícios clínicos e hemodinâmicos da cardiomioplastia (CD) a longo prazo têm sido relatados. Contudo existem poucos estudos sobre mudanças morfológicas crônicas no músculo grande dorsal (GD) em pacientes submetidos à cirurgia. Métodos - Avaliação através da ressonância magnética (RM) do músculo GD de 5 pacientes no período entre 24 e 52 meses após procedimento cirúrgico, no momento de substituição do cardiomioestimulador. Nesse interim, o GD foi estimulado com seqüência de 6 pulsos (duração de 185ms e freqüência de 30Hz) sincronizado com todas as contrações cardíacas, com um máximo de 100 contrações do GD por minuto. As imagens foram adquiridas pelo aparelho 1,5 Tesla da GE (tempo-echo, 25ms; tempo de repetição, R-R x 2 e espessura do corte, 8mm). Resultados - A espessura média do GD foi de 7,6±0,8mm; a intensidade do sinal do GD foi comparada com a do músculo esquelético do tórax, apresentando-se aumentada (2,19±0,42 proximal e 2,01±0,49 distal). A intensidade do sinal do GD foi similar a da gordura subcutânea da parede do tórax (2,01±0,49 vs 2,67±0,6, P=NS). Conclusão - Mudanças morfalógicas no músculo GD ocorrem após CD, e podem ser detectadas pela RM. Estudos adicionais serão necessários para demonstrar o significado clínico de tais mudanças do músculo GD