Reduction in temporal N-acetylaspartate and creatine (or choline) ratio in temporal lobe epilepsy: does this 1H-magnetic resonance spectroscopy finding mean poor seizure control?

BACKGROUND—Proton magnetic resonance spectroscopy(¹H-MRS) is a potentially useful tool in the in vivoinvestigation of brain metabolites in intractable temporal lobeepilepsy (TLE). Focal N-acetylaspartatate (NAA) reductions have beencorrelated with mesial temporal sclerosis (MTS) in surgically resectedepileptogenic foci.
OBJECTIVE—To evaluate the abnormalities in themetabolites NAA, creatine+ phosphocreatine (Cr), and cholinecontaining compounds (Cho) in the temporal lobe of medically refractorypatients with temporal lobe epilepsy, seizure free patients withtemporal lobe epilepsy, and normal controls.
PATIENTS AND METHODS—Ten refractory patients, 12 seizure free patients with temporal lobe epilepsy, and 10 age matchednormal controls were studied by ¹H-magnetic resonancespectroscopy. All patients had consistently unilateral temporal EEGabnormalities and a normal brain MRI. Proton MR spectra were obtainedfrom an 8 ml volume in the medial temporal lobes in patients withtemporal lobe epilepsy (ipsilateral to EEG foci) and the normalcontrols. The signals measured were expressed in terms of NAA/Cr,NAA/Cho, and Cho/Cr.
RESULTS—When compared with seizure free patientswith temporal lobe epilepsy and normal controls, the 10 refractorypatients with temporal lobe epilepsy had a lower mean (SEM) NAA/Crratio (1.65(0.53) v 2.62 (0.60), and 2.66 (0.73);p<0.002 and p<0.006) and a lower mean NAA/Cho ratio (1.59 (0.79)v 2.83 (1.33) and 2.58(0.67); p<0.02 andp<0.007).Furthermore, the two patients showing the lowest NAA/Cr ratios (1.47 and 1.73) in the seizure free group had had a past period of poorseizure control.
CONCLUSIONS—There were reduced temporal NAA/Cr andNAA/Cho ratios, suggesting neuronal loss or damage, associated withpast or present poor seizure control in the patients with temporal lobeepilepsy, but it does not exclude the possibility of a future completeseizure control (seizure free patients with temporal lobe epilepsy at the time of ¹H-MRS). This study warrants further¹H-MRS investigation with a larger series of patients withtemporal lobe epilepsy.

     

Exercise training and dietary chromium effects on glycogen, glycogen synthase, phosphorylase and total protein in rats

The effects of exercise training and dietary chromium intake on rat liver and muscle glycogen metabolism, tissue and body weight and feed consumption were examined. After 16 wk of training, liver, gastrocnemius and biceps femoris glycogen concentrations were higher in the trained compared to sedentary groups, independent of dietary chromium. There was a chromium x training interaction on glycogen synthase activities in the liver and gastrocnemius muscle. Liver glycogen phosphorylase activities (expressed per g liver) were lower in the chromium-supplemented rats as compared to the non-supplemented rats after 5 wk of dietary treatment, but were similar after 8 wk and higher after 18 wk. Gastrocnemius phosphorylase activity (expressed per mg protein) was lower in the trained rats as compared to the sedentary rats after 16 wk, independent of dietary chromium. Biceps femoris phosphorylase activities were not altered due to training or dietary chromium. Total protein concentration increased in the liver but decreased in the gastrocnemius due to dietary chromium. In summary, liver glycogen synthase and phosphorylase activities were dependent upon dietary chromium. Dietary chromium altered gastrocnemius synthase, but not phosphorylase activities. Changes in enzyme activities may be related to the chromium-dependent effects on liver protein and the chromium and training-dependent effects on gastrocnemius total protein.     

Endocytosis of gold-labeled proteins and LDL byTrypanosoma cruzi

Endocytosis was studied at the ultrastructural level in different developmental forms ofTrypanosoma cruzi after incubation of the parasites in the presence of gold-labeled proteins (albumin-Au, peroxidase-Au and transferrin-Au) and low-density lipoprotein (LDL-Au). Epimastigote (culture) forms actively ingested LDL and proteins. Initially, gold particles were seen adhering only to the cytostome and inside the flagellar pocket. In parasites incubated at 4°C with transferrin-Au or peroxidase-Au, labeling was found only at these two sites, showing that receptor-mediated endocytosis occurs in both regions. In the cytoplasm, gold particles were seen only inside two different compartments: membrane-bound vesicles and reservosomes. Incubation of epimastigotes with acridine orange followed by fluorescence microscopy revealed intense orange staining, indicating that the reservosomes have an acidic pH. This staining was abolished after incubation of the parasites in the presence of ammonium chloride. These data confirm that this compartment is the site of accumulation of ingested lipids and proteins. Little intracellular labeling with transferrin-Au was found in in vitro — derived amastigotes and trypomastigotes (both lack reservosomes). However, although in amastigotes very few gold particles were seen bound to the cells, in trypomastigotes they were observed bound to the membrane that encloses the cell body, the flagellar pocket, and the flagellum, suggesting that the receptors are more abundant in this form.     

Shoulder instability: impact of glenohumeral arthrotomography on treatment

We used arthrotomography to study the glenoid labrum in 114 patients. Sixty-nine of the patients had anatomic instability of the shoulder (including recurrent dislocation and subluxation of the shoulder), and 45 patients had functional instability of the shoulder (denoted by chronic pain, clicking of the joint, and the sensation that an unstable condition exists without the objective signs of it). Labral tears were revealed arthrotomographically in 86% of the patients with anatomic instability, while only 40% of the patients with functional instability had labral abnormalities, and these were primarily of minor severity. Fifty-six patients (44 of whom had anatomic instability; 12, functional instability) required surgery. The surgical findings were correlated with the arthrotomographic findings, and no false-positive results were revealed. However, arthrotomography demonstrated only part of the pathologic condition of two patients. These results confirm that there is a strong correlation between labral pathologic conditions and anatomic instability of the shoulder. Arthrotomographic studies have a great impact on the selection of therapy in cases of both anatomic and functional instability of the shoulder.     

Differential maturation of brainstem auditory evoked potentials in preterm infants according to birthweight.

Brainstem auditory evoked potentials (BAEPs) were recorded from 39 preterm infants, divided into 3 groups: small-for-gestational-age, with a birthweight less than or equal to 1500 g (SGA); appropriate-for-gestational-age, with a birthweight less than or equal to 1500 g (AGA1); and appropriate-for-gestational-age, with a birthweight higher than 1500 g (AGA2). A significant shortening of the I-V interval due to an increase in wave I latency was found in the SGA group. The lower-weight AGA group (AGA1) was never significantly different from the SGA group. Although there was no correlation between conceptional age and weight at the time of the examination for the studied population, negative correlations were found between wave I latency and weight at the time of the examination. These findings confirm previous research and suggest the existence of a link between weight and basal cochlear maturation.     

Venous skin flaps: an experimental study and report of two clinical distal island flaps

An experimental study of saphenous flaps in 26 dogs is reported, which confirmed the work of Baek et al. (1985) that venous flaps can survive. In addition, it showed that venous island flaps could survive after division of the venous pedicle proximally or distally, or as free flaps, providing through flow was re-established by venous anastomoses. In this study no flaps survived on a single venous pedicle without through flow. Two successful clinical cases of venous flaps are also reported, in which through flow was re-established by a simple venous anastomosis. One of these flaps threatened to become necrotic until the thrombosed anastomosis was successfully redone.     

儿童癌症试验性疗法是否优于标准疗法：儿童肿瘤研究组的多项随机临床对照试验的观察研究

目的:比较儿童期癌症标准疗法与Ⅲ期随机化临床试验阶段所验证的新疗法,研究新疗法优于或劣于标准疗法的概率;此类临床试验中,纳入患者的民族因素可能对试验结果造成不确定性影响,所以,本文还研究新疗法的成功和失败模式是否与前述不确定性影响之间存在一致性。试验设计:临床观     

Ultrastructural aspects ofTrypanosoma (Megatrypanum) freitasi in co-cultivation with mammalian cells

Cultures ofTrypanosoma (Megatrypanum) freitasi with L929 mouse fibroblasts at 27.5°C were examined by scanning and transmission electron microscopy in an attempt to clarify the processes of colony formation by the epimastigotes and of their attachment to substrata. It was seen that the flagellates occupy intercellular spaces and do not associate with intact fibroblasts. As the trypanosome population increases, ever larger portions of the substratum are cleared of fibroblasts and occupied by conglomerates of epimastigote colonies consisting of about a dozen organisms that attach to the substratum by their anterior extremities and form pyramidal clusters. Attachment of the epimastigotes involves the flagellar membrane, which becomes extraordinarily enlarged and assumes various aspects of broad sheets, filaments and loops over the substratum or along the flagellum, which exhibits a shortened axoneme. Desmosome or hemidesmosome plaques are present when the attachment takes place between membranes or between the membrane and the substratum.Supported by grants from CNPq and FINEP