Cytogenetic analysis of 100 consecutive newly diagnosed cases of acute lymphoblastic leukemia in Rio de Janeiro

We report the cytogenetic analysis of newly diagnosed Brazilian children with acute lymphocytic leukemia (ALL). We investigated 100 ALL cases from four different institutions in Rio de Janeiro. The frequency of chromosomal abnormalities was 92.3%. The karyotype profile and recurrent abnormalities found in this study do not differ essentially from those described by other groups. Although the Brazilian population is usually the product of different ethnic groups, our results show that the frequency of each recurrent abnormality is similar to that found in populations without our degree of diverse ethnic composition. Hence, our results suggest that childhood ALL in Brazil has the same biological features as that in developed countries, supporting the use of similar treatment protocols. We can therefore expect to reach the same survival rates in the coming years, depending possibly on the efficacy of the support therapy and extent of social assistance.     

Intrahepatic Fat Content and COVID-19 Lockdown in Adults with NAFLD and Metabolic Syndrome

Background: COVID-19 lockdowns had a significant impact on people’s health, triggering levels of anxiety, perceived stress, and changes in food and nutritional status. Objectives: To assess the changes in dietary habits, metabolic syndrome (MetS) and liver parameters before and after the COVID-19 lockdown according to changes in intrahepatic fat content in adults with non-alcoholic fatty liver disease (NAFLD) and MetS. Design: Pre- and post-lockdown observation of the COVID-19 lockdown on fifty-nine 40–60-year-old participants with MetS and NAFLD, in a parallel group, randomised experiment intended to treat NAFLD. Methods: Anthropometrics, liver and MetS biochemical parameters, intrahepatic fat content by abdominal magnetic resonance imaging, and dietary assessment using a validated 148-item Food Frequency Questionnaire were collected pre-COVID-19 lockdown and post-lockdown. Results: COVID-19 lockdown led to negative changes in the liver of patients with NAFLD and MetS, with weight gain and increases in glycemia, ALT and intrahepatic fat content post lockdown. Participants with worsened liver status had low consumption of fibre, cheese, nuts and coffee, and high consumption of sweets and pastries. Participants who improved liver status ameliorated ALT values, waist circumference, and intrahepatic fat content, assessed by magnetic resonance imaging post-lockdown. Conclusions: The maintenance of healthy lifestyle habits is vital, especially for populations with NAFLD and MetS, to reduce unhealthy lifestyle patterns displayed during lockdown.     

Fundus autofluorescence imaging findings in retinal pigment epithelial tear

PURPOSE: Retinal pigment epithelial (RPE) tear is a clinical and angiographic entity, which usually occurs in association with pigment epithelial detachments (PED), in the context of neovascular age-related macular degeneration (ARMD). The recording of fundus autofluorescence (FAF) has been introduced as a technique of retinal imaging, allowing the in vivo assessment of the integrity of RPE. The authors describe the FAF imaging findings in a patient with RPE tear. METHODS: Observational case report. RESULTS: A 70-year-old woman developed RPE tear after the application of photodynamic therapy for choroidal neovascularization associated with PED. The diagnosis of the RPE tear was confirmed by fluorescein angiography (FA) and indocyanine green angiography (ICGA). FAF imaging revealed absence of autofluorescence at the area which was denuded of RPE, while at the area where the RPE was rolled, a heterogeneous signal of FAF was recorded. The intensity of the signal in that area was, on average, not different from the normal background FAF signal expected in an unaffected RPE/photoreceptor complex. CONCLUSIONS: The authors report the FAF imaging findings in a patient with RPE tear. These findings can be interpreted from the ability of FAF imaging to access in vivo the integrity of RPE, and correlate well with the histopathology of this clinical entity. FAF imaging, as a fast and noninvasive technique, may be a useful modality, alternative to FA and ICGA, in the diagnosis and evaluation of such cases. Moreover, it may contribute to a more detailed phenotyping of the various clinical pictures associated with neovascular ARMD.     

差示分光光度法测定制剂中硝苯啶的含量

利用硝苯啶溶液对光不稳定的性质,在波长350nm处测其光照前后的吸收度差值(△A),△A与硝苯啶乙醇溶液浓度在10～60μg/ml范围内呈线性关系。使用本法对硝苯啶片进行了含量测定,并对其类似物进行了干扰试验,排除了组分的干扰。该法的精密度日内为1.3%,日间为1.9%,平均回收率为99.96%。方法简便、快速,不需色谱等分离手段即可达到分析目的,专一性、重复性均较好,是分析硝苯啶制剂的一种新途径。     

Reorganization of thalamocortical connections in congenitally blind humans

Cross‐modal plasticity in blind individuals has been reported over the past decades showing that nonvisual information is carried and processed by “visual” brain structures. However, despite multiple efforts, the structural underpinnings of cross‐modal plasticity in congenitally blind individuals remain unclear. We mapped thalamocortical connectivity and assessed the integrity of white matter of 10 congenitally blind individuals and 10 sighted controls. We hypothesized an aberrant thalamocortical pattern of connectivity taking place in the absence of visual stimuli from birth as a potential mechanism of cross‐modal plasticity. In addition to the impaired microstructure of visual white matter bundles, we observed structural connectivity changes between the thalamus and occipital and temporal cortices. Specifically, the thalamic territory dedicated to connections with the occipital cortex was smaller and displayed weaker connectivity in congenitally blind individuals, whereas those connecting with the temporal cortex showed greater volume and increased connectivity. The abnormal pattern of thalamocortical connectivity included the lateral and medial geniculate nuclei and the pulvinar nucleus. For the first time in humans, a remapping of structural thalamocortical connections involving both unimodal and multimodal thalamic nuclei has been demonstrated, shedding light on the possible mechanisms of cross‐modal plasticity in humans. The present findings may help understand the functional adaptations commonly observed in congenitally blind individuals.     

Expression of fibrinogen receptors during activation and subsequent desensitization of human platelets by epinephrine

Epinephrine causes platelet aggregation and secretion by interacting with alpha 2-adrenergic receptors on the platelet surface. Platelet aggregation requires the binding of fibrinogen to a specific receptor on the membrane glycoprotein IIb-IIIa complex. Although the IIb-IIIa complex is identifiable on the surface of resting platelets, the fibrinogen receptor is expressed only after platelet activation. The current studies were designed to examine the effect of occupancy of platelet alpha 2-adrenergic receptors by epinephrine on the expression of fibrinogen receptors and on the aggregation of platelets. The ability of epinephrine to induce the expression of fibrinogen receptors was studied under two different conditions: acute stimulation (less than 1 min) and prolonged stimulation (50 to 90 min), the latter of which is associated with a reduction or "desensitization" of the platelet aggregation response. Expression of the fibrinogen receptor was monitored with 125I-fibrinogen as well as with 125I-PAC-1 (PAC-1), a monoclonal antibody that binds to the glycoprotein IIb-IIIa complex only after platelets are activated. Epinephrine caused an immediate increase in PAC-1 and fibrinogen binding that was dependent on occupancy of the alpha 2-receptor by epinephrine and on the presence of extracellular free Ca (KCa = 30 mumol/L). By itself, 1 mmol/L Mg was unable to support induction of the fibrinogen receptor by epinephrine. However, it did decrease the Ca requirement by about two orders of magnitude. Prolonged stimulation of unstirred platelets by epinephrine led to a 70% decrease in the aggregation response when the platelets were subsequently stirred. Despite their decreased aggregation response, desensitized platelets bound PAC-1 and fibrinogen normally, indicating that the loss of aggregation was not due simply to a decrease in fibrinogen receptor expression. Although desensitization was not affected by pretreatment of the platelets with aspirin, it was partially prevented when extracellular Ca was chelated by EDTA during the long incubation with epinephrine. These studies demonstrate that once platelet alpha 2-adrenergic receptors are occupied by epinephrine, extracellular Ca is involved in initiating the aggregation response by supporting the induction of the fibrinogen receptor and the binding of fibrinogen. Furthermore. Ca-dependent reactions subsequent to fibrinogen binding may be necessary for maximal platelet aggregation and are impaired when platelets become desensitized to epinephrine.     

Chlorambucil therapy in hairy cell leukemia: effects on lipid composition and lymphocyte subpopulations

Two patients with progressive hairy cell leukemia following splenectomy were treated with low-dose daily chlorambucil. Both had an objective hematologic response as determined by a return to normal hematocrit and platelet count. This was also reflected in the mononuclear cell fraction by the normalization of cholesterol content, cholesterol/phospholipid ratio, and the lymphocyte subpopulations. This article confirms previous reports on the efficacy of chlorambucil in this setting and describes some morphological, and biochemical concomitant events.     

The electrocardiogram in apical hypertrophic myocardiopathy. A case report with unique manifestations

We report the case of a 63-year-old female patient with apical hypertrophic cardiomyopathy, diagnosed by the presence of localized apical hypertrophy in the echocardiogram and a typical "spade like" left ventricular angiographic image, but with unique electrocardiographic features, characterized by chronic ST segment elevation, and T wave inversion, in the anterolateral leads. These changes were initially interpreted as a manifestation of acute ischemic heart disease. Chronic ST segment elevation has been occasionally described in patients with hypertrophic cardiomyopathy complicated with apical necrosis and aneurysm formation, but not in uncomplicated cases of apical hypertrophic cardiomyopathy. Its knowledge by the physician could allow avoidance of problems of differential diagnosis with more frequent heart diseases, especially acute atherosclerotic ischaemic heart disease.