Thymic cysts in mediastinal Hodgkin disease

Three cases of proved thymic cysts associated with mediastinal Hodgkin disease are presented. Two illustrate regression of lymphoma with chemotherapy but persistence of thymic cysts. The third case demonstrates a thymic cyst in untreated Hodgkin disease. These cases suggest that such cysts are probably neither coincidental with nor a consequence of therapy but are probably related to initial thymic involvement by Hodgkin disease.     

The binding and processing of monoclonal human IgG1 by cells of a human macrophage-like cell line (U937)

The goal of these experiments was to assess the relationship between the binding and processing of IgG by Fc-receptor-bearing cells. Cells of the U937 human macrophage-like cell line were incubated with 125I- labeled monomers, dimers, oligomers (composed of 2-4 IgG1 subunits), and HP (heavy polymers composed of 5 or more subunits per polymer) of monoclonal human IgG1 in vitro. Binding was assessed by spinning cells through a layer of phthalate oils. Internalization of IgG1 was assessed by quantitating residual binding to cells after surface-bound IgG was removed by a brief treatment with a solution containing 0.25 M acetic acid and 0.5 M sodium chloride. Catabolism was assessed by measuring the release of radioactive fragments of IgG1, which were not precipitated by 10% trichloroacetic acid. Unstimulated U937 bound about 10,000 molecules per cell of IgG1 monomer, with an equilibrium binding constant (Ka) of 5 X 10(8) M-1. After stimulation with a conditioned medium in vitro, binding per cell was increased 3-7--fold, and the Ka was decreased 2-4--fold. Both unstimulated and stimulated cells internalized and catabolized labeled IgG1 HP, but stimulated cells internalized and digested much more IgG1 HP per cell than unstimulated cells. Both monomers and dimers of IgG1 were internalized and degraded very slowly by stimulated cells, even though both preparations readily bound to cells. In contrast, oligomers and (to an even greater extent) IgG1 HP were internalized and degraded much more rapidly. Internalization of IgG1 HP was markedly inhibited by incubation at 4 degrees C, but not by incubation with a variety of metabolic inhibitors. Catabolism was inhibited by chloroquine and monensin (inhibitors of lysosomal acidification) and by cytochalasin (an inhibitor of microfilament polymerization). Binding to the surface of cells was not markedly inhibited by any agent tested. The capacity of cells to bind labeled IgG1 was markedly reduced by prior incubation in the presence of unlabeled IgG1. This reduction was in part due to the steric blockade of receptors caused by the avid, but reversible, binding of IgG1. In addition, IgG1 oligomers or HP (but not IgG1 monomers or dimers) also caused an irreversible reduction in the number of Fc receptors by a process analogous to receptor down-regulation, as observed in other receptor--ligand systems.     

Calcium absorption from corn tortilla is relatively high and is dependent upon calcium content and liming in Mexican women

Corn tortillas are the staple food of Mexico. During their preparation, calcium is added to the tortillas; therefore, tortillas are the main source of calcium for a large proportion of the population. The bioavailability of calcium from lime-treated tortillas in humans is not known. The objectives of the present study were to determine calcium absorption from corn tortilla, to determine the effect of lime treatment on calcium absorption from corn tortilla, and to compare calcium absorption from tortilla prepared with a commercial corn flour and tortillas prepared with the traditional lime treatment at home. Nonpregnant, nonlactating women (n = 9) were administered 3 different treatments: 1) 180 g of corn tortilla prepared from corn flour with no lime treatment (CF), 2) 180 g of corn tortilla prepared from lime-treated commercial corn flour (LTCCF), or 3) 180 g of corn tortillas prepared from lime-treated home-prepared corn flour (LTHCF). Calcium absorption was measured using an established dual-tracer stable isotope technique. Calcium absorption of CF, LTCCF, and LTHCF was (mean +/- SD): 44 +/- 3.2, 32 +/- 4.4, and 30 +/- 2.4%, respectively; the fractional calcium absorption from CF differed from that of either LTCCF or LTHCF (P < 0.01). The total amount of calcium absorbed per treatment was higher in LTHCF (98.10 mg +/- 21.7) than in LTCCF (59.9 mg +/- 23.7, P < 0.001) and CF (3.78 mg +/- 0.9, P < 0.0.001). In conclusion, calcium absorption from corn tortillas is high and dependent on calcium concentration. The addition of calcium during lime treatment increases calcium concentration and total calcium absorption.     

Prevalance of proteinuria in Mexico: a conjunctive consolidation approach with other cardiovascular risk factors: the Mexican Health Survey 2000

BACKGROUND: A number of cross-sectional or serial studies have demonstrated the clinical impact of microproteinuria and macroproteinuria by identifying individuals at risk of both end-stage renal disease and major cardiovascular events. This study focused on the prevalence of proteinuria in Mexico and its relationship with other cardiovascular risk factors such as hypertension, type 2 diabetes mellitus, body mass index, smoking, age, and gender. METHODS: The prevalence of proteinuria in Mexico was obtained from the probabilistic cross-sectional national health survey performed in the year 2000. The proportion of urine dipstick samples that tested positive for protein (defined as > or =1+) in adults from 20 to 69 years of age was determined. The analysis was performed using both algebraic and multicategorical models. Potential interactions between proteinuria and other major cardiovascular risk factors were investigated. RESULTS: A total of 46,523 adult survey participants were included in the analysis. In the general population, 9.2% had proteinuria. By univariate, multivariate, and multicategorical analysis, hypertension, diabetes, obesity, and age were strongly associated with the prevalence of proteinuria (P < 0.001). However, in Mexico, the specific distribution of age groups demonstrated that the absolute number of patients without hypertension that had proteinuria is not irrelevant. To identify 1 case of proteinuria, one would need to screen 3 persons with diabetes mellitus, 5 patients with hypertension without diabetes, or 6 persons over the age of 55 years. When proteinuria is present, the probability of having a noncommunicable chronic disease or other major cardiovascular risk factor is more than 85%. CONCLUSION: Proteinuria is prevalent. When considered together, dipstick-positive proteinuria, blood pressure level, body mass index > or =30 m(2)/kg, and abnormal fasting blood glucose measured on a single occasion identifies different segments of the population. Studies such as this may be a suitable initial clinical approach to general population screening for renal and cardiovascular risk stratification.     

The influence of motion coherence manipulations on the synchronization level of a perception-action task

The present experiment was conducted to examine the integration of the motion coherence paradigm in a synchronization task. Random-dot kinematograms were used to generate a pattern of oscillating dots representing four different coherence levels (10%, 30%, 50% and 100%) and one target-alone condition. The participants had to synchronize their arm with the coherently moving dots according to two different synchronization modes (in-phase and anti-phase). The results revealed a substantial performance decline when the target/noise ratio dropped under the critical threshold situated around the 30% coherence level, albeit independent of the synchronization mode. In general, these findings highlighted the impact of the perception of motion based on the level of motion coherence in the visual signal on the synchronization behavior in a perception-action setting.     

Atrial septal defect in adults > or =40 years old: negative impact of low arterial oxygen saturation

BACKGROUND: Although good prognosis and clinical long-term outcome have been commonly reported in minimally symptomatic adult patients with ASD, this information has been based on studies with a relatively small number of adult patients. We studied unoperated patients aged over 40 years to define the patterns of presentation, anatomical characteristics, outcome and predictive factors for free-event survival of major cardiovascular and pulmonary events. METHODS AND RESULTS: Two-hundred survivors of atrial septal defect aged over 40-yr attended from 1985 to 1998 were reviewed and followed-up from 1.6 to 22 years. Patients were classified in three groups according to age at entry: Group 1, between 40 and 49; Group 2; 50 and 59; and Group 3, > or =60 years old. The mean age at presentation was 48.8+/-9.2 years, and the most common clinical presentations were arrhythmia and dyspnea (51.4%). There were 37 (18.5%) events: 7 heart failure-related, 5 sudden death, 13 severe pulmonary infections, 5 embolisms, and 4 strokes. According to Cox's regression analysis, predictors of primary end point included age group at presentation (hazard ratio 1.71, 95% confidence limits 1.16 to 2.54), and either pulmonary hypertension (mean pulmonary pressure >35 mmHg; hazard ratio=0.65 (4.6, confidence limits 2.2 to 9.5) or, arterial oxygen saturation <80% (hazard ratio 1.71, 95% confidence limits 1.16 to 2.54). CONCLUSIONS: This study supports that long term outcome of patients aged >40 years with unoperated ASD is importantly determined by the mPAP (>35 mmHg), SaO2% (_80) and the age at diagnosis. Nevertheless we identified an inverse association between the mPAP level and SaO2% (interaction). The event-free survival expectancy may be estimated using the age at diagnosis and either SaO2% or mPAP. This prognostic stratification based on pathophysiological principles, may help in making decisions for therapeutic interventions. SaO2% should always be measured as a part of the initial clinical approach of those patients with atrial septal defect aged over 40 years.     

Association of decreased quality of life and erectile dysfunction in hemodialysis patients

BACKGROUND: Quality of life in hemodialysis patients has been associated with treatment outcomes. We explored the impact of erectile dysfunction on quality of life in a cohort of hemodialysis subjects. METHODS: A random sample of 302 Philadelphia area hemodialysis (HD) subjects was enrolled using a cross-sectional design. Subjects completed a self-administered questionnaire including items on sexual function, past medical history, and quality of life. Linear regression (accounting for sampling design by weighted estimation methods) was used to examine the associations between various measures of quality of life (the dependent variables) and erectile dysfunction (ED) and other variables (the predictor variables). RESULTS: We found the emotional domains of the SF-36, a multi-purpose, short-form health survey with 36 questions, to be more profoundly associated with ED than the physical domains. Using the physical and mental components of the SF-12, a new 12-item short form health survey as predictors of ED, only the mental composite score (MCS) was statistically significant after adjusting for age and diabetes (P = 0.008). Subjects with ED had significantly lower quality of life mean scores. In particular, ED was associated with poorer social interaction (mean score difference, -10.3, adjusted P < 0.001), decreased emotional well-being (-12.9, adjusted P = 0.005), more role limitations due to emotional problems (-22.9, adjusted P = 0.01), and poorer social function (-17.8, P = 0.001). CONCLUSION: Recent advances in therapies for ED warrant that the diagnosis and treatment of erectile dysfunction be included in the global health assessment by the nephrologists and primary care providers of patients with renal insufficiency, as it may improve the quality of life of patients.