Functional magnetic resonance imaging of human hypothalamic responses to sweet taste and calories

BACKGROUND: Evidence exists that beverages do not trigger appropriate anticipatory physiologic responses, such as cephalic phase insulin release. Therefore, it is of interest to elucidate the food properties necessary for triggering adaptive responses. Previously, we found a prolonged dose-dependent decrease in the hypothalamic functional magnetic resonance imaging signal after ingestion of a glucose solution. OBJECTIVES: The aims of the present study were to measure the effects of sweet taste and energy content on the hypothalamic response to glucose ingestion and to measure the concomitant changes in blood glucose and insulin concentrations. DESIGN: Five healthy, normal-weight men participated in a randomized crossover design trial. The subjects were scanned 4 times for 37 min on separate days with functional magnetic resonance imaging. After 7 min, they ingested 1 of the following 4 stimuli (300 mL of each): water (control), a glucose solution, an aspartame (sweet taste) solution, or a maltodextrin (nonsweet carbohydrate) solution. RESULTS: Glucose ingestion resulted in a prolonged and significant signal decrease in the upper hypothalamus (P < 0.05). Water, aspartame, and maltodextrin had no such effect. Glucose and maltodextrin ingestions resulted in similar increases in blood glucose and insulin concentrations. However, only glucose triggered an early rise in insulin concentrations. Aspartame did not trigger any insulin response. CONCLUSIONS: Our findings suggest that both sweet taste and energy content are required for a hypothalamic response. The combination of sweet taste and energy content could be crucial in triggering adaptive responses to sweetened beverages.     

Food acceptability in field studies with US army men and women: relationship with food intake and food choice after repeated exposures

Laboratory data with single exposures showed that palatability has a positive relationship with food intake. The question addressed in this study is whether this relationship also holds over repeated exposures in non-laboratory contexts in more natural environments. The data were collected in four field studies, lasting 4-11 days with 307 US Army men and 119 Army women, and comprised 5791 main meals and 8831 snacks in total. Acceptability was rated on the nine point hedonic scale, and intake was registered in units of 1/4, 1/2, 3/4, or 1 or more times of the provided portion size. Correlation coefficients between individual acceptability ratings and intakes varied from 0.22 to 0.62 for the main meals (n=193-2267), and between 0.13 and 0.56 for the snacks (n=304-2967). The likelihood of choosing a meal for the second time was positively related to the acceptability rating of the meal when it was consumed for the first time. The results reinforce the importance of liking in food choice and food intake/choice behavior. However, the magnitude of the correlation coefficients between acceptability ratings and food intake suggest that environmental factors also have an important role in determining intake and choice.     

Prognostic variables for high titres in a fluorescent antibody test to diagnose tuberculosis

SETTING: The four hospitals and a tuberculosis clinic in the province of Zeeland, The Netherlands. OBJECTIVE: To assess the usefulness of PPD antibody measurement in the diagnosis of tuberculosis in patients admitted to hospital. PATIENTS AND METHODS: Sixty-one patients presenting with active tuberculosis, and 215 control patients were included in the study. Initial serum PPD antibody titres were determined with a macrophage uptake Fluorescent antibody test (MuFat) to construct a discrimination model between Tuberculosis (TB) and non-TB. We also retrospectively collected clinical parameters of the TB patients at presentation. Univariate and multivariate logistic regression are used to identify variables predicting high antibody titres. RESULTS: In TB patients, the presence of clinical symptoms (OR=10.63) and the presence of at least two concurrent non-lymph node disease localizations outside thorax and abdomen (OR=13.94) are necessary and sufficient to predict high titres. The logistic model shows a significant contribution of the 2log (titre) to the discrimination between TB and non-TB patients. At a cut-off value of 128, a specificity, sensitivity, and positive predictive and negative predictive values of 97%, 39%, 80% and 85%, respectively, are calculated in the study cohort. CONCLUSION: Our data suggest an application of the test at high cut-off values for timely diagnosis of difficult-to-diagnose TB patients. The results of this retrospective study will have to be confirmed in further prospective studies.     

Validation of ECG indices of ventricular repolarization heterogeneity: a computer simulation study

INTRODUCTION: Repolarization heterogeneity (RH) is functionally linked to dispersion in refractoriness and to arrhythmogenicity. In the current study, we validate several proposed electrocardiogram (ECG) indices for RH: T-wave amplitude, -area, -complexity, and -symmetry ratio, QT dispersion, and the Tapex-end interval (the latter being an index of transmural dispersion of the repolarization (TDR)). METHODS AND RESULTS: We used ECGSIM, a mathematical simulation model of ECG genesis in a human thorax, and varied global RH by increasing the standard deviation (SD) of the repolarization instants from 20 (default) to 70 msec in steps of 10 msec. T-wave amplitude, -area, -symmetry, and Tapex-end depended linearly on SD. T-wave amplitude increased from 275 +/- 173 to 881 +/- 456 muV, T-wave area from 34 x 10(3)+/- 21 x 10(3) to 141 x 10(3)+/- 58 x 10(3)muV msec, T-wave symmetry decreased from 1.55 +/- 0.11 to 1.06 +/- 0.23, and Tapex-end increased from 84 +/- 17 to 171 +/- 52 msec. T-wave complexity increased initially but saturated at SD = 50 msec. QT dispersion increased modestly until SD = 40 msec and more rapidly for higher values of SD. TDR increased linearly with SD. Tapex-end increased linearly with TDR, but overestimated it. CONCLUSION: T-wave complexity did not discriminate between differences in larger RH values. QT dispersion had low sensitivity in the transitional zone between normal and abnormal RH. In conclusion, T-wave amplitude, -area, -symmetry, and, with some limitations, Tapex-end and T-wave complexity reliably reflect changes in RH.     

Staphylococcus aureus relapsing bacteremia originating from endovascular thrombi

Two infants presented with a recurrent methicillin-susceptible Staphylococcus aureus bacteremia occurring >2 months after the initial bacteremia. In both patients, clonal identity of the successive Staphylococcus aureus isolates, confirmed by pulsed field gel electrophoresis, pointed to relapsing bacteremia. Ultrasonographically proved persistence of an endovascular thrombus was considered as the focus of persistent infection in each case.     

Amyloid β 38, 40, and 42 species in cerebrospinal fluid: More of the same?

Various C-terminally truncated amyloid beta peptides (Abeta) are linked to Alzheimer's disease (AD) pathogenesis. Cerebrospinal fluid (CSF) concentrations of Abeta38, Abeta40, and Abeta42 were measured by enzyme-linked immunosorbent assay in 30 patients with AD and 26 control subjects. CSF Abeta42 levels was decreased in patients with AD, whereas CSF Abeta38 and Abeta40 levels were similar in patients with AD and control subjects. All three Abeta peptides were interrelated, particularly CSF Abeta38 and Abeta40. Diagnostic accuracy of CSF Abeta42 concentrations was not improved by applying the ratios of CSF Abeta42 to Abeta38 or Abeta40.     

Radical radiotherapy compared with surgery for advanced squamous cell carcinoma of the base of tongue

PURPOSE: This study reports on T3/T4 base of tongue (BOT) tumors treated at the Erasmus MC (Rotterdam) with external beam radiotherapy (EBRT) and brachytherapy (BT). Local control, survival, and functional outcome are compared to results obtained in similar patients treated at the Vrije University Medical Center (VUMC, Amsterdam) by surgery and postoperative RT (PORT). METHODS AND MATERIALS: At Rotterdam 46/2 Gy was given to the primary and bilateral neck, followed by an implant using low-dose-rate (LDR 24-35 Gy; median 27 Gy), or fractionated high-dose-rate (fr. HDR 20-28 Gy; median 24 Gy). A neck dissection (ND) was performed in case of N+ disease. 67% of BOT tumors had a T4 cancer. At Amsterdam surgery (S) followed by PORT 40-70 Gy (median 60 Gy) was performed; 26% BOT tumors were T4. Sex, age and nodal distribution were similar. Actuarial local control and survival were computed. Performance Status Scale (PSS) scores were established. Xerostomis was determined on visual analog scales (VAS). RESULTS: Local failure at 5-years was 37% (Rotterdam) vs. 9% (Amsterdam) (p < 0.01). The overall survival was not significantly different (median 2.5 years vs. 2.9 years, respectively [p = 0.47]). The PSS favored brachytherapy. Both groups were equally affected by xerostomia. CONCLUSIONS: The 5-year local control was 65% with EBRT and BT. This result is strongly affected by 4 patients with residual disease after implantation. The Rotterdam patients had more advanced BOT tumors (67% vs. 26% T4), explaining the higher local failure rate. Given the organ preservation properties of radiotherapy-only and the better PSS scores, the jury is still out on the optimal treatment for BOT tumors.