Differential cingulate and caudate activation following unexpected nonrewarding stimuli

This study examined the effects of varying the predictability of nonrewarding events on behavior and neural activation using a rapid mixed-trial functional magnetic resonance imagery (fMRI) design. Twelve adult subjects were scanned with echo planar imaging during performance of a visual detection task where the probability of events (target and nontarget) varied. This task included expected and unexpected nonrewarding events (expected target, unexpected nontarget, and omission of target) in a design that closely parallels studies of dopamine function and reward processing in the alert monkey. We predicted that activation in dopamine-rich areas of the forebrain would behave like the animal literature shows that dopamine neurons in the midbrain behave. Specifically, we predicted increased activity in these regions when an unexpected event occurred and decreased activity when an expected event was omitted. Two main regions, the anterior cingulate and dorsal striatum, showed this pattern. The response in these regions was distinguished by enhanced anterior cingulate activity following the occurrence of an unexpected event and greater suppression of caudate activity following the omission of an expected event. These results suggest that neural activity within specific dopamine-rich brain regions can be modulated by violations in the expectation of nonrewarding events and that the direction of the modulation depends on the nature of the violations.     

Interdialytic weight gain and pulmonary membrane diffusing capacity in patients on hemodialysis

Background: Measurement of pulmonary diffusion capacity for carbon monoxide (DLCO) may be useful for assessing disease affecting the alveolar-capillary bed or the pulmonary vasculature. It was reported that hemodialysis (HD) therapy causes DLCO reduction via decrease of pulmonary capillary blood volume components. The aim of the study was to evaluate the effect of interdialytic weight gain on pulmonary function and especially DLCO. We further determined whether intravascular volume status, assessed by inferior vena cava diameter (IVCD) contributes to DLCO in patients on HD. Methods: Routine pulmonary function testing including forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), FEV1/FVC, forced mid-expiratory flow rate (FEF_25–75), DLCO IVCD index and other echocardiographic parameters were evaluated in 20 patients (mean age 48.6 ± 18.3 years, mean dialysis duration 17.4 ± 19.2 months) on chronic HD, 1 hour after HD and after an interdialytic period (1 hour before HD therapy). Single-breath DLCO measurements were corrected for hemoglobin concentration (cDLCO). Results: Routine pulmonary function tests (spirometry) showed no significant changes in FEV1, FVC and FEF_25–75 whereas a statistically significant fall in FEV/FVC was found. At the end of the interdialytic period a statistically significant increase in weight, IVCD index, left ventriculer diastolic diameter (LVDD), and diastolic blood pressure (DBP) were observed (P < 0.05). Using the single-breath DLCO, we found unchanged cDLCO at the end of the interdialytic period. There was no correlation of cDLCO with increases in weight, DBP, IVCD index, LVDD (P > 0.05). Conclusion: The accumulation of body water between dialyses has no significant influence on DLCO.     

99mTc-depreotide scintigraphy in the evaluation of indeterminate pulmonary lesions: clinical experience

Indeterminate lung nodules (LN) constitute a clinical problem of increasing frequency that requires an effective diagnostic approach. This study evaluates the contribution of 99mTc-depreotide scintigraphy in the management of such patients. Forty (40) patients (27 males/13 females) 29 to 82 years old (61 +/- 12) with lung nodules/masses of indeterminate origin on computed tomography (CT) images were injected with 99mTc-depreotide and underwent thoracic tomography (single photon emission computed tomography) 2 and 4-4.5 hours later. All parenchymal lesions (50) identified by CT were scored as negative or positive as to the uptake of 99mTc-depreotide. Positive images were also evaluated semiquantitatively. Thirty (30) of 31 malignant lesions were positive (97% sensitivity) and 12 out of 19 benign lesions were negative (63% specificity), with positive images obtained in benign processes such as inflammation/infection and bronchiectasis. Semiquantitative analysis showed a statistically significant difference between benign and malignant positive lesions on the late images, and may play a complementary role in interpretation. 99mTc-depreotide was a useful noninvasive tool in the evaluation of patients with LN, allowing for the exclusion of malignancy with great confidence, due to its high sensitivity. Because of moderate specificity, a positive test is best valued together with clinical and radiological features.     

Effect of different doses of progestin on uterine leiomyomas in postmenopausal women

OBJECTIVE(S): To evaluate the effects of two doses of medroxyprogesterone acetate (MPA) on uterine leiomyoma sizes and on uterine bleeding pattern in postmenopausal women treated with oral hormone replacement therapy (HRT). STUDY DESIGN: Thirty natural postmenopausal women affected by uterine leiomyomas were enrolled and treated with oral micronized estradiol (E(2)) at dose of 2 mg per day, and randomized to receive in association MPA at dose of 2.5 mg daily (group A) or of 5 mg daily (group B). At the beginning of the study and after 1 year of treatment, uterine leiomyomata dimensions were measured using transvaginal ultrasonography (TV-USG). The subjects were instructed to note on a daily dairy the number and severity of abnormal uterine bleeding (AUB) episodes. RESULTS: After 1 year of therapy, a significant changes in mean uterine leiomyomas size was observed in the group treated with higher dose of MPA. No significant differences in uterine bleeding were detected between the two groups. CONCLUSION(S): In postmenopausal women with uterine leiomyomas, it is necessary to use the minimal efficacious dose of progestin during HRT because of a higher risk to increase the tumors dimensions.     

Increased Diffusion in the Brain of Professional Boxers: A Preclinical Sign of Traumatic Brain Injury?

BACKGROUND AND PURPOSE: Professional boxing is associated with chronic, repetitive head blows that may cause brain injuries. Diffusion-weighted imaging is sensitive to microscopic changes and may be a useful tool to quantify the microstructural integrity of the brain. In this study, we sought to quantify microscopic alterations associated with chronic traumatic brain injury in professional boxers. METHODS: MR and diffusion-weighted imaging were performed in 24 boxers and in 14 age- and sex-matched control subjects with no history of head trauma. Using distribution analysis, the average diffusion constant of the entire brain (BD(av)) and diffusion distribution width (sigma) were calculated for each subject; findings in professional boxers were compared with those of control subjects. In the boxer group, correlations between diffusion changes and boxing history and diffusion changes and MR imaging findings were assessed. RESULTS: The measured diffusion values in the boxer group were significantly higher than those measured in the control group (BD(av), P <.0001; sigma, P <.01). In the boxer group, a robust correlation was found between increased BD(av) and frequency of hospitalization for boxing injuries (r = 0.654, P <.05). The most common MR finding in the boxer group was volume loss inappropriate to age followed by cavum septum pellucidum, subcortical white matter disease, and periventricular white matter disease. CONCLUSION: Boxers had higher diffusion constants than those in control subjects. Our data suggest that microstructural damage of the brain associated with chronic traumatic brain injury may elevate whole-brain diffusion. This global elevation can exist even when routine MR findings are normal.     

Diabetes mellitus and atypical antipsychotics

Schizophrenic patients present a higher risk for the development of hyperglycemic disorder and the use of antipsychotic drugs seems to increase the risk of diabetes mellitus. The present review concerns the relation between atypical antipsychotic drugs and the risk of developing diabetes mellitus. A Medline and Webofscience search was performed by using the terms "Hyperglycemia", "Diabetes Mellitus" and "Antipsychotic Agents", to identify original papers and reviews published between 1997 and september 2002. It is concluded that there is a higher risk of glycemic disorders in the population of patients treated by antipsychotic drugs. Dietetic measures and attention to risk factors should be taken into account during the treatment of psychotic patients.     

Effect of clozapine on serum leptin,insulin levels,and body weight and composition in patients with schizophrenia

OBJECTIVE: Weight gain frequently occurs during treatment with clozapine. However, the pathophysiology of clozapine-induced weight gain remains unclear. The aim of this study was to investigate the influence of clozapine on hormones leptin and insulin in relation to body weight and composition measures to determine their contribution to clozapine-induced weight gain. METHOD: Data are reported on 19 patients with schizophrenia (11 women and 8 men) who completed 10 weeks of treatment with clozapine. Insulin levels, weight measurements, body mass index (BMI), and body composition measurements were evaluated at baseline and at the end of treatment. Leptin levels were assessed at baseline and after 4 and 10 weeks of treatment. Analysis of variance with repeated measures was used to evaluate changes in weight, body composition measures, leptin, and insulin. The Pearson correlations were used to assess the relationships between changes in hormone levels and weight along with body composition measurements. The correlations of change in Positive and Negative Syndrome Scale (PANSS) score with changes in hormone levels, weight gain and body composition measures were evaluated with Pearson correlations. RESULTS: Leptin and insulin levels did not show any significant alterations across time. The use of clozapine was associated with significant increases in BMI (F=19.8, P<.001), lean muscle mass (F=8.2, P=.01), and fat mass (F=15.4, P=.001), while total body fluid percentage (F=4.1, P=.05) significantly decreased. Improvement in PANSS scores was not correlated to change in leptin, insulin, weight, BMI, or body composition measurements. The change in leptin levels was correlated to change in body fat mass. CONCLUSION: The role of leptin in weight gain induced by clozapine might be a regulatory mechanism rather than being etiologic.     

Comparison of ranitidine bismuth citrate, tetracycline and metronidazole with ranitidine bismuth citrate and azithromycin for the eradication of Helicobacter pylori in patients resistant to PPI based triple therapy.

BACKGROUND/AIMS: Helicobacter pylori is the most common infectious disease all over the world. Ten to twenty percent of the patients remain infected despite treatment with proton pump inhibitors (PPIs), amoxicillin and clarithromycin. We compared PPI, bismuth, tetracycline and metronidazole with ranitidine bismuth citrate, tetracycline and metronidazole in cases resistant to PPIs-based triple therapies. METHODS: The study included 52 patients who underwent a triple therapy with PPI, clarithromycin and amoxicillin for 14 days between September 2001 and December 2002, and were found to be resistant to the therapy. They were randomized to take ranitidine bismuth citrate (Rb) 400 mg twice a day, tetracycline (T) 1 g twice a day and metronidazole (M) 500 mg three times a day for 14 days (RbTM), or ranitidine bismuth citrate (Rb) 400 mg twice a day for 14 days and azithromycin (A) 500 mg once a day for 7 days (RbA). Four weeks after the treatment, endoscopies were repeated, and patients were assessed with respect to changes in symptoms. When H. pylori was negative on histological analysis and urease test, eradication was achieved. RESULTS: A total of 52 patients, 32 females and 20 males with a mean age of 49+/-12 years, were included in the study. Eradication was achieved in 15 (28%) out of 52 patients in total. There was a significant difference between RbA and RbTM groups (p=0.01). In fact, H. pylori was eradicated in 3 (12%) out of 25 patients in the RbA group, whereas it was eradicated in 12 (44.4%) out of 27 patients in the RbTM group. Symptom scores significantly improved in both groups after the treatment, though there was not a significant difference between the groups (p=0.705). CONCLUSIONS: Triple therapy including azithromycin does not seem to be a good choice in cases resistant to the first line therapies; however, a similarly lower rate of eradication was achieved with the quadruple therapy proposed. Therefore, different treatment schemes should be applied in resistant patients, and further studies are needed as well.