Effect of carbohydrate ingestion on exercise endurance and metabolism after a 1-day fast

Fasting before an exercise event has been demonstrated to decrease endurance. The purpose of this study was to investigate whether this decrement in performance after fasting could be reversed by ingestion of a carbohydrate solution before and during exercise. Nine fit male subjects ran to exhaustion at approximately 70% VO2max in two counterbalanced trials. The subjects were fasted for 21 h before both trials, and the trials were arranged so that the subjects ingested either a carbohydrate (CHO) or placebo (PL) solution. Although ratings of perceived exertion were significantly lower in the CHO trial, there were no differences in endurance time to exhaustion in the two trials (102 +/- 8 min in the PL trial and 106 +/- 8 min in the CHO trial). There were no differences between trials for the VO2, heart rate, and blood lactate concentrations. As expected, the blood glucose and insulin concentrations were higher in the CHO trial. The respiratory exchange ratio was significantly higher in the CHO trial at 40 min of exercise and tended to be higher at all other times, suggesting a greater reliance on carbohydrate and less on fat as an energy source. This seemed to be confirmed by the significantly lower plasma glycerol concentration, which suggested less fat mobilization in the CHO trial. Ingestion of a glucose polymer solution increased carbohydrate utilization in fasted subjects, but exercise performance was not improved.     

Detection of polyglutamine expansion in a new acidic protein: a candidate for childhood onset schizophrenia?

Polyglutamine expansion (PGE) encoded by a CAG repeat underlies eight inherited neurodegenerative diseases, among which is Huntington's disease. CAG expansion has also been reported in schizophrenia, suggesting a role for PGE. To investigate the potential role of PGE as a candidate for schizophrenia, we searched for PGE in nuclear families comprising a patient affected by childhood onset schizophrenia (COS, a rare and severe form of the disease) as a variation of the candidate gene approach for identifying susceptibility genes. We tested lymphoblastoid cell lines from COS patients (n = 32) by Western blot analysis with 1C2, a monoclonal antibody that specifically recognizes long polyglutamines. Eight of 11 unrelated black American COS patients showed a 60-kDa (approximately) band indicative of PGE. A strong 60-kDa band (suggestive of a large PGE) was detected in two of the eight positive patients. A weaker 60-kDa band (suggestive of a smaller and non pathogenic PGE) was detected in some unaffected parents or sibs of these two COS patients, and in six other black American COS patients. The strong and weak PGE signals were found to correspond to two different proteins. Unrelated black Americans unaffected by COS (n = 38) were negative for the strong 60-kDa PGE signal. Healthy white Americans (n = 53) were negative for both the strong and weak 60-kDa PGE signals. Two-dimensional gel analysis suggested that the strong PGE signal corresponds to an acidic (pI 4 approximately) protein and resulted in a more precise estimation (52-57 kDa) of its relative mass. This protein appeared to be not represented in Genbank, as suggested by the exclusion of several candidate CAG repeats. Our data suggest that this acidic protein might be a candidate for COS.     

Revised curriculum on cardiothoracic radiology for diagnostic radiology residency with goals and objectives related to general competencies

This document is a revision of a previously published cardiothoracic curriculum for diagnostic radiology residency, and reflects interval changes in the clinical practice of cardiothoracic radiology and changes in the Accreditation Council for Graduate Medical Education (ACGME) requirements for diagnostic radiology training programs. The revised ACGME Program Requirements for Residency Education in Diagnostic Radiology went into effect December 2003.     

Myocardial depressant effects of sodium acetate

Sodium acetate produced a direct, dose-related decrease in myocardial contractile force in the dog and isolated rabbit papillary muscle. In the dog, there was also a decrease in blood pressure which was attributed primarily to the fall in contractile force. However, sodium acetate was found to have weak vasodilator properties as shown by the decreases in hind-limb perfusion pressure.     

Modulation of CaM kinase II activity is coincident with induction of status epilepticus in the rat pilocarpine model

PURPOSE: This study was conducted to characterize the early cellular changes in CaM kinase II activity that occur during the induction of status epilepticus (SE). METHODS: The pilocarpine model of SE was characterized both behaviorally and electrographically. At specific time points after the first discrete seizure, specific brain regions were isolated for biochemical study. Phosphate incorporation into a CaM kinase II-specific substrate, autocamtide III, was used to determine kinase activity. RESULTS: After the development of SE, the data show an immediate inhibition of both cortical and hippocampal CaM kinase II activity in homogenate, but a delayed inhibition in synaptic kinase activity. The maintenance of synaptic kinase activity was due to a translocation of CaM kinase II protein to the synapse. However, despite the translocation of functional kinase, CaM kinase II activity was not maintained, membrane potential was not restored, and the newly translocated CaM kinase II did not terminate the SE event. Unlike the homogenate samples, in the crude synaptoplasmic membrane (SPM) subcellular fractions, a positive correlation is found between the duration of SE and the inhibition of CaM kinase II activity in both the cortex and hippocampus. CONCLUSIONS: The data support the hypothesis that alterations of CaM kinase II activity are involved in the early events of SE pathology.     

Optimal reference mammography: a comparison of mammograms obtained 1 and 2 years before the present examination

OBJECTIVE: We assessed and compared the benefit of using images acquired 1 year or 2 years previously during mammography interpretations. MATERIALS AND METHODS: Eleven radiologists and one resident reviewed 128 cases three times: once without prior mammograms for comparison, once with mammograms from the most recent (1 year) examination, and once with mammograms acquired 2 years previously. They were asked to determine whether the patient should be recalled for additional procedures. Performances under the three conditions were compared. RESULTS: Radiologists were significantly more accurate (p < 0.001) when comparison mammograms (obtained 1 or 2 years previously) were available. Although sensitivity was not significantly affected between the availability of mammograms from 1 or 2 years earlier (p > 0.10), the specificity was. Specificity using mammograms from the latest examination (obtained 1 year previously) as a reference was significantly better (p = 0.03) than specificity using mammograms obtained 2 years previously. CONCLUSION: Comparison mammograms are important for accurate diagnosis-in particular, for increasing specificity. The latest prior examination seems to be the optimal one for this purpose.     

Effects of socioeconomic status on the obesity knowledge of adolescents from six Latin American cities

OBJECTIVE: To examine the effects of socioeconomic status (SES) on the obesity knowledge of adolescents in six Latin American cities. DESIGN: Data were collected using an anonymous, self-administered questionnaire consisting of demographic questions and a 25-item multiple-choice obesity knowledge test. Test items were clustered under five topics: the fat and calorie content of foods and beverages; weight loss methods; energy expenditure; food preparation methods; and the relationship between obesity and health. SUBJECTS: A total of 1272 ninth grade students from higher and lower SES families were recruited at schools in Buenos Aires, Argentina (n=195); Guatemala City, Guatemala (n=212); Havana, Cuba (n=213); Lima, Peru (n=218); Panama City, Panama (n=195); and Santiago, Chile (n=239). RESULTS: Mean test scores reflected a low level of obesity knowledge among adolescents from higher and lower SES groups in all six cities. Nevertheless, a trend for higher scores emerged in favor of adolescents from wealthier families. This income effect persisted after controlling for gender and weight status. The weakest knowledge areas among youth from the higher SES groups were food preparation methods and the relationship between obesity and health while those for adolescents from the lower SES groups were the fat and calorie content of foods and beverages and the relationship between obesity and health. Classroom instruction about obesity was generally more available to students from the higher SES groups. The majority of adolescents from both SES groups were interested in learning more about weight loss methods, energy expenditure, and the fat and calorie content of foods and beverages. The topic of least interest was the relationship between obesity and health. CONCLUSION: These preliminary findings suggest a need for more obesity education programs for adolescents, especially for those living in poverty.