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81.
AbstractThe use of computers to model biological systems is a relatively new research tool. For examplel it is possible to write mathematical systems to model neuronal activity involved in memory and learning and to model blood flow in any organ such as the brain. There is also an interest in designing computer-controlled machines to simulate human activities such as hand movements and vision. One of the most important uses of computer modeling is as a research tool to test hypotheses and aid in formulating new hypotheses. This enables the investigator to apply preliminary tests on several experimental strategies and select for animal experimentation the ones that are most likely to produce unambiguous and interpretable results. In the following articlel we describe a computer model of neuron toxicity in the mammalian spinal cord. [Neural Res 1997; 19: 340–348] 相似文献
82.
Isaac León Luchina 《Contemporary psychoanalysis》2013,49(1):104-108
83.
Isaac Arthur 《Postgraduate medicine》2013,125(6):468-469
Diagnostic procedures for study of the urinary tract are easily adaptable to patients of all age groups, and technical developments have made possible the surgical correction of many anomalies of the genitourinary tract. Early recognition and correction, when possible, are mandatory. Obstructive anomalies are of the greatest immediate importance because of their adverse effect on renal function. 相似文献
84.
Donel M. Martin Natalie Katalinic Anna Ingram Isaac Schweitzer Deidre J. Smith Dusan Hadzi-Pavlovic Colleen K. Loo 《Journal of psychiatric research》2013
Cognitive side-effects from electroconvulsive therapy (ECT) can be distressing for patients and early detection may have an important role in guiding treatment decisions over the ECT course. This prospective study examined the utility of an early cognitive screening battery for predicting cognitive side-effects which develop later in the ECT course. The screening battery, together with the Mini Mental Status Examination (MMSE), was administered to 123 patients at baseline and after 3 ECT treatments. A more detailed cognitive battery was administered at baseline, after six treatments (post ECT 6) and after the last ECT treatment (post treatment) to assess cognitive side-effects across several domains: global cognition, anterograde memory, executive function, speed and concentration, and retrograde memory. Multivariate analyses examined the predictive utility of change on items from the screening battery for later cognitive changes at post ECT 6 and post treatment. Results showed that changes on a combination of items from the screening battery were predictive of later cognitive changes at post treatment, particularly for anterograde memory (p < 0.01), after controlling for patient and treatment factors. Change on the MMSE predicted cognitive changes at post ECT 6 but not at post treatment. A scoring method for the new screening battery was tested for discriminative ability in a sub-sample of patients. This study provides preliminary evidence that a simple and easy-to-administer measure may potentially be used to help guide clinical treatment decisions to optimise efficacy and cognitive outcomes. Further development of this measure and validation in a more representative ECT clinical population is required. 相似文献
85.
Rosa Artese Daniel D’Osvaldo Isaac Molocznik Haydee Benencia Jorge Oviedo José Burdman 《Neurological research》2013,35(5):415-417
AbstractWe report on a series of 48 patients, ages 74 to 20 year, with hypophyseal adenomas. Of these, 46 (96%) had secreting tumors, 3 had Cushing’s disease, 9 had somatotrophinomas, and 34 (29 females and 5 males) had prolactinomas. Thirty cases were diagnosed as intrasellar adenomas (62%) while the remaining eighteen (38%) presented extrasellar expansion. Of 9 acromegalic patients, 7 had typical clinical and biochemical features while 2 were exclusively prognatic with normal basal GH levels, but abnormal dynamic tests. Prolactinomas were npninvasive in women and faster growing and more extensive in men. Forty seven patients underwent surgery. Five of these required craniotomy and the rest were approached through the sphenoidal bone (TSf). Remission was achieved in Cushing’s disease, acromegaly, and female intrasellar prolactinomas. Larger tumors such as nonsecreting adenomas and male prolactinomas showed poor results after undergoing subtotal resections, with persistance of endocrinological disturbances. From our findings it appears that these tumors are not more aggressive in youths than in adults. Because there was a close relationship between tumor size, invasiveness, and the patients, final outcome, we conclude that early diagnosis and treatment is essential. Frequent complaints in adolescents such as irregular menses, retarded puberty, and growth disorders should be thoroughly investigated and not merely considered as transient or ‘functional’ [Neural Res 1998; 20: 415–417] 相似文献
86.
Isaac Marin-Valencia Levi B Good Qian Ma Craig R Malloy Juan M Pascual 《Journal of cerebral blood flow and metabolism》2013,33(2):175-182
It has been postulated that triheptanoin can ameliorate seizures by supplying the tricarboxylic acid cycle with both acetyl-CoA for energy production and propionyl-CoA to replenish cycle intermediates. These potential effects may also be important in other disorders associated with impaired glucose metabolism because glucose supplies, in addition to acetyl-CoA, pyruvate, which fulfills biosynthetic demands via carboxylation. In patients with glucose transporter type I deficiency (G1D), ketogenic diet fat (a source only of acetyl-CoA) reduces seizures, but other symptoms persist, providing the motivation for studying heptanoate metabolism. In this work, metabolism of infused [5,6,7-13C3]heptanoate was examined in the normal mouse brain and in G1D by 13C-nuclear magnetic resonance spectroscopy, gas chromatography-mass spectrometry (GC-MS), and liquid chromatography-mass spectrometry (LC-MS). In both groups, plasma glucose was enriched in 13C, confirming gluconeogenesis from heptanoate. Acetyl-CoA and glutamine levels became significantly higher in the brain of G1D mice relative to normal mice. In addition, brain glutamine concentration and 13C enrichment were also greater when compared with glutamate in both animal groups, suggesting that heptanoate and/or C5 ketones are primarily metabolized by glia. These results enlighten the mechanism of heptanoate metabolism in the normal and glucose-deficient brain and encourage further studies to elucidate its potential antiepileptic effects in disorders of energy metabolism. 相似文献
87.
Elizabeth A. Maher Isaac Marin‐Valencia Robert M. Bachoo Tomoyuki Mashimo Jack Raisanen Kimmo J. Hatanpaa Ashish Jindal F. Mark Jeffrey Changho Choi Christopher Madden Dana Mathews Juan M. Pascual Bruce E. Mickey Craig R. Malloy Ralph J. DeBerardinis 《NMR in biomedicine》2012,25(11):1234-1244
Glioblastomas and brain metastases demonstrate avid uptake of 2‐[18F]fluoro‐2‐deoxyglucose by positron emission tomography and display perturbations of intracellular metabolite pools by 1H MRS. These observations suggest that metabolic reprogramming contributes to brain tumor growth in vivo. The Warburg effect, excess metabolism of glucose to lactate in the presence of oxygen, is a hallmark of cancer cells in culture. 2‐[18F]Fluoro‐2‐deoxyglucose‐positive tumors are assumed to metabolize glucose in a similar manner, with high rates of lactate formation relative to mitochondrial glucose oxidation, but few studies have specifically examined the metabolic fates of glucose in vivo. In particular, the capacity of human brain cancers to oxidize glucose in the tricarboxylic acid cycle is unknown. Here, we studied the metabolism of human brain tumors in situ. [U‐13 C]Glucose (uniformly labeled glucose, i.e. d ‐glucose labeled with 13 C in all six carbons) was infused during surgical resection, and tumor samples were subsequently subjected to 13C NMR spectroscopy. The analysis of tumor metabolites revealed lactate production, as expected. We also determined that pyruvate dehydrogenase, turnover of the tricarboxylic acid cycle, anaplerosis and de novo glutamine and glycine synthesis contributed significantly to the ultimate disposition of glucose carbon. Surprisingly, less than 50% of the acetyl‐coenzyme A pool was derived from blood‐borne glucose, suggesting that additional substrates contribute to tumor bioenergetics. This study illustrates a convenient approach that capitalizes on the high information content of 13C NMR spectroscopy and enables the analysis of intermediary metabolism in diverse cancers growing in their native microenvironment. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
88.
89.
Francisco J. Padillo Juan F. Ruiz‐Rabelo Adolfo Cruz María D. Perea Inmaculada Tasset Pedro Montilla Isaac Túnez Jordi Muntané 《Journal of pineal research》2010,49(3):264-270
Abstract: Pancreatic cancer is a major health problem because of the aggressiveness of the disease and the lack of effective systemic therapies. Melatonin (MEL) has antioxidant activity and prevents experimental genotoxicity. The specific inhibitor of cyclooxygenase‐2 (COX‐2), celecoxib (CEL), increases the efficacy of chemoradiotherapy in advanced pancreatic cancer. The objective of the study was the comparison and synergic effect of MEL and CEL during either the induction or progression phases of the tumor process, measuring parameters of oxidative stress, number of tumor nodules and survival of animals with pancreatic cancer. Pancreatic cancer was induced by N‐nitrosobis (2‐oxopropyl)amine) (BOP) in Syrian hamsters. Melatonin and/or CEL were administered during the induction, postinduction as well as during both phases. The presence of tumor nodules were observed macroscopically in pancreatic and splenic areas, and the levels of lipoperoxides (LPO), reduced glutathione (GSH), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH‐Px) in pancreatic tissue were measured. The increases in tumor nodules and LPO as well as the reductions in GSH and enzymatic antioxidants in the pancreas induced by BOP were related to a lower survival rate of animals. The administration of MEL exerted a more potent beneficial effect than CEL treatment on the reduction in tumor nodules, oxidative stress and death of experimental BOP‐treated animals. The combined treatment only exerted a synergistic beneficial effect when administered during the induction phase. Melatonin by itself had significant beneficial actions in improving the survival of hamsters. 相似文献
90.
The value of parental report for diagnosis and management of dehydration in the emergency department
STUDY OBJECTIVES: We define the predictive value of parents' computer-based report for history and physical signs of dehydration for a primary outcome of percentage of dehydration (fluid deficit) and 2 secondary outcomes: clinically important acidosis and hospital admission. We also sought to compare the reports of physical signs related to dehydration made by parents and nurses. METHODS: We performed a prospective observational trial in an urban pediatric emergency department. A convenience sample of parents completed a computer-based interview covering historical details and physical signs (ill appearance, sunken fontanelle, sunken eyes, decreased tears, dry mouth, cool extremities, and weak cry) related to dehydration. Nurses independently completed an assessment of physical signs for enrolled children. The primary outcome was the degree of dehydration (fluid deficit), which was defined as the percentage difference between initial ED weight and stable final weight after the illness. Secondary outcomes included clinically important acidosis (defined as a serum CO(2) value of =15 mEq/L) and hospital admission. RESULTS: One hundred thirty-two parent-child dyads comprised the final sample. Parent-reported data manifested higher sensitivity (range 73% to 100%) than specificity (range 0% to 49%) for the prediction of dehydration of 5% or greater. Likelihood ratios (LRs) near zero (<0.1) suggest that a normal history of fluid intake and urine output reduced the likelihood of significant dehydration. Parental report of a normal tearing state reduced the likelihood of significant dehydration and clinically important acidosis (negative LRs of 0.4 and 0.1, respectively). Two physical signs reported by parents, sunken fontanelle and decreased tears, were associated with hospital admission (positive LR of 3.4 and 4.0, respectively). CONCLUSION: Parents' report of history and observations for children captured through computer-based interview demonstrates predictive value for relevant outcomes in dehydration. 相似文献