The effect of brain size evolution on feeding propensity, digestive efficiency, and juvenile growth

One key hypothesis in the study of brain size evolution is the expensive tissue hypothesis; the idea that increased investment into the brain should be compensated by decreased investment into other costly organs, for instance the gut. Although the hypothesis is supported by both comparative and experimental evidence, little is known about the potential changes in energetic requirements or digestive traits following such evolutionary shifts in brain and gut size. Organisms may meet the greater metabolic requirements of larger brains despite smaller guts via increased food intake or better digestion. But increased investment in the brain may also hamper somatic growth. To test these hypotheses we here used guppy (Poecilia reticulata) brain size selection lines with a pronounced negative association between brain and gut size and investigated feeding propensity, digestive efficiency (DE), and juvenile growth rate. We did not find any difference in feeding propensity or DE between large- and small-brained individuals. Instead, we found that large-brained females had slower growth during the first 10 weeks after birth. Our study provides experimental support that investment into larger brains at the expense of gut tissue carries costs that are not necessarily compensated by a more efficient digestive system.

Detection and identification of 700 drugs by multi-target screening with a 3200 Q TRAP LC-MS/MS system and library searching

The multi-target screening method described in this work allows the simultaneous detection and identification of 700 drugs and metabolites in biological fluids using a hybrid triple-quadrupole linear ion trap mass spectrometer in a single analytical run. After standardization of the method, the retention times of 700 compounds were determined and transitions for each compound were selected by a "scheduled" survey MRM scan, followed by an information-dependent acquisition using the sensitive enhanced product ion scan of a Q TRAP hybrid instrument. The identification of the compounds in the samples analyzed was accomplished by searching the tandem mass spectrometry (MS/MS) spectra against the library we developed, which contains electrospray ionization-MS/MS spectra of over 1,250 compounds. The multi-target screening method together with the library was included in a software program for routine screening and quantitation to achieve automated acquisition and library searching. With the help of this software application, the time for evaluation and interpretation of the results could be drastically reduced. This new multi-target screening method has been successfully applied for the analysis of postmortem and traffic offense samples as well as proficiency testing, and complements screening with immunoassays, gas chromatography-mass spectrometry, and liquid chromatography-diode-array detection. Other possible applications are analysis in clinical toxicology (for intoxication cases), in psychiatry (antidepressants and other psychoactive drugs), and in forensic toxicology (drugs and driving, workplace drug testing, oral fluid analysis, drug-facilitated sexual assault).

The glycine deportation system and its pharmacological consequences

The glycine deportation system is an essential component of glycine catabolism in man whereby 400 to 800mg glycine per day are deported into urine as hippuric acid. The molecular escort for this deportation is benzoic acid, which derives from the diet and from gut microbiota metabolism of dietary precursors. Three components of this system, involving hepatic and renal metabolism, and renal active tubular secretion help regulate systemic and central nervous system levels of glycine. When glycine levels are pathologically high, as in congenital nonketotic hyperglycinemia, the glycine deportation system can be upregulated with pharmacological doses of benzoic acid to assist in normalization of glycine homeostasis. In congenital urea cycle enzymopathies, similar activation of the glycine deportation system with benzoic acid is useful for the excretion of excess nitrogen in the form of glycine. Drugs which can substitute for benzoic acid as substrates for the glycine deportation system have adverse reactions that may involve perturbations of glycine homeostasis. The cancer chemotherapeutic agent ifosfamide has an unacceptably high incidence of encephalopathy. This would appear to arise as a result of the production of toxic aldehyde metabolites which deplete ATP production and sequester NADH in the mitochondrial matrix, thereby inhibiting the glycine deportation system and causing de novo glycine synthesis by the glycine cleavage system. We hypothesize that this would result in hyperglycinemia and encephalopathy. This understanding may lead to novel prophylactic strategies for ifosfamide encephalopathy. Thus, the glycine deportation system plays multiple key roles in physiological and neurotoxicological processes involving glycine.

Blockade of the renin-angiotensin system and renal tissue oxygenation as measured with BOLD-MRI in patients with type 2 diabetes

To assess whether blockade of the renin-angiotensin system (RAS), a recognized strategy to prevent the progression of diabetic nephropathy, affects renal tissue oxygenation in type 2 diabetes mellitus (T2DM) patients.

Immunologic privilege in the central nervous system and the blood-brain barrier

The brain is in many ways an immunologically and pharmacologically privileged site. The blood-brain barrier (BBB) of the cerebrovascular endothelium and its participation in the complex structure of the neurovascular unit (NVU) restrict access of immune cells and immune mediators to the central nervous system (CNS). In pathologic conditions, very well-organized immunologic responses can develop within the CNS, raising important questions about the real nature and the intrinsic and extrinsic regulation of this immune privilege. We assess the interactions of immune cells and immune mediators with the BBB and NVU in neurologic disease, cerebrovascular disease, and intracerebral tumors. The goals of this review are to outline key scientific advances and the status of the science central to both the neuroinflammation and CNS barriers fields, and highlight the opportunities and priorities in advancing brain barriers research in the context of the larger immunology and neuroscience disciplines. This review article was developed from reports presented at the 2011 Annual Blood-Brain Barrier Consortium Meeting.

Sleep-wake habits and disorders in a series of 100 adult epilepsy patients--a prospective study

The aim of the study was to assess sleep-wake habits and disorders and excessive daytime sleepiness (EDS) in an unselected outpatient epilepsy population. Sleep-wake habits and presence of sleep disorders were assessed by means of a clinical interview and a standard questionnaire in 100 consecutive patients with epilepsy and 90 controls. The questionnaire includes three validated instruments: the Epworth Sleepiness Scale (ESS) for EDS, SA-SDQ for sleep apnea (SA), and the Ullanlinna Narcolepsy Scale (UNS) for narcolepsy. Sleep complaints were reported by 30% of epilepsy patients compared to 10% of controls (p=0.001). The average total sleep time was similar in both groups. Insufficient sleep times were suspected in 24% of patients and 33% of controls. Sleep maintenance insomnia was more frequent in epilepsy patients (52% vs. 38%, p=0.06), whereas nightmares (6% vs. 16%, p=0.04) and bruxism (10% vs. 19%, p=0.07) were more frequent in controls. Sleep onset insomnia (34% vs. 28%), EDS (ESS >or=10, 19% vs. 14%), SA (9% vs. 3%), restless legs symptoms (RL-symptoms, 18% vs. 12%) and most parasomnias were similarly frequent in both groups. In a stepwise logistic regression model loud snoring and RL-symptoms were found to be the only independent predictors of EDS in epilepsy patients. In conclusion, sleep-wake habits and the frequency of most sleep disorders are similar in non-selected epilepsy patients as compared to controls. In epilepsy patients, EDS was predicted by a history of loud snoring and RL-symptoms but not by SA or epilepsy-related variables (including type of epilepsy, frequency of seizures, and number of antiepileptic drugs).