Hyperammonemia as a Marker of Subclinical Seizures After Traumatic Cardiac Arrest

This report details the presence of hyperammonemia in a patient who sustained cardiac arrest after a traumatic amputation. Serum ammonia levels may rise due to numerous etiologies; however, few reports detail its usefulness in diagnosing subclinical seizures. In this case, we successfully utilized persistently elevated serum ammonia levels as a marker of subclinical seizures in a patient who sustained traumatic cardiac arrest

Age-related increase of kynurenic acid in human cerebrospinal fluid-IgG and beta(2)-microglobulin changes

Kynurenic acid (KYNA) is an endogenous metabolite in the kynurenine pathway of tryptophan degradation and is an antagonist at the glycine site of the N-methyl-D-aspartate as well as at the alpha 7 nicotinic cholinergic receptors. In the brain tissue KYNA is synthesised from L-kynurenine by kynurenine aminotransferases (KAT) I and II. A host of immune mediators influence tryptophan degradation. In the present study, the levels of KYNA in cerebrospinal fluid (CSF) and serum in a group of human subjects aged between 25 and 74 years were determined by using a high performance liquid chromatography method. In CSF and serum KAT I and II activities were investigated by radioenzymatic assay, and the levels of β2-microglobulin, a marker for cellular immune activation, were determined by ELISA. The correlations between neurochemical and biological parameters were evaluated. Two subject groups with significantly different ages, i.e. 50 years, p < 0.001, showed statistically significantly different CSF KYNA levels, i.e. 2.84 ± 0.16 fmol/μl vs. 4.09 ± 0.14 fmol/μl, p < 0.001, respectively; but this difference was not seen in serum samples. Interestingly, KYNA is synthesised in CSF principally by KAT I and not KAT II, however no relationship was found between enzyme activity and ageing. A positive relationship between CSF KYNA levels and age of subjects indicates a 95% probability of elevated CSF KYNA with ageing (R = 0.6639, p = 0.0001). KYNA levels significantly correlated with IgG and β2-microglobulin levels (R = 0.5244, p = 0.0049; R = 0.4253, p = 0.043, respectively). No correlation was found between other biological parameters in CSF or serum. In summary, a positive relationship between the CSF KYNA level and ageing was found, and the data would suggest age-dependent increase of kynurenine metabolism in the CNS. An enhancement of CSF IgG and β2-microglobulin levels would suggest an activation of the immune system during ageing. Increased KYNA metabolism may be involved in the hypofunction of the glutamatergic and/or nicotinic cholinergic neurotransmission in the ageing CNS

Skeletal Muscle Gender Dimorphism from Proteomics

Gross contraction in skeletal muscle is primarily determined by a relatively small number of contractile proteins, however this tissue is also remarkably adaptable to environmental factors1 such as hypertrophy by resistance exercise and atrophy by disuse. It thereby exhibits remodeling and adaptations to stressors (heat, ischemia, heavy metals, etc.)2,3. Damage can occur to muscle by a muscle exerting force while lengthening, the so-called eccentric contraction4. The contractile proteins can be damaged in such exertions and need to be repaired, degraded and/or resynthesized; these functions are not part of the contractile proteins, but of other much less abundant proteins in the cell. To determine what subset of proteins is involved in the amelioration of this type of damage, a global proteome must be established prior to exercise5 and then followed subsequent to the exercise to determine the differential protein expression and thereby highlight candidate proteins in the adaptations to damage and its repair. Furthermore, most studies of skeletal muscle have been conducted on the male of the species and hence may not be representative of female muscle

Rapid extraction of dissolved inorganic carbon from seawater and groundwater samples for radiocarbon dating

© The Author(s), 2015. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Limnology and Oceanography: Methods 14 (2016): 24-30, doi:10.1002/lom3.10066.We designed and developed a system to efficiently extract dissolved inorganic carbon (DIC) from seawater and groundwater samples for radiocarbon dating. The Rapid Extraction of Dissolved Inorganic Carbon System (REDICS) utilizes a gas-permeable polymer membrane contactor to extract the DIC from an acidified water sample in the form of carbon dioxide (CO2), introduce it to a helium gas stream, cryogenically isolate it, and store it for stable and radiocarbon isotope analysis. The REDICS system offers multiple advantages to the DIC extraction method which has been used for the last several decades at the National Ocean Sciences Accelerator Mass Spectrometry Facility (NOSAMS) at the Woods Hole Oceanographic Institution, including faster DIC extraction, streamlined analysis, and minimized set-up and prep time. The system was tested using sodium carbonate and seawater standards, duplicates of which were also processed on the water stripping line (WSL) at NOSAMS. The results demonstrate that the system successfully extracts, quantifies, and stores more than 99% of the DIC in less than 20 min. Stable and radiocarbon isotope analysis demonstrated system precision of 0.04‰ and 7.8‰, respectively. A Sargasso Sea depth profile was used to further validate the system. The results show high precision for both stable and radiocarbon analysis with pooled standard deviations of 0.02‰ and 5.6‰, respectively. A comparison between the REDICS and WSL analyses indicates a good accuracy for both stable and radio-isotope analysis.NSF Cooperative Agreements for the Operation of a National Ocean Sciences Accelerator Mass Spectrometry Facility (OCE-0753487 and OCE-123966) supported this research

Posterior positional plagiocephaly treated with cranial remodeling orthosis.

Since the recommendation that infants sleep in the supine position, there has been an increase in cases of posterior positional plagiocephaly. Even though this condition is a purely cosmetic problem, if it is severe it may affect the child psychologically. Positioning may help in mild or moderate cases, but more active treatment may be necessary in severe cases. A prospective study of 260 children treated by dynamic orthotic cranioplasty for posterior positional plagiocephaly was conducted in Lausanne from 1995 to 2001. Construction of these cranial remodelling helmets is decribed in detail. The treatment lasted 3 months on average, was effective, well tolerated, and had zero morbidity. The ideal period for initiating this therapy is between the ages of 4 and 6 months. The remodelling helmet is a convincing option which can be recommended in infants with posterior positional plagiocephaly whose skull deformity is not satisfactorily corrected by physiotherapy. It should always be used before surgery is considered for patients with recognised positional plagiocephaly in the first year of life