Circulating Metabolomic and Lipidomic Signatures Identify a Type 2 Diabetes Risk Profile in Low-Birth-Weight Men with Non-Alcoholic Fatty Liver Disease.

The extent to which increased liver fat content influences differences in circulating metabolites and/or lipids between low-birth-weight (LBW) individuals, at increased risk of type 2 diabetes (T2D), and normal-birth-weight (NBW) controls is unknown. The objective of the study was to perform untargeted serum metabolomics and lipidomics analyses in 26 healthy, non-obese early-middle-aged LBW men, including five men with screen-detected and previously unrecognized non-alcoholic fatty liver disease (NAFLD), compared with 22 age- and BMI-matched NBW men (controls). While four metabolites (out of 65) and fifteen lipids (out of 279) differentiated the 26 LBW men from the 22 NBW controls (p ≤ 0.05), subgroup analyses of the LBW men with and without NAFLD revealed more pronounced differences, with 11 metabolites and 56 lipids differentiating (p ≤ 0.05) the groups. The differences in the LBW men with NAFLD included increased levels of ornithine and tyrosine (PFDR ≤ 0.1), as well as of triglycerides and phosphatidylcholines with shorter carbon-chain lengths and fewer double bonds. Pathway and network analyses demonstrated downregulation of transfer RNA (tRNA) charging, altered urea cycling, insulin resistance, and an increased risk of T2D in the LBW men with NAFLD. Our findings highlight the importance of increased liver fat in the pathogenesis of T2D in LBW individuals.

Clinical and molecular characterization of limb-girdle muscular dystrophy due to LAMA2 mutations.

INTRODUCTION: In this study we describe the clinical and molecular characteristics of limb-girdle muscular dystrophy (LGMD) due to LAMA2 mutations. METHODS: Five patients clinically diagnosed with LGMD and showing brain white matter hyperintensities on MRI were evaluated using laminin α2 genetic and protein testing. RESULTS: The patients had slowly progressive, mild muscular dystrophy with various degrees of CNS involvement. Epilepsy was observed in 2, and subtle symptoms of CNS involvement (mild deficit in executive functions and low IQ scores) were noted in 3 patients. Novel LAMA2 mutations were identified in all patients. The amount of laminin α2 protein in the muscle biopsies ranged from trace to about 50% compared with controls. CONCLUSIONS: This study represents the largest series of LGMD laminin α2-deficient patients and expands the clinical phenotype associated with LAMA2 mutations. The findings suggest that brain MRI could be included in the diagnostic work-up of patients with undiagnosed LGMD.

Hereditary spastic paraplegia caused by the PLP1 'rumpshaker mutation'.

BACKGROUND: Hereditary spastic paraplegia (HSP) is a group of clinically and genetically heterogeneous neurodegenerative disorders characterised by progressive spasticity and weakness in the lower limbs. Mutations in PLP1 on the X chromosome cause spastic paraplegia type 2 (SPG2) or the allelic Pelizaeus-Merzbacher Disease (PMD). The PLP1 protein is a major myelin protein involved in stabilisation and maintenance of the myelin sheath. The function of the protein has been studied in the rumpshaker mouse, which is a model of SPG2/PMD. OBJECTIVE: To characterise the phenotype of patients with the 'rumpshaker mutation.' PATIENTS: A family with HSP caused by the 'rumpshaker mutation.' RESULTS: The patients showed nystagmus during infancy and had early onset of HSP. They had normal cognition, and cerebral MRI showed relatively unspecific white matter abnormalities on T2 sequences without clear progression. Urinary urgency was reported among the female carriers. MRS of both patients showed increased myo-inositol in the white matter, while decreased N-acetylaspartate was found exclusively in the oldest patient. All evoked potential examinations were compatible with severe central demyelination, while no signs of peripheral demyelination or axonal degeneration were found. (18)F-FDG-PET scans were normal. CONCLUSION: The phenotypes of the patients reported here are the mildest described to be caused by the rumpshaker mutation and represent the mildest form among the spectrum of PLP1 related disorders. No definite symptoms in the female carriers could be ascribed to the mutation. These data suggest the pathology to be an underlying dysmyelinating disorder in combination with a central axonal degeneration.

Blood pressure and brain injury in cardiac surgery: a secondary analysis of a randomized trial.

OBJECTIVES: Brain dysfunction is a serious complication after cardiac surgery. In the Perfusion Pressure Cerebral Infarcts trial, we allocated cardiac surgery patients to a mean arterial pressure of either 70-80 or 40-50 mmHg during cardiopulmonary bypass (CPB). In this secondary analysis, we compared selected cerebral metabolites using magnetic resonance spectroscopy hypothesizing that a postoperative decrease in occipital grey matter (GM) N-acetylaspartate-to-total-creatine ratio, indicative of ischaemic injury, would be found in the high-target group. METHODS: Of the 197 patients randomized in the Perfusion Pressure Cerebral Infarcts trial, 55 and 42 patients had complete and useful data from GM and white matter (WM), respectively. Spectroscopies were done preoperatively and on postoperative days 3-6. Cognitive function was assessed prior to surgery, at discharge and at 3 months. We predefined the statistical significance level to be 0.01. RESULTS: A postoperative decrease was found in GM N-acetylaspartate-to-total-creatine ratio in the high-target group [mean difference -0.09 (95% confidence interval -0.14 to -0.04), P = 0.014]. No significant differences were found in other metabolite ratios investigated in GM or WM. No significant association was found between changes in metabolite ratios and new cerebral infarcts, WM lesion score or cognitive dysfunction. CONCLUSIONS: A higher mean arterial pressure during CPB was associated with signs of impaired cerebral metabolism, though not at the predefined significance level of 0.01. No significant association was found between metabolite ratio changes and neuroradiological pathology or change in cognitive function. CLINICAL TRIAL REGISTRATION NUMBER: Clinicaltrials.gov: NCT02185885.

Evaluation of inflammatory lesions over 2 years in facioscapulohumeral muscular dystrophy.

OBJECTIVE: We followed up patients with facioscapulohumeral muscular dystrophy (FSHD) with sequential examinations over 2 years to investigate whether inflammatory lesions always precede fat replacement, if inflammation can be resolved without muscle degeneration, and if inflammatory lesions in muscle are always followed by fat replacement. METHODS: In this longitudinal study of 10 sequential MRI assessments over 2.5 years, we included 10 patients with FSHD. We used MRI with short TI inversion recovery to identify regions of interest (ROIs) with hyperintensities indicating muscle inflammation. Muscle T2 relaxation time mapping was used as a quantitative marker of muscle inflammation. Dixon sequences quantified muscle fat replacement. Ten healthy controls were examined with a magnetic resonance scan once for determination of normal values of T2 relaxation time. RESULTS: We identified 68 ROIs with T2 elevation in the patients with FSHD. New ROIs with T2 elevation arising during the study had muscle fat content of 6.4% to 33.0% (n = 8) and 47.0% to 78.0% lesions that resolved (n = 6). ROIs with T2 elevation had a higher increase in muscle fat content from visits 1 to 10 (7.9 ± 7.9%) compared to ROIs with normal muscle T2 relaxation times (1.7 ± 2.6%; p < 0.0001). Severe T2 elevations were always followed by an accelerated replacement of muscle by fat. CONCLUSIONS: Our results suggest that muscle inflammation starts in mildly affected muscles in FSHD, is related to a faster muscle degradation, and continues until the muscles are completely fat replaced. CLINICALTRIALSGOV IDENTIFIER: NCT02159612.

Good outcome after posterior reversible encephalopathy syndrome (PRES) despite elevated cerebral lactate: a case report.

Posterior reversible encephalopathy syndrome (PRES) may cause irreversible brain damage. The diagnosis is confirmed by magnetic resonance imaging (MRI), where vasogenic edema may be seen especially in the posterior parts of the brain. MR spectroscopy (MRS) may be included to help predict the outcome by measuring selected metabolites for instance lactate. Usually lactate is immeasurable in brain tissue, but elevates in cases of hypoxia, and it has been associated with poor outcome. We report a case of a patient with eclampsia and PRES, who had elevated lactate initially, but complete remission clinically and on MRI.

Late onset of stroke-like episode associated with a 3256C-->T point mutation of mitochondrial DNA.

Mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) are usually associated with the common 3243A-->G mutation of mtDNA. Onset of stroke-like episodes usually occurs before age 30. We report a patient with late onset MELAS harboring a rare 3256C-->T mutation in the tRNA(Leu(UUR)) gene of mtDNA. The patient presented with a stroke-like episode at age 36. MRI showed a stroke-like lesion in the right parietooccipital brain region. Proton MR spectroscopy showed elevated lactate concentrations in the lesion (8.4 mmol/l), and in the mid-occipital region (2.3-3.2 mmol/l) that appeared normal on MRI. Further tests revealed evidence of a severe oxidative defect of muscle metabolism as well.

Cerebral Magnetic Resonance Spectroscopy Demonstrates Long-Term Effect of Bone Marrow Transplantation in α-Mannosidosis.

α-Mannosidosis, OMIM #248500, is an autosomal recessive lysosomal storage disease caused by acidic α-mannosidase deficiency. Treatment options include bone marrow transplantation (BMT) and, possibly in the future, enzyme replacement therapy. Brain magnetic resonance spectroscopy (MRS) enables non-invasive monitoring of cerebral treatment effect. Accumulated cerebral mannose-containing oligosaccharides were demonstrated by MRS in a patient who at age 2 years and 11 months received a BMT from a haploidentical non-carrier sibling. The cerebral mannose-containing oligosaccharides had disappeared as early as 9½ months after BMT. MRS furthermore demonstrated the persistent treatment effect at regular intervals up to 5½ years after BMT. MRS is a non-invasive tool that can demonstrate the effect of BMT treatment. Likewise, MRS may be used to demonstrate the cerebral effect of other potential treatments such as enzyme replacement therapy.

Outcome of accidental hypothermia with or without circulatory arrest: experience from the Danish Præstø Fjord boating accident.

BACKGROUND: Resuscitation guidelines for the treatment of accidental hypothermia are based primarily on isolated cases. Mortality rates are high despite aggressive treatment aimed at restoring spontaneous circulation and normothermia. METHODS: The present report is based on a boating accident where 15 healthy subjects (median age 16 (range 15-45) years) were immersed in 2 °C salt water. Seven victims were recovered in circulatory arrest with a median temperature of 18.4 °C (range 15.5-20.2 °C). They were all rewarmed with extracorporeal membrane oxygenation (ECMO) and were subsequently evaluated with advanced neuroradiological and functional testing. The remaining 7 had established spontaneous circulation without the use of ECMO. One victim drowned in the accident. RESULTS: The victims that survived the accident without circulatory arrest were predominantly females with a higher body mass index. Victims with circulatory arrest pH on arrival was a median of 6.61 (range 6.43-6.94), with ECMO being established a median of 226 (178-241)min after the accident. Magnetic resonance spectroscopy showed neuronal dysfunction in five. In five victims initial normal white matter spectra progressed to show evidence of abnormal axonal membranes. Based on the seven-level Functional Independence Measure test functional outcome was good in six circulatory arrest victims and in all without circulatory arrest. Mild to moderate cognitive dysfunction was seen in six and severe dysfunction in one circulatory arrest victim. CONCLUSION: Seven patients with profound accidental hypothermic circulatory arrest were successfully resuscitated using a management approach that included extracorporeal rewarming, followed by successive periods of therapeutic hypothermia and sedated normothermia and intensive neurorehabilitation. Seven other hypothermic victims (core temperature as low as 23 °C) that did not suffer circulatory arrest also survived the accident.

Painful tonic heat stimulation induces GABA accumulation in the prefrontal cortex in man.

Relatively little is known on pain-induced neurotransmitter release in the human cerebral cortex. We used proton magnetic resonance spectroscopy (1H-MRS) during tonic painful heat stimulation to test the hypothesis of increases in both glutamate and GABA, two neurotransmitters with a key role in pain processing. Using a 3T MR scanner, we acquired spectra from the rostral anterior cingulate cortex (rACC) in 13 healthy right-handed subjects at rest and during painful heat stimulation. The painful stimulus consisted of a suprathreshold painful tonic heat pulse, which was delivered to the right upper leg via a fMRI-compatible Peltier element. Compared to non-painful stimulation, painful tonic heat was associated with a significant increase in GABA concentrations in the rACC. No changes in glutamate concentrations were detected during noxious stimulation. This study provides the first evidence that GABA is released in the human cerebral cortex during painful stimulation. The results are in line with animal findings on the role of GABA in pain processing and with studies in humans showing analgesic efficacy of GABA-related drugs in clinical pain conditions.

1H MR spectroscopy of gray and white matter in carbon monoxide poisoning.

Carbon monoxide (CO) intoxication leads to acute and chronic neurological deficits, but little is known about the specific noxious mechanisms. (1)H magnetic resonance spectroscopy (MRS) may allow insight into the pathophysiology of CO poisoning by monitoring neurochemical disturbances, yet only limited information is available to date on the use of this protocol in determining the neurological effects of CO poisoning. To further examine the short-term and long-term effects of CO on the central nervous system, we have studied seven patients with CO poisoning assessed by gray and white matter MRS, magnetic resonance imaging (MRI) and neuropsychological testing. Five patients suffered from acute high-dose CO intoxication and were in coma for 1-6 days. In these patients, MRI revealed hyperintensities of the white matter and globus pallidus and also showed increased choline (Cho) and decreased N-acetyl aspartate (NAA) ratios to creatine (Cr), predominantly in the white matter. Lactate peaks were detected in two patients during the early phase of high-dose CO poisoning. Two patients with chronic low-dose CO exposure and without loss of consciousness had normal MRI and MRS scans. On follow-up. five of our seven patients had long-lasting intellectual impairment, including one individual with low-dose CO exposure. The MRS results showed persisting biochemical alterations despite the MRI scan showing normalization of morphological changes. In conclusion, the MRS was normal in patients suffering from chronic low-dose CO exposure; in contrast, patients with high-dose exposure showed abnormal gray and white matter levels of NAA/Cr, Cho/Cr and lactate, as detected by (1)H MRS, suggesting disturbances of neuronal function, membrane metabolism and anaerobic energy metabolism, respectively. Early increases in Cho/Cr and decreases of NAA/Cr may be related to a poor long-term outcome, but confirmation by future studies is needed.

A reduced cerebral metabolic ratio in exercise reflects metabolism and not accumulation of lactate within the human brain.

During maximal exercise lactate taken up by the human brain contributes to reduce the cerebral metabolic ratio, O(2)/(glucose + 1/2 lactate), but it is not known whether the lactate is metabolized or if it accumulates in a distribution volume. In one experiment the cerebral arterio-venous differences (AV) for O(2), glucose (glc) and lactate (lac) were evaluated in nine healthy subjects at rest and during and after exercise to exhaustion. The cerebrospinal fluid (CSF) was drained through a lumbar puncture immediately after exercise, while control values were obtained from six other healthy young subjects. In a second experiment magnetic resonance spectroscopy ((1)H-MRS) was performed after exhaustive exercise to assess lactate levels in the brain (n = 5). Exercise increased the AV(O2) from 3.2 +/- 0.1 at rest to 3.5 +/- 0.2 mM (mean +/-s.e.m.; P < 0.05) and the AV(glc) from 0.6 +/- 0.0 to 0.9 +/- 0.1 mM (P < 0.01). Notably, the AV(lac) increased from 0.0 +/- 0.0 to 1.3 +/- 0.2 mm at the point of exhaustion (P < 0.01). Thus, maximal exercise reduced the cerebral metabolic ratio from 6.0 +/- 0.3 to 2.8 +/- 0.2 (P < 0.05) and it remained low during the early recovery. Despite this, the CSF concentration of lactate postexercise (1.2 +/- 0.1 mM; n= 7) was not different from baseline (1.4 +/- 0.1 mM; n= 6). Also, the (1)H-MRS signal from lactate obtained after exercise was smaller than the estimated detection limit of approximately 1.5 mM. The finding that an increase in lactate could not be detected in the CSF or within the brain rules out accumulation in a distribution volume and indicates that the lactate taken up by the brain is metabolized.