Correlation between cerebral neurotransmitters levels by proton magnetic resonance spectroscopy and HbA1c in patients with type 2 diabetes

BACKGROUND Cognitive dysfunction is the main manifestation of central neuropathy.Although cognitive impairments tend to be overlooked in patients with diabetes mellitus(DM),there is a growing body of evidence linking DM to cognitive dysfunction.Hyperglycemia is closely related to neurological abnormalities,while often disregarded in clinical practice.Changes in cerebral neurotransmitter levels are associated with a variety of neurological abnormalities and may be closely related to blood glucose control in patients with type 2 DM(T2DM).AIM To evaluate the concentrations of cerebral neurotransmitters in T2DM patients exhibiting different hemoglobin A1c(HbA1c)levels.METHODS A total of 130 T2DM patients were enrolled at the Department of Endocrinology of Shanghai East Hospital.The participants were divided into four groups according to their HbA1c levels using the interquartile method,namely Q1(<7.875%),Q2(7.875%-9.050%),Q3(9.050%-11.200%)and Q4(≥11.200%).Clinical data were collected and measured,including age,height,weight,neck/waist/hip circumferences,blood pressure,comorbidities,duration of DM,and biochemical indicators.Meanwhile,neurotransmitters in the left hippocampus and left brainstem area were detected by proton magnetic resonance spectroscopy.RESULTS The HbA1c level was significantly associated with urinary microalbumin(mALB),triglyceride,low-density lipoprotein cholesterol(LDL-C),homeostasis model assessment of insulin resistance(HOMA-IR),and beta cell function(HOMA-β),N-acetylaspartate/creatine(NAA/Cr),and NAA/choline(NAA/Cho).Spearman correlation analysis showed that mALB,LDL-C,HOMA-IR and NAA/Cr in the left brainstem area were positively correlated with the level of HbA1c(P<0.05),whereas HOMA-βwas negatively correlated with the HbA1c level(P<0.05).Ordered multiple logistic regression analysis showed that NAA/Cho[Odds ratio(OR):1.608,95%confidence interval(95%CI):1.004-2.578,P<0.05],LDL-C(OR:1.627,95%CI:1.119-2.370,P<0.05),and HOMA-IR(OR:1.107,95%CI:1.031-1.188,P<0.01)were independent predictors of poor glycemic control.CONCLUSION The cerebral neurotransmitter concentrations in the left brainstem area in patients with T2DM are closely related to glycemic control,which may be the basis for the changes in cognitive function in diabetic patients.

Application of proton magnetic resonance spectroscopy in metabolic alterations of prefrontal white and gray matter in depression adolescents

BACKGROUND Cases of depression among adolescents are gradually increasing.The study of the physiological basis of cognitive function from a biochemical perspective has therefore been garnering increasing attention.Depression has been hypothesized to be associated with the brain biochemical metabolism of the anterior cingulate gyrus,frontal lobe white matter,and the thalamus.AIM To explore the application of proton magnetic resonance spectroscopy(1H-MRS)in the metabolic alterations in the prefrontal white matter(PWM)and gray matter(GM)in adolescents with depression.METHODS 1H-MRS was performed for semi-quantitative analysis of the biochemical metabolites N-acetylaspartate(NAA),choline(Cho)complexes,creatine(Cr),and myoinositol(mI)in bilateral PWM,anterior cingulate GM,and thalami of 31 adolescent patients with depression(research group)and 35 healthy adolescents(control group),and the NAA/Cr,Cho/Cr,and mI/Cr ratios were calculated.Meanwhile,Hamilton Depression Scale(HAMD)and Wechsler Memory Scale were used to assess the degree of depression and memory function in all adolescents.The correlation of brain metabolite levels with scale scores was also analyzed.RESULTS The research group had markedly higher HAMD-24 scores and lower memory quotient(MQ)compared with the control group(P<0.05).Adolescents with depression were found to have lower bilateral PWM NAA/Cr and Cho/Cr ratios compared with healthy adolescents(P<0.05).The mI/Cr ratios were found to be similar in both groups(P>0.05).The bilateral anterior cingulate GM NAA/Cr,Cho/Cr,and mI/Cr also did not demonstrate marked differences(P>0.05).No statistical inter-group difference was determined in NAA/Cr of the bilateral thalami(P>0.05),while bilateral thalamic Cho/Cr and mI/Cr were reduced in teenagers with depression compared with healthy adolescents(P<0.05).A significant negative correlation was observed between the HAMD-24 scores in adolescents with depression with bilateral PWM NAA/Cr and Cho/Cr and were inversely linked to bilateral thalamic Cho/Cr and mI/Cr(P<0.05).In adolescents with depressions,MQ positively correlated with right PWH NAA/Cr,left PWH Cho/Cr,and bilateral thalamic Cho/Cr and mI/Cr.CONCLUSION PWM and thalamic metabolic abnormalities might influence teen depression,and the reduction in bilateral PWM NAA/Cr and Cho/Cr could be related to the neuropathology of adolescents with depression suffering from memory impairment.There exists a possibility of dysfunction of nerve cell membrane phospholipids in the thalami of adolescent patients with depression.

Application of Proton Magnetic Resonance Spectroscopy and Computerized Tomography in the Diagnosis and Treatment of Nonalcoholic Fatty Liver Disease

In order to investigate the application of proton magnetic resonance spectroscopy （ill-MRS） and computerized tomography （CT） in the quantitative diagnosis of nonalcoholic fatty liver disease （NAFLD） and evaluation of therapeutic effects, 22 patients with NAFLD were selected according to the Chinese Medical Association＇s （CMA） standard of the NAFLD in comparison with 20 healthy volunteers （as control group）. Blood samples for biochemistry were collected. The severity of hepatosteatosis was evaluated by ^1H-MRS scan and CT scan of liver. The intrahepatic content of lipid （IHCL） and CT value ratio of liver to spleen were calculated. The patients in NAFLD group were treated with Ganzhixiao Capsule for 8 weeks. The changes in IHCL and CT value ratio of liver to spleen were observed before and after treatment. In NAFLD group serum ALT, TG, IHCL calculated by ^1HMRS were increased and CT value ratio of liver to spleen decreased significantly as compared with control group. After treatment for 8 weeks serum ALT, TG, IHCL were decreased significantly, while CT value ratio of liver to spleen increased significantly in NAFLD group. It was suggested that IHCL could be measured precisely by ^1HMRS. NAFLD was treated effectively by Ganzhixiao capsule.

Evaluation of mannitol effect in patients with acute hepatic failure and acute-on-chronic liver failure using conventional MRI,diffusion tensor imaging and in-vivo proton MR spectroscopy

AIM： To evaluate the effect of an intravenous bolus of mannitol in altering brain metabolites, brain water content, brain parenchyma volume, cerebrospinal fluid （CSF） volume and clinical signs in controls and in patients with acute liver failure （ALF） and acute- on-chronic liver failure （ACLF）, by comparing changes in conventional magnetic resonance imaging （MRI）, in vivo proton magnetic resonance spectroscopy （PMRS） and diffusion tensor imaging （DTI） before and after its infusion.METHODS： Five patients each with ALF and ACLF in grade 3 or 4 hepatic encephalopathy and with clinical signs of raised intracranial pressure were studied along with five healthy volunteers. After baseline MRI, an intravenous bolus of 20% mannitol solution was given over 10 min in controls as well as in patients with ALF and ACLE Repeat MRI for the same position was acquired 30 rnin after completing the rnannitol injection. RESULTS： No statistically significant difference was observed between controls and patients with ALF and ACLF in metabolite ratios, DTI metrics and brain volume or CSF volume following 45 rain of mannitol infusion. There was no change in clinical status at the end of post-mannitol imaging. CONCLUSION： The osmotic effect of mannitol did not result in significant reduction of brain water content, alteration in metabolite ratios or any change in the clinical status of these patients during or within 45 min of mannitol infusion.

Metabolic changes of prefrontal cerebral lobe,white matter and cerebellum in patients with post-stroke depression A proton magnetic resonance spectroscopy study

BACKGROUND： Proton magnetic resonance spectroscopy （IH-MRS） non-invasively detects changes in chemical substances in the brain, which reflects the pathological metabolism.OBJECTIVE： To investigate changes in N-acetyl-aspartate （NAA）, choline （Cho）, creatine （Cr）, and myoinositol （MI） in the gray and white matter of cerebral prefrontal lobe and cerebellum of patients with differential degrees of post-stroke depression （PSD） using ^1H-MRS. DESIGN： A case control study. SETTING： The First Affiliated Hospital of the Dalian Medical University. PARTICIPANTS： A total of 38 patients with stroke （28 male and l0 female patients, aged 40 to 79 years） were selected from the Department of Neurology, 1st Affiliated Hospital, Dalian Medical University, from February to October in 2004. All subjects met the DSM-IV criteria for cerebrovascular disease and depression. The degree of depression was defined according to Hamilton criteria. 38 patients with PSD were divided into two groups according to the time after ischemia, 20 patients in the acute group with less than 10 days after ischemic attack （mild： 16 patients, moderate/severe： 4 patients） and 18 patients in the chronic group with more than l l days after ischemic attack （mild： 15 patients, moderate/severe： 3 patients）. Seventeen healthy volunteers with matching age from 41 to 80 years were examined as a control group. The study was approved by the Medical Ethics Committee of the University Medical Center Utrecht, and each participant signed an informed consent form. METHODS： Spectra were acquired by multi-voxel point-resolved spectroscopy （PRESS） sequence with GE signal.5T MR/i, localized in prefrontal cerebral lobe and cerebellum. Values of NAA, Cho, MI, and Cr ere compared between different graded PSD patients and control subjects with one-way analysis of variance in software SPSS 11.5. MAIN OUTCOME MEASURES： Metabolite concentration in different brain regions of interest. Difference in metabolites between distinctly graded PSD patients and control subjects. Exclusion of age-effects on metabolites. RESULTS： Metabolite concentrations of different brain regions： A significant rise in the Cho/Cr ratio was detected in the acute and chronic group compared to the control group. The ratio change was more significant in the acute group （P 〈 0.05）. There was no significant difference between these three groups for other metabolites detected by IH-MRS in the right frontal white matter, bilateral frontal grey matter, and cerebellum （P 〉 0.05）. Comparison of metabolite levels among differently graded PSD patients and control subjects： a significant increase in the Cho/Cr ratio was detected in the left frontal white matter compared to the control group （P 〈 0.05）. There was no significant difference in age between patients in the stroke groups and the control group （P 〉 0.05）, and similarly, there was no significant correlation between age and absolute or relative values in the control group （P 〉 0.05）. CONCLUSION： Abnormalities of frontal lobe in PSD were located in the white matter. There was early abnormality of metabolic substance in PSD.

Neurochemical metabolites in the medial prefrontal cortex in bipolar disorder A proton magnetic resonance spectroscopy study

The aim of this study was to investigate proton magnetic resonance spectroscopy metabolite values in the medial prefrontal cortex of individuals with euthymic bipolar disorder. The subjects consisted of 15 patients with euthymic bipolar disorder type I and 15 healthy controls. We performed proton magnetic resonance spectroscopy of the bilateral medial prefrontal cortex and measured levels of N-acetyl aspartate, choline and creatine. Levels of these three metabolites in the medial prefrontal cortex were found to be lower in patients with bipolar disorder compared with healthy controls. A positive correlation was found between illness duration and choline levels in the right medial prefrontal cortex. Our study suggests that during the euthymic period, there are abnormalities in cellular energy and membrane phospholipid metabolism in the medial prefrontal cortex, and that this may impair neuronal activity and integrity.

Application of proton MR spectroscopy on evaluation of radiotherapy treated intracranial tumors

Objective： To evaluate the clinical application of proton magnetic resonance spectroscopy （1HMRS） in patients with radiotherapy treated intracranial tumors. Methods： Forty patients with intracranial tumors underwent multivoxel 1HMRS examination before and after radiotherapy. The concentrations of N-acetyl aspartate （NAA）, choline （Cho） and creatine （Cr） were obtained both in the tumors and the contralateral normal brain regions, The ratios of NANCr, Cho/Cr and Cho/NAA were calculated at the same time and follow-up one year. Results： （1） After radiotherapy, tumors inhibited by radiation had decreased Cho, NAA and Cr on proton MRS. Some cases showed necrotic wave. （2） During the one year follow-up, local tumor recurred in 8 cases and their Cho and Cho/NAA increased high again. Other cases without recurrence, HMRS showed no change. Conclusion： Multivoxel proton MR spectroscopy is available for study of tumor metabolites after radiotherapy and it is a valuable method in the evaluation of radiotherapy treated tumors,

AQP4 expression and its correlation with the Lac and NAA using proton magnetic resonance spectroscopy after rat cerebral ischemia

Objective： To determine whether AQP4 expression is associated with lactate （Lac） and Nacetyl aspartate （NAA） and with apparent diffusion coefficient （ADC） abnormality after rat cerebral ischemia. Methods： The time courses of ADC and lactate and NAA assessed by proton magnetic resonance spectroscopy （^1HMRS） were investigated at the time point of 6 h, and 1, 3, 7 d after rat cerebral ischernia induced by middle cerebral artery occlusion. Expression of AQP4 mRNA and protein were measured using RT-PCR and Western blot analysis respectively. Results： Significant reductions of NAA concentration and increases of lactate concentration were found after rat cerebral ischemia. The expressions of AQP4 mRNA t and protein were increased at 6 h, and reached the peak at 1-3 d, then began to decrease at 7 d after rat cerebral ischemia. The expression of AQP4 was significantly correlated with NAA （rRT = -0. 856, rw = -0. 927, P〈0.01）, and with lactate （rw=0. 473, rRT=0. 413, P〈0.05）, and with ADC values during the period of 1-7d after rat cerebralischemia （rw=0.984, rRT=0.925, P〈0.05）. In addition, correlations between Lac and the ADC values（r=-0. 677, P〈0.05）and between NAA and ADC values during the period of 1-7 d after rat cerebralischemia （r=0.909, P（0.05） were also observed. Conclusion： The data suggest that AQP4 is involved in the transport of water when brain edema is formed and cell membrane integrity is lost.

Preliminary study in vitro brain tumor with high resolution magic angle spinning proton magnetic resonance spectroscopy

Objective： To explore water soluble metabolite features of brain tumor specimens with HRMAS-^1HMRS and its potential clinical value. Methods： There were thirty cases of pathologically proven brain tumor, including 6 Ⅰ-Ⅱ grade astrocytomas, 7 Ⅲ grade anaplastic astrocytomas, 10 IV grade glioblastomas and 7 meningiomas. Used Varian Company 600 MHz spectrometer with the Nano-probe for acquisition HRMASJHMRS, which was postprocessed with jMRUI 3.2 version software. These metabolic probability and their ratios to Cr were summed. Results： （1） HRMAS-^1HMRS could resolve NAA, PCr/Cr, GPC ± PCho ± Cho, Glu/GIn, Gly, Tau, Ala, Lac, ml and so on. All samples showed Lac, 6 samples showed unknown single peak at 3.72 ppm or 3.90 ppm. （2） The mean Cho/Cr of 6 Ⅰ-ⅡI grade astrocytomas was 2.42 ± 1.01 （P = 0.003, compared with glioblastoma）. The mean Cho/Cr of 7 anaplastic astrocytomas was 3.48 ± 0.59 （P = 0.01, compared with glioblastoma）. The Cho/Cr of 10 glioblastomas broadly ranged from 0.9 to 11.3 （mean 5.40 ± 1.23）. From Ⅰ-Ⅱ grade astrocytoma to glioblastoma, Ala/Cr, Tau/Cr and Gly/Cr trends were increased; the mean Ala/Cr of glioma was 0.31 ± 0.13. （3） Meningiomas showed higher Ala and Cho. Their Cr was lower than that of gliomas. 4/7 cases had no NAA, 3/7 patients had lower NAA. Mean Cho/Cr was 3.56 ± 1.01, Ala/Cr was 0.53 ±0.28 （P = 0.006, compared with glioma）. Conclusion： HRMAS-^1HMRS can show further details in vivo MRS, resolve in vivo spectroscopic metabolite of Cho compound and differentiate the extent of benign and malignant glioma. With the increase in the malignant degree of gliomas, Cho, ml, Ala, Tau and Gly will increase. HRMAS-^1HMRS is the only method of isotropic spectroscopy for pathological specimens.

Methylmercury chloride damage to the adult rat hippocampus cannot be detected by proton magnetic resonance spectroscopy

Previous studies have found that methylmercury can damage hippocampal neurons and accord- ingly cause cognitive dysfunction. However, a non-invasive, safe and accurate detection method for detecting hippocampal injury has yet to be developed. This study aimed to detect methylmercury-induced damage on hippocampal tissue using proton magnetic resonance spectroscopy. Rats were given a subcutaneous injection of 4 and 2 mg/kg methylmercury into the neck for 50 consecutive days. Water maze and pathology tests confirmed that cognitive function had been impaired and that the ultrastructure of hippocampal tissue was altered after injection. The results of proton magnetic resonance spectroscopy revealed that the nitrogen-acetyl aspartate/ creatine, choline complex/creatine and myoinositol/creatine ratio in rat hippocampal tissue were unchanged. Therefore, proton magnetic resonance spectroscopy can not be used to determine structural damage in the adult rat hippocampus caused by methylmercury chloride.

Quantitative analysis of glutamate compounds in the swine brain following central analgesics nasal spray using proton magnetic resonance spectroscopy and linear combination model

BACKGROUND： In localized brain proton magnetic resonance spectroscopy （^1H-MRS）, metabolite levels are often expressed as ratios, rather than absolute concentrations. Frequently, the denominator is creatine, which is assumed to be stable in normal, as well as many pathological, states. However, in vivo creatine levels do not remain constant. Therefore, absolute metabolite measurements, which provide the precise concentrations of certain chemical compounds, are superior to metabolite ratios for determining pathological and evolutional changes. OBJECTIVE： To investigate the feasibility of quantification analysis of brain metabolite changes caused by central analgesics nasal spray using the ^1H-MRS and linear combination model （LCModel） methods. DESIGN, TIME AND SETTING： This neuroimaging, observational, animal study was performed at the Laboratory of the Department of Medical Imaging, Second Affiliated Hospital, Medical College, Shantou University, China from July to December 2007. MATERIALS： Butorphanol tartrate nasal spray, as a mixed agonist-antagonist opioid analgesic, was purchased from Shanghai Hengrui Pharmacy, China. A General Electric Signa 1.5T System （General Electric Medical Systems, Milwaukee, WI, USA） and LCModel software （Stephen Provencher, Oakville, Ontario, Canada） were used in this study. METHODS： MRS images were acquired in ten healthy swine aged 2 weeks using single-voxel point-resolved spectroscopic sequence. A region of interest （2 cm × 2 cm × 2 cm） was placed in the image centers of maximum brain parenchyma. Repeated MRS scanning was performed 15-20 minutes after intranasal administration of 1 mg of butorphanol tartrate. Three settings of repetition time/echo time were selected before and after nasal spray administration 3 000 ms/30 ms,1 500 ms/30 ms, and 3 000 ms/50 ms. Metabolite concentrations were estimated by LCModel software. MAIN OUTCOME MEASURES： ^1H-MRS spectra was obtained using various repetition time/echo time settings. Concentrations of glutamate compounds （glutamate ＋ glutamine）, N-acetyl aspartate, and choline were detected in swine brain prior to and following nasal spray treatment. RESULTS： The glutamate compounds curve was consistent with original spectra, when a repetition time/echo time of 3 000 ms/30 ms was adopted. Concentrations of glutamate compounds, N-acetyl aspartate, and choline decreased following administration. The most significant reduction was observed in glutamate compound concentrations from （9.28 ± 0.54） mmol/kg to （7.28 ± 0.54） mmol/kg （P 〈 0.05）. CONCLUSION： ^1H-MRS and LCModel software were effectively utilized to quantitatively analyze and measure brain metabolites. Glutamate compounds might be an important neurotransmitter in central analgesia.

Quiet rest ameliorates biochemical metabolism in the brain in a simple concussion rabbit model Evaluation of hydrogen proton magnetic resonance spectroscopy

The present study analyzed changes in the biochemical metabolites N-acetyl aspartate, choline, and creatine in a simple concussion rabbit model following quiet rest, hyperbaric oxygen therapy, or interference stimulation through the use of hydrogen proton magnetic resonance spectroscopy detection. Experimental findings showed that brain N-acetyl aspartate and choline peak values significantly decreased, while creatine peak values significantly increased following simple concussion. Following treatments, N-acetyl aspartate and choline peaks returned to normal levels in the quiet rest and hyperbaric oxygen therapy groups, but no changes were observed in the interference stimulation group. Results demonstrated abnormal changes in the brain biochemical metabolism environment following simple concussion. Quiet rest was shown to play an important role in restoration of biochemical metabolism following simple concussion.

Liver fat content determined by magnetic resonance imaging and spectroscopy

Hepatic steatosis as the most prevalent liver disorder can either be related to alcoholic liver disease (ALD) or non-alcoholic fatty liver disease (NAFLD). In both conditions, hepatocytes excessively accumulate fatcontaining vacuoles within their cytoplasm, which is the key histological feature. In contrast to ALD, NAFLD is commonly associated with metabolic syndrome, obesity and insulin resistance. To determine increased liver fat content, liver biopsy is currently considered the gold standard. Besides the invasive technique, various other non-invasive techniques have been developed, such as ultrasound, computed tomography (CT), magnetic resonance spectroscopy (MRS) and magnetic resonance imaging (MRI) based methods. Among these techniques, ultrasound and CT provide only qualitative information about hepatic steatosis, whereas MRS-or MRI-based methods are able to determine even small amounts of fat accurately. These non-invasive magnetic resonance techniques have already proven their great potential, especially in longitudinal and cross-sectional studies regarding various metabolic conditions and medical treatment regimens. In this review, the most common, non-invasive MRS/MRI techniques for assessment of intrahepatic lipid content are described with their inherent advantages and limitations.

IN VIVO ~1 H MAGNETIC RESONANCE SPECTROSCOPY IN EVALUATION OF HEPATOCELLULAR CARCINOMA AND ITS EARLY RESPONSE TO TRANSCATHETER ARTERIAL CHEMOEMBOLIZATION

Objective To investigate the value of in vivo proton magnetic resonance spectroscopy （MRS） in the assessment of hepatocelhilar carcinoma （HCC） and monitor its metabolic change shortly after transcatheter arterial chemoembolization （TACE）. Mothoda In this prospective study, 28 consecutive patients with large HCC （ ≥3 cm in diameter） confirmed by fine needle aspiration biopsy were recruited. The ^1H MRS of all hepatic lesions and some uninvolved liver parenchyma were performed with 1.5T whole body MR scanner. Among them, 15 cases were evaluated again about one week after TACE. The main metabolites such as choline and lipid before and after interventional therapy were measured to assess the early response of the tumor. The technical success rate of IH MRS in liver was high （33/41, 80% ）, closely related to breath motion, location of lesion, and size of voxeL In spectra, the choline compound peak of HCC elevated compared with uninvolved liver parenchyma. After TACE, both the amplitude and the area of choline resonance peak significantly descended （ choline-to-lipid ratios from 0.352±0. 080 to 0. 167±0. 030, P = 0. 026; from 0. 205±0. 060 to 0. 070±0. 020, P = 0. 042, respectively ） ; yet lipid resonance peak ascended. Conclusions In vivo tH MRS is technically feasible for the evaluation of large focal hepatic lesions, however, the reproducibility and stability are not as good as routine MR scan. IH MRS can monitor the early stage metabolic changes of HCC after TACE but limitation like quantification still exists.

In vivo magnetic resonance spectroscopy of liver tumors and metastases

Primary liver cancer is the fifth most common malignancy in men and the eighth in women worldwide. The liver is also the second most common site for metastatic spread of cancer. To assist in the diagnosis of these liver lesions non-invasive advanced imaging techniques are desirable. Magnetic resonance (MR) is commonly used to identify anatomical lesions, but it is a very versatile technique and also can provide specific information on tumor pathophysiology and metabolism, in particular with the application of MR spectroscopy (MRS). This may include data on the type, grade and stage of tumors, and thus assist in further management of the disease. The purpose of this review is to summarize and discuss the available literature on proton, phosphorus and carbon-13-MRS as performed on primary liver tumors and metastases, with human applications as the main perspective. Upcoming MRSapproaches with potential applications to liver tumors are also included. Since knowledge of some technical background is indispensable to understand the results, a basic introduction of MRS and some technical issues of MRS as applied to tumors and metastases in the liver are described as well. In vivo MR spectroscopy of tumors in a metabolically active organ such as the liver has been demonstrated to provide important information on tumor metabolism, but it also is challenging as compared to applications on some other tissues, in particular in humans, mostly because of its abdominal location where movement may be a disturbing factor.

1H magnetic resonance spectroscopy and diffusion weighted imaging findings of medulloblastoma in 3.0T MRI A retrospective analysis of 17 cases

1H magnetic resonance spectroscopy and diffusion weighted imaging features of the cerebellar vermis in 17 medulloblastoma patients were retrospectively analyzed, and 17 healthy volunteers were selected as controls. 1H magnetic resonance spectroscopy showed that in all 17 medulloblastoma patients, N-acetyl aspartate and creatine peaks were significantly decreased, the choline peak was significantly increased, and there was evidence of a myo-inositol peak. Further, 11 patients showed a low taurine peak at 3.4 ppm, five patients showed a lipid peak at 0.9-1.3 ppm, and three patients showed a negative lactic acid peak at 1.33 ppm. Compared with the control group, the ratios of N-acetyl aspartate/choline and N-acetyl aspartate/creatine were significantly decreased, and the ratio of choline/creatine was increased, in medulloblastoma patients. Diffusion weighted imaging displayed hyperintensity and decreased apparent diffusion coefficient in medulloblastoma patients. These findings indicate that 1H magnetic resonance spectroscopy and diffusion weighted imaging are useful for qualitative diagnosis of medulloblastoma.

Serum and urine metabolomic fingerprinting in diagnostics of inflammatory bowel diseases

AIM: To evaluate the utility of serum and urine metabolomic analysis in diagnosing and monitoring of inflammatory bowel diseases (IBD).

Hippocampal and thalamic neuronal metabolism in a putative rat model of schizophrenia°

The transcription factor early growth response protein 3 （EGR3） is involved in schizophrenia. We developed a putative rat model of schizophrenia by transfecting lentiviral particles carrying the Egr3 gene into bilateral hippocampal dentate gyrus. We assessed spatial working memory using the Morris water maze test, and neuronal metabolite levels in bilateral hippocampus and thalamus were determined by 3.0 T proton magnetic resonance spectroscopy. Choline content was significantly greater in the hippocampus after transfection, while N-acetylaspartate and the ratio of N-acetylaspartate to creatine/phosphocreatine in the thalamus were lower than in controls. This study is the first to report evaluation of brain metabolites using 3,0 T proton magnetic resonance spectroscopy in rats transfected with Egr3, and reveals metabolic abnormalities in the hippocampus and thalamus in this putative model of schizophrenia.

Structural Description of Polyaromatic Nucleus in Residue

The proton nuclear magnetic resonance spectroscopy （1H-NMR）, the synchronous fluorescence spectrometry （SFS） and the ruthenium ions catalyzed oxidation （RICO） method were used to determine the chemical structure of polyaromatic nucleus in Oman residue fractions. The results of 1H-NMR analyses showed that the average numbers of aromatic rings in the aromatics, resins and asphaltenes units were 3.2, 5.6 and 8.2, respectively. SFS was used to investigate the distribution of aromatic rings in residue fractions, the main distribution range of aromatic rings in aromatics, resins and asphaltenes were 3 4 rings, 3--5 rings and more than 5 rings, respectively. The aromatic network in residue fractions was oxidized to produce numerous carboxylic acids. The types and content of benzenepolycarboxylic acids, such as phthalic acid, benzenetricarboxylic acids, benzenetetracarboxylic acids, benzenepentacarboxylic acid and benzenehexacarboxylic acid disclosed the condensed types of aromatic nuclei in the core. The biphenyl fraction （BIPH）, the cata-condensed fraction （CATA）, the peri-condensed fraction （PERI） and the condensed index （BCI） were calculated based on the benzenepolycarboxylic acids formed. The results implied that there was less biphenyl type structures in all residue fractions. The aromatics fraction was almost composed of the cata-condensed type system, and the asphaltenes fraction was wholly composed of the peri-condensed type system, while in the resins fraction co-existed the two types, herein the peri-con- densed type was predominant over the cata-condensed type. Based on the analytical results obtained in the study, the components --aromatics, resins and asphaltenes -- were given the likely structural models.

Proton magnetic resonance spectroscopy predicts radiotherapy response and time-to-progression in high-grade gliomas after surgery

Background Reliable early prediction response to therapy and time-to-progression （TTP） remain an important goal of high-grade gliomas （HGGs） research. Proton magnetic resonance spectroscopy （1H-MRS） has been applied with variable success in clinical application, and we hypothesize that 1H-MRS in predictive value should perform well as a marker of TTP in patients treated with radiotherapy （RT） after surgery. Methods 1H-MRS was performed before surgery on 25 patients who had undergone resection of HGGs; then the ratios of lipid/creatine （Lip/Cr） and myo-inositol/creatine （ml/Cr） were determined in the solid tumor. RT response was classified as follows： complete resolution （CR）, partial response （PR）, stable disease （SD）, and progressive disease （PD） by comparison of pre-treatment and post-radiotherapy scans. TTP was defined at the time to radiographic progression by MacDonald criteria. Correlation was evaluated between the ratios of Lip/Cr, ml/Cr and treatment response, TTP. The chi-square test and Pearson correlation test were used for data analyses. Results Multivariate analysis revealed that the prognostic value of spectroscopic variables was independent of age, sex, WHO histologic grade, extent of surgery, and Karnofsky score （KPS）. The correlation between the ratios of lipid/Cr and TTP was significant （r=0.894, P=0.000）, and between the ratios of ml/Cr and TTP was also significant （r=0.891, P=-0.000）. As predicted, RT response correlated significantly with TTP （r=0.59, P=0.002）： median TTP was 49.9 days for patients with PD compared with 202.7 days for SD, 208.0 days for PR, and 234.5 days for CR. Conclusion The ratios of Lip/Cr and ml/Cr of the solid tumor region before surgery could provide important information in predicting RT response and TTP in patients with HGGs treated by radiation alone after surgery.