Diminished Selenium Levels in Hemodialysis and Continuous Ambulatory Peritoneal Dialysis Patients

In this cross-sectional study, selenium (Se) levels in the sera of 35 hemodialysis (HD) patients and 34 patients undergoing continuous ambulatory peritoneal dialysis (CAPD) for more than 3 months were compared with the serum Se levels of 34 healthy volunteers. The observed Se levels of 100.8 ± 51.9 μg/L in the sera of the HD patients and of 65.5 ± 32.1 μg/L in the sera of the CAPD patients were significantly lower than the 134.9 ± 81.2 μg/L of the controls, with p = 0.002 and 0.02, respectively. Furthermore, the Se levels were significantly higher in the HD rather than the CAPD patients (p = 0.01). In the spent dialysate effluent fluid of 32 of the CAPD patients Se was undetectable, in the remaining two CAPD patients the Se levels were 1.9 and 4.6μg/l, respectively. The low Se levels of HD and CAPD patients as compared to healthy persons are attributed to diminished Se retention due to chronic oxidative stress.     

Serum Selenium Levels in Korean Hepatoma Patients

The aim of this study was to determine serum selenium (Se) levels during the development of liver disease as well as the possible Se supplementation benefits in liver disease patients. Serum was collected from 187 patients with liver diseases and 120 normal healthy people living in Seoul. The samples were collected at the Kangnam St. Mary's Hospital College of Medicines, The Catholic University of Korea, in accordance with procedures approved by the Institutional Review Board of the Catholic University of Korea. Serum Se levels were quantified by inductively coupled plasma mass spectrometry and were compared between healthy and liver diseases patients. Se levels were 92.65?±?32.50?μg/l in hepatitis infection, 92.33?±?30.66?μg/l in hepatitis B virus infection and 96.41?±?51.50?μg/l in hepatitis C virus infection, 96.42?±?32.80?μg/l in cirrhosis, and 67.47?±?14.30?μg/l in hepatoma patients. Findings were significantly lower in hepatitis and hepatoma as compared with the healthy participants (P?相似文献   

Altered Serum Selenium and Uric Acid Levels and Dyslipidemia in Hemodialysis Patients Could be Associated with Enhanced Cardiovascular Risk

In the present study, the first objective was to follow up serum selenium (Se) concentrations in 117 hemodialysis patients (HPs) during a 2-year longitudinal study, relating concentrations to biochemical indexes (n?=?6; namely lipoprotein profile, uric acid, and total protein levels). It was also evaluated whether the disease is associated with an enhanced cardiovascular risk. A healthy control group (n?=?50) was also studied. Mean serum Se levels were significantly lower in HPs than in the controls (p?=?0.002); mean levels significantly increased from the first to third blood sampling (p?相似文献   

Serum Gamma-Glutamyltransferase Levels Predict Clinical Outcomes in Hemodialysis Patients

Background

Gamma-glutamyltransferase (GGT) is a biomarker of liver injury. GGT has also been reported to be a marker of oxidative stress and a predictor of mortality in the general population. Hemodialysis (HD) patients suffer from oxidative stress. The aim of our study was to investigate the relationship between serum GGT levels and clinical outcomes in HD patients.

Methods

A total of 1,634 HD patients were enrolled from the Clinical Research Center registry for end-stage renal disease, a prospective cohort in Korea. Patients were categorized into three groups by tertiles of serum GGT levels. The primary outcome was all-cause, cardiovascular, or infection-related mortality and hospitalization.

Results

During the median follow-up period of 30 months, the highest tertile of serum GGT levels had a significantly higher risk for all-cause mortality (hazard ratio (HR) 2.39, 95% confidence interval (CI), 1.55–3.69, P<0.001), cardiovascular mortality (HR 2.14, 95% CI, 1.07–4.26, P = 0.031) and infection-related mortality (HR 3.07, 95% CI, 1.30–7.25, P = 0.011) using tertile 1 as the reference group after adjusting for clinical variables including liver diseases. The highest tertile also had a significantly higher risk for first hospitalization (HR 1.22, 95% CI, 1.00–1.48, P = 0.048) and cardiovascular hospitalization (HR 1.42, 95% CI, 1.06–1.92, P = 0.028).

Conclusions

Our data demonstrate that high serum GGT levels were an independent risk factor for all-cause, cardiovascular, and infection-related mortality, as well as cardiovascular hospitalization in HD patients. These findings suggest that serum GGT levels might be a useful biomarker to predict clinical outcomes in HD patients.     

维持性血液透析患者血清sTWEAK水平与冠状动脉钙化的相关性研究

目的:探讨维持性血液透析患者血清可溶性肿瘤坏死因子样凋亡微弱诱导剂(s TWEAK)水平与冠状动脉钙化的关系。方法:选择维持性血液透析患者60例和健康对照组30例,采用双抗体夹心酶联免疫吸附技术测定其血清s TWEAK水平,采用多层螺旋CT(MSCT)测定其冠状动脉钙化积分(CACs),比较两组的血清s TWEAK水平、CACs,并分析二者的相关性及血液透析患者冠状动脉钙化的危险因素。结果:血液透析患者血清s TWEAK水平显著低于正常对照组,分别为186.23(148.35,220.74)pg/m L和265.13(210.91,298.22)pg/m L,差异有统计学意义(P<0.01)。CACs>400的血液透析患者血清s TWEAK水平显著高于CACs≤400者,分别为220.73(189.70,251.67)pg/m L和146.07(138.43,180.11)pg/m L,差异有统计学意义(P<0.01)。Spearman等级相关分析显示血液透析患者的血清s TWEAK水平与患者的CACs呈明显正相关(r=0.482,P<0.01)。多因素逐步回归分析显示影响血液透析患者CACs严重程度的因素有血清s TWEAK水平、年龄、透析龄、糖尿病(P<0.05)。结论:维持性血液透析患者血清s TWEAK水平较正常人降低,但在血液透析患者s TWEAK范围内,高水平的血清s TWEAK水平与重度冠状动脉钙化相关;血清s TWEAK可能参与了血液透析患者冠状动脉钙化的发生、发展。     

Association of Serum Phosphorus Variability with Coronary Artery Calcification among Hemodialysis Patients

Coronary artery calcification (CAC) is associated with increased mortality in patients on maintenance hemodialysis (MHD), but the pathogenesis of this condition is not well understood. We evaluated the relationship of CAC score (CACs) and variability in serum phosphorus in MHD patients. Seventy-seven adults on MHD at Huashan Hospital (Shanghai) were enrolled in July, 2010. CAC of all the patients were measured by computed tomography and CACs was calculated by the Agatston method at the entry of enrollment. Patients were divided into three categories according to their CACs (0∼10, 11∼400, and >400). Blood chemistry was recorded every 3 months from January 2008 to July 2010. Phosphorus variation was defined by the standard deviation (SD) or coefficient of variation (CV) and it was calculated from the past records. The ordinal multivariate logistic regression analysis was used to analyze the predictors of CAC. The mean patient age (± SD) was 61.7 years (±11.3) and 51% of patients were men. The mean CACs was 609.6 (±1062.9), the median CACs was 168.5, and 78% of patients had CACs more than 0. Multivariate analysis indicated that female gender (OR = 0.20, 95% CI = 0.07–0.55), age (OR = 2.31, 95% CI = 1.32–4.04), serum fibroblast growth factor 23 (OR = 2.25, 95% CI = 1.31–3.85), SD-phosphorus calculated from the most recent 6 measurements (OR = 2.12; 95% CI = 1.23–3.63), and CV-phosphorus calculated from the most recent 6 measurements (OR = 1.90, 95% CI = 1.16–3.11) were significantly and independently associated with CACs. These associations persisted for phosphorus variation calculated from past 7, 8, 9, 10, and 11 follow-up values. Variability of serum phosphorus may contribute significantly to CAC and keeping serum phosphorus stable may decrease coronary calcification and associated morbidity and mortality in MHD patients.     

Decreased Serum Wnt Antagonist Levels in Patients With Active Acromegaly

ObjectiveThe Wnt signaling pathway is an important modulator of bone metabolism. This study aims to clarify the changes in Wnt antagonists in active and biochemically controlled acromegalic patients.MethodsWe recruited 77 patients recently diagnosed with acromegaly. Of those, 41 patients with complete follow-up data were included. Thirty healthy patients matched for age, sex, and body mass index served as controls. At baseline and posttreatment, Wnt antagonists (sclerostin [SOST], dickkopf-related protein 1 [DKK-1], and Wnt inhibitory factor 1 [WIF-1]), bone turnover markers (osteocalcin, procollagen type 1 N-terminal propeptide [P1NP], and C-terminal telopeptide of type 1 collagen [CTX]) and the bone remodeling index were investigated.ResultsAcromegalic patients had higher serum osteocalcin, P1NP, and CTX and a higher bone remodeling index than controls (P < .01). Serum SOST, DKK-1, and WIF-1 levels were significantly decreased in patients compared to controls (all P < .01). Serum SOST and WIF-1 levels were negatively correlated with growth hormone levels; SOST levels were positively correlated with WIF-1. After treatment, serum bone turnover markers and the bone remodeling index decreased, while SOST and WIF-1 significantly increased (P < .05). DKK-1 levels did not change compared to baseline (P > .05). In biochemically controlled patients, SOST and WIF-1 levels and bone turnover markers were restored and did not differ from those of the control participants (all P > .05).ConclusionPatients with active acromegaly exhibited significantly decreased Wnt antagonist levels. The reduction in Wnt antagonists is a compensatory mechanism to counteract increased bone fragility in active acromegaly.     

Levels of Selenium, Zinc, Copper, and Cardiac Troponin I in Serum of Patients with Acute Coronary Syndrome

The aim of this study was to assess the levels of selenium (Se), zinc (Zn), copper (Cu), and troponin I (TnI) in patients with acute coronary syndrome (ACS) on admission to our emergency department in comparison to healthy control subjects. Patients with diagnosed ACS (n?=?100) were included in the study group. Control subjects (n?=?100) were selected from healthy volunteers in the same age range. Venous blood samples were obtained to evaluate the levels of Se, Zn, Cu, and TnI (on admission for the ACS group). Serum Se, Zn, and Cu levels were significantly less in the ACS group compared to the control group (p <0.001, p <0.01, and p <0.001, respectively). The serum TnI level was significantly greater in the ACS group compared to the control group (p <0.05). The serum Se level in the ACS group correlated significantly with the TnI level (r?=??0.211, p?=?0.035). These results indicate that Se, Zn, and Cu deficiencies may be risk factors for ACS, and a decreased serum Se level in patients with ACS might reflect the degree of myocardial necrosis.     

Serum Selenium Levels in Patients With Graves Disease With or Without Thyroid Ophthalmopathy

BackgroundGraves disease is one of the most common autoimmune thyroid diseases. Thyroid has the highest concentration of selenium (Se) in the body. Se plays a crucial role in the functioning of some thyroid enzymes; however, there are controversial results regarding the administration of serum Se levels in patients with Graves disease.MethodsIn this study, patients with Graves disease with orbitopathy (GO group) or without orbitopathy (GD group) were recruited. Healthy individuals without a history of any disease were enrolled as the control group. Serum Se and thyroid hormone levels, including T3, T4, and thyroid-stimulating hormone (TSH), were measured using atomic absorption and radioimmunoassay techniques, respectively.ResultsIn this cross-sectional study, 60 and 56 patients and 58 healthy subjects were included in the GO, GD, and control groups. Serum Se levels in the GO, GD, and control groups were 94.53 ± 25.36 μg/dL, 96.82 ± 30.3 μg/dL, and 102.55 ± 16.53 μg/dL, respectively (P = .193). There was a reverse association between the serum Se level and thyroid hormones, including T3, T4, and TSH, in the GO group. However, serum Se levels exhibited a significant reverse association with T4 and TSH hormones but not with T3 in the GD group.ConclusionOur results showed no significant differences in the serum Se levels in the GO and GD groups compared with that in the control group. In addition, we did not detect any significant difference in the serum Se levels between the GO and GD groups.     

Quantitative Analyses of Schizophrenia-Associated Metabolites in Serum: Serum D-Lactate Levels Are Negatively Correlated with Gamma-Glutamylcysteine in Medicated Schizophrenia Patients

The serum levels of several metabolites are significantly altered in schizophrenia patients. In this study, we performed a targeted analysis of 34 candidate metabolites in schizophrenia patients (n = 25) and compared them with those in age- and gender-matched healthy subjects (n = 27). Orthogonal partial least square-discriminant analysis revealed that complete separation between controls and patients was achieved based on these metabolites. We found that the levels of γ-glutamylcysteine (γ-GluCys), linoleic acid, arachidonic acid, D-serine, 3-hydroxybutyrate, glutathione (GSH), 5-hydroxytryptamine, threonine, and tyrosine were significantly lower, while D-lactate, tryptophan, kynurenine, and glutamate levels were significantly higher in schizophrenia patients compared to controls. Using receiver operating characteristics (ROC) curve analysis, the sensitivity, specificity, and the area under curve of γ-GluCys, a precursor of GSH, and D-lactate, a terminal metabolite of methylglyoxal, were 88.00%, 81.48%, and 0.8874, and 88.00%, 77.78%, and 0.8415, respectively. In addition, serum levels of D-lactate were negatively correlated with γ-GluCys levels in patients, but not in controls. The present results suggest that oxidative stress-induced damage may be involved in the pathogenesis of schizophrenia.     

Fractional Flow Reserve Is Not Associated with Inflammatory Markers in Patients with Stable Coronary Artery Disease

Background

Atherosclerosis is an inflammatory condition and increased blood levels of inflammatory biomarkers have been observed in acute coronary syndromes. In addition, high expression of inflammatory markers is associated with worse prognosis of coronary artery disease. The presence and extent of inducible ischemia in patients with stable angina has previously been shown to have strong prognostic value. We hypothesized that evidence of inducible myocardial ischemia by local lesions, as measured by fractional flow reserve (FFR), is associated with increased levels of blood based inflammatory biomarkers.

Methods

Whole blood samples of 89 patients with stable angina pectoris and 16 healthy controls were analyzed. The patients with stable angina pectoris underwent coronary angiography and FFR of all coronary lesions.We analyzed plasma levels of cytokines IL-6, IL-8 and TNF-α and membrane expression of Toll-like receptor 2 and 4, CD11b, CD62L and CD14 on monocytes and granulocytes as markers of inflammation.Furthermore, we quantified the severity of hemodynamically significant coronary artery disease by calculating Functional Syntax Score (FSS), an extension of the Syntax Score.

Results

For the majority of biomarkers, we observed lower levels in the healthy control group compared with patients with stable angina who underwent coronary catheterization.We found no difference for any of the selected biomarkers between patients with a positive FFR (≤0.75) and negative FFR (>0.80). We observed no relationship between the investigated biomarkers and FSS.

Conclusion

The presence of local atherosclerotic lesions that result in inducible myocardial ischemia as measured by FFR in patients with stable coronary artery disease is not associated with increased plasma levels of IL-6, IL-8 and TNF-α or increased expression of TLR2 and TLR4, CD11b, CD62L and CD14 on circulating leukocytes.     

冠心病患者介入治疗前后血清IL-18、sCD40L 和hs-CRP 水平的 变化及其意义

目的:探讨冠心病患者血清白介素18(Interleukin-18,IL-18)、白细胞分化抗原40配体(CD40L)、及高敏C反应蛋白(hs-CRP)水平在经皮冠状动脉介入术治疗前后的变化和意义。方法:选择经冠状动脉造影确诊的冠心病患者85例,根据病变程度分为单支病变组(n=32)、双支病变组(n=28)和多支病变组(n=25),采用双抗体夹心ELISA法测定PCI术前术后血清IL-18、CD40L和hs-CRP水平。结果:血清IL-18水平测定结果:多支病变组高于双支病变组,双支病变组高于单支病变组;支架置入术后显著高于术前,差异均有统计学意义(P<0.01)。血清CD40L水平测定结果:多支病变组高于双支病变组和单支病变组,差异均有统计学意义(P<0.01),双支病变组与单支病变组间差异无统计学意义(P>0.05);支架置入术后较术前显著升高,差异有统计学意义(P<0.01)。血清hs-CRP水平测定结果:多支病变组高于双支病变组,双支病变组高于单支病变组;支架置入术后显著高于术前,差异均有统计学意义(P<0.01)。结论:冠心病患者血清IL-18、CD40L和hs-CRP与冠脉病变程度密切相关,介入治疗可使冠心病患者血清IL-18、CD40L和hs-CRP水平升高,监测血清中IL-18、CD40L和hs-CRP水平变化可了解治疗效果和炎症程度。     

冠心病患者介入治疗前后血清IL-18、sCD40L和hs-CRP水平的变化及其意义

目的：探讨冠心病患者血清白介素18（Interleukin-18,IL-18）、白细胞分化抗原40配体（CD40L）、及高敏C反应蛋白（hs-CRP）水平在经皮冠状动脉介入术治疗前后的变化和意义。方法：选择经冠状动脉造影确诊的冠心病患者85例,根据病变程度分为单支病变组（n=32）、双支病变组（n=28）和多支病变组（n=25）,采用双抗体夹心ELISA法测定PCI术前术后血清IL-18、CD40L和hs-CRP水平。结果：血清IL-18水平测定结果：多支病变组高于双支病变组,双支病变组高于单支病变组;支架置入术后显著高于术前,差异均有统计学意义（P〈0.01）。血清CD40L水平测定结果：多支病变组高于双支病变组和单支病变组,差异均有统计学意义（P〈0.01）,双支病变组与单支病变组间差异无统计学意义（P〉0.05）;支架置入术后较术前显著升高,差异有统计学意义（P〈0.01）。血清hs-CRP水平测定结果：多支病变组高于双支病变组,双支病变组高于单支病变组;支架置入术后显著高于术前,差异均有统计学意义（P〈0.01）。结论：冠心病患者血清IL-18、CD40L和hs-CRP与冠脉病变程度密切相关,介入治疗可使冠心病患者血清IL-18、CD40L和hs-CRP水平升高,监测血清中IL-18、CD40L和hs-CRP水平变化可了解治疗效果和炎症程度。     

Increased Serum Al Levels in Hemodialysis Patients Kept Enhanced during a 2-Year Prospective Study

The regulation of mineral homeostasis is altered in hemodialysis patients with renal insufficiency, producing increased risk for secondary diseases like cardiovascular ones. We hypothesized that risen serum aluminum (Al) concentration in hemodialysis patients kept enhanced during a 2-year longitudinal study is associated with enhanced cardiovascular risk and influenced by medical treatments. This study reports the prospective monitoring of serum Al levels in six-monthly samplings over 2 years in 116 hemodialysis patients and a control group of 50 healthy adults. The influence of other factors like sex, age, kidney transplant, disease etiology, and drug consumption was also considered. At each sampling, serum Al levels were significantly higher in the patients than in the healthy controls (P < 0.05). Levels in the patient group were statistically significantly lower at the third and fourth versus first and second samplings, which may be related to Al accumulation in tissues. Increased Al levels in patients were positively and significantly related to serum calcium (Ca) and uric acid levels. Serum Al concentrations were significantly lower in patients receiving vasodilators and diuretics. Higher serum Al levels in hemodialyzed patients administered with phosphate binders or anti-hyperkalemics are attributable to their usual Al salt content. The consumption of antianemic drugs increases Al absorption by forming more bioavailable complexes with the compounds in these drugs. In conclusion, this is the first study to indicate that cardiovascular problems associated with elevated serum Al levels in hemodialysis patients may be in part mitigated by administrating vasodilators and diuretics, which reduce these levels.     

Effects of Different Medical Treatments on Serum Copper,Selenium and Zinc Levels in Patients with Rheumatoid Arthritis

The aim of the present study was to measure the changes in serum selenium, zinc, and copper in patients being treated for rheumatoid arthritis. Thirty-two patients and 52 healthy controls were included in the study. The copper level was higher and those of selenium and zinc were lower in the patients relative to controls. Treatment with methotrexate elevated the zinc levels, but not zinc and selenium. Treatments with salazopyrin, corticosteroids, chloroquine, and non-steroidal anti-inflammatory drugs did not change the levels of any of the elements studied. The decrease in zinc and selenium levels and elevation in copper levels observed in the patients probably resulted from the defense response of organism and are mediated by inflammatory-like substances.     

血清chemerin 水平与代谢综合征患者合并冠心病的相关性研究

目的:旨在探讨血清脂肪因子chemerin水平与代谢综合征患者合并冠心病的相关性。方法:共纳入116名代谢综合征患者,将所有患者分为两组,合并冠心病组(CAD+,n=47)及未合并冠心病组(CAD-,n=69),使用酶联免疫吸附(ELISA)法测量每组血清的血清chemerin水平。结果:CAD+组患者的血清chemerin水平较CAD-组患者显著升高(129.83±29.18 vs 94.01±23.54 ng/mL;P<0.01),多元Logistic回归分析结果显示血清chemerin水平与代谢综合征患者合并冠心病存在独立相关性(优势比1.565,95%可信区间1.104-2.876;P<0.05)。结论:血清chemerin水平是代谢综合征患者合并冠心病的独立危险因子,血清chemerin可能是预测代谢综合征患者发生冠心病风险的重要的生物学标记物。     

Coronary Flow Reserve in Pregnant Rats with Increased Left Ventricular Afterload

Background

Coronary flow reserve (CFR) is used as a measure of coronary endothelial function. We investigated the effect of increased afterload on CFR of pregnant and non-pregnant rats.

Methods

Afterload increase in Wister rats (both pregnant and non-pregnant) was achieved by the infusion of angiotensin II (Ang II) for ∼10 days or by subjecting them to transverse aortic constriction (TAC) for ∼14 days. Control groups were infused with 0.9% NaCl or had sham surgery, respectively. In pregnant rats, the experiments were performed close to term gestation. Doppler velocity waveforms of the left main coronary artery were recorded using a high resolution ultrasound imaging system (Vevo 770, VisualSonics, Canada) at baseline while the animals were anesthetized with 1.5% inhaled isoflurane, and during maximal coronary dilatation obtained by the inhalation of 3.5% of isoflurane. CFR was calculated as the ratio between the peak coronary flow velocities (CFR_peak) and the velocity-time integrals (CFR_VTI) recorded at hyperemia and at baseline.

Results

CFR could be calculated in 60 of 75 (80%) animals. There were no differences in CFR between intervention and control groups irrespective of whether afterload was increased by Ang II or TAC. In the TAC-study CFR_peak (1.54±0.07 vs 1.85±0.17; p = 0.03) was decreased in pregnant compared to non-pregnant shams. When sham animals from both studies were pooled together both CFR_peak (1.42±0.07 vs 1.86±0.16; p = 0.005) as well as CFR_VTI (1.45±0.07 vs 1.78±0.12; p = 0.03) were significantly lower in pregnant rats compared to non-pregnant.

Conclusions

CFR can be measured non-invasively in rats using Doppler echocardiography and high concentrations of inhaled isoflurane as a coronary vasodilator. In pregnant rats, CFR is reduced close to term. CFR is not affected by increased left ventricular afterload caused by chronic Ang II infusion or TAC.     

血液透析与血液灌流对终末期糖尿病肾病患者胰岛素抵抗及血清炎症因 子水平的影响

目的:探讨血液透析联合血液灌流治疗终末期糖尿病肾病的疗效以及对患者胰岛素抵抗及血清炎症因子水平的影响。方法:选择2013年7月-2015年7月在我院接受治疗的100例终末期糖尿病肾病患者作为研究对象。根据治疗方法不同,将所选研究对象分为研究组和对照组。研究组采用血液透析联合血液灌流治疗,对照组采用血液透析联合血液透析滤过治疗。观察并比较两组患者治疗前后胰岛素抵抗程度及血清C反应蛋白(CRP),肿瘤坏死因子-α(TNF-α)及白介素-6(IL-6)水平的变化情况。结果:治疗前,两组患者FBG、FINS、Homa-IR、CRP、TNF-α及IL-6水平比较差异均无统计学意义(P0.05);与治疗前比较,两组患者治疗后FBG、FINS、Homa-IR、CRP、TNF-α及IL-6水平均显著降低,差异具有统计学意义(P0.05),且研究组患者治疗后FBG、FINS、Homa-IR、CRP、TNF-α及IL-6水平均明显低于对照组,差异具有统计学意义(P0.05)。结论:与血液透析联合血液透析滤过方法比较,血液透析联合血液灌流治疗能够更有效的改善ESDN患者胰岛素抵抗程度,降低炎症因子水平,值得临床进一步推广应用。     

Decreased Cerebrospinal Fluid Glutamine Levels in Patients with Benign Brain Tumors

Abstract: CSF glutamine concentrations were studied in 12 patients with benign brain tumors (meningioma, craniopharyngioma, or osteofibroma), 12 patients with malignant brain tumors (astrocytoma, medulloblastoma, pinealoblastoma, or chondrosarcoma), 9 patients with non-cerebral tumors, and a reference group of 24 patients. The mean ± SD levels in the benign tumor group (424 ± 124 μ M ) were significantly lower (p < 0.0004) than those in the reference group (642 ± 195 μ M ). There was no significant difference between the CSF glutamine concentrations in the malignant cerebral tumor group (643 ± 210 μ M ) or noncerebral tumor group (599 ± 127 μ M ) and those in the reference group. In patients with benign brain tumors there was indication of an inverse linear relationship between the logarithm of CSF glutamine concentration and tumor diameter.