Evaluation and application of a high performance liquid chromatographic method for prilocaine analysis in human plasma.

BACKGROUND: Prilocaine, a local anesthetic of the amide type, is frequently applied in substantial doses during tumescent liposuction. Although it cannot be excluded that the subcutaneously infiltrated narcotic may enter the circulation and trigger adverse systemic reactions, prilocaine plasma levels have rarely been measured during routine tumescent surgery. We established and evaluated a high performance liquid chromatography (HPLC) method for analysis of this narcotic and used it to measure the drug in plasma samples drawn in the course of tumescent liposuction with prilocaine local anesthesia. METHODS: After approval by the local ethics committee and written informed consent, 283 heparin plasma samples were collected from 132 patients during and about 6, 12, and 24 hours after tumescent liposuction with prilocaine infused at doses of 19 +/- 5 mg/kg body weight. Calibrators and controls were prepared by spiking blank plasma with prilocaine. Following addition of internal standard and sodium hydroxide, plasma was extracted with diisopropyl ether. For HPLC analysis, dried extracts were dissolved in methanol - 4.35 mmol/L ammonium phosphate, pH7.0, (60:40 v/v) and applied to a Synergy 4 microm Fusion-RP column (250 x 4.6 mm) rinsed with the same buffer. Analytes were detected by absorption at 237 nm. For liquid chromatography mass spectrometry (LC-MS), extracts were dissolved in acetonitrile - 2 mmol/L ammonium acetate - formic acid (5:95:0.2 v/v/v), applied to a Synergy 4 microm Polar-RP column (75 x 2 mm), and eluted with a gradient of acetonitrile in 2 mmol/L ammonium acetate - formic acid. Analytes were detected by an ion trap mass spectrometer with electrospray ionization run in a MS/MS mode. RESULTS: In the HPLC assay established, prilocaine and the internal standard lidocaine eluted at about 14 and 25 minutes, respectively. The limit of detection of prilocaine was 0.002 mg/L, the measurable range extended to 30 mg/L. At prilocaine concentrations between 0.08 and 10.0 mg/L, inter-assay coefficients of variation of 6.2 to 9.9% were obtained. Analyses of plasma pools spiked with variable amounts of prilocaine showed recoveries of 91-101%. Results measured in 20 plasma samples by both HPLC and an independent LC-MS assay agreed acceptably (Y(HPLC) = 0.07 + 1.19x(LC-MS), R 0.98). Prilocaine plasma concentrations measured by HPLC in 132 plasma samples drawn in the late phase of liposuction ranged between 0.01 and 32.0 mg/L, roughly one third of all samples exhibiting levels above 5 mg/L. About 6 hours later, prilocaine levels measured in 46 plasma samples were lower (0.13 - 1.56 mg/L) and decreased further in the evening of the operative day (n = 49, 0.10 - 0.62 mg/L) and on the morning of the first postoperative day (n = 55, 0.03 - 0.25 mg/L). CONCLUSIONS: An HPLC method for determination of prilocaine was established and successfully applied to analysis of this drug in human plasma. Our results clearly indicate that during tumescent liposuction a significant portion of the subcutaneously infiltrated prilocaine enters the circulation, resulting in potentially harmful blood levels in about one third of the patients studied. 6 hours after liposuction, however, all samples exhibited prilocaine plasma levels far below a critical concentration and these levels further decreased in the evening of the day of treatment and on the next morning.

Toward standardized high-throughput serum diagnostics: multiplex-protein array identifies IL-8 and VEGF as serum markers for colon cancer.

Development and progression of colon cancer may be related to cytokines. Cytokines with diagnostic value have been identified individually but have not been implemented into clinical praxis. Using a multiplex protein array, the authors explore a panel of cytokines simultaneously and compared its performance to carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA 19-9). Serum concentrations of 12 cytokines were simultaneously determined by multiplex biochip technology in 50 colon cancer patients and 50 healthy controls. Serum levels of interleukin-8 (IL-8) and CEA were significantly higher in cancer patients than in healthy controls. Areas under the receiver operating characteristic curves (AUCs) were largest for IL-8, followed by CEA, vascular endothelial growth factor (VEGF), and CA 19-9. Analyses regarding marker combinations showed an advantage over single marker performance for CEA, VEGF, and CA 19-9 but not for IL-8. Multiplex biochip array technology represents a practical tool in cytokine and cancer research when simultaneous determination of different biomarkers is of interest. The results suggest that the assessment of IL-8, CEA, VEGF, and possibly CA 19-9 serum levels could be useful for colon cancer screening with the potential of also detecting early stage tumors. Further validation studies using these and additional markers on a multiplex array format are encouraged.

Major depression, borderline personality disorder, and visceral fat content in women.

Major depressive disorder (MDD) is associated with increased volumes of visceral fat and a high prevalence of the metabolic syndrome. In turn, affective disorders are frequently found in patients with borderline personality disorder (BPD). It is therefore unclear whether BPD per se may influence body composition. In order to clarify a potential relationship between BPD and body composition, we measured visceral fat content (VFC) in young depressed women with and without comorbid BPD and related this parameter to various features of the metabolic syndrome. Visceral fat content was measured by magnetic resonance imaging in 22 premenopausal women with MDD only, in 44 women with comorbid MDD and BPD, in 12 female BPD patients without MDD, and in 34 healthy women (CG). Data showed that depressed women without comorbid BPD had a 335% higher VFC and women with comorbid BPD had a 250% higher VFC than the CG women. When controlling for age, data showed significant effects of MDD on VFC (F = 8.4; P = 0.005). However, BPD, with or without MDD, was not related to VFC. Young depressed women with and without comorbid BPD display increased visceral fat content when compared to control subjects and may therefore constitute a risk group for the development of the metabolic syndrome. BPD per se is not an additive risk factor in this context.

Propofol in bronchoalveolar lavage during anaesthesia.

BACKGROUND: The lung protecting effect of propofol requires methods to measure the propofol concentration of the epithelial line fluid covering the alveolar surface. We hypothesized that (1) propofol can be determined in bronchoalveolar lavage (BAL) by reversed phase high performance liquid chromatography with fluorescence detection. (2) Positive end-expiratory pressure (PEEP) ventilation may have an effect on propofol concentration in BAL (cpB). METHODS: 76 surgical patients were investigated after institutional review board approval. After criteria-based exclusion 45 samples were included. For group I (n=15) BAL was performed directly after induction, for group Z (n=15, PEEP=0 cm H2O) and P (n=15, PEEP=10 cm H2O) at the end of anaesthesia. BAL and plasma samples were analysed for propofol by reversed phase high performance liquid chromatography with fluorescence detection. Data from all groups were compared by non-parametric Mann-Whitney U-test. RESULTS: Propofol can be detected in BAL. CpB varied between 23 and 167 µg l⁻¹ in all groups. Patients ventilated with PEEP (group P) showed significantly higher cpB (median 74.5 µg l⁻¹) compared to those immediately after induction of anaesthesia (median 42.0 µg l⁻¹) (group I), but not to those ventilated without PEEP in group Z (median 52.5 µg l⁻¹). CONCLUSION: Epithelial line fluid, sampled by BAL, can be used to determine cpB by reversed phase high performance liquid chromatography with fluorescence detection. Continuous propofol infusion and PEEP ventilation may have an effect on cpB.

Preoperative cerebral oxygen saturation and clinical outcomes in cardiac surgery.

BACKGROUND: The current study was designed to determine the relation between preoperative cerebral oxygen saturation (Sco2), variables of cardiopulmonary function, mortality, and morbidity in a heterogeneous cohort of cardiac surgery patients. METHODS: In this study, 1,178 consecutive patients scheduled for on-pump surgery were prospectively studied. Preoperative Sco2, demographics, N-terminal pro-B-type natriuretic peptide, high-sensitive troponin T, clinical outcomes, and 30-day and 1-yr mortality were recorded. RESULTS: Median additive EuroSCORE was 5 (range: 0-19). Thirty-day and 1-yr mortality and major morbidity (at least two major complications and/or a high-dependency unit stay of at least 10 days) were 3.5%, 7.7%, and 13.3%, respectively. Median minimal preoperative oxygen supplemented Sco2 (Sco2min-ox) was 64% (range: 15-92%). Sco2min-ox was correlated (all: P value <0.0001) with N-terminal pro-B-type natriuretic peptide (ρ: -0.35), high-sensitive troponin T (ρ: -0.28), hematocrit (ρ: 0.34), glomerular filtration rate (ρ: 0.19), EuroSCORE (τ: 0.20), and left ventricular ejection fraction class (τ: 0.12). Thirty-day nonsurvivors had a lower Sco2min-ox than survivors (median 58% [95% CI, 50.7-62%] vs. 64% [95% CI, 64-65%]; P < 0.0001). Receiver-operating curve analysis of Sco2min-ox and 30-day mortality revealed an area-under-the-curve of 0.71 (95% CI, 0.68-0.73%; P < 0.0001) in the total cohort and an area-under-the-curve of 0.77 (95% CI, 0.69-0.86%; P < 0.0001) in patients with a EuroSCORE more than 10. Logistic regression based on different EuroSCORE categories (0-2; 3-5, 6-10, >10), Sco2min-ox, and duration of cardiopulmonary bypass showed that a Sco2min-ox equal or less than 50% is an independent risk factor for 30-day and 1-yr mortality. CONCLUSIONS: Preoperative Sco2 levels are reflective of the severity of cardiopulmonary dysfunction, associated with short- and long-term mortality and morbidity, and may add to preoperative risk stratification in patients undergoing cardiac surgery.

Time course of ethanol and propofol exhalation after bolus injection using ion molecule reaction-mass spectrometry.

The transit of ethanol from blood to breath gas is well characterised. It is used for intraoperative monitoring and in forensic investigations. A further substance, which can be measured in breath gas, is the phenol propofol. After a simultaneous bolus injection, the signals (time course and amplitude) of ethanol and propofol in breath gas were detected by ion molecule reaction-mass spectrometry (IMR-MS) and compared. After approval by the regional authorities, eight pigs were endotracheally intubated after a propofol-free induction with etomidate. Boluses of ethanol (16 µg/kg) and propofol (4 or 2 mg/kg) were infused alone and in combination. For both substances, breath gas concentrations were continuously measured by IMR-MS; the delay time, time to peak and amplitude were determined and compared using non-parametric statistic tests. IMR-MS allows a simultaneous continuous measurement of both substances in breath gas. Ethanol appeared (median delay time, 12 vs 29.5 s) and reached its peak concentration (median time to peak, 45.5 vs 112 s) significantly earlier than propofol. Time courses of ethanol and propofol in breath gas can be simultaneously described with IMR-MS. Differing pharmacological and physicochemical properties of the two substances can explain the earlier appearance and time to peak of ethanol in breath gas compared with propofol.

Urinary ethyl glucuronide (EtG) and ethyl sulphate (EtS) assessment: valuable tools to improve verification of abstention in alcohol-dependent patients during in-patient treatment and at follow-ups.

AIMS: The aims of this study were (i) to assess the effect of additional urinary ethyl glucuronide (EtG) and ethyl sulphate (EtS) assessment on diagnosed relapse rates in detoxified alcohol-dependent patients; and (ii) to compare dropout rates between EtG- and EtS-negative and -positive patients. DESIGN: Two studies on detoxified alcohol-dependent patients. If patients had no indication of relapse they were asked for a urinary sample at discharge from in-patient treatment 3, 6 and 12 weeks after discharge (study 1) and 1, 3 and 6 weeks after discharge (study 2), respectively. SETTING: Department of Psychiatry, University of Luebeck, Germany. PARTICIPANTS: A total of 107 and 32 detoxified alcohol-dependent patients having participated in a 3-week in-patient motivation enhancement programme. MEASUREMENT: Personal interviews, breathalyzer tests, assessment of urinary EtG and EtS with liquid chromatography-tandem mass spectrometry (LC-MS/MS analysis). FINDING: Urinary EtG and EtS were always positive at the same time. In the first study 13.5% of the patients were already positive before being discharged from hospital. At the follow-ups 3, 6 and 12 weeks after discharge 12.2, 19.4 and 28.0%, respectively, of the patients coming to the follow-up and denying relapse were positive on urinary EtG and EtS. In the second study, of those patients showing up for follow-up after 1 week and denying relapse, EtG and EtS were positive in four cases (17.4%). Only one EtG- and EtS-positive relapser (3.1%) came to the next follow-ups. In both studies the rates of detected relapses were significantly higher for early follow-ups if urinary EtG and EtS results were considered additionally. Dropout rates until the next follow-up were significantly higher among positive than EtG- and EtS-negative patients. CONCLUSION: Urinary EtG and EtS improve verification of abstinence in studies of alcohol-dependent patients.

Angiogenic factors in patients with current major depressive disorder comorbid with borderline personality disorder.

BACKGROUND: Major depression has been associated with endocrine and immune alterations, in particular a dysregulation of the hypothalamus-pituitary-adrenal system with subsequent hypercortisolism and an imbalance of pro- and anti-inflammatory cytokines. Recent studies suggest that vascular endothelial growth factor (VEGF), a cytokine involved in angiogenesis and neurogenesis, may also be dysregulated during stress and depression. These observations prompted us to examine VEGF and other angiogenic factors in patients with major depressive disorder. METHODS: Twelve medication-free female patients with a major depressive episode in the context of borderline personality disorder (MDD/BPD) and twelve healthy women were included. Concentrations of VEGF, VEGF receptors 1 and 2, basic fibroblast growth factor-2 (FGF-2), hepatocyte growth factor (HGF), angiopoetin-2, interleukin-8 (IL-8) and transforming growth factor-beta1 (TGF-beta1) were determined from serum profiles. RESULTS: Increased concentrations of VEGF and FGF-2 were found in MDD/BPD patients compared to the healthy comparator group. No group differences were found concerning the other angiogenic factors examined. CONCLUSION: Depressive episodes in the context of borderline personality disorder may be accompanied by increased serum concentrations of VEGF and FGF-2. Similar findings have been observed in patients with major depression without a borderline personality disorder. A dysregulation of angiogenic factors may be another facet of the endocrine and immunologic disturbances frequently seen in patients with depressive episodes.

Hemoximetry as the "gold standard"? Error assessment based on differences among identical blood gas analyzer devices of five manufacturers.

BACKGROUND: The calibration and testing procedures of a pulse oximeter with arterial blood samples from healthy subjects are based on reference values from the hemoximeter. There are no tests to identify the accuracy of the reference devices. Because of this limitation and since the true values of oxygen saturation (sO2 in %) in blood samples were not known, we used the differences between two identical devices, A and B, for error assessment. METHODS: Two identical devices, A and B, from five leading manufacturers were investigated. Seventy-two arterial blood samples from 12 healthy volunteers at three different levels of saturation between 100% and 70% sO2 were randomly evaluated by the test systems. RESULTS: The observed differences (Delta) between Devices A and B, as a measure for the error of the hemoximeters, increased significantly with all manufacturers from level 97 (Deltamin, -0.9%; Deltamax, 2.6%) to 85 (Deltamin, -2.4%; Deltamax, 4.3), this effect was even stronger between levels 97 and 75 (Deltamin, -4.6%; Deltamax, 4.3%). A variance proportion analysis revealed the concentration of the reduced hemoglobin as the main error source for sO2 measurements. Independent from the sO2 levels there were also significant differences for the carboxy hemoglobin concentration in the range of 0%-4% and for the methemoglobin concentration in the range of 0%-1%. CONCLUSIONS: The variance of sO2 measurements between identical devices increased significantly when saturation decreased from the normal level of 97% to the hypoxemic levels of 85% and 75%.

Differences of propofol concentrations in mammalian whole blood and in corresponding plasma samples analyzed by high performance liquid chromatography.

BACKGROUND: In preparation for a study of the pharmacokinetics and elimination of propofol, a frequently used intravenous narcotic, we sought for a simple but accurate method for determining the drug in biological fluids from various mammalian species. MATERIALS AND METHODS: We established an isocratic high performance liquid chromatography (HPLC) assay with fluorimetric detection for quantification of propofol, studied the analytical characteristics of the method, and measured the narcotic in heparinized whole blood and corresponding plasma samples drawn from 5 subjects each of humans, pigs, sheep and goats prior to and after 10 minutes of constant infusion of propofol. RESULTS: Following protein precipitation with methanol, propofol was quantified in the alcoholic phase. With 30 microl extract, lower limits of detection and quantification of propofol were 2 and 10 microg I(-1), the measurable range extended to 8000 microg I(-1). Intra- and inter-assay CVs tested at propofol concentrations between 40 and 3000 microg I(-1) were < 3% and < 8%, respectively. Propofol levels ranged from 900 to 10,000 microg I(-1) after 10 minutes of drug infusion; among the animals treated with identical doses, pigs exhibited the highest and sheep the lowest circulating propofol concentrations. CONCLUSIONS: Analysis of propofol by the HPLC method described is highly practicable, sensitive and specific. Propofol concentrations measured in heparinized blood and corresponding plasma samples differ slightly; in addition to inter-individual variations, species-specific differences in the drug's disposition between plasma and blood cells were observed.

Bone mineral density, bone turnover, and osteoprotegerin in depressed women with and without borderline personality disorder.

OBJECTIVE: Low bone mineral density has repeatedly been reported in patients with major depressive disorder (MDD), and MDD has been discussed as a risk factor for the development of osteoporosis. MDD in young adults often occurs in the context of borderline personality disorder (BPD), and both MDD and BPD have been associated with a dysregulation of the hypothalamic-pituitary-adrenal system and subsequent hypercortisolemia. To date, it is unclear whether comorbid BPD in depressed patients modulates the extent of bone mass reduction. Therefore, we examined bone density, markers of bone turnover, and proinflammatory cytokines in depressed patients with and without BPD. Patients with BPD alone and healthy women served as comparison groups. METHOD: Twenty-four patients with MDD and 23 patients with comorbid MDD and BPD were included. Sixteen patients with BPD and 20 healthy women of similar body mass index served as the comparison group. BMD was assessed by means of dual-energy x-ray absorptiometry. Markers of bone turnover, endocrine and immune parameters were determined. For data analysis, the group of depressed patients without comorbid BPD was divided according to age into two groups (younger depressed patients with a mean age of 30 years and older patients with a mean age of 42.9 years). RESULTS: BMD at the lumbar spine was significantly reduced in a) depressed women with comorbid BPD (mean age, 28.6 years) and in b) older depressed patients without BPD (mean age, 42.9 years). Osteocalcin, a marker of osteoblastic activity, and crosslaps, a marker of bone loss, were significantly different between the study groups. Tumor necrosis factor-alpha was increased in depressed patients when compared with healthy women. Furthermore, TNF-alpha was positively correlated with serum crosslaps, a marker for osteoclastic activity. CONCLUSION: Depression is associated with reduced bone mass, in particular in patients with comorbid BPD. Possible factors contributing to BMD reduction include endocrine and immune alterations associated with either MDD or BPD. We conclude from our data that a history of MDD with and without comorbid BPD should be considered as a risk factor in clinical assessment instruments for the identification of persons prone to osteoporosis.

Discontinuous monitoring of propofol concentrations in expired alveolar gas and in arterial and venous plasma during artificial ventilation.

BACKGROUND: Analyzing propofol concentration in expired alveolar gas (cPA) may be considered as a convenient, noninvasive method to follow the propofol concentration in plasma (cPPL). In the current study, the authors established procedures to measure cPA and cPPL for the assessment of their relation in two animal models during anesthesia. METHODS: Expired alveolar gas and mixed venous and arterial blood were simultaneously sampled during continuous application of propofol for general anesthesia to three goats and three pigs. Propofol infusion rates were varied to modify plasma concentrations. cPA, sampled cumulatively over several respiratory cycles, was quantified by thermal desorption gas chromatography-mass spectrometry. cPPL was determined using reversed phase high-performance liquid chromatography with fluorescence detection. RESULTS: cPA ranged from 0 to 1.4 and from 0 to 22 parts per billion in goats and pigs, respectively, at cPPL of 0-8 microg/ml. The relation between cPA and cPPL was linear; however, the slopes of the regression lines varied between animals. CONCLUSION: Propofol can be quantified in expired alveolar gas. The results stress the role of marked species-specific variability.

Cortisol, the cortisol-dehydroepiandrosterone ratio, and pro-inflammatory cytokines in patients with current major depressive disorder comorbid with borderline personality disorder.

BACKGROUND: Major depression in young women is often comorbid with borderline personality disorder (BPD); however, adrenal steroids and pro-inflammatory cytokines in patients with comorbid current major depressive disorder and BPD (MDD/BPD) have not been systematically examined. Therefore, our study aimed at examining serum profiles of cortisol, cytokines, and the cortisol/dehydroepiandrosterone (cortisol/DHEA) ratio in MDD/BPD patients and a healthy comparison group. METHODS: Twelve medication-free female patients with MDD/BPD and 12 healthy women were included. Serum profiles of cortisol, DHEA, tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and interleukin-1beta were sampled, and the molar cortisol/DHEA ratio was determined. RESULTS: Concentrations of serum cortisol, TNF-alpha, and IL-6, as well as the cortisol/DHEA ratios were significantly increased in MDD/BPD patients as compared with the healthy comparison group. CONCLUSIONS: Depressed patients with comorbid BPD display endocrine and immune alterations similar to those observed in cases of melancholic MDD without BPD. Elevated concentrations of serum cortisol, cortisol/DHEA ratios, and pro-inflammatory cytokines might indicate a state marker in these patients and might contribute to long-term metabolic alterations that have also been associated with MDD.

Visceral fat deposition and insulin sensitivity in depressed women with and without comorbid borderline personality disorder.

OBJECTIVE: Major depressive disorder (MDD) is associated with increased intra-abdominal fat, an important antecedent of noninsulin-dependent diabetes mellitus (NIDDM) and cardiovascular disorders. Furthermore, MDD is commonly accompanied by endocrine and immune dysregulation that has also been discussed in connection with the pathogenesis of NIDDM and ischemic heart disease. In borderline personality disorder (BPD), a dysregulation of the hypothalamic-pituitary-adrenal system has also been described. Therefore, our study aimed at examining visceral fat, insulin resistance, and alterations of cortisol and cytokines in young depressed women with and without comorbid BPD. METHODS: Visceral fat was measured in 18 premenopausal women with MDD and in 18 women comorbid with MDD and BPD by means of magnetic resonance tomography at the level of the first lumbar vertebral body. Twelve BPD patients without MDD and 20 healthy women served as the comparison groups. Concentrations of fasting cortisol, tumor necrosis factor-alpha, and interleukin-6 were measured, and indicators of insulin resistance and beta-cell sensitivity were calculated according to the homeostasis assessment model. RESULTS: We found increased visceral fat in women comorbid with MDD and BPD, and to a lesser extent, in women with MDD but without BPD. Insulin sensitivity was reduced in comorbid patients. Serum interleukin-6 (IL-6) and tumor necrosis factor-alpha concentrations were significantly increased in both groups of depressed patients. Reduced insulin sensitivity correlated with the amount of visceral fat and with serum concentrations of IL-6. CONCLUSION: Young depressed women with and without comorbid BPD display increased visceral fat and may constitute a risk group for the development of NIDDM and the metabolic syndrome. Our data support the hypothesis that the immune and endocrine alterations associated with MDD and BPD may contribute to the pathophysiologic processes associated with NIDDM.

The Abbott Architect c8000: analytical performance and productivity characteristics of a new analyzer applied to general chemistry testing.

Applying basic potentiometric and photometric assays, we evaluated the fully automated random access chemistry analyzer Architect c8000, a new member of the Abbott Architect system family, with respect to both its analytical and operational performance and compared it to an established high-throughput chemistry platform, the Abbott Aeroset. Our results demonstrate that intra- and inter-assay imprecision, inaccuracy, lower limit of detection and linear range of the c8000 generally meet actual requirements of laboratory diagnosis; there were only rare exceptions, e.g. assays for plasma lipase or urine uric acid which apparently need to be improved by additional rinsing of reagent pipettors. Even with plasma exhibiting CK activities as high as 40.000 U/l, sample carryover by the c8000 could not be detected. Comparison of methods run on the c8000 and the Aeroset revealed correlation coefficients of 0.98-1.00; if identical chemistries were applied on both analyzers, slopes of regression lines approached unity. With typical laboratory workloads including 10-20% STAT samples and up to 10% samples with high analyte concentrations demanding dilutional reruns, steady-state throughput numbers of 700 to 800 tests per hour were obtained with the c8000. The system generally responded to STAT orders within 2 minutes yielding analytical STAT order completion times of 5 to 15 minutes depending on the type and number of assays requested per sample. Due to its extended test and sample processing capabilities and highly comfortable software, the c8000 may meet the varying needs of clinical laboratories rather well.

Decreased osteoprotegerin and increased bone turnover in young female patients with major depressive disorder and a lifetime history of anorexia nervosa.

Low bone mineral density (BMD) is a frequent, often persistent complication in patients with major depressive disorder (MDD) and anorexia nervosa (AN) that increases the risk of pathologic fractures. The pathogenetic process underlying osteopenia in MDD and AN is still unclear, although several factors, including a dysbalance of cytokines, are associated with loss of bone mass. Alterations in the serum levels of cytokines have been observed in patients with MDD, AN, and other psychiatric disorders. Therefore, we examined serum levels of cytokines, markers of bone turnover, and BMD in 13 patients with MDD and a lifetime history of AN. Bone turnover markers (osteocalcin and C-terminal degradation products of type I collagen) and tumor necrosis factor alpha (TNF-alpha) in patients were significantly increased compared with those of the control group. Osteoprotegerin (OPG) in patients was significantly decreased. Eight of 13 patients (62%) displayed osteopenia at the lumbar spine. TNF-alpha correlated significantly with C-terminal degradation products of type I collagen, an osteoclastic marker, but significantly negatively with OPG. Our data suggest that TNF-alpha and OPG may play a role in the pathogenetic process underlying osteopenia in these patients.

Bone mineral density, markers of bone turnover, and cytokines in young women with borderline personality disorder with and without comorbid major depressive disorder.

OBJECTIVE: The pathogenesis of bone loss in major depressive disorder is a matter of debate. Studies of bone loss in nonpsychiatric medical disorders have found an association between the activation of osteoclastic cells and an imbalance of pro- and antiinflammatory cytokines. Since major depressive disorder is also associated with alterations in serum cytokine concentrations, the authors hypothesized that bone loss in patients with major depressive disorder and comorbid borderline personality disorder may be associated with cytokines capable of activating osteoclastic cells. METHOD: Twenty-two patients with borderline personality disorder and comorbid current or lifetime major depressive disorder were compared with 16 patients with borderline personality disorder who did not have major depressive disorder and 20 healthy volunteers. Bone mineral density was assessed by means of dual-energy x-ray absorptiometry. Markers of bone turnover as well as endocrine and immune measures were determined. RESULTS: The bone mineral density of 10 patients with borderline disorder plus current major depressive episode was significantly lower than that of the healthy subjects and the patients with borderline personality disorder without depression. Values of crosslaps, osteocalcin, serum cortisol, tumor necrosis factor-alpha (TNF-alpha), and interleukin-6 were significantly higher in the patients with borderline disorder plus current major depressive episode than in the healthy subjects. Crosslaps correlated positively with TNF-alpha but negatively with bone mineral density at the lumbar spine. Patients with borderline personality disorder who did not have current or lifetime depression displayed no alterations of either bone mineral density or the immunological and hormonal measures examined. CONCLUSIONS: Young women with comorbid borderline personality disorder and major depressive disorder have an elevated risk for osteoporosis. Borderline personality disorder per se is not associated with low bone mineral density. These data suggest that the immune and endocrine disturbances associated with depressive disorders in the context of borderline personality disorder may play a role in the pathophysiological process underlying bone loss in the patients studied.

Sensitive and specific photometric determination of mannitol in human serum.

Mannitol is an osmotically active polyalcohol often present in fluids used for irrigation of exposed tissue during minimal invasive surgery. Since this polyol normally is not detected in human plasma to any significant extent, it may be used as a laboratory marker of absorption of mannitol-containing irrigative fluids during surgery. For this aim, we developed a photometric assay of mannitol in human blood or serum that may be performed in a near-patient setting. Following deproteinization of the sample with trichloroacetic acid, the supernatant is mixed with NAD+ and a commercially available preparation of mannitol 2-dehydrogenase and is incubated at pH 7.8 and at 37 degrees C for 30 to 60 minutes. At the end of the incubation period the solution is appropriately diluted and the concentration of NADH formed by oxidation of mannitol is determined photometrically at 340 nm. The limit of detection of serum mannitol with this assay is 0.05 mmol/l, the linear range of measurement extends to about 3 mmol/l. At analyte concentrations of 0.48, 1.38 and 3.48 mmol/l, coefficients of inter-assay variation of 12.1, 6.7 and 4.9%, respectively, were obtained. The analytical recovery of mannitol added to serum samples was close to 100%. Of 27 polyalcohols, monosaccharides and oligosaccharides tested, none exhibited a measurable substrate activity and only D-fructose significantly inhibited the oxidation of mannitol at sample concentrations above 10 mmol/l; the enzymatic reaction, however, was strongly affected by EDTA. The suitability of the assay as a routine diagnostic tool for detection and quantification of intraoperatively absorbed irrigation fluid was demonstrated by analyzing mannitol in serum samples obtained from 24 patients undergoing transurethral prostatectomy.

Hemostasis and coagulation at a hematocrit level of 0.85: functional consequences of erythrocytosis.

We have generated a transgenic mouse line that reaches a hematocrit concentration of 0.85 due to constitutive overexpression of human erythropoietin in an oxygen-independent manner. Unexpectedly, this excessive erythrocytosis did not lead to thrombembolic complications in all investigated organs at any age. Thus, we investigated the mechanisms preventing thrombembolism in this mouse model. Blood analysis revealed an age-dependent elevation of reticulocyte numbers and a marked thrombocytopenia that matched the reduced megakaryocyte numbers in the bone marrow. However, platelet counts were not different from wild-type controls, when calculations were based on the distribution (eg, plasma) volume, thereby explaining why thrombopoietin levels did not increase in transgenic mice. Nevertheless, bleeding time was significantly increased in transgenic animals. A longitudinal investigation using computerized thromboelastography revealed that thrombus formation was reduced with increasing age from 1 to 8 months in transgenic animals. We observed that increasing erythrocyte concentrations inhibited profoundly and reversibly thrombus formation and prolonged the time of clot development, most likely due to mechanical interference of red blood cells with clot-forming platelets. Transgenic animals showed increased nitric oxide levels in the blood that could inhibit vasoconstriction and platelet activation. Finally, we observed that plasmatic coagulation activity in transgenic animals was significantly decreased. Taken together, our findings suggest that prevention of thrombembolic disease in these erythrocytotic transgenic mice was due to functional consequences inherent to increased erythrocyte concentrations and a reduction of plasmatic coagulation activity, the cause of which remains to be elucidated.

Early elevation of S-100B protein in blood after cardiac surgery is not a predictor of ischemic cerebral injury.

BACKGROUND: We hypothesized that early changes in S-100B levels after cardiac surgery are nonspecific and mostly reflect damage to tissues outside the brain rather than ischemic brain damage. METHODS: We measured serum levels of S-100B at several times perioperatively in 21 patients undergoing cardiac surgery. In addition, we measured levels of neuron specific enolase (NSE), glial fibrillary acidic protein (GFAP), creatine kinase (CK), the cardiac isoenzyme of CK (CK-MB), and myoglobin (MB) in these patients. RESULTS: Early increases in serum S-100B concentration were significantly (p<0.01) correlated with increases in markers of tissue injury outside the brain: S-100B/CK: r(2)=0.69; S-100B/CK-MB: r(2)=0.64; S-100B/myoglobin: r(2)=0.60; S-100B/NSE: r(2)=0.51; CK/NSE: r(2)=0.60; CK-MB/NSE: r(2)=0.59; and myoglobin/NSE: r(2)=0.54. CONCLUSIONS: Our findings indicate that increases in S-100B in the early phase after cardiac surgery are not due to release of S-100B from brain alone but also from tissue outside the brain.