Search

Background Venlafaxine is a dual serotonin (5-HT) and norepinephrine reuptake inhibitor. The specific dose at which it begins to efficiently engage the norepinephrine transporter (NET) remained to be determined. Paroxetine is generally considered as a selective 5-HT reuptake inhibitor but exhibits some affinity for NET. Atomoxetine is a NET inhibitor but also has some affinity for the 5-HT reuptake transporter (SERT). Methods This study examined the effects of forced titration of venlafaxine from 75 to 300 mg/d, paroxetine from 20 to 50 mg/d, or atomoxetine from 25 to 80 mg/d in 32 patients with major depressive disorder. Inhibition of SERT was estimated using the depletion of whole-blood 5-HT. Inhibition of NET was assessed using the attenuation of the systolic blood pressure produced by i.v. injections of tyramine. Results All 3 medications significantly reduced 5-HT levels at the initiating regimens: venlafaxine and paroxetine by approximately 60% and atomoxetine by 16%. The 3 subsequent regimens of venlafaxine and paroxetine reduced 5-HT levels by over 90%, but the highest dose of atomoxetine only reached a 40% inhibition. Atomoxetine dose dependently inhibited the tyramine pressor response from the lowest dose, venlafaxine from 225 mg/d, and paroxetine left it unaltered throughout. Conclusion These results confirm that venlafaxine and paroxetine are potent SERT inhibitors over their usual therapeutic range but that venlafaxine starts inhibiting NET only at 225 mg/d, whereas paroxetine remains selective for SERT up to 50 mg/d. Atomoxetine dose dependently inhibits NET from a low dose but does not inhibit SERT to a clinically relevant degree.

BACKGROUND: Individuals who have tested positive for cocaine have claimed that lidocaine, or its primary metabolite, norlidocaine (monoethylglycinexylidide (MEGX)), have caused false positive results for the cocaine metabolite benzoylecgonine (BE) on urinary immunoassay testing. OBJECTIVE: The goal of the study was to determine if lidocaine exposure from routine medical procedures can result in false positives on a commercially available cocaine immunoassay urine drug screen (UDS). METHODS: We performed a cross-sectional observational study of patients receiving lidocaine as part of their regular care. Standard immunoassay drug screens and confirmatory liquid chromatography-mass spectrometry (LC-MS) were performed on all urine samples to assess for MEGX and BE. RESULTS: In total, 168 subjects were enrolled; 121 samples positive for lidocaine were ultimately included for analysis. One hundred fourteen of the 121 were also positive for MEGX. None of the 121 were positive for cocaine/BE on the UDS (95% CI), 0–3.7% for the full sample and 0–3.9% for the 114 who tested positive for MEGX. CONCLUSION: The present study found no evidence that lidocaine or norlidocaine are capable of producing false positive results on standard cocaine urine immunoassays.

Given high health costs of depression during pregnancy and the first postnatal year, it is important to understand mechanisms involved in the emergence and perpetuation of symptoms during this time. In a series of 2 studies, we aim to clarify bidirectional relations between mothers' physiological stress regulation-stress-related activation of the hypothalamic-pituitary-adrenal (HPA) axis-and their course of depressive symptoms. In Study 1, 230 pregnant women recruited from a women's mental health program gave 3 saliva samples in the context of psychosocial stress at 24, 30, and 36-weeks gestation. They self-reported depressive symptoms across the three trimesters of pregnancy and first year postpartum. Multilevel models revealed women with elevated salivary cortisol during pregnancy showed a course of escalating ante- and postnatal symptoms, implicating HPA hyperactivation as a precursor to worsening mood problems. In Study 2, 54 mothers from a community sample self-reported depressive symptoms at 3, 6, 12, and 18 months postnatal. At 18 months, they participated in a dyadic stress task with their infant and gave 4 saliva samples for cortisol assay. For mothers with a lifetime depression diagnosis, an escalating course of postnatal symptoms predicted a higher, flatter cortisol response profile. Together, the results of these studies suggest that for high-risk mothers, a trajectory of worsening depression may both follow from and give rise to neuroendocrine stress hyperactivation. These findings suggest greater attention is warranted to course of depressive symptoms across the ante- and postnatal period, rather than symptom levels at any given time, to characterize health risks. (PsycINFO Database Record

The Predictors of Remission in Depression to Individual and Combined Treatments [PReDICT] study aimed to identify clinical and biological factors predictive of treatment outcomes in major depressive disorder among treatment-naive adults. The authors evaluated the efficacy of cognitive-behavioral therapy (CBT) and two antidepressant medications (escitalopram and duloxetine) in patients with major depression and examined the moderating effect of patients' treatment preferences on outcomes.Adults aged 18-65 with treatment-naive major depression were randomly assigned with equal likelihood to 12 weeks of treatment with escitalopram (10-20 mg/day), duloxetine (30-60 mg/day), or CBT (16 50-minute sessions). Prior to randomization, patients indicated whether they preferred medication or CBT or had no preference. The primary outcome was change in the 17-item Hamilton Depression Rating Scale (HAM-D), administered by raters blinded to treatment.A total of 344 patients were randomly assigned, with a mean baseline HAM-D score of 19.8 (SD=3.8). The mean estimated overall decreases in HAM-D score did not significantly differ between treatments (CBT: 10.2, escitalopram: 11.1, duloxetine: 11.2). Last observation carried forward remission rates did not significantly differ between treatments (CBT: 41.9%, escitalopram: 46.7%, duloxetine: 54.7%). Patients matched to their preferred treatment were more likely to complete the trial but not more likely to achieve remission.Treatment guidelines that recommend either an evidence-based psychotherapy or antidepressant medication for nonpsychotic major depression can be extended to treatment-naive patients. Treatment preferences among patients without prior treatment exposure do not significantly moderate symptomatic outcomes.

Busulfan therapeutic drug monitoring (TDM) is often used to achieve target plasma exposures. Variability in busulfan plasma exposure units (BPEU) is a potential source for misinterpretation of publications and protocols and is a barrier to data capture by hematopoietic cell transplantation (HCT) registry databases. We sought to harmonize to a single BPEU for international use. Using Delphi consensus methodology, iterative surveys were sent to an increasing number of relevant clinical stakeholders. In survey 1, 14 stakeholders were asked to identify ideal properties of a BPEU. In survey 2, 52 stakeholders were asked (1) to evaluate BPEU candidates according to ideal BPEU properties established by survey 1 and local position statements for TDM and (2) to identify potential facilitators and barriers to adoption of the harmonized BPEU. The most frequently used BPEU identified, in descending order, were area under the curve (AUC) in μM × min, AUC in mg × h/L, concentration at steady state (Css) in ng/mL, AUC in μM × h, and AUC in μg × h/L. All respondents conceptually agreed on the ideal properties of a BPEU and to adopt a harmonized BPEU. Respondents were equally divided between selecting AUC in μM × min versus mg × h/L for harmonization. AUC in mg × h/L was finally selected as the harmonized BPEU, because it satisfied most of the survey-determined ideal properties for the harmonized BPEU and is read easily understood in the clinical practice environment. Furthermore, 10 major professional societies have endorsed AUC in mg × h/L as the harmonized unit for reporting to HCT registry databases and for use in future protocols and publications.

Glucocorticoid challenge tests such as the dexamethasone suppression test (DST) and the combined dexamethasone/corticotropin-releasing hormone (dex-CRH) test are considered to be able to sensitively measure hypothalamic-pituitary-adrenal (HPA) axis activity in stress-related psychiatric and endocrine disorders. We used mass-spectrometry to assess the relationship of plasma dexamethasone concentrations and the outcome of these tests in two independent cohorts. Dexamethasone concentrations were measured after oral ingestion of 1.5mg dexamethasone in two cohorts that underwent a standard (dexamethasone at 23:00h) as well as modified (18:00h) DST and dex-CRH test. The first study population was a case/control cohort of 105 depressed patients and 133 controls in which peripheral blood mRNA expression was also measured. The second was a cohort of 261 depressed patients that underwent a standard dex-CRH test at baseline and after 12 weeks' treatment with cognitive-behavioral therapy or antidepressants. Dexamethasone concentrations explained significant proportions of the variance in the DST in both the first (24.6%) and the second (5.2%) cohort. Dexamethasone concentrations explained a higher proportion of the variance in the dex-CRH test readouts, with 41.9% of the cortisol area under the curve (AUC) in the first sample and 24.7% in the second sample. In contrast to these strong effects at later time points, dexamethasone concentrations did not impact cortisol or ACTH concentrations or mRNA expression 3hours after ingestion. In the second sample, dexamethasone concentrations at baseline and week 12 were highly correlated, independent of treatment type and response status. Importantly, a case/control effect in the Dex-CRH test was only apparent when controlling for dexamethasone concentrations. Our results suggest that the incorporation of plasma dexamethasone concentration or measures of earlier endocrine read-outs may help to improve the assessment of endocrine dysfunction in depression.

Background: Using high-frequency blood sampling, we demonstrate glucocorticoid fast feedback (FF) mediated by endogenous cortisol in 6 normal humans. Methods: We stimulated adrenocorticotropic hormone (ACTH) secretion by ovine corticotropin-releasing hormone (oCRH) with the experimental paradigm in which a high-frequency blood sampling was designed for plasma ACTH and cortisol determinations. Results: We saw previously unrecognized variability in the timing of key events such as onsets of ACTH and cortisol secretion, onset and offset of FF, and in FF duration. This variability mandated analyses referenced to case-wise event times rather than referenced simply to time since oCRH administration. The mean time of FF onset was 4.0 min (range 0–9; median 3) after cortisol secretion began, and the mean FF duration was 7.5 min (range 3–18; median 6.0). The FF effect was rate-sensitive and does not reflect level-sensitive cortisol feedback. In agreement with previous estimates using hydrocortisone infusions, the rate of rise of cortisol that triggered FF was approximately 44 nmol/L/min or 1.6 µg/dL/min. FF onset followed the trigger cortisol slope with an average lag of 1 min (range 0–3; median 0). Unexpectedly, this trigger cortisol slope quickly declined within the FF period. Conclusions: This experimental design may enable new physiological studies of human FF that is mediated by endogenous cortisol, including mechanisms, reproducibility, and generalizability to other activating stimuli.

To present a single-center 20-year experience with operated thyrotropinomas, including prevalence, clinical, biochemical and histological characteristics, and postoperative outcomes. Retrospective series of histopathologically-proven thyrotropinomas (1993–2013), divided in two groups: A (active, central hyperthyroidism) and B (silent, no hyperthyroidism). Of 1628 operated pituitary adenomas, 20 were β-TSH-positive (1.2 %). In increments of 5 years, proportion of thyrotropinomas was 1, 1, 0.04 and 1.77 % respectively. Median follow-up was 10.4 months (1.2–150). Group A: 6 patients (5 men), age 41 ± 12 years presented with hyperthyroidism (3), pituitary incidentaloma (2) and acromegaly (1). Tumor diameter was 2.1 ± 1.2 cm, FT4 2.68 ± 2.73 ng/dL; TSH 6.50 ± 3.68 µIU/mL. Glycoprotein alpha subunit (GSU) was uniformly elevated. Two patients had biochemical evidence of acromegaly. Tumors were plurihormonal (5 GH-positive); none atypical. Postoperative euthyroidism was achieved in 4 of 6 patients (66 %). Group B: 14 patients (7 men), age 47 ± 14 years presented with acromegaly (6), mass effect (4), incidentaloma (3) and galactorrhea (1). Tumor diameter was 2.0 ± 1.0 cm. Free T4 (1.00 ± 0.24 ng/dL) and TSH (2.02 ± 1.65 mIU/L) were lower than in group A (p

Sprague-Dawley rats selectively-bred for susceptibility to stress in our laboratory (Susceptible, or SUS rats) voluntarily consume large amounts of alcohol, and amounts that have, as shown here, pharmacological effects, which normal rats will not do. In this paper, we explore neural events in the brain that underlie this propensity to readily consume alcohol. Activity of locus coeruleus neurons (LC), the major noradrenergic cell body concentration in the brain, influences firing of ventral tegmentum dopaminergic cell bodies of the mesocorticolimbic system (VTA-DA neurons), which mediate rewarding aspects of alcohol. We tested the hypothesis that in SUS rats, alcohol potently suppresses LC activity to markedly diminish LC-mediated inhibition of VTA-DA neurons, which permits alcohol to greatly increase VTA-DA activity and rewarding aspects of alcohol. Electrophysiological single-unit recording of LC and VTA-DA activity showed that in SUS rats, alcohol decreased LC burst firing much more than in normal rats and as a result markedly increased VTA-DA activity in SUS rats while having no such effect in normal rats. Consistent with this, in a behavioral test for reward using conditioned place preference (CPP), SUS rats showed alcohol, given by intraperitoneal (i.p.) injection, to be rewarding. Next, manipulation of LC activity by microinfusion of drugs into the LC region of SUS rats showed that (a) decreasing LC activity increased alcohol intake and increasing LC activity decreased alcohol intake in accord with the formulation described above, and (b) increasing LC activity blocked both the rewarding effect of alcohol in the CPP test and the usual alcohol-induced increase in VTA-DA single-unit activity seen in SUS rats. An important ancillary finding in the CPP test was that an increase in LC activity was rewarding by itself, while a decrease in LC activity was aversive; consequently, effects of LC manipulations on alcohol-related reward in the CPP test were perhaps even larger than evident in the test. Finally, when increased LC activity was associated with (i.e., conditioned to) i.p. alcohol, subsequent alcohol consumption by SUS rats was markedly reduced, indicating that SUS rats consume large amounts of alcohol because of rewarding physiological consequences requiring increased VTA-DA activity. The findings reported here are consistent with the view that the influence of alcohol on LC activity leading to changes in VTA-DA activity strongly affects alcohol-mediated reward, and may well be the basis of the proclivity of SUS rats to avidly consume alcohol.

Background An inverse association between Parkinson disease (PD) and total vitamin D levels has been reported but it is unknown whether vitamin D from different sources, i.e. 25(OH)D2 (from diet and supplements) and 25(OH)D3 (mainly from sunlight exposure), all contribute to the association.

BACKGROUND Busulfan is an anti-leukemic, DNA alkylating agent that is used in conditioning regimens for patients undergoing hematopoietic stem cell transplantation. Because of the large intraindividual and interindividual variations seen in busulfan pharmacokinetics, therapeutic drug monitoring is necessary. Currently at the authors' institution, plasma busulfan in adults is measured by gas chromatography-mass spectrometry (GC-MS) at a reference laboratory, whereas pediatric specimens are sent to a different reference laboratory also for GC-MS analysis. As the result turnaround time is not optimal and this practice is of significant cost, a liquid chromatography-tandem mass spectrometry assay to quantify plasma busulfan was developed. METHODS Protein precipitation with D8-busulfan (deuterated internal standard) in acetonitrile was carried out on 50 µL of heparinized plasma. Gradient elution with ammonium acetate, formic acid, water, and methanol at 0.6 mL/min had a 4-minute run time. Multiple reaction monitoring was employed using Q1/Q3 transitions of 264/151 and 264/55 for busulfan and 272/159 and 272/62 for D8-busulfan. RESULTS Sample preparation took ∼30 minutes for 6 patient samples. Six calibrators were used (0-2000 ng/mL) with 3 quality controls (means of 12, 356, and 1535 ng/mL). The limits of detection and quantitation were 1 and 6 ng/mL, respectively. Extraction recovery was ∼77% and ion suppression ∼5%. Within-run and between-run precision studies yielded

The aims of this study were to characterize the alterations in total and free carbamazepine (CBZ) and in total and free carbamazepine-epoxide (CBZ-EPO) clearances during pregnancy, to calculate the change in free fractions of CBZ and CBZ-EPO during pregnancy, and to determine whether seizure worsening is associated with a low ratio to nonpregnant baseline concentration of total or free CBZ or CBZ-EPO. Women on CBZ were enrolled before conception or during pregnancy in this prospective, observational study. Concomitant medications and seizure frequency were recorded. Serum total and free CBZ and CBZ-EPO were collected at each visit. Changes in the clearance of all four compounds and free fractions of CBZ and CBZ-EPO were compared with nonpregnant baseline. During pregnancy, the ratios to baseline concentrations of total and free CBZ and CBZ-EPO were compared for months with and without increased seizure frequency. Total and free CBZ and CBZ-EPO clearances were calculated in 15 pregnancies in 12 women. Clearances did not change for any of these compounds during pregnancy. The free fraction of CBZ increased from 0.23 at baseline to a maximum of 0.32 in the third trimester (p=0.008). In the six women on CBZ monotherapy with adequate seizure diaries and blood sampling, seizure worsening did not correspond to a ratio to baseline concentration of less than 0.65 for total or free CBZ or CBZ-EPO. In conclusion, total and free CBZ and CBZ-EPO clearances did not change substantially during pregnancy, and seizure frequency worsening was not associated with decreased concentrations of total or free CBZ; therefore, therapeutic drug monitoring may not be necessary for all women on CBZ during pregnancy. Further studies with larger sample sizes are needed before definitive recommendations can be made. Carbamazepine monotherapy may be a relatively safe and cost effective treatment option for women with focal epilepsy syndromes during pregnancy.

Adoption of targeted mass spectrometry (MS) approaches such as multiple reaction monitoring (MRM) to study biological and biomedical questions is well underway in the proteomics community. Successful application depends on the ability to generate reliable assays that uniquely and confidently identify target peptides in a sample. Unfortunately, there is a wide range of criteria being applied to say that an assay has been successfully developed. There is no consensus on what criteria are acceptable and little understanding of the impact of variable criteria on the quality of the results generated. Publications describing targeted MS assays for peptides frequently do not contain sufficient information for readers to establish confidence that the tests work as intended or to be able to apply the tests described in their own labs. Guidance must be developed so that targeted MS assays with established performance can be made widely distributed and applied by many labs worldwide. To begin to address the problems and their solutions, a workshop was held at the National Institutes of Health with representatives from the multiple communities developing and employing targeted MS assays. Participants discussed the analytical goals of their experiments and the experimental evidence needed to establish that the assays they develop work as intended and are achieving the required levels of performance. Using this “fit-for-purpose” approach, the group defined three tiers of assays distinguished by their performance and extent of analytical characterization. Computational and statistical tools useful for the analysis of targeted MS results were described. Participants also detailed the information that authors need to provide in their manuscripts to enable reviewers and readers to clearly understand what procedures were performed and to evaluate the reliability of the peptide or protein quantification measurements reported. This paper presents a summary of the meeting and recommendations.

Objective The objective of the study was to characterize changes in the oral clearance (CL/F) of lamotrigine (LTG) over the course of pregnancy and the postpartum period through a model-based approach incorporating clinical characteristics that may influence CL/F, in support of developing clinical management guidelines. Methods Women receiving LTG therapy who were pregnant or planning pregnancy were enrolled. Maternal blood samples were collected at each visit. A pharmacokinetic analysis was performed using a population-based, nonlinear, mixed-effects model. Results A total of 600 LTG concentrations from 60 women (64 pregnancies) were included. The baseline LTG CL/F was 2.16 L/h with a between-subject variability of 40.6%. The influence of pregnancy on CL/F was described by gestational week. Two subpopulations of women emerged based on the rate of increase in LTG CL/F during pregnancy. The gestational age-associated increase in CL/F displayed a 10-fold higher rate in 77% of the women (0.118 L/h per week) compared to 23% (0.0115 L/h per week). The between-subject variability in these slopes was 43.0%. The increased CL/F at delivery declined to baseline values with a half-life of 0.55 weeks. Interpretation The majority of women had a substantial increase in CL/F from 2.16 to 6.88 L/h by the end of pregnancy, whereas 23% of women had a minimal increase. An increase in CL/F may correspond to decreases in LTG blood concentrations necessitating the need for more frequent dosage adjustments and closer monitoring in some pregnant women with epilepsy. Postpartum doses should be tapered to preconception dose ranges within 3 weeks of delivery.

Context.—It is recommended that hemoglobin (Hb) A1c (Hb A1c) not be used to assess average glycemia in patients who have altered red blood cell life span. Objective.—To investigate the frequency of reporting an Hb A1c value for Hb variant samples that do not include Hb A. Design.—Hb A1c samples (n = 500) were procured and screened for Hb variants that may affect Hb A1c interpretation (Hb SS, Hb SC, and Hb S–β-thalassemia). Five of each of these samples were tested by ion-exchange high-performance liquid chromatography, immunoturbidimetric assay, second-generation immunoturbidimetric assay, and affinity chromatography. Results.—Eleven (2.2%) homozygous Hb SS, 6 (1.2%) Hb SC, and 5 (1.0%) Hb S–β-thalassemia samples were identified out of the 500 samples tested. Three of 4 instruments investigated in this study are known to not be plagued by analytic interference from these Hb variants but disturbingly reported Hb A1c values in the absence of Hb A. Conclusions.—The improved analytic specificity of Hb A1c platforms has by and large eliminated interferences from the most common heterozygous Hb variants. A consequence, however, is the potential for unintended reporting of Hb A1c results in the presence of homozygous and compound heterozygous Hb variants that lack Hb A and the inability to distinguish those samples not recommended to be used for patient care. The ability to identify samples harboring Hb variants that preclude the utility of Hb A1c may be beneficial in high prevalence populations.

Children of women treated with antiepileptic drugs (AEDs) are at increased risk for adverse outcomes detectable in the neonatal period, which may be associated with the amount of AED in the fetal circulation. Placental passage of AEDs can be measured by calculating the ratio of umbilical cord to maternal AED concentrations collected at delivery. The aims of this study were to determine the umbilical cord concentrations and umbilical to maternal ratios for AEDs, and to determine whether higher cord concentrations are associated with increased risk of neonatal complications. AED cord and maternal blood concentrations from 70 mother-newborn dyads and neonatal complications were recorded. Logistic regressions were performed to determine the association between AED concentrations and complications. Mean umbilical to maternal ratios for total concentrations ranged from 0.79 for carbamazepine to 1.20 for valproic acid, and mean umbilical to maternal ratios for free concentrations ranged from 0.86 for valproic acid to 1.42 for carbamazepine, indicating complete placental passage. Neither umbilical cord concentrations nor umbilical to maternal ratios were associated with adverse neonatal outcomes. Additional investigations are warranted to delineate the relationship between quantified fetal AED exposure and neonatal complications.

To the Editor: Current clinical practice guidelines in the transplant setting necessitate the complete cessation of smoking to be considered a candidate for listing on the United Network for Organ Sharing (UNOS).1 The negative health consequences of smoking are well documented, as are the adverse outcomes in donors and recipients of solid organs who smoke, particularly in cases involving the lungs (1). Transplantation programs therefore rely heavily upon the laboratory to carry out the analysis and interpretation of tobacco screening assays to ensure abstinence in patients as part of the evaluation for listing in UNOS. Nicotine and its primary metabolite cotinine are the two most commonly monitored compounds to determine smoking status in patients. Nicotine is rapidly metabolized in vivo to cotinine, which has a much longer half-life (20 h vs 2 h), and therefore substantially extends the detection window (2). Ambiguity can arise however if a patient is using nicotine replacement therapy (NRT; nicotine-containing gums or patches as well as the vapor pens). These products contain nicotine and therefore produce positive nicotine and cotinine results, which can potentially prohibit patients from receiving a life-saving organ. To address this issue several reference laboratories have developed mass spectrometry–based assays for detection …

Context Acromegaly has been associated with calcium-phosphate and bone turnover alterations. Controlled studies of these interactions are sparse. Objective To evaluate calcium and bone metabolism in active and treated acromegaly. Design/Setting/Patients We conducted a controlled, prospective study at a tertiary referral center. We studied 22 patients with acromegaly referred for surgical or medical therapy (ACM) and 22 with nonfunctioning pituitary adenomas referred for surgery (control). Main Outcome Measures Calcium (serum and urine), phosphorus, parathyroid hormone (PTH), 25-hydroxy- and 1,25-dihydroxy-vitamin D, bone turnover markers [serum C-terminal telopeptide of type 1 collagen (CTX) and procollagen type 1 N-terminal propeptide (P1NP)], and cytokines [receptor activator of nuclear factor κB ligand (RANK-L) and osteoprotegerin (OPG)] at baseline and 3 to 6 months after treatment. Results At baseline, the ACM group had lower PTH levels than controls (36.3 ± 13.9 pg/mL vs 56.0 ± 19.9 pg/mL) and higher phosphorus (4.34 ± 0.71 mg/dL vs 3.55 ± 0.50 mg/dL) (P < 0.01). Groups had similar levels of serum and urine calcium and 25-hydroxy- and 1,25-dihydroxy-vitamin D. The ACM group had higher bone turnover markers than control; P1NP and CTX were strongly correlated (r2 = 0.82, P < 0.05). CTX was dependent on age and disease group but not on sex or gonadal status. After treatment of acromegaly, serum calcium (9.52 ± 0.43 mg/dL to 9.26 ± 0.28 mg/dL), phosphorus (4.34 ± 0.71 mg/dL to 3.90 ± 0.80 mg/dL), and CTX (0.91 ± 0.75 ng/mL to 0.63 ± 0.68 ng/mL) decreased, while PTH increased (36.3 ± 13.9 pg/mL to 48.9 ± 16.7 pg/mL) (P < 0.01). 25-hydroxy-vitamin D, P1NP, and RANK-L/OPG ratio did not change significantly. Conclusion Acromegaly patients exhibited PTH-independent calcium-phosphate alterations and enhanced coupled bone formation and resorption. Within 6 months of treatment, bone resorption decreased, whereas RANK-L/OPG changes were inconsistent.

Recidivism, repeated criminal behavior after conviction and correction of prior offenses, is a costly problem across the nation. However, the contribution of empathy in determining the risk of recidivism has received limited attention, although lack of empathy has been related to antisocial personality disorder in various studies. Studies linked testosterone to aggression, antisocial behavior, and criminality, and evidence support hormonal connections between empathy and aggression. Adult male prison inmates convicted of violent or nonviolent offenses were included in a cross-sectional study of empathy, antisocial behavior, salivary testosterone, and recidivism. Subjects underwent criminal history, Empathy Quotient, Levenson Self-Report Psychopathy Scale, Beck Depression Inventory, Spielberger State-Trait Anxiety Inventory, and salivary testosterone assays. Bivariate analyses indicated multiple correlations between variables. Multivariate modeling analyses found a significant relationship between self-reported conviction number and psychopathy scale score (p = 0.013). These preliminary results suggest avenues of investigation of factors contributing to recidivism risk.

It was in 1965 that Drs. Ron Malzack and Patrick Wall published the “gate control theory” of pain in Science (1). This theory of chronic pain speculated that neural gates in the spinal cord could be made to open or close by signals …

Context.—Laboratory medicine is an integral component of patient care. Approximately 60% to 70% of medical decisions are based on laboratory results. Physicians in specialties that order the tests are teaching medical students laboratory medicine and test use with minimal input from laboratory scientists who implement and maintain the quality control for those tests.Objective.—To develop, implement, and evaluate a 1.5-day medical student clinical laboratory experience for fourth-year medical students in their last month of training.Design.—The experience was devised and directed by laboratory scientists and included a panel discussion, laboratory tours, case studies that focused on the goals and objectives recently published by the Academy of Clinical Laboratory Physicians and Scientists, and medical-student presentations highlighting salient points of the experience. The same knowledge quiz was administered at the beginning and end of the experience and 84 students took both quizzes.Results.—A score of 7 or more was obtained by 16 students (19%) on the initial quiz, whereas 34 (40%) obtained the same score on the final quiz; the improvement was found to be statistically significant (P = .002; t = 3.215), particularly in 3 out of the 10 questions administered.Conclusions.—Although the assessment can only measure a small amount of knowledge recently acquired, the improvement observed by fourth-year medical students devoting a short period to learning laboratory medicine principles was encouraging. This medical student clinical laboratory experience format allowed teaching of a select group of laboratory medicine principles in 1.5 days to an entire medical school class.

Neurofilament light (NFL) proteins in cerebrospinal fluid (CSF) are a marker of neuronal damage, especially subcortical axonal injury and white matter disease. Subjects with Alzheimer’s disease (AD) have shown elevated levels of CSF NFL as compared to controls. However, the presence of the APOE ε4 allele, an established risk factor for AD, was not found to associate with higher CSF NFL concentrations. We examined whether TOMM40 variants, which have been reported to influence age of onset of AD and are in linkage disequilibrium with APOE, have an effect on CSF NFL levels, in 47 healthy, cognitively intact individuals with or without APOE ε4. Our results show that the presence of APOE ε4 alone does not affect CSF NFL levels significantly; however APOE and TOMM40 appear to interact. Subjects with APOE ε4 have higher CSF NFL levels than non- ε4 carriers, only when they do not carry a short poly-T variant of TOMM40, which is associated with later age of onset of AD, and may act as protective against the dose effect of ε4.

Gliomas are a group of aggressive brain tumors that diffusely infiltrate adjacent brain tissues, rendering them largely incurable, even with multiple treatment modalities and agents. Mostly asymptomatic at early stages, they present in several subtypes with astrocytic or oligodendrocytic features and invariably progress to malignant forms. Gliomas are difficult to classify precisely because of interobserver variability during histopathologic grading. Identifying biological signatures of each glioma subtype through protein biomarker profiling of tumor or tumor-proximal fluids is therefore of high priority. Such profiling not only may provide clues regarding tumor classification but may identify clinical biomarkers and pathologic targets for the development of personalized treatments. In the past decade, differential proteomic profiling techniques have utilized tumor, cerebrospinal fluid, and plasma from glioma patients to identify the first candidate diagnostic, prognostic, predictive, and therapeutic response markers, highlighting the potential for glioma biomarker discovery. The number of markers identified, however, has been limited, their reproducibility between studies is unclear, and none have been validated for clinical use. Recent technological advancements in methodologies for high-throughput profiling, which provide easy access, rapid screening, low sample consumption, and accurate protein identification, are anticipated to accelerate brain tumor biomarker discovery. Reliable tools for biomarker verification forecast translation of the biomarkers into clinical diagnostics in the foreseeable future. Herein we update the reader on the recent trends and directions in glioma proteomics, including key findings and established and emerging technologies for analysis, together with challenges we are still facing in identifying and verifying potential glioma biomarkers.

Rigorous data regarding fetal central nervous system (CNS) exposure after antidepressant exposure are sparse. The magnitude of serotonin reuptake inhibitor (SRI) CNS exposure was measured in three groups of rats using ex vivo autoradiography of the serotonin transporter (SERT): 1) in utero, 2) postnatal clearance after birth, and 3) exposure through lactation. Rats were exposed to one of five SRI-type antidepressants (escitalopram, fluoxetine, paroxetine, sertraline, and venlafaxine) administered continuously via osmotic minipumps to pregnant or nursing dams. Dam dosing was adjusted to reflect the 50th and 85th percentiles of serum concentrations observed in pregnant women. Embryonic day 21 rat pups exposed in utero exhibited >80% SERT occupancy in brain tissue, which is equivalent to that of the pregnant dam and similar to that reported for human pharmacotherapy. Venlafaxine was the exception with occupancies ranging from 61 to 92% across different litters. The magnitude of SERT occupancy is essentially equivalent between dams and fetuses. By postnatal day 4, high SERT occupancy was observed only in fluoxetine-exposed pups (41–92% occupancy). Significantly less, but measurable, exposure occurred via breast milk exposure even in the absence of detectable drug concentrations in nursing pup sera. Pups exposed to SRIs via breast milk for 3 or 7 days exhibited varying SERT occupancies (0–57% depending on the individual medication and dam dose). These data highlight the need for animal modeling of fetal and nursing infant drug exposure using clinically meaningful dosing strategies and appropriate CNS measures to develop rational treatment guidelines that systematically minimize fetal and neonatal medication exposure in humans.

Summary Objective Clinical and preclinical studies indicate that maternal stress during pregnancy may exert long-lasting adverse effects on offspring. This investigation sought to identify factors mediating the relationship between maternal and neonatal hypothalamic–pituitary–adrenal (HPA) axes in pregnant women with past or family psychiatric history. Patients Two hundred and five pairs of maternal and umbilical cord blood samples from a clinical population were collected at delivery. Measurements Maternal and neonatal HPA axis activity measures were plasma adrenocorticotrophic hormone (ACTH), total cortisol, free cortisol and cortisol-binding globulin concentrations. The effects of maternal race, age, body mass index, psychiatric diagnosis (DSM-IV), birth weight, delivery method and estimated gestational age (EGA) at delivery on both maternal and neonatal HPA axis measures were also examined. Incorporating these independent predictors as covariates where necessary, we evaluated whether neonatal HPA axis activity measures could be predicted by the same maternal measure using linear regression. Results Delivery method was associated with umbilical cord plasma ACTH and both total and free cord cortisol concentrations (T = 10·53–4·21; P

BACKGROUND Clinical proteomics presents great promise in biology and medicine because of its potential for improving our understanding of diseases at the molecular level and for detecting disease-related biomarkers for diagnosis, prognosis, and prediction of therapeutic responses. To realize its full potential to improve clinical outcome for patients, proteomic studies have to be well designed, from biosample cohorts to data and statistical analyses. One key component in the biomarker development pipeline is the understanding of the regulatory science that evaluates diagnostic assay performance through rigorous analytical and clinical review criteria. CONTENT The National Cancer Institute's Clinical Proteomic Technologies for Cancer (CPTC) initiative has proposed an intermediate preclinical “verification” step to close the gap between protein-based biomarker discovery and clinical qualification. In collaboration with the US Food and Drug Administration (FDA), the CPTC network investigators recently published 2 mock submission review documents, first-of-their-kind educational materials that may help the scientific community interested in developing products for the clinic in understanding the likely analytical evaluation requirements for multiplex protein technology–based diagnostic tests. CONCLUSIONS Building on this momentum, the CPTC continues with this report its collaboration with the FDA, as well as its interactions with the AACC and the Centers for Medicare and Medicaid Services, to further the understanding of regulatory requirements for approving multiplex proteomic platform–based tests and analytically validating multiple analytes.

Busulfan is used in myeloablative preparation regimens for hematopoietic bone marrow transplantation. Due to its narrow therapeutic range therapeutic drug monitoring of busulfan is recommended. In this study a fast and simple method for measuring busulfan in serum or plasma by liquid chromatography–tandem mass spectrometry (LC–MS/MS) has been developed utilizing turbulent flow online extraction technology. Serum or plasma was mixed with acetonitrile containing d8-busulfan. After centrifugation the supernatant was injected onto a turbulent flow preparatory column then transferred to a C18 analytical column monitored by a tandem mass spectrometer set at positive electrospray ionization. The analytical cycle time was 4.0 min. The method was linear from 0.15 to 41.90 μmol/L with an accuracy of 87.9–103.0%. Inter- and intra-assay CVs across four concentration levels were 2.1–7.8%. No significant carryover or ion suppression was observed. No interference was observed from commercial control materials containing more than 100 compounds. Comparison with a well established LC–MS/MS method using patient specimens (n = 45) showed a mean bias 1.3% with Deming regression of slope 1.02, intercept −0.02 μmol/L, and a linear correlation coefficient 0.9883. The LC–MS/MS method coupled with turbulent flow online sample cleaning technology described here offers reliable busulfan quantitation in serum or plasma with minimum manual sample preparation and was fully validated for clinical use.

The concern that antidepressant (AD) drugs, especially selective serotonin reuptake inhibitors and paroxetine (PAR) in particular, can increase suicidality during the early treatment of juvenile patients (children and adolescents) has created a dilemma for clinicians treating depressives. Although preclinical research cannot resolve controversy in this area, our present findings may provide insight into how AD drugs might, under certain conditions, exacerbate rather than ameliorate the depressive state. Both clinical and preclinical evidences indicate that the principal noradrenergic cell group in the brain, the locus coeruleus (LC), is overactive in depressives and that, conversely, effective AD treatments decrease the activity of LC neurons. We report here that short-term (2 and 4 days) administration of PAR produces an increase in the activity of LC neurons (spontaneous firing rate and sensory-evoked responses) in young rats, contrary to the ‘therapeutic' decrease in activity typically observed in adult rats. Blood levels of PAR were lower in young rats than in adult rats, although similar low blood levels produced by a lower dose of PAR in adult rats failed to produce an increase in LC activity. In addition, activity of young rats in the swim test was determined to assess depressive-like responses. The same dose/durations of PAR, which produced the largest increases in LC activity in young rats, produced decreases in swim-test activity, indicating that brief administration of PAR in young rats can promote, rather than reduce, the depressive state. These results offer a model that may help screen potential adjunctive treatments to avoid early adverse effects of ADs.

Objective: To examine the extent to which a common genetic pathway is also involved in the relationship between depressive symptoms, in the absence of major depressive disorder (MDD), and inflammation. Recent data suggested that MDD and inflammation share common genes. Methods: We recruited 188 male twins from the Vietnam Era Twin Registry who were free of symptomatic coronary artery disease and MDD, with mean +/- standard deviation (SD) age of 55 +/- 2.75 years, including 54 monozygotic and 40 dizygotic twin pairs. These pairs were assessed for two inflammatory markers, interleukin (IL)-6 and C-reactive protein (CRP). Current depressive symptoms were measured with the Beck Depression Inventory-II. Generalized estimating equations were used to examine the phenotypic association between depression and inflammatory markers. Biometrical genetic modeling was performed to estimate the genetic and environmental contributions to this association. Results: An association was observed between severity of current depressive symptoms and increased levels of inflammatory markers (p

Objectives: The aims of this study were to determine the relative influence of genetic and environmental contributions to inflammatory biomarkers, and to what extent correlations among these markers are due to genetic or environmental factors.Methods: We performed univariate and multivariate genetic analyses of four inflammatory markers: interleukin-6 (IL-6), soluble 1L-6 receptor (sIL-6R), C-reactive protein (CRP), and fibrinogen, in 166 (88 monozygotic and 78 dizygotic) middle-aged male twin pairs.Results: The mean age (+/- S.D.) of the twins was 54 (+/- 2.93) years. Heritability was substantial for CRP (0.61, 95% CI: 0.47-0.72) and moderate to fair for IL-6 (0.31, 0.13-0.46), sIL-6R (0.49, 0.30-0.76) and fibrinogen (0.52, 0.34-0.65). IL-6, CRP and fibrinogen showed significant correlations, but not with sIL-6R. Multivariate genetic analysis found that these correlations could be best explained by a common pathway model, where the common factor explained 27%, 73% and 25% of the variance of IL-6, CRP and fibrinogen, respectively. About 46% (95% CI: 21-64%) of the correlations among the three inflammatory markers could be explained by the genetic factors. After adjusting for covariates known to influence inflammation levels, heritability estimates were slightly decreased but the overall results remained similar.Conclusions: A significant part of the variation in inflammatory marker levels is due to genetic influences. Furthermore, almost 50% of the shared variance among these biomarkers is due to a common genetic factor which likely plays a key role in the regulation of inflammation. (c) 2008 Elsevier Ireland Ltd. All rights reserved.

OBJECTIVE. Although lamotrigine use during pregnancy has substantially increased over the past decade secondary to accumulated reproductive safety data, systematic data on lamotrigine during breastfeeding remains sparse. We sought to characterize the determinants of lamotrigine concentrations in breast milk and nursing-infant plasma. PATIENTS AND METHODS. Women who enrolled in a prospective investigation of perinatal medication pharmacokinetics, were treated with lamotrigine, and chose to continue lamotrigine while breastfeeding were included in the analysis. Breast milk samples were collected via breast pump from foremilk to hindmilk from a single breast to determine the excretion gradient and serial samples over 24 hours to determine the time course of excretion. Paired maternal/infant plasma samples were also collected. Lamotrigine concentrations in all of the samples were determined by using high-performance liquid chromatography with ultraviolet detection. Statistical analyses of breast milk and infant plasma concentrations and their determinants were conducted. RESULTS. Thirty women and their nursing infants participated in the study, providing a total of 210 breast milk samples. The mean milk/plasma ratio was 41.3%. There was a nonsignificant trend for higher lamotrigine concentrations in breast milk 4 hours after the maternal dose. Infant plasma concentrations were 18.3% of maternal plasma concentrations. The theoretical infant lamotrigine dose was 0.51 mg/kg per day, and the relative infant lamotrigine dose was 9.2%. Mild thrombocytosis was present in 7 of 8 infants at the time of serum sampling. No other adverse events were observed or reported in the breastfed infants. CONCLUSIONS. Consistent with previous investigations of medications in breast milk, the lamotrigine milk/plasma ratio is highly variable. The rate of lamotrigine excretion into human breast milk is similar to that observed with other antiepileptic drugs. These data expand the extant literature on lamotrigine in breastfeeding and demonstrate relatively comparable nursing-infant exposure to lamotrigine compared with other antiepileptic drugs.

This chapter describes a method to measure the oral anticoagulants dabigatran, rivaroxaban, apixaban, and warfarin in plasma samples using ultra-performance liquid chromatography combined with tandem mass spectrometry (UPLC-MS/MS). The instrument is operated in multiple reaction monitoring (MRM) mode with an electrospray ionization (ESI) source in positive ionization mode. Samples are extracted with a 90:10 methanol/0.1 N hydrochloric acid solution containing stable isotope-labeled internal standards for each analyte. After centrifugation the supernatant is transferred to a mass spectrometry vial, injected onto the UPLC-ESI-MS/MS, and quantified using an eight-point calibration curve.

To characterize the magnitude and course of alterations in total and free lamotrigine (LTG) clearance (Cl) during pregnancy and the postpartum period, to assess the impact of therapeutic drug monitoring (TDM) on seizure frequency, to determine the ratio to individual target LTG concentration that is associated with increased seizure risk, and to evaluate maternal postpartum toxicity.A cohort of women were enrolled before conception or during pregnancy in this prospective, observational study. Visits occurred every 1 to 3 months with review of seizure and medication diaries, examination, and blood sampling. Total and free LTG Cls were calculated. Individualized target concentrations were used for TDM. The ratio to target concentration (RTC) was compared between patients with and without increased seizures. A receiver operating characteristic curve determined the threshold RTC that best predicts increased seizure frequency.Analysis of 305 samples in 53 pregnancies demonstrated increased total and free LTG Cl in all trimesters above nonpregnant baseline (p0.001), with peak increases of 94% and 89% in the third trimester. Free LTG Cl was higher in white compared with black women (p0.05). Increased seizure frequency (n = 36 women with epilepsy) in the second trimester was associated with a lower RTC (p0.001), and RTC0.65 was a significant predictor of seizure worsening. An empiric postpartum taper reduced the likelihood of maternal LTG toxicity (p0.05) (n = 27). Newborn outcomes were similar to the general population (n = 52).These novel data contribute to a rational treatment plan and dosing paradigm for lamotrigine use during pregnancy, parturition, and the postpartum period.

Current practice guidelines discourage use of lithium during breast-feeding, despite limited data. This study aimed to quantify lithium exposure in nursing infants.In 10 mother-infant pairs, the authors obtained assays of lithium in maternal serum, breast milk, and infant serum and indices of infant renal and thyroid function.Maternal serum, breast milk, and infant serum daily trough concentrations of lithium averaged 0.76, 0.35, and 0.16 meq/liter, respectively, each lithium level lower than the preceding level by approximately one-half. No serious adverse events were observed, and elevations of thyroid-stimulating hormone, blood urea nitrogen, and creatinine were few, minor, and transient.Serum lithium levels in nursing infants were low and well tolerated. No significant adverse clinical or behavioral effects in the infants were noted. These findings encourage reassessment of recommendations against lithium during breast-feeding and underscore the importance of close clinical monitoring of nursing infants.

This chapter describes a method to measure the oral anticoagulants dabigatran, rivaroxaban, apixaban, and warfarin in plasma samples using ultra-performance liquid chromatography combined with tandem mass spectrometry (UPLC-MS/MS). The instrument is operated in multiple reaction monitoring (MRM) mode with an electrospray ionization (ESI) source in positive ionization mode. Samples are extracted with a 90:10 methanol/0.1 N hydrochloric acid solution containing stable isotope-labeled internal standards for each analyte. After centrifugation the supernatant is transferred to a mass spectrometry vial, injected onto the UPLC-ESI-MS/MS, and quantified using an eight-point calibration curve.

Various symptoms of mental illness occur commonly during pregnancy. It is estimated that serious mental disorders, including major depression, bipolar disorder, schizophrenia, panic and other anxiety disorders, occur with a frequency of 10 to 25% in community samples of US women in their child-bearing years. As a result, approximately a third of all women take at least one psychoactive drug during pregnancy. Fetal drug exposure has been documented for all psychoactive drugs studied to date. However, the rate and extent of placental transfer within and between psychoactive drug classes remains ill defined. The contribution of various genetic factors such as the role of polymorphic drug metabolizing enzymes and drug transporters in controlling the variability of fetal drug exposure is also unclear. Therapeutic drug monitoring (TDM) has traditionally played an important role in psychiatric pharmacotherapy during pregnancy to ensure an adequate drug dose to achieve desired benefits while avoiding excessive fetal accumulation for drugs. In the genomic era, individualized treatment with specific drugs tailored to the mother's and fetus's genotype should eventually become the standard of care. Several methodological problems need to be overcome for this prediction to become reality. One approach to this goal taken by the Specialized Center of Research on Sex and Gender Factors Affecting Women's Health at the Emory University Women's Mental Health Program is described. This research is grounded on TDM of pregnant women receiving antidepressants, antipsychotics, anti-epileptic drugs and mood stabilizers. The use of pharmacokinetic and pharmacogenetic models to predict maternal plasma drug concentrations, fetal drug exposure, and maternal and neonatal outcomes, is expected to improve our understanding of dose-response relationships of psychoactive drugs in pregnancy.

Background: Analysis of proteins has been an integral part of the field of clinical chemistry for decades. Recent advances in technology and complete identification of the human genome sequence have opened up new opportunities for analysis of proteins for clinical diagnostic purposes. Methods: Content of a recent conference of proteomics is summarized. Results: New analytical methods allow the simultaneous analysis of a large number of proteins in biological fluids such as serum and plasma, offering partial views of the complete set of proteins or proteome. Plasma presents many analytical challenges, such as the complexity of components, predominance of a few major components, and the large concentration range of components, but the number of proteins that can be detected in plasma has expanded dramatically from hundreds to thousands. At the same time, there is increased capability to detect structural variations of proteins. Recent studies also identified the presence of complex sets of small protein fragments in plasma. This set of protein fragments, the fragmentome or peptidome, is potentially a rich source of information about physiologic and disease processes. Conclusions: Advances in proteomics offer great promise for the discovery of markers that might serve as the basis for new clinical laboratory tests. There are many challenges, however, in the translation of newly discovered markers into clinical laboratory tests.

Objective: Basal levels of glucocorticoids, such as cortisol, are generally unaltered in bipolar disorder. However, neuroendocrine tests of glucocorticoid receptor (GR) function such as the dexamethasone suppression test (DST) are frequently abnormal. Neuropsychological impairment is well documented in healthy volunteers after administration of glucocorticoids and in patients with bipolar affective disorder. This suggests a potential link between neuropsychological and hypothalamic-pituitary-adrenal axis function. We examined the hypothesis that neuropsychological impairment in bipolar disorder is associated with abnormal GR function. Methods: Seventeen euthymic bipolar patients and 16 controls completed tests of verbal declarative and working memory (WM) tests and the DST. The correlation between neuroendocrine and neuropsychological function was examined. Results: Bipolar patients made significantly more errors of omission and commission on the WM paradigm and demonstrated impaired verbal recognition memory. Patients’ post-dexamethasone cortisol correlated with WM commission errors (rs = 0.64, p = 0.0006). No such relationship was evident in controls. Conclusion: Deficits in declarative memory and WM are evident in patients with bipolar disorder. The deficit in retrieval accuracy from WM appears to be correlated with abnormal GR function.

Background The use of antidepressants during pregnancy continues to garner considerable attention, though there are limited investigations that have sought to quantify fetal exposure. Methods Maternal and umbilical cord sera were collected at delivery from ten women taking nortriptyline and seven taking clomipramine. Placental passage was calculated as the ratio of umbilical cord to maternal serum concentration. Obstetrical outcome data were gathered from subjects at delivery. Results The placental passage ratio of nortriptyline and its active metabolite, cis-10-hydroxynortriptyline, were .68 ± .40, 1.40 ± 2.40, respectively. Clomipramine and desmethylclomipramine ratios were .60 ± .50, .80 ± .60. Obstetrical complications, such as pre-term delivery and pregnancy induced hypertension, were increased compared to the national average. Conclusions The in vivo ratios of umbilical cord to maternal serum drug concentrations demonstrate considerable fetal exposure and differ greatly from previous results utilizing ex vivo perfusion.

Objective: Lithium has been used during pregnancy for more than four decades, but quantification of fetal lithium exposure and clinical correlations of such exposure are limited. The study objectives were to 1) quantify the rate of lithium placental passage, 2) assess any association between plasma concentration of lithium at delivery and adverse perinatal events, and 3) determine whether lithium concentrations can be reduced by briefly suspending therapy proximate to delivery. Method: Maternal blood and umbilical cord blood were obtained at delivery for assay of lithium concentrations, and obstetrical outcome data were collected prospectively for 10 participants. These data were combined with results from MEDLINE and PsycINFO searches that identified 32 cases in which maternal lithium was administered throughout delivery. Statistical analysis of the pooled data was conducted. Results: The ratio of lithium concentrations in umbilical cord blood to maternal blood (mean=1.05, SD=0.13) was uniform across a wide range of maternal concentrations (0.2–2.6 meq/liter). Significantly lower Apgar scores, longer hospital stays, and higher rates of CNS and neuromuscular complications were observed in infants with higher lithium concentrations (>0.64 meq/liter) at delivery. Withholding lithium therapy for 24–48 hours before delivery resulted in a 0.28 meq/liter reduction in maternal lithium concentration. Conclusions: Lithium completely equilibrates across the placenta. Higher lithium concentrations at delivery are associated with more perinatal complications, and lithium concentrations can be reduced by brief suspension of therapy proximate to delivery. Treatment guidelines are proposed to improve neonatal well-being when lithium use is indicated in late pregnancy.

To the Editor: Falsely increased plasma troponin (Tn) I and T results have been reported for several Tn methods, including the Beckman Coulter UniCel DxI AccuTnI assay (Beckman Coulter, Chaska, MN) (1–3). We and others have also observed falsely increased human chorionic gonadotropin (hCG) using the Beckman Coulter Access Total βhCG on the UniCel DxI (1). These false increases were identified by the finding of substantially lower results following high-speed recentrifugation and reanalysis, suggesting a particulate interference. However, the sources of these false increases were not previously determined. In reviewing clinical data for patients from whom plasma samples were found to generate falsely high hCG results on the UniCel DxI in our laboratories, we found these patients had high blood leukocyte counts. Based on this finding, we investigated the interference of leukocytes in the Beckman Coulter Access Total βhCG assay. This study was approved by the Emory Institutional Review Board. First, we measured hCG in leftover plasma samples from patients with known high blood leukocyte content of >25 × 103/μL. The thirteen randomly selected samples (10 male, 3 female) were inverted several times in the original lithium heparin plasma separator tubes (PSTs) (Becton Dickinson) to disturb any particulates settled during storage (up to 24 h refrigerated) and then measured …

Benzodiazepines (BZPs) have been shown to reduce hypothalamic-pituitary-adrenal (HPA) axis activity acutely in normal humans. In contrast, the effects of chronic BZP treatment on the HPA axis have not been well studied, especially in the geriatric population. This study examined the acute and chronic effects (3 weeks) of alprazolam and lorazepam on plasma cortisol in 68 subjects (60-83 years) who received 0.25 or 0.50 mg b.i.d. alprazolam, or 0.50 or 1.0 mg b.i.d. lorazepam, or placebo orally according to a randomized, double-blind, placebo-controlled parallel design. Memory assessment and blood samples for plasma cortisol were obtained prior to the morning dose on days 0, 7, 14, and 21, and at 1, 2.5, and 5 h postdrug on days 0 and 21. Assessments of anxiety and depression were carried out at days 0, 7, 14, and 21 before drug administration. Plasma cortisol was affected compared to placebo only by the 0.5 mg alprazolam dose. During the first and the last day of treatment, there was a significant drop in cortisol at 2.5 h after alprazolam compared to placebo. The predose cortisol levels increased significantly during chronic alprazolam treatment, and correlations were found between these cortisol changes and changes in depression, anxiety, and memory scores. These findings suggest that even a short period of chronic treatment with alprazolam, but not lorazepam, may result in interdose HPA axis activation in the elderly, consistent with drug withdrawal. If confirmed, this effect may contribute to an increased risk for drug escalation and dependence during chronic alprazolam treatment.

Background: The purpose of this study was to attain a new landmark in the area of selective serotonin reuptake inhibitor therapy during lactation by establishing a basis for interpreting infant serum concentrations and for minimizing infant exposure in the absence of treatment-emergent side effects. Method: Breast milk and paired maternal and infant sera were collected following maternal treatment with sertraline monotherapy (25-200 mg/ day) administered once daily. Sertraline and its major metabolite were measured in breast milk and serum samples using high-performance liquid chromatography with UV detection (limit of detection = 2 ng/mL). Results: Twenty-six nursing women with DSM-IV major depressive disorder participated in the study; the mean (SD) daily sertraline dose was 123.9 (62.8) mg/day. Fifteen women submitted 182 breast milk samples for analysis of gradient (foremilk to hindmilk) and time course of medication excretion. The milk/plasma ratio was highly variable (range, 0.42-4.81). A significant gradient and time course of excretion for both sertraline (p

Using purified enzyme preparations, we investigated the actions of angiotensin-converting enzyme, aminopeptidase N, and endopeptidase 24.11 on corticotropin-releasing factor (CRF). The effects of inhibition of these enzymes on CRF action in rat anterior pituitary cultures were also determined. Finally, specific inhibitors were used to evaluate ectopeptidase action on the regional brain metabolism of CRF. K(m) values for CRF were 165, 90, and 42 microM for angiotensin-converting enzyme, aminopeptidase N, and endopeptidase 24.11, respectively. A CRF metabolite profile for each enzyme was determined. In pituitary cultures, inhibition of endopeptidase 24.11 and aminopeptidase N potentiated CRF-stimulated release of adrenocorticotropic hormone (ACTH). In rat pituitary and hypothalamus membrane preparations, specific inhibitor experiments indicated that CRF hydrolysis involved members of the neutral endopeptidase and aminopeptidase enzyme families. In cortex membranes, similar peptidase inhibition was without effect. These data support the hypothesis that ectopeptidases play a major role in CRF metabolism and biological function.