HER2 expression and markers of phosphoinositide-3-kinase pathway activation define a favorable subgroup of metastatic pulmonary adenocarcinomas.

OBJECTIVES: Pulmonary adenocarcinomas (ADC) can be sub-grouped based on dominant oncogenic drivers. EGFR mutations define an entity of metastatic ADC with favorable prognosis and high susceptibility to EGFR tyrosine kinase inhibition. In contrast, the clinical impact of additional ERBB family members in ADC is less defined. To this end we prospectively studied HER2 expression, gene amplification, and mutation in relation to outcome of patients with advanced or metastatic ADC. MATERIALS AND METHODS: Diagnostic tumor biopsies from 193 sequential patients with stage III/IV ADC were prospectively studied for HER2 expression by immunohistochemistry (IHC). Cases with IHC scores 2+ or 3+ were analyzed by HER2 chromogenic in situ hybridization (CISH), and sequencing of HER2 exons 20 and 23. Additional prospectively determined biomarkers included PTEN, cMET, pAKT, and pERK expression, KRAS, EGFR, BRAF and PIK3CA mutations, and ALK fluorescence ISH (FISH). RESULTS AND CONCLUSION: HER2-IHC was feasible in 176 (91.2%) cases. Of 53 (30%) cases with IHC scores 2+/3+, 45 (85%) could be studied by CISH and 34 (64%) by sequencing. The lower number of HER2-mutational analyses resulted from exhaustion of tumor tissue and DNA following mutational analysis of KRAS, EGFR, BRAF and PIK3CA. HER2 amplification was detected in 4 cases (2.3%), while no mutation was found. HER2 expression correlated with expression of pAKT and cMET. Expression of HER2 and pAKT was associated with favorable overall survival in stage IV disease. HER2-expressing ADC more frequently harbored KRAS mutations, while HER2 expression was absent in all 4 cases with BRAF mutation. HER2-IHC was not predictive of HER2 gene amplification or mutation, which both were rare events in prospectively studied patients with advanced or metastatic ADC. Expression of HER2 and pAKT define a population of patients with stage IV ADC with a distinct disease course, who could benefit from specifically tailored pharmacotherapies.

Valproic acid downregulates NF-κB p50 activity and IRAK-1 in a progressive thyroid carcinoma cell line.

Histone deacetylase inhibitor (HDACI) valproic acid (VPA) is a promising drug, currently in clinical phase 2, for the therapy of advanced/poorly differentiated thyroid cancer. The nuclear factor-κB (NF-κB) pathway is constitutively activated in most tumors, including thyroid carcinomas; this often contributes to aggressive tumor growth and therapeutic resistance. We hypothesized that VPA could be useful to decrease NF-κB activity in human thyroid cancer cells. To clarify this, we treated the highly progressive thyroid cancer cell line BHT-101 with VPA (1.0-3.0 mM) for 48 h. Real-time polymerase chain reaction (PCR) and Western blot were used to measure expression of NF-κB-regulatory genes and proteins. NF-κB p50 activity was measured using an ELISA-based colorimetric transcription factor assay kit. We found that VPA significantly and dose-dependently impaired NF-κB activity reducing DNA binding activity of NF-κB p50 subunit by 30% at 1 mM, 40% at 1.5 mM, and 70% at 3 mM. Expression of interleukin-1 receptor-associated kinase-1 (IRAK-1) protein, an upstream mediator of NF-κB activation, was reduced by Ì´30% at 1 and 1.5 mM. Furthermore, 3 mM VPA treatment significantly decreased expressions of IRAK-1, phospho-IκBα and NF-κB p50 subunit protein by Ì´ 50%. This is the first study to demonstrate that VPA decreases NF-κB activity in a progressive thyroid cancer cell line. Intriguingly, 1mM of VPA, a clinically safe dose in the therapeutic range for epilepsy, was sufficient to reduce NF-κB activity. Thus, VPA may be a promising agent to overcome chemoresistance in cancer therapy and to improve therapeutic efficiency.

[Diagnosis of pulmonary tuberculosis using Ziehl-Neelsen stain and polymerase chain reaction]. / Diagnostik der Lungentuberkulose mit Ziehl-Neelsen-Färbung und Polymerasekettenreaktion.

BACKGROUND: Definitive diagnosis of unclear pulmonary lesions is mainly based on morphological methods. In addition to a neoplasm, inflammatory reactions, in particular tuberculosis (TB), have to be considered in most cases. Therefore, the aim of this work was to determine whether established methods used in general pathology can be efficiently used with cytological material. MATERIALS AND METHODS: An established polymerase chain reaction (PCR) protocol for the detection of Mycobacterium tuberculosis complex (Mtc) DNA in fixed specimens was conducted on fixed material available as an assay for liquid-based cytology (LBC). CytoLyt®-fixed material of 45 patients with clinically suspected TB or other mycobacteriosis were selected and were initially tested cytologically. In cases of absent tumor cells, PCR for detection of Mtc DNA and Ziehl-Neelsen stain (ZN) were performed. RESULTS: In 9 patients (20 %), Mtc DNA was found by PCR. The following methods were used to obtain material: catheter biopsy (5), needle biopsy (2), transbronchial needle aspiration (1), and bronchoalveolar lavage (1). Cytologically an inflammatory reaction was observed in all cases. In 2 patients, a history of TB, in 2 further cases either silicosis or a posttransplant situation was known. In cases with a positive PCR, 7 patients (78 %) were positive in ZN and 3 patients (33.3 %) in TB culture (15.5 % vs. 6.7 % of the total cohort); however, the material used for investigation was not always from identical sources, respectively. In 36 out of 45 patients, both PCR and ZN were negative for the detection of Mtc DNA. CONCLUSION: The material intended for LBC can be used for detection of TB with ZN and Mtc PCR.

[Glandular papilloma of the right main bronchus. Detection of an exon 2 mutation of the KRAS gene (c.35G>A)]. / Glanduläres Papillom des rechten Hauptbronchus. Nachweis einer Exon-2-Mutation des KRAS-Gens (c.35G>A).

Benign epithelial tumors of the tracheobronchial system and the lungs are exceedingly rare. These entities encompass squamous and glandular papillomas (as well as their mixed forms) and adenomas (alveolar adenoma, papillary adenoma, salivary gland-like pleomorphic and mucinous adenomas and mucinous cystadenomas). These tumors are considered to be biologically benign neoplasms; however, they can pose considerable diagnostic difficulties, especially during frozen section evaluation, as they can mimic malignant tumors and in particular they can resemble well differentiated papillary adenocarcinomas. As a result of the extreme rarity of these tumors only a few descriptive diagnostic series exist and a systematic investigation including molecular data does not exist. This article presents the case of a 64-year-old patient with a glandular papilloma of the right main bronchus including the immunohistochemical and molecular work-up as well as a review of the current literature.

Oncogenic RAS simultaneously protects against anti-EGFR antibody-dependent cellular cytotoxicity and EGFR signaling blockade.

Monoclonal antibodies against the epidermal growth factor receptor (EGFR) are effective cancer therapeutics, but tumors harboring RAS mutations are resistant. To functionally dissect RAS-mediated resistance, we have studied clinically approved anti-EGFR antibodies, cetuximab and panitumumab, in cancer models. Both antibodies were equally cytotoxic in vitro. However, cetuximab, which also triggers antibody-dependent cellular cytotoxicity (ADCC), was more effective than panitumumab in vivo. Oncogenic RAS neutralized the activity of both antibodies in vivo. Mechanistically, RAS upregulated BCL-XL in cancer cell lines and in primary colorectal cancers. Suppression of BCL-XL by short hairpin RNA or treatment with a BH3 mimetic overcame RAS-mediated antibody resistance. In conclusion, RAS-mutant tumors escape anti-EGFR antibody-mediated receptor blockade as well as ADCC in vivo. Pharmacological targeting of RAS effectors can restore sensitivity to antibody therapy.

[MicroRNA profiles in fine needle biopsy of the thyroid]. / MicroRNA-Profile in der Feinnadelbiopsie der Schilddrüse.

MicroRNAs (miRNAs) are small (20-24 nucleotides), non-coding ribonucleid acids, which regulate gene expression on the post-transcriptional level, thus influencing physiological processes including cellular growth, differentiation and apoptosis. Several miRNAs (e. g. miRNAs 146b, 221 and 222) have been shown to be consistently over-expressed in papillary thyroid carcinoma. The present overview describes and discusses the utilization and problems of miRNA analysis in material from thyroid nodules obtained by fine needle biopsy. Particularly the analysis of defined sets of miRNAs should improve the diagnostic value of this procedure and contribute to a better management of patients with cold thyroid nodules.

Differential expression of microRNA-675, microRNA-139-3p and microRNA-335 in benign and malignant adrenocortical tumours.

BACKGROUND: For the clinical management of adrenocortical neoplasms it is crucial to correctly distinguish between benign and malignant tumours. Even histomorphologically based scoring systems do not allow precise separation in single lesions, thus novel parameters are desired which offer a more accurate differentiation. The tremendous potential of microRNAs (miRNAs) as diagnostic biomarkers in surgical pathology has recently been shown in a broad variety of tumours. METHODS: In order to elucidate the diagnostic impact of miRNA expression in adrenocortical neoplasms, a cohort of 20 adrenocortical specimens including normal adrenal tissue (n=4), adrenocortical adenomas (ACAs) (n=9), adrenocortical carcinomas (ACCs) (n=4) and metastases (n=3) was analysed using TaqMan low density arrays to identify specific miRNA profiles in order to distinguish between benign and malignant adrenocortical lesions. Results were validated in a validation cohort (n=16). RESULTS: Concerning the differential diagnosis of ACAs and ACCs, 159 out of 667 miRNAs were up- and 89 were down-regulated in ACAs. Using real-time PCR analysis of three of the most significantly expressed single key miRNAs allowed separation of ACAs from ACCs. ACCs exhibited significantly lower levels of miR-139-3p (up to 8.49-fold, p<0.001), miR-675 (up to 23.25-fold, p<0.001) and miR-335 (up to 5.25-fold, p<0.001). A validation cohort of 16 specimen with known Weiss score showed up-regulation of miR-335 and miR-675 in the majority of cases with probable malignant course, although overlapping values exist. CONCLUSION: miRNA profiling of miR-675 and miR-335 helps in discriminating ACCs from ACAs. miRNA analysis may indicate malignant behaviour in cases with indeterminate malignant potential.

Differential miRNA expression profiles in variants of papillary thyroid carcinoma and encapsulated follicular thyroid tumours.

BACKGROUND: Recent studies showed a significant upregulation of distinct microRNAs (miRNAs) in papillary thyroid carcinoma (PTC). The objective of this study was to explore whether this upregulation could also be assigned to distinct histomorphological variants of PTC, especially the follicular variant and other encapsulated follicular thyroid tumours. METHODS: We used total RNA of 113 formalin-fixed paraffin-embedded tissues of 50 PTCs ((10 conventional type (PTC-CT), 10 tall cell variants (PTC-TCVs), 30 follicular variants (PTC-FVs)), 10 follicular adenomas (FAs), 10 multinodular goitres (MNGs), 21 follicular thyroid carcinomas and 22 well-differentiated tumours of unknown malignant potential (WDT-UMP) to analyse the miRNA expression pattern of five selected miRNAs (146b, 181b, 21, 221 and 222) using RT-PCR TaqMan miRNA assay to explore the diagnostic utility of this method. RESULTS: The mean values of the expression pattern of all miRNAS in PTCs show a statistically significant difference from those in MNG and FA with fold changes up to 90 for miRNA 146b, P<0.001. No differences in expression pattern could be showed between MNG and FA. The PTC-FVs differ significantly from FA in all five miRNAS, from MNG in three and from WDT-UMP in one miRNA with fold changes between 1.7 and 21.2, but failed to be of diagnostic value regarding individual cases with substantial overlaps. CONCLUSION: We conclude that analysis of a set of five selected miRNAS distinguish common variants of PTC from FA/MNG but failed to be a useful diagnostic method in individual and doubtful cases, especially in the differential diagnosis of encapsulated follicular thyroid tumours.

Lack of correlation between BRAF V600E mutational status and the expression profile of a distinct set of miRNAs in papillary thyroid carcinoma.

Recent studies demonstrated a significant upregulation of distinct microRNAs (miRNAs), small endogenous RNAs that regulate gene expression, in papillary thyroid carcinoma (PTC). In the pathogenesis of PTC the T1799A (V600E) BRAF mutation is the most common genetic alteration leading to a constitutive activation of the MAPK pathway. The aim of the present study was to elucidate a possible correlation between BRAF mutational status and a distinct miRNA expression profile. In a series of 221 PTC we determined the BRAF V600E mutational status using DNA-sequencing and correlated the occurrence of the mutation with a variety of clinicopathologcial data. The miRNA expression profile of five selected subtypes (miRNA-146b, -181b, -21, -221, -222) in two matched cohorts of BRAF positive (n=28) and wildtype cases (n=26) was examined by RT-PCR TaqMan miRNA assay. The BRAF V600E mutation was significantly found in PTCs with extrathyroidal extension (p <0.001). Among them, V600E was even significantly associated with smaller tumour size of 1 cm or less (microcarcinomas; p<0.003) and the follicular (p=0.017) and tall cell variant (p=0.015). By calculating relative changes in miRNA gene expression no differences in fold changes could be detected between BRAF positive and wildtype PTC suggesting that BRAF has no regulatory influence on the expression of the five examined miRNAs. However, our study confirmed the diagnostic utility of this distinct set of miRNAs to detect PTC by significant fold changes in at least 3 miRNAs (miRNA-146b, -221, -222) irrespective of its histological variant.

Analysis of deregulated miRNAs is helpful to distinguish poorly differentiated thyroid carcinoma from papillary thyroid carcinoma.

Poorly differentiated thyroid carcinoma (PDTC) is defined as a malignant follicular cell derived neoplasm, both morphologically and biologically intermediate between well differentiated and anaplastic thyroid carcinoma (ATC). In the present study we investigated the expression levels of two distinct sets of miRNAs ('set 1': miRNA-146b, -181b, -21, -221, -222, all shown to be significantly upregulated in papillary thyroid carcinoma [PTC]; 'set 2': miRNA-30d, -125b, -26a, -30a-5p, and let7c, all downregulated in ATC) in a series of 15 PDTC (including 3 mixed PDTC/PTC), 9 'pure' PTC, and 9 ATC. Compared to normal thyroid tissue all 'set 1' miRNAs were significantly upregulated in PTC (p<0.001); in ATC 4/5 miRNAs were upregulated (p<0.001) whereas in PDTC the expression levels of all 5 miRNAs did not differ significantly from normal thyroid. All miRNAs of 'set 2' were significantly upregulated in PTC (p<0.004) and downregulated in ATC (p<0.03); in PDTC only 3/5 were downregulated (p<0.011). All 10 miRNAs investigated differed significantly (p<0.003) between PTC and PDTC. In the histologically differentiated PTC compound of mixed PDTC/PTC cases, however, miRNA expression levels of all 10 miRNAs investigated lacked significant difference from those found in the PDTC compound, whereas 6/10 miRNAs differed significantly from 'pure' PTC. Our results indicate that analysis of distinct sets of miRNAs represent useful tools to distinguish PDTC from 'pure' PTC. Additionally our findings suggest that lack of deregulation of some miRNAs may select a subset of PTC prone to progression to PDTC.

Expression and mutation analysis of the tyrosine kinase c-kit in poorly differentiated and anaplastic thyroid carcinoma.

Poorly differentiated and anaplastic thyroid carcinoma are aggressive tumors failing to res-pond to conventional therapy. Imatinib mesylate offers an effective therapeutic option in patients with various types of malignancies by inhibiting tyrosine kinases such as c-kit. In this study we investigated c-kit expression in anaplastic and poorly differentiated thyroid carcinoma compared to differentiated carcinoma and adenoma and the presence of c-kit mutations. In total, 224 thyroid tissues were analyzed by immunohistochemistry. Mutation analysis of exon 9, 11, 13, and 17 of the c-kit gene was performed in anaplastic and poorly differentiated carcinoma. c-Kit expression was negative in all anaplastic thyroid carcinoma, while c-kit expression of poorly differentiated carcinoma showed a high variability with a more intense staining in tumors showing obvious differentiated malignant follicular tumor areas. Differentiated carcinoma showed a slight, but not significantly stronger c-kit expression than poorly differentiated carcinoma. All tumors revealed wild type sequences of c-kit gene in exons 9, 11, 13, and 17. The low or lacking c-kit expression in undifferentiated thyroid carcinoma together with the lack of mutations argue against a crucial role of c-kit in thyroid carcinoma cell proliferation. Further molecular targets of imatinib mesylate have to be analyzed to estimate a potential benefit of this drug for patients with dedifferentiated thyroid carcinoma.

Activation of extracellular regulated kinases (ERK1/2) but not AKT predicts poor prognosis in colorectal carcinoma and is associated with k-ras mutations.

Signal transduction and modulation represent central mechanisms in cellular processes such as cell-cycle regulation, oncogenesis, and apoptosis. The aim of this study was to determine the prognostic relevance of two kinases important in the regulation of cell proliferation and apoptosis in 135 colorectal cancer cases: AKT and extracellular regulated kinases (ERK1/2). We investigated the relationship of phospho-ERK1/2 (pERK1/2) and phospho-AKT (pAKT) with associated parameters (EGFR, COX-2, cyclin-D1), proliferative activity (Ki-67), and apoptosis (TUNEL) using immunohistochemistry. Additionally, the k-ras gene was screened for mutations to determine its putative association with ERK1/2 activation. Activation of ERK1/2 but not AKT correlated statistically with the presence of k-ras mutations (P = 0.015). Survival analysis of phospho-ERK1/2 immunoexpression showed a significant correlation with decreased overall survival (OS). The multivariate Cox regression analysis identified pERK1/2 as an independent prognostic parameter (P = 0.005). Activation of ERK1/2 in colorectal cancer may indicate aggressive tumor behavior and may constitute an independent prognostic factor. Furthermore, our data suggest that mutations of the k-ras oncogene may induce activation of ERK1/2. We propose immunohistochemical determination of pERK1/2 status as a promising candidate for the identification of high-risk patients who would benefit from new anticancer drugs targeting the ERK pathway.

ETV6-NTRK3 gene fusion in a secretory carcinoma of the breast of a male-to-female transsexual.

Secretory carcinomas of the breast were first described as "juvenile carcinoma" by McDivitt and Stewart in a cohort of children. This term has been replaced by the term "secretory breast carcinoma", because the entity can occur at any time of life. Carcinoma of the male breast is uncommon and accounts for approximately 1% of all cancers in men. Recently, it has been reported that human secretory breast carcinoma expresses the ETV6-NTRK3 gene fusion that was previously cloned in pediatric mesenchymal cancers. We present the case of a 46-year-old male-to-female transsexual in whom a secretory breast carcinoma was an incidental finding. As confirmation of the histopathological diagnosis we detected the novel ETV6-NTRK3 gene fusion in this tumor.

[Substances other than alcohol found in the blood among Danish road-users during a week in 1996]. / Andre stoffer end alkohol i blodet hos danske trafikanter. En undersøgelse af trafiksager fra en uge i 1996.

INTRODUCTION: This investigation is the Danish contribution to a Nordic comparative study of other drugs than alcohol found in road users. MATERIAL AND METHODS: 255 blood samples received from the police for alcohol and/or drug determination during one week in 1996 were investigated for drugs. RESULTS: 56 (22%) of the 255 blood samples were positive for other drugs than alcohol. Cannabis was detected in 11%, benzodiazepines, mainly diazepam and flunitrazepam, in 9% and amphetamine in 5% of the blood samples. DISCUSSION: The police suspected other drugs than alcohol in 3% of the 255 blood samples, but drugs were detected in 22%. This investigation showed that the frequency of other drugs than alcohol was similar in Denmark and Norway for the blood samples with an alcohol concentration above the statutory limit. This contrasts with the fact that the number of blood samples from road users investigated for substances other than alcohol is about 200/year in Denmark and 4000/year in Norway.

[Fatal intoxications among drug addicts in Denmark in 1997]. / Forgiftningsdødsfald blandt narkomaner i Danmark i 1997.

INTRODUCTION: The purpose of this study was to investigate fatal poisonings among drug addicts in 1997 and to compare the results to similar investigations from 1985 and 1991. MATERIAL AND METHODS: All fatal intoxications among drug addicts in Denmark in 1997, investigated at the three Institutes of Forensic Medicine in Denmark. RESULTS: The number of fatal intoxications increased by 32% from 1991 to 1997, mainly outside the metropolitan area, The average age increased from 32 to 36 years. The proportion of heroin/morphine intoxications increased from 57% to 71%. The most commonly used drugs were as in 1991 heroin/morphine, diazepam and methadone. The frequency of cocaine increased from one positive case in 1991 to 14% positive cases in 1997. DISCUSSION: This study showed an increasing number of fatal intoxications and changes in drug abuse pattern and place of death since 1991.

[Citalopram in forensic samples. Citalopram concentrations in samples from legal autopsies and from living persons in connection with traffic accidents or cases of violence in Denmark 1989-1996]. / Citalopram i retskemiske sager. Citalopramkoncentrationer i prøver fra retslige obduktioner og fra levende personer i forbindelse med trafik- eller voldssager i Danmark fra 1989 til 1996.

Citalopram was found in 92 autopsy cases and 27 cases from living persons and the concentrations are described. A range of 6.2-19 mumol/kg whole blood was found in cases where citalopram alone was the cause of death and a range of 1.9-16 mumol/kg whole blood in cases, where citalopram together with other compounds were considered to be the cause of death. In autopsy cases toxic concentrations were in the range 1.2-2.8 mumol/kg whole blood and concentrations between 0:09 and 1.9 mumol/kg were considered therapeutic. In cases from living persons the citalopram concentrations in whole blood were 0.06-0.9 mumol/kg.

Reverse transcriptase polymerase chain reaction as a reliable method to detect epidermal growth factor receptor exon 2-7 gene deletion in human glioblastomas.

Epidermal growth factor receptor (EGFR) gene amplification has been reported to occur in diverse carcinoma types such as lung, ovarian, and breast carcinomas and in glioblastomas. A 801-bp in-frame deletion close to the aminoterminus of the receptor protein has been found to occur more or less frequently within at least three of these tumor entities. We studied EGFR gene alterations using the polymerase chain reaction and EGFR gene expression of 65 astrocytic tumors (51 glioblastomas World Health Organization [WHO] IV, five anaplastic astrocytomas WHO III, and nine astrocytomas WHO II). EGFR gene amplification, as determined by Southern blotting using a full-length cDNA probe, was observed in 22 of 51 glioblastomas (43%) but in none of the grade II astrocytomas. Two of five anaplastic astrocytomas at WHO III showed a considerable degree of EGFR amplification but, according to the neuroradiological data, these two tumors had to be considered as glioblastomas. The most frequently found genetic alteration was the 801-bp deletion near the receptor aminoterminus comprising a complete loss of exon 2 to exon 7 (del2-7). We showed that RT-PCR is superior to Southern blot analysis in detection of this type of deletion and can be assigned to 9 of 38 (24%) glioblastomas examined. Expression of a EGF receptor protein was enhanced in most of the tumors with gene amplification. However, 5 of 18 tumors that express a receptor protein in the absence of EGFR gene amplification also showed elevated levels of EGFR gene expression. In addition to the full-length receptor protein, a signal in the 140-kDa range was observed in 17 of 35 glioblastomas (49%). This fragment may correspond to the truncated de12-7 receptor protein or might be due to proteolysis of the full-length receptor protein.

[Fatal poisonings during a 5-year period in Eastern Denmark]. / Forgiftningsdødsfald over en 5-årig periode i Ostdanmark.

In the period 1992-1996, both years included, 1079 cases of deaths from poisoning by drugs or poisons were found by forensic-chemical analyses at The Institute of Forensic Medicine, Dept. of Forensic Chemistry, in Copenhagen, covering a population of 2.4 million. Morphine was by far the most frequently occurring compound accounting for 421 deaths, followed by methadone with 185 deaths. Then alcohol, ketobemidone, and carbon monoxide were represented with 80, 74 and 66 deaths, respectively. Drug addicts dominated in the survey with 549 cases. According to Danish law, autopsy with following chemical analyses must be performed on all dead drug addicts, whereas many other deaths by poisoning are defined only from the medicine found in the vicinity of the dead body.

Citalopram concentrations in samples from autopsies and living persons.

Concentrations of citalopram in medicolegal samples from 92 autopsies and 27 living persons are described. In autopsy cases in which citalopram alone was the cause of death, concentrations ranged from 2.0 to 6.2 mg/kg whole blood. In autopsy cases in which citalopram together with other substances was considered to be the cause of death, the concentrations of citalopram ranged from 0.6 to 5.2 mg/kg whole blood. In autopsy cases toxic concentrations ranged from 0.4 to 0.9 mg/kg whole blood and therapeutic concentrations from 0.03 to 0.6 mg/kg whole blood. In samples from living persons the concentrations of citalopram in whole blood were 0.02 to 0.3 mg/kg.