Mastocytosis and related entities: a practical roadmap

Mastocytosis is a complex heterogenous multisystem disorder that is characterized by pathologic activation or accumulation of neoplastic mast cells (MCs) in one or more organs. This clonal MC expansion is often associated with a somatic gain-of-function mutation (D816V in most of the cases) in the KIT gene, encoding for the MC surface receptor KIT (CD117), a stem cell growth factor receptor. Based on clinical and biochemical criteria, the World Health Organization (WHO) divided mastocytosis into different subclasses. The exact prevalence of mastocytosis remains elusive, but it is estimated that the disease affects approximately 1 in 10,000 persons. The clinical presentation of mastocytosis varies significantly, ranging from asymptomatic patients to a life-threatening disease with multiple organ involvement, potentially leading to cytopenia, malabsorption, hepatosplenomegaly, lymphadenopathy, ascites or osteolytic bone lesions with pathological fractures. Patients with mastocytosis may experience symptoms related to release of MC mediators, such as flushing or diarrhea or even more severe symptoms such as anaphylaxis. Recently, a new genetic trait, hereditary alpha tryptasemia (HaT), was described which involves a copy number variation in the TPSAB1-gene. Its role as standalone multisystem syndrome is heavily debated. There is emerging evidence suggesting there might be a link between HaT and due to the increased prevalence of HaT in patients with SM. The aim of this review is to provide a practical roadmap for diagnosis and management of mastocytosis and its associated entities, since there are still many misconceptions about these topics.Abbreviations: AdvSM: Advanced systemic mastocytosis; ASM: Aggressive systemic mastocytosis; aST: acute serum tryptase; BM: Bone marrow; BMM: Bone marrow mastocytosis; bST: baseline serum tryptase; CM: Cutaneous mastocytosis; DCM: Diffuse cutaneous mastocytosis; HVA: Hymenoptera venom allergy; HaT: Hereditary alpha tryptasemia; ISM: Indolent systemic mastocytosis; MC: Mast cell; MCA: Mast cell activation; MCAS: Mast cell activation syndrome; MCL: Mast cell leukemia; MIS: Mastocytosis in the skin; MMAS: Monoclonal mast cell activation syndrome; MPCM: Maculopapular cutaneous mastocytosis; SM: Systemic mastocytosis; SM-AHN: Systemic mastocytosis with associated hematological neoplasm; SSM: Smouldering systemic mastocytosis; VIT: Venom immunotherapy.

Overexpression of FcεRI on Bone Marrow Mast Cells, but Not MRGPRX2, in Clonal Mast Cell Disorders With Wasp Venom Anaphylaxis

Background

Uncertainties remain about the molecular mechanisms governing clonal mast cell disorders (CMCD) and anaphylaxis.

Objective

This study aims at comparing the burden, phenotype and behavior of mast cells (MCs) and basophils in patients with CMCD with wasp venom anaphylaxis (CMCD/WVA⁺), CMCD patients without anaphylaxis (CMCD/ANA^-), patients with an elevated baseline serum tryptase (EBST), patients with wasp venom anaphylaxis without CMCD (WVA⁺) and patients with a non-mast cell haematological pathology (NMHP).

Methods

This study included 20 patients with CMCD/WVA⁺, 24 with CMCD/ANA^-, 19 with WVA⁺, 6 with EBST and 5 with NMHP. We immunophenotyped MCs and basophils and compared baseline serum tryptase (bST) and both total and venom specific IgE in the different groups. For basophil studies, 13 healthy controls were also included.

Results

Higher levels of bST were found in CMCD patients with wasp venom anaphylaxis, CMCD patients without anaphylaxis and EBST patients. Total IgE levels were highest in patients with wasp venom anaphylaxis with and without CMCD. Bone marrow MCs of patients with CMCD showed lower CD117 expression and higher expression of CD45, CD203c, CD63, CD300a and FcεRI. Within the CMCD population, patients with wasp venom anaphylaxis showed a higher expression of FcεRI as compared to patients without anaphylaxis. Expression of MRGPRX2 on MCs did not differ between the study populations. Basophils are phenotypically and functionally comparable between the different patient populations.

Conclusion

Patients with CMCD show an elevated burden of aberrant activated MCs with a significant overexpression of FcεRI in patients with a wasp venom anaphylaxis.

Diagnosis of Primary Mast Cell Disorders in Anaphylaxis: Value of KIT D816V in Peripheral Blood

BACKGROUND

Anaphylaxis is frequent in patients suffering from primary mast cell disorders (PMCDs). In patients without mastocytosis in the skin (MIS) and a baseline serum tryptase (bST) less than 30 ng/mL, the diagnosis of PMCD is challenging. In these patients, detection of the KIT D816V mutation in peripheral blood (PB) has been suggested as screening tool for a PMCD.

OBJECTIVE

In this study, we investigated whether KIT D816V in PB can contribute to the decision to perform a bone marrow (BM) biopsy in patients with anaphylaxis without MIS and a bST less than 30 ng/mL.

METHODS

We selected 74 patients with severe anaphylaxis without MIS and a bST less than 30 ng/mL. All underwent a BM biopsy. KIT D816V mutation was quantified in both PB and BM using digital droplet polymerase chain reaction (ddPCR).

RESULTS

Diagnosis of a PMCD was established in 40 patients (54%). Median bST for patients with and without PMCD was, respectively, 9.5 ng/mL (range 4.2-27 ng/mL) and 4.9 ng/mL (range 2.2-20.3 ng/mL) (P <.001). KIT D816V in PB was detected in 16 out of 40 (40%) patients with PMCD. KIT D816V in BM was detected in 22 out of 40 (55%) patients with PMCD.

CONCLUSIONS

In patients without MIS and a bST less than < 30 ng/mL who experience anaphylaxis, determination of KIT D816V mutation in PB is of limited help in deciding when to proceed to a BM biopsy. Therefore, KIT D816V in PB mutation analysis should be interpreted together with scoring tools to make a better assessment in identifying patients who should undergo BM biopsy.

Cross-Cultural Adaptation and Psychometric Evaluation of the Dutch Version of the Work Rehabilitation Questionnaire (WORQ-VL)

Purpose The Work Rehabilitation Questionnaire (WORQ) was developed to evaluate work functioning in vocational rehabilitation, but was not yet available in Dutch. The goal of this study is twofold: a description of the cross-cultural adaptation process (part 1) of the WORQ to be used in Flanders (The Dutch speaking part of Belgium, WORQ-VL) and a presentation of the first psychometric testing of the WORQ-VL (part 2). Methods For part 1, the guidelines for cross-cultural adaptation of self-report measures by Beaton et al. were used to structure the cross-cultural adaptation. For part 2, a cross-sectional study was conducted in patients with musculoskeletal disorders [sample A: hand and wrist rehabilitation (n = 21) and sample B: fibromyalgia patients (n = 93)] who completed the WORQ-VL. Internal consistency and factor structure were examined in the total sample, whereas convergent and discriminant validity of the WORQ-VL were researched in sample A. Results First results on the convergent validity and discriminant validity (small sample size) and internal consistency of the WORQ-VL are promising. The exploratory factor analysis revealed seven factors which were labeled as 'cognition', 'physical', 'mood', 'activities of daily living', 'sensory', 'emotional' and 'social'. The best evidence was found for the 'physical' subscale of the WORQ-VL: strong correlations were found with the 'physical functioning' and 'role limitations-physical' subscales of the Short-Form Health Survey, respectively r = - .84 and r = - .59, p < .01. As expected, predominantly weak correlations were found with hand grip strength, kinesiophobia, hand-related aesthetics and satisfaction (ranging between r = - .38 and r = .34, p > .05). Conclusions The WORQ-VL is a user-friendly and valuable ICF-based self-report questionnaire to evaluate work functioning. Future studies are highly needed to examine the value of the WORQ within different patient populations and settings in order to examine further the added value of this self-report measure.

The Salmonella Enteritidis TolC outer membrane channel is essential for egg white survival

Salmonella Enteritidis has developed the potential to contaminate eggs by surviving in the antimicrobial environment of the hen's egg white. This has led to a worldwide pandemic of foodborne salmonellosis infections in humans due to the consumption of contaminated eggs and egg-derived products. The molecular mechanisms of Salmonella Enteritidis egg white survival are not fully clear. Using in vivo expression technology and promoter-reporter fusions we showed that the promoter of the tolC gene, encoding the TolC outer membrane channel that is used by multidrug efflux pumps to export harmful molecules and to secrete bacterial products, is activated by egg white at the chicken body temperature. Using a Salmonella Enteritidis tolC deletion mutant we showed that TolC has an important role in egg white survival. Chromatographic separation techniques and subsequent testing of antimicrobial activities of separated egg white fractions led to the identification of ovotransferrin as the egg white antimicrobial factor which is capable of inhibiting growth of a tolC deletion strain but not the wild type strain. We provide evidence that TolC protects Salmonella Enteritidis against ovotransferrin-mediated growth inhibition in egg white.

[Behavioral phenotypes and recent developments in genetic technologies]

Recent developments in genetic technologies make it possible to find a causative genetic defect in about 60% of patients diagnosed with neurodevelopmental disorders. A genetic etiology may provide insight into associated psychopathology, somatic comorbidity, course and direction for treatment.<br/> AIM: To provide an overview of recent developments in genetic technologies, of genetic syndromes and their associated psychopathology. This is illustrated by describing two recently described syndromes.<br/> METHOD: Clinical expertise combined with a search in Pubmed with the key words 'behavioural phenotype', 'intellectual disabilit*', 'next generation sequencing', 'exome' and 'genome'.<br/> RESULTS: We provide an overview of developments in genetic technologies. A schematic overview of syndromes, which may present in clinical practice, is offered and completed with implications for treatment. Findings in recently reported syndromes are illustrated.<br/> CONCLUSION: There is an increase in genetic diagnosis in patients with neurodevelopmental disorders. Knowledge about recent developments in genetics is helping psychiatrists to deal with considerations about referral for genetic diagnostics and putting a genetic syndrome in the context of psychiatric treatment.

Updating the Evidence on Functional Capacity Evaluation Methods: A Systematic Review

Objectives To synthesize the evidence on the psychometrics functional capacity evaluation (FCE) methods. Methods A systematic literature search in nine databases. The resulting articles were screened based on predefined in- and exclusion criteria. Two reviewers independently performed this screening. Included studies were appraised based on their methodological quality. Results The search resulted in 20 eligible studies about nine different FCE methods. The Baltimore Therapeutic Equipment work simulator showed a moderate predictive validity. The Ergo-Kit (EK) showed moderate variability and high inter- and intra-rater reliability. Low discriminative abilities and high convergent validity were found for the EK. Concurrent validity of the EK and the ERGOS Work Simulator was low to moderate. Moderate to high test-retest, inter- and intra-reliability was found in the Isernhagen Work-Systems (IWS) FCE. The predictive validity of the IWS was low. The physical work performance evaluation (PWPE) showed moderate test-retest reliability and moderate to high inter-rater reliability. Low internal and external responsiveness were found for the PWPE, predictive validity was high. The predictive validity of the short-form FCE was also high but need to be further examined on several psychometric properties. Low discriminative and convergent validity were found for the work disability functional assessment battery. The WorkHab showed moderate to high test-retest, inter- and intra-rater reliability. Conclusion Well-known FCE methods have been rigorously studied, but some of the research indicates weaknesses in their reliability and validity. Future research should address how these weaknesses can be overcome.

Reduced particle size wheat bran is butyrogenic and lowers Salmonella colonization, when added to poultry feed

Feed additives, including prebiotics, are commonly used alternatives to antimicrobial growth promoters to improve gut health and performance in broilers. Wheat bran is a highly concentrated source of (in)soluble fiber which is partly degraded by the gut microbiota. The aim of the present study was to investigate the potential of wheat bran as such to reduce colonization of the cecum and shedding of Salmonella bacteria in vivo. Also, the effect of particle size was evaluated. Bran with an average reduced particle size of 280μm decreased levels of cecal Salmonella colonization and shedding shortly after infection when compared to control groups and groups receiving bran with larger particle sizes. In vitro fermentation experiments revealed that bran with smaller particle size was fermented more efficiently, with a significantly higher production of butyric and propionic acid, compared to the control fermentation and fermentation of a larger fraction. Fermentation products derived from bran with an average particle size of 280μm downregulated the expression of hilA, an important invasion-related gene of Salmonella. This downregulation was reflected in an actual lowered invasive potential when Salmonella bacteria were pretreated with the fermentation products derived from the smaller bran fraction. These data suggest that wheat bran with reduced particle size can be a suitable feed additive to help control Salmonella infections in broilers. The mechanism of action most probably relies on a more efficient fermentation of this bran fraction and the consequent increased production of short chain fatty acids (SCFA). Among these SCFA, butyric and propionic acid are known to reduce the invasion potential of Salmonella bacteria.

Bone Marrow-Derived Progenitor Cells Are Functionally Impaired in Ischemic Heart Disease

To determine whether the presence of ischemic heart disease (IHD) per se, or rather the co-presence of heart failure (HF), is the primum movens for less effective stem cell products in autologous stem cell therapy, we assessed numbers and function of bone marrow (BM)-derived progenitor cells in patients with coronary artery disease (n = 17), HF due to ischemic cardiomyopathy (n = 8), non-ischemic HF (n = 7), and control subjects (n = 11). Myeloid and erythroid differentiation capacity of BM-derived mononuclear cells was impaired in patients with underlying IHD but not with non-ischemic HF. Migration capacity decreased with increasing IHD severity. Hence, IHD, with or without associated cardiomyopathy, is an important determinant of progenitor cell function. No depletion of hematopoietic and endothelial progenitor cells (EPC) within the BM was observed, while circulating EPC numbers were increased in the presence of IHD, suggesting active recruitment. The observed myelosuppression was not driven by inflammation and thus other mechanisms are at play.

Detection of a case of chronic myeloid leukaemia with deletions at the t(9;22) translocation breakpoints by a genome-wide non-invasive prenatal test

OBJECTIVE

Non-invasive prenatal tests (NIPTs) interrogating the complete genome are able to detect not only fetal trisomy 13, 18 or 21 but additionally provide information on other (sub)chromosomal aberrations that can be fetal or maternal in origin. We demonstrate that in a subset of cases, this information is clinically relevant and should be reported to ensure adequate follow-up.

METHOD

Genome-wide NIPT was carried out and followed by a software analysis pipeline optimized to detect subchromosomal aberrations.

RESULTS

The NIPT profile showed deletions on chromosomes 9 and 22: NIPT 9q33.3q34.12(129150001-133750000)x1,22q11.23(23550001-25450000)x1,22q13.1(37850001-39600000)x1. This result was confirmed by single nucleotide polymorphism array on maternal genomic DNA, which also demonstrated that the deletions were somatic in nature. Fluorescence in situ hybridization and quantitative real-time polymerase chain reaction revealed that the deletions were flanking the translocation breakpoint on the derivative chromosome 9 as the result of a t(9;22)(q34;q11.2) translocation with BCR-ABL1 fusion typical for chronic myeloid leukaemia (CML). Multidisciplinary counselling, together with complete blood count, taught that the woman was in an early chronic phase CML. The woman was followed up closely, and treatment could be postponed until after delivery.

CONCLUSION

Genome-wide NIPT identified a CML in chronic phase caused by the typical t(9;22)(q34;q11.2) translocation and accompanied by deletions flanking the translocation breakpoints. © 2016 John Wiley & Sons, Ltd.

Intraoperative administered tramadol reduces the need for piritramide in the immediate postoperative period in children undergoing adenotonsillectomy: A retrospective observational study

PURPOSE

Adenotonsillectomy is a frequently performed procedure in pediatric day-case surgery causing significant pain for which adequate analgesia is required. Our aim was to investigate if the intraoperative administration of IV tramadol decreases the need for postoperative pain medication in children. Because tramadol has well-known pro-emetic effects, we also assessed the incidence of postoperative nausea and vomiting (PONV).

METHODS

We performed a retrospective observational study in 314 children aged 1-13 years undergoing elective adenotonsillectomy. We identified 160 children who had received standard pain medication consisting of IV paracetamol and ketorolac and compared them with a group of 154 children who had received in addition a perioperative infusion of tramadol.

RESULTS

32.5% of the patients in the tramadol group versus 83.8% of the patients in the standard group required postoperative administration of piritramide (p < 0.0001). Groups did not differ with respect to the postoperative need for anti-emetics but in the tramadol group more patients had received prophylactic therapy with odansetron or dexamethasone (P < 0.0001).

CONCLUSION

The results of this retrospective study indicate that intraoperative tramadol administration in combination with prophylactic antiemetic therapy decreases the need for piritramide in the immediate postoperative period without increasing the incidence of PONV after tonsillectomy in children.

Concomitant Intraspinal and Retroperitoneal Hemorrhage Caused by an Aneurysm on the Celiac Artery: A Case Report

Spontaneous spinal hemorrhage is a rare condition. We present a case in which the diagnosis was complicated by a concomitant intra-abdominal hemorrhage. The patient, taking coumarins, presented with acute back pain and abdominal pain and progressive paresis of the lower limbs. Computed tomography angiography of the abdomen showed an intra-abdominal hemorrhage and an aneurysm of the celiac trunk. MR (magnetic resonance) imaging of the spine revealed a combined subdural and epidural hemorrhage from C1 to L1. Both sites were treated conservatively. After 6 months the patient regained strength in both legs with some persistent loss of strength in the left leg. Follow-up MR imaging showed complete resolution of the spinal hemorrhage. The celiac artery aneurysm was treated conservatively. We suggest that the rupture of the celiac artery aneurysm caused increased intra-abdominal pressure leading to spinal hemorrhage. Emergency staff should be aware of the possibility of two rare but concomitant conditions.

[Somatic screening in child and adolescent psychiatry: a descriptive pilot study]

BACKGROUND

Somatic disorders occur more often in psychiatric patients than in the general population. Somatic symptoms can cause or increase psychiatric symptoms. Psychiatric symptoms and their treatment can have an effect on the physical state of the patient. A pilot study involving an adult outpatient population has demonstrated that 62% of the patients studied had new clinically relevant symptoms. So far, no other data are available relating to somatic screening in child and adolescent psychiatry.

AIM

To assess whether somatic screening of children and adolescents newly referred to a department of child and adolescent psychiatry in the Netherlands gives added value to the diagnosis and treatment policy.

METHOD

In a pilot study 43 newly referred patients aged between 6 and 18 were screened by means of somatic history, a physical examination and blood parameters. On this basis we could calculate the percentage of somatic symptoms and , where necessary, follow-up treatment could be applied.

RESULTS

One or more clinically relevant disorders were found in almost 56% of the children and adolescents investigated. The disorders included dysmorphic anomalies, weight and height deviations, raised thyroid hormone levels, dyslipidaemia, anaemia and vitamin D and B12 deficiency. Advice about a healthy lifestyle was given to 44% of the patients. An antipsychotic medication in 25% of the patients was changed, in the case of 16% of the patients a family doctor was contacted about subsequent treatment and 19% of the patients were referred to a medical specialist.

CONCLUSION

Although the results of the pilot study indicate that somatic screening does provide added value, more research is needed in order to optimise the screening procedure.

A hypogranular variant of acute promyelocytic leukaemia showing a heterogenic immunophenotype with CD34, CD2, HLA-DR positivity: a case report and review of the literature

We report the case of a 46-year-old man who presented with the hypogranular variant of an acute promyelocytic leukaemia (APL). RT-PCR analysis for detection of the t(15;17) fusion transcript confirmed the cytological findings by demonstrating a bcr-3 type PML/RARalpha rearrangement. According to the WHO-classification, this leukaemia fulfilled the criteria for 'Acute promyelocytic leukaemia with t(15;17)(q22;q12)'(1). Immunophenotyping revealed a leukaemic population with an aberrant expression of markers. Besides the presence of the expected immunophenotypic markers in APL (CD45 with low density, CD13+, CD33+, CD15-, CD117+ and MPO+), the population showed a positivity for CD34, CD2 and HLA-DR for at least a part of the malignant promyelocytes. Since the expression of these three markers, all together, is rather unique, we reviewed the literature to prove the relationship of this specific immunophenotype with morphology, clinical and molecular findings.

Relationship of the Scarf valgus-inducing osteotomy of the calcaneus to the medial neurovascular structures

BACKGROUND

The Scarf valgus inducing osteotomy of the calcaneus is an operative technique to correct varus deformity of the hindfoot. It is versatile with significant corrective power; however, the neurovascular structures are in close proximity on the medial side and thus may be harmed during the osteotomy. Moreover, because this type of osteotomy can cause a great lateral translation, traction of the medial neurovascular structures is possible. We performed an anatomic study to evaluate the medial soft tissues after a lateralizing Scarf-type calcaneal osteotomy.

MATERIALS AND METHODS

The osteotomies were carried out on ten fresh-frozen cadaver specimens. We performed the osteotomy and induced valgus. Then we performed a medial dissection to identify the important medial structures: the medial and lateral plantar nerve (MPN , LPN) and the posterior tibial artery (PTA). We noted their relation to the osteotomy and their integrity.

RESULTS

In several cases, one or more of the structures were sectioned. In five cases, all the structures crossed the osteotomy, four of which even a transection of one or both of the plantar nerves occurred. Although the PTA crossed the osteotomy in eight specimens, there was no transection of this structure.

CONCLUSION

Scarf osteotomy of the calcaneus is a highly corrective osteotomy. However, caution must be exercised when performing as the medial neurovascular structures cross the osteotomy lines and transection can occur.

CLINICAL RELEVANCE

When performing the osteotomy one should keep in mind that vigorous sawing and large displacement can cause damage to the medial neurovascular structures.

Accuracy of tympanic and infrared skin thermometers in children

BACKGROUND

Rectal measurement is considered a gold standard in many healthcare systems for body temperature measurement in children. Although this method has several disadvantages, an ideal alternative thermometer has not yet been introduced. However tympanic and infrared skin thermometers are potential alternatives.

METHODS

A prospective cohort study was performed including 100 children between 0 and 18 years of age admitted to the general paediatric ward of Spaarne Hospital in The Netherlands between January and March 2009. The objectives of this study are to evaluate the accuracy of tympanic and two types of infrared skin thermometers (Beurer and Thermofocus) compared to rectal measurement and furthermore to evaluate the influence of different variables on temperature measurements.

RESULTS

Compared to rectal measurement (37.56°C), the mean temperatures of the tympanic (37.29°C), Beurer (36.79°C) and Thermofocus (37.30°C) thermometers differed significantly (p<0.001). Mean and SD of differences between rectal temperature and temperature measured with these alternative devices varied significantly (p<0.001). Sensitivity, specificity, positive and negative predictive values for detecting rectal fever measured with the tympanic, Beurer and Thermofocus thermometers are unacceptable, especially for the Beurer thermometer. This difference in temperature between rectal and the alternative thermometers remained after stratification on gender, age, skin colour and otoscopic abnormalities.

CONCLUSIONS

In this study the authors demonstrated that the tympanic, Beurer and Thermofocus thermometers cannot reliably predict rectal temperature. Therefore the authors do not advise replacement of rectal measurement as the gold standard for detecting fever in children by one of these devices. When rectal measurement is not used, the infrared skin thermometers appear to perform less well than tympanic measurements.

Induction of complete and molecular remissions in acute myeloid leukemia by Wilms' tumor 1 antigen-targeted dendritic cell vaccination

Active immunization using tumor antigen-loaded dendritic cells holds promise for the adjuvant treatment of cancer to eradicate or control residual disease, but so far, most dendritic cell trials have been performed in end-stage cancer patients with high tumor loads. Here, in a phase I/II trial, we investigated the effect of autologous dendritic cell vaccination in 10 patients with acute myeloid leukemia (AML). The Wilms' tumor 1 protein (WT1), a nearly universal tumor antigen, was chosen as an immunotherapeutic target because of its established role in leukemogenesis and superior immunogenic characteristics. Two patients in partial remission after chemotherapy were brought into complete remission after intradermal administration of full-length WT1 mRNA-electroporated dendritic cells. In these two patients and three other patients who were in complete remission, the AML-associated tumor marker returned to normal after dendritic cell vaccination, compatible with the induction of molecular remission. Clinical responses were correlated with vaccine-associated increases in WT1-specific CD8+ T cell frequencies, as detected by peptide/HLA-A*0201 tetramer staining, and elevated levels of activated natural killer cells postvaccination. Furthermore, vaccinated patients showed increased levels of WT1-specific IFN-gamma-producing CD8+ T cells and features of general immune activation. These data support the further development of vaccination with WT1 mRNA-loaded dendritic cells as a postremission treatment to prevent full relapse in AML patients.

Guidelines for an integrated diagnostic approach of chronic lymphoproliferative disorders in the routine laboratory of haematology in Belgium

This paper summarizes the minimal workout of chronic lymphoproliferative disorders in a routine laboratory of haematology as recommended by a team of experienced laboratory supervisors in Belgium, taking into account the specific organisation of healthcare in Belgium, the innovations in the field of molecular analyses and related reimbursement. The starting point was essentially based upon clinical and/or haematological indications and it is emphasized that conclusions should be drawn in close dialogue with the clinician and experts in cytogenetics and histopathology. Reports made in the laboratory should be based upon an integration of cytomorphological, immunophenotypical and molecular data. These guidelines are not intended to be used as universal 'diagnostic pathways', but should be useful in developing local diagnostic pathways. It is well understood that this consensus, being valid anno 2009, may rapidly change with new technologies being introduced and new targets discovered.

A maximal exercise bout increases the number of circulating CD34+/KDR+ endothelial progenitor cells in healthy subjects. Relation with lipid profile

Mobilization of bone marrow-derived endothelial progenitor cells (EPC) might explain exercise-induced improvement of endothelial function. We assessed whether a maximal exercise bout could alter the number of circulating EPC in healthy subjects and whether this effect is related to their cardiovascular risk profile. Additionally, we investigated possible mediators of this effect, namely nitric oxide (NO) bioavailability and vascular endothelial growth factor (VEGF) release. Healthy subjects (group 1, n = 11; group 2, n = 14) performed a symptom-limited cardiopulmonary exercise test on a bicycle ergometer. Numbers of CD34+/kinase insert domain receptor (KDR)+ cells were determined by flow-cytometric analysis, either after magnetic separation of CD34+ cells (group 1) or starting from whole blood (group 2). Serum concentrations of VEGF and NO metabolites were measured by using ELISA. Following exercise, EPC increased by 76% (15.4 +/- 10.7 cells/ml vs. 27.2 +/- 13.7 cells/ml; P = 0.01) in group 1 and by 69% in group 2 (30.9 +/- 14.6 cells/ml vs. 52.5 +/- 42.6 cells/ml; P = 0.03). The increase in EPC correlated positively with LDL and total cholesterol/HDL ratio and negatively with peak oxygen consumption and oxygen consumption at anaerobic threshold. VEGF levels increased with exercise, with a strong trend toward significance (P = 0.055). NO levels remained unchanged. The present study demonstrates that a maximal bout of exercise induces a significant shift in CD34+ cells toward CD34+/KDR+ cells. This response was larger in subjects with a less favorable lipid profile.

Plasmid-based genetic modification of human bone marrow-derived stromal cells: analysis of cell survival and transgene expression after transplantation in rat spinal cord

Background

Bone marrow-derived stromal cells (MSC) are attractive targets for ex vivo cell and gene therapy. In this context, we investigated the feasibility of a plasmid-based strategy for genetic modification of human (h)MSC with enhanced green fluorescent protein (EGFP) and neurotrophin (NT)3. Three genetically modified hMSC lines (EGFP, NT3, NT3-EGFP) were established and used to study cell survival and transgene expression following transplantation in rat spinal cord.

Results

First, we demonstrate long-term survival of transplanted hMSC-EGFP cells in rat spinal cord under, but not without, appropriate immune suppression. Next, we examined the stability of EGFP or NT3 transgene expression following transplantation of hMSC-EGFP, hMSC-NT3 and hMSC-NT3-EGFP in rat spinal cord. While in vivo EGFP mRNA and protein expression by transplanted hMSC-EGFP cells was readily detectable at different time points post-transplantation, in vivo NT3 mRNA expression by hMSC-NT3 cells and in vivo EGFP protein expression by hMSC-NT3-EGFP cells was, respectively, undetectable or declined rapidly between day 1 and 7 post-transplantation. Further investigation revealed that the observed in vivo decline of EGFP protein expression by hMSC-NT3-EGFP cells: (i) was associated with a decrease in transgenic NT3-EGFP mRNA expression as suggested following laser capture micro-dissection analysis of hMSC-NT3-EGFP cell transplants at day 1 and day 7 post-transplantation, (ii) did not occur when hMSC-NT3-EGFP cells were transplanted subcutaneously, and (iii) was reversed upon re-establishment of hMSC-NT3-EGFP cell cultures at 2 weeks post-transplantation. Finally, because we observed a slowly progressing tumour growth following transplantation of all our hMSC cell transplants, we here demonstrate that omitting immune suppressive therapy is sufficient to prevent further tumour growth and to eradicate malignant xenogeneic cell transplants.

Conclusion

In this study, we demonstrate that genetically modified hMSC lines can survive in healthy rat spinal cord over at least 3 weeks by using adequate immune suppression and can serve as vehicles for transgene expression. However, before genetically modified hMSC can potentially be used in a clinical setting to treat spinal cord injuries, more research on standardisation of hMSC culture and genetic modification needs to be done in order to prevent tumour formation and transgene silencing in vivo.

Acute myeloid leukaemia of mixed megakaryocytic and erythroid origin: a case report and review of the literature

We report the case of a 78-year-old man who presented with acute myeloid leukaemia showing subpopulations of cells expressing platelet-associated markers and the presence of a pan-myeloid component, besides glycophorin A-positive cells. Most of the immature cells had a proerythroblast-like morphology and we classified this case as an FAB-M6 variant, as suggested by Bain (1). According to the WHO classification, this leukaemia fulfilled the criteria of'AML with multilineage dysplasia' (2). Immunophenotyping characteristics showed two distinct aberrant subpopulations, a young pan-myeloid (CD45+ with low density, CD34+, CD117+, CD13+, CD33+, partial cytoplasmic myeloperoxidase (MPO)+) population with platelet-associated markers (CD41+, CD42+, CD61+) and a CD45+, CD117+, CD34- population with partial CD235a positivity indicative for erythroid maturation. This case belongs to the group of 'early' erythroblastic leukaemias where a subset of progenitor cells present with erythroid-megakaryocyte bipotentiality or are blocked at an early BFU-E (burst-forming unit erythrocyte)-like stage of erythroid differentiation (11, 12, 13).

Does practice make perfect? An age-matched study on grand multiparity in Flanders, Belgium

AIM

To compare the perinatal outcome of grand multi-parous women (giving birth for the fifth to ninth time) and pauciparous (parity 2 to 4) women in the region of Flanders, Belgium.

METHODS

Population-based, retrospective, age-matched study.

RESULTS

2832 grand multiparous women were compared with 2832 pauciparous women. In univariate analysis grand multiparous women showed more transverse lie, macrosomia, and fetal death and had less frequently epidural analgesia and episiotomy. Logistic regression demonstrated that grand multiparity was a significant factor contributing to fetal death and macrosomia.

CONCLUSION

Grand multiparity is associated with fetal death and macrosomia in the region of Flanders, Belgium.

Apoptosis: mechanisms and relevance in cancer

Apoptosis or programmed cell death is a process with typical morphological characteristics including plasma membrane blebbing, cell shrinkage, chromatin condensation and fragmentation. A family of cystein-dependent aspartate-directed proteases, called caspases, is responsible for the proteolytic cleavage of cellular proteins leading to the characteristic apoptotic features, e.g. cleavage of caspase-activated DNase resulting in internucleosomal DNA fragmentation. Currently, two pathways for activating caspases have been studied in detail. One starts with ligation of a death ligand to its transmembrane death receptor, followed by recruitment and activation of caspases in the death-inducing signalling complex. The second pathway involves the participation of mitochondria, which release caspase-activating proteins into the cytosol, thereby forming the apoptosome where caspases will bind and become activated. In addition, two other apoptotic pathways are emerging: endoplasmic reticulum stress-induced apoptosis and caspase-independent apoptosis. Naturally occurring cell death plays a critical role in many normal processes like foetal development and tissue homeostasis. Dysregulation of apoptosis contributes to many diseases, including cancer. On the other hand, apoptosis-regulating proteins also provide targets for drug discovery and new approaches to the treatment of cancer.

Immunotoxicology in wood mice along a heavy metal pollution gradient

We carried out an immunotoxicological field study of wood mice in three populations along a heavy metal pollution gradient. Heavy metal concentrations in liver tissue indicated that exposure to silver, arsenic, cadmium, cobalt and lead decreased with increasing distance from a non-ferrous smelter. Host resistance to the endoparasite Heligmosomoides polygyrus decreased with increasing exposure, while the abundance of tick larvae and the nematode Syphacia stroma was unrelated to heavy metal exposure. Spleen mass was increased at the intermediate and the most polluted sites and was positively correlated with the number of H. polygyrus and tick larvae. Proportion of early apoptotic leukocytes increased towards the smelter and was positively related to cadmium exposure. Red and white blood cell counts and lysozyme activity showed no relationship with metal exposure. All together, our observations suggest negative effects of heavy metal exposure on the immune function of wood mice under field conditions.

Cell cycle effect of gemcitabine and its role in the radiosensitizing mechanism in vitro

PURPOSE

The mechanism of radiosensitization by gemcitabine is still unclear. It has been hypothesized that the accumulation of cells in early S phase may play a role in enhancing radiosensitivity.

METHODS AND MATERIALS

The schedule dependency of the radiosensitizing effect was studied in ECV304, human bladder cancer cells, and H292, human lung cancer cells, by varying the incubation time and time interval between gemcitabine and radiation treatment. To determine the role of cell cycle perturbations in the radiosensitization, the influence of gemcitabine on the cell cycle at the moment of radiation was investigated by flow cytometry.

RESULTS

The radiosensitizing effect increased with a longer incubation period: Dose enhancement factors varied from 1.30 to 2.82 in ECV304 and from 1.04 to 1.78 in H292 after treatment during 8-32 h, respectively. Radiosensitization decreased with an increasing interval: Dose enhancement factors varied from 2.26 to 1.49 in ECV304 and from 1.45 to 1.11 in H292 after an interval 0-24 h, respectively. Cells were blocked in the early S phase of the cell cycle by gemcitabine. The highest percentage S-phase cells was observed after treatment with the schedules that resulted in the highest radiosensitizing effect.

CONCLUSIONS

We observed a clear schedule-dependent radiosensitization by gemcitabine. Our findings demonstrated a correlation between gemcitabine-induced early S-phase block and the radiosensitizing effect.

Cell cycle and apoptosis

Apoptosis and proliferation are intimately coupled. Some cell cycle regulators can influence both cell division and programmed cell death. The linkage of cell cycle and apoptosis has been recognized for c-Myc, p53, pRb, Ras, PKA, PKC, Bcl-2, NF-kappa B, CDK, cyclins and CKI. This review summarizes the different functions of the proteins presently known to control both apoptosis and cell cycle progression. These proteins can influence apoptosis or proliferation but different variables, including cell type, cellular environment and genetic background, make it difficult to predict the outcome of cell proliferation, cell cycle arrest or cell death. These important decisions of cell proliferation or cell death are likely to be controlled by more than one signal and are necessary to ensure a proper cellular response.

The cell cycle: a review of regulation, deregulation and therapeutic targets in cancer

The cell cycle is controlled by numerous mechanisms ensuring correct cell division. This review will focus on these mechanisms, i.e. regulation of cyclin-dependent kinases (CDK) by cyclins, CDK inhibitors and phosphorylating events. The quality checkpoints activated after DNA damage are also discussed. The complexity of the regulation of the cell cycle is also reflected in the different alterations leading to aberrant cell proliferation and development of cancer. Consequently, targeting the cell cycle in general and CDK in particular presents unique opportunities for drug discovery. This review provides an overview of deregulation of the cell cycle in cancer. Different families of known CDK inhibitors acting by ATP competition are also discussed. Currently, at least three compounds with CDK inhibitory activity (flavopiridol, UCN-01, roscovitine) have entered clinical trials.

Plant cytokinin analogues with inhibitory activity on cyclin-dependent kinases exert their antiproliferative effect through induction of apoptosis initiated by the mitochondrial pathway: determination by a multiparametric flow cytometric analysis

OBJECTIVE

Regulation of the cell cycle by cyclin-dependent kinase (CDK) activity occurs at multiple levels and is often altered in human cancers. Therefore, CDK activity has been targeted for drug discovery, and a number of small molecules have now been identified as CDK inhibitors. Plant cytokinin analogues with CDK inhibitory activity and antiproliferative effects were studied to characterize the cellular basis of the cytotoxic effect.

METHODS

The IC(50) value (concentration at which 50% of the cell proliferation is inhibited) and AC(50) value (concentration at which 50% of the cell population is apoptotic) were determined by flow cytometry and microscopy, respectively. A new multiparametric flow cytometric analysis was used to study the sequence of different apoptotic events. In this assay, analysis of phosphatidylserine exposure, mitochondrial membrane depolarization, activation of caspases and DNA condensation were combined.

RESULTS

Treatment of Jurkat and KG1 cells with the CDK inhibitors results in a decrease of viable cells and a parallel increase in percentage of apoptotic cells. Apoptosis was accompanied by a rapid decrease of mitochondrial membrane potential, which precedes DNA condensation, exposure of phosphatidylserine and activation of caspases.

CONCLUSIONS

The main cellular mechanism of the antiproliferative effect of plant cytokinin analogues with CDK inhibitory activity is the induction of apoptosis. The multiparametric flow cytometric technique allowed to follow the kinetics of various aspects of apoptotic cell changes and demonstrated that cytokinin analogue-induced apoptosis starts through the mitochondrial pathway. This technique could also become of value for the rapid screening of pro-apoptotic properties of chemotherapeutic compounds.

Antiproliferative effect of plant cytokinin analogues with an inhibitory activity on cyclin-dependent kinases

In this study, analogues of olomoucine, a previously described plant cytokinin analogue with cyclin-dependent kinase (CDK) inhibitory activity, were investigated for effect on CDK1 and CDK2 and for effect on cell proliferation. Eight new compounds exhibit stronger inhibitory activity on CDK1 and CDK2 and on cell proliferation than olomoucine. Some active compounds showed low inhibition of proliferation of normal myeloid growth. Improvement of inhibitory activity of known compounds with a C6-benzylamino group was brought about by substitution with one hydroxyl. Also, new C2 substituents associated with inhibitory activity on CDK and on cell proliferation are described. There was a significant correlation between effect on CDK and antiproliferative effect on the KG1 and Molt3 cell lines and on primary human lymphocytes, strongly suggesting that at least part of the antiproliferative effect of cytokinin analogues was due to inhibition of CDK activity. Cytokinin analogues induced apoptosis in a time- and concentration-dependent manner and changes in cell cycle distribution. The antiproliferative and pro-apoptotic effects of plant cytokinin analogues suggest that they are a new class of cytostatic agents and that they may find an application in the chemotherapy of cancer.

Perineural antinociceptive effect of opioids in a rat model

BACKGROUND

The research on conductive analgesia induced by perineural opioids generated a large body of conflicting data. In this study we reassessed the antinociceptive response to perineural administration of morphine, fentanyl or meperidine in a rat model.

METHODS

Analgesia was assessed using the hind paw withdrawal latency (HPWL) response to radiant heat. The opioid dose producing 20% of maximal possible effect (20%MPE) for systemic analgesia was calculated for each drug. Then sciatic blockade was performed with the dose corresponding to 20%MPE. The injected hind paw was used to measure direct perineural effect and the contralateral hind paw was used as an indicator of systemic effect.

RESULTS

The response latency produced by morphine or fentanyl was not significantly different for ipsilateral (perineural effect) or contralateral (systemic effect) paw (27+/-11 vs. 28+/-16 and 3l+/-16 vs. 23+/-16 s, respectively). However, the meperidine group showed significantly higher %MPE for the ipsilateral paw (79+/-32 s) than for the contralateral paw (27+/-22 s).

CONCLUSIONS

The results indicate that perineural fentanyl or morphine do not produce analgesia. Perineural block produced by meperidine was attributed to local anesthetic-like effect, rather than to drug interaction with opioid receptor.

Evaluation of the discriminatory power of typing methods for Neisseria gonorrhoeae

A panel of 18 strains of Neisseria gonorrhoeae, known to be temporally and geographically diverse, was used to evaluate a number of typing systems, including conventional auxotyping and serotyping and the molecular methods of arbitrarily primed PCR (AP-PCR), amplified ribosomal-DNA restriction analysis (ARDRA), opa typing, and pulsed-field gel electrophoresis (PFGE). The discriminatory power of the different typing methods were determined with a collection of 87 clinical isolates from commercial sex workers in Indonesia, and Simpson's index of diversity was calculated. Of the two traditional techniques, auxotyping and serotyping, the latter gives the highest discriminatory index (DI) (DI, 0.846). The combination of auxotyping and serotyping yields a high DI (DI, 0. 928). D11344- and D8635-primed PCR showed low DIs of 0.608 and 0.622, respectively, but a combination of the two primers had a DI of 0. 849. The combination of serotyping with D11344-primed or D8635-primed PCR resulted in DIs of 0.936 and 0.937, respectively. ARDRA revealed a low DI of 0.743 alone but a DI of 0.955 in combination with serotyping. PFGE using the restriction enzyme BglII and opa typing produced the highest discrimination (DIs, 0.997 and 0. 996, respectively) for isolates of N. gonorrhoeae.

Prolonged analgesia and decreased toxicity with liposomal morphine in a mouse model

Inadequate control of postoperative pain remains a major clinical problem. A reliable method of providing long-lasting postoperative analgesia with a single dose would be very useful. We synthesized a liposomal morphine formulation and compared it to free morphine with regard to duration of analgesia in the mouse. Analgesia was assessed after intraperitoneal injection using the tail-flick test. The systemic toxicity after administration of liposomal and free morphine was compared. The release rate of morphine from liposomes in vitro was also evaluated. The lethal intraperitoneal dose of free morphine in 50% of mice (LD50) was 400 mg/kg. The maximum safe (non-lethal) dose of free morphine was 130 mg/kg. The highest dose of liposomal morphine administered (1650 mg/kg) did not cause death in any animal. Duration of analgesia was significantly prolonged with the highest dose of liposomal morphine (21.5 +/- 5.3 h) compared to the maximum safe dose of free morphine (3.7 +/- 0.75 h), P < 0.01. In vitro experiments showed a slow release rate of morphine from the liposome depot. Prolonged analgesia and decreased systemic toxicity for liposomal morphine are explained by sustained release of morphine from the liposomal depot. These results suggest that liposomal narcotic formulations may provide prolonged analgesia with single-dose administration.

Prolonged analgesia with liposomal bupivacaine in a mouse model

BACKGROUND AND OBJECTIVES

Currently available local anesthetics have relatively limited duration of action and some may cause severe systemic toxicity. An ultralong lasting local anesthetic would be useful to produce prolonged intraoperative anesthesia and extended postoperative analgesia. The goal of this study was to synthesize a sustained release local anesthetic formulation that would produce prolonged sensory block and decrease the possibility of systemic toxicity.

METHODS

The effect of liposomes containing 1.1% bupivacaine on duration of sensory block of the mouse tail was compared with equivalent concentrations of bupivacaine with and without epinephrine. Analgesia was assessed using the tail flick test. Systemic toxicity (LD50) was assessed after intraperitoneal injection and in vitro release rates were compared by dialysis technique for liposomal and plain bupivacaine.

RESULTS

Sensory block was significantly prolonged with liposomal bupivacaine (130 +/- 38 minutes) compared to plain bupivacaine (46 +/- 11 minutes, P < .01) or bupivacaine with epinephrine (81 +/- 28 minutes, P < .05). The LD50 was significantly lower for plain bupivacaine (61 mg/kg, 95% confidence intervals 47-79) than for liposomal bupivacaine (291 mg/kg, 95% confidence intervals 201-422). The time to 50% in vitro release through a dialysis membrane for liposomal bupivacaine (28 +/- 9 minutes) was markedly prolonged compared to plain bupivacaine (7 +/- 1 minutes).

CONCLUSIONS

This study shows that liposomal encapsulation of bupivacaine significantly prolongs duration of action and greatly decreases systemic toxicity of the drug. These findings may be promising for the future production of formulations of ultralong lasting local anesthetics with enhanced efficacy and safety.

Assessing local anesthetic effect using the mouse tail flick test

We used the tail flick test to quantify duration of local anesthetic-induced conduction block in the mouse. Using a baseline tail flick latency (TFL) between 1.0 and 2.5 sec, sensory block was considered present if TFL was > or = 4 sec. Two 20-microL local anesthetic injections were made on opposite sides of the tail base. TFL was tested every 10 min, and local block duration was interpreted as the time to return of TFL to < 4 sec. We tested three different concentrations of procaine (1%, 2%, and 4%), tetracaine (0.125%, 0.5%, and 1%), and lidocaine (0.5%, 1%, and 2%) with and without epinephrine. The testing method could discriminate between the duration of the various local anesthetic concentrations used. For the 1% concentrations, the duration of sensory block was 2 +/- 4 min (S.D.) for procaine, 20 +/- 10 min for lidocaine, 40 +/- 10 min for tetracaine, and 66 +/- 15 min for lidocaine with epinephrine. We found this to be a simple and reliable means of assessing local anesthetic conduction block in the mouse.

A rat sciatic nerve model for independent assessment of sensory and motor block induced by local anesthetics

The purpose of this study was to develop a reliable model to independently quantify motor and sensory block produced by local anesthetics. The sciatic nerve was blocked in 52 rats by injecting 0.2 mL of 0.125%, 0.25%, 0.5%, or 0.75% bupivacaine (n = 13 for each concentration). Accurate needle placement was achieved using a nerve stimulator at 0.2 mA and 1 Hz. Ten control rats received 0.9% saline (n = 5) or sham nerve stimulation (n = 5). Motor block was assessed by measuring hindpaw grip strength with a dynamometer. Sensory block was determined by measuring hindpaw withdrawal latency from radiant heat. The intensity of both motor and sensory block measured at 30-min intervals was plotted against time until full recovery to obtain the area under the curve. Intergroup comparisons using analysis of variance showed increasing area under the curve with increasing concentrations of bupivacaine for motor blocks (P < 0.05 for all intergroup comparisons except 0.5% vs 0.75%) and sensory blocks (P < 0.05 for all intergroup comparisons). Normal saline or sham nerve stimulation did not result in any motor or sensory block.