Twelve years of circulatory extracorporeal life support at the University Medical Centre Utrecht.

INTRODUCTION: Circulatory extracorporeal life support (ECLS) has been performed at the University Medical Centre Utrecht for 12 years. During this time, case mix, indications, ECLS set-ups and outcomes seem to have substantially changed. We set out to describe these characteristics and their evolution over time. METHODS: All patients receiving circulatory ECLS between 2007 and 2018 were retrospectively identified and divided into six groups according to a 2-year period of time corresponding to the date of ECLS initiation. General characteristics plus data pertaining to comorbidities, indications and technical details of ECLS commencement as well as in-hospital, 30-day, 1­year and overall mortality were collected. Temporal trends in these characteristics were examined. RESULTS: A total of 347 circulatory ECLS runs were performed in 289 patients. The number of patients and ECLS runs increased from 8 till a maximum of 40 runs a year. The distribution of circulatory ECLS indications shifted from predominantly postcardiotomy to a wider set of indications. The proportion of peripheral insertions with or without application of left ventricular unloading techniques substantially increased, while in-hospital, 30-day, 1­year and overall mortality decreased over time. CONCLUSION: Circulatory ECLS was increasingly applied at the University Medical Centre Utrecht. Over time, indications as well as treatment goals broadened, and cannulation techniques shifted from central to mainly peripheral approaches. Meanwhile, weaning success increased and mortality rates diminished.

IMARI: multi-Interventional program for prevention and early Management of Anastomotic leakage after low anterior resection in Rectal cancer patIents: rationale and study protocol.

BACKGROUND: Anastomotic leakage (AL) is still a common and feared complication after low anterior resection (LAR) for rectal cancer. The multifactorial pathophysiology of AL and lack of standardised treatment options requires a multi-modal approach to improve long-term anastomotic integrity. The objective of the IMARI-trial is to determine whether the one-year anastomotic integrity rate in patients undergoing LAR for rectal cancer can be improved using a multi-interventional program. METHODS: IMARI is a multicentre prospective clinical effectiveness trial, whereby current local practice (control cohort) will be evaluated, and subsequently compared to results after implementation of the multi-interventional program (intervention cohort). Patients undergoing LAR for rectal cancer will be included. The multi-interventional program includes three preventive interventions (mechanical bowel preparation with oral antibiotics, tailored full splenic flexure mobilization and intraoperative fluorescence angiography using indocyanine green) combined with a standardised pathway for early detection and active management of AL. The primary outcome is anastomotic integrity, confirmed by CT-scan at one year postoperatively. Secondary outcomes include incidence of AL, protocol compliance and association with AL, temporary and permanent stoma rate, reintervention rate, quality of life and functional outcome. Microbiome analysis will be conducted to investigate the role of the rectal microbiome in AL. In a Dutch nationwide study, the AL rate was 20%, with anastomotic integrity of 90% after one year. Based on an expected reduction of AL due to the preventive approaches of 50%, and increase of anastomotic integrity by a standardised pathway for early detection and active management of AL, we hypothesised that the anastomotic integrity rate will increase from 90 to 97% at one year. An improvement of 7% in anastomotic integrity at one year was considered clinically relevant. A total number of 488 patients (244 per cohort) are needed to detect this difference, with 80% statistical power. DISCUSSION: The IMARI-trial is designed to evaluate whether a multi-interventional program can improve long-term anastomotic integrity after rectal cancer surgery. The uniqueness of IMARI lies in the multi-modal design that addresses the multifactorial pathophysiology for prevention, and a standardised pathway for early detection and active treatment of AL. TRIAL REGISTRATION: Trialregister.nl ( NL8261 ), January 2020.

Risk factors for postoperative delirium after elective major abdominal surgery in elderly patients: A cohort study.

BACKGROUND: Prehabilitation programs have recently been suggested as potentially able to lower the incidence of delirium in elderly patients undergoing major abdominal surgery. For these prehabilitation programs to become successful, it is essential to identify those patients who are most likely to develop a delirium. MATERIAL AND METHODS: A single-centre cohort study was conducted. Inclusion criteria were: age ≥70 years and scheduled for abdominal surgery for colorectal cancer or an abdominal aortic aneurysm between January 2013 and June 2018. Baseline patient, surgical, anaesthesiologic and haematological characteristics were collected. A risk factor analysis was conducted, with postoperative delirium as primary outcome, by performing a multivariable logistic regression analysis. RESULTS: In this study, 627 patients were included, of whom 64 (10%) developed a delirium. Variables that differed significantly between delirious and non-delirious patients were age, burden of comorbidity, renal impairment, hypertension, cognitive impairment, history of delirium, physical and nutritional impairment, open surgery, preoperative anaemia and erythrocyte transfusion. After multivariable logistic regression analysis, risk factors for postoperative delirium after major abdominal surgery were renal impairment (OR 2.2; 95%CI 1.2-4.3), cognitive impairment (OR 4.1; 95%CI 1.8-9.2), an ASA score ≥ 3 (OR 2.0; 95% CI 1.0-3.9), being an active smoker (OR 2.7; 95%CI 1.3-5.8), ICU admission (OR 7.1; 95%CI 3.5-14.3), erythrocyte transfusion (OR 2.4; 95%CI 1.2-4.9) and a diagnosis of colorectal cancer (CRC); (OR 4.0; 95% CI 1.7-9.6). Prehabilitation had a protective effect (OR 0.5; 95% CI 0.3-0.9). CONCLUSION: Postoperative delirium is a frequent complication after major abdominal surgery in the elderly, especially in octogenarians and after open procedures. Renal impairment, cognitive impairment, being an active smoker, ICU admission, erythrocyte transfusion and a diagnosis of CRC are important risk factors for the development of delirium. Prehabilitation lowers the risk of developing a delirium.

Multimodal prehabilitation to reduce the incidence of delirium and other adverse events in elderly patients undergoing elective major abdominal surgery: An uncontrolled before-and-after study.

BACKGROUND: Delirium is a common and serious complication in elderly patients undergoing major abdominal surgery, with significant adverse outcomes. Successful strategies or therapies to reduce the incidence of delirium are scarce. The objective of this study was to assess the role of prehabilitation in reducing the incidence of delirium in elderly patients. METHODS: A single-center uncontrolled before-and-after study was conducted, including patients aged 70 years or older who underwent elective abdominal surgery for colorectal carcinoma or an abdominal aortic aneurysm between January 2013 and October 2015 (control group) and between November 2015 and June 2018 (prehabilitation group). The prehabilitation group received interventions to improve patients' physical health, nutritional status, factors of frailty and preoperative anaemia prior to surgery. The primary outcome was incidence of delirium, diagnosed with the DSM-V criteria or the confusion assessment method. Secondary outcomes were additional complications, length of stay, unplanned ICU admission, length of ICU stay, readmission rate, institutionalization, and in-hospital or 30-day mortality. RESULT: A total of 360 control patients and 267 prehabilitation patients were included in the final analysis. The mean number of prehabilitation days was 39 days. The prehabilitation group had a higher burden of comorbidities and was more physically and visually impaired at baseline. At adjusted logistic regression analysis, delirium incidence was reduced significantly from 11.7 to 8.2% (OR 0.56; 95% CI 0.32-0.98; P = 0.043). No statistically significant effects were seen on secondary outcomes. CONCLUSION: Current prehabilitation program is feasible and safe, and can reduce delirium incidence in elderly patients undergoing elective major abdominal surgery. This program merits further evaluation. TRIAL REGISTRATION: Dutch Trial Registration, NTR5932.

Variation in circumferential resection margin: Reporting and involvement in the South-Netherlands.

BACKGROUND: Since the introduction of total mesorectal surgery the outcome of rectal cancer patients has improved significantly. Involvement of the circumferential resection margin (CRM) is an important predictor of increased local recurrence, distant metastases and decreased overall survival. Abdomino perineal excision (APE) is associated with increased risk of CRM involvement. Aim of this study was to analyze reporting of CRM and to identify predictive factors for CRM involvement. METHODS: A population-based dataset was used selecting 2153 patients diagnosed between 2008 and 2013 with primary rectal cancer undergoing surgery. Variation in CRM reporting was assessed and predictive factors for CRM involvement were calculated and used in multivariate analyses. RESULTS: Large variation in CRM reporting was found between pathology departments, with missing cases varying from 6% to 30%. CRM reporting increased from 77% in 2008 to 90% in 2012 (p < 0.001). CRM involvement significantly decreased from 12% to 6% over the years (p < 0.001). In multivariate analysis type of operation, low anterior resection or APE, did not influence the risk of CRM involvement. Clinical T4-stage [odds ratio (OR) = 3.51; 95% confidence interval (CI) = 1.85-6.65) was associated with increased risk of CRM involvement, whereas neoadjuvant treatment (5 × 5 gray radiotherapy [OR 0.39; CI 0.25-0.62] or chemoradiation therapy [OR 0.30; CI 0.17-0.53]) were associated with significant decreased risk of CRM involvement. CONCLUSION: Although significant improvements are made during the last years there still is variation in reporting of CRM involvement in the Southern Netherlands. In multivariate analysis APE was no longer associated with increased risk of CRM involvement.

Postoperative delirium in elderly after elective and acute colorectal surgery: A prospective cohort study.

OBJECTIVE: To assess the frailty and the incidence of delirium in elderly patients undergoing elective and acute colorectal surgery in correlation with morbidity and mortality. METHODS: Patients aged 65 years and older having elective and acute colorectal surgery, between April 2013 and December 2013 were included in a prospective database. Patients diagnosed with a colorectal carcinoma or diverticulitis who were operated on were included. Factors that characterize frailty of patients were noted. The incidence rates of delirium after elective and acute surgery were recorded. Delirium was diagnosed using the Delirium Observation Screening Scale (DOSS). Preoperative evaluation, surgical outcome including morbidity, hospital stay and mortality were analyzed. RESULTS: Patients ≥ 65 years were included, 83 (75%) received elective and 28 (25%) acute surgery. The overall incidence of delirium was 21%, 18% for elective and 29% for patients having urgent surgery (p = 0.24). Patients with delirium were older than the non-delirious patients (median 82 years vs. 74 years; p < 0.001). Delirious patients showed higher incidence of adverse events. Hospital stay, mortality and discharge to a nursing home were significant higher in the delirious compared to the non-delirious group (p = 0.01; 0.01; 0.02 respectively). CONCLUSION: High incidence of delirium was found in both acute and elective colorectal surgery. Delirium was associated with adverse outcomes.

Personalized Coaching Systems to support healthy behavior in people with chronic conditions.

Chronic conditions cannot be cured but daily behavior has a major effect on the severity of secondary problems and quality of life. Changing behavior however requires intensive support in daily life, which is not feasible with a human coach. A new coaching approach - so-called Personal Coaching Systems (PCSs) - use on-body sensing, combined with smart reasoning and context-aware feedback to support users in developing and maintaining a healthier behavior. Three different PCSs will be used to illustrate the different aspects of this approach: (1) Treatment of neck/shoulder pain. EMG patterns of the Trapezius muscles are used to estimate their level of relaxation. Personal vibrotactile feedback is given, to create awareness and enable learning when muscles are insufficiently relaxed. (2) Promoting a healthy activity pattern. Using a 3D accelerometer to measure activity and a smartphone to provide feedback. Timing and content of the feedback are adapted real-time, using machine-learning techniques, to optimize adherence. (3) Management of stress during daily living. The level of stress is quantified using a personal model involving a combination of different sensor signals (EMG, ECG, skin conductance, respiration). Results show that Personal Coaching Systems are feasible and a promising and challenging way forward to coach people with chronic conditions.

A close look at postoperative fluid management and electrolyte disorders after gastrointestinal surgery in a teaching hospital where patients are treated according to the ERAS protocol.

PURPOSE: To evaluate the routine postoperative fluid management in relation to the British Consensus Guidelines on Intravenous Fluid Therapy for Adult Surgical Patients 2008 by the assessment of the fluid overload and electrolyte disorders in patients who were postoperatively treated according to an 'enhanced recovery after surgery' (ERAS) protocol. METHODS: All liver, pancreatic and gastrointestinal surgical patients treated during a 10-week period were consecutively included in this analysis. All patients were treated according to a fast track protocol. Fluid balance charts and electrolyte disorders were recorded. Electrolyte disorders were reported based on the laboratory results. RESULTS: A total of 71 patients with an uncomplicated postoperative course were analysed. Even with restrictive fluid management performed as part of the ERAS protocol, hypervolemia developed in 54 % of all patients on the first postoperative day. There were no cases of excessive peripheral or pulmonary oedema in cases with excessive fluid administration. Twenty-six percent of the patients had electrolyte imbalances, euvolaemia was seen in 22 %, and 85 % of these patients had hypokalemia. CONCLUSION: Postoperative registration of fluid charts is difficult, which results in incomplete charts. This has resulted in more attention being paid to recording the fluid balance at our institution. Concerning electrolyte disorders, we recommend prophylactic potassium administration. However, there is no reason to replace standard 0.9 % NaCl/glucose 5 % by Ringer's lactate, as the British guidelines advice.

Integrated histopathological and urinary metabonomic investigation of the pathogenesis of microcystin-LR toxicosis.

Patterns of change of endogenous metabolites may closely reflect systemic and organ-specific toxic changes. The authors examined the metabolic effects of the cyanobacterial (blue-green algal) toxin microcystin-LR by (1)H-nuclear magnetic resonance (NMR) analysis of urinary endogenous metabolites. Rats were treated with a single sublethal dose, either 20 or 80 µg/kg intraperitoneally, and sacrificed at 2 or 7 days post dosing. Changes in the high-dose, 2-day sacrifice group included centrilobular hepatic necrosis and congestion, accompanied in some animals by regeneration and neovascularization. By 7 days, animals had recovered, the necrotizing process had ended, and the centrilobular areas had been replaced by regenerative, usually hypertrophic hepatocytes. There was considerable interanimal variation in the histologic process and severity, which correlated with the changes in patterns of endogenous metabolites in the urine, thus providing additional validation of the biomarker and biochemical changes. Similarity of the shape of the metabolic trajectories suggests that the mechanisms of toxic effects and recovery are similar among the individual animals, albeit that the magnitude and timing are different for the individual animals. Initial decreases in urinary citrate, 2-oxoglutarate, succinate, and hippurate concentrations were accompanied by a temporary increase in betaine and taurine, then creatine from 24 to 48 hours. Further changes were an increase in guanidinoacetate, dimethylglycine, urocanic acid, and bile acids. As a tool, urine can be repeatedly and noninvasively sampled and metabonomics utilized to study the onset and recovery after toxicity, thus identifying time points of maximal effect. This can help to employ histopathological examination in a guided and effective fashion.

"Axillary recurrences after sentinel lymph node biopsy: a multicentre analysis and follow-up of sentinel lymph node negative breast cancer patients".

INTRODUCTION: The objective of this study was to conduct a multicentre data analysis to identify prognostic factors for developing an axillary recurrence (AR) after negative sentinel lymph node biopsy (SLNB) in a large cohort of breast cancer patients with long follow-up. PATIENTS AND METHODS: The prospective databases from different hospitals of clinically node negative breast cancer patients operated on between, 2000 and 2002 were analyzed. SLNB was performed and pathological analysis done by local pathologists according to national guidelines. Adjuvant treatment was given according to contemporary guidelines. Multivariate analysis was performed using all available variables, a p-value of <0,05 was considered to be significant. RESULTS: A total of 929 patients who did not undergo axillary lymph node dissection were identified. After a median follow up of 77 (range 1-106) months, fifteen patients developed an isolated AR (AR rate 1,6%). Multivariate analysis showed that young age (p = 0.007) and the absence of radiotherapy (p = 0.010) significantly increased the risk of developing an AR. Distant metastasis free survival (DMFS) was significantly worse for patients with an AR compared to all other breast cancer patients (p < 0,0001). CONCLUSION: Even after long-term follow up, the risk of developing an AR after a negative SLN in breast cancer is low. Young age and absence of radiation therapy are highly significant factors for developing an axillary recurrence. DMFS is worse for AR patients compared to patients initially diagnosed with N0 or N1 disease.

ARM: axillary reverse mapping - the need for selection of patients.

BACKGROUND: Axillary reverse mapping (ARM) is a technique that discerns axillary lymphatic drainage of the arm from the breast. This study was performed to evaluate both the feasibility of this technique and the proportion of metastatic involvement of ARM-nodes. PATIENTS AND METHODS: Patients with invasive breast cancer and an indication for axillary lymph node dissection (ALND) were enrolled in the study: patients with a tumor-positive sentinel lymph node (SLN(+)-group) and patients who had axillary metastases proven by preoperative cytology (CP-N(+)-group) were distinguished. ARM was performed in all patients by injecting blue dye. During surgery ARM-nodes were identified and removed first, followed by ALND. RESULTS: Between October 2009 and June 2011 93 patients underwent ARM. There were 43 patients in the SLN(+)-group and 50 patients in the CP-N(+)-group. No significant differences in visualization rate of ARM-nodes between the groups (86 vs 94% respectively, P = 0.196) were identified. In the SLN(+)-group none of the ARM-nodes contained metastases versus 11 patients (22%) in the CP-N(+)-group (P = 0.001). Patients receiving neoadjuvant systemic therapy had a significantly lower risk of additional axillary lymph node metastases (24.6 vs 44.4%, P = 0.046). DISCUSSION: The ARM procedure is technically feasible with a high visualization rate. The proportion of patients with metastases in the ARM-nodes was significantly higher in patients with proven axillary metastases than in patients with a positive SLN. Patients with SLN metastases appear to be good candidates for the ARM technique and possibly also patients with proven axillary metastases receiving neoadjuvant chemotherapy.

Modelling shellfish growth with dynamic energy budget models: an application for cockles and mussels in the Oosterschelde (southwest Netherlands).

Dynamic energy budget models for growth of individual cockles (Cerastoderma edule) and mussels (Mytilus edulis) are adjusted and calibrated to the Oosterschelde by formulating and parametrizing their functional responses using an extensive set of field observations. The resulting model predictions fit the observations satisfactorily. Results indicate that food quality and the importance of detritus as a food source are site-specific as well as species-specific. Despite these differences in their calibrated parameter values, both species show a very similar functional response. Compared with other systems, however, the functional responses of mussels in the present study are clearly higher than those of mussels in other systems. This may be explained by the absence of intra-specific competition in the measurement set-up that was used, and therefore supports the idea that the generally small functional response of M. edulis is caused by intra-specific competition.

The incidence and significance of micrometastases in lymph nodes of patients with ductal carcinoma in situ and T1a carcinoma of the breast.

AIM: To report the incidence and predictive value of positive axillary nodes in ductal carcinoma in situ (DCIS) and T1a carcinoma of the breast. METHODS: Cases from The Netherlands Cancer Institute were used to determine the incidence of lymph-node metastases. All consecutive patients with primary breast cancer that were treated between 1989 and 1998 and who had undergone axillary dissection were selected. Patients were identified with pure DCIS (n = 71), DCIS with small invasion (n = 12), invasive ductal/lobular carcinoma (IDC/ILC) < or =5 mm (n = 18) or tubular carcinoma < or =10 mm (n = 17). All archived lymph nodes of these patients were re-evaluated using immunohistochemistry (IHC). RESULTS: In DCIS the incidence increased from 1.4% with routine staining to 11% with IHC. For DCIS with small invasion it was 0 vs 27%, respectively. In IDC/ILC sized 2-5 mm the incidence rose from 6 to 12% and in tubular carcinoma < or =10 mm from 0 to 12%. All but one of the immunohistochemically detected metastases were isolated tumour cells (n = 9) or small (micro)metastases (n = 4). Maximally two nodes per patient were affected. None of the patients with positive lymph nodes died during follow-up (mean 102 months). CONCLUSIONS: Survival of our patients appeared not to be influenced by the finding of micrometastases in the lymph nodes by IHC. Immunohistochemistry of the sentinel node seems not contributive to further treatment in these patients.

[The para-esophageal hernia: a rare hiatal hernia requiring a specific approach]. / De para-oesofageale hernia: een zeldzame hiatushernia die een eigen aanpak vereist.

In three patients, a woman aged 87 years who presented with signs indicating a myocardial infarction, a man aged 31 suffering from postprandial epigastric pain that suddenly worsened, and a woman aged 60 years with longstanding postprandial pain and recent fatigue due to anaemia, a para-oesophageal hernia was diagnosed. Para-oesophageal herniation is an uncommon disorder accounting for approximately 5% of all hernias at the oesophageal hiatus. They are distinguished from the more common sliding hiatal hernia by a relative preservation of the intra-abdominal fixation of the gastro-oesophageal junction. These patients show that the clinical presentation of para-oesophageal rolling hernias is different from that of sliding hernias. Pathological reflux may occur; though symptoms associated with a relative obstruction of the stomach within the hernia sac, such as dysphagia, are more common. Rare non-specific symptoms such as anaemia and loss of weight are also seen. Adequate therapy differs from that of a sliding hernia and should be individualized: surgical correction is indicated in a healthy patient with a symptomatic para-oesophageal hernia, such as in the last patient. However, when the hernia is incidentally diagnosed or when comorbidity is present, such as in the first patient, a wait-and-see policy is recommended. Only in case of a threatening incarceration, such as in the second patient, is an emergency operation indicated.

BACE knockout mice are healthy despite lacking the primary beta-secretase activity in brain: implications for Alzheimer's disease therapeutics.

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by accumulation of amyloid plaques and neurofibrillary tangles in the brain. The major components of plaque, beta-amyloid peptides (Abetas), are produced from amyloid precursor protein (APP) by the activity of beta- and gamma-secretases. beta-secretase activity cleaves APP to define the N-terminus of the Abeta1-x peptides and, therefore, has been a long- sought therapeutic target for treatment of AD. The gene encoding a beta-secretase for beta-site APP cleaving enzyme (BACE) was identified recently. However, it was not known whether BACE was the primary beta-secretase in mammalian brain nor whether inhibition of beta-secretase might have effects in mammals that would preclude its utility as a therapeutic target. In the work described herein, we generated two lines of BACE knockout mice and characterized them for pathology, beta-secretase activity and Abeta production. These mice appeared to develop normally and showed no consistent phenotypic differences from their wild-type littermates, including overall normal tissue morphology and brain histochemistry, normal blood and urine chemistries, normal blood-cell composition, and no overt behavioral and neuromuscular effects. Brain and primary cortical cultures from BACE knockout mice showed no detectable beta-secretase activity, and primary cortical cultures from BACE knockout mice produced much less Abeta from APP. The findings that BACE is the primary beta-secretase activity in brain and that loss of beta-secretase activity produces no profound phenotypic defects with a concomitant reduction in beta-amyloid peptide clearly indicate that BACE is an excellent therapeutic target for treatment of AD.

Rapid and sensitive detection of all types of MLL gene translocations with a single FISH probe set.

The MLL gene on chromosome 11 band q23 is frequently involved in chromosome translocations in acute lymphoblastic leukemia and acute myeloid leukemia. The translocation results in the formation of a fusion gene on the derivative 11 chromosome consisting of the 5' part of the MLL gene and the 3' part of another gene; already more than 30 different partner chromosome regions have been described. MLL gene rearrangements are generally correlated with a poor prognosis. Therefore the presence of an 11q23 aberration has direct implications for treatment stratification, making early and rapid detection of utmost importance. In this study, we developed a FISH probe set for detection of MLL gene rearrangements according to strict design criteria. The cosmid probes are derived from the flanking regions of the MLL breakpoint region on chromosome 11 and when used in dual colored FISH experiments give rise to a split of the normally colocalizing (fused) signals in case of a translocation. This split signal was observed in seven out of 10 cases with an 11q23 translocation with various partner chromosomes. In the three other cases, a deletion of the 3' part of the MLL gene, downstream of the breakpoint region was also found. A low false positive value of only 1.7% was obtained for interphase cells in contrast to conventional dual colored FISH where the creation of a fusion signal has cut off values of at least 5-10%. A major advantage of our type of probe set is the application of a single FISH experiment to detect all types of MLL translocations. Moreover, since this cosmid probe set can be used for either interphase or metaphase studies, metaphases are no longer a prerequisite for detecting the presence of an 11q23 translocation. Nevertheless, metaphase FISH with the new probe set is helpful in determining the partner chromosome and therefore may lead to the identification of new partner genes.

Cytotoxicity of sulfonamide reactive metabolites: apoptosis and selective toxicity of CD8(+) cells by the hydroxylamine of sulfamethoxazole.

Treatment with sulfonamide antibiotics in HIV-infected patients is associated with a high incidence (> 40%) of adverse drug events, including severe hypersensitivity reactions. Sulfonamide reactive metabolites have been implicated in the pathogenesis of these adverse reactions. Sulfamethoxazole hydroxylamine (SMX-HA) induces lymphocyte toxicity and suppression of proliferation in vitro; the mechanism(s) of these immunomodulatory effects remain unknown. We investigated the cytotoxicity of SMX-HA via apoptosis on human peripheral blood mononuclear cells and purified cell subpopulations in vitro. CD19(+), CD4(+), and CD8(+) cells were isolated from human peripheral blood by positive selection of cell surface molecules by magnetic bead separation. SMX-HA induced significant CD8(+) cell death (67 +/- 7%) at 100 microM SMX-HA, with only minimal CD4(+) cell death (8 +/- 4%). No significant subpopulation toxicity was shown when incubated with parent drug (SMX). Flow cytometry measuring phosphatidylserine externalization 24 h after treatment with 100 microM and 400 microM SMX-HA revealed 14.1 +/- 0.7% and 25. 6 +/- 4.2% annexin-positive cells, respectively, compared to 3.7 +/- 1.2% in control PBMCs treated with 400 microM SMX. Internucleosomal DNA fragmentation was observed in quiescent and stimulated PBMCs 48 h after incubation with SMX-HA. Our data show that CD8(+) cells are highly susceptible to the toxic effects of SMX-HA through enhanced cell death by apoptosis.

Immortalized mouse brain endothelial cells are ultrastructurally similar to endothelial cells and respond to astrocyte-conditioned medium.

Studies of brain microvessel endothelial cell physiology and blood-brain barrier properties are often hampered by the requirement of repeatedly producing and characterizing primary endothelial cell cultures. The use of viral oncogenes to produce several immortalized brain microvessel cell lines has been reported. The resulting cell lines express many properties of the blood-brain barrier phenotype but do not completely mimic primary endothelial cells in culture. As immortalized brain microvessel endothelial cell lines have not yet been produced from mice, we transformed mouse brain endothelial cells with the adenovirus E1A gene using a retroviral vector (DOL). Eight of 11 clones produced exhibited an endothelial-like cobblestone morphology and were characterized as endothelial with a panel of antibodies, lectins, and ultrastructural criteria. These cells are endothelial in origin and share ultrastructural features with primary cultures of endothelial cells. Examination of freeze fracture and transmission electron micrographs show adherens junctions exist between the transformed cells, and culture in astrocyte-conditioned medium induces the formation of gap junctions. This is one indication that responses to astrocyte-derived factors are retained by the transformed cell lines.

Development of an interphase fluorescent in situ hybridization (FISH) test to detect t(8;21) in AML patients.

The translocation (8;21) is a chromosome abnormality associated with acute myeloid leukemia (AML). As a consequence of the translocation the AML1 (CBFA2) gene in the 21q22 region is fused to the ETO(CDR,MTG8) gene in the 8q22 region, resulting in one transcriptionally active gene on the 8q- derivative chromosome. In this report we demonstrate the use of a highly specific dual-colour FISH method for the detection of t(8;21) on interphase cells. Genomic probes able to detect the chimeric AML1/ETO gene on the 8q- derivative chromosome were assayed on both normal and leukemic bone marrow and peripheral blood samples. Cut-off values were established by independent analysis of 15 bone marrow specimens negative for the translocation. The cut-off value of positive nuclei was determined to be 2% and the cut-off value for both positive nuclei and nuclei of uncertain classification, 4%. Persistence of cells above these cut-off values was interpreted as persistence of the mutated clone. A total of 36 samples at different disease stages were tested. Interphase cytogenetics detected the translocation at the onset and relapse in the BM or the PB of 14 AML patients with t(8;21). The technique appears to be an alternative tool to both conventional cytogenetics and reverse transcription polymerase chain reaction (RT-PCR) for the monitoring of disease during patients' follow-up. By enabling the analysis of individual cells, interphase FISH is ideal for clonality studies both for clinical and experimental applications.