Mario Veitl

The new hematology analyzer Sysmex XE-2100: performance evaluation of a novel white blood cell differential technology.

CONTEXT The new hematology analyzer Sysmex XE-2100 (TOA Medical Electronics, Kobe, Japan) has a novel, combined, white blood cell differential technology and a special reagent system to enumerate nucleated red blood cells. DESIGN Performance evaluation of both technologies of the Sysmex XE-2100 according to the H20-A protocol of the National Committee for Clinical and Laboratory Standards and comparison of the results with those for the hematology analyzer Sysmex NE-8000 (TOA Medical Electronics). SPECIMENS Five hundred forty-four blood samples randomly chosen from various inpatient and outpatient departments of the Vienna University hospital. RESULTS Five-part white blood cell differential counts on the XE-2100 revealed excellent correlation with the manual reference method for neutrophils, lymphocytes, and eosinophils (r =.925,.922, and.877, respectively) and good correlation for monocytes and basophils (r =.756 and.763, respectively). The efficiency rates of flagging for the presence of >/=1% abnormal white blood cells were 83% (XE-2100) and 66% (NE-8000). The correlation of automated and microscopic nucleated red blood cell counts was excellent (r =.97). CONCLUSIONS From the present evaluation and our former experience with other types of Sysmex analyzers, we conclude that the new white blood cell differential technology of the XE-2100 represents a further development toward more efficient flagging of abnormal white blood cells.

Riboflavin Is a Determinant of Total Homocysteine Plasma Concentrations in End-Stage Renal Disease Patients

The effect of thiamine (vitamin B(1)) or riboflavin (vitamin B(2)) availability on fasting total homocysteine (tHcy) plasma levels in end-stage renal disease patients is unknown. A cross-sectional study was performed in a population of non-vitamin supplemented patients maintained on continuous ambulatory peritoneal dialysis. Red blood cell availability of thiamine (alpha-ETK) and of riboflavin (alpha-EGR), along with other predictors of tHcy plasma levels, was considered in the analysis. There was a linear association of alpha-EGR with tHcy plasma concentrations (P = 0.009), which was not observed for alpha-ETK. Among red blood cell vitamins, alpha-EGR was the only predictor of tHcy levels (P = 0.035), whereas alpha-ETK, red blood cell pyridoxal-5-phosphate supply (alpha-EGOT) and red blood cell folate levels had no effect. The risk for having a high tHcy plasma levels within the fourth quartile (plasma tHcy >38.3 micromol/L) was increased by an alpha-EGR > median (odds ratio, 4.706; 95% confidence interval, 1.124 to 19.704; P = 0.026). By way of contrast, alpha-ETK had no effect in these analyses. Independent predictors of tHcy plasma levels were serum albumin, alpha-EGR, red blood cell folate, and certain MTHFR genotypes. A logistic regression analysis showed that the MTHFR genotype is a predictor for having a tHcy plasma concentration within the fourth quartile. In summary, riboflavin availability, as measured by alpha-EGR, is a determinant of fasting tHcy plasma levels in peritoneal dialysis patients. This finding may have implications for tHcy lowering therapy in individuals with end-stage renal disease.

Survival improvement in patients with glioblastoma multiforme during the last 20 years in a single tertiary-care center

ZusammenfassungStudienzielZiel der retrospektiven Analyse war es, die Überlebensdauer und einen eventuellen Fortschritt von 357 konsekutiven Patienten mit Gliob lastoma multiforme (GBM) innerhalb von 3 Gruppen aus unterschiedlichen Diagnose-Zeiträumen (Gruppe A: 1982–1984, B: 1994/1995; C: 1996–1998), die während der letzten 20 Jahre an unserem tertiärem Zentrum behandelt wurden, zu untersuchen.Patienten und MethodenPatienten der Gruppe A (n=100) wurden zwischen 1982 und 1984 diagnostiziert und dienten als historische Kontrolle. Patienten der Gruppe B (n=93) wurden 1994/1995 und Patienten der Gruppe C (n=164) zwischen 1996 und 1998 diagnostiziert.Die Überlebens-Analyse wurde durchgeführt in Bezug auf die drei Patientengruppen (A versus B versus C), in Bezug auf die applizierten Therapiemodalitäten nach neurochirurgischer Intervention (keine spezifische Therapie versus Radiotherapie versus kombinierte Radio-/Chemotherapie), in Bezug auf die unterschiedlichen first-line Chemotherapien, in Bezug auf Alter, Geschlecht und Tumorlokalisation. Die non-parametrische Kaplan-Meier Methode wurde angewandt. Ein p-Wert <0,05 wurde als statistisch signifikant angesehen.Patienten der Gruppen A und B erhielten Radio- und/oder Chemotherapie in einem unterschiedlichen Ausmaß (Radiotherapie: Gruppe A: 22%, Gruppe B: 62%; Chemotherapie: Gruppe A: 6%, Gruppe B: 33%). Die Chemotherapie wurde in beiden Gruppen nach Abschluss der Radiotherapie appliziert. In Gruppe C erhielten 96% der Patienten eine kombinierte Radio-/Chemotherapie innerhalb von 3 Wochen nach der neurochriurgischen Intervention.ErgbnisseDas mediane Überleben betrug in Gruppe A 5,2 Monate, in Gruppe B 5, 1 Monate und in Gruppe C 14,5 Monate (p<0,0001). Länger als 18 Monate lebten 9% der Patienten in Gruppe A, 10% der Patienten in Gruppe B und 25% der Patienten in Gruppe C (p<0,05).SchlussfolgerungDie Überlebenszeitverbesserung in Gruppe C ist auf die frühzeitige und kombineierte Applikation von Radio-/Chemotherapie zurückzuführen. Die Therapie wurde ambulant durchgeführt; dies wurde durch ein interdisziplinäres neuro-onkologisches Team ermöglicht. Die Nebenwirkungen waren mild und die Akzeptanz bei den Patienten hervorragend.SummaryMethodologyThe survival of 357 consecutive patients with newly diagnosed glioblastoma multiforme (GBM) in three treatment groups reflecting different time-periods of diagnosis (A: 1982–1984; B: 1994/1995; C: 1996–1998) was analysed to assess the impact and the potential improvement of changing treatment strategies in our tertiary-care center.Patients and methodsGroup A (n=100) included all consecutive patients diagnosed from 1982 to 1984 and served as the historical control. Group B (n=93) included all consecutive patients diagnosed in 1994/1995 and group C (n=164) those diagnosed from 1996 to 1998. Survival in the three treatment groups (A vs. B vs. C) was analysed according to treatment given after neurosurgical intervention (i.e. no specific therapy versus radiotherapy versus combined radio-/chemotherapy), and according to first-line chemotherapy, age (<40, 40–60, ≥60), sex, and tumor location (hemispheric versus bilateral or multifocal tumors, and tumors involving eloquent brain areas). Survival was analysed using Kaplan-Meier’s non-parametric method. A p-value <0.05 was considered statistically significant.ResultsPatients in groups A and B received radio-and/or chemotherapy to a varying extent (radiotherapy: group A: 22%, group B: 62%; chemotherapy: group A: 6%, group B: 33%). Chemotherapy was administered after termination of radiotherapy in both groups. In group C, 96% of patients received combined radio-/chemotherapy which was administered concomitantly and started within three weeks after surgery.Median survival was 5.2 months in group A, 5.1 months in group B and 14.5 months in C (p<0.0001). Nine patients in group A (9%), 9 in group B (10%) and 40 in group C (25%) survived more than 18 months (p<0.05).ConclusionsSurvival improvement in group C might be attributable to the early start of combined radio-/chemotherapy. Therapy was administered on a complete outpatient basis, enabled by a dedicated interdisciplinary neuro-oncologic team caring for group C. Toxicity was mild and patients’ acceptance excellent.

Cholinergic markers in ALS spinal cord

We analyzed binding sites for quinuclidinyl benzilate (QNB) and hemicholinium-3 (HC-3) by quantitative slice autoradiography and the activities of choline acetyltransferase (ChAT) and acetylcholinesterase (AChE) in spinal cord of 5-7 patients with amyotrophic lateral sclerosis (ALS). In the ventral horn, QNB binding sites were markedly reduced (38% of controls; P less than 0.001), whereas HC-3 binding sites were only moderately affected (76%, P less than 0.01). Losses in cholinergic marker enzymes were inconsistent. The loss of muscarinic binding sites in the ventral horn was the most reliable cholinergic disease marker in ALS.

Role of immunological lymphocyte subset typing as a screening method for lymphoid malignancies in daily routine practice

BACKGROUND The major diagnostic role of peripheral lymphocyte subset typing is to distinguish between malignant and reactive conditions. METHODS The present study evaluates the screening efficacy of flow cytometric lymphocyte subset typing for the presence of a lymphoid malignancy. Four hundred samples were analyzed with a combination of anti-T-, B-, and natural killer (NK)-cell monoclonal antibodies. RESULTS Two hundred and twenty (55%) samples showed a normal distribution of lymphocyte subsets, 73 (18%) samples exhibited unspecific alterations of lymphocyte subsets, 19 (5%) samples exhibited a reactive phenotype typical of Epstein-Barr virus/cytomegalovirus (EBV/CMV) infection, and 88 (22%) samples expressed a phenotype suggestive of lymphoma. The most predictive independent factor of a lymphoma-specific phenotype was the absolute lymphocyte count (P = 0.0001, odds ratio 73.225). Seventy-eight percent of samples containing >/=4 x 10(9)/l lymphocytes and 2% of samples with lymphocyte counts <4 x 10(9)/l exhibited a lymphoma-specific phenotype. The specificity of the referring clinical comment was the second best predictor of a lymphoma-specific typing outcome (P = 0.0001, odds ratio 19.589). The independent predictive values of lymphocyte morphology and of relative lymphocyte counts were of borderline significance. CONCLUSIONS The use of flow cytometric lymphocyte subset typing as a diagnostic screening method for lymphoma should be restricted to cases of unexplained elevation of absolute lymphocyte counts with or without morphological atypias and to cases with definite clinical symptoms of lymphoma.

AUTONOMOUS AGENTS IN USER INTERFACES

In this paper we present novel concepts for user interfaces based on agents actively exploring their environment, including the users behavior. These autonomous agents are active entities in a hypermedia artwork on the development and artistic challenge of three-dimensional sculpturing on video screens and with laser installations. Such an approach challenges current paradigms of user interfaces in a fundamental way. Each individual, users and agents alike, is forced to construct their own concepts and strategies to operate successfully, based on their experiences. The strategies of the agent cannot be conveyed explicitly. Instead, they emerge from concepts of the domain, concepts of the users, the agents own drives, and the interactions between users and the agent; all together they form the main source for the generation of new concepts and strategies. The history of behavior-based robotics provides us with similar evidence that active exploration in particular as opposed to mere deliberation constitu...

UNIFIED SIMULATION MODEL OF MEDICAL LABORATORY ORGANIZATION

This article shows how discrete simulation can be used to model the working flow in a medical laboratory. Such models give a deeper understanding of the system and can be used to predict changes of behavior caused by disturbances such as breakdowns of analyzers or organizational changes. Our models are based on data collected and evaluated in the Clinical Institute for Medical and Chemical Laboratory Diagnostics of the University of Vienna. At first different analyzers and working processes were analyzed and a unified model was defined, which contains adjustable parameters for modeling individual workplaces and analyzers. These individually configured representations of the unified model were subsequently connected and arranged into a model of laboratory workflow. The simulation experiments show some scenarios of organizational approaches and their system behaviors in the case of disturbances. Furthermore, we discuss cost savings in the decision-making process due to inexpensive computer-based evaluation ...