Predicting response to neoadjuvant chemotherapy with liquid biopsies and multiparametric MRI in patients with breast cancer.

Accurate prediction of response to neoadjuvant chemotherapy (NAC) can help tailor treatment to individual patients' needs. Little is known about the combination of liquid biopsies and computer extracted features from multiparametric magnetic resonance imaging (MRI) for the prediction of NAC response in breast cancer. Here, we report on a prospective study with the aim to explore the predictive potential of this combination in adjunct to standard clinical and pathological information before, during and after NAC. The study was performed in four Dutch hospitals. Patients without metastases treated with NAC underwent 3 T multiparametric MRI scans before, during and after NAC. Liquid biopsies were obtained before every chemotherapy cycle and before surgery. Prediction models were developed using penalized linear regression to forecast residual cancer burden after NAC and evaluated for pathologic complete response (pCR) using leave-one-out-cross-validation (LOOCV). Sixty-one patients were included. Twenty-three patients (38%) achieved pCR. Most prediction models yielded the highest estimated LOOCV area under the curve (AUC) at the post-treatment timepoint. A clinical-only model including tumor grade, nodal status and receptor subtype yielded an estimated LOOCV AUC for pCR of 0.76, which increased to 0.82 by incorporating post-treatment radiological MRI assessment (i.e., the "clinical-radiological" model). The estimated LOOCV AUC was 0.84 after incorporation of computer-extracted MRI features, and 0.85 when liquid biopsy information was added instead of the radiological MRI assessment. Adding liquid biopsy information to the clinical-radiological resulted in an estimated LOOCV AUC of 0.86. In conclusion, inclusion of liquid biopsy-derived markers in clinical-radiological prediction models may have potential to improve prediction of pCR after NAC in breast cancer.

Personalized neck irradiation guided by sentinel lymph node biopsy in patients with squamous cell carcinoma of the oropharynx, larynx or hypopharynx with a clinically negative neck: (Chemo)radiotherapy to the PRIMary tumor only. Protocol of the PRIMO study.

Background: Elective neck irradiation (ENI) is performed in head and neck cancer patients treated with definitive (chemo)radiotherapy. The aim is to eradicate nodal metastases that are not detectable by pretreatment imaging techniques. It is conceivable that personalized neck irradiation can be performed guided by the results of sentinel lymph node biopsy (SLNB). It is expected that ENI can be omitted to one or both sides of the neck in 9 out of 10 patients, resulting in less radiation side effects with better quality of life. Methods/design: This is a multicenter randomized controlled trial aiming to compare safety and efficacy of treatment with SLNB guided neck irradiation versus standard bilateral ENI in 242 patients with cN0 squamous cell carcinoma of the oropharynx, larynx or hypopharynx for whom bilateral ENI is indicated. Patients randomized to the experimental-arm will undergo SLNB. Based on the histopathologic status of the SLNs, patients will receive no ENI (if all SLNs are negative), unilateral neck irradiation only (if a SLN is positive at one side of the neck) or bilateral neck irradiation (if SLNs are positive at both sides of the neck). Patients randomized to the control arm will not undergo SLNB but will receive standard bilateral ENI. The primary safety endpoint is the number of patients with recurrence in regional lymph nodes within 2 years after treatment. The primary efficacy endpoint is patient reported xerostomia-related quality of life at 6 months after treatment. Discussion: If this trial demonstrates that the experimental treatment is non-inferior to the standard treatment in terms of regional recurrence and is superior in terms of xerostomia-related quality of life, this will become the new standard of care.

Expansion of off-site percutaneous coronary intervention centres significantly reduces ambulance driving time to primary PCI in the Netherlands.

INTRODUCTION: In patients with ST-elevation myocardial infarction (STEMI), percutaneous coronary intervention (PCI)-mediated reperfusion is preferred over pharmacoinvasive reperfusion with fibrinolysis if transfer to a PCI centre can be ensured in ≤120 min. We evaluated the ambulance driving time to primary PCI centres in the Netherlands and assessed to what extent ambulance driving times were impacted by the expansion of off-site PCI centres. METHODS AND RESULTS: We calculated the driving routes from every Dutch postal code to the nearest PCI centre with (on-site) or without (off-site) surgical back-up. We used data from ambulance records to estimate the ambulance driving time on each route. There were 16 on-site and 14 off-site PCI centres. The median (interquartile range) time to on-site PCI centres was 18.8 min (12.2-26.3) compared with 14.9 min (8.9-20.9) to any PCI centre (p < 0.001). In postal code areas that were impacted by the initiation of off-site PCI, the median driving time decreased from 25.4 (18.2-33.1) to 14.7 min (8.9-20.9) (p < 0.001). Ambulance driving times of >120 min were only seen in non-mainland areas. CONCLUSION: Based on a computational model, timely ambulance transfer to a PCI centre within 120 min is available to almost all STEMI patients in the Netherlands. Expansion of off-site PCI has significantly reduced the driving time to PCI centres.

Reductive catalytic fractionation of pine wood: elucidating and quantifying the molecular structures in the lignin oil.

In-depth structural analysis of biorefined lignin is imperative to understand its physicochemical properties, essential for its efficient valorization to renewable materials and chemicals. Up to now, research on Reductive Catalytic Fractionation (RCF) of lignocellulose biomass, an emerging biorefinery technology, has strongly focused on the formation, separation and quantitative analysis of the abundant lignin-derived phenolic monomers. However, detailed structural information on the linkages in RCF lignin oligomers, constituting up to 50 wt% of RCF lignin, and their quantification, is currently lacking. This study discloses new detailed insights into the pine wood RCF lignin oil's molecular structure through the combination of fractionation and systematic analysis, resulting in the first assignment of the major RCF-derived structural units in the 1H-13C HSQC NMR spectrum of the RCF oligomers. Specifically, ß-5 γ-OH, ß-5 ethyl, ß-1 γ-OH, ß-1 ethyl, ß-ß 2x γ-OH, ß-ß THF, and 5-5 inter-unit linkages were assigned unambiguously, resulting in the quantification of over 80% of the lignin inter-unit linkages and end-units. Detailed inspection of the native lignin inter-unit linkages and their conversion reveals the occurring hydrogenolysis chemistry and the unambiguous proof of absence of lignin fragment condensation during proper RCF processing. Overall, the study offers an advanced analytical toolbox for future RCF lignin conversion and lignin structural analysis research, and valuable insights for lignin oil valorization purposes.

Oral & Maxillofacial surgery is ready for patient-centred eHealth interventions - the outcomes of a scoping review.

Within the field of oral and maxillofacial (OMF) surgery, eHealth is expected to be a tool to improve quality of care. The aim of this study is to map the research of patient-centred eHealth interventions within OMF surgery by means of a scoping review. After a systematic literature search, relevant studies on patient-centred eHealth interventions for OMF-surgery patients were selected. The interventions were mapped based on their key components, target population and outcome measures. To gain insight in the research phase of evaluation, the framework of the Medical Research Council (MRC) was used. Forty-one papers were included, comprising 34 unique interventions. Nineteen interventions were designed for head and neck cancer patients, 11 interventions concernd video-teleconsultation. According to the MRC framework, 26 papers fitted into the feasibility and piloting phase of research, 8 into the evaluation phase, 7 were in the development phase. No implementation studies were found. This scoping review can be a starting point for those who are interested in applying and evaluating eHealth in their practice. Since many feasibility and pilot studies were found on similar interventions, a more extensive collaboration with and connecting to each other is recommended to catalyze the implementation of eHealth in daily practice. Profound involvement of patients in developing and evaluating eHealth interventions is essential to achieve true patient-centred OMF surgery.

Catalytic Strategies Towards Lignin-Derived Chemicals.

Lignin valorization represents a crucial, yet underexploited component in current lignocellulosic biorefineries. An alluring opportunity is the selective depolymerization of lignin towards chemicals. Although challenged by lignin's recalcitrant nature, several successful (catalytic) strategies have emerged. This review provides an overview of different approaches to cope with detrimental lignin structural alterations at an early stage of the biorefinery process, thus enabling effective routes towards lignin-derived chemicals. A first general strategy is to isolate lignin with a better preserved native-like structure and therefore an increased amenability towards depolymerization in a subsequent step. Both mild process conditions as well as active stabilization methods will be discussed. An alternative is the simultaneous depolymerization-stabilization of native lignin towards stable lignin monomers. This approach requires a fast and efficient stabilization of reactive lignin intermediates in order to minimize lignin repolymerization and maximize the envisioned production of chemicals. Finally, the obtained lignin-derived compounds can serve as a platform towards a broad range of bio-based products. Their implementation will improve the sustainability of the chemical industry, but equally important will generate opportunities towards product innovations based on unique biobased chemical structures.

Chemicals from lignin: an interplay of lignocellulose fractionation, depolymerisation, and upgrading.

In pursuit of more sustainable and competitive biorefineries, the effective valorisation of lignin is key. An alluring opportunity is the exploitation of lignin as a resource for chemicals. Three technological biorefinery aspects will determine the realisation of a successful lignin-to-chemicals valorisation chain, namely (i) lignocellulose fractionation, (ii) lignin depolymerisation, and (iii) upgrading towards targeted chemicals. This review provides a summary and perspective of the extensive research that has been devoted to each of these three interconnected biorefinery aspects, ranging from industrially well-established techniques to the latest cutting edge innovations. To navigate the reader through the overwhelming collection of literature on each topic, distinct strategies/topics were delineated and summarised in comprehensive overview figures. Upon closer inspection, conceptual principles arise that rationalise the success of certain methodologies, and more importantly, can guide future research to further expand the portfolio of promising technologies. When targeting chemicals, a key objective during the fractionation and depolymerisation stage is to minimise lignin condensation (i.e. formation of resistive carbon-carbon linkages). During fractionation, this can be achieved by either (i) preserving the (native) lignin structure or (ii) by tolerating depolymerisation of the lignin polymer but preventing condensation through chemical quenching or physical removal of reactive intermediates. The latter strategy is also commonly applied in the lignin depolymerisation stage, while an alternative approach is to augment the relative rate of depolymerisation vs. condensation by enhancing the reactivity of the lignin structure towards depolymerisation. Finally, because depolymerised lignins often consist of a complex mixture of various compounds, upgrading of the raw product mixture through convergent transformations embodies a promising approach to decrease the complexity. This particular upgrading approach is termed funneling, and includes both chemocatalytic and biological strategies.

[Learning to see things from a different perspective: interns and residents collaborate with artists to become better doctors]. / Anders leren kijken en de ander leren zien.

In 2016 and 2017, we started an innovative learning track in the Radboudumc that combines arts and medical education, and appraised the learning processes involved. The voluntary track was followed by 32 and 30 participants respectively, mostly interns and a few residents. The initiative built upon the ideas of several American educational developments which incorporated museum visits. We extended the format by having participants join artists in their studios, to allow students to have an immersive experience of a different discipline, rather than only observing its end products. The track did not have specific learning objectives. However, participants were encouraged to set personal goals and to reflect on what they learned in terms of observation skills, creative thinking, personalized health care, and frame reflection. Here we report the rationale of the track, and illustrate preliminary conclusions with participants' quotes.

Patients and professionals have different views on online patient information about cleft lip and palate (CL/P).

Parents of children with a cleft lip and/or palate (CL/P) and patients with CL/P actively search for online information about CL/P. The quality of this information has not been sufficiently evaluated. The aim of this study was to define quality criteria for online information about CL/P and assess the quality of frequently accessed websites. Patients, parents, and professionals were equally involved in all stages of this study. A literature review was performed to obtain known quality criteria for online information. These criteria were prioritized by patients, parents, and professionals. The most important criteria were used to rate the quality of four websites on CL/P. Forty-two quality items were extracted from the literature. Patients, parents, and professionals agreed on the importance of 16 of these items. New groups of patients, parents, and professionals assessed four websites on CL/P. Although the groups were like-minded in their overall assessment of the quality of the websites, distinct differences emerged between the groups in relation to certain items. This study shows the importance of patient participation in healthcare research, as well as a feasible approach to do so. Involving patients in composing online health information will set different priorities, which is necessary in establishing high quality information.

Tuning the lignin oil OH-content with Ru and Pd catalysts during lignin hydrogenolysis on birch wood.

Liquid reductive processing of birch wood in the presence of commercial Ru/C or Pd/C catalysts yields about 50% of a select set of phenolic monomers and a variety of phenolic di- and oligomers, next to a solid carbohydrate pulp. Changing the catalyst from Ru/C to Pd/C drastically increases the OH-content of the lignin-derived products, in particular for the phenolic monomers.

Evaluation of strained alkynes for Cu-free click reaction in live mice.

INTRODUCTION: We report on our evaluation of the strain-promoted cyclooctyne-azide cycloaddition reaction for use in tumor pretargeting, comprising a side-by-side comparison of probes 1-3 bearing three distinct cyclooctyne moieties based respectively on the 1st and 2nd generation difluorinated cyclooctyne and the 1st generation dibenzocyclooctyne. METHODS: The probes were synthesized and labeled with (177)Lu with high yields. The probe stability and reactivity towards azides were evaluated in PBS and mouse serum, and their blood clearance, biodistribution and in vivo reactivity were evaluated in tumor-free mice. RESULTS: In serum the three probes exhibited sufficient stability for a pretargeting application with half-lives of 12-19h. In PBS, probes 2 and 3 were more reactive towards azido-conjugated Rituximab (Rtx-N3) than 1, but in contrast to 1, their reactivity decreased in mouse serum and mouse serum albumin solutions, as a result of covalent and non-covalent interactions with albumin. Biodistribution data confirmed the interactions with serum proteins in circulation: (177)Lu-1 showed a fast elimination from blood (t1/2,ß = 0.31h), while (177)Lu-2 and (177)Lu-3 were retained in blood for longer periods of time (t1/2,ß = 1.08 and 3.58h, respectively). Dual isotope biodistribution experiments assessing the reaction between (125)I-Rtx-N3 and (177)Lu-1-3 in circulation in mice showed a very limited retention of 2 and 3 in blood rich organs, indicating a minimal reactivity, while no such retention was observed for 1. CONCLUSION: The low reactivity of the studied cyclooctynes, and their serum interactions preclude their use at the low in vivo concentrations typical for pretargeting applications.

Prevention of thrombosis after microvascular tissue transfer in the head and neck. A review of the literature and the state of affairs in Dutch Head and Neck Cancer Centers.

Free vascularized graft or free-flap reconstruction is frequently used in the reconstruction of defects in head and neck oncology patients. A common complication in free-flap surgery is thrombosis. Thrombosis occurs in 8-14% of cases and often leads to flap failure. A review of the literature on this subject was carried out and Dutch head and neck cancer centres were asked to share their guidelines concerning the prevention of thrombosis after free vascularized graft surgery. No consensus in the literature was found on how thrombosis could best be prevented. The Dutch Head and Neck Cancer Centers use routine deep venous thrombosis prophylaxis to prevent thrombosis in the anastomosis. It was also concluded that non-pharmacologic measures for preventing thrombosis, such as meticulous microvascular surgery and smoking cessation prior to the operation, are thought to play an important role in the prevention of thrombosis in microvascular free-flap reconstructions. It has not been determined which pre- and postoperative pharmacologic measure can prevent thrombosis most effectively. A pharmacologic regimen to prevent thrombosis that is customized to the patient is suggested. This should be based on an individual risk profile for the development of thrombosis.

Aberrant methylation of the Adenomatous Polyposis Coli (APC) gene promoter is associated with the inflammatory breast cancer phenotype.

Aberrant methylation of the adenomatous polyposis coli (APC) gene promoter occurs in about 40% of breast tumours and has been correlated with reduced APC protein levels. To what extent epigenetic alterations of the APC gene may differ according to specific breast cancer phenotypes, remains to be elucidated. Our aim was to explore the role of APC methylation in the inflammatory breast cancer (IBC) phenotype. The status of APC gene promoter hypermethylation was investigated in DNA from normal breast tissues, IBC and non-IBC by both conventional and real-time quantitative methylation-specific PCR (MSP). APC methylation levels were compared with APC mRNA and protein levels. Hypermethylation of the APC gene promoter was present in 71% of IBC samples (n=21) and 43% of non-IBC samples (n=30) by conventional MSP (P=0.047). The APC gene also showed an increased frequency of high methylation levels in IBC (in 74% of cases, n=19) vs non-IBC (in 46% of cases, n=35) using a qMSP assay (P=0.048). We observed no significant association between APC methylation levels by qMSP and APC mRNA or protein expression levels. In conclusion, for the first time, we report the association of aberrant methylation of the APC gene promoter with the IBC phenotype, which might be of biological and clinical importance.

[Mirtazapine-induced dystonia in a patient with Alzheimer's disease]. / Acute dystonie door mirtazapine bij een patiënte met de ziekte van Alzheimer.

A 79-year old female patient with Alzheimer's disease developed acute dystonia twelve hours after taking a single dose of mirtazapine 30 mg. Forty-five hours later the patient's dystonia began to subside and after sixty hours it had disappeared completely. This side-effect of mirtazapine is hardly mentioned in the literature. So far, little is known about the pathophysiology of acute dystonia and the possible role of mirtazapine. Some hypotheses and recommendations are proposed.

Phase I clinical and pharmacokinetic studies of the taxoid derivative RPR 109881A administered as a 1-hour or a 3-hour infusion in patients with advanced solid tumors.

PURPOSE: To define the maximum tolerated dose (MTD), the recommended phase II dose, the optimal infusion duration and pharmacokinetics of the semisynthetic taxoid derivative RPR 109881A, given as a 1-h or 3-h infusion every 3 weeks. PATIENTS AND METHODS: RPR109881A was administered as a 1-h i.v. infusion to 34 patients (study 1) with oral steroids as pre-medication. In a subsequent study, 29 patients were treated at the recommended dose or at the dose immediately below (study 2); the first 14 patients received RPR 109881A as a 3-h infusion, while the subsequent 15 were randomized to receive the drug as a 1-h or 3-h infusion. The pharmacokinetics of RPR109881A was studied in plasma and urine and for selected patients in some biological fluids (cerebrospinal fluid, pleural effusion, ascitis). RESULTS: In study 1, the dose was escalated from 15 to 105 mg/m(2), at which dose two of five patients presented dose-limiting toxicities with febrile neutropenia (FN) after the first cycle, thus defining the MTD. The dose of 90 mg/m(2), at which grade 3/4 neutropenia was almost universal with FN in 18%, was recommended for phase II. At 90 mg/m(2) the incidence of diarrhea, fatigue and alopecia were 59, 29 and 70%, respectively. The results of study 2 were comparable to those of study 1, thus recommending the 1-h infusion duration for phase II evaluation. RPR 109881A exhibited a high total body clearance, a large distribution volume and long terminal half-life of 20 h. RPR 109881A was detected in cerebrospinal fluid shortly after the end of 1-h infusion. Three objective responses were observed in non-small-cell lung cancer (NSCLC) patients, including a patient with brain metastases. CONCLUSIONS: The antitumor activity in NSCLC, the reproducible profile of toxicity and above all the ability to cross the blood-brain barrier make RPR 109881A worthy of further disease-oriented clinical development.

Clinical and pharmacological phase I study with accelerated titration design of a daily times five schedule of BBR3464, a novel cationic triplatinum complex.

OBJECTIVES: To define the maximum tolerated dose (MTD), the toxicity and pharmacokinetic profile of BBR3464, a novel triplatinum complex. PATIENTS AND METHODS: Fourteen patients with advanced solid tumors not responsive to previous antitumor treatments received BBR 3464 on a daily x 5 schedule every twenty-eighth day. The drug was given as a one-hour infusion with pre-and post-treatment hydration (500 ml in one hour) and no antiemetic prophylaxis. The starting dose was 0.03 mg/m2/day. A modified accelerated titration escalation design was used. Total and free platinum (Pt) concentrations in plasma and urine were assessed by ICP-MS on days 1 and 5 of the first cycle. RESULTS: Dose was escalated four times up to 0.17 mg/m2/day. Short-lasting neutropenia and diarrhea of late onset were dose-limiting and defined the MTD at 0.12 mg/m2. Nausea and vomiting were rare, neither neuro- nor renal toxic effects were observed. BBR3464 showed a rapid distribution phase of 1 hour and a terminal half-life of several days. At 0.17 mg/m2 plasma Cmax and AUC on day 5 were higher than on day 1, indicating drug accumulation. Approximately 10% of the equivalent dose of BBR3464 (2.2%-13.4%) was recovered in a 24-hour urine collection. CONCLUSIONS: The higher than expected incidence of neutropenia and GI toxicity might be related to the prolonged half-life and accumulation of total and free Pt after daily administrations. Lack of nephrotoxicity and the low urinary excretion support the use of the drug without hydration. The single intermittent schedule has been selected for clinical development.

Intraperitoneal hypercoagulation and hypofibrinolysis is present in childhood peritonitis.

An increased rate of obstruction of peritoneal dialysis catheters is observed during peritonitis. Hypercoagulation and hypofibrinolysis may explain this increased occurrence. We studied plasminogen activator inhibitor type 1 antigen (PAI-1), tissue-type plasminogen activator antigen (t-PA), D-dimer (DD), plasmin-alpha2-antiplasmin complexes (PAP), and thrombin-antithrombin III complexes (TAT) in 7 children with peritonitis (group A) and 12 children during stable peritoneal dialysis (group B). Albumin, beta2-microglobulin, IgG, and alpha2-macroglobulin were measured for baseline transperitoneal protein transport. After a dwell of 6 h with 1.36% Dianeal, dialysate and serum samples were collected. Dialysate to plasma ratios of all proteins were calculated. During peritonitis (group A) TAT was higher: 34.7 versus 22.0 (P=0.01). PAI-1 was increased in group A: 76.5 versus 22.9 (P=0.004). PAP was decreased during peritonitis (group A): 24.9 versus 39.3 (P=0.01). In group A, DD were decreased. 10.8 versus 26.7 (P=0.002). t-PA was similar in both groups (23.7 in group A vs. 27.7 in group B; P=0.26). In both groups TAT, PAI-1, t-PA, PAP, and DD were significantly higher than in baseline transperitoneal transport, suggesting intraperitoneal production. Hypercoagulability and hypofibrinolysis were present during peritonitis compared with the control situation.

Reproducibility of detection of tyrosinase and MART-1 transcripts in the peripheral blood of melanoma patients: a quality control study using real-time quantitative RT-PCR.

In recent years, large discrepancies were described in the success rate of the tyrosinase reverse transcription polymerase chain reaction (RT-PCR) for detecting melanoma cells in the peripheral blood of melanoma patients. We present a quality control study in which we analysed the reproducibility of detection of tyrosinase and MART-1 transcripts in 106 blood samples from 68 melanoma patients (mainly stages III and IV). With this study, we aimed to improve insight in the reproducibility of a RT-PCR for the detection of (minimal) amounts of circulating melanoma cells. We performed two reverse transcriptions on each mRNA sample and performed tyrosinase and MART-1 nested PCRs in duplicate per cDNA sample. Thus, four tyrosinase and four MART-1 measurements were performed per blood sample. In our study, the majority of blood samples was negative for tyrosinase (80%) or MART-1 (66%). Only four samples were positive in all four determinations for tyrosinase and seven for MART-1. Variable results (1-3 times positive results) were obtained for tyrosinase and MART-1 in 16% and 27% respectively. MART-1 PCR had a better performance than tyrosinase PCR. Sensitivity increased when both markers were used. We reasoned that the low number of melanoma marker PCR-positive blood samples can be explained by differences in mRNA quality. By using real-time quantitative PCR, we found that this was not the case: amplification of porphobilinogen deaminase (PBGD), a low copy household gene, was not different in blood samples in which a melanoma marker was not detected from groups in which this marker was detected more or less consistently (1-4 times). When applying real-time quantitative PCR for tyrosinase and MART-1, we found that a low amount of SK-MEL-28 cell equivalents was present in the blood of melanoma patients, with a higher number of equivalents in the group with a consistently positive result. We conclude that low reproducibility of a repeated assay for the detection of circulating melanoma cells is not caused by differences in mRNA quality between the samples, but due to low numbers of amplifiable target mRNA molecules in the mRNA sample. Use of more than one marker and repetition of the assay will increase the probability of finding positive PCR results.

Intrapatient comparison of an intermittent and a continuous flow cell separator for the collection of progenitor and stem cells from the blood.

BACKGROUND AND OBJECTIVES: Continuous-flow and intermittent-flow blood cell separators (CFCS and IFCS) are both used to collect stem cells from the blood to rescue patients undergoing myeloablative treatment for cancer. MATERIALS AND METHODS: We designed a study to compare the collection efficiency of the two systems. The continuous-flow Cobe Spectra and the intermittent-flow Haemonetics MCS-3P were used to collect cells on consecutive days from 9 patients mobilised with G-CSF with or without chemotherapy. Blood obtained before leukapheresis and the leukapheresis product were analysed for their content of red and white cells, platelets, CD34-positive cells, GM-CFC, CFC-E, and BFU-E. An extraction ratio was calculated. RESULTS: We found that the CFCS extracted about 4 times more mononuclear cells per unit time, 3 times more CD34-positive, and 4 times more clonogenic cells than the IFCS. The subject acceptability of the two systems was similar. CONCLUSION: The CFCS is a more efficient system for stem cell collection. IFCS requires a longer harvesting time for the same result.

Distribution of mobilized progenitor cells in the buffy coat of the haemonetics MCS3p cell separator: a study to optimize the collection of progenitors by leukapheresis.

Hematopoietic progenitor and stem cells for transplantation can be mobilized into the circulation and collected by leukapheresis. In this procedure, the leukocytes are distributed in the buffy coat along a density gradient, and the composition of the final product depends on which layer was collected. For the Haemonetics MCS3p Cell Separator, the manufacturer recommended starting the progenitor cell collection at a light transmission of 30%-40% (compared with plasma) and continue it for 40-50 ml. To optimize the use of this machine, the buffy coat it produces was studied in 12 patients by collecting it in fractions of increasing specific weight. Each fraction was analyzed by morphology, immunocytometry, and cell culture. We found that the buffy coat uniformly contains 8 times more leukocytes than blood, but the proportion of each white cell type varies along a gradient. The lymphocyte-predominant lighter layers are richer in CD34+ cells when compared with the granulocyte-predominant denser layers (6-14 times versus 2-4 times more than blood). The majority of CD34+ cells are found at a light transmission of 10%-70% (hematocrit 6-9). We conclude that cells for transplantation should be collected in a lighter fraction of the buffy coat than originally suggested by the manufacturer.