Pre-treatment expectations of patients with spinal metastases: what do we know and what can we learn from other disciplines? A systematic review of qualitative studies.

BACKGROUND: Little is known about treatment expectations of patients with spinal metastases undergoing radiotherapy and/or surgery. Assuming that patients with spinal metastases share characteristics with patients who had spinal surgery for non-cancer related conditions and with advanced cancer patients, we performed a systematic review to summarize the literature on patient expectations regarding treatment outcomes of spinal surgery and advanced cancer care. METHODS: A comprehensive search was performed in MEDLINE, EMBASE and PsycINFO for studies between 2000 and sep-2019. Studies including adult patients (> 18 years), undergoing spinal surgery or receiving advanced cancer care, investigating patients' pre-treatment expectations regarding treatment outcomes were included. Two independent reviewers screened titles, abstracts and full-texts, extracted data and assessed methodological quality. RESULTS: The search identified 7343 articles, of which 92 were selected for full-text review. For this review, 31 articles were included. Patients undergoing spinal surgery had overly optimistic expectations regarding pain and symptom relief, they underestimated the probability of functional disability, and overestimated the probability of (complete) recovery and return to work. Studies highlighted that patients feel not adequately prepared for surgery in terms of post-treatment expectations. Similarly, advanced cancer patients receiving palliative treatment often had overly optimistic expectations regarding their survival probability and cure rates. CONCLUSIONS: Patients tend to have overly optimistic expectations regarding pain and symptom relief, recovery and prognosis following spinal surgery or advanced cancer care. Pretreatment consultation about the expected pain and symptom relief, recovery and prognosis may improve understanding of prognosis, and promote and manage expectations, which, in turn, may lead to better perceived outcomes. TRIAL REGISTRATION: PROSPERO registration number: CRD42020145151 .

Managing unsolicited findings in genomics: A qualitative interview study with cancer patients.

OBJECTIVE: Next-generation sequencing (NGS) is increasingly being employed in the context of personalized cancer treatment. Anticipating unsolicited findings that may arise during a NGS procedure is a key consideration; however, little is known about cancer patients' intentions, needs, and preferences concerning the return of unsolicited findings. METHODS: A qualitative design using individual semi-structured interviews with 24 cancer patients was utilized to explore patients' decisions on whether to receive unsolicited findings from NGS. These interviews were subsequently analyzed using the constant comparative method to develop codes and themes. RESULTS: We identified 4 interrelated themes that emerged in the context of the return of unsolicited findings. First, we describe how cancer patients expressed a strong need to control their lives. Second, we show the importance of family dynamics. Third, the NGS procedure regarding unsolicited findings is perceived as cognitively complex, and fourth, the procedure is also considered emotionally complex. CONCLUSIONS: The results of our study contribute to a better understanding of what cancer patients consider important and what may motivate and influence them when making decisions on the disclosure of unsolicited findings following NGS. We show how Joel Feinberg's classification of autonomy may help clinicians to better understand cancer patients' desire for autonomous decision making while also acknowledging the emotional and cognitive difficulties regarding the disclosure of unsolicited findings. These insights could be helpful for clinicians to guide patients through this complex process.

Implementation of a multi-institutional diffuse intrinsic pontine glioma autopsy protocol and characterization of a primary cell culture.

AIMS: Diffuse intrinsic pontine glioma (DIPG) is a fatal paediatric malignancy. Tumour resection is not possible without serious morbidity and biopsies are rarely performed. The resulting lack of primary DIPG material has made preclinical research practically impossible and has hindered the development of new therapies for this disease. The aim of the current study was to address the lack of primary DIPG material and preclinical models by developing a multi-institutional autopsy protocol. METHODS: An autopsy protocol was implemented in the Netherlands to obtain tumour material within a brief post mortem interval. A team of neuropathologists and researchers was available at any time to perform the autopsy and process the material harvested. Whole brain autopsy was performed and primary DIPG material and healthy tissue were collected from all affected brain areas. Finally, the study included systematic evaluation by parents. RESULTS: Five autopsies were performed. The mean time interval between death and time of autopsy was 3 h (range 2-4). All tumours were graded as glioblastoma. None of the parents regretted their choice to participate, and they all derived comfort in donating tissue of their child in the hope to help future DIPG patients. In addition, we developed and characterized one of the first DIPG cell cultures from post mortem material. CONCLUSION: Here we show that obtaining post mortem DIPG tumour tissue for research purposes is feasible with short delay, and that the autopsy procedure is satisfying for participating parents and can be suitable for the development of preclinical DIPG models.

Impact of integration of clinical and outpatient units on cancer patient satisfaction.

OBJECTIVE: There is an ongoing drive to measure and improve quality of care. Donabedians' quality framework with structure, process and outcome domains provides a useful hold to examine quality of care. The aim of this study was to address the effect of an intervention in hospital structure (integration of three units into one) with the purpose of improving processes (increase meeting, cooperation and communication between professionals and patients) and its effect on the outcome (cancer patient satisfaction). DESIGN: Pre-test-post-test. SETTING: University Medical Center Utrecht, The Netherlands, Department of Medical Oncology. PARTICIPANTS: Cancer patients (n = 174, n = 97). INTERVENTIONS: Physical integration by bringing separately located units (outpatient clinic, day-care clinic, clinical ward) together in one wing of the hospital and adjustments in communication and coordination structures. MAIN OUTCOME MEASURE: Patient satisfaction questionnaire. RESULTS: Satisfaction with care improved for six scales (27%) after integration. Effect sizes (ESs) ranged from 0.36 to 0.80, indicating a small to moderate effect. The most important improvement was found at the day-care clinic on aspects like 'the degree in which the nurses were informed about a patients situation', 'privacy', 'interior design', 'quality of hospital equipment', 'sanitary supplies' and 'waiting periods'. With regard to continuity and coordination of care, satisfaction increased for five items (28% of items concerning continuity and coordination of care). ESs ranged from 0.42 to 0.75. CONCLUSIONS: Integration of three oncology units into one unit had a positive impact on care delivery processes and resulted in improved patient satisfaction concerning care and treatment.

Medical oncology patients' preferences with regard to health care: development of a patient-driven questionnaire.

BACKGROUND: To improve quality of care for cancer patients, it is important to have an insight on the patient's view on health care and on their specific wishes, needs and preferences, without restriction and without influence of researchers and health care providers. The aim of this study was to develop a questionnaire assessing medical oncology patients' preferences for health care based on their own input. PATIENTS AND METHODS: Items were generated using 10 focus group interviews with 51 cancer patients. A preliminary questionnaire was handed out to 681 patients of seven Dutch departments of medical oncology. Explorative factor analysis was carried out on the 386 returned questionnaires (response 57%). RESULTS: Focus group interviews resulted in a preliminary questionnaire containing 136 items. Explorative factor analysis resulted in a definitive questionnaire containing 123 items (21 scales and eight single items). Patients rated expertise, safety, performance and attitude of physicians and nurses as the most important issues in cancer care. CONCLUSION: This questionnaire may be used to assess preferences of cancer patients and to come to a tailored approach of health care that meets patients' wishes and needs.

Aminopeptidase N is directly sorted to the apical domain in MDCK cells.

In different epithelial cell types, integral membrane proteins appear to follow different sorting pathways to the apical surface. In hepatocytes, several apical proteins were shown to be transported there indirectly via the basolateral membrane, whereas in MDCK cells a direct sorting pathway from the trans-Golgi-network to the apical membrane has been demonstrated. However, different proteins had been studied in these cells. To compare the sorting of a single protein in both systems, we have expressed aminopeptidase N, which already had been shown to be sorted indirectly in hepatocytes, in transfected MDCK cells. As expected, it was predominantly localized to the apical domain of the plasma membrane. By monitoring the appearance of newly synthesized aminopeptidase N at the apical and basolateral surface, it was found to be directly sorted to the apical domain in MDCK cells, indicating that the sorting pathways are indeed cell type-specific.

Cytotoxicity of CD3-ricin A chain immunotoxins in relation to cellular uptake and degradation kinetics.

The cytotoxicity of WT32 (CD3)-ricin A immunotoxin (IT) to the acute lymphoblastic leukemia T-cell line Jurkat was compared with the rate of internalization and intracellular degradation of WT32 and WT32-ricin A during continuous exposure. Moreover, the influence of NH4Cl and monensin on these processes was studied. Based on protein synthesis inhibition ([3H]leucine incorporation), it appeared that cytotoxicity was not fully expressed directly after exposure to IT due to a delay in either the internalization of membrane-bound IT or the action of intracellular ricin A. Varying the duration of incubation and postponing [3H]leucine addition for up to 24 h after initiation showed that cytotoxicity occurred in two phases, rapid internalization of initially bound IT followed by a continuous but slower uptake, possibly due to reexpression of the CD3 antigen. No differences were found in the rate of internalization and degradation of 125I-labeled WT32 and WT32-ricin A. Internalization started rapidly after binding at 37 degrees C, was fastest during the first 12 h (+/- 360,000 molecules/cell), and continued for at least 24 h (+/- 420,000 molecules/cell). Exocytosis of intracellularly degraded molecules became measurable after 1 to 2 h of incubation at 37 degrees C and increased to approximately 400,000 molecules/cell in 24 h. After 4 h of incubation at 37 degrees C the number of internalized molecules exceeded the amount of WT32 that could maximally bind to the cell membrane (+/- 150,000 molecules/cell), confirming reexpression of antigen. The addition of NH4Cl and monensin enhanced the cytotoxicity of WT32-ricin A, probably due to an increased intracellular amount of IT. These agents appeared to reduce strongly the degradation of internalized WT32, resulting in an accumulation of intracellular molecules. NH4Cl was most effective during the first 12 h of incubation, whereas monensin increased the amount of intracellular WT32 molecules after 2 to 24 h. Our observations suggest that incubation conditions for the optimal cytotoxicity of IT treatment can be predicted by studying the internalization and degradation of the IT or respective monoclonal antibody.

Effect of isotype on internalization and cytotoxicity of CD19-ricin A immunotoxins.

We analyzed the effect of isotype variation on effectiveness of B-cell CD19 immunotoxins (IT) by using class switch variants (CLB-B4-IgG1 and CLB-B4-IgG2a) conjugated to ricin A. Notably, IgG1-IT appeared to be approximately 100-fold more potent than IgG2a-IT toward B-cell lines Daudi and KM3. Binding and internalization studies with 125I-labeled monoclonal antibodies (mAbs) revealed a higher cellular uptake of IgG1 compared to IgG2a, despite similar binding affinities. Following removal of the Fc part, both mAbs internalized at the same rate as IgG2a, indicating that the Fc part of IgG1 is involved in enhanced cellular uptake. The involvement of Fc gamma RII (CD32) in this process was demonstrated by a decreased cytotoxicity of IgG1-IT (and not IgG2a-IT) in the presence of Fc gamma RII-blocking mAbs AT10 or IV.3. To identify the isoform responsible for this phenomenon, internalization of IgG1 and IgG2a in 11 B-cell lines and malignant B-cells of 8 patients was compared with expression of Fc gamma RII subclasses. In addition to four cell lines (Daudi, KM3, Nalm6, and Raji), the malignant B-cells of two patients showed enhanced uptake of IgG1 relative to IgG2a. Only the Fc gamma RIIa transcript was found in all B-cells. Furthermore, enhanced uptake of IgG1 correlated with rosetting of erythrocytes sensitized with anti-glycophorin A mAb of IgG1 isotype rather than with Fc gamma RIIa membrane expression levels. These data support the idea that functional Fc gamma RIIa is involved in the enhanced IgG1 uptake observed in a subset of B-cells. Our study, therefore, points to an important role for the Fc region of IT in the delivery of cytotoxic effects.

Bacterial Electron Transfer Chains Primed by Proteomics.

Electron transport phosphorylation is the central mechanism for most prokaryotic species to harvest energy released in the respiration of their substrates as ATP. Microorganisms have evolved incredible variations on this principle, most of these we perhaps do not know, considering that only a fraction of the microbial richness is known. Besides these variations, microbial species may show substantial versatility in using respiratory systems. In connection herewith, regulatory mechanisms control the expression of these respiratory enzyme systems and their assembly at the translational and posttranslational levels, to optimally accommodate changes in the supply of their energy substrates. Here, we present an overview of methods and techniques from the field of proteomics to explore bacterial electron transfer chains and their regulation at levels ranging from the whole organism down to the Ångstrom scales of protein structures. From the survey of the literature on this subject, it is concluded that proteomics, indeed, has substantially contributed to our comprehending of bacterial respiratory mechanisms, often in elegant combinations with genetic and biochemical approaches. However, we also note that advanced proteomics offers a wealth of opportunities, which have not been exploited at all, or at best underexploited in hypothesis-driving and hypothesis-driven research on bacterial bioenergetics. Examples obtained from the related area of mitochondrial oxidative phosphorylation research, where the application of advanced proteomics is more common, may illustrate these opportunities.

Genomic acute myeloid leukemia-associated inv(16)(p13q22) breakpoints are tightly clustered.

The inv(16) and related t(16;16) are found in 10% of all cases with de novo acute myeloid leukemia. In these rearrangements the core binding factor beta (CBFB) gene on 16q22 is fused to the smooth muscle myosin heavy chain gene (MYH11) on 16p13. To gain insight into the mechanisms causing the inv(16) we have analysed 24 genomic CBFB-MYH11 breakpoints. All breakpoints in CBFB are located in a 15-Kb intron. More than 50% of the sequenced 6.2 Kb of this intron consists of human repetitive elements. Twenty-one of the 24 breakpoints in MYH11 are located in a 370-bp intron. The remaining three breakpoints in MYH11 are located more upstream. The localization of three breakpoints adjacent to a V(D)J recombinase signal sequence in MYH11 suggests a V(D)J recombinase-mediated rearrangement in these cases. V(D)J recombinase-associated characteristics (small nucleotide deletions and insertions of random nucleotides) were detected in six other cases. CBFB and MYH11 duplications were detected in four of six cases tested.

Antisense BCR-ABL oligonucleotides induce apoptosis in the Philadelphia chromosome-positive cell line BV173.

BCR-ABL antisense oligonucleotides can specifically reduce colony formation of early hematopoietic progenitor cells from chronic myeloid leukemia (CML) patients. Little is known about the mechanism of this inhibition. We studied the inhibition of the bcr-abl oncogene using fluorescein-labeled phosphorothioate oligonucleotides in the Philadelphia chromosome-positive cell line BV173. Oligonucleotide stability, uptake, bcr-abl mRNA degradation, inhibition of cell proliferation, and cell death were studied. The oligonucleotide uptake was directly dependent on the extracellular concentration and was constant over the first 18 h of incubation. After that the uptake rate decreased. We detected a decrease in bcr-abl mRNA after 3 days of treatment with antisense oligonucleotides, but much less in controls. The controls used in the experiments were the sense oligonucleotide, equimolar amounts of sense and antisense, and an untreated control. Antisense oligonucleotides completely inhibited cell growth of BV173 cells and did not inhibit growth of HL-60 cells, whereas control oligonucleotides had no such effect on either cell line. An oligonucleotide specific for the other CML breakpoint was also effective in reducing cell growth of BV173. By the use of a DNA double staining technique to discriminate between necrotic and apoptotic cells, we detected a large number of apoptotic cells in antisense treated BV173 cultures after 5 days of treatment as compared to controls. We conclude that antisense BCR-ABL oligonucleotides reduce bcr-abl mRNA expression in BV173 cells mainly in a sequence-specific manner and induce apoptosis.

Phosphorothioate BCR-ABL antisense oligonucleotides induce cell death, but fail to reduce cellular bcr-abl protein levels.

The bcr-abl oncogene is a fusion gene resulting from a reciprocal translocation which forms the hallmark of chronic myeloid leukemia (CML). Antisense oligonucleotides complementary to the two possible mRNA breakpoints were found to inhibit cell growth of CML patient cells and cell lines, but doubt exists about their specificity. In order to test the specificity, phosphorothioate and 3' phosphorothioate capped antisense BCR-ABL oligonucleotides of different length were used. Stability, cellular uptake of oligonucleotides and effect on cell growth were studied in two CML cell lines, BV173 and LAMA-84. Phosphorothioate antisense BCR-ABL oligonucleotides were most stable, showed the highest uptake and induced cell death in BV173 but not in LAMA-84 cells. We selected the most effective antisense oligonucleotide for further analysis. The BV173 and LAMA-84 cell lines do not express the normal c-abl protein, we therefore used a c-abl specific monoclonal antibody for the detection of p210bcr-abl expression by flow cytometry. Dead cells found after treatment were gated out of analysis. Although BCR-ABL antisense oligonucleotides can induce apoptosis, no reduction of p210bcr-abl levels could be detected in living cells after treatment with antisense oligonucleotides. We conclude that antisense mediated inhibition of translation of mRNA into p210bcr-abl is not the mechanism responsible for the induction of apoptosis in cell line BV173.

A new multichamber counterflow centrifugation rotor with high-separation capacity and versatile potentials.

A new closed system for counterflow centrifugation (elutriation) is described. The system was developed to increase the capacity of counterflow centrifugation in order to be able to separate bone marrow intended for allogeneic bone marrow transplantation within 3 h. The rotor has the capacity for up to four separation chambers, offering the possibility of separating either a single-cell suspension under equal or differing conditions, or four different suspensions simultaneously. Profiles of low-density nucleated cells from normal blood were shown to be identical after elutriation in four different chambers. Leucocytes could be depleted from platelet concentrates without significant loss. Most (98%) of the lymphocytes were removed from donor marrow intended for transplantation within 3 h and the recovery of myeloid and erythroid clonogenic cells in the graft was similar to that obtained from the standard single chamber centrifuge.

Origin of T-lymphocytes in human mixed hematopoietic colonies.

The presence of T-lymphocytes in mixed hematopoietic colonies (CFU-MIX) has been reported by some investigators. Though depletion before culturing was performed, residual T cells might be responsible for the observed phenomenon. Using nondepleted marrow or bone marrow depleted to about 2%, T-lymphocytes could be detected in mixed colonies. However, reduction of the T-lymphocytes to less than 0.7% by using a modified E-rosette technique or a cocktail of anti-T-cell monoclonal antibodies (WT1, WT32, WT82) in the presence of baby rabbit complement, resulted in mixed colonies free of T-lymphocytes. After addition of 1.75% T-lymphocytes to this T-cell-depleted bone marrow, T-lymphocytes could be detected in most mixed colonies, but not after the addition of the same percentage of irradiated T-lymphocytes. The presence of T cells in mixed colonies was determined by an adapted immunofluorescence technique (WT32 plus GAM-FITC). The results indicate that mononuclear cells with T-lymphocyte antigens are not the offspring of mixed hematopoietic colony-forming progenitors, but of a low number of T-lymphocytes contaminating the bone marrow after insufficient T-cell depletion.

Characterization of a novel malignant B cell line with t(14;18) and t(4;11) established from a patient with acute monoblastic leukemia.

The severe combined immunodeficient (SCID) mouse model is an important tool with which to study new strategies for treating hematologic neoplasia. For these experiments, a large number of human cell lines growing in SCID mice are a prerequisite. We describe a new Epstein-Barr virus (EBV)-positive B cell line, designated BEVA, with a complex karyotype including translocations t(14:18)(q32;q21) and t(4;11) (q21;q23) that meets this need. As demonstrated by Southern blot analysis, BCL2 at 18q21, but not MLL/ALL1 at 11q23, was involved in these translocations. BEVA cells coexpressed lymphoid (IgG-kappa, CD19, CD20, CD21, and CD24) and myeloid (CD11b, CD15, and CDw65) markers. Interestingly, the cell line was established from the bone marrow culture of a patient with acute myeloid leukemia (AML). Examination of bone marrow biopsy specimens suggested the presence of non-Hodgkin's lymphoma (NHL) in this patient in addition to AML. In vitro and in vivo growth characteristics of the BEVA cell line were compared with the previously described EBV-positive B cell line DoHH2, also carrying a translocation t(14;18)(q32;q21). These DoHH2 cells additionally expressed CD10, whereas, in contrast to BEVA cells, only a small population of DoHH2 cells showed expression of CD44. Both cell lines showed similar growth characteristics in vitro, but reacted differently to cytokines, including interleukin (IL)-4, IL-6, IL-7, and alpha-interferon (IFN). Upon inoculation in SCID mice, marked differences were observed in the dissemination patterns of the BEVA or DoHH2 cells. Although both cell lines circulated in the blood and were predominantly found in murine bone marrow and lymphoid tissues, DoHH2 cells infiltrated the murine spleens, whereas BEVA cells could only rarely be detected in these tissues. In contrast to DoHH2 cells, BEVA cells gave rise to tumor masses in liver, kidney, and para-aortal or mesenteric lymph nodes. The relationship between these in vitro differences and the observed differences in dissemination of both cell lines is discussed.

Detection of incorporated iododeoxyuridine in colonies by immunoperoxidase staining: a novel method to measure the proportion of cycling colony-forming cells.

In vitro suicide by tritiated thymidine (3H-TdR), hydroxyurea (HU), or cytosine arabinoside (Ara-C) is assumed to reflect the proportion of colony-forming cells in S-phase at the time of exposure. However, these techniques are not always accurate. Nonradioactive iododeoxyuridine (IdUrd) is incorporated into DNA during S-phase and can be detected by monoclonal antibodies. In the present study, a new IdUrd application was developed to investigate the kinetics of hematopoietic progenitor cells. After incubation with IdUrd, colony-forming cells were cultured in semisolid assay. An immunoperoxidase staining protocol was developed to detect IdUrd in cells of colonies in agar. Colony-forming cells in S-phase during the IdUrd exposure were postulated to give rise to IdUrd+ colonies, whereas non-S-phase cells would generate IdUrd- colonies. Toxicity, sensitivity, and IdUrd inactivation studies indicated that progenitor cells could safely be pulse-labeled for 2 hours with 40 microM IdUrd, whereas prolonged labeling with 1 microM IdUrd was at least feasible for 5 days. Molt-4 cells and normal bone marrow cells were used to compare IdUrd pulse-labeling with 3H-TdR suicide. Part of the Molt-4 cells were enriched for G1- and S-phase cells by counterflow centrifugation. The bone marrow cells were either unstimulated or stimulated with growth factors. As a result, the accuracy of both techniques could be tested in populations with different quantities of S-phase cells. Wide confidence intervals of the suicide technique contrasted with the small confidence intervals obtained with IdUrd pulse-labeling. For instance, the fraction of Molt-4 cells with 27.8% S-phase cells contained 17.7% (confidence interval -8.2 to 43.6%) clonogenic cells in S-phase when determined with 3H-TdR suicide. Of this fraction, the percentage of clonogenic cells in S-phase was 30.6% with a confidence interval of 25.5 to 36.2% when determined with IdUrd pulse-labeling. In our hands, the IdUrd pulse-labeling was more accurate than the 3H-TdR suicide technique. Thus far, kinetic studies of progenitors have been limited to the determination of the fraction of S-phase cells by suicide techniques. By prolonged IdUrd labeling, it is now possible to determine the proliferating fraction of progenitor cells.

Male LH-independent sexual precocity in a 3.5-year-old boy caused by a somatic activating mutation of the LH receptor in a Leydig cell tumor.

We describe the clinical features of severe sexual precocity in a 3.5-yr-old boy. Hormonal evaluation showed LH-independent T hypersecretion. Initial examination of the adrenals and testes revealed no evidence of congenital adrenal hyperplasia, hCG- or androgen-secreting tumors, or McCune-Albright syndrome. In the coding sequence of the LH receptor gene no activating mutation was found. Spironolactone (5.7 mg/kg x d) and testolactone (40 mg/kg x d) were unsuccessful in suppressing the elevated concentration of T. To further determine the origin of the elevated serum T, a selective venous sampling procedure was planned. However before the sampling procedure, high resolution ultrasound examination showed a small tumor in the left testis, which was removed. Histology proved the tumor to be a Leydig cell adenoma. Sequencing of the tumor LH receptor gene revealed a heterozygous mutation in exon 11 encoding a replacement of aspartic acid at position 578 with histidine, which has been shown to be a constitutively activating mutation. These findings indicate that in male patients with gonadotropin-independent sexual precocity, the presence of small testicular Leydig cell tumors harboring a somatic mutation of the LH receptor gene should be considered.

Plasma and human leukemic cell pharmacokinetics of oral and intravenous 4-demethoxydaunomycin.

On 3 consecutive days, 4-demethoxydaunomycin (D-DNM) was administered orally (30 mg/m2) as bolus injection and 4- or 24-hour infusion to seven patients with acute leukemia. Cellular (nucleated blood and bone marrow cells) and plasma drug concentrations were studied. After bolus injection, peak plasma D-DNM concentrations were about 50 mg/ml. D-DNM plasma t1/2s were 0.4 +/- 0.3 hours (T1/2 alpha) and 16.4 +/- 4.7 hours (T1/2 beta). D-DNM concentrations in nucleated blood and bone marrow cells were on the same order of magnitude and amounted to more than 400 times the plasma concentration, whereas 4-demethoxydaunomycinol (D-DNMol) concentrations were about 200 times higher. Cellular D-DNM concentrations were maximal at the end of intravenous dosing and at 2 to 4 hours after D-DNM ingestion. D-DNMol concentrations increased more slowly and accumulated on subsequent treatment days in cells and plasma; D-DNM and D-DNMol cellular t1/2 times were 42 and 72 hours, respectively. Antileukemic activity was observed.

Signal peptidase can cleave inside a polytopic membrane protein.

The signal peptides of most proteins targeted to the endoplasmic reticulum are specifically cleaved by signal peptidase. Although potential cleavage sites occur frequently in polytopic proteins after membrane-spanning segments, processing is restricted to the first hydrophobic domain, suggesting that signal peptidase might not have access to subsequently translocated, internal domains. To test this hypothesis, we replaced the third transmembrane segment of an artificial threefold membrane-spanning protein by a sequence which is normally an amino-terminal signal. Upon in vitro translation and insertion into microsomes, efficient cleavage at this sequence was observed, thus demonstrating the ability of signal peptidase to cleave within polytopic membrane proteins.

Bone marrow repopulation capacity after transplantation of lymphocyte-depleted allogeneic bone marrow using counterflow centrifugation.

Bone marrow from six allogeneic HLA-matched and MCL nonreactive siblings was fractionated by means of isopycnic flotation centrifugation and subsequent counterflow centrifugation. The low density fraction (d less than or equal to 1.070 g/ml) obtained by IFC contained 20% of the nucleated cells and more than 90% of the myeloid and erythroid progenitors. The putative stem cell fraction obtained by CC showed a satisfactory recovery (88%) of the CFU-GM and BFU-E and only 3.5% of the original number of T lymphocytes. Bone marrow repopulation capacity was not impaired in comparison with a comparable group of patients. Despite the average high age of this group (29.6 years), only one of the four evaluable patients developed graft-versus-host disease.