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Hemopoietic colony forming units in fresh and cryopreserved peripheral blood cells of canines and man.

Colony forming units (CFUa) were assayed in the peripheral blood and separated mononuclear cells of canines and man. Fresh and cryopreserved samples were studied. By plating 3 x 10-5 canine buffy coat cells or 3 x 10-6 human buffy coat cells between 33 plus or minus 6.6 and 38 plus or minus 1.0 colonies were observed. A high degree of reproducibility was shown for duplicate plates and on repeated testing. Cryopreservation for a one-month period resulted in a minimal recovery of 80 per cent CFUa for canine cells and 96 per cent for human cells. In vivo correlation between peripheral blood CFUa and marrow repopulation was assessed indogs following supralethal whole body irradiation. Prompt repopulation of the marrow was observed and this correlated well with the CFUa assay following infusion of stored buffy coat cells. It was concluded that the peripheral blood of both man and dog have significant numbers of cells with CFUa capabilities that may be potentially useful for marrow grafting purposes.

Animals↗

Effects of cryopreservation on histology and viability of cultured corneal epithelial cell sheets in rabbit.

PURPOSE: To increase the availability of cultured corneal epithelial cell sheets as a replacement for corneal limbal allograft, the effects of cryopreservation on viability of cultured corneal epithelial cells were investigated. METHODS: Normal rabbit corneal limbal tissue was excised, and the cells were cultured with mitomycin C-treated 3T3-J2 cells as a feeder layer. Stratified corneal epithelial cell sheets were obtained within 20 days. All sheets with a diameter of 8 mm were punched out with a biopsy punch and stored in either 10% glycerol or dimethyl surfoxide (DMSO) at -80 degrees C or -196 degrees C for 4 or 12 weeks. After thawing, the sheets were evaluated histologically, and cell viability was analyzed by colorimetric cell viability assay using a tetrazolium salt. RESULTS: Structural damage such as vacuolar degeneration was more clearly observed in the corneal epithelial cell sheets cryopreserved with DMSO than those with glycerol, especially at -80 degrees C, whereas only minor morphologic changes were observed in the corneal epithelial cell sheets cryopreserved in glycerol at both temperatures. Colorimetric cell viability assay revealed that the storage conditions at the lower temperature (-196 degrees C) showed higher cell survival than those at the higher storage temperature (-80 degrees C). The difference between the two cryoprotectants, however, was not significant. Among the conditions used in this study, the samples cryopreserved with glycerol at -196 degrees C showed the highest cell survival rate (70.3 +/- 8.3% and 66.4 +/- 14.7% for 4 and 12 weeks, respectively). The difference between this group and those stored at -80 degrees C was significant for both 4 weeks and 12 weeks of storage using either glycerol or DMSO. Although the cryopreserved cell sheets could not maintain their original layered structure after thawing, viable cell sheets could be regenerated. CONCLUSIONS: The cell survival rates obtained after freezing storage were reasonable; however, the cryopreserved sheets could not maintain their original layered structure. More work needs to be done to better preserve the corneal epithelial cell sheets.

Animals↗

Stress-related hormonal suppression of natural killer activity does not show menstrual cycle variations: implications for timing of surgery for breast cancer.

BACKGROUND: Evidence exists that prognosis in breast cancer may be related to the timing of primary surgery. Fluctuations in natural killer (NK) cells and/or their sensitivity to surgical stress hormones could mediate this phenomenon. We sought to establish, firstly, if there are any numerical or functional changes in NK cells during the course of the menstrual cycle and, secondly, if their prior in vitro incubation with cortisol and adrenaline produced functional change that was more pronounced at a particular point in the cycle. SUBJECTS AND METHODS: Normally menstruating females (n = 10) were sampled at two points (mid-follicular and mid-luteal) during two cycles. NK cell numbers were determined by flow cytometry. Natural killer cell activity (NKA) (unstimulated and following a 2-hour pre-incubation with cortisol and adrenaline) was determined using chromium-51 release assays from peripheral blood mononuclear cells (PBMCs) prepared from cryopreserved samples from the second cycle. RESULTS: NK cell numbers (expressed as a percentage of a standard lymphgate) were significantly higher at the mid-luteal point compared to the mid-follicular point (8.45 +/- 3.71 vs. 6.85 +/- 2.80, p < 0.05, data pooled from both cycles). Corresponding changes in NKA were observed, although these did not reach statistical significance. The mean inhibitory effects of cortisol (67%) and adrenaline (12%) on NKA were significant, but this phenomenon was uninfluenced by cycle point. CONCLUSION: This study supports the role of menstrual cycle-induced alterations in NK cells as a putative mediator of improved survival when surgery for breast cancer is carried out in the follicular phase. However there is no evidence of the cyclical sensitivity of NK cells to the principal surgical stress hormones.

Adult↗

Investigation of functional and morphological integrity of freshly isolated and cryopreserved human hepatocytes.

There is a pressing need for alternative therapeutic methods effective in the treatment of patients with liver insufficiency. Isolated human hepatocytes may be a viable alternative or adjunct to orthotopic liver transplantation in such patients. The purpose of this study was to evaluate the viability and functional integrity of freshly isolated and cryopreserved human hepatocytes, in preparation for a multi-center human hepatocyte transplantation trial. We are currently processing transplant-grade human parenchymal liver cells from nondiseased human livers that are obtained through a network of organ procurement organizations (OPOs). Thus far, sixteen hepatocyte transplants have been performed using hepatocytes processed by our methods. At the time of referral all specimens were deemed unsuitable for transplantation due to anatomical anomalies, high fat content, medical history, etc. Hepatocytes were isolated from encapsulated liver sections by a modified two-step perfusion technique. Isolated cells were cryopreserved and stored in liquid nitrogen for one to twelve months. The total yield of freshly isolated hepatocytes averaged 3.7x10(7) cells per gram of wet tissue. Based on trypan blue exclusion, fresh preparations contained an average of 85% viable hepatocytes vs. 70% in cryopreserved samples. The plating efficiencies of cells seeded immediately after isolation ranged from 87% to 98%, while those of cryopreserved/thawed cells were markedly lower. Flow cytometry analysis of cells labeled with 5,6-carboxyfluorescein diacetate succinimidyl ester (CFSE) showed that there was no significant difference in viability compared with trypan blue staining. Both freshly isolated hepatocytes and those recovered from cryopreservation showed typical and intact morphology as demonstrated by light and electron microscopy. The product of the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) reaction was always expressed more intensely in cultures of freshly isolated hepatocytes. Measurements of lactate dehydrogenase (LDH) leakage were inversely correlated with trypan blue exclusion and CFSE labeling. Energy status, evaluated by the intracellular ATP concentration measurements, and various liver-specific functions such as urea synthesis and metabolism of 7-ethoxycoumarin were maintained both in fresh and cryopreserved/thawed hepatocytes. However, the activities were expressed at different levels in thawed cells. These data illustrate the importance and feasibility of human hepatocyte banking. In addition, it is clear that further refinements in the methods of hepatocyte isolation and cryopreservation are needed to utilize more fully these valuable cells in the clinic.

Journal Article↗

Measurement of absolute concentration and viability of CD34+ cells in cord blood and cord blood products using fluorescent beads and cyanine nucleic acid dyes.

Conventional flow cytometric methods for CD34+ cell counting may be affected by the high number of nucleated red blood cells or nonviable cells in cord blood and its products. We developed a simple flow cytometric no-wash procedure that avoids these shortcomings because it provides absolute CD34+ cell counts and assesses cell viability. Samples were incubated with phycoerythrin (PE)-labeled anti-CD34 (Becton Dickinson Immunocytometry Systems [BD], San Jose, CA) and peridinin chlorophyll protein (PerCP)-labeled anti-CD45 (BD) in bead-containing TRUCOUNT tubes (BD). After red cell lysis with a fixative-free reagent, the impermeant nucleic acid dye YO-PRO-1 (Molecular Probes, Eugene, OR) was added and samples were analyzed on a single-laser FACSCalibur (BD). A comparison with the ProCOUNT progenitor cell assay (BD) in 57 samples revealed excellent correlation of results (r = 0.98, intercept -0.2 cells/microl, slope 1.01). Precision studies conveyed coefficients of variation of 6.4 and 8.9% at concentrations of 35 and 16 CD34+ cells/microl, respectively. In untreated and leukocyte-enriched cord blood 4.5+/-3.8% of CD34+ cells were stained by YO-PRO-1, representing apoptotic or necrotic cells. In post-thawing cryopreserved samples this number increased to 10.4+/-5.5%. Isotype controls showed very low blank values of viable cells (0.1+/-0.4 cells/microl, maximum 2.4) and seemed unnecessary. We found no washing-related alteration of results in 35 samples, indicating that the method may also be performed with cell washing. Replacing YO-PRO-1 with TO-PRO-3 facilitated four-color analysis of subpopulations of viable CD34+ cells on a FACSCalibur equipped with a second (diode) laser. We found the proposed method to be a rapid, efficient, and flexible procedure that improved validity of CD34+ cell counts.

Antigens, CD34↗

Chemosensitivity of human tumor clonogenic cells simultaneously assayed in agar diffusion chambers and in a two-layer agar culture system.

We have compared plating efficiencies (PE) of 20 fresh and cryopreserved samples of human solid tumors, disaggregated and cloned simultaneously in a two-layer agar culture system (2LACS) and in agar diffusion chambers (ADC). A significant correlation (0.001 less than P less than 0.01, paired t test) was found between PE, confirming that the two methods reflect the same property of tumor cells: their clonogenic potential. The median PE in ADC was 1.4 and 3.3 times higher than that in the 2LACS for cryopreserved and fresh specimens, respectively. One- and two-drug doses, approximately clinically achievable concentrations, were assayed simultaneously in the ADC and in the 2LACS, respectively, on 15 tumor specimens. In this way we evaluated the effects of eight drugs, two to five for each tumor, in a static (2LACS) versus a dynamic (ADC) system. The comparison of percent survival in ADC versus that in the 2LACS at both concentrations tested showed no statistically significant rank correlation. If the data regarding cyclophosphamide and mitomycin, which produced significant cell kill in the ADC and almost none in the 2LACS, were excluded, the rank correlation was still not significant. We conclude that the widely used 2LACS is unsuitable to study cyclophosphamide and mitomycin, for which the ADC technique may be a valid alternative.

Agar↗

Contamination of transplantable human tumor-bearing lines by Helicobacter hepaticus and its elimination.

Helicobacter hepaticus contaminating nonfrozen tumors was transmissible to severe combined immunodeficient (SCID) mice, but the organism in cryopreserved samples was not. This suggests that H. hepaticus has the ability to spread via biomaterials and that freezing-thawing is able to reduce the numbers of organisms to levels insufficient for subcutaneous infection of SCID mice.

Animals↗

Comparison of assessment of fowl sperm viability by eosin-nigrosin and dual fluorescence (SYBR-14/PI).

The kinetics of fowl sperm viability/mortality following short-term and long-term in vitro storage were studied using 2 different staining methods: eosin/nigrosin (observed under light microscopy) and SYBR-14/PI (dual fluorescence). Based on data obtained at 0, 30 min and at 2, 4 and 24 h (T0, T30, T2, T4, and T24) after in vitro storage (4 degrees C, agitated) of fresh or frozen-thawed semen, the dual association SYBR-14/PI was more effective than eosin/nigrosin (P < 0.05) staining for the detection of sperm viability/mortality at early stages (30 min) in nonfrozen ejaculates stored above 0 degree C. In cryopreserved preparations, the 2 techniques were comparable for assessing viable spermatozoa immediately after thawing, but higher percentages (P < 0.05) of nonviable spermatozoa were detected by the SYBR-14/PI procedure for up to 4 h of in vitro storage post thawing (4 degrees C, agitated). Finally, comparable results were observed between the 2 techniques 24 h after beginning in vitro storage post thawing. It is concluded that the dual association SYBR-14/PI procedure is more effective (or, at least, more rapid) than eosin/nigrosin staining for the assessment of sperm viability/mortality in both fresh and cryopreserved samples of fowl semen. However, in the latter case, the thawing stage needs to be followed by a period of in vitro storage lasting at least 4 h to allow for easier discrimination between viable and nonviable populations of spermatozoa.

Aniline Compounds↗

Study of DNA damage induction and repair capacity of fresh and cryopreserved lymphocytes exposed to H2O2 and gamma-irradiation with the alkaline comet assay.

The alkaline SCGE assay was evaluated for use with cryopreserved lymphocytes in order to obtain results similar to the freshly isolated ones. The induction of DNA damage as well as the repair capacity of gamma-rays and H2O2 exposed cryopreserved human lymphocytes was found to be the same to that of the freshly isolated. Human lymphocytes (fresh or cryopreserved) responded differently to the effects of gamma-irradiation if compared to the H2O2 treatment. The distribution of DNA damage among gamma-irradiated lymphocytes was more homogeneous compared to H2O2, both in freshly isolated and in cryopreserved cells. 2.4 micrograms/ml phytohemagglutinin at the start of a 2-h incubation in RPMI of cryopreserved samples gave similar DNA repair and distribution patterns to the 2-h post-exposure incubation of freshly isolated lymphocytes. H2O2-induced DNA damage was not repaired completely. However, the repair of gamma-rays-induced DNA damage was more efficient. These findings confirm the different mode of action of the two agents on the induction of DNA damage, as well as, the different response of the lymphocytes' DNA repair system.

Cryopreservation↗

[Viability of parathyroid gland tissue measured by flow cytometry].

BACKGROUND: Postoperative hypoparathyroidism after the total parathyroidectomy (PTX) remains a problem, no matter our experiences with 243 operations on parathyroid glands (PG). Implantation of "fresh" tissue, cryopreservation and reimplantation of cryopreserved tissue are performed with uncertain results. The aim of this project was to compare viability of cryopreserved tissue of parathyroid glands with "fresh" tissue obtained during parathyreoidectomy and with tissue from cadaverous donors. METHODS AND RESULTS: Group 1 included 55 cryopreserved samples obtained from 41 patients after PTX (22M, 19F, a mean age of 46 +/- 11 years). Average duration of storage in liquid nitrogen was 84 +/- 49 months. Group 2 included "fresh" tissue of PG, harvested during PTX. Viability was measured in different time in samples from 42 patients with hyperparathyroidism (11M, 31F, a mean age of 55 +/- 13 years). Group 3 included tissue of 14 cadaverous donors obtained during multiorgan harvesting (7M, 7F, a mean age of 31 +/- 5 years, WIT 32 min). Viability was measured by flow cytometry with propidium iodide after dissociation of tissue. Evaluation of PG tissue was proven by histology. Average viability in group 1 was 36.9 +/- 24.7%, no correlation with the duration of storage in liquid nitrogen was found. Average viability in group 2 was 51.4 +/- 24%. Viability in group 3 was 66.8 +/- 32%. Group 1 vs. group 2 were different with p < 0.05, group 2 vs. 3 did not reach significance (with marginal p = 0.06) and group 1 vs 3 were different with p < 0.001. CONCLUSIONS: The highest viability was found in tissue of cadaverous donors, the lowest in cryopreserved tissue (with no correlation to the duration of storage in liquid nitrogen).

Cadaver↗

DNAse treatment following thawing of cryopreserved PBMC is a procedure suitable for lymphocyte functional studies.

Testing freshly isolated PBMC is not practical for immune monitoring analysis in large clinical trials or natural history studies. Thus, cryopreserved PBMC represent a more practical alternative. However, cell clumping is a common problem following thawing of PBMC isolated from blood that was previously transported and stored. Cell clumping leads to loss of cells, and could affect cell function and/or phenotype. The development and validation of procedures that prevent cell clumping and preserve cell function and surface marker expression levels are necessary to allow evaluation of immune function and phenotype in cryopreserved samples from clinical studies. The incorporation of a DNAse treatment step in the standard thawing procedure efficiently avoided clump formation, and did not result in detectable changes in cell viability, expression of standard leukocyte surface markers or two key parameters of immune function, proliferation and cytokine induction in response to a variety of common stimuli. Therefore, this procedure seems suitable for standard immunologic assays.

Antigens↗

Flow cytometric assessment of hematopoietic cell subsets in cryopreserved preterm and term cord blood, influence of obstetrical parameters, and availability for transplantation.

OBJECTIVE: The aim of this study was to characterize the lymphocyte and the hematopoietic stem and progenitor cell (HPC) subsets of cryopreserved premature cord blood (PCB) compared to term cord blood (TCB) by flow cytometry, to study the influence of birth conditions, and to assess its availability for transplantation. MATERIALS AND METHODS: Four-color flow cytometric analysis was performed on 43 PCB and 40 TCB cryopreserved samples using a panel of 24 different mAbs, directed against lymphoid and HPC surface markers. The CB volume was estimated by the weight of the newborn to determine the absolute MNC and CD34(+) cell content/CB sample. Clinical and obstetrical data were recovered. Statistical comparisons and a multiple regression analysis were performed. RESULTS: No consistent differences were found in the mononuclear cell (MNC) or CD34(+) cell concentration (x10(6)/L) between PCB and TCB. The percentage of primitive HPC (CD34(+)CD38(-), CD34(+)CD38(-)CD90(-)HLA-DR(-), CD34(+)CD38(-)CD90(-)HLA-DR(+)) and primitive lymphoid progenitors (CD34(+)CD7(+), CD34(+)CD7(+)CD19(-)CD117(-)) were higher in PCB than in TCB. Correspondingly, TCB had an increased percentage of committed HPC. No sample of PCB contained >2 x 10(7) MNC/kg (and only 48% had >1 x 10(5) CD34(+) cells) for a recipient of 20 kg body wt, as the minimum threshold recommended for CB transplantation. Obstetrical factors modulated mainly lymphocyte subsets and fewer HPC subpopulations. Acute fetal distress increased CD34(+) cells, especially the immature subsets. Maternal treatment with dexamethasone and intrauterine growth retardation decreased CD3(+) cells. No other obstetrical factors played a detrimental effect on CB cells if used for transplantation. CONCLUSION: PCB is richer in immature cells both in lymphocyte and HPC populations, and its use for transplantation, at least in special cases, should be reconsidered.

Antigens, Differentiation↗

Diagnostic performance of the urinary bladder carcinoma antigen ELISA test and multiparametric DNA/cytokeratin flow cytometry in urine voided samples from patients with bladder carcinoma.

BACKGROUND: The objective of the current study was to comparatively analyze the sensitivity and specificity of flow cytometric DNA/cytokeratin 8/18 measurements and the urinary bladder carcinoma antigen (UBC) enzyme linked immunoabsorbent assay (ELISA) test for the detection of bladder carcinoma in voided urine samples. METHODS: Eighty-one fresh urine voided samples, preserved frozen for a maximum period of 3 months, belonging to patients with an active bladder carcinoma (n = 37), patients who were free of disease as confirmed by cystoscopy (n = 19), patients receiving intravesical therapy (n = 17), and individuals with other benign and malignant conditions (n = 8), were collected. Flow cytometry measurements of thawed samples were based on the detection of cytokeratin (CK) 8+ and CK18+ cells using the 3F3 and 6D7 monoclonal antibodies alone or in combination with the measurement of cell DNA contents, after propidium iodide staining. Urinary bladder carcinoma antigen test was measured by ELISA. RESULTS: Patients were grouped according to the presence (n = 44) or absence (n = 29) of bladder carcinoma as confirmed by cystoscopy, and taking cutoffs of 9.7 microg/L for UBC-ELISA, 75% for the percentage of 3F3 (+) and 6D7 (+) cells, and 10.6% for the proportion of hyperdiplod cells that suggested a specificity of 83%, the individual sensitivity obtained for each parameter was 77%, 5%, 9%, and 77%, respectively. The presence of DNA aneuploid populations showed a relatively low sensitivity (36%) although it was the most specific parameter (93%). Combining UBC antigen test with the proportion of cells showing DNA content higher than 2n increased to 89% the sensitivity of the UBC antigen alone. However, false-positive results for both techniques were found in individuals with urologic diseases other than bladder carcinoma and in patients receiving intravesical therapy. CONCLUSIONS: The authors' results suggest that the combined use of the UBC antigen test and DNA/cytokeratin flow cytometry double stainings for the analysis of freshly obtained urine voided samples, cryopreserved to assure cellular integrity, is of great clinical utility for the detection of tumor recurrence in patients with bladder carcinoma.

Aged↗

Bcl-2 proto-oncogene expression in Epstein-Barr-virus-associated nasopharyngeal carcinoma.

The bcl-2 proto-oncogene product inhibits apoptosis. Increased levels of bcl-2 protein are associated with prolonged B-cell survival and have been demonstrated in a high proportion of follicular B-cell lymphoma. Recent studies have shown that bcl-2 protein expression in B cells immortalized by Epstein-Barr virus (EBV) in vitro is up-regulated by the EBV-latency-associated antigen, latent membrane protein (LMP) 1. The epithelial malignancy, undifferentiated nasopharyngeal carcinoma (UNPC), has a well-established association with EBV and the tumour cells characteristically display a restricted latent viral phenotype including LMP 1. This study has investigated the relationship between the presence of EBV DNA, EBV phenotypic profiles and bcl-2 protein expression in conventionally processed and cryopreserved samples of NPC using in situ hybridization, immunocytochemical and immunoblotting techniques. bcl-2 was detected in most (80%) samples of UNPC as well as in 1/3 samples of keratinizing NPC and 2/2 samples of nasopharyngeal adenocarcinoma. However, no close correlation was found between the presence of EBV DNA, and profiles for LMP 1 and bcl-2 protein expression in 45 UNPC. In addition, bcl-2 protein was shown to be selectively expressed in the basal compartment of normal nasopharyngeal epithelia. bcl-2 protein expression has not been reported previously in malignant tumours of epithelial origin. The findings in this study implicate a role for bcl-2 both in normal keratinocyte differentiation and in the pathogenesis of epithelial malignancy.

Adenocarcinoma↗

The effect of cryopreservation on the biomechanical behavior of bovine articular cartilage.

The short-term effect of cryopreservation on specific mechanical behaviors of bovine articular cartilage has been investigated. A flat-ended nonporous indentor was used in a nondestructive, repetitive, axisymmetric unconstrained testing system. Cyclical indentation from a fixed position to a fixed load was applied until a steady-state load-deformation relationship (limit cycle) was achieved. Indentation behaviors measured from the limit cycles of each articular cartilage specimen before and after treatment were compared. Testing was done in vitro using fresh, mature bovine radiocarpal joints. Twenty pairs of cartilage-subchondral bone cores from anatomically similar sites on contralateral joints were separated into three groups; thickness controls, dimethylsulfoxide (DMSO) controls, and cryopreserved experimental samples. Thickness controls and DMSO controls were used to examine the isolated effects of the thickness measurement and DMSO incubation techniques on articular cartilage indentation characteristics. Experimental samples were cryopreserved using DMSO, their thicknesses similarly measured and indentation behaviors examined. Following testing, histological and histochemical assessment of the specimens confirmed the nondestructive nature of the tests. Intra- and intergroup comparisons of controls and experimentals revealed no statistical differences in the mechanical behaviors measured from the limit cycle or in cartilage thickness. These results indicate that the cryopreservation protocol used did not have an effect that we could measure on these specific mechanical behaviors of articular cartilage.

Animals↗

The prognostic significance in HIV infection of immune activation represented by cell surface antigen and plasma activation marker changes.

One hundred and eighteen HIV-infected homosexual men without AIDS and 40 control seronegative homosexual men were assessed for 23 parameters reflecting immune activation to determine prognostic significance for occurrence of AIDS. Samples cryopreserved in 1987-1989 were analyzed, with AIDS occurrence determined by mid-1992. Cell surface antigens assessed on the major lymphocyte subsets were HLA-DR, CD38, CD71, and CD25. Soluble serum molecules assessed were tumor necrosis factor alpha, soluble TNFalpha receptor II, soluble IL-2 receptor alpha, neopterin, and beta2-microglobulin. Using a proportional hazards model, prognostic markers included decreased CD4 number and percentage; increased sIL-2R, neopterin, and beta2M; increased percentage HLA-DR+ total lymphocytes and CD4+ cells; increased CD38+ total lymphocytes and CD8+ cells; increased CD71+ total lymphocytes and CD4+ cells; and decreased CD25+ total lymphocytes and CD19+ cells. After adjustment for CD4 cell levels, sIL-2R, neopterin, beta2M, and CD25+ CD19 cells remained significant, indicating that additional information about AIDS risk was provided by these markers.

ADP-ribosyl Cyclase↗

Factors influencing G-CSF-mediated mobilization of hematopoietic progenitor cells during steady-state hematopoiesis in patients with malignant lymphoma and multiple myeloma.

We retrospectively analyzed factors influencing PBPC mobilization during steady-state hematopoiesis in 52 patients with malignant lymphoma (n=35) or multiple myeloma (n=17) who received 77 cycles of G-CSF (12.5-50 microg G-CSF/kg/day). For 15 of these patients, the first mobilization cycle (12.5 microg G-CSF/kg/day) was followed by a second course with an increased dose of G-CSF (25 or 50 microg/kg/day). Leukapheresis was started on day 4, about 2 h after s.c. G-CSF administration, and repeated on 2-5 consecutive days. CD34+ cells were determined by flow cytometry in each apheresis product and in the peripheral blood prior to G-CSF administration, beginning on day 4. Colony assays were performed on cryopreserved samples prior to autografting. In the 15 patients receiving two mobilization cycles the higher G-CSF dose was associated with higher levels of CD34+ cells, a higher mean yield of CD34+ cells per apheresis (p<0.05), and a higher percentage of successful (>2x10(6) CD34+ cells/kg) collections (p=0.058). Patients with limited previous cytotoxic therapy (n=19, up to six cycles of a standard regimen such as CHOP and/or less than 20% marrow irradiation) who received a daily dose of 12.5 microg G-CSF/kg had higher levels of circulating CD34+ cells, a higher mean yield of CD34+ cells per apheresis (p<0.05), and a higher percentage of successful collections (p<0.05) compared with patients previously treated with more intensive radiochemotherapy (n=15). Ten of 20 patients (50%) who failed during the first cycle were successful during subsequent cycles with escalated doses of G-CSF. Trough levels of circulating CD34+ cells on day 4 were predictive for success or failure to achieve >2x10(6) CD34+ cells/kg, especially in heavily pretreated patients. In conclusion, a daily dose of 12.5 microg G-CSF/kg seems sufficient to mobilize PBPC during steady-state hematopoiesis in the majority of patients who have received limited previous radiochemotherapy. Higher doses of G-CSF, up to 50 microg/kg/day, mobilize more PBPC and should be considered for patients previously treated with intensive radiochemotherapy or those failing to mobilize sufficient numbers of CD34+ cells with lower doses of G-CSF.

Adult↗

A monoclonal antibody to common acute lymphoblastic leukemia antigen (neutral endopeptidase) immunostains senile plaques in the brains of patients with Alzheimer's disease.

We immunostained brain tissues of patients with Alzheimer's disease (AD) together with non-demented aged and younger controls with a battery of anti-human hemopoietic cell monoclonal antibodies (OK series, Ortho Diagnostics Co., Ltd. and some others) by the avidin-biotin-peroxidase complex (ABC) method to see if any epitopes are shared with the nervous system or might contribute to the neurodegenerative changes in this disease. One out of 29 monoclonal antibodies, OKBcALLa, which recognizes common acute lymphocytic leukemia antigen (CALLA, CD10), immunostained senile plaques in the brains of patients with AD. The pattern and intensity of this staining, using cryopreserved samples, was almost identical to that obtained with anti beta-protein. Thus, senile plaques in the Alzheimer's brain share an epitope with CALLA.

Aged↗