Foreign Bodies in the Ear, Nose and Throat: An Experience in a Tertiary Care Hospital in Central Nepal

Introduction A foreign body (FB) is an object or substance foreign to the location where it is found. FBs in the ear, nose, and throat are a common problem frequently encountered in both children and adults. Objective To analyze FBs in terms of type, site, age, and gender distribution and method of removal. Methods A retrospective study was performed in a tertiary care hospital in the central part of Nepal. The study period was from June 2013 to May 2014. The information was obtained from hospital record books. Results A total of 134 patients had FBs in the ear, nose, or throat; 94 were males and 40 were females. Of the 134 patients, 70 (52.23% ) had FB in the ear, 28 (20.89% ) in the nose, and 36 (26.86% ) in the throat. The FB was animate (living) in 28 (40% ) patients with FB in the ear and 1 (3.5% ) patient with FB in the nose, but the FB was inanimate (nonliving) in any patient with FB in the throat, in 42 (60% ) patients with FB in the ear FB, and in 27 (96.4% ) patients with FB of the nose. The FB was removed with or without local anaesthesia (LA) in 98 (73.13% ) patients, and only 36 patients (26.86% ) required general anaesthesia (GA). The most common age group affected was <10 years. Conclusion FBs in the ear and nose were found more frequently in children, and the throat was the most common site of FB in adults and elderly people. Most of the FBs can be easily removed in emergency room or outpatient department. .

Microambiente medular en la leucemia mieloide crónica: su relación con la enfermedad y la respuesta al tratamiento / Bone marrow microenvironment in chronic myeloid leukemia: Implications for disease physiopathology and response to treatment

Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm related to the presence of the BCR-ABL1 fusion gene, linked to t (9;22) (q34;q11). It is originated from an abnormal hematopoietic stem cell, which is characterized as its normal counterparts by long-term self-renewal and multi-lineage differentiation. Both leukemic and quiescent normal hematopoietic stem cells preferentially reside in the osteoblastic niche. Mesenchymal stromal cells (MSC) are located near them, playing a critical role in their regulation. Currently, with tyrosine kinase inhibitor (TKI) therapy, long term clinical responses are achieved in most CML cases. However, late treatment failures may be observed related to the persistence of leukemic stem cells. The interactions between the leukemic stem cell and the microenvironment may be responsible in part for these events. We review the interactions between the leukemic stem cell and BM stroma and its potential clinical and therapeutic implications.

Obtención y procesamiento de progenitores hematopoyéticos de sangre periférica para terapia celular en enfermedades angiológicas / Obtaining and processing of peripheral blood hematopoietic progenitor cells for cell therapy of angiological diseases

Se evaluó la seguridad y efectividad de un método manual de recolección de células progenitoras hematopoyéticas de sangre periférica movilizadas con factores estimuladores de colonias granulocíticas (FEC-G) de producción nacional (Leukocim y Hebervital). Se estudiaron 250 pacientes seleccionados para terapia celular en el Servicio de Angiología del Hospital General Docente Enrique Cabrera. La obtención y separación de las células mononucleares autólogas de sangre periférica (CMN-SP) se realizó mediante el método diseñado en el Instituto de Hematología e Inmunología. Para valorar la eficacia del método se analizaron en el concentrado obtenido las variables: contenido de células nucleadas, de células mononucleadas y de células CD 34+. Además, se determinó la viabilidad celular y la contaminación microbiológica. Se comprobó la eficiencia y seguridad del método de recolección y procesamiento para la obtención de un concentrado con un contenido de células mononucleares adecuado, sin complicaciones de importancia clínica. Se demostró la eficacia de los factores estimuladores de colonias granulocíticas empleados. Los efectos adversos de la movilización resultaron ligeros e independientes del factor estimulador utilizado

The safety and effectiveness of a manual collection method of peripheral blood hematopoietic progenitor cells mobilized by the Cuban-made granulocytic colony-stimulating factors (Leukocim and Hebervital) were evaluated. Two hundred patients, who had been selected for the cell therapy at the Angiology Service of Enrique Cabrera General Teaching Hospital, were studied. The method designed by the Institute of Hematology and Immunology served to obtain and separate autologous mononuclear cells from the peripheral blood. For the purpose of assessing the efficacy of this method, the variables contents of nucleate cells, of mononucleate cells and of CD 34+ cells were analyzed in the final concentrate. Additionally, the cell viability and the microbiological pollution were determined. The efficiency and safety of the collecting and processing method for obtaining one concentrate with adequate content of mononuclear cells and no significant clinical complications was confirmed. The efficacy of the Cuban granulocytic colony-stimulating factors was proved. The adverse effects of the mobilization were mild and unrelated to the used stimulating factor

Actualización en trasplante de células progenitoras hematopoyéticas en pacientes pediátricos en los últimos 15 años / Updating in transplant of hematopoietic progenitor cells in pediatric patients during the past 15 years

En el pasado año 2010 se conmemoró el 25º aniversario de la introducción en Cuba del trasplante de médula ósea, y su desarrollo ha seguido la secuencia de la historia universal del trasplante hematopoyético. En este trabajo nos referimos a los logros más importantes que se han alcanzado en los últimos 15 años, como ha sido la introducción del trasplante con células movilizadas hacia la sangre periférica. Se exponen los resultados parciales de un estudio comparativo de 2 grupos de pacientes pediátricos, uno que recibió células progenitoras hematopoyéticas obtenidas de médula ósea y otro con células movilizadas hacia la sangre periférica mediante factores de crecimiento hematopoyéticos. Otros avances han sido: la introducción del trasplante no mieloablativo en el año 2002, la aplicación de factores recombinantes producidos en Cuba en el manejo de los pacientes trasplantados, y la introducción de técnicas de quimerismo. Se analizan diferentes aspectos relacionados con la histocompatibilidad y los requerimientos para mejorar los resultados del trasplante. Se señala la contribución que ha tenido la experiencia obtenida con este proceder, para el desarrollo de la medicina regenerativa

In the past year 2010, it was commemorate the 25 Anniversary of introduction in Cuba of the bone marrow transplantation and its development has followed the sequence of the universal history of the hematopoietic transplantation. In present paper authors made reference to more important achievements over the past 15 years including the introduction of the transplantation with mobilized cell to peripheral blood. Partial results of a comparative study of 2 groups of pediatric patients are showed; one received hematopoietic progenitor cells obtained from the bone marrow and other with cells mobilized to the peripheral blood by means of hematopoietic growth factors. Other advances include: the introduction of non-myeloablation transplantation in 2002, the application of recombinant factors produced in Cuba in the management of transplanted patients and the introduction of chimerism. Different features related to histocompatibility are analyzed as well as the requirements to improve the transplantation results. It is indicated the contribution of the experience obtained with this procedure for the development of the regenerative medicine

Epiblast embryo stem cells give origin to adult pluripotent cell populations: primordial germ cell, pericytic and haematopoyetic stem cells: a review / Las células madre del epiblasto dan origen a poblaciones de células pluripotentes adultas: células germinales primordiales, células madre pericíticas y hematopoyéticas: revisión

Adult stem cells are great promise to the future of regenerative therapy, and understanding of its embryonic origin permit the discrimination of stem cell sources. Embryonic stem cells derived from inner cell mass of blastocyst originate the primordial germ cells, and pericyte stem cell associated to vessels endothelium in yolk sac. Currently, it is being proposed that embryonic primordial germ cell could originate hematopoietic stem cells based on the detection of germ cell markers (SSEA-1/TEC-1, Oct-4 and Nanog) in stem cell harvested from fetal liver and bone marrow. However, different experimental evidence points at two separate differentiation routes toward primordial germ cells, and hematopoietic stem cell with the same embryonic origin. The expression of undifferentiated stem cell markers in umbilical cord and placental vessels, such CD34, CXCR4, c-kit and OCT4 demonstrates the intimate relation between pericyte stem cells, endothelium, haematopoiesis, and primordial germ cells, which all originate from embryonic stem cell from the inner cell mass epiblast.

Las células madre adultas son una gran promesa para el futuro de la terapia regenerativa, y la comprensión de su origen embrionario permite la discriminación de las fuentes de células madre. Las células madre embrionarias derivadas del macizo celular interno del blastocisto originan las células germinales primordiales, y células madre pericíticas asociadas al endotelio de los vasos del saco vitelino. En la actualidad, se propone que las células germinales primordiales embrionarias podrían originar a las células madre hematopoyéticas sobre la base de la detección de marcadores de células germinales (SSEA-1/TEC-1 oct-4 y Nanog) en células madre extraídas de hígado fetal y médula ósea. Sin embargo, diferentes evidencias experimentales apuntan hacia dos vías separadas de diferenciación en células germinales primordiales, y en células madre hematopoyéticas con el mismo origen embrionario. La expresión de marcadores de células madre no diferenciadas en el cordón umbilical y los vasos de la placenta, como CD34, CXCR4, c-kit y OcT4 demuestra la íntima relación entre las células madre pericíticas, el endotelio y las células germinales primordiales, las que se originan en células madre embrionarias a partir del epiblasto del macizo celular interno.

Protein-energy malnutrition halts hemopoietic progenitor cells in the G0/G1 cell cycle stage, thereby altering cell production rates

Protein energy malnutrition (PEM) is a syndrome that often results in immunodeficiency coupled with pancytopenia. Hemopoietic tissue requires a high nutrient supply and the proliferation, differentiation and maturation of cells occur in a constant and balanced manner, sensitive to the demands of specific cell lineages and dependent on the stem cell population. In the present study, we evaluated the effect of PEM on some aspects of hemopoiesis, analyzing the cell cycle of bone marrow cells and the percentage of progenitor cells in the bone marrow. Two-month-old male Swiss mice (N = 7-9 per group) were submitted to PEM with a low-protein diet (4 percent) or were fed a control diet (20 percent protein) ad libitum. When the experimental group had lost about 20 percent of their original body weight after 14 days, we collected blood and bone marrow cells to determine the percentage of progenitor cells and the number of cells in each phase of the cell cycle. Animals of both groups were stimulated with 5-fluorouracil. Blood analysis, bone marrow cell composition and cell cycle evaluation was performed after 10 days. Malnourished animals presented anemia, reticulocytopenia and leukopenia. Their bone marrow was hypocellular and depleted of progenitor cells. Malnourished animals also presented more cells than normal in phases G0 and G1 of the cell cycle. Thus, we conclude that PEM leads to the depletion of progenitor hemopoietic populations and changes in cellular development. We suggest that these changes are some of the primary causes of pancytopenia in cases of PEM.

El ciclo celular y su papel en la biología de las células progenitoras hematopoyéticas / The cell cycle and its role in the biology of haematopoietic progenitor cells

El ciclo celular constituye el conjunto de eventos que determinan la actividad metabólica de toda célula así como su división y la generación de células hijas. Este proceso está involucrado en todos los procesos celulares tales como proliferación y diferenciación. Se ha demostrado que diversos elementos moleculares participan en su regulación y que alteraciones en este proceso pueden conducir a trastornos fisiológicos e incluso a la muerte del organismo. En los mamíferos, uno de los tejidos con mayor recambio celular es el hematopoyético, por lo que se requiere un control muy estricto del ciclo celular, principalmente a nivel de células troncales y progenitoras para la óptima producción de células sanguíneas. En este artículo presentamos un panorama general de los principales mecanismos y factores involucrados en la regulación del ciclo celular, poniendo particular énfasis en su papel en la biología de las células hematopoyéticas primitivas.

The cell cycle comprises a group of biological events that determine the metabolic activity of any cell, as well as its division and the generation of new daughter cells. It is involved in every cellular process, such asproliferation and differentiation. It has been shown that several molecular elements regulate the cell cycle, and that alterations in any of its phases and/or regulators could give rise to physiologic deficiencies, and even death. In mammals, the haematopoietic tissue is one of the most active in terms of cell replacement; thus, a tight cell cycle control, particularly at the level of stem and progenitors cells is crucial for optimal blood cell production. In the present article, we give a comprehensive overview of the major mechanisms and regulatory, molecules that participate in the cell cycle of mammalian cells, with particular emphasis on its role in the biology of primitive cells of the hematopoietic system.

The role of osteoblasts in regulating hematopoietic stem cell activity and tumor metastasis

Bone marrow stromal cells are critical regulators of hematopoiesis. Osteoblasts are part of the stromal cell support system in bone marrow and may be derived from a common precursor. Several studies suggested that osteoblasts regulate hematopoiesis, yet the entire mechanism is not understood. It is clear, however, that both hematopoietic precursors and osteoblasts interact for the production of osteoclasts and the activation of resorption. We observed that hematopoietic stem cells (HSCs) regulate osteoblastic secretion of various growth factors, and that osteoblasts express some soluble factors exclusively in the presence of HSCs. Osteoblasts and hematopoietic cells are closely associated with each other in the bone marrow, suggesting a reciprocal relationship between them to develop the HSC niche. One critical component regulating the niche is stromal-derived factor-1 (SDF-1) and its receptor CXCR4 which regulates stem cell homing and, as we have recently demonstrated, plays a crucial role in facilitating those tumors which metastasize to bone. Osteoblasts produce abundant amounts of SDF-1 and therefore osteoblasts play an important role in metastasis. These findings are discussed in the context of the role of osteoblasts in marrow function in health and disease.

Multicellular spheroids of bone marrow stromal cells: a three-dimensional in vitro culture system for the study of hematopoietic cell migration

Cell fate decisions are governed by a complex interplay between cell-autonomous signals and stimuli from the surrounding tissue. In vivo cells are connected to their neighbors and to the extracellular matrix forming a complex three-dimensional (3-D) microenvironment that is not reproduced in conventional in vitro systems. A large body of evidence indicates that mechanical tension applied to the cytoskeleton controls cell proliferation, differentiation and migration, suggesting that 3-D in vitro culture systems that mimic the in vivo situation would reveal biological subtleties. In hematopoietic tissues, the microenvironment plays a crucial role in stem and progenitor cell survival, differentiation, proliferation, and migration. In adults, hematopoiesis takes place inside the bone marrow cavity where hematopoietic cells are intimately associated with a specialized three 3-D scaffold of stromal cell surfaces and extracellular matrix that comprise specific niches. The relationship between hematopoietic cells and their niches is highly dynamic. Under steady-state conditions, hematopoietic cells migrate within the marrow cavity and circulate in the bloodstream. The mechanisms underlying hematopoietic stem/progenitor cell homing and mobilization have been studied in animal models, since conventional two-dimensional (2-D) bone marrow cell cultures do not reproduce the complex 3-D environment. In this review, we will highlight some of the mechanisms controlling hematopoietic cell migration and 3-D culture systems.

Myeloablative Treatment Supported by Autologous Stem Cell Infusion with Neuroblastoma

Bcr-abl antisense oligodeoxynucleotides (AS-ODNs) have provided evidence of an antileukemia effect when tested in vitro against Philadelphia-positive cells. In order to investigate the efficacy of AS-ODNs as purging agents in chronic myeloid leukemia (CML) patients, K562 cells, a human CML cell line, were treated in vitro with various types of AS-ODNs and interferon-alpha. Cells were treated in vitro for 0 and 36 hr with 40 microgram/mL of AS-ODNs, respectively, and incubated at 37 degrees C for 36 hr. Cytotoxic effects were measured by counting the number of viable cells as well as by MTT test. Clonogenic activities were evaluated by methylcellulose culture for 2 weeks. The effects of purging agents on the rearrangement of bcrabl gene were evaluated by RT-PCR. AS-ODNs inhibited the proliferation of K562 cells with time in cell count assay and MTT test. AS-ODNs were superior to INF-alpha in inhibiting clonogenic activity (recovery rate; 26.3% vs 64.0%). After incubation with bcr-abl AS-ODNs primers and mRNA isolated from K562 cells, positive bands were abolished, especially of b3a2 type and phosphorothioate type. Our results suggest that AS-ODNs mediated purging may be one of the efficient methods and that autograft may be an alternative treatment for allograft in high-risk group patients of CML if they do not have a stem cell donor.

Hemorrhagic Cystitis Following Allogeneic Hematopoietic Cell Transplantation

We conducted a retrospective study to investigate the incidence, risk factors, and clinical features of hemorrhagic cystitis (HC) following allogeneic hematopoietic cell transplantation (allo-HCT). Adult patients who developed HC after allo-HCT were identified from the HCT database of the Asan Medical Center and their medical records were reviewed. From December 1993 to August 2001, a total of 210 adult patients underwent allo-HCT. Fifty-one patients developed HC with a cumulative incidence of 25.7%. The median onset of HC was post-transplant day 24 (range, -2 to 474), and the median duration was 31 days (range, 8 to 369). Significant risk factors for HC by univariate analysis included diagnosis of chronic myelogenous leukemia (p=0.028), unrelated HCT (p=0.029), grade III-IV acute graft-versus-host disease (GVHD) (p<0.001), extensive chronic GVHD (p=0.001), and positive cytomegalovirus antigenemia between post transplant days 31 and 60 (p=0.031). Multivariate analysis showed that grade III-IV acute GVHD was the most important risk factor for the occurrence of HC after allo-HCT (odds ratio, 3.38; 95% CI, 1.36-8.39). Late-onset HC, which occurred beyond 3 weeks after allo-HCT, was more frequently associated with GVHD than earlyonset HC (p=0.007). Our data suggest that a portion of late-onset HC might be a manifestation of GVHD.

Características de las células primordiales germinales murinas y su relación con la hemopoyesis / Characteristics of murine primordial germ cells and their relation with hemopoiesis

Las células germinales primordiales (PGC) son una población de células positivas a la fosfatasa al- calina, que se suelen observar en embriones de 7.5 dias post coitum (dpc) y que migran luego por varios tejidos hasta alojarse en las gonadas. La hematopoyesis es un complejo sistema en el cual las células estaminales hemopoyéticas (HSC) se desarrollan a partir de una simple célula multipotente. Las PGC y HSC están reguladas por un conjunto de factores de crecimiento que controlan la proliferación y diferenciación de los mismos. El factor inhibidor leucémico (LIF) es una citoquina que regula la diferenciación y el fenotipo totipotencial de las PGC como también la capacidad proliferativa de las HSC. Recientemente otros factores de crecimiento: factor de células estaminales (SCF), factor macrofágico (MGF) y forskolin (FRSK) han sido propuestos como posibles reguladores de estos progenitores in vivo e in vitro La inducción a la hemopoyesis de células germinales embrionarias primitivas indica que las células germinales poseen la potencialidad de diferenciarse en el sistema hemopoyético. La coincidente presencia en la región donde la hemopoyesis temprana se establece, para PGC y HSC y el requerimiento de los mismos factores de crecimiento, apoyan la hipótesis que las PGC pueden ser consideradas como células iniciadoras de la hemopoyesis

Cell cycling status of human cord blood CD34+ cells during ex vivo expansion is related to the level of very late antigen expression

Very late antigen-4 (VLA-4), which binds to the extracellular matrix protein fibronectin, is an integrin molecule known to be modulated during mobilization of CD34+ cells, and to be involved in signaling the mobilization stimuli. On the hypothesis that cell cycling status might be different depending on the level of VLA-4 expression, we investigated the DNA contents of human cord blood CD34+ cells during ex vivo expansion by recombinant human thrombopoietin and flt3-ligand with simultaneous measurement of surface VLA-4 at the 1st and 4th week. During this ex vivo expansion, expression of VLA-4 increased and almost all cells became VLA-4+ until the 4th day of culture. Expression of VLA-4 was maintained in the major population of the cultured cells until the 4th week. The cells in S/G2/M phase were greater in number in VLA-4 high fraction than in VLA-4 low fraction (n=4, p<.001). Furthermore, the fraction of cells in S/G2/M phase increased as the expression of VLA-4 became higher. These results suggest that cord blood CD34+ cells expressing high levels of VLA-4 have more proliferative activities.

The hematopoietic stroma

All blood cells are derived from a small common pool of totipotent cells, called hematopoietic stem cells. The process is strictly regulated by the hematopoietic microenvironment, which includes stromal cells, extracellular matrix molecules and soluble regulatory factors. Several experimental in vitro assays have been developed for the study of hematopoietic differentiation, and have provided valuable information on the stroma, which includes, among other cell types, macrophages, fibroblasts, adipocytes, and endothelial cells. The composition, ontogeny, and function in physiological as well as pathological conditions of stroma are discussed

Biología de las células totipotenciales hematopoyéticas / Biology of hemopoietic stem cells

Todas las células que comprenden el sistema hematopoyético son derivadas de un precursor común, la célula totipotencial hematopoyética (CTH), la cual por procesos de proliferación y diferenciación da lugar a las células maduras que se localiza en la sangre y órganos linfohematopoyéticos. Para que se lleven a cabo los procesos de proliferación, supervivencia, apoptosis,inhibición y diferenciación desde las CTH hasta las células maduras funcionales, se requiere de la participación de proteínas denominadas colectivamente citocinas, las cuales promueven y regulan una o varias funciones celulares, e intervienen en una o varías etapas de diferenciación de las CTH. Por el empleo de diferentes técnicas de cultivo, se concluyó que el estroma de la médula ósea: fibroblastos, células endoteliales y adipocitos, tiene un papel importante. La participación de esta células radica en la producción de citocinas, así como en proveer de un soporte sobre el cual se asientan las CTH. Aunque podría parecer que las citocinas son los factores fundamentales para regular los procesos mencionados de las células hematopoyéticas, se han propuesto dos hipótesis principales para explicar cómo se lleva a cabo la hematopoyesis: el modelo determinístico y el modelo estocástico. Ambos modelos aportan pruebas para apoyar sus postulados; sin embargo, a la fecha decidir cuál modelo es el acertado es todavía materia de controversia. Aunque el estudio de las CTH plantea muchas preguntas de orden básico, en muchos laboratorios en el mundo se han comenzado a indagar sobre la aplicación de las CTH en terapia humana: su uso en transplantes, sustituyendo el trasplante de médula ósea completa y, aún en etapas experimentales, el empleado de las CTH para insertar genes que pudieran ser de importancia terapéutica en enfermedades deficitarias o incluso en el tratamiento contra el cáncer

Análisis de progenitores hemopoyéticos en muestras de medula ósea y de sangre periférica en periodos variables de criopreservación / Analysis of hemopoietic progenitor cells in bone marrow and peripheral blood samples which have undergone different periods of cryopreservation

Con el objetivo de evaluar, en función del tiempo, los efectos de la criopreservación sobre los progenitores hematopoyéticos, se estudiaron muestras de médula ósea (MO) y células progenitoras de sangre periférica (SCP) de pacientes a transplante autólogo. Se midió la viabilidad celular y utilizando cultivos de progenitores CFU-GM y BFU-E, el poder clonogénico de las mismas y para evaluar si el estroma medular estaba afectado, se utilizó el cultivo a largo térmico (CALT). De los 23 pacientes estudiados, 5 tenían LMA, 7 MM, 6 LNH, 3 LLA y 2 LH. De estos recibieron transplante de MO autóloga 9 y 14 de SCP. El tiempo de congelación, previo al transplante, varió entre 24 y 33 días, mientras que los cultivos fueron efectuados entre 16 y 40 meses posteriores a la congelación. El desarrollo in vitro de colonias fue positivo en el 40 por ciento de las muestras de LMA y MM, en cambio, en el resto de las muestras, tal desarrollo se observó en casi el 100 por ciento. En las enfermedades linfoides hubo buena correlación entre las células CD33+ y el número de colonias desarrolladas in vitro, no así en LMA y MM. Esto hizo suponer que la enfermedad previa fuese la causante del bajo desarrollo in vitro. En los CALT la capa adherente tuvo su mejor desarrollo con células provenientes de MO, en cambio con las de SPC solamente se observaron macrófagos y fibroblastos. Por lo tanto se desprende que la eficiencia de la criopreservación puede ser medida empleando cultivos de progenitores CFU-GM y BFU-E y que el período que las muestras permanecen congeladas no afecta la potencialidad clonogénica de las mismas.

Aplicaciones clínicas de la citometría de flujo / Clinical utility of flow cytometry

Se analiza la utilidad clínica de la Cotometría de Flujo en el diagnóstico, evolución y pronóstico de diferentes patologías. Se analiza una breve descripción del aparato y sus fundamentos técnicos. Se analizan los usos más frecuentes, principalmente en pacientes VIH/SIDA, otras inmunodeficiencias y en el estudio de leucemias. Finalmente se analizan otras líneas de aplicación del citómetro de flujo en diferentes estados de investigación y estandarización

Ex vivo generation of functional dendritic cells from mobilized CD34+ hematopoietic stem cells

The ability to generate dendritic cells (DCs) in sizeable numbers has enormous implications for the development of clinically-effective antigen presentation procedures for cancer immunotherapy. We evaluated the generation of immunostimulatory DCs from peripheral blood CD34+ cells collected from healthy donors. CD34+ cells purified from leukapheresis product were seeded at 1 x 10(4) cells/mL in complete medium supplemented with GM-CSF, TNF alpha, IL-4, c-kit ligand, and flt3 ligand (FL). By day 14 of culture in the presence of GM-CSF + TNF alpha, the total cell number increased by 23.4 +/- 5.4-fold compared to the starting number of CD34+ cells. When the c-kit and FL were added to GM-CSF and TNF alpha, the cell number increased by 109.8 +/- 11.2-fold without affecting the immunophenotype of recovered cells. Flow cytometric analysis indicated that cells with the markers of mature dendritic cells, i.e., CD1a +CD14 -HLA-DR+, and CD80+CD86+HLA-DR+, constituted 49.0% +/- 7.5%, and 38.9% +/- 6.5%, respectively. This pattern of expression of surface antigen was unchanged whether the c-kit ligand and/or FL was added. The irradiated CD1a+HLA-DR+ cells recovered from in vitro cultures elicit a vigorous proliferation of allogeneic peripheral blood T-cells, irrespective of cytokine combinations. These findings provide advantageous tools for the large-scale generation of DCs that are potentially usable for clinical protocols of immunotherapy or vaccination in patients undergoing cancer treatment.

Storage of haemopoietic stem cells for autologous bone marrow transplantation.

For reinfusing autologous bone marrow cells after high-dose chemotherapy and/or radiotherapy it is necessary that an effective technique for their storage is available. The traditional method uses 10% dimethyl sulphoxide as cryoprotectant, a rate-controlled computerized freezer programmed to cool the cells at a constant rate of 1 degrees C per minute and liquid nitrogen as the storage system. The method is time-consuming, expensive and requires technical expertise. Moreover, it is often associated with varying levels of clinical toxicity following infusion of the preserved cells. Processing the harvest to reduce the initial volume and the mature cells has been shown to be beneficial in reducing the volume of the cryoprotectant and the incidence of toxicity. An alternative, cost-effective method using a cryoprotectant mixture of 5% dimethyl sulphoxide, 6% hydroxyethyl starch and 4% albumin has been found to be effective even when the cells are stored at -80 degrees C without rate-controlled freezing. However, its efficacy needs to be evaluated for extended periods. The current use of purging and cell sorting methods seems to be promising.