Hemic and Lymphatic Diseases Commons^™

Reduced Intensity Conditioning For Acute Myeloid Leukemia Using Melphalan- Vs Busulfan-Based Regimens: A Cibmtr Report, Zheng Zhou, Rajneesh Nath, Jan Cerny, Hai-Lin Wang, Mei-Jie Zhang, Hisham Abdel-Azim, Vaibhav Agrawal, Gulrayz Ahmed, A Samer Al-Homsi, Mahmoud Aljurf, Hassan B Alkhateeb, Amer Assal, Ulrike Bacher, Ashish Bajel, Qaiser Bashir, Minocher Battiwalla, Vijaya Raj Bhatt, Michael Byrne, Jean-Yves Cahn, Mitchell Cairo, Hannah Choe, Edward Copelan, Corey Cutler, Moussab B Damlaj, Zachariah Defilipp, Marcos De Lima, Miguel Angel Diaz, Nosha Farhadfar, James Foran, César O Freytes, Aaron T Gerds, Usama Gergis, Michael R Grunwald, Zartash Gul, Mehdi Hamadani, Shahrukh Hashmi, Mark Hertzberg, Gerhard C Hildebrandt, Nasheed Hossain, Yoshihiro Inamoto, Luis Isola, Tania Jain, Rammurti T Kamble, Muhammad Waqas Khan, Mohamed A Kharfan-Dabaja, Partow Kebriaei, Natasha Kekre, Nandita Khera, Hillard M Lazarus, Jane L Liesveld, Mark Litzow, Hongtao Liu, David I Marks, Rodrigo Martino, Vikram Mathews, Asmita Mishra, Hemant S Murthy, Arnon Nagler, Ryotaro Nakamura, Sunita Nathan, Taiga Nishihori, Rebecca Olin, Richard F Olsson, Neil Palmisiano, Sagar S Patel, Mrinal M Patnaik, Attaphol Pawarode, Miguel-Angel Perales, Ioannis Politikos, Uday Popat, David Rizzieri, Brenda M Sandmaier, Bipin N Savani, Sachiko Seo, Nirav N Shah, Geoffrey L Uy, David Valcárcel, Leo F Verdonck, Edmund K Waller, Youjin Wang, Daniel Weisdorf, Baldeep Wirk, Eric Wong, Jean A Yared, Wael Saber

Faculty, Staff and Students Publications

There is a lack of large comparative study on the outcomes of reduced intensity conditioning (RIC) in acute myeloid leukemia (AML) transplantation using fludarabine/busulfan (FB) and fludarabine/melphalan (FM) regimens. Adult AML patients from Center for International Blood and Marrow Transplant Research who received first RIC allo-transplant between 2001 and 2015 were studied. Patients were excluded if they received cord blood or identical twin transplant, total body irradiation in conditioning, or graft-versus-host disease (GVHD) prophylaxis with in vitro T-cell depletion. Primary outcome was overall survival (OS), secondary end points were leukemia-free survival (LFS), nonrelapse mortality (NRM), relapse, and GVHD. Multivariate survival …

Integrating Geriatric Assessment And Genetic Profiling To Personalize Therapy Selection In Older Adults With Acute Myeloid, Vijaya R. Bhatt

Theses & Dissertations

Integrating geriatric assessment for patient profiling and genetic profiling of leukemic cells represents an innovative approach to personalize therapy selection in older adults with acute myeloid leukemia (AML). We report results of a pre-planned interim analysis of a pragmatic phase II trial that utilized this strategy to personalize therapy. Patients ≥60 years with a new diagnosis of AML underwent geriatric assessment prior to initiation of treatment. Geriatric assessment of physical function, cognitive function and comorbidity burden were used to determine fitness for chemotherapy. Patients with good or intermediate-risk AML received intensive chemotherapy such as anthracycline and cytarabine (7+3) if determined …

Ubiquitination Of The Dna-Damage Checkpoint Kinase Chk1 By Traf4 Is Required For Chk1 Activation, Xinfang Yu, Wei Li, Haidan Liu, Qipan Deng, Xu Wang, Hui Hu, Zijun Y Xu-Monette, Wei Xiong, Zhongxin Lu, Ken H Young, Wei Wang, Yong Li

Faculty, Staff and Students Publications

BACKGROUND: Aberrant activation of DNA damage response (DDR) is a major cause of chemoresistance in colorectal cancer (CRC). CHK1 is upregulated in CRC and contributes to therapeutic resistance. We investigated the upstream signaling pathways governing CHK1 activation in CRC.

METHODS: We identified CHK1-binding proteins by mass spectrometry analysis. We analyzed the biologic consequences of knockout or overexpression of TRAF4 using immunoblotting, immunoprecipitation, and immunofluorescence. CHK1 and TRAF4 ubiquitination was studied in vitro and in vivo. We tested the functions of TRAF4 in CHK1 phosphorylation and CRC chemoresistance by measuring cell viability and proliferation, anchorage-dependent and -independent cell growth, and mouse …

An In Vivo Genome-Wide Crispr Screen Identifies The Rna-Binding Protein Staufen2 As A Key Regulator Of Myeloid Leukemia, Jeevisha Bajaj, Michael Hamilton, Yutaka Shima, Kendall Chambers, Kyle Spinler, Eric L Van Nostrand, Brian A Yee, Steven M Blue, Michael Chen, David Rizzeri, Charles Chuah, Vivian G Oehler, H Elizabeth Broome, Roman Sasik, James Scott-Browne, Anjana Rao, Gene W Yeo, Tannishtha Reya

Faculty, Staff and Students Publications

Aggressive myeloid leukemias such as blast crisis chronic myeloid leukemia and acute myeloid leukemia remain highly lethal. Here we report a genome-wide in vivo CRISPR screen to identify new dependencies in this disease. Among these, RNA-binding proteins (RBPs) in general, and the double-stranded RBP Staufen2 (Stau2) in particular, emerged as critical regulators of myeloid leukemia. In a newly developed knockout mouse, loss of Stau2 led to a profound decrease in leukemia growth and improved survival in mouse models of the disease. Further, Stau2 was required for growth of primary human blast crisis chronic myeloid leukemia and acute myeloid leukemia. Finally, …

Acute Lymphoblastic Leukemia Presenting Initially As Spinal Cord Compression: When Chemotherapy Alone Is Enough, Albert Jang, Kallie N Kram, Scott N Berger, Mahmoud R Gaballa, Lee B Lu, David R Dunaway, Courtney N Miller-Chism

Faculty, Staff and Students Publications

Spinal cord compression (SCC) is a rare initial presentation and complication of acute lymphoblastic leukemia (ALL) with nearly all reported cases occurring in the pediatric population. We report a 38-year-old previously healthy man who presented with acute on chronic lower back pain, gait instability, urinary retention, and severe thrombocytopenia. Radiologic examination revealed two soft tissue masses of the thoracic spine associated with compression fractures causing spinal canal narrowing and cord compression. Bone marrow biopsy confirmed the diagnosis of ALL. Immediate initiation of high-dose corticosteroids and systemic chemotherapy resolved the patient's symptoms without radiation therapy or surgical intervention. After two courses …

The Longitudinal Parallel Process Analysis Of Biomarkers Of Oxidative Stress, Symptom Clusters, And Cognitive Function In Children With Leukemia, Mary C Hooke, Daniel Hatch, Marilyn J Hockenberry, Susan Whitman, Ida Moore, David Montgomery, Kari Marano, Pauline Mitby, Michael E Scheurer, Olga Taylor, Wei Pan

Faculty, Staff and Students Publications

Background: During treatment for acute lymphoblastic leukemia (ALL), children report co-occurring symptoms of fatigue, sleep disturbance, pain, nausea, and depression as a symptom cluster. Central nervous system–directed ALL therapies also put children at risk for cognitive impairments. Cancer therapies can cause an increase in oxidative stress, which may contribute to treatment-related symptoms. This study examined the longitudinal relationships between biomarkers of oxidative stress in the cerebrospinal fluid, the Childhood Cancer Symptom Cluster–Leukemia (CCSC-L), and cognition, in children over the first year of ALL treatment. Methods: Glutathione (GSH) biomarkers of oxidative stress were measured in cerebrospinal fluid collected during treatment lumbar …

Lbrutinib (Lmbruvica™) For Treatment Of Mantle Cell Lymphoma, Brittany Crowe, Joy Hoffman, Hannah Stewart, Alison Steinbrunner, Mark E. Olah

Pharmacy and Wellness Review

Mantle cell lymphoma (MCL) is a rare and moderately aggressive form of non-Hodgkin's lymphoma (NHL) that predominantly presents at an advanced stage in older males. Patients often present with multiple involvement in the lymph nodes, blood, spleen, bone marrow and gastrointestinal tract (GIT). Some patients may be asymptomatic in early stages or present with an incurable, indolent (slow progressing) form, while other patients display rapid growth of more aggressive lymphomas. Overall survival for patients diagnosed with MCL is four to five years and treatment should be initiated in those who are symptomatic. Mantle cell lymphoma responds well to first-line treatment, …

Clinical Pharmacology Of Tisagenlecleucel In B-Cell Acute Lymphoblastic Leukemia., Karen Thudium Mueller, Edward Waldron, Stephan A. Grupp, John E. Levine, Theodore W. Laetsch, Michael A. Pulsipher, Michael W. Boyer, Keith August, Jason Hamilton, Rakesh Awasthi, Andrew M. Stein, Denise Sickert, Abhijit Chakraborty, Bruce L. Levine, Carl H. June, Lori Tomassian, Sweta S. Shah, Mimi Leung, Tetiana Taran, Patricia A. Wood, Shannon L. Maude

Manuscripts, Articles, Book Chapters and Other Papers

PURPOSE: Tisagenlecleucel is an anti-CD19 chimeric antigen receptor (CAR19) T-cell therapy approved for the treatment of children and young adults with relapsed/refractory (r/r) B-cell acute lymphoblastic leukemia (B-ALL).

PATIENTS AND METHODS: We evaluated the cellular kinetics of tisagenlecleucel, the effect of patient factors, humoral immunogenicity, and manufacturing attributes on its kinetics, and exposure-response analysis for efficacy, safety and pharmacodynamic endpoints in 79 patients across two studies in pediatric B-ALL (ELIANA and ENSIGN).

RESULTS: Using quantitative polymerase chain reaction to quantify levels of tisagenlecleucel transgene, responders (N = 62) had ≈2-fold higher tisagenlecleucel expansion in peripheral blood than nonresponders ( …

The Evaluation Of Mefloquine Drug Repurposing On Acute Myeloid Leukemia, Jessica L. Phan, Bhavuk Garg, Hrishikesh Mehta, Seth Corey

UROP Posters

The aim of this study is to observe cell proliferation, cell viability, apoptosis, and autophagy on acute myeloid leukemia (AML) cell lines, NB4 and U937, with the drug repurposing of mefloquine (MQ). Methods such as the 3-(4,5-Dimethylthiazol-2-Yl)-2,5-Diphenyltetrazolium Bromide (MTT) assay and trypan blue staining have shown a decrease in live cells with high concentrations of mefloquine. Using their average perspective IC50 values of MQ concentration, Western blotting was applied by means of apoptosis and autophagy markers to determine if the induction of apoptosis and inhibition of autophagy was present in MQ-treated AML cells. The experiment will be continued with more …

Robustness Of A Newly Proposed Risk Schema For Lymphatic Dissemination In Endometrioid Endometrial Cancer, Danielle M. Greer, Jessica J.F. Kram, Callie M. Cox Bauer, Scott A. Kamelle

Journal of Patient-Centered Research and Reviews

Background: Surgical management for endometrioid endometrial cancer (EEC) includes complete lymph node dissection for all patients at risk of lymphatic dissemination. The standard risk schema, defined by Mayo Clinic, identifies low-risk patients as those with grade 1/2 EEC, myometrial invasion (MI) ≤ 50%, and tumor diameter (TD) ≤ 2 cm. We recently proposed (and published) a risk schema containing modified forms of grade, MI and TD that suggests a significant decrease in false-negative rate and need for lymphadenectomy in low-risk women.

Purpose: Evaluate robustness of our proposed schema for lymphatic dissemination risk stratification in a subsequent EEC patient cohort.

Methods: …

Dnmt3a Haploinsufficiency Provokes Hematologic Malignancy Of B-Lymphoid, T-Lymphoid, And Myeloid Lineage In Mice, Garland Michael Upchurch

Theses & Dissertations

DNA methyltransferase 3A (DNMT3A) is a master epigenetic regulator of benign and malignant hematopoiesis. To dissect the biological consequences of homozygous and heterozygous Dnmt3a inactivation in malignant hematopoiesis, we generated Dnmt3a homozygous null (Dnmt3a^Δ/Δ) and Dnmt3a heterozygous (Dnmt3a^+/–) mice and compared the presentations of hematologic malignancies between cohorts. Bi-allelic inactivation of Dnmt3a results in the presentation of mature lymphoid neoplasms resembling chronic lymphocytic leukemia (CLL; B220⁺CD19⁺CD5⁺; 88% penetrance (37/42)) and CD8+ peripheral T-cell lymphoma (PTCL; TCRβ⁺CD3⁺CD8⁺CD4^—; 40% penetrance (17/42)). …

Dox Inducible Idh2 R140q Expression In Stem Cells Results In Cell Death, Opposite Of Cancerous Overgrowth, Reuben Hogan

Undergraduate Research Symposium Posters

Mutations in isocitrate dehydrogenase (IDH) 1 or 2 are found in about 23% of acute myeloid leukemia (AML) samples and about 90% of gliomas. Mutations result in neomorphic function of the IDH enzyme that yields the novel molecule 2-hydroxyglutarate (2HG) instead of alpha-ketoglutarate (aKG). 2HG is known to be associated with hypermethylation of DNA and histones, a phenotype seen in AML. Our lab intends to study the mechanism by which hypermethylation is achieved and how this mechanism relates to the onset of cancer. In this experiment, we utilized a line of H9 stem cells which we had developed. These cells …

Mir-155 Expression And Correlation With Clinical Outcome In Pediatric Aml: A Report From Children's Oncology Group., Ranjani Ramamurthy, Maya Hughes, Valerie Morris, Hamid Bolouri, Robert B. Gerbing, Yi-Cheng Wang, Michael R. Loken, Susana C. Raimondi, Betsy A. Hirsch, A S. Gamis, Vivian G. Oehler, Todd A. Alonzo, Soheil Meshinchi

Manuscripts, Articles, Book Chapters and Other Papers

BACKGROUND: Aberrant expression of microRNA-155 (miR-155) has been implicated in acute myeloid leukemia (AML) and associated with clinical outcome.

PROCEDURE: We evaluated miR-155 expression in 198 children with normal karyotype AML (NK-AML) enrolled in Children's Oncology Group (COG) AML trial AAML0531 and correlated miR-155 expression levels with disease characteristics and clinical outcome. Patients were divided into quartiles (Q1-Q4) based on miR-155 expression level, and disease characteristics were then evaluated and correlated with miR-155 expression.

RESULTS: MiR-155 expression varied over 4-log10-fold range relative to its expression in normal marrow with a median expression level of 0.825 (range 0.043-25.630) for the entire …

Erratum To: High Expression Of Myocyte Enhancer Factor 2c (Mef2c) Is Associated With Adverse-Risk Features And Poor Outcome In Pediatric Acute Myeloid Leukemia: A Report From The Children's Oncology Group., George S. Laszlo, Todd A. Alonzo, Chelsea J. Gudgeon, Kimberly H. Harrington, Alex Kentsis, Robert B. Gerbing, Yi-Cheng Wang, Rhonda E. Ries, Susana C. Raimondi, Betsy A. Hirsch, A S. Gamis, Soheil Meshinchi, Roland B. Walter

Manuscripts, Articles, Book Chapters and Other Papers

No abstract provided.

Shorter Remission Telomere Length Predicts Delayed Neutrophil Recovery After Acute Myeloid Leukemia Therapy: A Report From The Children's Oncology Group., Robert B. Gerbing, Todd A. Alonzo, Lillian Sung, Alan S. Gamis, Soheil Meshinchi, Sharon E. Plon, Alison A. Bertuch, Maria M. Gramatges

Manuscripts, Articles, Book Chapters and Other Papers

Purpose Suboptimal outcomes for children with acute myeloid leukemia (AML) necessitate maximally intensive therapy. Consequently, serious adverse events, such as prolonged periods of profound myelosuppression, contribute to AML treatment-related mortality. Telomeres, the repetitive DNA-protein structures at chromosome ends, influence cellular replicative capacity in that critically short telomeres can induce cell senescence or apoptosis. Our objective was to evaluate the impact of telomere length on duration of post-therapy neutropenia in a pediatric AML cohort. Patients and Methods Patients were diagnosed with de novo AML, enrolled in Children's Oncology Group study AAML0531, and included those with (n = 53) and without (n …

Association Between Prolonged Neutropenia And Reduced Relapse Risk In Pediatric Aml: A Report From The Children's Oncology Group., Lillian Sung, Richard Aplenc, Todd A. Alonzo, Robert B. Gerbing, Yi-Cheng Wang, Soheil Meshinchi, A S. Gamis

Manuscripts, Articles, Book Chapters and Other Papers

Objective was to describe the relationship between the number of sterile site infections and duration of neutropenia during the first four cycles of chemotherapy and the risk of recurrence and overall survival in children with newly diagnosed acute myeloid leukemia (AML). AAML0531 was a Children's Oncology Group randomized phase 3 clinical trial that included 1022 children with de novo AML. For this analysis, we focused on non-Down syndrome favorable and standard risk patients who completed at least 4 cycles of chemotherapy without recurrence or withdrawal during protocol therapy. Those receiving hematopoietic stem cell transplantation in first remission were excluded. Five …

Scanned Ion Beam Therapy For Thoracic Tumors, John Gordon Eley

Dissertations and Theses (Open Access)

Although frequently cured of Hodgkin lymphoma, adolescents and young adults can develop radiation induced second cancers. These patients could potentially benefit from scanned ion radiotherapy yet likely would require motion mitigation strategies. In theory, four-dimensional (4D) optimization of ion beam fields for individual motion states of respiration can enable superior sparing of healthy tissue near moving targets, compared to other motion mitigation strategies. Furthermore, carbon-ion therapy can sometimes provide greater relative biological effectiveness (RBE) for cell sterilization in a target but nearly equivalent RBE in tissue upstream of the target, compared to proton therapy. Thus, we expected that for some …

Acute Myeloid Leukaemia In Children: Experience At A Tertiary Care Facility Of Pakistan, Zehra Fadoo, Naureen Mushtaq, Saima Alvi, Muhammad Ali

Department of Paediatrics and Child Health

Objective: To document the demographics and outcome of children with Acute Myeloid Leukemia (AML) treated at a tertiary care facility of Pakistan.

Methods: A retrospective study was conducted at Aga Khan University on children (less than 15 years) diagnosed to have AML between January 2000 to May 2007.Total 40 cases were diagnosed out of which 37 charts were available for review.

Results: The average age of presentation was 8.5±4.5 years and 75% were males. The most common presenting feature was fever in 83% followed by bleeding in 41% and pallor in 39%. Initial WBC of > 100,000 was seen in 19% …

P27kip1 And P130 Cooperate To Regulate Hematopoietic Cell Proliferation In Vivo, Inês Soeiro, Azim Mohamedali, Hanna M. Romanska, Nicholas C. Lea, Emma S. Child, Janet Glassford, Stephen J. Orr, Claudia Roberts, Kikkeri N. Naresh, El-Nasir Lalani, David J. Mann, Roger J. Watson, N. Shaun B. Thomas, Eric W. -F. Lam

Department of Pathology and Laboratory Medicine

To investigate the potential functional cooperation between p27^Kip1 and p130 in vivo, we generated mice deficient for both p27^Kip1 and p130. In p27^Kip1−/−;p130^−/− mice, the cellularity of the spleens but not the thymi is significantly increased compared with that of their p27^Kip1−/− counterparts, affecting the lymphoid, erythroid, and myeloid compartments. In vivo cell proliferation is significantly augmented in the B and T cells, monocytes, macrophages, and erythroid progenitors in the spleens of p27^Kip1−/−; p130^−/− animals. Immunoprecipitation and immunodepletion studies indicate that p130 can compensate for the absence …

Small B Cell Non-Hodgkins Lymphoma In Pakistan, Kanwal Aftab, Yasmin Bhurgri, Shahid Pervez

Department of Pathology and Laboratory Medicine

Objective: To study the pattern of small B cell lymphomas in Pakistan.

Methods: This descriptive study was carried out at the Aga Khan University Hospital pathology department including 1721 cases of Non-Hodgkins Lymphoma (NHL) diagnosed during a period of five years (1998-2002) and classified according to REAL/WHO classification. The antibodies used included Leukocyte Common Antigen (LCA), Pan B (CD20, CD79a), Pan T (UCHL-1), Bcl 2, Mib 1(Ki 67) and Cyclin D1 (Dako, Denmark).

Results: Out of the 1721 NHL cases, only 140 (8.1%) could be categorized as small B-cell NHL. The study group comprised small lymphocytic lymphoma/chronic lymphocytic leukemia (58 …

Flow Cytometric And Demographic Analysis Of T Cell Acute Lymphoblastic Leukemia In Pakistani Population., M R. Khawaja, S S. Allana, N N. Akbaral, S N. Adil, M. Khurshid, Shahid Pervez

Department of Pathology and Laboratory Medicine

Background: This study was carried out to analyze the proportion of T cell acute lymphoblastic leukemia (TALL) among all acute lymphoblastic leukemia (ALL) in Pakistani population and its correlation with the demographic features. Accuracy of cell surface markers used in flow cytometric analysis of the leukemic cells was also determined.

Methods: Data of 209 consecutive cases of acute lymphoblastic leukemia (ALL) presenting between July 1995 and July 2003 was analyzed. Flow cytometry was performed on all ALL cases using the standard protocols. TALL markers included CD3, CD5 and CD7.

Results: Proportion of TALL among known ALL Pakistani patients was 17.22%. …

Spectrum Of Hodgkin's Disease In Children And Adults: Impact Of Combined Morphologic And Phenotypic Approach For Exclusion Of Look-Alikes, Tanya Siddiqui, Shahid Pervez

Department of Pathology and Laboratory Medicine

Objective:

To determine the prevalence of Hodgkin’s disease (HD) and its various subtypes in children and adults and assess the use of immunohistochemical (IHC) studies in confirming HD cases and excluding its close mimicries/look-alikes.

Material and Methods:

All 265 Hodgkin’s disease cases diagnosed at The Aga Khan University Hospital, Karachi over the last 6 years (July 1991 - July 1997) were included. Of these 219 were diagnosed on routine H&E examination while in the remaining 46 cases, diagnosis was made after a thorough IHC workup. (This group initially included 161 cases labelled as lymphoproliferative disorder with HD as one of …

Immunophenotypic Analysis Of Non-Hodgkin's Lymphoma, Suhail Muzaffar, Shahid Pervez, Farrukh Aijaz, Syed Abdul Aziz, Sheema H. Hasan

Department of Pathology and Laboratory Medicine

One hundred and three cases of Non-Hodgkin’s lymphoma were evaluated immunohistochemically using a panel of monoclonal antibodies which includes leucocyte common antigen (LCA), CD45R (Pan-B marker), L-26 (CD 20-Pan-B marker) and UCHL-1 (Pan-T marker). Of the total 63 cases (61.17%) showed a B-cell phenotype while 40(38.83%) were of T-cell origin. Most B-cell neoplasms belonged to intermediate (79.36%) or high grade (15.87%) according to the international Working Formulation (WF). Most T- cell lymphomas were of either intermediate (52.5%) or high grade (32.5%) neoplasms. Some T-cell neoplasms presented as specific clinicopathological entities like lymphomatoid granulomatosis (2 cases), mycosis fungoides (1 case) and …

Localized Tuberculosis And Myelofibrosis With Myeloid Metaplasia : An Extremely Unusual Presentation, Suhail Muzaffar

Department of Pathology and Laboratory Medicine

Myelofibrosis with myeloid metaplasia (MMM) is usually considered primary agnogenic, however, it may be secondary to various diseases, The association of tuberculosis with MMIM is exceedingly rare, however, the pathogenetic relationship between the two is difficult to define. We present a case report showing simultaneous presentation of localized active tuberculosis and MMM The literature on the subject is also reviewed with special emphasis on pathogenic relation­ship between the two.

Efficient Immortalization Of Luminal Epithelial Cells From Human Mammary Gland By Introduction Of Simian Virus 40 Large Tumor Antigen With A Recombinant Retrovirus, Bartek J, Bartkova J, Kyprianou N, El-Nasir Lalani, Staskova Z, Shearer M, Chang S, Taylor Papadimitriou J

Department of Pathology and Laboratory Medicine

When defined in terms of markers for normal cell lineages, most invasive breast cancer cells correspond to the phenotype of the common luminal epithelial cell found in the terminal ductal lobular units. Luminal epithelial cells cultured from milk, which have limited proliferative potential, have now been immortalized by introducing the gene encoding simian virus 40 large tumor (T) antigen. Infection with a recombinant retrovirus proved to be 50-100 times more efficient than calcium phosphate transfection, and of the 17 cell lines isolated, only 5 passed through a crisis period as characterized by cessation of growth. When characterized by immunohistochemical staining …