Assessment of whole-genome mapping in a well-defined outbreak of Salmonella enterica serotype Saintpaul.

We investigated the use of whole-genome mapping and pulsed-field gel electrophoresis (PFGE) with isolates from an outbreak of Salmonella enterica serotype Saintpaul. PFGE and whole-genome mapping were concordant with 22 of 23 isolates. Whole-genome mapping is a viable alternative tool for the epidemiological analysis of Salmonella food-borne disease investigations.

Proportional mouse model for aerosol infection by influenza.

AIMS: The aim of this study was to demonstrate a prototype tool for measuring infectivity of an aerosolized human pathogen - influenza A/PR/8/34 (H1N1) virus - using a small-animal model in the Controlled Aerosol Test System (CATS). METHODS AND RESULTS: Intranasal inoculation of nonadapted H1N1 virus into C57BL, BALB/c and CD-1 mice caused infection in all three species. Respiratory exposure of CD-1 mice to the aerosolized virus at graduated doses was accomplished in a modified rodent exposure apparatus. Weight change was recorded for 7 days postexposure, and viral populations in lung tissue homogenates were measured post mortem by DNA amplification (qRT-PCR), direct fluorescence and microscopic evaluation of cytopathic effect. Plots of weight change and of PCR cycle threshold vs delivered dose were linear to threshold doses of ~40 TCID(50) and ~12 TCID(50) , respectively. CONCLUSIONS: MID(50) for inspired H1N1 aerosols in CD-1 mice is between 12 and 40 TCID(50) ; proportionality to dose of weight loss and viral populations makes the CD-1 mouse a useful model for measuring infectivity by inhalation. SIGNIFICANCE AND IMPACT OF THE STUDY: In the CATS, this mouse-virus model provides the first quantitative method to evaluate the ability of respiratory protective technologies to attenuate the infectivity of an inspired pathogenic aerosol.

Clinical evaluation of the BioFire® Respiratory Panel 2.1 and detection of SARS-CoV-2.

We evaluated the performance of the BioFire® Respiratory Panel 2.1 (RP2.1) in the detection of SARS CoV-2 in comparison against three other SARS CoV-2 EUA assays. In these studies, the RP2.1 panel had 98 % positive percent agreement (48/49) and 100 % negative percent agreement (49/49). Since 30 % of nasopharyngeal swab specimens have a SARS CoV-2 Ct >30 and thus detection of virus in low titers is clinically relevant, a sample with a high titer was diluted and each 10 fold dilution was tested in triplicate and compared against 6 other EUA approved SARS CoV-2 assays. These data suggested that the BioFire® RP2.1 panel, along with four other SARS CoV-2 assays (Roche cobas, Cepheid Xpert Xpress, BioFire® Defense COVID19, and NECoV19), consistently detected viral RNA at the 10-7 dilution. Overall, these studies suggest that the BioFire® RP2.1 assay can be used to detect acute cases of SARS CoV2 in addition to patients with low viral titer later in disease presentation.

The tat gene of human T-lymphotropic virus type 1 induces mesenchymal tumors in transgenic mice.

Human T-lymphotropic virus type 1 (HTLV-1) is a suspected causative agent of adult T-cell leukemia. One of the viral genes encodes a protein (tat) that not only results in transactivation of viral gene expression but may also regulate the expression of certain cellular genes that are important for cell growth. Transgenic mice that expressed the authentic tat protein under the control of the HTLV-1 long terminal repeat were generated, and cell types that are permissive for the viral promoter and the effects of the tat gene on these cells were studied. Three of eight founder mice with high levels of expression of the transgene in muscle were bred and then analyzed. All developed soft tissue tumors at multiple sites between 13 to 17 weeks of age. This phenotype was transmitted to nine of nine offspring that inherited the tat gene and were available for analysis. The remaining five founders expressed the transgene in the thymus, as well as in muscle. This second group of mice all exhibited extensive thymic depletion and growth retardation; in all of these mice, death occurred between 3 to 6 weeks of age before tumors became macroscopically visible. The tat gene under the control of the HTLV-1 regulatory region showed tissue-specific expression and the tat protein efficiently induced mesenchymal tumors. The data establish tat as an oncogenic protein and HTLV-1 as a transforming virus.

A transgenic mouse model for human neurofibromatosis.

Human T-lymphotropic virus type 1 (HTLV-1) has been associated with the neurologic disorder tropical spastic paraparesis and possibly with multiple sclerosis. The tat gene of HTLV-1 under control of its own long terminal repeat is capable of inducing tumors in transgenic mice. The morphologic and biologic properties of these tumors indicate their close resemblance to human neurofibromatosis (von Recklinghausen's disease), the most common single gene disorder to affect the nervous system. The high spontaneous incidence of this disease, together with the diverse clinical and pathologic features associated with it, suggests that environmental factors may account for some of the observed cases. Multiple tumors developed simultaneously in the transgenic tat mice at approximately 3 months of age, and the phenotype was successfully passed through three generations. The tumors arise from the nerve sheaths of peripheral nerves and are composed of perineural cells and fibroblasts. Tumor cells from these mice adapt easily to propagation in culture and continue to express the tat protein in significant amounts. When transplanted into nude mice, these cultured cells efficiently induce tumors. Evidence of HTLV-1 infection in patients with neural and other soft tissue tumors is needed in order to establish a link between infection by this human retrovirus and von Recklinghausen's disease and other nonlymphoid tumors.

Structural evidence for the authenticity of the human retinoblastoma gene.

The retinoblastoma (Rb) gene is the prototype for a class of recessive human cancer genes in which loss of activity of both normal alleles is thought to be associated with tumorigenesis. Sixteen of 40 retinoblastomas examined with a complementary DNA probe shown to be the Rb gene had identifiable structural changes of the Rb gene including in some cases homozygous internal deletions with corresponding truncated transcripts. An osteosarcoma also had a homozygous internal deletion with a truncated transcript. In addition, possible hot spots for deletion were identified within the Rb genomic locus. Among those tumors with no identifiable structural changes there was either absence of an Rb transcript or abnormal expression of the Rb transcript. Comparison of the structural changes in the tumor cells and fibroblasts of certain patients provided support for Knudson's two-hit hypothesis for the development of retinoblastoma at the molecular level. The ability to detect germline structural deletions in fibroblasts from some patients with bilateral retinoblastoma also indicates that the isolated gene is useful for diagnostic purposes.

Molecular analysis of Francisella tularensis subspecies tularensis and holarctica.

Rapid methods are needed for public health and military applications to specifically identify Francisella tularensis, the causative agent of tularemia in humans. A comparative analysis of the capabilities of multiple technologies was performed using a well-defined set of organisms to determine which approach would provide the most information in the shortest time. High-resolution molecular techniques, including pulsed-field gel electrophoresis, amplified fragment length polymorphism, and ribotyping, provided subspecies level identification within approximately 24 hours after obtaining an isolate, whereas multilocus variable number tandem repeat analysis with 8 or 25 targets provided strain level discrimination within about 12 hours. In contrast, Raman spectroscopy provided species level identification in 10 minutes but could not differentiate between subspecies tularensis and holarctica.

Promoter activity of the proliferating-cell nuclear antigen gene is associated with inducible CRE-binding proteins in interleukin 2-stimulated T lymphocytes.

The proliferating-cell nuclear antigen (PCNA) gene encodes an auxiliary factor of DNA polymerase delta and functions in DNA replication during S phase. It is expressed at much higher levels in proliferating cells than in quiescent cells. We have studied the regulatory role of the 5'-flanking sequence of the murine PCNA gene in interleukin 2 (IL-2)-responsive cloned T cells (L2). Analysis of a set of deletion constructs in transient transfection assays measuring heterologous reporter gene (luciferase) activity demonstrated that the 182-bp 5'-flanking region provides full promoter activity in IL-2-stimulated L2 cells. While many elements contribute to PCNA promoter strength in IL-2-stimulated cells, the largest decrease in activity occurred with deletion of the tandem CRE (cyclic AMP response element) binding sites located at nucleotides -37 to -52. With a gel mobility shift assay, several IL-2-inducible DNA-protein complexes were detected, including CREB (CRE-binding) and ATF1 (activating transcription factor) proteins that are specific for the PCNA-CRE sequence. Methylation interference analysis confirmed specific binding of these proteins to the CRE sites. Mutation at the PCNA-CRE motif abolishes IL-2-inducible binding and reduces substantially PCNA promoter activity. These results indicate that IL-2-stimulated PCNA transcription may be partially mediated by these CRE-binding proteins.

Delayed tumor onset in transgenic mice fed a low-folate diet.

BACKGROUND: Transgenic mice carrying the human T-lymphotropic virus type 1 tax1 (transactivator) gene develop peripheral nerve sheath tumors with well-characterized times of onset and tissue involvement. PURPOSE AND METHODS: To evaluate the effect of dietary folic acid on age at tumor onset and on the concentration of folate in tissues and tumors, we bred heterozygous transgenic mice and systematically assigned their offspring at weaning (within litters) to a 2 x 2 x 2 factorial arrangement. The three variables studied were 1) the tax1 gene (presence or absence), 2) gender (male or female), and 3) dietary level of folic acid (0.11 or 11.34 mumol folic acid per kilogram of controlled amino acid-based diet). Blood and tissues were collected from tumor-bearing transgenic mice (prior to cachexia) and from nontransgenic littermates, matched whenever possible for gender and diet. RESULTS: Transgenic mice fed a diet containing 0.11 mumol of folic acid per kilogram developed tumors significantly later (92.8 +/- 6.4 days) than did those fed a diet containing 11.34 mumol of folic acid per kilogram (71.9 +/- 3.9 days). Folate concentrations in tumors of mice fed the low-folate diet were approximately one third those in tumors of mice fed the higher folate diet. Brain folate concentrations in mice fed the low-folate diet were less than one half those in mice fed the higher folate diet. CONCLUSION: Results show that the onset of spontaneous tumors can be delayed by feeding mice the lowest level of folate adequate to meet nutritional requirements for normal growth. IMPLICATION: Transgenic animal models of human disease offer great potential for evaluating the role of micronutrients in human carcinogenesis.

Liver cancer in transgenic mice carrying the human immunodeficiency virus tat gene.

Patients with the acquired immunodeficiency syndrome are at risk to develop a variety of different cancers. Based on epidemiological data, Kaposi's sarcoma and non-Hodgkin's lymphoma have been clearly associated with infection by the human immunodeficiency virus (HIV). Additional cancers such as basal cell and squamous cell carcinomas, melanoma, and hepatocellular carcinoma have also been reported to be associated with a diagnosis of acquired immunodeficiency syndrome. A direct causal role of HIV has yet to be established for any of these cancers. We now report that transgenic mice carrying the HIV tat gene develop a high incidence of hepatocellular carcinoma after a long latency and that these changes in the liver are likely to be initiated by extrahepatic growth signals from the tat expressing cells in these mice. We predict that as acquired immunodeficiency syndrome patients begin to respond to therapy and show prolonged survival, such "secondary" malignancies induced by HIV will become increasingly prevalent.

Phosphorylation of the EWS IQ domain regulates transcriptional activity of the EWS/ATF1 and EWS/FLI1 fusion proteins.

Specific chromosomal translocations are commonly present in mesenchymal tumors and frequently involve genes encoding transcription factors. The combination of different domains from unrelated genes results in chimeric proteins believed to play a key role in the neoplastic process. The EWS/ATF1 and EWS/FLI1 fusion proteins associated with Clear Cell Sarcoma and Ewing's Sarcoma, respectively, were utilized to study the comparative effect of the EWS component on two different DNA binding partners. A potential regulatory site within the EWS IQ domain at serine266 was identified, and studies were performed to demonstrate that EWS is phosphorylated in cells and phosphorylation of serine266 regulates transcriptional activity. Mutational analysis showed that elimination of phosphorylation significantly reduced DNA binding activity by EMSA and reporter activation in luciferase assays, whereas phosphorylation mimicry resulted in a partial restoration to wild-type levels. Phosphorylation was also observed to mediate cellular compartmentalization. These studies confirm that IQ domain phosphorylation regulates the transcriptional activity of exogenous EWS/ATF1 and EWS/FLI1 and suggests that post-translational modifications may potentiate the neoplastic behavior of fusion proteins in general. Since the IQ domain is incorporated into only a subset of fusion transcripts, these findings may provide insight into the molecular mechanism underlying clinical heterogeneity observed in Ewing's sarcoma.

Inhibition of tumor growth and metastasis of human melanoma by intracellular anti-ATF-1 single chain Fv fragment.

Activating transcription factor-1 (ATF-1) and cAMP-responsive element (CRE)-binding protein (CREB) have been implicated in cAMP and Ca2+-induced transcriptional activation. The expression of the transcription factors CREB and ATF-1 is upregulated in metastatic melanoma cells. However, how overexpression of ATF-1/CREB contributes to the acquisition of the metastatic phenotype remains unclear. Here, the effect of disrupting ATF-1 activity was investigated using intracellular expression of an inhibitory anti-ATF-1 single chain antibody fragment (ScFv). Intracellular expression of ScFv anti-ATF-1 in MeWo melanoma cells caused significant reduction in CRE-dependent promoter activation. In addition, expression of ScFv anti-ATF-1 in melanoma cells suppressed their tumorigenicity and metastatic potential in nude mice. ScFv anti-ATF-1 rendered the melanoma cells susceptible to thapsigargin-induced apoptosis in vitro and caused massive apoptosis in tumors transplanted subcutaneously into nude mice, suggesting that ATF-1 and its associated proteins act as survival factor for human melanoma cells. This is the first report to demonstrate the potential of ScFv anti-ATF-1 as an inhibitor of tumor growth and metastasis of solid tumor in vivo. Oncogene (2000).

Depletion of EBV-infected cells in donor marrow by counterflow elutriation.

Epstein-Barr virus (EBV)-associated posttransplantation lymphoproliferative disease (PTLD) is a well-recognized complication of T cell-depleted (TCD) allogeneic bone marrow transplantation (BMT). Certain methods of TCD, such as counterflow elutriation (CE), have not been associated with an increased incidence of PTLD. Since CE depletes B cells as well as T cells, the hypothesis that CE depletes donor marrow of EBV-infected cells was tested in this study. Marrow samples from 70 donors were assayed by qualitative and semi-quantitative polymerase chain reaction (PCR) amplification to detect EBV DNA in four cellular fractions produced by elutriation: a small cell fraction (F70), two intermediate-sized cell fractions (F110 and F140), and a large cell (hematopoietic precursor-enriched, lymphocyte-depleted) rotor-off (R/O) fraction. The distribution of B cells in elutriation fractions was 21% (F70), 59% (F110), 18% (F140), and 2% (R/O). Qualitatively, the frequency of EBV DNA detected in fractions was 49% (F70), 57% (F110), 73% (F140), and 44% (R/O). The relative concentration of EBV DNA in each fraction was determined by semiquantitative PCR. The mean number of EBV DNA copies per 150,000 cells was 0.57 (F70), 4.6 (F110), 5.7 (F140), and 0.61 (R/O). Relative EBV DNA load in each fraction was calculated by multiplying the mean concentration of EBV DNA per fraction and mean mononuclear cell content in each fraction. The relative distribution of EBV DNA was 0.5, 58, 40, and 1.5% in the F70, F110, F140, and R/O fractions, respectively. No correlation between the amount of EBV in the graft and development of PTLD could be made, because only one of the 70 recipients developed PTLD and this was following autologous hematopoietic recovery. Although these results demonstrate that the majority of EBV-infected cells in marrow are separated from the TCD graft by counterflow elutriation, further studies are required to differentiate the role of this phenomenon from that of other potential factors, such as the amount of T cell depletion and recovery of EBV immunity in the pathogenesis of PTLD after BMT.

Delayed tumor onset in transgenic mice fed an amino acid-based diet supplemented with red wine solids.

Increased consumption of vegetable foods (cereals, legumes, fruits) and some beverages (tea, cider, wine) is associated with reduced risk of cancer. Polyphenols in these foods and beverages are thought to be responsible, based on data from in vitro assays and from in vivo studies that used animals pretreated with carcinogen and given tea or polyphenol-spiked water to drink. We tested the hypothesis that dehydrated-dealcoholized red wine (wine solids), when consumed as part of a precisely defined complete diet, would delay tumor onset in transgenic mice that spontaneously develop externally visible tumors without carcinogen pretreatment. Sibling transgenic mice were weaned onto an amino acid-based diet alone or supplemented with red wine solids. Mice were examined daily; the age at which a first tumor appeared was recorded as the age of tumor onset. The concentration of the major polyphenol of red wine (catechin) in blood serum was also measured at the end of the study. The supplemented diet was fed continuously for three generations to ensure that it supported normal growth and reproduction. We discovered that the wine solid supplement delayed tumor onset, that intact catechin was absorbed, and that the supplemented diet supported normal growth and reproduction for three generations. Also, our simple experimental protocol offers an alternate and/or complementary way to identify foods, beverages, and their constituents that delay tumor onset and to investigate possible mechanisms involved.

99mTc-labeled divalent and tetravalent CC49 single-chain Fv's: novel imaging agents for rapid in vivo localization of human colon carcinoma.

UNLABELLED: Radioimmunopharmaceutical agents enabling rapid high-resolution imaging, high tumor-to-background ratios, and minimal immunogenicity are being sought for cancer diagnosis and imaging. Genetic engineering techniques have allowed the design of single-chain Fv's (scFv's) of monoclonal antibodies (mAbs) recognizing tumor-associated antigens. These scFv's show good tumor targeting and biodistribution properties in vivo, indicating their potential as imaging agents when labeled with a suitable radionuclide. METHODS: Divalent (sc(Fv)(2)) and tetravalent ([sc(Fv)(2)](2)) scFv's of mAb CC49 were evaluated for radioimmunolocalization of LS-174T colon carcinoma xenografts in athymic mice. scFv's were radiolabeled with (99m)Tc by way of the bifunctional chelator succinimidyl-6-hydrazinonicotinate hydrochloride using tricine as the transchelator. The immunoreactivity and in vitro stability of the scFv's were analyzed after radiolabeling. Biodistribution and pharmacokinetic studies were performed to determine the tumor-targeting potential of the radiolabeled scFv's. Whole-mouse autoradiography illustrated the possible application of these (99m)Tc-labeled multivalent scFv's for imaging. RESULTS: The radiolabeling procedure gave > or =95% radiometal incorporation, with a specific activity of >74 MBq/mg scFv. In solid-phase radioimmunoassay, both sc(Fv)(2) and [sc(Fv)(2)](2) exhibited 75%-85% immunoreactivity, with nonspecific binding between 0.8% and 1.2%. Size-exclusion high-performance liquid chromatography showed sc(Fv)(2) as a 60-kDa protein and [sc(Fv)(2)](2) as a 120-kDa protein. Blood clearance studies showed the elimination half-life of (99m)Tc-labeled sc(Fv)(2) as 144 min and that of [sc(Fv)(2)](2) as 307 min. Whole-body clearance studies confirmed the rapid elimination of scFv's, with half-lives of 184 +/- 19 min for sc(Fv)(2) and 265 +/- 39 min for [sc(Fv)(2)](2) (P < 0.001). At 6 h after administration, the tumor localization was 7.2 +/- 0.7 percentage injected dose per gram of tumor (%ID/g) for (99m)Tc-sc(Fv)(2). (99m)Tc-[sc(Fv)(2)](2) showed a tumor uptake of 19.1 +/- 1.1 %ID/g at the same time; the amount of radioactivity in the tumors was 4-fold higher than in the spleen and kidneys and 2-fold higher than in the liver. Macroautoradiography performed at 6 and 16 h after administration clearly detected the tumor with both scFv's. CONCLUSION: (99m)Tc-labeled multivalent scFv's show good tumor-targeting characteristics and high radiolocalization indices (tumor-to-background ratio). These reagents, therefore, have the potential for use in clinical imaging studies of cancer in the field of nuclear medicine.

Airborne fungal spore monitoring in a protective environment during hospital construction, and correlation with an outbreak of invasive aspergillosis.

OBJECTIVE: Evaluate aerobiological monitoring for fungal spores during hospital construction and correlate results with an outbreak of invasive aspergillosis (IA). DESIGN: Prospective air sampling for molds was done using the gravity air-settling plate (GASP) method. SETTING: A university medical center special care unit consisting of single-patient rooms with high-efficiency particulate air filtration under positive pressure. PATIENTS: Five neutropenic patients who subsequently developed IA. RESULTS: Four of the five patients with IA were housed in rooms adjacent to a construction staging area. Aerobiological monitoring detected an increase in the number of airborne fungal spores including Aspergillus species in these rooms; however, increased counts preceded IA diagnosis by 1 to 7 days in only three of the five patients. Swab cultures of the exhaust vents within each room confirmed results from air-settling plates. Follow-up monitoring, using the GASP method, demonstrated that control procedures were effective in reducing air mold contamination. CONCLUSION: The GASP method, although able to demonstrate that infection control measures reduced mold contamination of the air, was insensitive to detect levels of mold contaminates in time to prevent IA.

Evaluation of three commercial screening tests for AIDS virus antibodies.

Three commercial enzyme-linked immunosorbent assays (ELISA) for acquired immune deficiency syndrome (AIDS) virus antibodies were evaluated using serum that had been characterized by an ELISA and western blot procedure developed at the University of California at Davis (UCD). Each of the commercial tests was more specific than the UCD ELISA, but the UCD ELISA was more sensitive in the detection of sera that lacked reactivity by western blot to the envelope glycoprotein (gp-41). The HTLV-III Bio-EnzaBead (Litton Bionetics, Charleston, SC) was less sensitive and specific than the Abbott HTLV-III EIA (Abbott Laboratories, North Chicago, IL) or the Virgo HTLV-III ELISA (Electro-Nucleonics Inc., Columbia, MD). Overall, 22.9% (57 of 250) and 51.0% of sera that were repeatedly (X2) positive by commercial screening kits tested at blood donor centers and clinical laboratories, respectively, were confirmed by western blot. These results indicate that the screening assays for AIDS virus antibodies are not equal in performance and that positive screening test results must be confirmed by a more specific test like western blot before results are released.

Evidence for the Role of Cyclic AMP-Responsive Elements in Human Virus Replication and Disease.

We review the involvement of the cyclic AMP responsive DNA element (CRE) and the ATF/CREB (activating transcription factor/CRE binding protein) family of transcription factors in the regulation and pathology of clinically important viruses that infect humans, including the herpesviridae, adenoviridae, parvoviridae, hepadnaviridae, and retroviridae families. CRE sequences found in specific regulatory elements of human viruses are listed, and the functional evidence for CRE activity, in the form of DNA binding assays, mutational studies, transfection and transcriptional activation experiments, or in vitro transcription assays, is summarized. Manipulation of cellular processes is required for virus replication in human cells following infection. A primary target of many viruses is the cellular transcription machinery, and several human viruses contain transcriptional activator and repressor proteins that affect cellular transcription. Through their effect on cellular transcription, viral genes alter the pattern of cellular gene expression, and thereby affect the differentiation state and cell cycle progression of the infected cell. We summarize evidence demonstrating that the CRE and its binding proteins are involved in the activity of the viruses, implicating their function in the pathogenesis of human diseases. The targeting of specific transcription factor pathways as a potential therapeutic approach is discussed. Copyright 1996 S. Karger AG, Basel

Genome diversity among regional populations of Francisella tularensis subspecies tularensis and Francisella tularensis subspecies holarctica isolated from the US.

Francisella tularensis is a highly infectious facultative intracellular pathogen that is considered a potential agent of bioterrorism. Four different F. tularensis subspecies have been identified and they appear to display different ecological and virulence characteristics as well as differences in geographical distribution. One simple explanation for the variation in ecological and virulence characteristics is that they are conferred by differences in genome content. To characterize genome content among stains isolated from United States, we have used a DNA microarray designed from a shotgun library of a reference strain. Polymorphisms distributed among polyphyletic sets of strains was the most common pattern of genome alteration observed, indicating that strain-specific genome variability is significant. Nonetheless, 13 different contiguous segments of the genome were found to be missing exclusively in each of the subsp. holarctica strains tested. All 13 are associated with repeat sequences or transposases that could promote insertion/deletion events. Comparison of the live vaccine strain to other holarctica strains also identified three regions that are absent exclusively in the live vaccine strain derived from holarctica.

Characterization of a human myxoid malignant fibrous histiocytoma cell line, OH931.

Malignant fibrous histiocytoma (MFH), the most common soft-tissue sarcoma of late adult life, includes several histopathologic subtypes. The myxoid MFH subtype is characterized by the presence of abundant mucopolysaccharide within a loose connective tissue stroma. Although the myxoid variant is typically distinguished clinically by its better prognosis, we report a case of myxoid MFH that exhibited an aggressive phenotype with early metastases and death. A cell line, OH931, was established from this myxoid MFH. The primary tumor, OH931 cell line, and cells recovered from tumors generated in nude mice shared similar morphologic features, including the continued production of abundant mucopolysaccharide. Cytogenetic analysis of the primary tumor and a subsequently established cell line (OH931) revealed a complex hypertriploid mainline. Chromosomal breakpoints involved in all three specimens analyzed (diagnostic biopsy, definitive surgical, and cell line) included 1p33, 1q21, 2p14, 4p15, 5q13, 12q13, 14p13, 15p13, 19q13 and 20q13.1. The OH931 cell line, which appears to maintain its peculiar characteristics in vitro, should be useful in studies investigating the role of mucopolysaccharide production in the process of neoplasia.