NobleBlocks

University of Veterinary Medicine

UniversityBudapest, Budapest, Hungary

Research output, citation impact, and the most-cited recent papers from University of Veterinary Medicine (Hungary). Aggregated across the NobleBlocks index of 300M+ scholarly works.

Total works
10.2K
Citations
265.1K
h-index
153
i10-index
5.9K
Also known as
Royal Academy of Veterinary MedicineRoyal Institute for Veterinary MedicineUniversity of Veterinary MedicineÁllatorvostudományi Egyetem

Top-cited papers from University of Veterinary Medicine

A Randomized Trial of Chemoradiotherapy and Chemotherapy after Resection of Pancreatic Cancer
John P. Neoptolemos, Deborah Stocken, Helmut Friess, Claudio Bassi +4 more
2004· New England Journal of Medicine2.7Kdoi:10.1056/nejmoa032295

BACKGROUND: The effect of adjuvant treatment on survival in pancreatic cancer is unclear. We report the final results of the European Study Group for Pancreatic Cancer 1 Trial and update the interim results. METHODS: In a multicenter trial using a two-by-two factorial design, we randomly assigned 73 patients with resected pancreatic ductal adenocarcinoma to treatment with chemoradiotherapy alone (20 Gy over a two-week period plus fluorouracil), 75 patients to chemotherapy alone (fluorouracil), 72 patients to both chemoradiotherapy and chemotherapy, and 69 patients to observation. RESULTS: The analysis was based on 237 deaths among the 289 patients (82 percent) and a median follow-up of 47 months (interquartile range, 33 to 62). The estimated five-year survival rate was 10 percent among patients assigned to receive chemoradiotherapy and 20 percent among patients who did not receive chemoradiotherapy (P=0.05). The five-year survival rate was 21 percent among patients who received chemotherapy and 8 percent among patients who did not receive chemotherapy (P=0.009). The benefit of chemotherapy persisted after adjustment for major prognostic factors. CONCLUSIONS: Adjuvant chemotherapy has a significant survival benefit in patients with resected pancreatic cancer, whereas adjuvant chemoradiotherapy has a deleterious effect on survival.

Resistance of<i>Bacillus</i>Endospores to Extreme Terrestrial and Extraterrestrial Environments
Wayne L. Nicholson, Nobuo Munakata, G. Horneck, H. J. Melosh +1 more
2000· Microbiology and Molecular Biology Reviews2.0Kdoi:10.1128/mmbr.64.3.548-572.2000

Endospores of Bacillus spp., especially Bacillus subtilis, have served as experimental models for exploring the molecular mechanisms underlying the incredible longevity of spores and their resistance to environmental insults. In this review we summarize the molecular laboratory model of spore resistance mechanisms and attempt to use the model as a basis for exploration of the resistance of spores to environmental extremes both on Earth and during postulated interplanetary transfer through space as a result of natural impact processes.

Global monitoring of antimicrobial resistance based on metagenomics analyses of urban sewage
René S. Hendriksen, Patrick Munk, Patrick Murigu Kamau Njage, Bram van Bunnik +4 more
2019· Nature Communications1.2Kdoi:10.1038/s41467-019-08853-3

Antimicrobial resistance (AMR) is a serious threat to global public health, but obtaining representative data on AMR for healthy human populations is difficult. Here, we use metagenomic analysis of untreated sewage to characterize the bacterial resistome from 79 sites in 60 countries. We find systematic differences in abundance and diversity of AMR genes between Europe/North-America/Oceania and Africa/Asia/South-America. Antimicrobial use data and bacterial taxonomy only explains a minor part of the AMR variation that we observe. We find no evidence for cross-selection between antimicrobial classes, or for effect of air travel between sites. However, AMR gene abundance strongly correlates with socio-economic, health and environmental factors, which we use to predict AMR gene abundances in all countries in the world. Our findings suggest that global AMR gene diversity and abundance vary by region, and that improving sanitation and health could potentially limit the global burden of AMR. We propose metagenomic analysis of sewage as an ethically acceptable and economically feasible approach for continuous global surveillance and prediction of AMR.

Generation and testing of clinical-grade exosomes for pancreatic cancer
Mayela Carolina Mendt, Sushrut Kamerkar, Hikaru Sugimoto, Kathleen M. McAndrews +4 more
2018· JCI Insight782doi:10.1172/jci.insight.99263

Exosomes are extracellular vesicles produced by all cells with a remarkable ability to efficiently transfer genetic material, including exogenously loaded siRNA, to cancer cells. Here, we report on a bioreactor-based, large-scale production of clinical-grade exosomes employing good manufacturing practice (GMP) standards. A standard operating procedure was established to generate engineered exosomes with the ability to target oncogenic Kras (iExosomes). The clinical-grade GMP iExosomes were tested in multiple in vitro and in vivo studies to confirm suppression of oncogenic Kras and an increase in the survival of several mouse models with pancreatic cancer. We perform studies to determine the shelf life, biodistribution, toxicology profile, and efficacy in combination with chemotherapy to inform future clinical testing of GMP iExosomes. Collectively, this report illustrates the process and feasibility of generating clinical-grade exosomes for various therapies of human diseases.

Investigating the optimal size of anticancer nanomedicine
Li Tang, Xujuan Yang, Qian Yin, Kaimin Cai +4 more
2014· Proceedings of the National Academy of Sciences659doi:10.1073/pnas.1411499111

Nanomedicines (NMs) offer new solutions for cancer diagnosis and therapy. However, extension of progression-free interval and overall survival time achieved by Food and Drug Administration-approved NMs remain modest. To develop next generation NMs to achieve superior anticancer activities, it is crucial to investigate and understand the correlation between the physicochemical properties of NMs (particle size in particular) and their interactions with biological systems to establish criteria for NM optimization. Here, we systematically evaluated the size-dependent biological profiles of three monodisperse drug-silica nanoconjugates (NCs; 20, 50, and 200 nm) through both experiments and mathematical modeling and aimed to identify the optimal size for the most effective anticancer drug delivery. Among the three NCs investigated, the 50-nm NC shows the highest tumor tissue retention integrated over time, which is the collective outcome of deep tumor tissue penetration and efficient cancer cell internalization as well as slow tumor clearance, and thus, the highest efficacy against both primary and metastatic tumors in vivo.

Quantum dots in imaging, drug delivery and sensor applications
Cristian Matea, Teodora Mocan, Flaviu Tăbăran, Teodora Pop +4 more
2017· International Journal of Nanomedicine653doi:10.2147/ijn.s138624

Quantum dots (QDs), also known as nanoscale semiconductor crystals, are nanoparticles with unique optical and electronic properties such as bright and intensive fluorescence. Since most conventional organic label dyes do not offer the near-infrared (>650 nm) emission possibility, QDs, with their tunable optical properties, have gained a lot of interest. They possess characteristics such as good chemical and photo-stability, high quantum yield and size-tunable light emission. Different types of QDs can be excited with the same light wavelength, and their narrow emission bands can be detected simultaneously for multiple assays. There is an increasing interest in the development of nano-theranostics platforms for simultaneous sensing, imaging and therapy. QDs have great potential for such applications, with notable results already published in the fields of sensors, drug delivery and biomedical imaging. This review summarizes the latest developments available in literature regarding the use of QDs for medical applications.

Lung-resident eosinophils represent a distinct regulatory eosinophil subset
Claire Mesnil, Stéfanie Raulier, Geneviève Paulissen, Xue Xiao +4 more
2016· Journal of Clinical Investigation556doi:10.1172/jci85664

Increases in eosinophil numbers are associated with infection and allergic diseases, including asthma, but there is also evidence that eosinophils contribute to homeostatic immune processes. In mice, the normal lung contains resident eosinophils (rEos), but their function has not been characterized. Here, we have reported that steady-state pulmonary rEos are IL-5-independent parenchymal Siglec-FintCD62L+CD101lo cells with a ring-shaped nucleus. During house dust mite-induced airway allergy, rEos features remained unchanged, and rEos were accompanied by recruited inflammatory eosinophils (iEos), which were defined as IL-5-dependent peribronchial Siglec-FhiCD62L-CD101hi cells with a segmented nucleus. Gene expression analyses revealed a more regulatory profile for rEos than for iEos, and correspondingly, mice lacking lung rEos showed an increase in Th2 cell responses to inhaled allergens. Such elevation of Th2 responses was linked to the ability of rEos, but not iEos, to inhibit the maturation, and therefore the pro-Th2 function, of allergen-loaded DCs. Finally, we determined that the parenchymal rEos found in nonasthmatic human lungs (Siglec-8+CD62L+IL-3Rlo cells) were phenotypically distinct from the iEos isolated from the sputa of eosinophilic asthmatic patients (Siglec-8+CD62LloIL-3Rhi cells), suggesting that our findings in mice are relevant to humans. In conclusion, our data define lung rEos as a distinct eosinophil subset with key homeostatic functions.

A Scoring Index for Disease Activity in Canine Inflammatory Bowel Disease
Albert E. Jergens, Ceinwen A. Schreiner, Dagmar Ε. Frank, Yosiya Niyo +4 more
2003· Journal of Veterinary Internal Medicine476doi:10.1111/j.1939-1676.2003.tb02450.x

The clinical course of inflammatory bowel disease (IBD) in dogs is characterized by spontaneous exacerbations and remissions, which makes assessment of disease burden difficult. The objectives of this study were to develop a scoring system for evaluation of canine IBD activity and to validate this scoring method by correlating it to objective laboratory and histologic indices of intestinal inflammation. Fifty-eight dogs with IBD were evaluated prospectively and compared to 9 disease-free control dogs. Clinical disease activity was quantified by a simple scoring system, the canine IBD activity index (CIBDAI), and compared to serum concentrations of C-reactive protein (CRP), haptoglobin (HAP), alpha-acid glycoprotein (AGP), and serum amyloid A (SAA), as well as histology scores derived from endoscopic biopsy specimens. Forty-six dogs were available for a reevaluation of the CIBDAI, CRP HAP, and AGP, and 34 dogs had repeat analysis of SAA performed after medical therapy. Serum concentrations of CRP were significantly (P < .02) increased in dogs with CIBDAI scores > or = 5 (mild disease activity or greater) compared to controls. Among IBD dogs, the CIBDAI showed good correlation (r = 0.82, P < .0001) to both histology and HAP scores, but CRP also was a strong co-correlate of disease activity. The IBD dogs showed significantly (P < .0001) decreased CIBDAI and CRP values but significantly (P < .0001) increased HAP concentrations after medical therapy compared to pretreatment values. We conclude that the CIBDAI is a reliable measure of inflammatory activity in canine IBD and that CRP is suitable for laboratory evaluation of the effect of therapy in these patients.

Hypoxia-inducible factor 2α regulates macrophage function in mouse models of acute and tumor inflammation
Hongxia Z. Imtiyaz, Emily Williams, Michele M. Hickey, Shetal Patel +4 more
2010· Journal of Clinical Investigation454doi:10.1172/jci39506

Hypoxia-inducible factor 1alpha (HIF-1alpha) and HIF-2alpha display unique and sometimes opposing activities in regulating cellular energy homeostasis, cell fate decisions, and oncogenesis. Macrophages exposed to hypoxia accumulate both HIF-1alpha and HIF-2alpha, and overexpression of HIF-2alpha in tumor-associated macrophages (TAMs) is specifically correlated with high-grade human tumors and poor prognosis. However, the precise role of HIF-2alpha during macrophage-mediated inflammatory responses remains unclear. To fully characterize cellular hypoxic adaptations, distinct functions of HIF-1alpha versus HIF-2alpha must be elucidated. We demonstrate here that mice lacking HIF-2alpha in myeloid cells (Hif2aDelta/Delta mice) are resistant to lipopolysaccharide-induced endotoxemia and display a marked inability to mount inflammatory responses to cutaneous and peritoneal irritants. Furthermore, HIF-2alpha directly regulated proinflammatory cytokine/chemokine expression in macrophages activated in vitro. Hif2aDelta/Delta mice displayed reduced TAM infiltration in independent murine hepatocellular and colitis-associated colon carcinoma models, and this was associated with reduced tumor cell proliferation and progression. Notably, HIF-2alpha modulated macrophage migration by regulating the expression of the cytokine receptor M-CSFR and the chemokine receptor CXCR4, without altering intracellular ATP levels. Collectively, our data identify HIF-2alpha as an important regulator of innate immunity, suggesting it may be a useful therapeutic target for treating inflammatory disorders and cancer.

Metal nanoparticles fabricated by green chemistry using natural extracts: biosynthesis, mechanisms, and applications
Hesham R. El‐Seedi, Rehan M. El-Shabasy, Shaden A. M. Khalifa, Aamer Saeed +4 more
2019· RSC Advances451doi:10.1039/c9ra02225b

Nanoparticles (NPs) are new inspiring clinical targets that have emerged from persistent efforts with unique properties and diverse applications. However, the main methods currently utilized in their production are not environmentally friendly. With the aim of promoting a green approach for the synthesis of NPs, this review describes eco-friendly methods for the preparation of biogenic NPs and the known mechanisms for their biosynthesis. Natural plant extracts contain many different secondary metabolites and biomolecules, including flavonoids, alkaloids, terpenoids, phenolic compounds and enzymes. Secondary metabolites can enable the reduction of metal ions to NPs in eco-friendly one-step synthetic processes. Moreover, the green synthesis of NPs using plant extracts often obviates the need for stabilizing and capping agents and yields biologically active shape- and size-dependent products. Herein, we review the formation of metallic NPs induced by natural extracts and list the plant extracts used in the synthesis of NPs. In addition, the use of bacterial and fungal extracts in the synthesis of NPs is highlighted, and the parameters that influence the rate of particle production, size, and morphology are discussed. Finally, the importance and uniqueness of NP-based products are illustrated, and their commercial applications in various fields are briefly featured.

Handbook of Food Spoilage Yeasts
Tibor Deák
2007441doi:10.1201/9781420044942

Far more than a simple update and revision, the Handbook of Food Spoilage Yeasts, Second Edition extends and restructures its scope and content to include important advances in the knowledge of microbial ecology, molecular biology, metabolic activity, and strategy for the prohibition and elimination of food borne yeasts. The author incorporates new

Interleukin-12 and interleukin-18 synergistically induce murine tumor regression which involves inhibition of angiogenesis.
Christina Coughlin, Kevin E. Salhany, Maria Wysocka, E Aruga +4 more
1998· Journal of Clinical Investigation423doi:10.1172/jci1555

The antitumor effect and mechanisms activated by murine IL-12 and IL-18, cytokines that induce IFN-gamma production, were studied using engineered SCK murine mammary carcinoma cells. In syngeneic A/J mice, SCK cells expressing mIL-12 or mIL-18 were less tumorigenic and formed tumors more slowly than control cells. Neither SCK.12 nor SCK.18 cells protected significantly against tumorigenesis by distant SCK cells. However, inoculation of the two cell types together synergistically protected 70% of mice from concurrently injected distant SCK cells and 30% of mice from SCK cells established 3 d earlier. Antibody neutralization studies revealed that the antitumor effects of secreted mIL-12 and mIL-18 required IFN-gamma. Interestingly, half the survivors of SCK.12 and/or SCK.18 cells developed protective immunity suggesting that anti-SCK immunity is unlikely to be responsible for protection. Instead, angiogenesis inhibition, assayed by Matrigel implants, appeared to be a property of both SCK.12 and SCK.18 cells and the two cell types together produced significantly greater systemic inhibition of angiogenesis. This suggests that inhibition of tumor angiogenesis is an important part of the systemic antitumor effect produced by mIL-12 and mIL-18.

Mosaicplasty for the Treatment of Osteochondritis Dissecans of the Talus: Two to Seven Year Results in 36 Patients
László Hangody, Gary Kish, László Módis, Imre Szerb +3 more
2001· Foot & Ankle International356doi:10.1177/107110070102200704

An osteochondral defect (OCD) is known as a symptomatic lesion causing pain, recurrent synovitis, and altered joint mechanics most commonly in a weight-bearing joint. Loose bodies may develop, which may then cause joint destruction and/or locking. The damage to the articular surface is most likely a precursor of ankle osteoarthritis. With the recent advances in diagnostic imaging, such as MRI, as well as the development of ankle arthroscopy, the identification and classification of these lesions has become much more precise. This allows more accurate staging and improves treatment recommendations. The assessment of a particular treatment is also improved. A variety of treatment alternatives are now available. These include arthroscopic procedures including debridement, retrograde drilling, and bone grafting. Compared to open treatment, arthroscopic procedures may be particularly advantageous in the treatment of small defects and stable OCD lesions. Until recently, however, favorable results have been less predictable for large or unstable osteochondral defects. We treat these more difficult lesions with a mosaic autogenous osteochondral transplantation. In our hands, this appears to provide an optimal treatment result. The present report evaluates the clinical outcome of 36 patients followed for two to seven years after a mosaicplasty autogenous osteochondral transplantation from a non or less weight bearing portion of the knee to the ipsilateral talus. Ankle function was measured by the Hannover scoring system and showed good to excellent results in 34 cases (94%) with no long term donor site morbidity. The encouraging clinical results are supplemented with radiographs and histology, which support the premise of lasting relief of symptoms and prevention of ankle arthrosis.

Advances in covalent kinase inhibitors
Ayah Abdeldayem, Yasir S. Raouf, Stefan N. Constantinescu, Richard Moriggl +1 more
2020· Chemical Society Reviews325doi:10.1039/c9cs00720b

Over the past decade, covalent kinase inhibitors (CKI) have seen a resurgence in drug discovery. Covalency affords a unique set of advantages as well as challenges relative to their non-covalent counterpart. After reversible protein target recognition and binding, covalent inhibitors irreversibly modify a proximal nucleophilic residue on the protein via reaction with an electrophile. To date, the acrylamide group remains the predominantly employed electrophile in CKI development, with its incorporation in the majority of clinical candidates and FDA approved covalent therapies. Nonetheless, in recent years considerable efforts have ensued to characterize alternative electrophiles that exhibit irreversible or reversibly covalent binding mechanisms towards cysteine thiols and other amino acids. This review article provides a comprehensive overview of CKIs reported in the literature over a decade period, 2007-2018. Emphasis is placed on the rationale behind warhead choice, optimization approach, and inhibitor design. Current FDA approved CKIs are also highlighted, in addition to a detailed analysis of the common trends and themes observed within the listed data set.

Smallpox DNA Vaccine Protects Nonhuman Primates against Lethal Monkeypox
Jay W. Hooper, E. Ashley Thompson, Catherine L. Wilhelmsen, Murray C. Zimmerman +4 more
2004· Journal of Virology318doi:10.1128/jvi.78.9.4433-4443.2004

Two decades after a worldwide vaccination campaign was used to successfully eradicate naturally occurring smallpox, the threat of bioterrorism has led to renewed vaccination programs. In addition, sporadic outbreaks of human monkeypox in Africa and a recent outbreak of human monkeypox in the U.S. have made it clear that naturally occurring zoonotic orthopoxvirus diseases remain a public health concern. Much of the threat posed by orthopoxviruses could be eliminated by vaccination; however, because the smallpox vaccine is a live orthopoxvirus vaccine (vaccinia virus) administered to the skin, the vaccine itself can pose a serious health risk. Here, we demonstrate that rhesus macaques vaccinated with a DNA vaccine consisting of four vaccinia virus genes (L1R, A27L, A33R, and B5R) were protected from severe disease after an otherwise lethal challenge with monkeypox virus. Animals vaccinated with a single gene (L1R) which encodes a target of neutralizing antibodies developed severe disease but survived. This is the first demonstration that a subunit vaccine approach to smallpox-monkeypox immunization is feasible.

Histological and bacteriological evaluation of digital dermatitis in cattle, with special reference to spirochaetes and <i>Campylobacter faecalis</i>
Dörte Döpfer, A. A. H. M. ter Huurne, J. L. Cornelisse, Alphons J.A.M. van Asten +4 more
1997· Veterinary Record311doi:10.1136/vr.140.24.620

Tissue samples from the feet of slaughtered cattle exhibiting different stages of digital dermatitis were sectioned and stained with haematoxylin and eosin and silver staining techniques. Three morphological variations of spirochaetes were observed, whereas control samples from feet which were macroscopically negative for digital dermatitis were also negative for spirochaetes. In an immunofluorescence test, Campylobacter faecalis was found to be abundant on superficial wound smears from the classical ulceration of digital dermatitis.

Trophic transfer and biomagnification potential of environmental contaminants (heavy metals) in aquatic ecosystems
Nadhirah Binti Saidon, R Szabó, Péter Budai, József Lehel
2023· Environmental Pollution307doi:10.1016/j.envpol.2023.122815

Physical, chemical weathering and volcanic eruptions release heavy metals into soils and surface waters naturally. Contaminants from anthropogenic sources originated from industrial and municipality waste substantially modify and increase their contributions. They are then absorbed by fish gills, amphipod cuticles, and other sensitive organs of aquatic creatures. This article discusses the essences on the determination, potential and plausible factors of trophic transfer and biomagnification of environmental contaminants particularly heavy metals across aquatic ecosystem. In general, arsenic is found to be bio-diminished across food webs in freshwater ecosystem while it biomagnified in marine ecosystem of higher trophic level (tertiary consumer of predatory fish) and dilute its concentration from lower trophic level (from producer to bottom level of consumer, secondary and lastly to tertiary consumer (forage fish)). Early study for Cadmium shown that it has no potential for biomagnification while later studies prove that cadmium does magnify for gastropod and epiphyte-based food webs. Mercury shown obvious biomagnification potential where it can bio-magnify from trophic level as low as particulate organic matter (POM) to higher trophic of fish. These findings proved that aquatic ecosystems must be preserved from contamination not just for human benefit, but also to prevent environmental degradation and biodiversity loss.

ECEIM consensus statement on equine metabolic syndrome
Andy E. Durham, Nicholas Frank, Cathy M. McGowan, Nicola J. Menzies‐Gow +4 more
2019· Journal of Veterinary Internal Medicine293doi:10.1111/jvim.15423

Equine metabolic syndrome (EMS) is a widely recognized collection of risk factors for endocrinopathic laminitis. The most important of these risk factors is insulin dysregulation (ID). Clinicians and horse owners must recognize the presence of these risk factors so that they can be targeted and controlled to reduce the risk of laminitis attacks. Diagnosis of EMS is based partly on the horse's history and clinical examination findings, and partly on laboratory testing. Several choices of test exist which examine different facets of ID and other related metabolic disturbances. EMS is controlled mainly by dietary strategies and exercise programs that aim to improve insulin regulation and decrease obesity where present. In some cases, pharmacologic aids might be useful. Management of an EMS case is a long-term strategy requiring diligence and discipline by the horse's carer and support and guidance from their veterinarians.

Genomic analysis of sewage from 101 countries reveals global landscape of antimicrobial resistance
Patrick Munk, Christian Brinch, Frederik Duus Møller, Thomas Nordahl Petersen +4 more
2022· Nature Communications291doi:10.1038/s41467-022-34312-7

Antimicrobial resistance (AMR) is a major threat to global health. Understanding the emergence, evolution, and transmission of individual antibiotic resistance genes (ARGs) is essential to develop sustainable strategies combatting this threat. Here, we use metagenomic sequencing to analyse ARGs in 757 sewage samples from 243 cities in 101 countries, collected from 2016 to 2019. We find regional patterns in resistomes, and these differ between subsets corresponding to drug classes and are partly driven by taxonomic variation. The genetic environments of 49 common ARGs are highly diverse, with most common ARGs carried by multiple distinct genomic contexts globally and sometimes on plasmids. Analysis of flanking sequence revealed ARG-specific patterns of dispersal limitation and global transmission. Our data furthermore suggest certain geographies are more prone to transmission events and should receive additional attention.

Genetic background alters the spectrum of tumors that develop in p53‐deficient mice
Michael Harvey, M J McArthur, Charles A. Montgomery, Allan Bradley +1 more
1993· The FASEB Journal288doi:10.1096/fasebj.7.10.8344491

Using gene targeting in embryonic stem cells, we have generated mice with one or two null p53 germ line alleles. Mice with both p53 alleles inactivated are developmentally normal but highly susceptible to the early development of spontaneous tumors. Initial studies were performed in mice with a mixed inbred genetic background (75% C57BL/6 and 25% 129/Sv) (Donehower et al., Nature (London) 356, 215-221, 1992). To study the effect of genetic background on tumorigenesis in p53-deficient mice, we have put the p53 null allele into a pure 129/Sv background and monitored tumor development. 129/Sv mice with two p53 null alleles developed tumors sooner than the mixed genetic background p53-deficient animals. The most frequently observed tumor in p53 null mice of both genetic backgrounds was a malignant lymphoma. Because the 129/Sv strain has a low incidence of lymphoma, the frequent occurrence of lymphomas in all p53 null mice suggests that this particular tumor type may be a direct result of p53 loss and not a result of a particular genetic background. In addition to malignant lymphomas, the 129/Sv p53-deficient mice showed an increased incidence of aggressive teratocarcinomas (8 of 18 tumor-bearing males), a tumor type rare in virtually all inbred mice except for 129 strains. Thus, it appears that loss of p53 may accelerate a prior tumor predisposition and that genetic background can play a role in mediating both the rate and spectrum of tumor development in these mice.