Searching the Biological Literature

Table of Contents. Chapter 1. Organization of the Scientific Literature and the Flow of Information in the Sciences. Chapter 2. Primary Sources. Chapter 3. Reference Sources. Chapter 4. Databases. Chapter 5. Basic Principles of Searching and Search Logic Chapter 6. Citation Indexes and Citation Searching . Chapter 7. The Citation Concept and its Impact on Society Chapter 8. Resources on the World Wide Web Chapter 9. U. S. Government Publications Chapter 10. Lessons Learned Inde

Radiosensitivity and characterisation of a newly established cell line from an epithelioid sarcoma.

A new human tumour cell line (designated HX 165c) has been established from an epithelioid sarcoma presenting in a 28 year old male. The cells grew as an adherent monolayer with a doubling time of 38 h and had mainly epithelial morphology but with areas of mesenchymal-like cytoplasmic extensions. The mixed epithelial-mesenchymal phenotype was also apparent by intermediate filament analysis which showed reactivity to vimentin and keratin. The cells were tumorigenic in nude mice and aneuploid, possessing a mean chromosome number of 65. In vitro cloning determinations gave colony-forming efficiencies of 0.01% in an anchorage-independent soft agar assay and 34% in a monolayer anchorage-dependent assay. The cells were in the mid-range for radiosensitivity of human tumour cells (surviving fraction at 2 Gy of 0.39). In addition, experiments utilising continuous low dose rate irradiation at 3.2 cGy min-1, showed that the cells possessed only a small capacity to recover from radiation damage (dose reduction factor at 1% cell survival of 1.15 for 150 versus 3.2 cGy min-1). This cell line, being only the second we are aware of to be established from this rare soft tissue sarcoma, should be useful in helping to ascertain the histogenesis of epithelioid sarcoma

Vertex Models and Random Labyrinths: Phase Diagrams for Ice-type Vertex Models

We propose a simple geometric recipe for constructing phase diagrams for a general class of vertex models obeying the ice rule. The disordered phase maps onto the intersecting loop model which is interesting in its own right and is related to several other statistical mechanical models. This mapping is also useful in understanding some ordered phases of these vertex models as they correspond to the polymer loop models with cross-links in their vulcanised phase.Comment: 8 pages, 6 figure

High intrinsic radiosensitivity of a newly established and characterised human embryonal rhabdomyosarcoma cell line.

A new human rhabdomyosarcoma cell line (HX170c) has been established from a paratesticular embryonal tumour in a 5-year-old male. The cells grew as an adherent monolayer with a doubling time of 32 h and showed pleomorphic features. Intermediate filament analysis revealed the line to be mesenchymal in origin (reactivity to vimentin and desmin antibodies). The line was tumorigenic in nude mice, possessed elevated levels of creatine phosphokinase (mainly of the MM isoenzyme form) and had a near diploid mean chromosome number of 50. In vitro cell cloning determinations gave colony forming efficiencies of 0.01% in soft agar and 24% in a monolayer anchorage-dependent assay. Radiosensitivity determinations using a monolayer clonogenic assay with feeder layer support showed the cells to be among the more radiosensitive human tumour cell types (surviving fraction at 2 Gy of 0.26) that have been investigated. Furthermore, experiments utilising continuous low dose rate radiation at 3.2 cGy min-1, showed that, under these experimental conditions, the cells possessed only a very low capacity to recover from radiation-induced damage (dose reduction factor at 1% cell survival of 1.07 for 150 versus 3.2 cGy min-1). As other human tumour cells of an embryonal cell origin (e.g. neuroblastoma and germ cell tumours of the testis) have also been shown to be radiosensitive it appears that sensitivity to radiation may be a common property of this group of tumours

Characterization and modulation of drug resistance of human paediatric rhabdomyosarcoma cell lines

The role of multidrug resistance (MDR) and p53 functional status in the treatment of paediatric rhabdomyosarcoma is unclear. We have characterized a panel of seven human rhabdomyosarcoma cell lines for MDR and p53 phenotype. None of the cell lines had P-glycoprotein (P-gp) or multidrug resistance-related protein (MRP) detectable by Western blotting, whereas immunohistochemistry suggested that very low levels of MDR proteins may be present in some of the lines. RT-PCR studies indicated that mdr-1, mrp-1 and lrp mRNA was present in 5/7, 7/7 and 5/7 lines respectively. The function of p53 is compromised in six of the lines, either through mutation of the p53 gene or by overexpression of mdm-2. The sensitivity of many of the cell lines to vincristine could be modulated above 2-fold and as high as 16-fold using two modulating agents, PSC833 and VX710 (with VX710 being a significantly more potent modulator of the rhabdomyosarcoma lines). PSC833 also increased vincristine accumulation in all of the lines from 1.2- to 2.2-fold. These results suggest that some of these cell lines have low levels of multidrug resistance. The level of MDR proteins is very low and therefore difficult to detect, but may be sufficient to confer low-level, but clinically relevant, resistance to some cytotoxic agents, especially vincristine. These cell lines will therefore provide a suitable model to test new strategies in treatment and for further understanding relationships between protein expression and drug resistance. © 2000 Cancer Research Campaig