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C Rowlatt

Publications and source records attributed to C Rowlatt.

At least 19 recordsLinked to original sources
PubMed1989

Comparison of the significance of three histopathological thresholds of malignancy in experimental colorectal tumours.

The purpose of this experiment was to study sequential histogenesis of colonic epithelial tumours in the dimethylhydrazine (DMH) induced rat colon cancer model. Seventy outbred female Wistar rats treated with DMH (40 mg/kg, subcutaneously weekly for five weeks) were killed and autopsied in batches of 10 every five weeks from the 10th to 40th weeks from first treatment. The resulting 378 colonic lesions were assigned to benign or malignant categories using each of three standard histopathological thresholds of malignancy: alpha, the transition from dysplasia to intraepithelial carcinoma; beta, invasion through the crypt basement membrane; and gamma, invasion through the muscularis mucosae. These comprised 79 'benign' and 299 'malignant' or 273 'benign' and 141 'malignant' lesions depending on the threshold (alpha or gamma) assigned (p less than 0.001). Decreasing ratios of pre-threshold to post-threshold lesions between 15 and 40 weeks (alpha, 2.0 to 0.051; beta, 3.5 to 0.57; gamma, 8.0 to 0.87) provide some support for an 'adenoma-carcinoma' progression for each. Comparison of time-dependent prevalence curves confirms that the alpha threshold (cyto-architecture) is qualitatively different from the beta and gamma thresholds (invasion), showing that the adenoma-carcinoma and de novo hypotheses need not be mutually exclusive. The time-dependent prevalence data support de novo origin of some carcinomas, as well as at least two other modes of accrual for neoplastic lesions.

1,2-Dimethylhydrazine↗
PubMed1986

Epithelial-stromal interactions in the adult bladder: urothelial growth, differentiation, and maturation on culture facsimiles of bladder stroma.

Analysis of the responsiveness of isolated adult urothelium to a series of different stromal cell-extracellular matrix combinations demonstrated the capacity of stromal cells to induce and maintain normal patterns of urothelial growth, differentiation, and maturation in vitro. By incorporating embryonic mesenchymal derived (Swiss 3T3) cells into type I collagen matrices, simplified three-dimensional tissue-like facsimiles of bladder stroma were derived. When recombined with sheets of isolated urothelium these facsimiles could approximately reproduce the capacity of natural stromal tissue to support the expression of normal urothelial tissue specific characteristics. In contrast cocultures between urothelia and monolayers of 3T3 cells, applied to the surface of planar collagen substrata could only permit urothelial cell attachment but not growth or differentiation whereas lethally irradiated 3T3 (feeder) cells, under similar experimental conditions, could support the maintenance of an immature or incompletely differentiated urothelium. Conditioned medium elaborated by cultured 3T3 cells could not stimulate further differentiation in urothelia cultured alone on planar collagen substrata. These studies indicate that a significant portion of the regulatory capacity of the stroma in stromal-urothelial interactions can be accounted for by the activities of a closely applied population of stromal cells, provided the cells are viable and presented to the urothelium in a three-dimensional context in combination with collagen. The capacity of embryonic mesenchymal cells to express properties appropriate to the development of a multilayered terminally differentiated urothelium suggests that normal interactions between adult urothelium and stroma are of limited specificity with the urothelium requiring an essential input of permissive signals only.

Animals↗
PubMed1986

A survey of surface glycoproteins of four human squamous cell carcinoma lines.

The major cell surface glycoprotein components of four new cell lines derived from human squamous cell carcinomas of the head and neck (TR126, TR131, TR138, TR146, Rupniak, H. T. et al., JNCI 75, 621-635, 1985) were identified by three complementary labelling methods. The profile of labelled glycoprotein components was very similar in the four cell lines, although quite large quantitative differences in individual bands were seen. Two galactoproteins, designated GPC-130 and GPC-80 (apparent molecular weight X 10(-3)) were labelled by galactose oxidase/NaB [3H]4 but in all four lines only GPC-130 was prominent. The cell surface galactose and N-Acetylgalactosaminyl residues of glycoproteins were quite highly sialylated, as the galactose oxidase/NaB [3H]4 reaction was increased by between 3- and 6-fold after neuraminidase treatment. The neuraminidase-galactose oxidase/NaB [3H]4 and NaIO4/NaB [3H]4 methods identified a complex profile of glycoprotein components, with very high molecular weight sialogalactoconjugates being prominent. The major sialoglycoproteins were GPC-205, GPC-175, GPC-155, GPC-90 and GPC-70 and in addition, GPC-130 and GPC-80 showed enhanced labelling. Lactoperoxidase catalyzed the iodination of a similar profile of high molecular weight glycoprotein components, with GPC-205 and GPC-175 being prominent in TR126, TR131 and TR146 but less evident in TR138. Overall, the profile of labelled glycoprotein components was similar to the pattern seen in the well differentiated transitional carcinoma lines RT112 and RT4 (Steele, J. G. et al., Biochim. Biophys. Acta. 732, 219-228, 1983).

Carcinoma, Squamous Cell↗
PubMed1985

Characteristics of four new human cell lines derived from squamous cell carcinomas of the head and neck.

Four human cell lines were established from biopsy specimens of squamous cell carcinomas of the larynx (TR131 and TR138), tongue (TR126), and buccal mucosa that had infiltrated a lymph node (TR146). All 4 lines readily formed colonies on a plastic substratum, but they were virtually incapable of forming colonies in an anchorage-independent semisolid support system of soft agar (cloning efficiencies, less than 0.02%). The proliferation of this group of tumor-derived cell lines, therefore, appeared to be highly anchorage dependent. Keratin filaments could be visualized in each line by indirect immunofluorescence with the use of polyclonal or monoclonal antibodies to keratins; staining with monospecific antibodies indicated that 3 of the 4 lines expressed simple epithelial keratins 8 and 18, whereas 1 of the 4 also expressed keratin 19. A panel of lectins revealed characteristic localization patterns distinct from those observed on other epithelial cell lines. Cells from 3 lines (TR131, TR138, and TR146) inoculated into nude mice (nu/nu) produced cystic nodules or unequivocal tumors having a histology indicating a squamous cell origin for the injected cells. Electron microscopy demonstrated that the cell lines covered a spectrum of differentiation capability ranging from the undifferentiated monolayer cultures of TR126 to the rather well differentiated, stratified cultures of TR131.

Adult↗
PubMed1985

An ultrastructural analysis of the physical organization of collagenous (type I) matrices: one determinant of urothelium maintenance in vitro.

Collagenous matrices, used as cell culture substrata, can be prepared from different collagen types in a variety of forms using a range of polymerization procedures. Type I collagen has been most frequently used either as dried collagen films or hydrated collagen gels. Sheets of isolated bladder urothelium, when plated onto such matrices prepared from type I collagen by different polymerization methods (eg. air-drying; NaOH; NaCl; NH3; or NH3 followed by glutaraldehyde crosslinking) demonstrate the capability of urothelial cells to attach to a variety of differently prepared matrices irrespective of polymerization procedure. In contrast, both cell proliferation and maintenance of the urothelium are markedly influenced by the polymerized form of the collagen matrix. Comparative ultrastructural (scanning and transmission electron microscopy) analysis of these matrices demonstrates dissimilarities in their physical organization. The level of filamentous, fibrillar or fibrous reaggregation of solubilized collagen molecules varies in relation to the polymerization procedure used viz, a) air dried matrices form a dense meshwork of many forms of collagen fibrils and associated filaments with an irregular surface array of coarser collagen fibres; b) matrices prepared by NaOH, NaCl and NH3 polymerization present no major differences and form a felt of interlocking collagen fibres with discrete filamentous networks associated with these fibres; and c) matrices polymerized by NH3 and crosslinked with glutaraldehyde form a dense meshwork of filaments with a more occasional distribution of fibrils associated with filaments or dense "amorphous" aggregates. The level of supramolecular reassemblage of solubilized collagen may be, therefore, a significant factor in determining urothelial cell growth and differentiation on collagen matrices.

Animals↗
PubMed1983

Cell surface properties of high- and low-metastatic cell lines selected from a spontaneous mouse lung carcinoma.

The surface oligosaccharide residues, glycoproteins and sialyl components of CMT64 lung carcinoma cells and high-metastatic sublines CMT167 and CMT181 have been studied in culture. (1) The total cellular sialic acid content did not differ appreciably between the three lines. However, the accessibility of surface sialyl groups, measured by metabolic incorporation of [3H]NAcmannosamine followed by neuraminidase hydrolysis, was decreased from 42% in CMT64 to 25% hydrolyzed in CMT181. (2) The major plasma membrane glycoproteins of the lines were radiolabelled by lactoperoxidase iodination, metabolic incorporation of [3H]fucose or labelling in the terminal sialyl residues by the NaIO4-NaB[3H]4 method and the labelled glycoproteins were analyzed by two-dimensional gel electrophoresis. Each labelling technique identified a complex pattern of glycoproteins including a prominently labelled group of high-molecular-weight acidic sialoglycoproteins: GP200/4.9-5.1 (apparent molecular weight X 10(-3)/pl of iodoprotein); GP150/5.1-5.6; GP130/5.0-5.6; GP110/5.0; GP100/4.8 and GP100/5.0-5.4. (3) The neuraminidase-susceptible glycoproteins on CMT64 and CMT181 were identified in the isoelectric focusing separation of the two-dimensional gel separation by the charge difference caused by desialylation. The glycoproteins most susceptible to neuraminidase were the high-molecular-weight acidic glycoproteins which showed marked charge heterogeneity: GP150/5.1-5.6, GP130/5.0-5.6; GP100/5.0-5.4 and GP100/4.8. (4) Using these procedures we did not detect modifications between CMT181 and CMT64 and we conclude that the cultured cells of the sublines do not display marked surface glycoprotein alterations that reflect their enhanced spontaneous metastatic potential.

Animals↗
PubMed1983

Identification of exposed surface glycoproteins of four human bladder carcinoma cell lines.

Three cell surface protein-specific methods were used to radiolabel the major glycoproteins of four human bladder carcinoma cell lines: The well-differentiated lines RT112 and TR4 and more anaplastic lines T24 and EJ. Five acidic glycoproteins iodinated in all lines by the lactoperoxidase/125I method were designated CP-175/5.8-6.0 (apparent molecular weight X 10(-3)/pl of iodoprotein), GP-155/5.0-5.3, GP-145/4.9-5.2, GP-130/4.8-5.5 and GP-110/4.9-5.3. Another iodinated glycoprotein, GP-200/5.5-6.0, was prominently labelled in RT112 and RT4 but was not detected in T24 or EJ. GP-200 as well as GP-175, GP-155 and GP-145 were not detected by the galactose oxidase/NaB(3H)4 method and were poorly labelled by the neuraminidase-galactose oxidase/NaB(3H)4 and NaIO4/NaB(3H)4 labelling methods. The major sialogalactoproteins identified in the four lines by the neuraminidase-galactose oxidase/NaB(3H)4 and NaIO4/NaB(3H)4 methods were GP-130, and a duplet of GP-90 and GP-80 which were poorly iodinated by lactoperoxidase/125I. The galactose oxidase/NaB(3H)4 reaction was increased by between 4- and 10-fold and many additional glycoproteins were labelled after neuraminidase treatment, indicating that the cell surface galactose and N-acetylgalactosamine residues of glycoproteins are highly sialylated. In cell lines RT112 and RT4 there was prominent labelling of very high molecular weight sialogalactoconjugates that was not present in extracts of T24 and EJ.

Cell Line↗
PubMed1981

Carcinoma of the perianal gland and associated structures in 1,2-dimethylhydrazine treated mice.

Male C57BL/Icrf alpha t mice receiving long courses of weekly subcutaneous injections of 8.25 or 12.5 mg/kg, 1,2-dimethylhydrazine (DMH) developed perianal carcinomas as well as tumours at other sites. Tumours of the perianal gland or its associated hair root sheath and overlying skin included sebaceous gland adenocarcinomas, often with squamous metaplasia, analogous to those in the rat ear, and dysplasia, polyp formation and squamous cell carcinomas (SCC). Of 152 mice treated, 88 remained after 30 injections, and 10 out of a total of 14 tumours developed after 30 treatments. Perianal SCC without definite perianal gland association developed in 2 other animals.

Anal Gland Neoplasms↗
PubMed1981

The effects of age on tumour induction in C57BL mice using 1,2-dimethylhydrazine.

Adult (6-8 months) and aged (22-24 months) male C57BL/Icrf at mice were given 8.25 or 12.25 mg 1,2-dimethylhydrazine(DMH)/kg weekly s.c. and groups of 4 animals autopsied after 8, 12, 16, 20, 24 or 36 treatments. No age difference was found in the development or appearance of large bowel tumours. Abnormal glands, not found less than 150 mg DMH/kg, preceded polyps and adenocarcinomas which occurred greater than 300 mg/kg. Treated mice showed hepatic cell damage, and biliary hyperplasia developed after 20 weeks. Seven haemangiosarcomas of the urogenital tract and 2 perianal carcinomas occurred in 11 adult mice surviving greater than 24 weeks at 12.5 mg/kg: no haemangiosarcomas but 1 perianal carcinoma occurred in 4 remaining mice in the equivalent aged group. Ileal amyloid was present in the old mice.

Age Factors↗
PubMed1981

Localization of organ-specific antigens in mouse lung by light and electron microscopy.

Rabbit antisera were raised against whole homogenate and a saline soluble fraction of C57BL mouse lung. After absorption with other mouse organs, both antisera gave specific staining of bronchiolar epithelial and single alveolar cells, using the indirect immunofluorescence and indirect immunoperoxidase techniques on both acetic-alcohol-fixed paraffin-embedded and unfixed frozen 5 micrometer sections. Improved resolution by light microscopy was achieved with 1 micrometer sections of formaldehyde-fixed Araldite-embedded material stained by an indirect immunoperoxidase method after the Araldite had been treated with saturated alcoholic NaOH for 5 min. Clara cells and type II pneumocytes were identifiable as sites of the lung-specific immune reaction. At the electron microscopic level the reaction was localized over the granules of bronchiolar Clara cells. The lamellar bodies of type II pneumocytes were extracted in the ultrathin sections and no immune reaction was observed.

Animals↗
PubMed1981

Ultrastructural studies on chromatin digestion by micrococcal nuclease in the presence of polyamines.

Nuclei purified from C57BL mouse submandibular salivary gland were treated with a range of micrococcal nuclease concentrations and times of treatment (from 0.5 unit for 2.5 min to 50 units for 30 min) in the presence of polyamines. About 50% of the chromatin was solubilized initially but with prolonged digestion this chromatin became insoluble again. Electron microscopy showed destruction of the finely dispersed chromatin with mild digestion, followed by aggregation of chromatin with more vigorous digestion. The early disappearance of finely dispersed chromatin filaments was not accompanied by preferential solubilization of chromatin associated with RNA polymerase II (euchromatin). These data suggest that the polyamines markedly reduce the susceptibility of euchromatin to micrococcal nuclease digestion.

Animals↗
PubMed1980

Digestion by micrococcal nuclease of mouse submandibular-salivary-gland chromatin.

Nucleic prepared from mouse submandibular salivary gland show marked fragility during isolation. Hwever, intact nuclei relatively free from cytoplasmic contamination were obtained by homogenization in buffers containing 0.88 M-sucrose, Ca2+, spermine, spermidine and the proteinase inhibitor aprotinin, followed by centrifugation through 2.2 M-sucrose. The kinetics of digestion by the micrococcal nuclease of chromatin in these nuclei are similar to those of chromatin from mouse liver nuclei. Base-pair size analysis of the solubilized DNA from both organs shows a stable high-molecular weight species of chromatin, which is further digested to mononucleosome and subnucleosome species. With extensive digestion the chromatin becomes insoluble. The mononucleosomes produced from salivary-gland chromatin after the inhibition of endogenous proteinase activity exhibit an s20,w value of 11S and contain histones H1, H2A, H2B, H3 and H4.

Animals↗
PubMed1979

Problems associated with the development of a colony of aged mice for experimental purposes.

Old animals are not commercially available in the U.K. The following problems associated with the supply of aged C57BL mice to an experimental group over a period of 12 years are discussed: the choice of animal, initial assumptions about management, and husbandry and its change with time. Finally, the recurrent problems which remain if valuable animals are to be kept disease-free yet available to experimentalists are listed.

Aging↗
PubMed1978

Cell surface coat of hamster fibroblasts.

The UHF fraction from NIL 8 hamster embryo fibroblasts contains the LETS protein and several other major proteins. It exhibits three enzymatic activities in significant amounts: 5'-nucleotidase, alkaline phosphatase, and galactosyl transferase. The latter two appear to be different from the membrane-bound enzymes. This fraction is heavily stained with ruthenium red, a dye specific for the cell coat in intact cells. A comparable fraction from hamster sarcoma virus-transformed cells exhibits a similar overall protein composition but lacks at least three major proteins, including the LETS protein. Compared to NIL 8 cells, the distribution of alkaline phosphatase in fractions from these cells is different, and the level of galactosyl transferase in the UHF is much reduced.

Alkaline Phosphatase↗