Unusual retention of introns in CD44 gene transcripts in bladder cancer provides new diagnostic and clinical oncological opportunities.

Increased and disorganised expression of CD44 variant exons has been demonstrated in biopsy samples of several types of human malignancy by many groups. This abnormality can be used to detect exfoliated tumour cells in the urine of bladder cancer patients. The present report demonstrates that the deranged activity of this gene in neoplasia also results in the accumulation of immature mRNA transcripts containing non-coding sequences (introns) from this gene in cancer tissues and cells. There is simultaneous overexpression of a newly identified 437 bp exon (coding sequence) located in the variably active region of the gene and of many abnormal variant exon combinations. This is the first report describing the specific retention of introns in gene transcripts in clinical diagnostic samples of tumour tissues and cells. The phenomenon was seen repeatedly in samples from cancer patients and in a cancer cell line, and thus could form the basis for a unique new and specific method of cancer diagnosis.

Transfection of metastatic capability with total genomic DNA from human and mouse metastatic tumour cell lines.

From a large series of experiments involving transfer of high molecular weight total genomic DNA from highly metastatic human and mouse tumour cell lines to other mouse tumour cell lines we have derived a few cell lines with greatly augmented metastatic properties. In one of these experiments the transfected cell line (designated AH8 Test) not only colonised the lungs but also formed secondary tumour colonies in several extrapulmonary sites including the skin, skeletal muscles, bone, liver diaphragm, spleen and heart. There were no qualitative and quantitative effects of this magnitude when we used DNA from several non-metastatic or non-tumourigenic sources. Secondary transfection of metastatic capability with DNA obtained from a metastasis formed by one of the primary transfectant lines (AH8 Test) has also been accomplished. Concomitant transfer of human DNA through both transfection cycles in this experiment was confirmed by a variety of methods including Southern blot analysis, in situ hybridisation and polymerase chain reaction (PCR) amplification of DNA using primers recognising human-specific Alu repeat sequences. The findings offer opportunities for the isolation of sequences programming metastatic behaviour and we have cloned and sequenced a fragment of human DNA, which has not been previously characterised, from the transfected cells.

The ras oncogene and tumour metastasis: observations on murine cells transfected with activated human c-Ha-ras.

Transfection of cells with cloned genes or total genomic DNA offers a means for studying aspects of neoplastic behaviour. We have used this method to examine whether incorporation of the cloned 6.6-kilobase (kb) fragment of DNA containing the mutant c-Ha-ras human oncogene can confer metastatic capability on murine NIH 3T3 cells. Cells co-transfected with the mutated ras gene and the neomycin resistance marker pSV2neo were selected by culture in neomycin. On subcutaneous inoculation into MF 1 nude mice, these cells proved to be tumourigenic with short latent periods (approximately 14 days)--nude mice were used to circumvent immunological rejection of the mouse cells expressing the product of the human oncogene. Transfectants were capable of lung colonisation after intravenous injection, but there was no evidence of spontaneous metastasis at autopsy, or on histological examination of the lungs and other organs, 90 days after inoculation. Incorporation of the transfected oncogene was confirmed by Southern blotting and its expression by dot-blot hybridisation and immunoprecipitation. The results in this experimental system indicate that transfection of a mutated human ras oncogene into non-neoplastic 3T3 cells can confer part of the metastatic phenotype, namely lung colonisation, but is not by itself sufficient to induce spontaneous metastatic behaviour.

Dysentery in calves caused by an atypical strain of Escherichia coli (S102-9).

Dysentery lasting 4-8 days was produced in five 4-day-old colostrum-fed calves, after inoculation with an atypical strain of Escherichia coli S102-9; peak excretion of S102-9 occurred during the period of dysentery. Two calves were killed when clinical signs were most severe and bacteria were seen attached to the surfaces of enterocytes in the large intestine; microscopic lesions were seen in these areas. The lesions were identical to those previously reported in a natural outbreak of dysentery in calves, from which E. coli S102-9 was isolated, and to those seen in gnotobiotic calves experimentally infected with S102-9. Reinfection of the three surviving calves 16-20 days later with S102-9 and primary infection of two calves aged 24 and 51 days did not cause dysentery. Four of 659 coliforms isolated from field outbreaks of calf diarrhoea resembled the atypical strain S102-9. These four isolates and S102-9 did not produce heat-stable enterotoxin, but all produced a toxin cytopathic for Vero and HeLa cells. Two of the four isolates were inoculated alone into 4-day-old gnotobiotic calves deprived of colostrum; neither calf developed dysentery but microscopic lesions identical to those produced by S102-9 were detected in the large intestines of both animals.

Culture of respiratory syncytial virus infected diploid bovine nasal mucosa cells on cytodex 3 microcarriers.

In preliminary studies, a system for the propagation of respiratory syncytial virus (RSV) using cytodex 3 microcarriers was established. Optimal growth conditions were defined in culture to be a microcarrier concentration of 1.5 g/L with a cell inoculum density of 4 X 10(4) cells/ml tissue culture medium. Under these conditions growth coefficients were 3-fold greater in microcarriers when compared to conventional monolayer culture in roux culture flasks. Maximum yield of virus antigen was achieved after 8 days culture.

Cytotoxic lymphocytes in the lungs of mice infected with respiratory syncytial virus.

Mice infected with respiratory syncytial virus (RSV) developed cytotoxic lymphocytes in the lungs, which lysed RSV-infected, but not uninfected cells. Cytotoxic activity was greatest 7 to 9 days after infection, was virus-specific, MHC-restricted and abolished by treatment of lymphocytes with anti-Thy 1.2 or with anti-Lyt 2.2 sera and complement. There was a close temporal relationship between the appearance of these cytotoxic lymphocytes in the lung and clearance of virus. In contrast, RSV persisted in the lungs of athymic (nude) mice and such animals failed to develop RSV-specific cytotoxic lymphocytes. Thus, cytotoxic T-cells may have an important role in recovery from RSV infection.

The effect of sodium sulphacetamide and sodium mandelate in brilliant green agar on the growth of salmonellas.

An assessment was made of the ability of 425 isolates of salmonellas, belonging to 54 serotypes, to grow on seven selective media. Several isolates of Salmonella dublin and Salm. paratyphi B failed to grow on brilliant green agar supplemented with sodium sulphacetamide and sodium mandelate. On this medium the colonies of 30 isolates which were able to grow were extremely small after 20 h incubation, and consequently their recognition was difficult. The sodium sulphacetamide was responsible for the reduction in colony size.