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Biomedical subjects

J Coll

Publications and source records attributed to J Coll.

At least 91 records · Page 5Linked to original sources
PubMed1986

v-mil induces autocrine growth and enhanced tumorigenicity in v-myc-transformed avian macrophages.

MH2, an avian retrovirus containing the v-myc and v-mil oncogenes, rapidly transforms chick hematopoietic cells in vitro. The transformed cells belong to the macrophage lineage and proliferate in the absence of exogenous growth factors. Here we analyze a series of MH2 deletion mutants and show that these two oncogenes together establish an autocrine growth system in which v-myc stimulates cell proliferation, while v-mil induces the production of chicken myelomonocytic growth factor (cMGF). We also demonstrate that these two oncogenes cooperate in vivo. MH2 efficiently induces monocytic leukemias and liver tumors, while deletion mutants lacking either a functional v-mil or v-myc do not.

Animals↗
PubMed1986

[Isolated aortic valve replacement in an advanced stage of cardiac failure. Results and prognostic study apropos of 71 cases].

Between January 1970 and December 1982, seventy-one patients in functional Stage IV of the NYHA classification underwent isolated aortic valve replacement for aortic incompetence (27 cases), aortic stenosis (18 cases) or mixed aortic valve disease (26 cases). Three haemodynamic criteria were chosen: left ventricular ejection fraction less than 40% (average 34 +/- 2%); arteriovenous difference greater than 6 volumes per 100 ml (average 6.7 +/- 0.2 vol.); left ventricular end diastolic pressure greater than 20 mmHg (average 26 +/- 1.3 mmHg). Analysis of the preoperative data defined the clinical profile of these patients: average cardiac index 2.2 +/- 0.07 l/min/m2; 75% had a cardiothoracic index greater than 0.50%; 61% had at least one conduction defect. The average Sokolow index was 50 +/- 2 mm. Twenty seven of the 71 patients died (36%); there were 7 early postoperative deaths (1st month) (10%), mainly due to ventricular arrhythmias (6 out of 7). There were 20 late deaths (31%) on average 52 +/- 8 months after surgery: 70% were of cardiac origin with a predominance of sudden deaths. There were no deaths in the group of patients operated after 1977, probably because of improved techniques of peroperative myocardial protection. The actuarial survival was 72% at 5 years and 63% at 10 years: long term survival was lower in aortic incompetence (25% at 10 years) compared with aortic stenosis (68%) and mixed aortic valve disease (78%). There was a significant relationship between long term survival and cardiothoracic ratio, ejection fraction, the duration of symptoms before surgery and the presence of atrioventricular or left bundle branch block.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1984

[Stimulation of cell division by Ehrlich carcinoma cell surface antibodies].

Some Ehrlich ascites cancer cells of the mouse show nuclear division as a response to cell surface signals. Antibodies to plasma membrane produce a membrane molecular redistribution, but only 25 per 100 proceed to nuclear division. This division is not associated to DNA synthesis, showing that the effect is produced in G0 phase cells originated from G2 phase cells.

Animals↗
PubMed1984

High stability hybrids producing monoclonal antibodies against human C-reactive protein.

This report shows how high stability hybrids producing monoclonal antibodies against human C-reactive protein were raised and selected. Monoclonal antibodies can be produced in large enough quantities through this method, to allow for the design and use of quantitative C-reactive protein determination on a clinical scale. This novel strategy consisted of the following: growing the hybrids and freezing them before cloning in order to assure stability and selecting the hybrids from those producing high titres in mouse ascite induction. Two monoclonal antibodies of high stability and great potential for large scale production have been developed in this manner. Production on a large scale of these monoclonal antibodies against human C-reactive protein can be useful both in clinical quantification and in physiological studies concerning its still unknown in vivo function.

Animals↗
PubMed1983

Two different types of transcription for the myelocytomatosis viruses MH2 and CMII.

The four avian defective leukemia retroviruses (DLVs) MC29, CMII, MH2 and OK10 all transform primarily macrophages in an in vitro bone marrow transformation assay, and contain specific nucleotide sequences closely related to the myc gene of MC29. These viruses were thought to express their oncogenic potential through a gag-myc fusion polyprotein, since fusion polyproteins were found in all tested cells transformed by MC29. We show here that MH2 virus does not conform to this model. Whereas MC29 produces only one mRNA detectable by RNA blotting in productively transformed cells, we reported recently that OK10 induced the synthesis of two myc-containing mRNAs, the smaller species being a spliced mRNA and a possible candidate for a transforming protein lacking gag determinants. However, the studies with OK10 were ambiguous because this virus produced also, in infected cells, a fusion protein containing gag, pol and myc determinants. We have therefore investigated the transcription pattern of the two other members of this group of viruses, namely CMII and MH2. Our results show that CMII resembles MC29 whereas MH2 produces, as OK10, two mRNAs containing myc-related sequences. However, unlike OK10, the MH2 fusion protein of 100 kd described previously cannot contain myc determinants and thus is likely to produce from its subgenomic mRNA a v-myc protein-lacking gag determinants. We thus conclude that the product of the v-myc oncogene is transforming with (MC29) or without (MH2) its fusion to gag determinants and that the multiple oncogenic spectrum is not basically affected since MH2 and MC29 both transform macrophages, fibroblasts and epithelial cells.

Avian Leukosis Virus↗
PubMed1983

The cellular oncogenes c-myc, c-myb and c-erb are transcribed in defined types of avian hematopoietic cells.

The possible role of normal chicken cellular sequences c-erb, c-myb and c-myc, together referred to as c-onc genes and related to the oncogenes of defective avian acute leukemia retroviruses (DLVs), was investigated by determining the accumulation of c-onc RNA in different avian cells an cell lines. Levels of c-myc and in some instances c-myb RNA are elevated in immature hematopoietic cells or cell lines from various lineages but more mature hematopoietic cells, as well as non-hematopoietic cells, contain only low levels. In contrast, the level of c-erb RNA is generally low, but high in a small number of normal bone marrow cells. The results indicate that the cellular homologues of the viral oncogenes are differentially expressed during hematopoiesis. They also indicate that the hypothesis that DLV target cells express their homologous c-onc genes might hold for c-erb, but is not valid in its simple form for c-myc and c-myb.

Animals↗
PubMed1982

Characterization of c-lil, a chicken cellular sequence associated with a stock of B77 avian sarcoma virus.

Using biochemical methods, we have shown that a new specific sequence, v-lil, is associated with a given stock of B77 avian sarcoma virus (clone 9). We prepared a DNA complementary to v-lil sequences, using substractive hybridizations, and investigated the properties of this sequence. v-lil has a genetic complexity of ca. 2,000 nucleotides and is not present in various stocks of avian sarcoma virus, avian leukosis virus, or defective leukemia virus. v-lil is not associated with B77 avian sarcoma virus isolated from the original tumor and thus has been acquired by in vitro passage of the virus on chicken embryo fibroblasts. A search for the origin of the v-lil sequence among the DNAs of different avian species has shown that a similar sequence, c-lil, is present in normal chicken DNA (1 to 2 copies per haploid genome). c-lil is not highly conserved but is present in the DNA of all chickens from the genus Gallus. The c-lil sequence is transcribed at a low level (1 to 3 copies per cell) in normal chicken embryo fibroblasts. The biological function, if any, of v-lil or its cellular equivalent has yet to be determined.

Animals↗
PubMed1982

[Circulating immune complexes in the serum of tumor patients].

The conditions for the detection of circulating immune complexes (CIC) were established by combination of polyethylene glycol precipitation with a nephelometric determination on the precipitate of endogenous C1q. The CIC precipitated from the sera of patients with breast carcinoma, malignant melanoma or autoimmune diseases were dissociated in SDS-beta-mercaptoethanol buffer and no differences were observed in the electrophoretic patterns os polyacrylamide gels allowing to characterize tumour specific antigens.

Antigen-Antibody Complex↗