[Carcinoembryonic antigen assay in serum and pleural effusion of pulmonary malignancies and benign lesions]

Levels of carcinoembryonic antigen(CEA)in the serum and pleural effusion in malignancies (65) and benign (25) of lung were determined. There are 20 cases of adenocarcinoma, 16 undifferentiated carcinoma, 7 squamous cell carcinoma, 4 alveolar carcinoma, 12 unclassified carcinoma, 1 polymorphous adenoma, 1 mesothelioma, 1 thymoma, 1 metastatic cancer from kidney and 2 metastatic breast cancer. In the benign lesions, there are 20 tuberculosis, 2 heart failure, 1 pneumonia, 1 empyema and 1 cirrhosis. The mean of the CEA level in the serum of lung cancer group was 12.63 ng/ml as compared with that of the tuberculosis group, 3.01 ng/ml (P less than 0.01). The level of CEA in pleural fluid in the lung cancer group was 57.30 ng/ml as compared with that of tuberculosis group, 5.55 ng/ml (P less than 0.01). The content of CEA in the serum and pleural fluid in lung cancer group was remarkably different (P less than 0.01). CEA level in the serum of adenocarcinoma is the highest (mean 15.51 ng/ml). If we set 5 ng/ml as the margin of normal CEA level in serum, the positive rate for cancer would be 54.2%. It is suggested that the margin of CEA normal value be set at 10 ng/ml for the pleural fluid. Higher readings may imply cancer.

Analysis of mouse major urinary protein genes: variation between the exonic sequences of group 1 genes and a comparison with an active gene out with group 1 both suggest that gene conversion has occurred between MUP genes

Here we compare the exonic sequences of four Group 1 mouse major urinary protein (MUP) genes and four Group 1 cDNA sequences. These define seven different nucleotide sequences which differ from each other by 0.35% of bases on average, and which would code for seven different MUP proteins that could probably be resolved physically into at least five classes. The sequences differ at 13 nucleotide positions and at six codons, and although they are closely related their descent cannot be described by a simple series of duplications. We also describe the sequence of another liver cDNA (pMUP15) which has diverged from the Group 1 consensus sequence in 14.6% of bases. The divergence is much greater over exons 1-3 than over exons 4-6, suggesting that an ancestral gene conversion event has occurred. pMUP15 also differs from the Group 1 genes in having a longer signal peptide sequence and a different splice configuration between exons 6 and 7. Unlike the Group 1 sequences, pMUP15 contains a potential N-linked glycosylation site. Other published work has shown that a shorter cDNA clone which is identical over their common sequence to pMUP15 codes for MUP proteins that are unusually large in size and acidic in pI. We show here that mouse urine does indeed contain a glycosylated MUP protein with those properties, presumably the product of the gene that corresponds to pMUP15.

Synthesis of simian virus 40 chromosomes in nuclear extracts from dihydroxyanthraquinone-treated cells

The effect of dihydroxyanthraquinone (DHAQ), a new antitumor drug, on mammalian chromosome replication was investigated using simian virus 40 (SV40) as a model system. The maximum effect of inhibition on viral DNA synthesis was observed within 30-40 min after the addition of the drug. The extent of inhibition of viral DNA synthesis appeared to be directly related to the number of viral replicons which interact with DHAQ molecules in vivo. No apparent strand breakage of SV40 DNA was observed in infected cells treated with DHAQ ranging from 0.3 to 10 microM. However, strand breakage was induced upon cell lysis presumably by released nuclease. Repair of the damaged SV40 chromosomes in vitro resulted in the synthesis of completed supercoiled SV40 DNA. This repair synthesis was mostly confined to the region containing the replication origin of SV40 DNA as judged by the digestion of DNA with restriction endonucleases HindII and HindIII. Since SV40 DNA sequences close to the origin of replication are not complexed with histones to form a nucleosome structure, the results suggested that DHAQ may disturb chromosome structure by interacting preferentially to the nucleosome-free regions and causing the aberrant gene duplication and expression.