Biomedical subjects

C H Cheung

Publications and source records attributed to C H Cheung.

3 recordsLinked to original sources

PubMed1978

Detection of viral-like cores from the urine of patients with genito-urinary malignancies.

Simultaneous detection assays on the core structures derived from the cerebrospinal fluid samples of patients with various types of central nervous system tumors have demonstrated the feasibility of this technique in detecting some of the diagnostic features of RNA tumor viruses. Similar assays done on urine samples from patients iwth various types of tumors in their genitourinary tracts have shown that of the 18 such samples from tumor patients, 15 or 83% were found to be positive. The control samples consisted of three from patients with benign prostatic hypertrophy and four from normal persons. None of these gave a positive reaction. [3H]DNA probes synthesized from the core structures from them hybridized readily to their corresponding polysomal RNAs but no to control tissues. The densities of particles from these samples have been found to be 1.168 g/ml for bladder carcinoma and 1.165 for prostatic carcinoma, the same densities as those found RNA tumor viruses.

Female↗

PubMed1977

Embryogeneic cell type, organ site sequence specificity in human cancers.

An extensive series of cross-hybridization studies were carried out with the DNA-RNA molecular hybridization technique. Molecular 70 S [3H]DNA probes synthesized from human central nervous system, gastrointestinal, pulmonary, and prostatic carcinomas were hybridized to cytoplasmic RNA's isolated from cancers of virtually all organ sites of the human body. Results indicated sequence homology between cancers of the same organ or cell type but not with cancers of different cell types. Thus cell types based on embryological origins determine the organ site specificity of the involved sequences. The designation of 70 S [3H]DNA denotes those [3H]DNA's that were copied off the template 70 S RNA, as distinguished from total [3H]DNA product, which includes all DNA's synthesized. It does not necessarily follow nor is it to be inferred that the 70 S [3H] DNA thus designated contains the full complement of the sequences found in the 70 S RNA template.

Base Sequence↗

PubMed1976

Biochemical evidences for ribonucleic acid viral-like characteristics in malignant diseases of gastrointestinal tract and lung in humans.

It has been demonstrated that malignant diseases of the gastrointestinal tract and lung in humans possess three characteristics invariably found in ribonucleic acid tumor viruses: the presence of a ribonucleic acid directed deoxyribonucleic acid polymerase, reverse transcriptase; a high molecular weight ribonucleic acid with a sedimentation coefficient of 70 Svedberg units, and particulate elements with densities of 1.16 to 1.18 grams per milliliter sucrose gradient. Twelve of 17 carcinomas of the colon, three of five carcinomas of the stomach, all three carcinomas of the rectum and seven of ten carcinomas of the lung displayed detectable evidence of these viral-like entities. None of the corresponding normal tissues had positive reactions.

Cell Transformation, Neoplastic↗