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Biomedical subjects

S C Chang

Publications and source records attributed to S C Chang.

At least 343 records · Page 19Linked to original sources
PubMed1978

Dose response in radiotherapy for glottic carcinoma.

All consecutive patients with glottic squamous cell carcinoma treated primarily by radiotherapy from 1965 through 1974 have been analyzed to reveal response of the primary tumor in relation to the dose. This study appears to indicate presence of dose response for all stages of the primary lesions (T) of the glottic carcinoma except for the smallest ones namely TIS, T1a and T1b. The total number of advanced tumors is small and selected. But they tend to indicate presence of dose response. Out of 15 selected patients with T3 and T4 glottic tumors, 5 (33%) had attained local control by primary radiotherapy; two had distant metastasis at onset of therapy, while 5 (33%) needed salvage surgery for control of the residual or recurrent disease. The ultimate success rate is 66% (10 out of 15) for the patients with advanced tumors treated with a conservative approach. An ongoing study indicates similar, if not better preliminary results with high dose radiotherapy.

Adult↗
PubMed1978

The psychology of consciousness.

All psychologic phenomena occur in consciousness. However, "consciousness" has two meanings: the faculty and the content of awareness. Traditional psychologies have largely concerned themselves with the content, neglecting the problem of the faculty, thus, limiting our understanding of human psyche. Study of meditation is a viable approach to the exploration of both meanings of consciousness. Meditation aims at a "cleansing" of the mind to reach, thereby, a content-free and conflict-free state--pure consciousness.

Awareness↗
PubMed1978

Oncologic research and computerized data retrieval.

A computer-based data retrieval system for clinical research in oncology is described. The system has been designed to enable busy clinicians to retrieve and analyze data directly without major involvement of a computer specialist. The system uses texts similar to those in daily practice. In most situations no code is printed. The other important feature of the system is its ability to analyze clinical data in the form of tables, frequency distribution, etc. It may also furnish actuarial characteristics of the total population or subpopulations. Mathematical functions are calculated easily. Amendments and updating are simple enabling follow-up data to be incorporated. The system is under use for about 2 years and appears to be a versatile tool in the field of clinical research.

Clinical Trials as Topic↗
PubMed1977

Chlamydiae (with phages), mycoplasmas, and richettsiae in Chesapeake Bay bivalves.

Intracytoplasmic chlamydia-like organisms, some with phages, rickettsia-like organisms, and mycoplasma-like organisms have been found in clams and oysters from the Chesapeake Bay area by electron microscopy. None of these organisms have been previously detected in mollusks, nor have phages been previously observed in Chlamydia sp.

Animals↗
PubMed1976

On the inhibitory activity of 4-vinyl analogues of pyridoxal: enzyme and cell culture studies.

Analogues of pyridoxal and of pyridoxal phosphate in which the 4-CHO group is replaced with CH = CH2 were synthesized and were found to be potent inhibitors of pyridoxal kinase and pyridoxine phosphate oxidase of rat liver. They also inhibited the growth of mouse Sarcoma 180 and mammary adenocarcinoma TA3 in cell culture. Saturation of the vinyl double bond, replacement of the 5-CH2OH with methyl, methylation of the phenolic hydroxyl, or conversion to the N-oxide resulted in diminution or loss of all these activities. Similarly, the introduction of a beta-methyl group into the vinyl analogues of pyridoxal reduced all these inhibitory activities. The 4-vinyl anatogue of pyridoxal was shown to be a substrate of pyridoxal kinase and the product a potent inhibitor of pyridoxine oxidase, competing with pyridoxal phosphate. The affinity of this phosphorylated pyridoxal analogue to some apoenzymes varied greatly, indicating striking differences among the cofactor binding sites of these enzymes. The growth inhibitory effects of these analogues on cells in culture correlated well with their effects on pyridoxal kinase and pyridoxine phosphate oxidase in cell-free systems.

Animals↗
PubMed1976

Infection of armadillos with Mycobacterium leprae. Ultrastructural studies of peripheral nerve.

Peripheral nerves of armadillos were studied 16 to 30 months after intradermal or intravenous inoculation with Mycobacterium leprae. Numerous bacilli were found within macrophages, Schwann cells, and perineurial cells; endothelial cells, pericytes and fibroblasts were involved as well. The bacilli were characteristically contained in membrane-limited vacuoles that were interpreted as being phagosomes. Some of the phagosomes contained granular, membranous, and vesicular debris considered to be bacillary degradation products, suggesting that lysosomal activity was present within the phagosomes. Multivesicular bodies, a few of which contained bacilli, were abundant in macrophages and perineurial cells. An unusual proliferation of irregular tubulovesicular profiles was noted, especially in Schwann and perineurial cell cytoplasm, surrounding and within phagosomes containing bacilli. The pattern of cellular involvement of neural structures with M leprae was similar to that observed in lepromatous leprous neuritis in humans.

Animals↗
PubMed1976

Time study of effects of pregnant mare's serum gonadotropin on surface characteristics of granulosa cells in rat ovaries.

A single injection of pregnant mare's serum gonadotropin (PMSG) into immature female rats was used to stimulate graafian follicle growth. The surface of granulosa cells in the growing follicles was examined at 12-hour intervals for 72 hours by scanning electron microscopy. Between 24 and 36 hours after injection of PMSG, microvillous processes appeared on the surface of the cells. These villous processes became fully developed at 48 hours and remained for at least 72 hours after PMSG injection. The significance of this PMSG-induced microvilli formation on granulosa cells is discussed.

Animals↗
PubMed1974

Morita therapy.

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Adult↗