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Biomedical subjects

C S Han

Publications and source records attributed to C S Han.

7 recordsLinked to original sources
PubMed1992

Vascularized bone transfer.

We evaluated the results of reconstruction of a skeletal defect with use of a vascularized bone graft from the iliac crest or fibula in 160 patients who had been managed consecutively between 1979 and 1989. The indications for the procedure were a skeletal defect including non-union, resulting from resection of a tumor; traumatic bone loss; osteomyelitis; or a congenital anomaly. The average duration of follow-up was forty-two months (range, twelve to 112 months). For the entire series, the rate of union after the primary procedure was 61 per cent and the over-all rate at the latest follow-up examination (including the patients who had a secondary procedure) was 81 per cent. In a subgroup of seventy-six patients who had union after the primary procedure and did not have additional treatment, the average interval until union was six months and the average interval until full activity was sixteen months. The results were more favorable for the patients who had had reconstruction for resection of a tumor (of sixty-nine patients, fifty-six had union), for a congenital anomaly (of six patients, five had union), or for a non-union without infection (of twenty-five patients, twenty-three had union). The results were less satisfactory for patients who had had the reconstruction for bone loss due to osteomyelitis (of sixty patients, forty-six had union). Our data suggest that vascularized bone transfer for the reconstruction of large skeletal defects is a valuable procedure in appropriately selected patients.

Adolescent↗
PubMed1991

Giant cell tumor of the scapula associated with secondary aneurysmal bone cyst.

Giant cell tumors are distinctive neoplasms characterized by a profusion of multinucleate giant cells scattered throughout a stroma of mononuclear cells. Most giant cell tumors are found at the epiphyses of long bones, especially around the knee joint. Flat bone involvement is rare. However, a case of giant cell tumor with secondary aneurysmal bone cyst was encountered at the scapula of a 25-year-old man. Since the occurrence of a giant cell tumor with secondary aneurysmal bone cyst on flat bones (i.e., the scapula) is extremely rare, the above-mentioned case is worthy of reporting.

Adult↗
PubMed1985

Ascorbic acid: an endogenous inhibitor of isolated Na+,K+-ATPase.

During attempts to isolate and identify an endogenous ligand for the glycoside binding sites on Na+,K+-ATPase, bovine adrenal glands were found to contain a potent inhibitor of isolated Na+,K+-ATPase. The inhibitory principle was extracted from adrenal cortex, following homogenization in NaHCO3 solution and separation on a Sephadex G-10 column. The active principle was recovered from a fraction which eluted from the column after the 3H2O peak. The extract inhibited isolated Na+,K+-ATPase and the specific [3H]ouabain binding reaction. Sensitivity of the enzyme to the inhibitory action of the extract was species and tissue dependent; however, the pattern and the magnitude of the sensitivity were different from those of the digitalis glycosides. Moreover, the inhibitory principle failed to inhibit sodium pump activity, estimated from ouabain inhibitable 86Rb+ uptake by guinea pig brain slices. The activity of the extract to inhibit isolated Na+,K+-ATPase was stable under acidic condition but was lost rapidly at neutral pH, and could be eliminated by EDTA. In an acidic medium, the inhibitory principle had an absorption maximum at 244 nm which shifted to 264 nm and decayed rapidly at neutral pH. By using mass spectrometry, the principle was identified to be ascorbic acid, which has been shown previously to inhibit isolated Na+,K+-ATPase under appropriate conditions. Because ascorbic acid was incapable of inhibiting the sodium pump in intact cells, this inhibitor of the isolated enzyme does not appear to be the endogenous ligand which regulates sodium pump activity in vivo.

Adrenal Glands↗
PubMed1979

The role of central 5-hydroxytryptamine in acupuncture analgesia.

The role played by central 5-hydroxytryptamine (5-HT) in acupuncture analgesia (AA) has been studied in rats with the tail-flick response as the antinociceptive test. The analgesic effect of acupuncture can be enhanced or lowered by the increment or the decrement of the 5-HT level in the CNS. Furthermore, the turnover rate of 5-HT in the CNS has been found to be greatly facilitated during the period of acupuncture. The results imply that 5-HT in the CNS may be one of the most important neurochemical agents mediating AA.

5,6-Dihydroxytryptamine↗
PubMed1976

Effects of alkali metal cations on phospho-enzyme levels and [3H] ouabain binding to (Na+ + K+)-ATPase.

The effects of several alkali metal cations on the relationship between steady state phospho-enzyme levels and initial velocity and equilibrium levels of [3H]-ouabain binding to (Na+ + K+)-ATPase (ATP phosphohydrolase EC 3.6.1.3.) were examined. Only Na+ increased both phospho-enzyme and [3H] ouabain binding levels above those observed in the presence of Mg2+ alone. While Na+ stimulated phosphorylation with an apparent Km of about 1 mM, its stimulation of [3H] ouabain binding was biphasic, the lower Km for stimulation corresponding to the Km for formation of phospho-enzyme. Among the other alkali metal cations, potassium, rubidium and lithium were at least eight times more effect in reducing phospho-enzyme levels than in reducing [3H] ouabain binding. This discrepancy is not due to the stability of the enzyme-ouabain complex, nor to any action on the rates of formation or dissociation of the enzyme-ouabain complex. The data thus suggest that [3H] ouabain interacts with the K+, Rb+ or Li+ -enzyme complexes. For Li+, this hypothesis is further supported by the observation that Li+ can cirectly increase the equilibrium level of [3H] ouabain binding to this enzyme under certain conditions.

Adenosine Triphosphatases↗