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H Feng

Publications and source records attributed to H Feng.

2 recordsLinked to original sources

CT-guided stereotactic injection of radionuclide for treatment of brain tumors.

The authors report on 40 brain tumor patients treated with CT-guided stereotactic injection of 198Au and 32P. Among the 40 cases were astrocytoma in 23 cases, craniopharyngioma in 9, meningioma in 4, pituitary adenoma in 2, and pinealoma and metastatic carcinoma each in 1 case. The tumors were all located in deep or important areas of the brain which were difficult to deal with by conventional operation. 62 injections of colloidal isotopes were performed, and all were successful. No major adverse effects or complications occurred on follow-up of 6-12 months, 28 patients were improved in their clinical symptoms, and CT scanning showed that the tumor sizes were diminished. The effective rate is 70%.

Adenoma

Endplates after esterase inactivation in vivo: correlation between esterase concentration, functional response and fine structure.

Mouse sternomastoid muscles were incubated with diisopropylfluorophosphate (DFP) in vivo, and the time course of recovery was studied using histochemistry, EM autoradiography and physiology. We found that: (1) the ability of the muscle to sustain tetanus in response to nerve stimulation is eliminated when the esterases at the neuromuscular junctions are saturated with DFP. This ability is regained partially when less than 10% of the DFP-binding sites have recovered. (2) There is a positive correlation between the frequency of stimulation at which the tetanic response can be maintained and the extent of acetylcholinesterase (AChE) recovery. (3) Tetanic responses at fusion frequency (about 100 Hz) appear indistinguishable from controls with only about 25% of normal AChE. (4) Butyrylcholinesterase (BuChE) possibly of Schwann cell origin recovers more rapidly than does AChE. (5) The muscle shows fine structural changes involving Z band dissolution and the breakdown of sarcoplasmic reticulum within hours after esterase inactivation. (6) This myopathy reaches a peak at three days after esterase inactivation and is almost fully recovered by two weeks. (7) It can be eliminated if, at the time of esterase inactivation, the nerve is cut or the acetylcholine receptors at the endplate are inactivated by alpha-bungarotoxin. We suggest that the myopathy, seen after DFP, is mediated by Ca2+ fluxes due to prolonged action of acetylcholine (ACh) in the absence of esterases.

Acetylcholinesterase