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Biomedical subjects

S Ryu

Publications and source records attributed to S Ryu.

144 records · Page 8Linked to original sources
PubMed1983

[Conditions suitable for chemotherapy of lung cancer].

The influence of several factors for response to Chemotherapy and survival was analysed in 310 patients with inoperable lung cancer who were treated by single or combination chemotherapy. In small cell lung cancer, survival was strongly affected by the results of induction chemotherapy, and combination chemotherapy with three or four drugs was most effective. In non-small cell lung cancer, performance status and body weight loss on admission were important factors for response to chemotherapy and survival. Combinations did not improve the response rate in non-small cell lung cancer.

Adenocarcinoma↗
PubMed1982

Biofeedback therapy for spastic dysphonia.

Spastic dysphonia is a disorder of phonation which is characterized by a strained, creaking, and choked vocal attack, a tense and squeezed voice sound. Spastic dysphonia in a functional voice disorder can be classified into two types from the viewpoint of activities of the extrinsic and intrinsic laryngeal muscle groups. A functional voice disorder pertaining to abnormal activities of the intrinsic and extrinsic laryngeal muscles results in spastic dysphonia. The adductor spastic dysphonia may be due to abnormal actions of the intrinsic laryngeal muscles as such is relieved by sectioning of the recurrent nerve, while spastic dysphonia mainly dealing with the extrinsic laryngeal muscles is relieved by relaxation on monitoring an electromyographic feedback system. Within 3 months we encountered two patients whose extrinsic laryngeal muscles were hyperactive on phonation. A trial on injection of lidocaine into extrinsic laryngeal muscles made their muscles relax. So, biofeedback therapy of relaxation was began using a monitoring system of EMG burst regarding to hypertonicity of the extrinsic laryngeal muscles. Normal vocal abilities were recovered using a biotrainer as a monitoring device of electromyographic feedback.

Adult↗
PubMed1979

Evaluation of tumor angiogenesis factor with the rabbit cornea model.

Sequential histopathological observations were made of the rabbit corneas after an implantation of viable and nonviable tumor cells in the corneal stroma. They showed a nonspecific localized interstitial keratitis accompanied by inflammatory cells and new capillaries. We could not observe any significant clinical or histopathological differences between the corneas containing live or dead tumor implants, or between those with different tumor types (i.e., retinoblastoma and melanoma). Some variation in the severity of the inflammatory response was observed in different animals with the same tumor. In all cases, the extent of the corneal neovascularization correlated with the degree of inflammation. However, in rabbits made immune-deficient by radiation, there was negligible inflammation and vascularization when tumor was implanted.

Angiogenesis Inducing Agents↗
PubMed1978

Synergistic combination therapy of 5-fluorouracil, vitamin A and cobalt-60 radiation upon head and neck tumors.

We have applied a triple combination of 5-fluorouracil (5FU), vitamin A and cobalt-60 radiation (FAR therapy) to clinical treatment of head and neck tumors since 1972. The treatment of 33 patients with cancer of larynx and 15 patients with hypopharyngeal or cervical esophageal cancer with FAR therapy during three years from 1972 to 1974 resulted in highly effective synergism in vivo, and the improved points of this therapy were presented.

Cobalt Radioisotopes↗
PubMedDate not supplied

Probing pores using elementary quantum mechanics.

The relaxation of polarized spins in a porous medium has been utilized as a probe of its structure. We note that the governing diffusion problem has a close parallel to that of a particle in a box, an elementary Quantum mechanics toy model. Following the spirits of "free electron" model, we use generic properties of the eigen spectrum to understand features common to a wide variety of pore geometry, consistent with large scale numerical simulations and experimental data.

Magnetic Resonance Spectroscopy↗
PubMedDate not supplied

Kinetics of the postinhibitory reactions of acetylcholinesterase poisoned by chiral isomalathion: a surprising nonreactivation induced by the RP stereoisomers.

Inhibitory (ki), spontaneous (k0), and oxime-mediated reactivation (k(oxime)) reaction kinetics for the four stereoisomers of isomalathion (SPRC,SPSC,RPRC, and RPSC) were determined against rat brain acetylcholinesterase (AChE). (SPRC)-Isomalathion was the most potent anticholinesterase agent and RPSC-isomalathion the least potent with racemic material approximately midway in activity. Following inhibition of rat brain AChE by (SPRC)- or (SPSC)-isomalathion, k0 and k(oxime) values were obtained that were comparable to (SP)-isoparathion methyl, indicating that the same mechanism of inhibition was shared, namely, formation of an O,S-dimethyl phosphorothiolated enzyme. Conversely, no appreciable reactivation occurred with or without oxime following inhibition of rat brain AChE by (RPSC)- or (RPRC)-isomalathion. This observation was not consistent with (RP)-isoparathion methyl, and a switch in inhibition mechanism to the loss of the thiomethyl moiety is suggested. The nonreactivation of rat brain AChE following inhibition by the (RP)-isomalathion stereoisomers is postulated to result from a mechanism involving either a beta-elimination of diethyl fumarate or displacement of the thiosuccinate moiety from the phosphate moiety.

Acetylcholinesterase↗
PubMedDate not supplied

Donor-specific unresponsiveness induced by intraportal grafting and FK506 in rat islet allografts: importance of low temperature culture and transplant site on induction and maintenance.

Previously we demonstrated prolongation of islet allograft survival in rat by administration of FK506 to the recipients. The purpose of the present study was to determine whether specific immune unresponsiveness had been induced and to determine the effects of low temperature culture of donor islets as well as the transplant site on the induction of immune unresponsiveness. At 90 days after transplantation, normoglycemic recipients bearing functional intrahepatic grafts were made diabetic again with streptozotocin (STZ) and donor specific or third party islets were transplanted either into the liver or beneath the kidney capsule. When fresh islets were used as donors in initial transplantation in conjunction with FK506, intrahepatic re-transplants of fresh islets from the donor-specific strain in the absence of FK506 maintained normoglycemia for more than 60 days, while third party transplants (n = 3) were rejected within 1 wk. In contrast to intrahepatic regrafts, all the renal subcapsular regrafts from the donor-specific strain (n = 3) were rejected with mean survival time of 12.7 +/- 6.4 days. When cultured (24 degrees C, 7 days) islets were used for initial transplantation in conjunction with FK506, re-transplants of fresh or cultured islets from the donor specific strain beneath the kidney capsule maintained normoglycemic in 3 out of 6 or all (n = 4) of the recipients, respectively. Cultured third party regrafts beneath the kidney capsule (n = 2) were rejected at 9 days.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

Increased tumour response of a murine fibrosarcoma to low temperature hyperthermia and low dose rate brachytherapy.

The present animal tumour study was carried out to determine the effectiveness of low temperature hyperthermia combined with low dose rate radiation based on the cell culture studies of our laboratory and others that demonstrated a significant radiosensitization obtained by low temperature hyperthermia and low dose rate radiation. Well-oxygenated murine fibrosarcoma Meth-A tumours growing in Balb/c mice were treated with heat (41 degrees C tumour temperature) by immersion of the tumour-bearing leg in a waterbath concurrently with low dose rate radiation. Radiation was delivered using 192Ir interstitial implantation at absolute dose rates of 0.416-0.542 Gy/h. The effect of heat alone on tumour growth and normal tissue was minimal. Tumour growth delay following 30 Gy radiation was 4.9 days. Significant delay in tumour growth was observed with the addition of low temperature hyperthermia delivered concurrently. Enhancement in radiation response was seen with increasing duration of heat treatment; tumour growth delays were 9.5 days following 4 h heat (41 degrees C) treatment and 16 days following 6 h treatment. Three sessions of fractionated hyperthermia 4 h/day during the course of low dose-rate radiation significantly delayed tumour growth to 18.6 days. The results indicate that fractionated heat treatment in conjunction with low dose rate radiation has potential for improving tumour response without adversely affecting normal tissue reaction. This in vivo study represents an extension of the cell culture data and provides further radiobiological basis for the combined use of low temperature hyperthermia and low dose rate radiation.

Animals↗