Search PubMed⌕ Search

Biomedical subjects

R Y Kim

Publications and source records attributed to R Y Kim.

At least 73 records · Page 4Linked to original sources
PubMed1992

Treatment of recurrent head and neck cancer with 5-fluorouracil, hydroxyurea, and reirradiation.

Head and neck cancer locally recurrent after previous irradiation and surgery presents a difficult management problem. Conventional treatment alternatives include chemotherapy, reirradiation with interstitial implant, and hyperthermia. Reirradiation with external beam is generally not considered because of previous high radiation dose and limited tissue tolerance. In this study, 21 patients with recurrent and previously irradiated head and neck cancer were treated in a Phase I-II fashion. Patients received 5 days of 5-fluorouracil, 300 mg/m2/day IV bolus, Hydroxyurea 1.5 or 2 g/day by mouth and external beam radiation therapy every 2 weeks for up to four courses. Of 20 evaluable patients, 9 have attained a complete response (CR) and 6 a partial response (PR). Fifteen patients completed all planned therapy, eight on time, seven patients with delays. With a median follow-up of 7 months, 13 patients are alive, 7 disease-free (3 after salvage surgery) and 6 with recurrence. Eight patients have died. The 1-year survival is 56%. Treatment toxicity was mainly neutropenia. No major early or late radiation related side effects have been observed at a median follow-up of 7 months. Neither previous radiation dose, time since first radiation, prior chemotherapy, or site of recurrence was predictive of response or treatment tolerance. Patients with a performance status of at least 80 had a significant higher CR rate, with 7/10 patients in this group, as compared to 2/10 patients in patients with a performance status less than 80, achieving a CR. Reirradiation with 5-fluorouracil and hydroxyurea is a well tolerated outpatient treatment program for patients with recurrent and previous irradiated head and neck cancer that produces a high response rate and can provide significant palliation of symptoms.

Adult↗
PubMed1992

A phase I study of high-dose cisplatin, prolonged infusion 5-fluorouracil, and concomitant conventional fraction radiation therapy in patients with inoperable squamous cell carcinoma of the head and neck.

Cisplatin (CDDP) and 5-fluorouracil (5-FU) have been used alone, in combination, and in various doses and sequences with radiation therapy in attempts to improve local control and survival of patients with advanced head and neck cancer. This study was undertaken to determine the toxicity and maximum tolerated dose of high-dose CDDP plus prolonged infusion 5-FU with concomitant conventional radiation therapy. Twenty-two patients with inoperable Stage III and IV squamous cell cancer were treated with CDDP (30 or 35 mg/m2 for 5 days every 4 weeks for three courses) and 5-FU (200 or 300 mg/m2 per day continuous i.v. infusion for 12 weeks) with concomitant conventional radiation therapy. This aggressive treatment regimen is accompanied by severe mucositis, myelosuppression, and chronic neuropathy. CDDP, 35 mg/m2/day x 5, and 200 mg/m2/day of 5-FU infused over 12 weeks were identified as potential doses for future Phase II studies.

Adult↗
PubMed1992

Early-stage glottic cancer: importance of dose fractionation in radiation therapy.

The treatment results in 85 patients with T1N0M0 squamous cell carcinoma of the glottic larynx who were treated with primary radiation therapy were reviewed to analyze for local control. After a minimum follow-up period of 2 years, 13 patients had local recurrence of disease, which yielded a local control rate of 84.7%. Local control was then reassessed as a function of substages (T1a and T1b) and dose fractionation. No difference in local control was seen in T1a and T1b neoplasms. However, after undergoing standard once-a-day fractionation, patients treated with fractions of 200 cGy had a local control rate of 96%, while those receiving 180 cGy had a local control rate of 79% (P = .05). Mean total dose for each patient group was comparable, and the median number of days of treatment interruption was the same for both groups. These data corroborate the recent findings of other authors regarding the importance of fraction size in facilitating local control of early-stage glottic cancer.

Carcinoma, Squamous Cell↗
PubMed1991

Structure and expression of the duck alpha-enolase/tau-crystallin-encoding gene.

In the duck, the glycolytic enzyme, alpha-enolase (alpha ENO) and the lens structural protein, tau-crystallin (tau CRY), are products of the same gene, an example of protein multi-functionality. We report that duck alpha ENO/tau CRY mRNA levels are developmentally regulated: alpha ENO/tau CRY mRNA levels in the lens increase over those in the liver by embryonic day 14 and, within the lens, are higher in the lens epithelium than in fiber cells. We determined the structure of the duck alpha ENO/tau CRY-encoding gene (alpha ENO/tau CRY), sequenced 1 kb of 5'-flanking region, and demonstrated that this region contains a functional promoter. The gene is 13 kb in size and is composed of twelve exons; the exon organization is identical to that of mammalian enolase-encoding genes. A fragment of 5'-flanking region (-803/+3) containing three CCAAT boxes and a TATA box was able to activate transcription of a heterologous reporter gene when transfected into cultured lens cells. However, in spite of greater quantities of alpha ENO/tau CRY mRNA and protein in the lens, the promoter was equally active in primary cultures of embryonic lens, liver and fibroblast cells. Since the cultured cells unexpectedly lost the restricted pattern of alpha ENO/tau CRY mRNA levels observed in vivo, evaluation of the promoter's tissue specificity was precluded.

Animals↗
PubMed1991

A phase I study of prolonged infusion 5-fluorouracil and concomitant radiation therapy in patients with squamous cell cancer of the head and neck.

The radiosensitization properties of 5-FU are well documented, and clinical trials have suggested improved local control and survival in head and neck cancer. Clinical trials to date have used bolus injection or short term (less than or equal to 5 days) 5-FU infusions. To determine the maximum tolerated dose (MTD) of 5-FU given as continuous intravenous infusion for 12 weeks concomitant with conventional radiation therapy, 18 patients with advanced inoperable head and neck cancers were treated with conventional irradiation and 100, 200, 250, or 300 mg/m2/day of 5-FU. A dose of 250 mg/m2/day was determined to be the maximum tolerated dose and is recommended for Phase II studies.

Adult↗
PubMed1991

Three-port perineal sparing technique.

The records were reviewed of 103 patients with low-lying pelvic malignancies irradiated with a skin-sparing technique involving use of a pair of anteroposterior-posteroanterior opposed ports and a direct perineal port. Patients had rectal, anal, cervical, vaginal, urethral, or vulvar cancer. Use of a special lead compensator allowed the three beams to be applied perpendicularly to the surface, while delivery of a homogeneous dose to the pelvis and perineum was maintained. Skin dose with this method was greatly reduced compared with that delivered with simple opposing or four-port techniques, in which irradiation is tangential to the surface at the perineum. Acute perineal skin irritation was assigned a grade between 0 and 3, with grade 0 representing the least amount of irritation. All patients were in the grade 0 or grade 1 category. Patients treated for low-lying rectal carcinoma showed no increase in perineal recurrences when compared with historic control subjects. Use of this approach allowed delivery of adequate doses to the pelvis and perineum and a definite decrease in local toxic effects, and local control was not compromised.

Adenocarcinoma↗
PubMed1991

Independent segregation of fundus albipunctatus and the transthyretin (prealbumin) gene.

A defect in the visual cycle has been suspected in patients with fundus albipunctatus (FALB), rendering genes encoding visual cycle components etiologic candidates. One such component is the retinoid and thyroxine transport protein transthyretin (TTR, prealbumin) which in the eye is synthesized only in the retinal pigment epithelium and is believed to play a role in retinal retinoid transport. The authors established polymerase chain reaction conditions that allow rapid assay of TTR alleles as defined by MspI and Fnu4HI restriction fragment length polymorphisms. In a candidate gene analysis of an affected family, they demonstrate independent segregation of the TTR and FALB disease loci. These results exclude the possibility that a TTR gene defect causes FALB in this family.

Alleles↗
PubMed1990

Radiotherapy as an adjunct in the management of Merkel cell carcinoma.

Four patients with a diagnosis of Merkel cell carcinoma initially underwent surgery followed by radiotherapy. Recurrent disease prompted use of radiation in three cases. The three cases of recurrent disease illustrate the aggressiveness of Merkel cell carcinoma and also provide further documentation of the radiosensitivity of this tumor. Additionally, these cases suggest that surgery alone frequently is inadequate to achieve local control of disease.

Aged↗
PubMed1990

Extradural spinal cord compression: analysis of factors determining functional prognosis--prospective study.

The treatment results in 59 patients with extradural spinal cord compression (ESCC) who were treated with irradiation between April 1987 and December 1988 were analyzed prospectively. Eighty percent of the patients presented with back pain, which preceded ESCC by an average of 6 weeks. The most common primary tumor was lung cancer (27% of cases), followed by prostate cancer and breast cancer. The prognostic significance of pretreatment motor function, degree of spinal cord block, radiosensitivity of tumor, and radiation dose schedule was determined with multivariate analysis. Only pretreatment motor function was found to be a significant factor in determining functional prognosis (P = .0058). Even with the increasing clinical awareness of ESCC, 78% of the patients in the current series were nonambulatory at presentation. Therefore, computed tomographic myelography or magnetic resonance imaging is recommended for patients with back pain and bone destruction at the site of the complaint if local radiation treatment is not planned.

Adolescent↗
PubMed1990

Retinoids and butyrate modulate fibroblast growth and contraction of collagen matrices.

Wound healing in the eye may lead to undesirable sequelae such as proliferative vitreoretinopathy and scarring of glaucoma filtering fistulas. We therefore sought to manipulate in vitro two key wound healing processes--cell proliferation and contraction of extracellular matrices--using vitamin A (VA), retinoic acid (RA), and n-butyrate (BUT). These substances modulate growth and differentiation of normal and neoplastic cells. We examined the effects of these agents on cultured rabbit fibroblast proliferation and contraction of collagen matrices. Dermal fibroblast proliferation was unaffected by VA, stimulated by RA, and inhibited by BUT. Scleral fibroblast proliferation, in contrast, was stimulated by both VA and RA. All three agents mildly inhibited fibroblast contraction of collagen matrices. We conclude that 1) VA, RA, and BUT have differential effects on rabbit fibroblast proliferation; 2) retinoid effects on fibroblast growth vary with the tissue of origin; and 3) VA, RA, and BUT modestly inhibit fibroblast contraction of extracellular matrices. This study suggests that fibroblast-mediated processes in ocular wound healing and cicatricial disease may be differentially modulated by retinoids and BUT.

Analysis of Variance↗
PubMed1989

Superior segmental optic hypoplasia. A sign of maternal diabetes.

In a review of 10 patients with superior segmental optic nerve hypoplasia, all of whom were the children of diabetic mothers, 17 of 20 eyes had one or more of four characteristic findings in the optic disc: relative superior entrance of the central retinal artery, pallor of the superior disc, superior peripapillary halo, and thinning of the superior peripapillary nerve fiber layer. We believe that the presence of these four signs of superior segmental optic nerve hypoplasia strongly suggests maternal diabetes.

Adult↗
PubMed1989

Intraperitoneal chromic phosphate in ovarian cancer: risks and benefits.

Between March 1977 and December 1985, 59 patients were treated with intraperitoneal chromic phosphate at The University of Alabama Birmingham Hospitals and its affiliates. Twenty-seven patients received primary adjuvant therapy. Thirty-two patients were treated "secondarily" after tumor recurrence or after a "positive" second-look laparotomy. Associated morbidity was noted to be 12% with reoperation required in 7%. Early stage and grade tumors demonstrate a good prognosis. Little, if any, benefit was demonstrated in "secondary" therapy of advanced stage and grade tumors.

Chromium↗
PubMed1989

Radiation alone in the treatment of cancer of the uterine cervix: analysis of pelvic failure and dose response relationship.

This retrospective analysis involves 569 patients with invasive cancer of the uterine cervix treated with irradiation alone between 1969 and 1980. Treatment consisted of external and intracavitary irradiation and treatment policy remained consistent throughout the study interval. In early stage disease (FIGO IA, IB, and IIA), pelvic failure was 4.6%, 11.2%, and 8.2%, respectively. In late stage disease (FIGO IIB, III, and IVA), pelvic failure was 30.1%, 52.3%, and 69.2%, respectively. Further analysis revealed that total dose at point A is well correlated with pelvic control. An aggressive treatment is crucial in late stage disease in determining the probability of pelvic tumor control and survival. Methods of dose prescription, dose-response relationships, treatment philosophy and its therapeutic implications are discussed.

Adenocarcinoma↗
PubMed1988

Analysis of treatment modalities and their failures in stage IB cancer of the cervix.

This is a retrospective analysis of 240 patients who had clinical Stage IB cancer of the cervix treated with radiation between 1969 and 1980. Of these, 186 patients were treated with a combination of external and intracavitary radiation therapy, and 54 patients received adjuvant postoperative radiation therapy. The minimum follow-up was 5 years. In the group who received only radiation therapy, the overall recurrence in 170 patients (excluding 16 patients found at laparotomy to have unresectable disease) was 17% (29 of 170); pelvic recurrence was 9% and distant metastases alone was 6%. In the group who received the adjuvant postoperative radiation therapy, 16 patients had a simple hysterectomy followed by vaginal ovoid and/or external pelvic irradiation for an unexpected Stage IB cancer of the cervix. Their overall recurrence was 37.5% (6 of 16). Pelvic recurrence was the most common treatment failure with a recurrence of 31%. Significant prognostic factors were depth of stromal invasion and status of surgical margins. Thirty-eight patients had a radical hysterectomy followed by postoperative radiation therapy because of positive pelvic lymph nodes and/or close surgical margins. In patients with positive pelvic lymph nodes, the overall recurrence was 39% (9 of 23); pelvic recurrence was 13%. Distant metastases, the most common treatment failure, was 26%. In seven patients with close surgical margins, five recurred in the pelvis. There was no distant metastases without pelvic failure. Five of eight patients with close paracervical margins recurred in the pelvis. All five of these patients were treated with vaginal ovoid irradiation alone. Whole pelvic irradiation plus vaginal ovoid irradiation is necessary in those with close paracervical margins. The vaginal ovoid irradiation alone should be limited to very selected patients with positive vaginal margins only.

Adenocarcinoma↗