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K H Luk

Publications and source records attributed to K H Luk.

At least 37 records · Page 2Linked to original sources
PubMed1984

Down-regulation of the low-density lipoprotein receptor by dietary cholesterol.

To determine the effect of dietary cholesterol on the low-density lipoprotein (LDL) receptor of circulating mononuclear cells, nine adults (six men, three women) consumed a natural diet consisting of 45% of the calories as carbohydrate, 40% as fat, and 15% as protein, polyunsaturated/saturated fatty acid ratio 0.80 to 0.84, and either 137 +/- 25 mg cholesterol per day (low cholesterol phase) or 1034 +/- 25 mg cholesterol per day (high cholesterol phase). The study lasted 2 months with 1 month in each phase and used a cross-over design. The levels of plasma triglyceride, plasma cholesterol, very low-density and high-density lipoprotein cholesterol, and apolipoproteins B, A-I, and A-II were similar in the two diet phases. The high cholesterol diet was associated with an 11 +/- 9% increase (p less than 0.02) in LDL cholesterol level and a 41 +/- 14% decrease in LDL receptor activity (p less than 0.05, n = 6). The percentage decrease in LDL receptor activity correlated with the percentage increase in LDL cholesterol (r = -0.796, p = 0.06, n = 6). Thus, high levels of dietary cholesterol can down-regulate the LDL receptor in humans.

Adult↗
PubMed1983

Adenocarcinoma of the cecum: natural history and clinical patterns of recurrence following radical surgery.

One hundred and forty-three patients with previously untreated primary adenocarcinomas of the cecum were analyzed. Fifty-three patients manifesting disseminated disease at diagnosis were analyzed to define mechanisms of disease spread. Ninety patients were analyzed following attempted curative resection to determine anatomical distribution of initial clinical recurrences. Twenty-eight patients recurred (31%), of whom 9 underwent a second laparotomy. Nineteen of the 28 patients who recurred (68%) demonstrated an initial pattern of relapse clinically confined to the abdomen, liver, and retroperitoneum. Analysis was performed to determine the influence of stage and grade of the primary tumor on prognosis. Implications for adjuvant therapy are discussed.

Adenocarcinoma↗
PubMed1983

Adenocarcinoma of the retroperitoneal ascending and descending colon: sites of initial dissemination and clinical patterns of recurrence following surgery alone.

One hundred twenty-seven patients with previously untreated primary carcinomas of proximal, retroperitoneal large bowel were retrospectively analyzed. Sites of involvement in 33 patients with surgically incurable (disseminated) disease were analyzed to define patterns of initial spread. Ninety-four patients were analyzed following attempted curative resection to determine anatomical distribution of initial clinical recurrences. Thirty-one patients recurred (33%). Twenty-four of these patients (77.5%) demonstrated an initial pattern of relapse clinically confined to the abdomen and retroperitoneum. Analysis was performed to identify factors of prognostic significance. Implications for adjuvant therapy are discussed.

Adenocarcinoma↗
PubMed1983

Radiation therapy and hyperthermia in the treatment of superficial lesions: preliminary analysis: treatment efficacy, and reaction of skin, tissues subcutaneous.

Superficial and measurable tumors were treated with hyperthermia and radiation therapy according to RTOG protocol 78-06. This study focuses on a subset of patients who were heated with microwaves. Eighty patients representing 88 lesions were treated between 1978 and 1981 with a schedule which allowed 48-96 hours to elapse between treatment sessions. The mean value of the average temperatures for individual lesions was 42.3 degrees C. The mean total radiation dose was 33.95 Gy. Skin reaction was examined in terms of the maximum score reported, using a modified Fowler scale. Erythema, the most common finding, was reported as the maximum skin reaction in 24% of the cases. Ulcerations and blisters occurred with frequencies of 18% and 7%, respectively. No reaction or desquamation was reported in 19% and 17% of the cases. Complete regression was noted in 48% of the treated lesions, partial regression in 17%, and no change in 24%. Twenty-five percent of the patients enjoyed sustained response for greater than 180 days. Refinement of hyperthermia treatment equipment and technique may result in less normal tissue reaction and improved clinical responses. In view of the encouraging initial results, we recommend aggressive pursuit of hyperthermia as a new treatment modality.

Adenocarcinoma↗
PubMed1982

CT and radiation therapy planning: impact of LOCATE ScoutView images.

LOCATE, a new computer software program, was used to outline tumor margins on scanned projection radiographs (ScoutView). This information was transferred to simulator radiographs and the results compared with tumor margins determined by all other methods. Twenty-two patients with various types of tumors in different parts of the body were studied with computed tomography and then therapy planned without the benefit of images from this program. When program information was made available, it stimulated a change in the radiation therapy plan in 18 cases (82%). Phantom studies demonstrated that magnification inherent in the program images was not significantly different from that in simulator radiographs. Program-generated tumor margins on ScoutView images were shown to accurately reflect tumor margins outlined on cross-sectional computed tomographic images as long as no patient motion occurred on the table during the study. LOCATE provides a useful means of tumor localization for therapy planning in many cases.

Humans↗
PubMed1981

Carcinoma of penis. Review of cases treated by surgery and radiation therapy 1960-1977.

Cases of squamous cell carcinoma of the penis treated by surgery and radiation therapy at Moffitt Hospital, University of California, and Mount Zion Hospital and Medical Center are reviewed. Only cases followed for more than three years or with autopsy findings are presented. For the primary lesion, over-all surgical control rate locally was 15/17 or 88 per cent. Over-all control rate with radiation therapy alone was 9/12 (75 per cent), and with surgical salvage 11/12 (92 per cent). Radiation therapy appears to be the treatment of choice for early stage lesions, reserving surgery for salvage. Prophylactic ilioinguinal lymph node dissection for N0 lesions is not warranted. The role of chemotherapy needs further investigation.

Carcinoma, Squamous Cell↗
PubMed1980

Hyperthermia in cancer therapy.

Many malignant cell lines exhibit a therapeutic response to supernormal temperatures. Selective destruction of tumor cells has been observed following moderate hyperthermia (42 degrees to 43 degrees C) in vivo, and tumor eradication by heat has been achieved without normal tissue morbidity. Thermal cell killing appears to be independent of oxygen tension, and the sensitivity of S-phase cells to thermal damage is complementary to that for cellular radiation response. Hyperthermia is therefore a promising adjunct to radiotherapy. At the Claire Zellerbach Saroni Tumor Institute, Mount Zion Hospital and Medical Center, San Francisco, the differential thermal sensitivity of malignant cells is being studied to achieve improved tumor control in patients refractory to more conventional treatments. Preliminary results of a two-year clinical trial indicated increased local objective responses when hyperthermia and radiation were used in combination.

Diathermy↗
PubMed1979

Medulloblastoma: treatment results and effect on normal tissues.

Thirty-three children under age 20 with medulloblastoma, treated between 1962 and 1976, at the University of California and the Claire Zellerback Saroni Tumor Institute of Mount Zion Hospital, San Francisco, were retrospectively studied. A relationship between dose and local control rate was suggested by an improved five-year survival in those patients receiving doses greater than 5000 rads to the posterior fossa. The posterior fossa, either alone or with the spinal cord, was the most frequent site of failure. Results of re-irradiation for failure were encouraging and no significant complications were noted. A study of the effects of craniospinal irradiation on the hematopoietic and immune system demonstrated a marked decrease in the peripheral lymphocyte population at the completion of therapy and suggested a functional impairment of the remaining lymphocytes. Other side effects of irradiation included suppression of the hypothalamic-pituitary axis and one instance of brain necrosis. Current treatment policy and proposals for future modifications are discussed.

Adolescent↗
PubMed1979

The use of 2450 megahertz of microwave in cancer therapy; a pilot study.

Contraindications to microwave diathermy traditionally include malignant tumors. This paper describes a pilot study of tissue hyperthermia treatment (average 42.5 degrees C, 108.5 degrees F) for superficial cancers, using 2450 megahertz of microwave diathermy. Tissue temperatures were recorded for prolonged periods of time, and tumor responses to heat alone, or to heat combined with radiation therapy, were observed. Such treatments were tolerated by the patients, but were not without side effects. Preliminary results of this pilot study, as well as those of other investigators, showed that tissue hyperthermia would be a useful treatment modality for cancer therapy. The familiarity of physical therapists with microwave diathermy may be an asset to them as clinicians. Physical therapists, however, should not attempt to treat cancer patients alone. Further clinical research in the area should be conducted in the proper setting under the guidance of an oncologist.

Body Temperature↗
PubMed1979

Thermal dosimetry and clinical requirements.

Major problems in clinical hyperthermia include (a) inhomogeneity of heat distribution in designated tumor volumes due to tissue characteristics and differential blood flow, (b) limitations of heat delivery and control systems for adequate depth penetration and adjustments of temperatures, and (c) the lack of capability of accurate temperature measurements, especially in the area of noninvasive techniques for deep-seated tumors. Examples were given to illustrate the clinical requirements of hyperthermia of superficial, intermediate, and deep-seated tumors.

Brain Neoplasms↗
PubMed1978

137Cs afterloading intrauterine packing for stage I and stage II adenocarcinoma of the endometrium.

Eleven patients with Stage I or Stage II adenocarcinoma of the endometrium were treated with 137Cs afterloading intrauterine packing. Treatment results and complications were similar to those obtained with radium afterloading tandems and colpostats (20 patients) and Heyman packing (2 patients). 137Cs is preferable in patients with roomy or irregular intrauterine cavities and also offers reduced radiation exposure to personnel.

Adenocarcinoma↗
PubMed1977

The role of radiation therapy in the treatment of germinal cell tumors of the testis other than pure seminoma.

Between March 1944 and September 1976, 279 patients with nonseminomatous testicular tumors were treated. The 3-year NED rates for patients with Stages I, IIA, and IIB were 78.2%, 46.7%, and 17.6%, respectively. However, the results were better for patients treated with preoperative radiotherapy and lymphadenectomy with or without postoperative radiotherapy (Stage IIA: 77.5%--14/18; Stage IIB: 12.9%--3/7). Postoperative radiotherapy is not necessary for patients with negative nodes at lymphadenectomy because the periaortic failure rate is low for this group. However, when positive nodes are found, the control is improved with radiotherapy. The minimum tumor dose required when tumor is found but resected is not known. When there is gross residual tumor, a dose of 4,500-5,500 rad is required to achieve any salvage. In this series, 42.2% of patients with positive nodes at lymphadenectomy (Stages I and II) developed extranodal metastases. This group might benefit from adjunctive chemotherapy.

Choriocarcinoma↗
PubMed1977

Desmoid tumors--treatment and prognosis.

Desmoid tumors are locally invasive benign tumors arising from musculoaponeurotic structures which are classified as fibromatoses and which have generally high post-surgical recurrence rates. Sixteen patients with desmoid tumors were treated with irradiation and evaluated for 2 to 6 years post-treatment. Of the 16, 13 cases have been controlled without recurrence. Virtually complete resolution of the tumor mass has been accomplished without the disfigurement and dysfunction characteristic of the radical surgical approach to treatment.

Adolescent↗