Biomedical subjects

K Y Look

Publications and source records attributed to K Y Look.

At least 55 records · Page 3Linked to original sources

PubMed1993

Vulvar melanoma reconsidered.

BACKGROUND: Melanoma of the vulva has traditionally been treated with radical vulvectomy and bilateral inguinofemoral lymphadenectomy. Cutaneous nonvulvar melanoma has been successfully treated with local excision with selective therapeutic regional node dissection. METHODS: A retrospective analysis of 16 patients with primary malignant melanoma of the vulva who underwent surgery from 1973 to 1988 at Indiana University Hospital was conducted. The purpose of this analysis was to determine if less radical surgery, such as that performed for cutaneous nonvulvar melanoma, might be adopted for patients with vulvar melanoma without compromising 5-year survival results. RESULTS: Surgical therapy included radical vulvectomy with bilateral inguinofemoral lymphadenectomy (n = 11), radical vulvectomy alone (n = 1), and wide local excision (n = 4). Treated International Federation of Gynecology and Obstetrics (1971) stages included I (n = 12), II (n = 3), and III (n = 1). The median age of the patients was 59 years (range, 29-79 years). The median depth of invasion according to the Breslow method was 3 mm (range, 0.1-8 mm). Patients were observed for a median of 24 months (range, 3-143 months). The Kaplan-Meier 5-year survival estimate was 30%. There were nine recurrences: five distant, one central, one nodal, and two mixed. A median depth of 0.9 mm (range, 0.1-1.75 mm) was noted in those who remained disease-free versus 4.6 mm (range, 3-8 mm) in those who experienced a recurrence (P < 0.01). None of the patients with lesion depths of 1.75 mm or smaller experienced a recurrence, whereas all of those with lesion depths larger than 1.75 mm suffered a recurrence (P = 0.0004). CONCLUSIONS: Patients with lesion depths of 1.75 mm or smaller may be treated with wide local excision. Patients with greater lesion depths are at high risk for the development of distant metastases. The patients with well-lateralized lesions may be equally well served with a less morbid procedure deferring therapeutic node dissection until there is a regional recurrence.

Adult↗

PubMed1993

Blood transfusion and the risk of recurrence in squamous carcinoma of the vulva.

OBJECTIVE: Our purpose was to determine if postoperative transfusion increases the risk of recurrence in patients who have undergone operation for squamous carcinoma of the vulva. STUDY DESIGN: Data from 154 patients with squamous carcinoma of the vulva treated at Indiana University Medical Center from 1974 through 1988 were retrospectively analyzed to determine the influence of postoperative transfusion on recurrence risk. Patients were evaluated for International Federation of Gynecology and Obstetrics stage, lesion size, lesion depth, grade, patient age, number of transfusions, and recurrence with chi 2 analysis, Fisher's exact test, and the Student t test where appropriate. RESULTS: Transfusions were given to 57 patients (37%) with a mean of 2.2 units delivered (range 1 to 5 units). Transfused patients differed significantly from those not transfused in that they had more advanced stage (p = 0.002), more positive nodes (p = 0.03), and higher grade lesions (p = 0.03), and they were older (p = 0.005). Recurrences developed in 25 patients (16.2%). Recurrences were more common in those with positive nodes (10-39, 25.6%) than in those with negative nodes (8/99, 8%), (p = 0.01). Only nodal status was predictive of recurrence in this series. Transfused patients had a 14% (8/57) rate of recurrence, whereas the recurrence risk was 17.5% (17/97) in those not transfused (p = 0.65). CONCLUSIONS: We have been unable to confirm that postoperative transfusions increase the risk of recurrence in patients with squamous carcinoma of the vulva.

Adult↗

PubMed1993

Regulation of deoxycytidine kinase activity and inhibition by DFDC.

(1) Deoxycytidine kinase activity increased in a transformation- and progression-linked fashion in rat hepatomas of different proliferation rates. The activity also increased and was growth rate-linked in a series of tissue culture cell lines of human and animal tumors. (2) Deoxycytidine kinase activity was stringently linked with expression of the neoplastic proliferative program as it sharply increased in log phase in tissue culture cells of hepatoma 3924A and several human carcinoma strains. (3) Deoxycytidine kinase is subject to nutritional and hormonal regulation. On starvation the activity in liver decreased and on refeeding it returned to normal. Steroid hormone increased liver enzymic activity. Deoxycytidine kinase is substrate-inducible, since deoxycytidine injections in rat led to a 2- to 3-fold increase in hepatic enzyme activity. (4) Actinomycin or cycloheximide treatment blocked the increase in liver deoxycytidine kinase activity induced by steroid or deoxycytidine treatment. Therefore, it is assumed that the rise in deoxycytidine kinase activity requires new RNA and protein synthesis. (5) Cycloheximide treatment of rats carrying hepatomas yielded a t1/2 = 3.4 hr in the tumor for deoxycytidine kinase activity which was the shortest among the examined enzymes of purine and pyrimidine biosynthesis. (6) Actinomycin treatment of rats carrying hepatomas yielded a t1/2 of 5.8 hr for deoxycytidine kinase activity in the tumor which was one of the shortest in the examined enzymes of purine and pyrimidine biosynthesis. (7) Difluorodeoxycytidine (DFDC) is a competitive inhibitor (Ki = 7-28 microM) of deoxycytidine kinase from rat hepatoma and from human pancreatic carcinoma and ovarian carcinoma cells in culture.

Animals↗

PubMed1993

Phase II trial of ifosfamide and mesna in patients with advanced or recurrent squamous carcinoma of the cervix who had never received chemotherapy: a Gynecologic Oncology Group study.

OBJECTIVE: Our objective was to determine the activity of ifosfamide and mesna in women with advanced or recurrent squamous carcinoma of the cervix who had never received chemotherapy. STUDY DESIGN: This is a phase II drug study in which the starting dose of ifosfamide was 1.5 gm/m2 daily intravenously for 5 days. The starting dose of ifosfamide was reduced to 1.2 gm/m2 daily in patients who had received prior radiotherapy. The uroprotector mesna was given intravenously with, and at 4 and 8 hours after, the administration of ifosfamide. Each dose of mesna was 20% of the total daily dose of ifosfamide. RESULTS: Fifty-six patients were placed in the study; 52 were evaluable for toxicity and 51 for response. Twenty-eight (54.9%) patients had previously undergone surgery and 46 (90.2%) had received radiotherapy before this trial. Gynecologic Oncology Group grade 3 or 4 granulocytopenia occurred in 7 (13.5%) patients, and 2 (3.9%) had grade 3 thrombocytopenia. Six (11.5%) patients had grade 3 or 4 neurotoxicity. Complete response was observed in 2 (3.9%) patients and partial responses in 6 (11.5%) patients, for a total response rate of 15.7% (95% confidence interval 7.02% to 28.59%). CONCLUSIONS: This response rate is higher than that reported by the Gynecologic Oncology Group in patients with previously treated squamous carcinoma of the cervix. Our findings fail to confirm that ifosfamide is a highly active agent in patients with squamous carcinoma of the cervix as reported by others; nonetheless, the observed activity of this drug deserves further study in combination therapy of squamous carcinoma of the cervix.

Adult↗

PubMed1993

A Gynecologic Oncology Group phase II study of amonafide (NSC 308847) in epithelial ovarian cancer.

In this study, 19 evaluable patients with epithelial ovarian cancer were treated with amonafide 300 mg/m2 over an hour for 5 consecutive days every 3 weeks. One partial response (5%) was seen. Hematologic toxicity was substantial with grade 3 or 4 toxicity occurring as follows: leukopenia, 10 patients (45%); thrombocytopenia, 6 patients (27%); granulocytopenia, 8 patients (36%). No other unusual or severe toxicity occurred. In view of the low response rate and high toxicity, amonafide does not warrant further investigation in epithelial ovarian cancer.

Adenine↗

PubMed1992

Inhibition by tiazofurin of inosine 5'-phosphate dehydrogenase (IMP DH) activity in extracts of ovarian carcinomas.

Cancer cells have an increased ability to synthesize GTP (guanosine triphosphate) because of increased activity of IMP DH (inosine 5'-phosphate dehydrogenase, EC 1.1.1.205). Because IMP DH activity is rate limiting for de novo biosynthesis of GTP, this enzyme was suggested as a sensitive target for chemotherapy. Tiazofurin (2-beta-D-ribofuranosylthiazole-4-carboxamide) is converted in the cells into the active metabolite, TAD, (thiazole-4-carboxamide adenine dinucleotide) which potently inhibits IMP DH activity. By adding TAD to tissue extracts one can determine the extent of inhibition of IMP DH. We applied the IMP DH assay method to extracts of normal ovaries (N = 11) and epithelial ovarian carcinomas (N = 10). The IMP DH activity (mean +/- SE) in ovarian carcinoma was 21.1 +/- 5.8 which was markedly higher than that observed in normal ovaries (2.9 +/- 0.7 nmol/hr/mg protein) (P < 0.05%). The inhibition by TAD of IMP DH activity in ovarian carcinomas (N = 4) was 81%. The results indicate that IMP DH activity is elevated sevenfold in ovarian carcinomas as compared to normal ovary and can be inhibited by exposure to tiazofurin (TAD). Similar high IMP DH activity and inhibition of the activity by TAD was observed in patients with chronic granulocytic leukemia in blast crisis among whom 70 to 80% remissions were reported. Since there is increased IMP DH activity in human ovarian carcinomas and in OVCAR-5 cells and tiazofurin and TAD inhibit IMP DH activity of these cells and the proliferation of human ovarian carcinoma xenografts in the mouse, tiazofurin may merit serious consideration for a Phase II trial for patients with recurrent/refractory epithelial ovarian carcinoma.

Adenocarcinoma↗

PubMed1992

Recurrent squamous carcinoma of the vulva.

OBJECTIVE: This study reviews experience at Indiana University with recurrent squamous carcinoma of the vulva over an 18-year period from 1971 to 1989. The pattern of recurrence, time interval to recurrence, and efficacy of salvage therapy are evaluated in the context of the primary tumor. STUDY DESIGN: This is a retrospective study of 40 patients, 21 of whom underwent primary therapy for invasive squamous carcinoma of the vulva at Indiana University. RESULTS: Vulvar recurrences were observed in 17 patients (43%), the groin was involved in 12 (30%), whereas pelvic and distant recurrences were observed in 2 (5%) and 9 (22.5%) patients, respectively. Salvage surgery and/or radiotherapy were successful in 25 patients (62.5%) alive from 1 to 144 months (median 8 months) from secondary therapy. Survival after retreatment varied significantly by site of recurrence (p = 0.002), tumor grade (p = 0.009), and interval to recurrence (p < 0.001). Best outcomes were in patients with initial stage I or II disease (International Federation of Gynecology and Obstetrics), grade 1 tumors, local failure, and interval to relapse of > 16 months' duration. Two of 12 patients with groin recurrences were salvaged with surgery and radiotherapy. CONCLUSION: Long-term follow-up of patients with vulvar cancer and careful restaging at the time of recurrence are mandatory. Although local and nodal recurrences may be controlled with surgery and/or radiotherapy, regional recurrences are usually fatal.

Adult↗

PubMed1992

5-fluorouracil and low-dose leucovorin in the treatment of recurrent epithelial ovarian carcinoma. A phase II trial of the Gynecologic Oncology Group.

Twenty-one patients with recurrent epithelial ovarian carcinoma not amenable to cure with further surgery or radiotherapy were entered into a Phase II trial utilizing i.v. leucovorin at 20 mg/m2 followed by i.v. 5-fluorouracil at 425 mg/m2 administered daily for 5 days every 4 weeks for the first two courses and then every 5 weeks. Twenty-one patients were entered. Of these, 20 were eligible for toxicity assessment and 19 for response. Five had received prior radiotherapy, and all had received prior cisplatin-based chemotherapy. There was one patient response (5.3%; 95% confidence intervals for response of 0% to 26%). Toxicity was moderate with 5 of 20 (25%) grade 3 or 4 leukopenia, 12 of 20 (60%) grade 3 or 4 granulocytopenia, 1 of 20 (5%) grade 3 thrombocytopenia, 5 of 20 (25%) grade 3 GI toxicity, and 2 of 20 (10%) grade 3 neurotoxicity. There was one toxic death in a patient who developed granulocytopenia and pneumonia after her third course of treatment. This dose schedule of 5-fluorouracil and leucovorin has minimal activity in patients with recurrent epithelial ovarian carcinoma who have received prior cisplatin chemotherapy.

Adult↗

PubMed1992

5-fluorouracil and low-dose leucovorin in the treatment of recurrent squamous cell carcinoma of the cervix. A phase II trial of the Gynecologic Oncology Group.

Twenty-eight patients with recurrent squamous carcinoma of the cervix not amenable to cure by further surgery or radiation therapy were entered into a Phase II trial utilizing i.v. leucovorin 20 mg/m2 followed by 5-fluorouracil 425 mg/m2 administered daily for 5 days every 4 weeks for the first two courses and then every 5 weeks. One patient never received therapy, and three are inevaluable for response; therefore, 27 patients were evaluable for toxicity and 24 for response. Twenty-three patients had received prior radiotherapy, and 16 had received prior chemotherapy. There was one partial response 4.2% (95% confidence intervals for a response of 0 to 21%). Although toxicity was acceptable with 11 of 27 (41%) grade 3 or 4 leukopenia, 1 of 27 (4%) grade 3 thrombocytopenia, and 3 of 27 (11%) grade 3 or 4 gastrointestinal toxicity, this dose schedule of 5-fluorouracil and leucovorin has minimal activity in recurrent squamous carcinoma of the cervix.

Adult↗

PubMed1992

Immunohistochemical study of HER-2/neu, epidermal growth factor receptor, and steroid receptor expression in normal and malignant endometrium.

HER-2/neu oncogene protein, epidermal growth factor receptor, progesterone receptor, and estrogen receptor were examined immunohistochemically in specimens of normal and neoplastic endometrium. Tissues obtained at the time of hysterectomy were snap-frozen at liquid nitrogen temperature and serially sectioned at 4 microns. Normal endometrial epithelial cells stained with anti-epidermal growth factor receptor and anti-HER-2/neu with intensities graded from 0 to 3+. Of the 49 endometrial malignancies studied, seven (14%) contained tissue exhibiting HER-2/neu staining in excess (4+) of any of the normal tissues or the other 42 cancer specimens. Expression of both HER-2/neu and steroid receptors was heterogeneous within these seven tumors. To examine this heterogeneity more closely, sections of these and other tumors were double-stained for HER-2/neu and progesterone receptor. It was found that the cells exhibiting 4+ HER-2/neu staining were progesterone receptor-negative. Conversely, cells that were progesterone receptor-positive within the same specimen exhibited HER-2/neu immunostaining equal to or less than 3+. All specimens containing 4+ HER-2/neu tissue were graded 1 or 2 adenocarcinomas, stage I. Thus, there is an inverse relationship between overexpression of HER-2/neu and progesterone receptor in endometrial cancer. On the other hand, overexpression of HER-2/neu in endometrial cancer does not seem to be related to loss of other differentiated characteristics. The prognostic value of these observations awaits continued study.

Biomarkers, Tumor↗

PubMed1991

Trends in the operative management of invasive squamous carcinoma of the vulva at Indiana University, 1974 to 1988.

From January 1974 to March 1988, 150 patients with primary invasive squamous cell carcinoma of the vulva underwent surgery at Indiana University. There has been a trend toward more conservative surgical management of this disease. To determine the impact of this trend on clinical outcome, cases were divided into three groups according to date of operation: group I, 1974 to 1978; group II, 1979 to 1983; and group III, 1984 to 1988. Overall, 80 patients had en bloc radical vulvectomy and groin dissection, 20 had modified radical vulvectomy and bilateral groin dissection through three separate incisions, and 36 had modified radical vulvectomy and unilateral superficial groin dissection. Fourteen patients had other operations. Forty-two patients (27.3%) had radiotherapy in addition to surgery. Among the three groups, there were no differences when mean age, International Federation of Gynecology and Obstetrics stage distribution (1988 system), mean lesion size, mean depth of invasion, or grade distribution were compared. A significant trend toward more conservative surgical therapy was observed. En bloc radical vulvectomy was performed in 77.4% of group I patients, 71.1% of group II patients, and 35.8% of group III patients (p less than 0.001). Mean days of hospitalization were also reduced significantly. Group I had a mean stay of 30 days, group II had a mean stay of 23 days, and group III had a mean stay of 11 days (p less than 0.001). Mean operative blood loss (group I, 754.8 ml; group II, 620.0 ml; group III, 393.6 ml; p = 0.03), mean units of blood transfused (group I, 1.4 units; group II, 1.3 units; group III, 0.4 units; p less than 0.01), and mean hours of operating time (group I, 3.7 hours; group II, 3.7 hours; group III, 3.2 hours; p = 0.02) were also reduced.

Adult↗

PubMed1991

Analysis of invasive squamous cell carcinoma of the vulva and vulvar intraepithelial neoplasia for the presence of human papillomavirus DNA.

We have analyzed a number of invasive squamous cell carcinomas for the presence of human papillomavirus (HPV) DNA using dot blot and Southern blot analysis. Seven of 31 samples (23%) were positive by dot blot and/or Southern blot analysis. In contrast, six of 11 (55%) of vulvar intraepithelial neoplasias contained HPV DNA by dot blot and/or Southern blot hybridization. Less than 50% of the invasive vulvar carcinomas contained detectable HPV DNA. The average age at onset of vulvar carcinoma is higher than that for cervical carcinoma (in which HPV DNA is detected in over 80% of cases). Therefore, the role of HPV in the genesis of vulvar carcinoma may be different from the role of HPV in the genesis of cervical carcinoma.

Adult↗

PubMed1990

Relapse patterns in FIGO stage IB carcinoma of the cervix.

Site of recurrence and survival data were reviewed for 96 patients with FIGO stage IB cervical carcinoma treated between July 1978 and December 1986 with radical surgery (N = 55), radiation therapy (N = 30), or combination therapy (N = 11). There were 21 patients (21.8%) who suffered recurrences. After radiation 10 of 30 (33.3%) patients recurred versus 11 of 55 (20%) after radical surgery alone. Recurrences were observed in 6 of 14 (42.8%) patients with positive nodes, 11 of 61 (18%) patients with negative nodes, and 4 of 21 (19%) patients with unknown nodal status. The first manifestation of recurrence was central in 3, locoregional in 9, and distant in 9. The median disease-free interval (DFI) was 11 months for surgical and 10.5 months for irradiated patients. The 2-year disease-free survival was 83.6% for surgical patients and 73.3% for irradiated patients. The risk of distant metastases was 3 of 55 (5.4%) following radical surgery and 6 of 30 (20%) after radiation (P = 0.04). The median time to pelvic recurrence was 10 months and that for distant recurrence was 20 months (P less than 0.05). The median time to pelvic relapse was 9.5 months for radical surgery patients and 10 months for irradiated patients. The median time to distant recurrence was 20 months for radical surgery patients and 16.5 months for irradiated patients. Median survival in those who died of disease after a recurrence confined to the pelvis was 15 months versus 8 months for those with a distant recurrence (P less than 0.05). Our data confirm that (1) site of relapse is influenced by primary therapeutic modality and (2) pelvic recurrence manifests before distant recurrence; however, median DFI for all recurrences as well as for the subsets of pelvic and distant relapses is independent of primary modality. We suggest that an understanding of the natural history of cervical cancer recurrence will allow optimal use of resources in the follow-up of patients to detect recurrence.

Adenocarcinoma↗

PubMedDate not supplied

Evolution of screening for epithelial ovarian carcinoma: the quest for early diagnosis.

Epithelial ovarian carcinoma remains the most fatal of gynecologic malignancies, causing approximately 13,300 deaths annually. This high mortality rate is due to the presence of advanced stage disease at time of diagnosis. Symptoms early in the course of the disease are frequently nonspecific and go unrecognized by both the patient and the physician. The cause-specific mortality may decrease if a sufficiently sensitive screening modality can be developed to allow early diagnosis and curative therapy. The ideal screening tests or algorithm utilizing several tests must have sufficient specificity to minimize false positives, which contribute to patient anxiety and inefficient use of health care dollars. The development and refinement of the various methodologies used in screening of epithelial ovarian carcinoma will be the subject of this review.

Adult↗

PubMedDate not supplied

Coexistence of metastatic neuroendocrine carcinoma of the uterine cervix with human immunodeficiency virus infection.

Women now constitute 28% of new cases of human immunodeficiency virus (HIV) infection. Cervical cancer in HIV-infected women has a high recurrence and death rate, as well as decreased intervals to recurrence and death. Neuroendocrine carcinomas of the cervix are characterized by a high frequency of early nodal and distant metastases. We present the first report of a neuroendocrine carcinoma of the cervix in an HIV-positive patient. A 28 year old with a 9-year history of HIV succumbed to metastatic neuroendocrine carcinoma of the cervix 5 months after diagnosis. Given the aggressive nature of the cell type, an extended metastatic workup should be considered prior to surgery. The immune suppression present in HIV-positive patients with neuroendocrine cervical carcinoma may make such a workup particularly crucial, such that surgery is offered only to those who can be expected to benefit.

Adult↗

PubMedDate not supplied

The risk of nodal metastasis in early adenocarcinoma of the uterine cervix.

A functional and widely accepted definition of microinvasive cervical adenocarcinoma remains elusive. The purpose of this study was to determine at which depth of invasion the likelihood of lymph node metastasis or disease recurrence was so small that conservative surgery could be considered appropriate. Charts of patients with adenocarcinoma of the cervix (ACC) who underwent radical hysterectomy and pelvic lymphadenectomy (n = 98) at Indiana University Medical Center from 1987 to 1998 were retrospectively reviewed. Patients with stage IA1-IB1 lesions were included in the study. Patients treated with preoperative radiotherapy were excluded. Pathologic parameters evaluated included histologic type, depth of stromal invasion (DOI), and the presence of lymphatic vascular space invasion, or lymph node metastases. The patient median age was 39 years (20-65). The median time of follow-up was 30 months (4-124). Lymph node metastases were found in ten patients and 11 developed recurrences. The precise DOI could be measured in 84 patients. Of the 48 patients with cancers with a DOI </= 5 mm, none had involved parametria or nodes; whereas eight of the 36 with a DOI > 5 mm had nodal metastases (P = 0.00069). None of these 48 patients with a tumor DOI </= 5 mm developed a recurrence whereas six of the 36 patients with a tumor DOI > 5 mm developed recurrent disease (P = 0.0048). The risk of nodal metastases and recurrence is so low in patients with ACC and DOI </= 5 mm that for patients with such depth documented on conization with negative margins pelvic lymphadenectomy may be omitted.

Adenocarcinoma↗

PubMedDate not supplied

The utility of presurgical CA125 to predict optimal tumor cytoreduction of epithelial ovarian cancer.

The objective of this study was to evaluate the ability of a preoperative serum CA125 to predict whether optimal debulking (OD) could be achieved for patients with stage III and IV epithelial ovarian cancer (EOC). The records of consecutive patients who underwent primary surgery for EOC at Indiana University Hospital between January 1997 and January 2003 were reviewed. Eligibility criteria included FIGO stage III/IV disease, surgery by gynecologic oncology faculty, preoperative CA125, and an operative note clearly defining volume of residual disease. The Medcalc software statistical package was used to generate a receiver-operating characteristic (ROC) curve. Two hundred and eighty-nine cases of stage III/IV EOC were identified, of which 164 met the eligibility criteria. Serum CA125 </=400 was associated with OD >/=75% of the time. Conversely, OD was achieved in </=40% of patients with CA125 >/=4500. The area under the ROC curve for CA125 was .670. The OD rate for those with and without ascites was 49% and 79%, respectively (P < 0.001). In a multivariate analysis using CA125, age, and ascites, the area under the curve was 0.686. We conclude that preoperative serum CA125 did not reliably predict OD in patients with stage III-IV EOC.

Adenocarcinoma↗

PubMedDate not supplied

Differences in thermostability of thymidine kinase isoenzymes in normal ovary and ovarian carcinoma.

UNLABELLED: Thymidine kinase 1 (TK 1 EC. 2.7.1.21) the most specific and cell-cycle regulated salvage enzyme for pyrimidine nucleoside supply of DNA synthesis is a promising target to rationally designed chemo- and other therapies. The present study was undertaken to compare the heat stability of TK isoenzymes of both normal ovarian and epithelial ovarian cancer cells. Tissue extracts of epithelial ovarian carcinomas (N = 7) and normal ovaries (N = 9) were analyzed for thymidine kinase activity using the polyethyleneimine-cellulose disc radioassay. The TK activity in extracts of ovarian carcinomas was 12-fold higher than in extracts of normal ovaries. The TK activity of ovarian carcinomas decreased significantly even after 30 minutes incubation at 37 degrees C while, the enzyme activity of normal ovarian extracts was more stable and decreased to the same extent after 120 minutes. The half-life time of the enzyme activity was 82 min in the normal but only 36 minutes in the cancer tissue extract at 37 degrees C. CONCLUSION: The TK activity of malignant ovarian cells was much higher but more unstable (t1/2 = 36 minutes) than the enzyme isolated from healthy ovaries (t1/2 = 82 minutes). This profound difference in thermostability might provide the molecular background for hyperthermia combined with chemotherapy as a promising treatment for ovarian malignancies.

Adult↗