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H J Schmoll

Publications and source records attributed to H J Schmoll.

At least 19 recordsLinked to original sources
PubMed2006

Comparison of an aprepitant regimen with a multiple-day ondansetron regimen, both with dexamethasone, for antiemetic efficacy in high-dose cisplatin treatment.

BACKGROUND: We compared an aprepitant regimen with a control regimen of ondansetron + dexamethasone given for 4 days. PATIENTS AND METHODS: Patients scheduled to receive cisplatin > or =70 mg/m(2) were randomized to either the aprepitant regimen (aprepitant, ondansetron and dexamethasone on day 1; aprepitant and dexamethasone on days 2-3; dexamethasone on day 4) or control regimen (ondansetron + dexamethasone on days 1-4). Patients recorded vomiting, nausea and rescue therapy use. The primary end point was complete response (no vomiting and no use of rescue therapy) in the overall phase (days 1-5 post-cisplatin). RESULTS: Complete response rates were higher in the aprepitant than control group in the overall (72% versus 61%; P = 0.003), acute (day 1; 88% versus 79%; P = 0.005) and delayed phases (days 2-5; 74% versus 63%; P = 0.004), as were rates of no vomiting (overall 77% versus 62%, P < or = 0.001; acute 89% versus 81%, P = 0.004; delayed 79% versus 64%, P < or = 0.001). Rates of no rescue therapy were similar between groups. CONCLUSIONS: Compared with an antiemetic regimen in which ondansetron + dexamethasone were given for 4 days, the aprepitant regimen was superior in the acute, delayed and overall phases of chemotherapy-induced nausea and vomiting. The aprepitant regimen should be considered a new standard of antiemetic therapy for cisplatin-treated patients. www.ClinicalTrials.gov Identifier: NTC00090207.

Adult↗
PubMed2005

Potential activity of paclitaxel, vinorelbine and gemcitabine in anaplastic thyroid carcinoma.

Anaplastic thyroid carcinoma (ATC) has a rapidly fatal course in the mostly elderly patients with a median survival after diagnosis of 4-12 months. Activity of commonly used chemotherapy (doxorubicin) is low, thus more active compounds need to be introduced into the therapeutic concept of ATC. Recently, based on preclinical data Ain et al. conducted a clinical phase II study with paclitaxel 96 h infusion in ATC achieving a promising response rate of 53%. To further improve therapeutic options in ATC, we evaluated the activity of topotecan, oxaliplatin, vinorelbine, gemcitabine and paclitaxel in comparision to cisplatin and doxorubicin (1 and 96 h drug exposure) alone or in combination in the ATC cell lines SW1736 and 8505C. IC50 values were determined by the sulforhodamine B assay, potential clinical activity was estimated by relative antitumor activity (RAA) and drug interaction was analyzed using a parametric response surface approach (Greco model) of the Loewe additivity. Duration of drug effect was estimated by regrowth kinetics. We found paclitaxel, vinorelbine and gemcitabine active in ATC with RAA (1 h drug exposure) ranging from 86 to 454, 15 to 17 and 31 to 140, respectively. The activity of doxorubicin and cisplatin was moderate with RAA ranging from 1.4 to 2.2 and 0.2 to 0.3, respectively. Combined drug exposure of gemcitabine/paclitaxel and gemcitabine/vinorelbine was synergistic with a Loewe index > 0. However, these results did not reach statistical significance with p > 0.05. At clinically relevant drug concentrations paclitaxel, gemcitabine and vinorelbine but not oxaliplatin exerted a sustained growth inhibition after cessation of drug exposure for the complete assay time of 15 days. In conclusion, paclitaxel, gemcitabine and vinorelbine but not topotecan or oxaliplatin appeared to be active in anaplastic thyroid carcinoma based on RAA or growth delay at clinically relevant drug concentrations. Combinations of vinorelbine/gemcitabine and paclitaxel/gemcitabine exerted a trend to synergy. Thus, further evaluation of paclitaxel, vinorelbine and gemcitabine alone or in combination with ATC seems warranted.

Antineoplastic Agents↗
PubMed2004

Intensive chemotherapy with idarubicin, cytarabine, etoposide, and G-CSF priming in patients with advanced myelodysplastic syndrome and high-risk acute myeloid leukemia.

In an attempt to improve the complete remission (CR) rates and to prolong the remission duration especially in elderly patients > 50 years of age, we have used a combination chemotherapy of idarubicin (10 mg/m2 IV x 3 days), cytarabine (AraC, 100 mg/m2 CIVI x 7d), and etoposide (100 mg/m2 x 5 days) in combination with granulocyte colony-stimulating factor (G-CSF) priming [5 mg/kg SQ day 1 until absolute neutrophil count (ANC) recovery] for remission induction. Responding patients received two consolidation courses of idarubicin, AraC, and etoposide, followed by a late consolidation course of intermediate-dose AraC (600 mg/m2 IV every 12 h x 5 days) and amsacrine (60 mg/m2 IV x 5 days). A total of 112 patients (57 male/55 female) with a median age of 58 years (range: 22-75) have been entered and are evaluable for response: 19 refractory anemia with excess of blast cells in transformation (RAEB-T), 84 acute myeloid leukemia (AML) evolving from myelodysplastic syndrome (MDS), and 9 secondary AML after chemotherapy/radiotherapy. The overall CR rate was 62%, partial remission (PR) rate 10%, treatment failure 16%, and early death rate 12%. The CR rate was higher in patients < or = 60 years (68 vs 55%), mainly due to a lower early death rate (5 vs 21%, p<0.001). After a median follow-up of 58 months, the median overall survival is 14.5% and median duration of relapse-free survival 8 months. After 60 months, the probability of CR patients to still be in CR and alive is 16% (20% in patients < or = 60 years and 13% in patients >60 years), while the probability of overall survival is 12% (15% in patients < or = 60 years and 9% in patients > 60 years). Compared to our previous trial (AML-MDS Study 01-92) which was done with identical chemotherapy but no G-CSF priming in 110 patients with RAEB-T, AML after MDS, or secondary AML (identical median age, age range, and distribution of subtypes), the CR rate in all patients, as well as CR rate, overall survival, and relapse-free survival in patients > 60 years have significantly been improved. Thus, intensive chemotherapy with G-CSF priming is both well tolerated and highly effective for remission induction in these high-risk patients.

Acute Disease↗
PubMed2004

European consensus on diagnosis and treatment of germ cell cancer: a report of the European Germ Cell Cancer Consensus Group (EGCCCG).

Germ cell tumour is the most frequent malignant tumour type in young men with a 100% rise in the incidence every 20 years. Despite this, the high sensitivity of germ cell tumours to platinum-based chemotherapy, together with radiation and surgical measures, leads to the high cure rate of > or = 99% in early stages and 90%, 75-80% and 50% in advanced disease with 'good', 'intermediate' and 'poor' prognostic criteria (IGCCCG classification), respectively. The high cure rate in patients with limited metastatic disease allows the reduction of overall treatment load, and therefore less acute and long-term toxicity, e.g. organ sparing surgery for specific cases, reduced dose and treatment volume of irradiation or substitution of node dissection by surveillance or adjuvant chemotherapy according to the presence or absence of vascular invasion. Thus, different treatment options according to prognostic factors including histology, stage and patient factors and possibilities of the treating centre as well may be used to define the treatment strategy which is definitively chosen for an individual patient. However, this strategy of reduction of treatment load as well as the treatment itself require very high expertise of the treating physician with careful management and follow-up and thorough cooperation by the patient as well to maintain the high rate for cure. Treatment decisions must be based on the available evidence which has been the basis for this consensus guideline delivering a clear proposal for diagnostic and treatment measures in each stage of gonadal and extragonadal germ cell tumour and individual clinical situations. Since this guideline is based on the highest evidence level available today, a deviation from these proposals should be a rare and justified exception.

Europe↗
PubMed2003

Randomized phase III study of high-dose fluorouracil given as a weekly 24-hour infusion with or without leucovorin versus bolus fluorouracil plus leucovorin in advanced colorectal cancer: European organization of Research and Treatment of Cancer Gastrointestinal Group Study 40952.

PURPOSE: This trial was conducted to determine whether high-dose fluorouracil (FU) given as a weekly 24-hour infusion is more active than bolus FU + leucovorin (LV), and whether high-dose infusional FU can be modulated by LV. PATIENTS AND METHODS: A total of 497 patients with previously untreated metastatic colorectal cancer were randomly assigned to receive bolus FU 425 mg/m2 intravenously + LV 20 mg/m2 on days 1 to 5 and repeated on day 28 (FU + LV), or FU 2600 mg/m2 as a 24-hour infusion alone (FU24h) or in combination with 500 mg/m2 LV (FU24h + LV)-all given weekly x6 followed by a 2-week rest period. Survival was the major study end point. RESULTS: With a median follow-up of more than 3 years, survival did not differ among the treatment groups (median FU + LV, 11.1 months [95% CI, 10.2 to 15.0 months]; FU24h, 13.0 months [95% CI, 10.4 to 15.4 months]; FU24h + LV, 13.7 months [95% CI, 12.0 to 16.4 months]; P =.724). Progression-free survival (PFS) was significantly longer for FU24h + LV (median FU + LV, 4.0 months [95% CI, 3.4 to 4.9]; FU24h, 4.1 months [95% CI, 3.4 to 5.0]; FU24h + LV 5.6 months [95% CI, 4.4 to 6.7]; P =.029). The response rates in the subgroup of patients with measurable disease were 12%, 10%, and 17% for FU + LV, FU24h, and FU24h + LV, respectively (not significant). Occurrence of grade 3 and 4 diarrhea was higher in the FU24h + LV arm (22%) compared with the FU24h (6%) or FU + LV (9%) arms; however, stomatitis (11% in FU + LV v 3% in FU24h v 5% in FU24h + LV arms) and hematologic toxicity were higher in the bolus FU + LV arm. Global quality of life did not differ within the three arms. CONCLUSION: Neither FU24h + LV nor FU24h prolong survival, relative to bolus FU + LV. Leucovorin increases PFS if added to FU24h, but increases toxicity.

Adult↗
PubMed2002

Adjuvant treatment of colorectal cancer (current expert opinion derived from the Third International Conference: Perspectives in Colorectal Cancer, Dublin, 2001).

This article summarises the progress that has been made in the adjuvant treatment of colorectal cancer over the last decade. In view of the consequent improvements in recurrence rates and in overall survival, the development of effective adjuvant treatments for colorectal cancer is considered as one of the most important to be made in clinical oncology over the last decade. Treatment recommendations based on evidence-based data and on expert opinions are summarised in this manuscript. However, a consensus cannot be reached on all aspects of treatment because of data that is currently emerging that will influence clinical practice and because of the many ongoing clinical trials. Those involved in the treatment of colorectal cancer should therefore be encouraged to continue to provide optimal patient care and to participate in well designed clinical trials in order to increase the evidence upon which they can base their clinical judgements and in order to make further progress.

Antineoplastic Agents↗
PubMed2002

The role of oxaliplatin in the treatment of advanced metastatic colorectal cancer: prospects and future directions.

In the last 50 years, 5-fluorouracil-based therapy has been the mainstay of adjuvant and palliative treatment for colorectal cancer but response rates and median survival have been dismal despite the introduction of thymidylate synthase modulators such as leucovorin. Recently, new therapeutic approaches have been introduced. These include oral 5-fluorouracil analogues, pure thymidylate synthase inhibitors, dihydropyrimidine dehydrogenase inhibitors, and agents with mechanism of action unrelated to thymidylate synthase such as irinotecan, a topoisomerase I inhibitor, and oxaliplatin, the only platinum derivative with significant activity in colorectal cancer. Current treatment strategies involve combination therapies because this approach is the most effective. For instance, responses observed with oxaliplatin and 5-fluorouracil indicate synergy between the two agents and the combination of capecitabine plus oxaliplatin or irinotecan has shown high activity both in chemotherapy-naive and in pretreated patients with advanced colorectal cancer. Additionally, it is likely that future therapeutic management of advanced colorectal cancer may include combination therapy of one of the new oral 5-fluorouracil analogues, because of the convenient oral regimens. The identification of colorectal cancer-specific prognostic factors will undoubtedly influence treatment decisions. For instance, patients overexpressing epidermal growth factor receptor and p53 with thymidylate synthase have a worse prognosis. To target these biomarkers, antibodies such as cetuximab, an anti-EGFR antibody, and angiogenesis inhibitors and tyrosine kinase inhibitors have been introduced and are undergoing clinical evaluation. Over the last 5 years the armamentarium to fight colorectal cancer has increased significantly, giving more hope for effective disease management.

Antineoplastic Agents↗
PubMed2002

A new chemoembolization protocol in refractory liver metastasis of colorectal cancer--a feasibility study.

INTRODUCTION: In patients with advanced colorectal cancer (CRC) refractory to systemic chemotherapy including 5-fluorouracil (5-FU) / folinic acid (FA), oxaliplatin and irinotecan we assessed the feasibility, toxicity and response to hepatic transcatheter arterial chemoembolization (TACE). At the time of treatment, patients had exclusively or dominantly liver metastasis of CRC. PATIENTS AND METHODS: The following protocol was applied via a selective transfemoral hepatic arterial approach: mitomycin C 5 mg/m(2), interferon-alpha2b 4.5 Mio IU, dexamethasone 20 mg mixed with Amilomer DSM 45/25 (Spherex((R))) days 1 and 2 i.a. (bolus), oxaliplatin 50 mg/m(2) (2 h) day 1 i.a., FA 500 mg/m(2) (2 h) day 1 i.v., and 5-FU 1.500 mg/m(2) (24 h) day 1 i.a. Cycles have been repeated at days 15-22. The dose was adjusted according to the pretreatment performance status and elevation of alkaline phosphatase, bilirubin and serum albumin. Treatment was continued until progression or emergence of intolerable toxicity. RESULTS: 11 patients received a total number of 43 TACE, with a range of 2-6 per patient. There was no TACE-related mortality. 4 patients died 5, 8, 10 and 11 months after initiation of treatment due to progression of disease. 7 patients are alive at 4+ (n = 2), 5+ (n = 1), 6+ (n = 1), 7+ (n = 1) and 11+ (n = 2) months after start of treatment. Toxicity (CTC) was mild with grade I-II asthenia (n = 10), grade I-II neurotoxicity (n = 5), grade II nausea and/or vomiting (n = 2) and grade II diarrhea (n = 1). Treatment had to be postponed due to grade I thrombocytopenia in 2 patients. No bleeding episodes or obvious infectious complications occurred during treatment intervals. 1 patient experienced an allergic reaction to oxaliplatin which led to exclusion from further therapy. Arterial catheter dislocation occurred in 3 patients. In 10 patients evaluable for response we observed 3 partial responses, 2 minor responses, and 4 times stable disease. Only 1 patient had further progression of disease under treatment. CONCLUSION: TACE, using a combination of mitomycin C, dexamethasone and interferon-alpha2b mixed with Spherex((R)), followed by oxaliplatin, FA and 5-FU, appears to be an effective and feasible treatment option in the case of liver metastasis of CRC refractory to standard systemic chemotherapy. This treatment is associated with tolerable toxicity, which becomes apparent mainly as asthenia, neurotoxicity or thrombocytopenia. These preliminary data warrant further evaluation for patients with refractory disease and would probably also be of interest for first-line treatment in this patient population.

Adult↗
PubMed2001

[Possible new indications for erythropoietin therapy].

The use of hematopoietic growth factors has increased rapidly during the last decade. Among the growth factors available, erythropoietin (EPO) was the first growth factor to be used clinically. To date, EPO has shown activity in the treatment of the tumor-associated anemia and for correction of tumor hypoxia, however, when compared with transfusion of erythrocytes EPO treatment did not significantly prolong survival in cancer patients in any published study so far. Recently, novel extramedullary EPO receptors have been identified leading to a better understanding of the molecular mechanisms of action of EPO. Results from these experiments and from several clinical studies suggest that EPO treatment may be beneficial for patients with (chronic) infections (HIV, inflammatory bowel disease, septic episodes) and for treatment of the fatigue syndrome following cancer chemotherapy. In addition, EPO may also improve stem cell engraftment following high-dose chemotherapy and can increase survival rates of patients with aplastic anemia and myelodysplastic syndrome. Currently, new EPO derivatives, synthetic fusion proteins and gene therapeutic studies are under clinical investigation suggesting that the EPO-induced effects may be increased significantly by these agents in the future.

Anemia, Aplastic↗
PubMed2001

Viable malignant cells after primary chemotherapy for disseminated nonseminomatous germ cell tumors: prognostic factors and role of postsurgery chemotherapy--results from an international study group.

PURPOSE: To assess the value of postsurgery chemotherapy in patients with disseminated nonseminomatous germ-cell tumors (NSGCTs) and viable residual disease after first-line cisplatin-based chemotherapy. PATIENTS AND METHODS: The outcome of 238 patients was reviewed. Tumor markers had normalized in all patients before resection. A multivariate analysis of survival was performed on 146 patients. RESULTS: The 5-year progression-free survival (PFS) rate was 64% and the 5-year overall survival (OS) rate was 73%. Three factors were independently associated with both PFS and OS: complete resection (P <.001), < 10% of viable malignant cells (P =.001), and a good International Germ Cell Consensus Classification (IGCCC) group (P =.01). Patients were assigned to one of three risk groups: those with no risk factors (favorable group), those with one risk factor (intermediate group), and those with two or three risk factors (poor-risk group). The 5-year OS rate was 100%, 83%, and 51%, respectively (P <.001). The 5-year PFS rate was 69% (95% confidence interval [CI], 62% to 76%) and 52% (95% CI, 40% to 64%) in postoperative chemotherapy recipients and nonrecipients, respectively (P <.001). No significant difference was detected in 5-year OS rates. After adjustment on the three prognostic factors, postoperative chemotherapy was associated with a significantly better PFS (P <.001) but not with better OS. Patients in the favorable risk group had a 100% 5-year OS, with or without postoperative chemotherapy. Postoperative chemotherapy appeared beneficial in both PFS (P <.001) and OS (P =.02) in the intermediate-risk group but was not statistically beneficial in the poor-risk group. CONCLUSION: A complete resection may be more critical than recourse to postoperative chemotherapy in the setting of postchemotherapy viable malignant NSGCT. Immediate postoperative chemotherapy or surveillance alone with chemotherapy at relapse may be reasonable options depending on the completeness of resection, IGCCC group, and percent of viable cells. Validation is necessary.

Adult↗
PubMed2001

Extragonadal seminoma: an international multicenter analysis of prognostic factors and long term treatment outcome.

BACKGROUND: The objectives of this study were to evaluate the long term outcome of patients with extragonadal seminomatous germ cell tumors (GCT) so that prognostic variables for disease recurrence and patient survival could be identified and to access the efficacy of different treatment modalities. METHODS: Six hundred thirty-five patients with extragonadal GCT who were treated consecutively at 11 centers in the United States and Europe during the cisplatin-based chemotherapy era between 1975 and 1996 were evaluated retrospectively. RESULTS: Fifty-two patients with primary retroperitoneal GCT (50%) and 51 patients with primary mediastinal GCT (49%) of pure seminomatous histology were identified (n = 1 patient with a primary cervical lymph node) representing 16.4% of 635 patients with extragonadal GCT who were included in the data base. The median age was 37 years (range, 18-70 years). Treatment consisted of platin-based chemotherapy in 77 patients (74%), radiotherapy in 9 patients (9%), and combined modality in 18 patients (17%). Ninety-two percent of patients (95% confidence interval, 87-97%) achieved a favorable response to primary therapy. After a median follow-up of 61 months (range, 1-211 months), 18 patients (17%) have had recurrent disease: 14% of those who received chemotherapy and 67% of those who received radiation therapy. The 5-year progression free survival rate favored the chemotherapy group, with 87% compared with 33% for irradiated patients (P = 0.006), whereas the overall survival rates were equal (90% vs. 67%; P = 0.13). No differences in overall survival or progression free survival were observed among patients with primary retroperitoneal and mediastinal seminoma. Prognostic factors that were identified to influence survival negatively were liver metastases (P = 0.01) and two or more metastatic sites (P = 0.04). CONCLUSIONS: In patients with extragonadal seminoma, a survival rate of > 90% at 5 years is achieved with adequate cisplatin-based chemotherapy. Compared with patients with nonseminomatous extragonadal GCT, no difference in long term survival exists between patients with primary retroperitoneal or mediastinal seminoma location. Primary radiotherapy seems to be associated with a significantly higher rate of disease recurrence, although most patients will be salvaged by subsequent chemotherapy.

Adolescent↗
PubMed2001

Second-line chemotherapy in patients with relapsed extragonadal nonseminomatous germ cell tumors: results of an international multicenter analysis.

PURPOSE: Relapsed extragonadal germ cell tumors patients (EGGCT) are treated with identical salvage chemotherapy regimens, as are patients with metastatic testicular cancer. This investigation evaluates the results of second-line chemotherapy in nonseminomatous EGGCT and tries to identify prognostic factors for survival. PATIENTS AND METHODS: We conducted a retrospective review of 142 patients treated at eleven European and American centers between 1975 and 1996. All had received cisplatin-containing regimens as induction treatment. RESULTS: Twenty-seven of 142 patients (19%) were long-term disease-free, 11% with primary mediastinal and 30% of patients with primary retroperitoneal disease. Median follow-up since start of salvage treatment was 11 months (range, 1 to 157) for all patients and 45 months (range, 6 to 157) for surviving patients. Forty-eight patients (34%) received high dose chemotherapy with autologous bone marrow transplant at relapse, and 10 of these patients (21%) are continuously disease-free. Primary mediastinal location (P =.003), sensitivity to cisplatin (P =.003), elevated beta-HCG at relapse (P: =.04), and normal LDH at diagnosis (P =.01) were shown to be significant negative prognostic factors for overall survival in univariate; mediastinal location [relative risk ratios (HR) = 1.9; 95% confidence intervals (CI), 1.2 to 3.0] and sensitivity to cisplatin [HR = 2.4; 95% CI, 1.1 to 5.2] were significant negative prognostic factors in multivariate analysis. CONCLUSION: Although current salvage strategies will cure between 20% and 50% of recurrent metastatic testicular cancer, relapsed nonseminomatous EGGCT patients appear to have an inferior survival rate, in particular in case of primary mediastinal location. Mediastinal primary tumor and inadequate response to cisplatin-based induction chemotherapy have been identified as independent negative prognostic factors, both associated with an approximately two-fold higher risk for failure of salvage treatment.

Adolescent↗
PubMed2001

Salvage treatment with paclitaxel, ifosfamide, and cisplatin plus high-dose carboplatin, etoposide, and thiotepa followed by autologous stem-cell rescue in patients with relapsed or refractory germ cell cancer.

PURPOSE: To study feasibility and efficacy of a new salvage regimen in patients with relapsed and/or refractory germ cell tumors. PATIENTS AND METHODS: Between May 1995 and February 1997, 80 patients were entered onto a phase II study. Conventional-dose salvage treatment with three cycles of paclitaxel 175 mg/m(2), ifosfamide 5 x 1.2 g/m(2), and cisplatin 5 x 20 mg/m(2) (TIP) was followed by one cycle of high-dose chemotherapy (HDCT) with carboplatin 500 mg/m(2) x 3, etoposide 600 mg/m(2) x 4, and thiotepa 150 to 250 mg/m(2) x 3 (CET). In 23 patients, one additional cycle of paclitaxel 175 mg/m(2) and ifosfamide 5 g/m(2) (TI) was given immediately before TIP to improve stem-cell mobilization. RESULTS: Fifty-five (69%) of 80 patients responded to TIP, 24 (30%) of 80 patients had stable disease (n = 5) or tumor progression (n = 19), and one patient died. Only 62 (78%) of 80 patients received subsequent HDCT. Among those, 41 (66%) of 62 patients responded and 20 (32%) of 62 patients had stable disease (n = 3) or tumor progression (n = 17). One patient died after HDCT from multiorgan failure. Survival probabilities at 3 years were 30% for overall and 25% for event-free survival. Peripheral neurotoxicity with sensorimotor impairment grade 2 through 4 in 29%, paresthesias grade 2 through 4 in 24%, and skin toxicity grade 2 through 3 in 15% of patients were the most relevant side effects. CONCLUSION: Treatment with TIP followed by high-dose CET is feasible and can induce long-term remissions in 25% of patients with relapsed or refractory germ cell tumors. Peripheral nervous toxicity in approximately one third of patients is a disadvantage of this salvage strategy.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2001

A low dose of ionizing radiation increases luminal release of intestinal peptidases in rats.

PURPOSE: Mucosal inflammation in the small intestine is a potentially hazardous side effect of abdominal irradiation. In an effort to develop a quantitative method of evaluating mucosal damage, the luminal release of brush border enzymes in response to ionizing radiation was examined using two investigational strategies. METHODS: First, a 20 cm segment of the proximal jejunum was perfused in situ and enzymatic activities within the perfusates were evaluated. In a second approach, enzymatic activities were directly evaluated in isolated brush border membranes from the jejunal mucosa. RESULTS: Most of the peptidase activities measured were increased in the perfusates 1 day after irradiation and had returned to control levels at 4 days. In the brush border membranes, some enzyme activities decreased at 1 day and were, with the exception of leucineaminopeptidase (LAP), similar to control levels at 4 days. CONCLUSIONS: LAP is more strongly affected by radiation than the transmembranously bounded enzymes.

Animals↗
PubMed2001

Cyclooxygenase-2: a novel target for cancer chemotherapy?

Epidemiologic studies have documented a 40-50% reduction in incidence of colorectal cancer in individuals taking nonsteroidal antiinflammatory drugs (NSAIDs). Since NSAIDs are known to inhibit cyclooxygenases (COX-1, COX-2), the basic mechanism of their antitumor effects is conceivably the altered metabolism of arachidonic acid and, subsequently, prostaglandins (PGs). Although COX-2, the inducible isoform, is regularly expressed at low levels in colonic mucosa, its activity increases dramatically following mutation of the APC (adenomatous polyposis coli) gene suggesting that beta-catenin/T-cell factor mediated Wnt-signaling activity may regulate COX-2 gene expression. In addition, hypoxic conditions and sodium butyrate exposure may also contribute to COX-2 gene transcription in human cancers. The development of selective COX-2 inhibitors has made it possible to further evaluate the role of COX-2 activity in colorectal carcinogenesis. To date, at least five mechanisms by which COX-2 contributes to tumorigenesis and the malignant phenotype of tumor cells have been identified, including: (1) inhibition of apoptosis; (2) increased angiogenesis; (3) increased invasiveness; (4) modulation of inflammation/immuno-suppression; and (5) conversion of procarcinogens to carcinogens. A clear positive correlation between COX-2 expression and inhibition of apoptosis has been established, associated with increased PGE2 levels resulting in modulation of pro- and anti-apoptotic factors (e.g., bcl-2, MAKs/ras, caspase-3, Par-4). In terms of angiogenesis and invasiveness, COX-2 activity was found to increase the expression of growth factors (e.g., VDEG, PDGF, bFGF) and matrix metalloproteinases (MMPs). Since COX-2 inhibitors have been demonstrated to interfere with tumorigenesis and apoptosis, COX-2 and its gene product may be attractive targets for therapeutic and chemoprotective strategies in colorectal cancer patients. This may lead to new perspectives that by controlling the cancer phenotype, rather than attempting to eradicate all affected cells, may provide significant benefits to the cancer patient.

Anti-Inflammatory Agents, Non-Steroidal↗