Discovery of novel hit compounds with broad activity against visceral and cutaneous Leishmania species by comparative phenotypic screening.

The limited success of recent phenotypic anti-leishmanial drug screening campaigns calls for new screening strategies for the discovery of clinically relevant hits. Here we present such a novel strategy based on physiologically relevant, ex vivo biology. We established high content phenotypic assays that combine primary murine macrophages and lesion-derived, virulent L. donovani and L. amazonensis amastigotes, which we applied to validate previously identified, anti-leishmanial hit compounds referred to as 'GSK Leish-Box'. Together with secondary screens using cultured promastigotes, our pipeline distinguished stage- and/or species-specific compounds, including 20 hits with broad activity at 10 µM against intracellular amastigotes of both viscerotropic and dermotropic Leishmania. Even though the GSK Leish-Box hits were identified by phenotypic screening using THP-1 macrophage-like cells hosting culture-derived L. donovani LdBob parasites, our ex vivo assays only validated anti-leishmanial activity at 10 µM on intra-macrophagic L. donovani for 23 out of the 188 GSK Leish-Box hits. In conclusion, our comparative approach allowed the identification of hits with broad anti-leishmanial activity that represent interesting novel candidates to be tested in animal models. Physiologically more relevant screening approaches such as described here may reduce the very high attrition rate observed during pre-clinical and clinical phases of the drug development process.

Early postoperative enteral immunonutrition: clinical outcome and cost-comparison analysis in surgical patients.

OBJECTIVE: To determine if early postoperative feeding of patients with upper gastrointestinal malignancy, using an enteral diet supplemented with arginine, dietary nucleotides, and omega-3 fatty acids (IMPACT, Sandoz Nutrition, Bern, Switzerland) results in an improved clinical outcome, i.e., reduced infectious and wound complications and decreased treatment costs when compared with an isocaloric, isonitrogenous control diet. DESIGN: A prospective, randomized, placebo-controlled, double-blind, multicenter trial of the clinical outcome and a retrospective cost-comparison analysis. SETTING: Surgical intensive care units in three different German university hospitals. PATIENTS: Of 164 patients enrolled in the study, 154 patients were eligible for analysis. They were admitted to the intensive care unit after upper gastrointestinal surgery for cancer and they received an enteral diet via needle catheter jejunostomy. Infectious complications were defined as sepsis or systemic inflammatory response syndrome, pneumonia, urinary tract infection, central venous catheter sepsis, wound infection, and anastomotic leakage. The complication events were prospectively divided into two groups: early (postoperative days 1 to 5) and late (after the fifth postoperative day) postoperative complications. The treatment costs of each complication were analyzed and compared in both groups. INTERVENTIONS: Patients were randomized to receive either the immunonutritional diet (n = 77) or an isocaloric and isonitrogenous placebo diet (n = 77). Enteral feeding was initiated 12 to 24 hrs after surgery, starting with 20 mL/hr and advanced to a target volume of 80 mL/hr by postoperative day 5. MEASUREMENTS AND MAIN RESULTS: Clinical examination and adverse gastrointestinal symptoms were recorded on a daily basis. Both groups tolerated early enteral feeding well, and the rate of tube feeding-related complications was low. Postoperative complications occurred in 17 patients in the immunonutrition group vs. 24 patients in the control group (NS). Further, in the early phase (postoperative day 1 to 5), complications occurred to a similar extent in both groups (12 patients in the immunonutritional group vs. 11 patients in the control group). However, in the late phase (after postoperative day 5), considerably fewer patients in the experimental diet group experienced complications compared with the control group (5 vs. 13, p < .05). In addition, the frequency rate of complicating events were recorded in each group. In the experimental diet group, a total of 22 complicating events were recorded vs. a total of 32 events in the placebo diet group (NS). However, the occurrence of late complicating events, i.e., complicating events after the fifth postoperative day, was significantly reduced in the immunonutrition group when compared with the control group (8 vs. 17 events, p < .05). The total costs for the treatment of the complications were 83,563 German marks in the experimental diet group vs. 122,430 German marks in the control group, resulting in a cost-reduction of 38,867 German marks. (At the end of December 1995, the conversion rate from German marks to U.S. dollars was 1.4365 German marks to $1.00.) CONCLUSIONS: Early enteral feeding with an arginine, dietary nucleotides, and omega-3 fatty acids supplemented diet, as well as an isonitrogenous, isocaloric control diet (placebo) were well tolerated in patients who underwent upper gastrointestinal surgery. In patients who received the supplemented diet, a significant reduction in the frequency rate of late postoperative infectious and wound complications was observed. Thereby, the treatment costs were substantially reduced in the immunonutrition group as compared with the control group.

"High-dose" radioiodine therapy in advanced differentiated thyroid carcinoma.

UNLABELLED: There is yet no consensus concerning the appropriate regimen of the application of [131I]sodium iodine (Nal) activities to patients suffering from advanced differentiated thyroid carcinoma. We report on a total of 167 applications of [131I]Nal, including 78 applications of 11.1 GBq. Response to high-activity radioiodine therapy (RIT) is correlated to the course of the disease as well as to the reaction of thyreoglobulin and acute/subacute side effects of radiation. METHODS: Following radioablation of thyroid remnants using 1.85 to 3.7 GBq[131I]Nal, 26 patients with advanced differentiated thyroid carcinoma (follicular, 11; papillary, 4;mixed-cell thyroid carcinoma, 11) were treated with repeated activities of 11.1 GBq[131I]Nal. Initial tumor staging according to UICC showed T4 in 54%, T3 in 19%, T2 in 19% and was not obtained in 8%. Differentiated thyroid carcinoma was multifocal in 23% of patients. Applied accumulated activities ranged from 14.8 to 99.9 GBq with a mean of 55.5 GBq per patient. RESULTS: Mean post-diagnostical follow-up was 73 mo, mean follow-up after diagnosis of metastatic spread was 48 mo. Follicular thyroid carcinoma remained as stable disease in 7 of 11 patients, 6 of whom showed metastatic disease after a mean of 20 mo, and only 1 complete remission was achieved using high-dose therapies, with progressive disease in the remaining patients. Overall, 73% of follicular thyroid carcinoma had progressive disease without major response to high-activity RIT. In contrast, only 20% of papillary thyroid carcinoma/mixed-cell thyroid carcinoma showed progressive disease, and complete remission was achieved in 47% of patients. Pulmonary and lymph node metastases in the majority of patients showed good response to therapy, whereas local recurrences and bone metastases showed minor reactions to RIT. After low-activity therapies 8% of patients showed WHO grade I hematotoxic reactions. After high-activity therapies, 38% of patients had WHO I, 8% WHO II and one patient had WHO III toxicity (4%). CONCLUSION: Use repetitive high-activity RIT with a maximum of 44.4 GBq applied during 1 yr and a maximum of 99.9 GBq accumulated activity resulted in a significant increase of hematotoxicity. However, during the follow-up period (mean, 4 yr), no clinical symptoms possibly related to low blood counts were seen in patients with advanced differentiated thyroid carcinoma. Initiation of high-activity RIT in reaction to metastatic tumor outspread to achieve complete remission was found to be useful in treating papillary thyroid carcinoma and mixed-cell thyroid carcinoma, but only in a minority of follicular thyroid carcinoma patients.

[Changes in the blood picture after radioiodine therapy of thyroid cancer]. / Blutbildveränderungen nach Radiojodtherapie bei Schilddrüsenkarzinomen.

AIM: In this study the effect of radioiodine which was administered because of thyroid carcinoma on blood count and various other parameters was examined. PATIENTS AND METHODS: In 567 patients who had been treated because of a thyroid carcinoma between 1980 and 1990 with radioiodine, changes of hemoglobin, RBC, WBC, platelets, potassium, uric acid, gamma GT, GOT, GPT and AP were measured in correlation with the totally administered dose. RESULT: In low doses (< 18.5 GBq [500 mCi]), which are sufficient in most cases with clinical course without complications, relevant changes of blood count (hemoglobin: < or = 9.0/10.5 g/dl, RBC: < or = 3.1/3.5 10(12)/l (female/male), WBC: < or = 2.5 10(9)/l, platelets: < or = 0.5 10(11)/l) were observed in only 5 out of 469 cases. After moderate doses (> or = 18.5 GBq [500 mCi] and < 37 GBq [1000 mCi]) we found in only 1 out of 77 cases relevant changes. After very high doses (> or = 37 GBq [1000 mCi]), which are used to treat metastases and/or recurrences, thrombopoesis is most sensitive to the radiation exposure of the bone marrow. Relevant decrease of RBC and WBC were observed in 2 out of 21 patients. Pancytopenia (hemoglobin: < or = 12.0/13.5 g/dl, RBC: < or = 3.9/4.3 10(12)/l [female/male], WBC: < or = 3.5 10(9)/l, platelets: < or = 1.4 10(11)/l) occurred in 4 cases. CONCLUSION: In high-dose therapy with radioiodine frequent (monthly, but in any cases before each therapy) controls of blood count are necessary. In patients without metastases or recurrence no relevant changes can be expected in most cases.