Spatial occupancy patterns and activity of arid rangeland cattle grazing small riparian pastures.

The spatial occupancy patterns and activity of cattle grazing three riparian pastures was investigated in northeastern Oregon using Global Positioning System (GPS) collars logging at 1-sec intervals. Cattle consistently selected plant communities as grazing areas that had forage in sufficient volume to meet their requirements and favored communities as resting areas that were dry and open. Cattle were stationary for more than 50% of the time in each pasture and consistently rested between dark and 04:00 hours. Interaction with stream channels was found to be 1-2% of total occupancy time and occurred on less than 10% of channel length. Cattle were indifferent or avoided channel areas relative to their area and, when in this zone, they spent most of their time moving not resting. Cattle did not prefer the stream bank zone and spent only 2% of their time in that zone. When occupied, the stream bank zone was used as a travel corridor to gain access to water or cross the channel to access other pasture areas. These results are in contrast with the general belief that cattle are a primary occupant of the stream bank/channel area; additional research is needed to define factors influencing cattle occupancy.

Management of Stages I and II Nonseminomatous Germ Cell Tumors of the Testis.

Management of Stages I and II nonseminomatous tumors of the testis is in a state of flux as a result of improvement in the major modalities for patient treatment. Both radiotherapy and retroperitoneal lymphadenectomy, used alone, are providing five-year survival rates in the range of 75 to 90% for patients with localized disease (Stage 1). However, since current staging methods fail to detect regional disease (Stage II) in 15 to 20% of the patients before therapy, lymphadenectomy provides a distinct and additional advantage, both by removing possible unseen metastases and by determining pathologically which patients may benefit from adjuvant therapy. Both surgery and radiotherapy, when used alone to combat extensive retroperitoneal disease, have proved unsatisfactory; surgery is frequently difficult or impossible, and persistent disease is common following radiotherapy. Therefore, patients with extensive Stage II disease are best treated with either preoperative chemotherapy or preoperative radiotherapy (2500 to 3000 rads over three to four weeks) before resection of the retroperitoneal disease. The benefits of adjuvant chemotherapy for patients with Stages I and II disease is under continuing investigation.

Chemotherapy Programs of the National Prostatic Cancer Project (NPCP).

Results of the first nationally randomized trial of the National Prostatic Cancer Project revealed a demonstrable advantage for chemotherapy in the management of advanced disease (Stage D in relapse from endocrine therapy). Both cyclophosphamide and 5-Fluorouracil showed improved activity over standard therapy. A second trial for patients previously irradiated, with less tolerance to myelosuppressive agents, revealed an advantage for estramustine phosphate and streptozotocin over standard therapy. Subsequently completed trials have revealed activity for prednimustine and imidazole carboxamide (DTIC). Trials currently underway for newly-diagnosed Stage D and for Stage D disease clinically stable to diethylstilbestrol (DES) show promising activity for DES combined with cyclophosphamide. Current trials with single agents in advanced disease are comparing methyl-CCNU and hydroxyurea with cyclophosphamide; another is evaluating estramustine phosphate and vincristine alone and in combination. The use of chemotherapy in earlier staged patients as adjuvants to definitive surgery or irradiation is underway in two clinical trials, where the effect of cyclophosphamide and estramustine phosphate as long-term therapies is compared with no additional treatment.