Nitrate leaching beneath a containerized nursery crop receiving trickle or overhead irrigation.

Container production of nursery crops is intensive and a potential source of nitrogen release to the environment. This study was conducted to determine if trickle irrigation could be used by container nursery producers as an alternative to standard overhead irrigation to reduce nitrogen release into the environment. The effect of overhead irrigation and trickle irrigation on leachate nitrate N concentration, flow-weighted nitrate N concentration, leachate volume, and plant growth was investigated using containerized rhododendron (Rhododendron catawbiense Michx. 'Album') supplied with a controlled-release fertilizer and grown outdoors on top of soil-monolith lysimeters. Leachate was collected over two growing seasons and overwinter periods, and natural precipitation was allowed as a component of the system. Precipitation accounted for 69% of the water entering the overhead-irrigated system and 80% of the water entering the trickle-irrigated system. Leachate from fertilized plants exceeded the USEPA limit of 10 mg L(-1) at several times and reached a maximum of 26 mg L(-1) with trickle irrigation. Average annual loss of nitrate N in leachate for fertilized treatments was 51.8 and 60.5 kg ha(-1) for the overhead and trickle treatments, respectively. Average annual flow-weighted concentration of nitrate N in leachate of fertilized plants was 7.2 mg L(-1) for overhead irrigation and 12.7 mg L(-1) for trickle irrigation. Trickle irrigation did not reduce the amount of nitrate N leached from nursery containers when compared with overhead irrigation because precipitation nullified the potential benefits of reduced leaching fractions and irrigation inputs provided under trickle irrigation.

Small intestinal angiodysplasia in the elderly.

The predominant site of bleeding intestinal angiodysplasia in elderly patients will be the cecum or ascending colon, but recent experience in the Yale-Affiliated Gastroenterology Program in 1 year indicates that elderly patients may have bleeding acquired angiodysplasia (AD) confined to the small intestine only. A review of the literature confirms that symptomatic small intestinal AD is infrequent and occurs at an average age of 32 years in some series. Five patients with symptomatic small intestinal AD diagnosed during 1981 at Yale were older, with an average of 62 years. Three of the five cases (all female) had lesions in the duodenum, with two (males) having lesions in the ileum. Noncolonic AD in the elderly may be acquired during life, as in the classic situation in the right colon, but may be difficult to distinguish clinically and pathologically from the vascular lesions of hereditary hemorrhagic telangiectasia.

Gastrointestinal angiodysplasia: a possible component of von Willebrand's disease.

Evidence in the literature suggests that von Willebrand's disease constitutes part of a mesenchymal syndrome accompanied by coagulopathy. The cases of two patients with symptomatic intestinal angiodysplasia and concurrent von Willebrand's disease are summarized along with the eight cases previously reported in the literature. All ten cases were in adults ranging in age from 34 to 80 years (average, 58 years). The vascular lesions were located in the stomach or duodenum (four cases), right colon (three cases), and terminal ileum (two cases). One patient had angiodysplasia of the stomach, jejunum, and sigmoid colon. While the prevalence is unknown, these ten cases linking gastrointestinal angiodysplasia with von Willebrand's disease appear to reflect an association greater than more coincidence. Coagulation testing, including determination of template bleeding time and partial thromboplastin time, should probably be performed in all patients bleeding from gastrointestinal angiodysplasia to screen for von Willebrand's disease.

Campylobacter enterocolitis.

We report four patients with bloody diarrhea and colitis from Campylobacter fetus subspecies jejuni. Two patients had dogs with Campylobacter fetus in their stools. All patients responded rapidly and completely to erythromycin therapy. Campylobacter fetus subspecies jejuni is now a relatively common cause of enterocolitis, more common than salmonella or shigella. When the organism causes short-lived water diarrhea, a definitive diagnosis is not necessary. In a patient with bloody diarrhea and acute colitis, the clinician should pursue Campylobacter fetus as a potential offender, recognizing that acute colitis from Campylobacter fetus is clinically and and pathologically indistinguishable from any other acute colitis.

The protean gastrointestinal manifestations of metastatic breast carcinoma.

Metastatic breast carcinoma commonly remains silent for many years following initial diagnosis and mastectomy, and then appears as metastases at various locations. Gastrointestinal involvement is not uncommon and includes any site along the whole length of the gut, the liver, and the biliary tree; it occasionally simulates other diseases and causes difficulty in diagnosis. The radiographic features and differential diagnoses are discussed.