Dynamics of ammonia volatilization from simulated urine patches and aqueous urea applied to pasture. III. Field verification of a simplified model

Published field experimental data [11, 15, 19] were used to compare measured NH_3(g) losses following applications of urine or aqueous urea to pasture soils with values predicted by a simplified ammonia volatilization model [16]. Total measured losses were generally in close agreement with predictions. For example, predicted losses following applications of urine to a ryegrass-white clover pasture in Canterbury, New Zealand were 20.7% in summer and 22.4% in autumn and were highly correlated with measured losses of 21.5% and 24.4% respectively (r = 0.998).The model was also tested for instantaneous rate of ammonia gas loss at 33 discrete sampling times for the summer experiment. Correlations were again highly significant (r = 0.951 for urine and r = 0.885 for urea).The interception of urine solution by herbage and litter on the pasture surface is discussed and was shown to account for some of the discrepancies between measurements and predictions. Soil surface pH was confirmed as an important factor in determining the extent of ammonia gas loss, and the practicalities of measuring this parameter under field conditions are presented. It was concluded that the model offers the potential for predicting ammonia volatilization losses following urine or aqueous urea applications to short pasture in non-leaching, non-nitrifying environments.     

Hormone changes in relation to the time of fetal death after prostaglandin-induced abortion

The changes in unconjugated estradiol-17beta and estriol, progesterone and chorionic somatomammotropin (HCS) in peripheral plasma have been studied in 18 women at 30-minute intervals following intra-uterine prostaglandin E2 administration for therapeutic termination of second trimester pregnancy. The hormonal changes were related to the time of fetal death detected by the disappearance of fetal heart pulsations. Prostaglandin E2 was given by the intra-amniotic route with urea (5 patients) or with intravenous oxytocin (5 patients), or by the extra-amniotic route with intravenous oxytocin (8 patients). Fetal death occurred rapidly with intra-amniotic PGE2, but usually at a late stage with extra-amniotic PGE2. Three fetuses in the extra-amniotic group died at or just before abortion. A variety of fetal heart changes were noted and the time of fetal death did not appear to influence the time of abortion within each treatment subgroup. Estradiol and estriol showed a sligh but persistent fall over 24 hours prior to induction of abortion. A more rapid fall usually occurred after induction, with a consistent fall around the time of fetal death. Progesterone and HCS usually fell much less before and immediately after fetal death. A marked rise in estradiol sometimes occurred before fetal death, particularly in the intraamniotic PGE2 and urea subgroup. Estriol levels declined more rapidly before than after fetal death, whereas fetal death had less consistent effects on the other hormones. All hormones had usually fallen considerably at the time of abortion, and in some individuals marked fluctuations in hormone levels were seen.     

Kinetics of populations of enterocytes of experimental tumors of the large intestine in rats

To determine whether somatostatin, an inhibitor of glucagon and growth hormone secretion, might be useful as an adjunct to insulin the management of diabetic hyperglycaemia, seven insulin-requiring diabetic men were given somatostatin (100 microgram/h, IV) continuously for 3 days after their diabetes had been treated intensively by diet and insulin on a metabolic ward. During infusion of somatostatin and despite reduction in average insulin dose exceeding 50%, there was improvement in diabetic control as assessed by postprandial hyperglycaemia, 24-h glycosuria and the average daily serum glucose level and its fluctuation; when somatostatin was discontinued, but insulin doses held constant, diabetic control rapidly worsened. No adverse effects were observed. These results indicate that somatostatin plus insulin can be a more effective regimen than insulin alone in controlling diabetic hyperglycaemia. A longer acting and more selective somatostatin preparation may prove useful as an adjunct to insulin in the management of diabetes.     

Hilar cholangiocarcinoma: thin-section spiral CT findings with cholangiographic correlation

Hilar cholangiocarcinoma, a highly lethal tumor, is difficult to diagnose with conventional computed tomography (CT) because of its small size. Spiral CT allows more effective evaluation of these small lesions and better demonstrates the status of the hepatic arterial or portal venous circulation. Among 27 patients with hilar cholangiocarcinoma (infiltrative in 21, exophytic in two, polypoid in one, diffuse in three), thin-section spiral CT allowed identification of each tumor as an area of focal wall thickening that obliterated the lumen. Seventeen of the infiltrative tumors (81%) showed high attenuation. Identification of the level of biliary obstruction was possible in 63% of the patients (17 of 27). The level of obstruction was underestimated in six patients and overestimated in four. Spiral CT is a valuable method for diagnosis of hilar cholangiocarcinoma; however, spiral CT is less accurate in evaluation of intraductal tumor extent because of the limited z-axis resolution.     

Increased restenosis in diabetes mellitus after coronary interventions is due to exaggerated intimal hyperplasia. A serial intravascular ultrasound study

Hepatic hydrothorax is a rare complication of portal hypertension. Conservative therapy may be successful but refractory hepatic hydrothorax is not uncommon. Management of refractory hydrothorax is usually ineffective and can result in a worsened clinical status. Transjugular intrahepatic portosystemic shunts (TIPS) lower portal pressure and have been used in the treatment of refractory ascites. The aim of this study was to determine the efficacy of TIPS in the treatment of symptomatic refractory hepatic hydrothorax. A TIPS was placed in 24 consecutive cirrhotic patients with symptomatic refractory hepatic hydrothorax. Five patients (20.8%) were Child's/Pugh class B and 19 (79.2%) were class C. All had undergone multiple thoracenteses and were hypoalbuminemic. Mean follow-up was 7.2 months (range, 0.25-49 months). Fourteen (58.3%) of 24 patients had complete relief of symptoms after shunt placement and did not require further thoracentesis. Five (20.8%) additional patients required fewer thoracenteses. Five (20.8%) patients developed worsening liver function and died within 45 days. In eight (66.7%) of 12 patients with > or = 60 days of follow-up, the serum albumin increased by a mean of 1.2 g/dL (range, 0.1-2.2 g/dL). The Child's-Pugh score improved in 7 (58.3%) of these 12 patients and two patients improved from class C to class A. These two patients no longer require liver transplantation. This study shows that TIPS can be effective in the management of symptomatic, refractory hepatic hydrothorax. Clinical and laboratory improvement may be seen and liver transplantation may become unnecessary.     

Duration of homologous porcine reproductive and respiratory syndrome virus immunity in pregnant swine

The clinical consequences of single or multiple exposure of pregnant gilts to porcine reproductive and respiratory syndrome virus (PRRSV) at various stages of gestation were determined. Thirty-three pregnant gilts were allotted to 6 experimental groups (5 to 7 gilts/group). Gilts of groups 1 to 5 were exposed to strain NADC-8 of PRRSV at the following times: group 1, gestation day (GD) 1; group 2, GDs 1 and 90; group 3, GD 30; group 4, GDs 30 and 90; group 5, GD 90. Virus exposure was by either intrauterine (GD 1) or oronasal (GDs 30 and 90) inoculation. Gilts of group 6 were kept as nonexposed controls. Gilts were either necropsied on or about GD 111 (groups 1 to 5) or were allowed to farrow (group 6). The detection of PRRSV in serum of fetuses and piglets (within 12 hof birth) was considered evidence of transplacental infection. Transplacental infection and virus-induced death were and were not confirmed for groups 3, 4, and 5 and for groups 1, 2, and 6, respectively. Collectively, the results indicated that intrauterine exposure to PRRSV at GD 1 was without clinical effect (groups 1 and 2) and provided protection against subsequent exposure to the same strain of virus at GD 90 (group 2). The highest incidence of transplacental infection and fetal death followed a single exposure to PRRSV at GD 90 (group 5).     

Cloning and functional expression of a human liver organic cation transporter

OBJECTIVE: The triglyceride-lowering effects of omega-3 fats and HDL cholesterol-raising effects of exercise may be appropriate management for dyslipidemia in NIDDM. However, fish oil may impair glycemic control in NIDDM. The present study examined the effects of moderate aerobic exercise and the incorporation of fish into a low-fat (30% total energy) diet on serum lipids and glycemic control in dyslipidemic NIDDM patients. RESEARCH DESIGN AND METHODS: In a controlled, 8-week intervention, 55 sedentary NIDDM subjects with serum triglycerides > 1.8 mmol/l and/or HDL cholesterol < 1.0 mmol/l were randomly assigned to a low-fat diet (30% daily energy intake) with or without one fish meal daily (3.6 g omega-3/day) and further randomized to a moderate (55-65% VO2max) or light (heart rate < 100 bpm) exercise program. An oral glucose tolerance test (75 g), fasting serum glucose, insulin, lipids, and GHb were measured before and after intervention. Self-monitoring of blood glucose was performed throughout. RESULTS: In the 49 subjects who completed the study, moderate exercise improved aerobic fitness (VO2max) by 12% (from 1.87 to 2.07 l/min, P = 0.0001). Fish consumption reduced triglycerides (0.80 mmol/l, P = 0.03) and HDL3 cholesterol (0.05 mmol/l, P = 0.02) and increased HDL2 cholesterol (0.06 mmol/l, P = 0.01). After adjustment for age, sex, and changes in body weight, fish diets were associated with increases in GHb (0.50%, P = 0.05) and self-monitored glucose (0.57 mmol/l, P = 0.0002), which were prevented by moderate exercise. CONCLUSIONS: A reduced fat diet incorporating one daily fish meal reduces serum triglycerides and increases HDL2 cholesterol in dyslipidemic NIDDM patients. Associated deterioration in glycemic control can be prevented by a concomitant program of moderate exercise.     

A case of paraquat poisoning and subsequent fatality presenting to an emergency department

Paraquat (1,1'-dimethyl-4,4'-dipyridylium) is an herbicide associated with both accidental and intentional ingestion, leading to severe and often fatal toxicity. Prognosis is largely dependent on the amount of paraquat absorbed. Rapid identification of the symptoms of paraquat toxicity (burns or ulceration at the site of ingestion or injection, acute respiratory distress, and renal failure) can facilitate early treatment intervention to limit absorption. We report a case of a 71-year-old man with a suicidal ingestion of paraquat 2 days prior to presentation. Serum paraquat levels, time elapsed since ingestion, and clinical symptoms all indicated poor prognosis. The patient developed severe respiratory distress and progressive renal failure, and died 6 days after admission to the hospital.