Detection of Infectious Pancreatic Necrosis Virus Using an Inhibition Enzyme-Linked Immunosorbent Assay

Abstract

An inhibition enzyme-linked immunosorbent assay was used to detect infectious pancreatic necrosis (IPN) virus. In this assay the presence of virus was determined by measuring the decrease in titer of a known antiserum after incubation with a sample suspected to contain virus. The titer of the antiserum was measured with an indirect enzyme-linked assay. Compared to the double antibody sandwich method this assay required fewer reagents (only one anti- IPN serum was required). This assay was also sensitive enough to detect virus at levels of 1×10² TCID₅₀/ml. of purified virus and was able to detect virus in samples obtained in the field.     

The Uncertain Significance of Low Vitamin D Levels in African Descent Populations: A Review of the Bone and Cardiometabolic Literature

Vitamin D levels in people of African descent are often described as inadequate or deficient. Whether low vitamin D levels in people of African descent lead to compromised bone or cardiometabolic health is unknown. Clarity on this issue is essential because if clinically significant vitamin D deficiency is present, vitamin D supplementation is necessary. However, if vitamin D is metabolically sufficient, vitamin D supplementation could be wasteful of scarce resources and even harmful. In this review vitamin D physiology is described with a focus on issues specific to populations of African descent such as the influence of melanin on endogenous vitamin D production and lactose intolerance on the willingness of people to ingest vitamin D fortified foods. Then data on the relationship of vitamin D to bone and cardiometabolic health in people of African descent are evaluated.     

Cued and spatial learning in the water maze: Equivalent learning in male and female mice

Mammals navigate a complex environment using a variety of strategies, which can operate in parallel and even compete with one another. We have recently described a variant water maze task in which two of these strategies, hippocampus-dependent spatial learning and striatum-dependent cued learning, can be dissociated. Male rodents perform better at some spatial learning tasks, while female rodents more readily learn certain striatum-dependent behavioral strategies. We therefore predicted that sex would differentially influence spatial and cued learning in the water maze. We trained adult male and female C57Bl/6 mice for 7 days in the two-cue variant of the water maze, with probe trials on days 5 and 7. In two independent experiments, males and females performed similarly, with both groups showing good spatial learning after 5 and 7 days of training, and both groups showing trend-level cued learning after 5 days and robust learning after 7. Therefore, contrary to our hypothesis, sex does not significantly affect cued or spatial learning in this task.     

Dietary supplementation with marine omega-3 fatty acids improve systemic large artery endothelial function in subjects with hypercholesterolemia

OBJECTIVE: This work was undertaken to determine whether dietary supplementation with marine omega-3 fatty acids improve systemic large artery endothelial function in subjects with hypercholesterolemia. BACKGROUND: Marine omega-3 fatty acids improve vascular function, but the underlying mechanism(s) are unclear. We studied the effects of marine omega-3 fatty acids on large artery endothelial function in subjects with hypercholesterolemia. METHODS: Hypercholesterolemic subjects with no other known cause for endothelial dysfunction were recruited to a prospective, placebo-controlled, randomized, double-blind, parallel-group study. Treatment with omega-3 fatty acids at a dose of 4 g/day (n = 15/group) was compared with placebo, at the beginning (day 0) and end (day 120) of a four-month treatment period. Endothelial function was assessed pre- and posttreatment by noninvasive ultrasonic vessel wall tracking of brachial artery flow-mediated dilation (FMD). RESULTS: Treatment with marine omega-3 fatty acids resulted in a significant improvement in FMD (0.05 +/- 0.12 to 0.12 +/- 0.07 mm, p < 0.05) and a significant reduction in triglycerides (2.07 +/- 1.13 to 1.73 +/- 0.95 mmol/liter, p < 0.05), whereas treatment with placebo resulted in no change in FMD (0.03 +/- 0.10 to 0.04 +/- 0.10 mm) or triglycerides (2.29 +/- 2.09 to 2.05 +/- 1.36 mmol/liter) (both p < 0.05 treated compared with control). Responses to sublingual glyceryl trinitrate were unchanged. CONCLUSIONS: Marine omega-3 fatty acids improve large artery endothelium-dependent dilation in subjects with hypercholesterolemia without affecting endothelium-independent dilation.     

The effect of respiratory viral infections on patients with cystic fibrosis

We examined, in a 2-year prospective study, the frequency of respiratory viral infections in 19 school-age patients with cystic fibrosis and their unaffected siblings. At 2-month intervals throughout the study period, pulmonary function tests, oropharyngeal cultures, and serologic tests for respiratory viruses were performed in all subjects. Quantitative sputum cultures for bacteria were performed in subjects with cystic fibrosis. The same laboratory specimens were also collected at the time of all acute respiratory illnesses. Over the 2-year period, 398 viral cultures and serum samples were collected, 210 from patients with cystic fibrosis and 188 from their siblings. The frequency of culture-documented and seropositive viral infections was not significantly different between patients with cystic fibrosis and their siblings. The patients with the highest frequency of viral infection were younger and had the lowest rate of decline in lung function and severity score. We conclude that school-age patients with cystic fibrosis are no more susceptible to viral infections than their unaffected siblings. We were unable to demonstrate any significant adverse effect of respiratory viral infections on pulmonary function in 19 patients with cystic fibrosis aged 5 to 21 years.     

Haemophilus B polysaccharide vaccine. Antibody kinetics in 17- to 71-month-old children

The antibody response to polysaccharide vaccines is well known to be age variable, with younger infants or children responding less dependably and with lower antibody levels. The fate of these induced antibodies over time is less well understood. We studied the antibody kinetics of beta-Capsa 1, a Haemophilus B polysaccharide vaccine, in 185 children aged 17 to 71 months. Ninety percent of the children vaccinated at age 2 years or older achieved reportedly immune serum antibody levels three weeks after vaccination; 45% vaccinated at age 18 months achieved such levels. In six months, the antibody levels fell significantly in all children. In those vaccinated at age 18 months, the levels six months after vaccination were not significantly different from those prior to vaccination. Our study raises the possibility that antibody kinetics may be as critical a consideration as immediate antibody response in deciding the proper clinical use of a polysaccharide-based vaccine.     

Healthcare Charges and Use in Commercially Insured Children Enrolled in Managed Care Health Plans in Washington State

Objective: To determine the relative importance of enrollee, physician, medical group, and healthcare plan characteristics as determinants of healthcare use and expenditures in commercially insured children <18 years of age enrolled in managed care health plans. We focused on the effects of age and benefit level, the two most important predictors of cost and utilization in our study of adults. Methods: This study included 67,432 commercially insured children who were between 1 and 18 years of age, and were cared for by 790 primary care physicians, who practiced in 60 medical care groups in Washington State. Plan enrollment and utilization data for 1994 were linked to a survey of medical care groups contracting with three managed care health plans. Benefit level for each enrollee was defined as low, medium, or high and was based on cost sharing by the health plan for hospitalization, outpatient care, and emergency department services. The three outcome measures included estimated total per member per year charges, number of ambulatory visits, and hospital days. Results: In multivariate analysis, enrollee age was the most important determinant of total charges, with younger children incurring higher charges and utilization. For children 5 years and younger, mean total per member per year charges were $617 in the low-benefit category and $878 in the high category (p < .0001). These differences were less apparent for children 6–12 years ($355 versus $420, p = .012), and were not statistically significant for children 13 years and older ($503 versus $552, p = .14). The annual number of visits increased with benefit level for children of all ages. Conclusions: Enrollee age and benefit level were the most important determinants of healthcare use and expenditures in children enrolled in managed care health plans.     

The clinical diagnosis of asphyxia responsible for brain damage in the human fetus.

OBJECTIVE: Our objective was to review the clinical findings in infants who died in the perinatal period with brain damage attributable to asphyxia. STUDY DESIGN: The neuropathologic findings in 208 perinatal deaths have been reviewed. Thirty cases (22 fetal, eight newborn) had evidence of white matter or neuronal necrosis due to asphyxia. The clinical course of the pregnancy in 22 cases with brain damage attributable to fetal asphyxia were examined. RESULTS: The diagnosis of asphyxia was confounded by several factors: (1) asphyxia may occur at any time in the last half of pregnancy, (2) 50% of the antepartum asphyxia occurred when the pregnancy had no risk factors, (3) periodic fetal assessment in the complicated preterm pregnancies failed to identify the asphyxial episodes in the remaining cases of antepartum asphyxia, and (4) indicators of fetal asphyxia in the cases of intrapartum fetal asphyxia were obtained after the central nervous system injury had occurred. CONCLUSION: These findings highlight the difficulty in the diagnosis of fetal asphyxia at a stage that could permit intervention to prevent brain damage.