Polymerase chain reaction amplification of wildebeest-associated and cervine-derived malignant catarrhal fever virus DNA

A polymerase chain reaction (PCR) assay was developed for the detection of alcelaphine herpesvirus 1 (AHV1), a causative agent of malignant catarrhal fever (MCF) of ruminants. A pair of 20-base primers was constructed based on the published nucleotide sequence of gene A of the WC11 isolate of AHV1 and was used to amplify a DNA fragment of 413 base pairs. The optimised PCR assay was highly sensitive, i.e. it detected 10 fg of genomic DNA of AHV1 (WC11 isolate). The amplified fragment was shown to be specific for AHV1 DNA by (i) cleavage with XbaI which yielded 2 subfragments of approximately 140 and 280 base pairs and (ii) chemiluminescence Southern blot hybridisation with a digoxigenin-labelled 25-base internal probe. The PCR assay also amplified AHV1 gene sequences in tissue samples from deer and rabbits experimentally infected with materials derived from deer with clinical sheep-associated MCF.

Pulmonary edema complicating upper airway obstruction in infants and children

The association of pulmonary edema with upper airway obstruction occurs in three clinical settings: acute and chronic upper airway obstruction and immediately after the relief of acute upper airway obstruction. Iatrogenic causes, such as adenotonsillectomy and tracheal intubation, were the most frequently encountered in the authors' series of 21 pediatric patients with such an association. The pathogenesis of this kind of pulmonary edema is multifactorial. The application of moderate continuous positive airway pressure in conjunction with the administration of diuretics rapidly clears pulmonary edema in all three clinical settings, usually within 24 hours, and can probably prevent pulmonary edema immediately after acute obstruction is relieved.

A computerized test battery for the assessment of cardiovascular reactivity

Recent evidence has suggested a possible relationship between the tendency to exhibit excessive cardiovascular reactions during psychological challenge and the risk of cardiovascular disease. Valid techniques for reliably assessing such reactions are, however, minimally available. A test battery for the assessment of cardiovascular reactivity to experimental challenge is currently being developed at the University of Pittsburgh in conjunction with the University of Miami and Duke University. An IBM-AT compatible microcomputer is being used for the concurrent collection of physiological data and presentation of the laboratory stressors. Digitized cardiovascular data being collected include EKG, Impedance Cardiogram (ICG), phonocardiogram, and a peripheral pulse wave measure. Blood pressure readings are also being collected and stored on disk. The computer presents three challenging video games, each designed to elicit cardiovascular reactions. Processing programs are being used and developed for the standardized scoring of the digitized signals. To assist in epidemiological research a mobile testing unit has been assembled for the easy administration of the test battery in varying geographical locations. The test battery being developed will increase the feasibility of epidemiological and clinical assessment of stress-induced cardiovascular responses which may substantiate a link between reactivity and cardiovascular disease.

Increased renal parenchymal echogenicity: causes in pediatric patients

The authors discuss some of the diseases that cause increased echogenicity of the renal parenchyma on sonograms in children. The illustrated cases include patients with more common diseases, such as nephrotic syndrome and glomerulonephritis, and those with rarer diseases, such as oculocerebrorenal syndrome. Hyperechogenicity is a nonspecific finding but a significant one in that it suggests the presence of renal abnormalities. When it is demonstrated, further investigation is usually warranted.

Effectiveness of abdominal radiographs in visualizing chewable iron supplements following overdose

The purpose of this study was to determine the clinical effectiveness of visualizing chewable and nonchewable iron supplements remaining in the gastrointestinal tract following an overdose. A 5-year retrospective review of 93 pediatric patients who had ingested potentially toxic amounts of an iron supplement found that 58% had abdominal radiographs taken. Fifty-five percent of these patients had ingested chewable multiple vitamins with iron and 40% had ingested nonchewable tablets. After radiographic review, radiopaque densities could be marginally visualized in only one case of ingestion of a chewable iron supplement. The mean serum iron level of patients who had ingested a chewable form of iron was 270 micrograms/dL. An in vitro study was performed to determine the radiopacity of various chewable multiple vitamins with iron. It was concluded that although chewable multiple vitamins with iron are radiopaque in vitro, clinical radiographic visualization is unlikely.

Occult fractures in preschool children

Five hundred consecutive radiographic examinations of acutely limping infants and toddlers were analyzed retrospectively. One hundred of the 500 (20%) had a fracture as the underlying etiology. Although the most common sites of involvement were the tibia/fibula (56 cases) and femur (30 cases), fractures in the pelvis and feet, notably the metatarsals (11 cases), also were seen. We therefore recommend obtaining radiographs of the pelvis and both lower extremities including the feet, when occult trauma is suspected and the exact area of injury cannot be pinpointed clinically.

Acute chondrolysis complicating Legg-Calvé-Perthes disease

Of 270 children with Legg-Calvé-Perthes (LCP) disease, roentgenographic evidence of chondrolysis was noted in 12 (4.5%) within one year after diagnosis and appropriate management. Only in six hips of these 12 patients did the retrospective clinical, histological, and orthopedic findings fulfill the diagnostic requirements for chondrolysis. Sequential roentgenographic findings included initial periarticular osteoporosis and subchondral cortical irregularities, subsequent narrowing of the joint space, premature fusion of the growth plate, and eventual development of degenerative arthritis. The early roentgenographic recognition of chondrolysis is emphasized because it has an untoward effect on the prognosis of LCP and should therefore prompt a different orthopedic approach.