Nucleotide sequence of the envelope protein genes of a highly virulent, neurotropic strain of Newcastle disease virus

The envelope glycoproteins of Newcastle disease virus (NDV), hemagglutinin-neuraminidase (HN) and fusion (F) proteins, play important roles in determining the host immune response and the virulence of that particular virus strain. The complete nucleotide sequence of the HN and F genes of a highly neurovirulent strain of NDV (Texas G. B., 1948) was determined in an effort to study the molecular basis of this strain's neurotropic properties. Comparison of the predicted amino acid sequences for the HN and F among the American NDV strains revealed that the Texas G. B. and Beaudette C envelope genes are closely related to each other and are less closely related to the avirulent B1 Hitchner strain. We have found 11 amino acid changes in the predicted HN protein between the Beaudette C and Texas G. B. strain but only 2 conservative amino acid changes (amino acids 11 and 197) in the F protein between these two strains. Although the virulence of NDV strains has been related to sequences at the cleavage site of F0, the property of neurovirulence cannot depend solely upon these sequences because there are no sequence differences between the Beaudette C and Texas G. B. strains. We suggest that the neurovirulence phenotype could be due to the molecular properties of the HN protein; however, we cannot exclude the possibility that the two conservative amino acid differences between the two F proteins could also play a role in determining the phenotypic differences between these two virus strains.

Rhinitis, pneumonia, and defective neutrophil function in the Doberman pinscher

Eight closely related Doberman Pinschers with chronic rhinitis and pneumonia had normal or increased numbers of structurally normal leukocytes. Serum concentrations of immunoglobulins and complement were above or within normal ranges. Lymphocyte transformation indices for 3 mitogens were normal in 7 of the 8 dogs; the remaining dog had low values for all mitogens. Neutrophils phagocytized bacteria normally, but had impaired bactericidal ability. The bactericidal defect may have been related to the inability of neutrophils to generate normal numbers of oxygen radicals after stimulation, as determined by decreased ability of neutrophils to reduce nitroblue tetrazolium and to produce superoxide following opsonized zymosan stimulation. These observations, plus finding chronic inflammatory disease in the lungs of one dog, indicated that the disease may have some similarity to chronic granulomatous disease or to complement receptor deficiency in man.

Proliposomes: a novel solution to an old problem

A procedure is described for the preparation of a dry, free-flowing granular product which, on addition of water, disperses/dissolves to form an isotonic liposomal suspension, suitable for administration either intravenously or by other routes. Various parameters have been investigated including the suitability of sorbitol and sodium chloride as carrier materials, the nature of the lipid(s) in the formulation, and the extent of lipid loading onto the carrier. These factors are shown to have a marked effect on both the dry product and the hydrated liposomes.

Fluoroscopic technique for double-contrast knee arthrography

The fluoroscopic double-contrast technique of arthrography of the knee is useful in documenting the extent of suspected injury to the knee. It is of particular value in demonstrating small and large lesions involving the menisci, cruciate ligaments, patellar cartilages, as well as the articular cartilages of the femoral condyles and tibial plateaus. This examination is instrumental in the diagnosis of the patient with an atypical history of injury and unusual physical findings. A simple restraint device allows the fluoroscopist complete control over the stress applied to the knee while positioning the patient for filming. Fluoroscopic spot radiographs of excellent contrast and sharp detail can be obtained of each of the various structures, applying the stress needed. When the radiologic technologist takes a little time to become more knowledgeable about the anatomy of the knee jount, and the rationale for the various views, the knee arthrographic examination is easily understood.

Neostigmine methylsulfate. Does it have a chronic effect as well as a transient one?

Three groups of 200-gm rats were injected subcutaneously with neostigmine methylsulfate (1 mg/kg/day) for 7, 30, and 100 days. Electrophysiological changes were assessed in vitro, using microelectrode techniques to examine diaphragm muscles of treated and untreated animals. Miniature end-plate potential (MEPP) amplitude decreased in neostigmine-treated preparations. Guanidine hydrochloride enhances transmitter release and increases MEPP frequency in control preparations. Neostigmine-treated animals examined between 6 to 72 hours after discontinuation of neostigmine therapy showed impaired response to the facilitating influence of guanidine. Recovery of response to guanidine was inversely related to length of treatment with neostigmine. Results of electron-microscopic examination of motor end-plates in treated animals revealed ultrastructural changes, including simplified end-plates, and, occasionally, multiple, separate, junctional regions. Therefore, the chronic administration of cholinesterase inhibitors in man may have a deleterious effect, as well as a transient beneficial one.