Comparative severity of respiratory lesions of sialodacryoadenitis virus and Sendai virus infections in LEW and F344 rats

In several chronic diseases, lesions are more severe in LEW rats than in F344 rats. To determine whether or not acute viral diseases also are more severe in LEW rats than in F344 rats, we inoculated 6-7-week-old LEW and F344 rats with 10(7.2) cell culture infective units of sialodacryoadenitis virus or 10(4.7) infective units of Sendai virus. Twenty-four rats of each strain were given each virus. Lesions in nasal passages, tracheas, intrapulmonary airways, and pulmonary alveoli in 6 or 12 rats inoculated with each virus were assessed by scoring 5, 10, and 14 days after inoculation. Both viruses caused typical patchy necrotizing rhinitis, tracheitis, bronchitis, and bronchiolitis, with multifocal pneumonitis, in rats of both strains. Mean lesion indices for LEW rats given sialodacryoadenitis virus were significantly different from those for F344 rats for nasal passages on days 10 (0.999 vs. 0.680) and 14 (0.736 vs. 0.278), bronchi on day 5 (0.479 vs. 0.361), and alveoli on day 5 (0.677 vs. 0.275). Lesion indices for LEW rats given Sendai virus were significantly different from those for F344 rats for nasal passages on days 10 (1.000 vs. 0.611) and 14 (0.778 vs. 0.583); trachea on day 10 (0.625 vs. 0.028); bronchi on days 5 (0.476 vs. 0.331), 10 (0.123 vs. 0.013), and 14 (0.038 vs. 0); and alveoli on days 5 (0.413 vs. 0.114) and 10 (0.185 vs. 0.020). Thus, at the tested doses, both viruses caused more severe respiratory tract lesions in LEW rats than in F344 rats.     

Steam Surface Pasteurization of Beef Frankfurters

Meat and poultry products are sources of foodborne bacterial contamination. We used flash steam heating followed by evaporative cooling to quickly reduce bacterial contamination on the surface of beef frankfurters without degrading appearance. The rate of heat transfer was studied by measuring surface temperature in a pressure chamber during steam heating. Quality changes were determined by measuring color and weight as functions of steam temperature and treatment time. Efficacy of the process was verified by microbiological experiments using L. innocua. Treatment times of 30–40 set at 115–136°C gave a 4 log reduction in bacterial counts on the surface without severely affecting color or weight. After long-term storage at 6°C and at 19°C, levels of bacteria on inoculated frankfurters remained reduced and there was no difference between treated and untreated products in color or weight.     

Parvovirus B19 infection in AIDS patients

We report a 16-year-old boy, born to consanguineous parents, with mental retardation, gait disturbances and dysarthria; brain magnetic resonance showed features consistent with rhombencephalosynapsis. This condition is characterised by a hypoplastic single-lobed cerebellum. The interest of this case is the presence of common ancestors, pointing to an autosomal recessive inheritance of the malformation.     

A Narrowband Pulse-Echo Technique for In Vivo Ultrasonic Attenuation Estimation

The principles of a narrowband technique for pulse echo attenuation measurements are presented. Experiments are described which compare the attenuation in tissue-mimicking phantoms, measured by known methods, to the attenuation measured by the present technique. The effects of various experimental parameters on the results are investigated. The attenuation in spleens of canine models and in livers of human volunteers is presented.     

In Search of the "Ideal" Pear (pyrus spp.): Results of a Multidisciplinary Exploration

Preference mapping with 10 pears identified 3 segments among New Zealand consumers. While 1 segment preferred ripe European cultivars, another rejected only the seedling with strong off‐flavors. A 3rd segment combined the 2 former segments, but also rejected 2 hybrid samples. Survey responses to the question “To me, the ideal pear is ?” from a 2nd consumer sample confirmed the general preference for juicy and sweet pears, the key characteristics of ripeness. A separate appearance evaluation revealed 4 segments based on color and shape. Combining information from several sources resulted in suggestions for new breeding directions for pears, while highlighting the importance of appearance and the need for more extensive measurements.     

Effects of halothane anesthesia on the motility of the sphincter of Oddi and transsphincteric flow in Australian brush-tailed possums

We evaluated the effect of halothane anesthesia on the motility of the sphincter of Oddi and simultaneous transsphincteric flow in Australian Brush-tailed possums (Trichosurus vulpecula). Halothane levels in the range of 0.25 to 2% were administered and decreased transsphincteric flow in a dose-dependent manner. Sphincter of Oddi basal pressure was higher than normal, but not in a dose-dependent manner. Additionally, halothane anesthesia influenced the sphincter of Oddi motility by decreasing the motility index (mean amplitude multiplied by frequency of contractions). This decrease was dose dependent. These findings indicate that sphincter of Oddi basal pressure is a major component of sphincter of Oddi motility responsible for regulating transsphincteric flow in this species. For studies of the sphincter of Oddi motility in anesthetized Australian Brush-tailed possums, we recommend anesthetic induction with ketamine (50 mg/kg, i.m.) and the inspired halothane level should not exceed 0.75% during the study period, as the effects we have demonstrated were most evident at levels greater than 0.75%. If higher halothane levels are required to maintain satisfactory anesthesia, an alternative anesthetic agent should be considered.