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Biomedical subjects

T K Miller

Publications and source records attributed to T K Miller.

21 records · Page 2Linked to original sources

A microprocessor-based instrument to measure pulmonary functions in critically-ill newborn infants.

Despite advances in the medical care of critically-ill newborn infants, chronic complications due to intense ventilatory support are common. Selection of ventilator settings is empirical, since measurement of pulmonary functions in newborn infants is not commonly performed. A microprocessor-based instrument was constructed to measure pulmonary function in critically-ill newborn infants with respiratory failure. Data collected fail to demonstrate any beneficial effect upon pulmonary mechanics with increasing amounts of continuous distending airway pressure, and in fact demonstrate an adverse effect upon the lung ventilation. These results demonstrate the need to measure pulmonary function to develop procedures to select optimum ventilator settings. A microprocessor-based system is suitable for such an application, and could be incorporated into future infant respiratory support equipment.

Diagnosis, Computer-Assisted↗

Neospora caninum infection in English Springer Spaniel littermates. Diagnostic evaluation and organism isolation.

Progressive paraparesis developed in four male English Springer Spaniel pups from a litter of five during the first 10 weeks of life. Two of the pups, which had the earliest onset of neurologic signs, were euthanatized without further workup. However, a detailed investigation was completed on the remaining two littermates at 12 weeks of age. Both pups had progressive paraparesis for 3 to 4 weeks before presentation, with one dog developing subsequent asymmetric pelvic limb extensor rigidity. Based on results from neurologic examination, cerebrospinal fluid (CSF) analysis, electrophysiology, and muscle/nerve biopsy, a presumptive diagnosis of protozoal polyradiculitis and polymyositis was made. Necropsy of the most severely affected pup confirmed the clinical diagnosis of inflammatory nerve root and muscle disease but no organisms were found. To increase the potential yield of organisms, the second pup was placed on immunosuppressive doses of corticosteroids and euthanatized 2 weeks later. Numerous organisms were found in lesions in muscle and the central nervous system. Organisms grew in tissue culture and were isolated from the peritoneal fluid of gerbils inoculated with infected tissue. Organisms were not isolated from inoculated mice, guinea pigs, rabbits, and hamsters. No parasites were seen in feces or tissues of three cats fed infected dog tissues. Serologic testing demonstrated a strong positive titer to Neospora caninum in both pups, and electron microscopy showed the characteristic morphology of this parasite.

Animals↗

Inhibition of the in vitro development of Eimeria tenella in chick kidney cells by immune chicken splenocytes.

An in vitro microbicidal assay was used to study the immune response of chickens to Eimeria tenella by measuring the effect of splenocytes from immunized chickens on intracellular development of E. tenella. Splenocytes were prepared from specific-pathogen-free chickens [strain P2a(B19B19) or N2a(B21B21)], immunized one, two, or three times with non-lethal doses of E. tenella. Twelve hours following infection of chick kidney cells (CKCs) with E. tenella sporozoites, splenocytes were added to infected CKCs for 4, 8, or 36 hours. Intracellular E. tenella development was allowed to continue until 72 hours after sporozoite infection, when intracellular development was quantitated by counting merzoites. Immune splenocytes significantly inhibited E. tenella intracellular development after one, two, or three immunizations. Significant inhibition occurred with 4, 8, or 36 hours of coculture and was no greater with longer co-culture times. Immune P2a splenocytes significantly reduced merozoite development in both syngeneic P2a and allogeneic N2a infected CKCs, whereas immune N2a splenocytes had little effect on E. tenella development in either N2a or P2a infected CKCs. These results suggest that immune splenocytes are induced and act relatively rapidly and are not apparently restricted by the major histocompatibility complex, consistent with natural killer cell activity.

Animals↗