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Biomedical subjects

J F Edwards

Publications and source records attributed to J F Edwards.

79 records · Page 5Linked to original sources

Lack of serologic evidence for an association between Cache Valley Virus infection and anencephaly and other neural tube defects in Texas.

We tested the hypothesis that Cache Valley Virus (CVV), an endemic North American bunyavirus, may be involved in the pathogenesis of human neural tube defects. This investigation followed a 1990 and 1991 south Texas outbreak of neural tube defects with a high prevalence of anencephaly and the demonstration in 1987 that in utero infection by CVV was the cause of outbreaks of central nervous system and musculoskeletal defects in North American ruminants. Sera from 74 women who gave birth to infants with neural tube defects in south Texas from 1993 through early 1995 were tested for CVV neutralizing antibody. All tested sera did not neutralize CVV. These data suggest that CVV is not involved in the induction of human neural tube defects during nonepidemic periods but do not preclude CVV involvement during epidemics. Other endemic bunyaviruses may still be involved in the pathogenesis of neural tube defects or other congenital central nervous system or musculoskeletal malformations.

Anencephaly↗

Food intolerance mimicking alimentary lymphosarcoma.

A cat with chronic diarrhea was diagnosed as having duodenal lymphosarcoma on two separate sets of endoscopic biopsies. Prednisolone failed to effect any clinical improvement. However, feeding the cat with a hypoallergenic diet resulted in long-term (i.e., six months) resolution of clinical signs. Most clinicians are familiar with the possibility of mistakenly diagnosing inflammatory bowel disease when the patient has lymphosarcoma; however, this case had the opposite problem: lymphosarcoma was diagnosed histologically on two separate occasions when inflammatory bowel disease was the problem.

Animals↗

Tracheal mucus transport rate and bacterial clearance in turkeys exposed by aerosol to La Sota strain of Newcastle disease virus.

Tracheal mucus transport rate (TMTR) and quantitative clearance of aerosolized Escherichia coli from the trachea, lung, and air sac were measured in healthy unanesthetized turkeys and in turkeys exposed by aerosol to a La Sota vaccine strain of Newcastle disease virus (NDV). The TMTR of uninfected turkeys was 42.4 +/- 14.7 cm/min. The TMTR of NDV-infected turkeys was depressed on days 3 through 7 postexposure (PE); depression was significant (P less than or equal to 0.05) on day 7 PE. Tracheal E. coli clearance in NDV-infected turkeys was reduced on days 4 through 9 PE, significantly so on day 5 PE (P less than or equal to 0.01). Depression of TMTR and tracheal E. coli clearance were associated histologically with replacement of normal pseudostratified columnar epithelium by 3 to 8 layers of immature nonciliated cells. E. coli clearance by the lung and air sac of NDV-infected turkeys was depressed on days 5 through 9 PE.

Air Sacs↗

Effects of Newcastle disease virus infection on the binding, phagocytic, and bactericidal activities of respiratory macrophages of the turkey.

Effects of Newcastle disease virus (NDV) infection on the binding, phagocytic, and bactericidal activities of turkey respiratory macrophages were studied. Respiratory macrophages of the turkey demonstrated the presence of immunoglobulin (Ig) G and complement receptors but lacked IgM receptors. Respiratory macrophages from NDV-infected turkeys showed little or no depression of binding of sheep erythrocyte-IgG complexes and sheep erythrocyte-IgM-complement complexes to their appropriate membrane receptors. In contrast, respiratory macrophages from NDV-infected turkeys showed significant (P less than or equal to 0.05) depression of phagocytosis of similar complexes. Bacterial killing by respiratory macrophages from NDV-infected turkeys was significantly (P less than or equal to 0.05) inhibited.

Animals↗

Clearance of bacteria in turkeys with Bordetella avium-induced tracheitis.

Quantitative clearance of aerosolized Escherichia coli from the trachea, lung, and air sacs was measured in turkeys infected with Bordetella avium. Clearance of E. coli in turkeys with B. avium-induced tracheitis was minimally affected early in infection. Sixteen to 23 days after infection with B. avium, sporadic, mild depressions in clearance of E. coli were observed in the tracheas, which had large areas of deciliated tracheal epithelium or replacement of normal epithelium by immature hyperplastic epithelium or metaplastic squamous epithelium. Clearance of E. coli from the lung and air sacs was minimally affected in turkeys infected with B. avium.

Animals↗

Tracheal mucus transport rate in normal turkeys and in turkeys infected with Bordetella avium (Alcaligenes faecalis).

Using the radiopharmaceutical 99mtechnetium-sulfur colloid, the tracheal mucus transport rate (TMTR) was measured in healthy unanesthetized turkeys and in turkeys infected with Bordetella avium. The TMTR of uninfected turkeys was 35.6 +/- 14.4 cm/min. The TMTR of B. avium-infected turkeys was normal on days 0 through 14 postexposure (PE), despite heavy bacterial colonization of the tracheal epithelium. On day 21 PE, the TMTR of B. avium-infected turkeys was significantly depressed (P less than or equal to 0.01) compared with that of control turkeys. Depressed transport was associated with extensive loss of ciliated epithelium from the tracheal mucosa and replacement of the normal mucosa by immature nonciliated epithelium or metaplastic squamous epithelium.

Alcaligenes↗

Induction, collection, and partial characterization of induced respiratory macrophages of the turkey.

Respiratory macrophages (RM) of the turkey were elicited with a 1:4 (v/v) suspension of incomplete Freund's adjuvant in sterile phosphate-buffered saline injected directly into the abdominal air sacs. RM were purified by passage through a Ficoll-Hypaque gradient resulting in 95.7 +/- 5.9% purity and 94.8 +/- 12.3% viability. On days 7 and 9 postinjection, adequate numbers (7.15 +/- 5.47 X 10(6) macrophages per turkey) of RM for in vitro experiments were obtained. RM of the turkey demonstrated the ability to adhere to glass, phagocytize Zymosan A, and kill Escherichia coli in vitro.

Animals↗