PubMed Health⌕ Search

Biomedical subjects

N F Cheville

Publications and source records attributed to N F Cheville.

At least 91 records · Page 5Linked to original sources
PubMed1985

Monocytic origin and postnatal mitosis of intravascular macrophages in the porcine lung.

Ultrastructural studies of near-term to 2-month-old pigs were done to document characteristics and developmental changes of intravascular macrophages in pulmonary capillaries. Evidence is presented that blood monocytes colonize the porcine lung perinatally, replicate within capillaries postnatally, and attach to endothelium by intercellular junctions during differentiation. Major ultrastructural features of differentiated intravascular macrophages are adhesion to capillary endothelium, pseudopods, phagosomes, and tubular structures of micropinocytosis vermiformis. Ultrastructure indicates that intravascular macrophages are cells of the mononuclear phagocyte system involved in several functions (eg, blood cell sequestration) that are usually attributed to hepatolineal macrophages. In newborn and 3-day-old pigs, the majority of cells closely apposed to endothelium consisted of few differentiated monocytes, but in 7-day-old and older animals, most cells that were joined to endothelium had characteristics of differentiated intravascular macrophages.

Animals↗
PubMed1985

Pathology of cloacal bursae of gnotobiotic turkeys orally inoculated with Escherichia coli.

Cloacal bursae from three-week-old gnotobiotic turkeys were examined by light and electron microscopy and bacteriologic techniques at 1, 2, 5, 8, 12, and 16 days after oral inoculation of highly virulent (group 1) and weakly virulent (group 2) Escherichia coli. In both groups a significant decrease in follicular volume and increase in interstitial volume were associated with infection. Follicular cortical, follicular medullary and total follicular transectional areas increased with time in inoculated and control turkeys. In group 1, granulocytic inflammation developed in bursae on day 1 and diminished by day 8 after inoculation. Microabscesses were present on days 5 and 8 after inoculation in less than 1% of follicles. Bacteria were seen in few follicular medullae on days 5 and 8 after inoculation; bacteremia was detected on days 1, 2, and 5 after inoculation. In group 2, pyogranulomatous bursitis was first seen at five days after inoculation and became progressively more severe with time. Follicular alterations in group 2 included abscessation, lymphocyte necrosis, reticuloepithelial hyperplasia and perifollicular fibroplasia. Ultrastructurally, follicular pads had degenerate and necrotic epithelial cells, intercellular edema, and cystic spaces that contained acidic mucosubstances and laminar deposits of calcium salts. Bacteria were seen within necrotic centers of follicular abscesses, in phagosomes of macrophages and multinucleate giant cells and within extracellular spaces of follicular pads and follicular medullae from day 5 to day 16 after inoculation; no bacteremia was detected. We conclude that E. coli passes through the bursal follicle-associated epithelium and replicates within follicular medullae, that extensive follicular necrosis is associated with persistence of E. coli in follicular medullae, and that E. coli of low virulence may cause severe pyogranulomatous bursitis in young turkeys without causing the respiratory or systemic diseases which are commonly associated with organisms of high virulence.

Animals↗
PubMed1984

The neonatal porcine lung: ultrastructural morphology and postnatal development of the terminal airways and alveolar region.

Morphology and postnatal development of the porcine lung are described in animals ranging in age from newborn through 60 days. Standardized fixation was accomplished by intratracheal instillation of glutaraldehyde under constant pressure. Light microscopic, scanning, and transmission electron microscopic investigations revealed that the porcine lung follows the common architecture of mammalian lungs, but has certain peculiarities as well: intravascular macrophages, ultrastructurally similar to Kupffer cells, are attached to endothelial cells in pulmonary capillaries and are involved in erythrophagocytosis during the first postnatal weeks. Type II pneumocytes of newborn pigs exhibit signs of cell activation, mainly complex nuclear bodies in the cell nuclei. At the same time high levels of 17-hydroxycorticosteroids are observed in the newborn blood plasma. Terminal airways of the porcine lung are nonalveolarized and are, therefore, of purely conductive function. At birth the porcine lung exhibits a high degree of maturity, and thick-walled primary saccules, as described in newborn rodents, are not seen. Septa appear straight and smooth, owing to rare ramification. Septal buds are discernible, and two capillary networks visible on both sides of septal cross sections are seen. Further subdivision of the airspaces occurs in the first two postnatal weeks. Precociousness and fast postnatal growth of the porcine species are assumed to be the reason of this advanced degree of lung maturity at birth and the following rapid pulmonary development.

Animals↗
PubMed1984

Pathogenicity of equine herpesvirus 1 subtype 2 for foals and adult pony mares.

Three pony mares and 4 pony foals were inoculated with a subtype 2 strain of equine herpesvirus 1. Foals had periods of fever 12 h and 2.5 days after inoculation and leukopenia, involving both neutrophils and lymphocytes, followed by leukocytosis. Mares had transient fever and leukopenia 24 hours after inoculation that were less severe than in foals. An increase in circulating virus-neutralizing antibody was seen in 2 of 3 inoculated mares, but not in foals. Attempts to isolate virus from blood were unsuccessful. These studies show that equine herpesvirus 1 subtype 2 is a mild pathogen for ponies and infection may result in inapparent clinical disease.

Animals↗
PubMed1984

Pathology of maternal genital tract, placenta, and fetus in equine viral arteritis.

Six pregnant mares were given equine viral arteritis virus intravenously. Tissues from genital tracts, placentae, and fetuses were examined by light and electron microscopy to study the mechanism of abortion. Four mares which died with acute disease had diffuse vacuolation of endometrial epithelium and systemic necrotizing vasculitis. Two of these mares had dead fetuses and two had live fetuses; virus was isolated from tissues of one live fetus. Placentae of mares dying from acute disease did not have lesions attributable to infection; virus was isolated from two of these placentae. One of the two mares which recovered from clinical disease aborted a dead fetus eight days after inoculation. The mare had severe necrotizing myometritis and virus was isolated from maternal ovaries and from fetal tissues. The fetus did not have lesions attributable to arteritis virus. These results suggest that although fetal death may occur in utero during acute equine viral arteritis, abortion probably is due to lesions in the uterus of the mare.

Abortion, Spontaneous↗
PubMed1984

Ultrastructure of Prototheca zopfii in bovine granulomatous mastitis.

Mammary glands from cows with protothecal mastitis were examined by light and electron microscopy at 6, 13, 20, and greater than 180 days after infection. With increasing time, there were increases in severity of granulomatous inflammation, number of endospores and sporangia, and ratio of degenerate to intact algae. Algae were found in macrophages but were not seen in neutrophils, epithelial cells, or myoepithelial cells. Macrophages containing algae were markedly enlarged, chiefly from reduplication of the Golgi complex and its associated vesicles. Intracellular algae were degenerate and consisted of intact cell wall profiles which contained membrane fragments but lacked nuclei and cytoplasmic organelles. Degenerate algae in vitro had thin cell walls and did not undergo internal lysis. Cell wall material of intracellular algae stained as an acidic, nonsulfated, carboxylated glycoprotein. These findings suggest that intracellular Prototheca zopfii degenerate by progressive lysis of internal organelles with persistence of cell wall glycans and that development of aberrant cell wall forms occurs as a defective response by host macrophages.

Animals↗
PubMed1984

Cellular lesions in intestinal mucosa of gnotobiotic calves experimentally infected with a new unclassified bovine virus (Breda virus).

Four gnotobiotic calves were inoculated intranasally with Breda virus within two hours after cesarean section. Three calves developed diarrhea between 48 and 60 hours after inoculation; one calf was killed at 36 hours. Consistent microscopic findings in the intestinal mucosae of calves with diarrhea were cytopathologic changes in enterocytes of the lower small intestine, large intestine, and dome epithelial cells and an acute inflammatory response with cellular infiltration and subtle changes in capillaries. Virions with average dimensions of 35 x 80 nm were seen in rounded cells that had severe cell swelling, dilatation of the cytocavitary network, and hydropic degeneration. Virions were most often in multiple, large autophagolysosomes. There was a good correlation in detection of virus in cells with electron microscopy and indirect immunofluorescence. No lesions were detectable in two control calves killed five days after inoculation.

Animals↗
PubMed1984

Functional and ultrastructural changes in neutrophils from mares and foals experimentally inoculated with a respiratory tract strain of equine herpesvirus-1.

Neutrophils isolated from venous blood of adult and foal ponies inoculated with equine herpesvirus-1 were evaluated by in vitro function tests and by electron microscopy. Foals had fever and severe neutropenia 24 hours after inoculation; increased neutrophil random migration under agarose and decreased antibody-dependent cell-mediated cytotoxicity were significant at 24 hours, but values had returned to preinoculation levels by 72 hours. Mares had fever and leukopenia of less severity, increases in neutrophil migration, and longer persistence of primary granule release than were seen in foals. Reduced migration and degranulation, and a decrease in antibody-dependent cell-mediated cytotoxicity seen with neutrophils from foals, as compared with mares, may relate to the high susceptibility of foals to equine herpesvirus-1 infection.

Animals↗
PubMed1984

Tracheal lesions in young turkeys infected with Bordetella avium.

Forty-six turkeys were inoculated intranasally with Bordetella avium at 3 days of age. Inoculated and non-inoculated turkeys (n = 72) were necropsied sequentially from post-exposure days (PED) 3 to 53. Tracheal lesions were studied histologically. Mild fibrinopurulent tracheitis, associated with bacterial colonization of ciliated epithelium, was seen at PED 7 to 10. At PED 14 and 21, there were numerous bacterial colonies, loss of ciliated cells, epithelial hyperplasia, depletion of mucus, and diffuse infiltration of lymphocytes and macrophages. At PED 28, the mucosa and tracheal rings were severely distorted. The mucosal epithelium, composed of immature epithelial cells and nononuclear leukocytes, had formed prominent longitudinal folds. Mucous glands were cystic and lined by low cuboidal epithelium. At PED 42 and 53, tracheas appeared normal, except for residual distortion of tracheal rings and shortened luminal epithelium.

Agglutination Tests↗
PubMed1984

Pathogenesis of Staphylococcus aureus mastitis: bacteriologic, histologic, and ultrastructural pathologic findings.

Three lactating cows were experimentally infected with Staphylococcus aureus ATCC 29740 (Newbould 305 strain). Cows were euthanatized 2 to 216 hours after inoculation. Bacteriologic and microscopic examinations showed that S aureus attached to epithelial cells of the mammary gland in vivo. The histopathologic changes observed were progressive swelling, vacuolar degeneration of epithelial layers, and multiple foci of epithelial erosions and ulcers throughout the ductal system. The cellular response of the infected glands was demonstrated by a rapid increase in the number of somatic cells in the secretion and by accumulation of neutrophils below, within, and on the epithelium of the teat and lactiferous sinuses. The inflammatory response did not prevent infection nor subsequent pathologic changes in the inoculated glands.

Animals↗
PubMed1984

Natural and experimental bovine intramammary infection with Prototheca zopfii.

A naturally occurring case of chronic mastitis caused by Prototheca zopfii was detected in a dairy cow. The cow was observed for 12 weeks, and milk samples were cultured each week. Milk production was decreased, and high numbers (greater than 10(3)/ml) of the organism were detected in the milk. Six glands of 2 cows were inoculated with small numbers of P zopfii. All 3 cows were euthanatized, and at postmortem, a progressive pyogranulomatous inflammation was observed in all infected mammary glands. The organism was recovered from tissue and secretions from all inoculated glands and from lymph nodes draining these glands but not from other tissues.

Animals↗
PubMed1984

Functional and ultrastructural evaluation of neutrophils from foals and lactating and nonlactating mares.

Neutrophils from 4 pony foals, 3 lactating pony mares, and 3 nonlactating mares were evaluated ultrastructurally and by in vitro function tests. Neutrophils from foals had significantly (P = 0.05) less random migration than neutrophils from mares; values in tests for iodination and Staphylococcus aureus ingestion were also lower with foal neutrophils. Neutrophils from lactating mares had lower responses to iodination, antibody-dependent cell-mediated cytotoxicity, and random migration tests than did neutrophils from nonlactating mares. Ultrastructurally, granule concentration did not differ significantly among groups. A slight decrease in primary granules and a corresponding increase in granules with a flocculent matrix indicates partial spontaneous neutrophil degranulation in foals and lactating mares.

Animals↗
PubMed1981

Pathology of experimental vitamin D deficiency in chickens and effects of treatment with vitamin D metabolites.

Structural changes in bone, parathyroid, and ultimobranchial body were examined in three groups of chicks fed a vitamin D-deficient diet; one group was treated with vitamin D3 and another with 1,25(OH)2D3. Diets were fed from day of hatching until 5 weeks old, when deficient chicks were near death due to hypocalcemic tetany, loss of fat and muscle, and marked bone deformities. In deficient chicks, parathyroid mass increased linearly to 7.5 times normal at 5 weeks. Parathyroid cells were irregular and vacuolated, with few granules. 1,25(OH)2D3 had normal parathyroids until the fifth week, when parathyroid mass increased greatly. There were few differences in length of growth cartilage, but marked changes in length of metaphyses. Deficient chicks had metaphyses nearly five times longer than vitamin D3-treated chicks. Metaphyses in chicks given 1,25(OH)2D3 were twice as long as those of vitamin D-treated chicks at 5 weeks. Both osteoblasts and osteoclasts were more numerous in deficient chicks. These studies suggest that vitamin D3 is more effective than 1,25(OH)2D3 in preventing parathyroid and bone lesions of vitamin D deficiency.

Animals↗
PubMed1981

Lesions in the small intestine of newborn pigs inoculated with porcine, feline, and canine coronaviruses.

The infectivity and pathogenicity to newborn pigs of antigenically related coronaviruses from pigs (transmissible gastroenteritis virus; TGEV), cats (feline infectious peritonitis virus; FIPV), and dogs (canine gastroenteritis virus; CGEV) were studied by light, scanning electron, and immunofluorescence microscopy. Hysterectomy-derived, 12-hour-old pigs were orally given tissue culture or frozen preparations of 6 coronavirus strains (3 porcine, 2 feline, and 1 canine). The pigs were killed at regular intervals between 24 and 144 hours after exposure. Virulent TGEV and virulent FIPV produced necrosis of villous epithelium, resulting in villous atrophy in the jejunum and the ileum. Similar, but less extensive and severe lesions, were produced by the 4 other viruses. Coronaviral antigens were identified by immunofluorescence in villous epithelial cells of pigs that had been inoculated with virulent TGEV, attenuated TGEV, virulent FIPV, and tissue culture-adapted FIPV. In contrast, coronaviral antigens were not induced by the small plaque variant TGEV and virulent CGEV in the villous epithelium, but rather in cells of the lamina propria and crypt epithelium.

Animals↗
PubMed1981

Interaction of blood-borne Escherichia coli with phagocytes of spleen and liver in turkeys.

The response of splenic and hepatic macrophages to blood-borne virulent and avirulent Escherichia coli was studied in 3-week-old turkeys. Bacterial titers in blood, spleen, and liver were determined for 20 minutes after IV injection of E coli. Spleen and liver were examined by light and electron microscopy. Blood titers of avirulent E coli were reduced to 1/3,000 of their original level in 20 minutes, whereas titers of virulent E coli were only slightly reduced. The E coli localized in macrophages of hepatic sinusoids and splenic reticular sheaths (ellipsoids). In liver, phagocytosis was more efficient for avirulent E coli than for virulent E coli. In splenic macrophages, phagosomal membranes were separated from ingested avirulent E coli by a prominent space, whereas phagosomal membranes surrounding virulent E coli were wavy and closely apposed to the bacterial surface. The appearance of phagosomes may reflect the capacity of splenic macrophages to kill intracellular E coli. Cultural and histopathologic results indicated that virulent E coli resisted trapping and killing by macrophages of spleen and liver.

Animals↗
PubMed1980

Ultrastructure of renal lesions in pigs with acute leptospirosis caused by Leptospira pomona.

Twelve 4-day old, pathogen-free pigs were inoculated intraperitoneally with virulent L. pomona. Two pigs each were killed 1, 2, 3, 5, 7, and 14 days after inoculation and their kidneys examined by light and electron microscopy. Three to 5 days after inoculation there was hyperemia, edema and swelling of tubular epithelium; leptospires were detected intravascularly, in interstitium and embedded within basement membranes. At day 7, leptospires were at basal surfaces of proximal tubules and in phagosomes in tubular epithelium. Perivascular aggregates of monocytes and macrophages were prominent. At day 14, intersitial cells were chiefly plasmacytes and lymphocytes. Leptospires were only on tubular epithelial cell surface microvilli. In another experiment, all pigs receiving low-virulent strains had leptospires in the renal interstitium at 7 days after inoculation but had none at 14 days. All low-virulent strains produced degenerative changes and lymphocyte-plasmacytic infiltration. These studies indicate that non of the low-virulent isolates were acceptable for use in vaccines. Fialure of leptospires to remain attached to microvilli of proximal tubules in late stages of acute infection may be related to differences in virulence of various isolates.

Anemia↗