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Biomedical subjects

D L Harris

Publications and source records attributed to D L Harris.

At least 109 records · Page 6Linked to original sources
PubMed1982

The evaluation of lung immunity in chimpanzees.

The development of immunity in the chimpanzee was evaluated at 5 through 14 days after the deposition of a particulate antigen into a single lung lobe. An increased number of IgA, IgM, and IgG antibody-forming cells were found in the immunized lung lobes and in the blood. Few antibody-forming cells were found in the control lung lobes. The results from the chimpanzees were qualitatively the same as those from previous studies in which single lung lobes of dogs were immunized. However, a higher number of IgA antibody-forming cells was observed in the lavage fluid from chimpanzees than in that from dogs.

Animals↗
PubMed1982

Recruitment of antibody-forming cells in the lung after local immunization is nonspecific.

The deposition of particulate antigen into the dog lung induces a large accumulation of antigen-specific-forming cells in immunized lung lobes. The results of our previous studies with dogs indicate that these cells are recruited to the immunized lung lobes from the blood. The present study was designed to determine if the recruitment of immune cells to the lung is antigen-specific, or if changes occur in the lung after immunization that allow immune cells to enter the lung nonspecifically. Dogs were immunized in the left and right cardiac lung lobes with antigenically different particulate antigens. The number of lymphoid cells producing antibody to each antigen and the concentrations of antigen-specific antibody were measured in the immunized lung lobes and in a control lung lobe at 5 through 14 days after immunization. Similar numbers of antibody-forming cells and concentrations of antibody to both antigens were found in each immunized lung lobe, regardless of which antigen was used for immunization. These results indicate that antigen exposure alters the lung to allow a nonspecific recruitment of immune cells from the blood into the immunized lung lobes, regardless of antigen specificity. These data also provide further evidence that the antibody-forming cells found in the lung lavage fluid after localized immunization are produced in the thoracic lymph nodes or other systemic lymphoid tissues, rather than locally in lymphoid tissues in the deep lung.

Animals↗
PubMed1982

Porcine proliferative enteritis: experimentally induced disease in cesarean-derived colostrum-deprived pigs.

The hypotheses that porcine proliferative enteritis is an infectious disease and that Campylobacter sputorum subsp mucosalis (CSM) is involved in the development of this disease were experimentally tested. Three experiments were conducted with 10-week-old, cesarean-derived colostrum-deprived pigs. Of 22 pigs given homogenized mucosal scrapings (crude inocula) intragastrically, 15 had gross and/or microscopic lesions of proliferative enteritis. Of 10 pigs inoculated with cultures of both CSM and Salmonella cholerae-suis, 2 had evidence of proliferative enteritis. The 4 pigs treated with S cholerae suis only had diffuse fibrinous gastroenteritis without evidence of mucosal proliferation. Proliferative enteritis was produced in 1 of 5 pigs inoculated with pure cultures of CSM. Proliferative lesions in the intestine were characterized by the proliferation of immature crypt epithelial cells. Affected cells contained variable numbers of curved, intracytoplasmic Campylobacter sp organisms. The CSM organism was isolated from the intestinal mucosa of 8 pigs treated with either crude inocula or cultures of CSM.

Animals↗
PubMed1981

Accidental intrapulmonary Clinifeed.

A case is described in which a narrow bone nasogastric tube was passed into the bronchial tree and feeding with half-strength Clinifeed commenced before the malposition was recognised. The management of the resulting acute respiratory failure is discussed, and the successful outcome attributed to the bland nature of the Clinifeed. The need for radiological confirmation of the position of narrow bone nasogastric tubes before feeding is emphasised.

Acute Disease↗
PubMed1981

Bacteriologic study of sow agalactia.

Necropsy of 13 agalactic and 11 normally lactating sows at 1 to 2 days after parturition revealed that 7 of the agalactic and 4 of the clinically normal sows had lesions of mastitis. Escherichia coli, Streptococcus equisimilis, and Staphylococcus epidermidis were the predominant organisms isolated. The organisms were isolated as pure and as mixed cultures and all 3 were isolated from normal appearing, as well as mastitic, glands. Pure culture isolation of E. coli (44 gland segments) was significantly associated with microscopic lesions of mastitis, regardless of the number of colonies isolated, whereas pure culture isolation of Streptococcus equisimilis or S epidermidis in low to moderate numbers was not. Isolation of large numbers of beta-hemolytic streptococci (2 gland segments) or of S epidermidis (6 gland segments) was associated with microscopic evidence of mastitis. Cultural examination of uterus and cervix revealed 5 isolates of strict anaerobic bacteria, all different species, from 4 of the 24 sows. Culture of 2 mammary glands from each sow revealed no strict anaerobes. Phase-contrast microscopic examination of specimens from mammary glands, uterus, and cervix of each sow revealed no spirochetes. Attempts to isolate mycoplasmas and chlamydiae from mammary gland, uterine tube (fallopian tube), uterus, cervix, and urethra of the 24 sows were negative. The evidence confirms previous reports that coliforms are the most significant bacteria in mastitis of the sow.

Animals↗
PubMed1980

Comparison of selective culture and serologic agglutination of Treponema hyodysenteriae for diagnosis of swine dysentery.

Samples of faeces and serum were collected from pigs of various ages on 21 farms. Faecal samples were cultured on trypticase soy agar containing 5% citrated bovine blood and 400 microgram per ml spectinomycin, incubated at 42 degrees C in Gaspak jars under an atmosphere of 80% hydrogen: 20% carbon dioxide. Antibody titres to Treponema hyodysenteriae were determined by a microtitration agglutination method using merthiolate-inactivated whole cell antigen prepared from a beta- haemolytic isolate. Results indicated that mean titres in pigs from which beta- haemolytic T hyodysenteriae was isolated were significantly higher than in pigs which yielded isolates of weak beta- haemolytic T innocens or in culturally negative pigs (P less than 0.0225). Mean titres of herds where beta- haemolytic T hyodysenteriae was isolated were significantly higher (P less than 0.005) than the mean titres of either of the other two groups. However, mean titres of herds where no isolates were obtained were not significantly different from mean titres of herds where weak beta- haemolytic T innocens was isolated.

Agglutination Tests↗
PubMed1980

Immune responses after localized lung immunization in the dog.

The immune response in immunized and unimmunized bronchoalveolar spaces, as well as in the blood, was measured after localized deposition of antigen in the lung. Using a fiberoptic bronchoscope, groups of dogs were immunized with sheep red blood cells (SRBC) deposited into a single airway of the left apical or right apical lung lobes. Bronchoalveolar cells were obtained by lung lavage through the fiberoptic bronchoscope from the immunized lung lobe, as well as from lung lobes that did not receive antigen. Lavage cells and blood samples were collected at 3 to 21 days after immunization. The total number of lymphocytes, macrophages, and polymorphonuclear leukocytes, and the number of lymphoid cells producing anti-SRBC IgM and IgG antibodies were determined. Our results indicated that the highest number of antibody-forming cells (AFC) were found in the immunized lung lobes. An elevated, but significantly lower number of AFC were observed in the unimmunized lung lobes. The number of IgM and IgG AFC in the blood reached peak concentrations 3 to 7 days earlier than the AFC in the lung. We concluded from our data that the blood is an important source of the AFC found in the lung.

Animals↗
PubMed1980

Regional immunologic responses following localized deposition of antigen in the lung.

This study evaluates the immune response in individual lung-associated lymph nodes of beagle dogs after immunization in specific lung lobes. A particulate antigen, sheep red blood cells (SRBC), was used for immunization. The numbers of anti-SRBC antibody-forming cells (AFC) in the tracheobronchial and in the mediastinal lymph nodes were determined 5 days after deposition of SRBC in the left or right apical or left or right diaphragmatic lung lobes. Results indicated that translocation of the SRBC antigen to these lymph nodes was basically ipsilateral because larger numbers of antigen-specific AFC were consistently found in lymph nodes from the same side of the lung that received SRBC immunization. Of 16 dogs immunized, only two did not show ipsilateral antigen stimulation of the lung-associated lymph nodes. This variance occurred only in a single lymph node in each dog. Although the SRBC antigen induced AFC predominantly in the ipsilateral lymph nodes, some AFC were also found in the contralateral lymph nodes. The largest numbers of AFC in the contralateral tracheobronchial lymph nodes were found after immunization in the right apical or right diaphragmatic lung lobes.

Animals↗
PubMed1980

Lymphoid leukosis virus infection: effects on production and mortality and consequences in selection for high egg production.

Lymphoid leukosis (LL) is virus-induced, lymphoblastic malignancy of chickens that can be congenitally transmitted. Mortality from LL is generally low. Effects of LL virus (LLV) on production and mortality were investigated in approximately 2000 Leghorn pullets in each of two consecutive years. The pullets were from nine strains developed in Ottawa, of which three were unselected control strains and six were strains under selection for up to 27 generations for high egg production and a complex of related commercially important traits. The overall frequency of birds shedding LL virus of gs antigen into eggs (LL-S) was significantly lower in the selected strains (3.9%) than in the control strains (18.5%), indicating that LLV may have negative effects on production and cause elimination of LL-S birds by selection. Such significant effects were indeed detected: the LL-S pullets produced to 497 days of age in 1976 and 1977, respectively, 30 and 25 eggs less per hen-housed than the nonshedders. The LL-S birds matured sexually later, produced smaller eggs at a lower rate, and their eggs had a lower specific gravity, indicating thinner shells. Mortality from all causes to 497 days was significantly higher in LL-S birds (+14.8%) in 1976. In 1977 the increase (+5.5%) did not reach statistical significance. In both years the mortality from LL itself remained very low. In another study, eggs from one of the control strains were incubated and hatched from the dams were 291 and 483 days old. The eggs from LL-S dams had 2.4% lower fertility and 12.4% lower hatchability. The effects on hatchability were more pronounced in the older dams. Since the lower production of LL-S birds results in a lower frequency of such birds in strains selected for high egg production, it is suggested that a part of the difference between the performance of the selected and control strains (delta S) is due to reduction in the frequency of LL-S birds (delta L) rather than due to true genetic gain. In this study, the size of delta L relative to delta S was estimated at 4 to 14% for egg production and 3 to 7% for egg weight. The negative effects of LLV infection on egg production, mortality, hatchability, and genetic gains show the desirability of producing chickens free of LLV infection.

Animals↗
PubMed1979

Comparison of selective culture and serologic agglutination of Treponema hyodysenteriae for diagnosis of swine dysentery.

Samples of faeces and of serum were collected from pigs of various ages on 21 farms. Faecal samples were cultured on trypticase soy agar containing 5 per cent citrated bovine blood and 400 micrograms per ml spectinomycin, incubated at 42 degrees C in Gaspak jars under an atmosphere of 80 per cent hydrogen: 20 per cent carbon dioxide. Antibody titres to Treponema hyodysenteriae were determined by a microtitration agglutination method using merthiolate-inactivated whole cell antigen prepared from a beta-haemolytic isolate. Results indicated that mean titres in pigs from which beta-haemolytic T hyodysenteriae was isolated were significantly higher than in pigs which yielded isolates of weak beta-haemolytic T innocens or in culturally negative pigs (P less than 0.0225). Mean titres of herds where beta-haemolytic T hyodysenteriae was isolated were significantly higher (P less than 0.005) than the mean titres of either of the other two groups. However, mean titres of herds where no isolates were obtained were not significantly different from mean titres of herds where weak beta-haemolytic T innocens was isolated.

Agglutination Tests↗
PubMed1979

Pathogenic synergism between Treponema hyodysenteriae and other selected anaerobes in gnotobiotic pigs.

Gnotobiotic pigs were orally exposed to various anaerobes at 6 to 9 days of age and similarly inoculated with Treponema hyodysenteriae B204 3 to 6 days later. Watery diarrhea and fecal excretion of large quantities of mucus and some fibrin clots were observed 4 to 20 days after inoculation with B204 if other anaerobes were present. Colonic lesions characteristic of swine dysentery were observed when B204 was present with Fusobacterium necrophorum, three strains of Bacteroides vulgatus, a Clostridium species, and Listeria denitrificans individually and when some of these microbes were present in various combinations, but not when B204 was present alone. These results are consistent with the conclusion that T. hyodysenteriae is the primary pathogen in the etiology of swine dysentery and that the presence of one or more other anaerobes is a prerequisite for expression of pathogenicity of T. hyodysenteriae. This prerequisite can be met by a variety of anaerobes.

Anaerobiosis↗
PubMed1979

Methods to evaluate the effects of toxic materials deposited in the lung on immunity in lung-associated lymph nodes.

Intratracheal instillation of sheep red blood cells (SRBC) induced a primary immune response in lung-associated lymph nodes of Chinese hamsters and Fischer-344 rats. Few or no anti-SRBC antibody forming cells (AFC) were found in the spleen or cervical lymph nodes after intratracheal immunization. The number of AFC was significantly suppressed in the lung-associated lymph nodes from hamsters exposed by inhalation of 239PuO2 and in rats exposed by intratracheal instillation of benzo(a)pyrene (BaP). Although the immunologic function of the lung-associated lymph nodes was suppressed by 239PuO2 and BaP exposure, there was no observable increase in the number of AFC in distant lymphoid tissues. These data indicate that damage to lung cells and/or cells in lung-associated lymph nodes can suppress immunity induced by deposition of antigen in the lung. Even though lung-associated lymph nodes in exposed animals contained lower numbers of AFC, antigen instilled into the lungs of exposed animals did not significatnly translocate to distant lymphoid tissues. This indicates that the antigen filtering capacity of the lung-associated lymph nodes was not altered.

Aerosols↗