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Biomedical subjects

R L Kerlin

Publications and source records attributed to R L Kerlin.

30 records · Page 2Linked to original sources
PubMed1988

Modulation of IgG subclass expression during antibody responses in sheep.

Experiments were undertaken to investigate IgG subclass expression during epitope-specific antibody responses in sheep. Animals were immunised with conjugates of bovine serum albumin-DNP (BSA-DNP), or killed Staphylococcus aureus-DNP (Sa-DNP) alone or with muramyl dipeptide (MDP), dextran sulphate (DXS), or staphylococcal exotoxins (toxin). Sheep received two injections of the same preparation intracutaneously at six weeks interval. Total and IgG subclass-specific anti-DNP, and anti-carrier (BSA or S aureus) antibody levels were measured by ELISA in blood taken at weekly intervals before and after immunisation. Anti-DNP antibody levels in animals given Sa-DNP alone were considerably greater than in those immunised with BSA-DNP alone. Toxin suppressed antibody responses to DNP and both carriers; MDP suppressed anti-hapten antibody responses below the levels obtained with antigen alone. Neither toxin nor MDP significantly altered the IgG subclass profile of antibody to DNP bound to either carrier. DXS did not significantly change total levels of anti-DNP antibody measured in sheep given BSA-DNP or S aureus-DNP. However, DXS promoted IgG1 and suppressed IgG2 anti-DNP antibody responses during the secondary response to Sa-DNP but not to BSA-DNP.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1987

Inflammatory and immunological responses in skin and peripheral lymph of sheep following intracutaneous injection of Staphylococcus aureus.

The cellular response within lesions and in draining lymph was examined in sheep following a primary intracutaneous injection of live or killed S. aureus. Microscopic examination of sections from live S. aureus lesions (12, 24, 48, and 96 h following vaccination) revealed a high ratio of neutrophils to macrophages at all times. This ratio was initially high following inoculation of killed S. aureus but decreased steadily at successive sampling times. Representative sections from lesions were subjected to indirect immunofluorescent staining to identify IgM-, IgG1-, and IgG2-containing cells. The ratio of IgG2- to IgG1-containing cells in lesions produced following live S. aureus vaccination was significantly greater than the ratio in lesions produced by killed staphylococci. Lesions induced by live S. aureus recruited significantly greater numbers of 51Cr-labeled allogeneic neutrophils from blood than did lesions induced by killed S. aureus. During the first 6 h this difference was approx. 20-fold. The volume of lymph and the number of leukocytes draining live S. aureus lesions was considerably greater than from lesions produced by killed staphylococci. The proportion of neutrophils in lymph draining both types of lesions increased markedly during the first two days of the response but was observed to be greater and remained higher for a longer period of time in lymph draining vaccine lesions produced following injection of live staphylococci. The increase in proportion of neutrophils in lymph was accompanied by a concomitant decrease in proportion of lymphocytes and macrophages. No immunoglobulin-containing cells or anti-staphylococcal antibody production was detected in lymph draining either type of lesion. These differences in inflammatory responses may contribute to the documented differences in immune responses to live and killed staphylococcal vaccines.

Animals↗
PubMed1987

Effect of dextran sulphate on IgG subclass of antibody in efferent popliteal lymph of sheep.

IgG1 and IgG2 participation in anti-hapten, anti-carrier and immunoglobulin-containing cell (Ig-cc) responses was studied in sheep immunised with killed Staphylococcus aureus-Dinitrophenyl (DNP) conjugates. The antigen was given with or without the polyanionic adjuvant dextran sulphate (DXS). Animals were immunised intracutaneously on the lateral hock of one hind leg with 1 X 10(9) S. aureus-DNP with or without 20 mg DXS. Six weeks later, primed sheep underwent surgery to cannulate an efferent popliteal lymphatic vessel in the immunised leg. Forty-eight hours after surgery, each sheep was given a further intracutaneous injection of 1 X 10(9) S. aureus-DNP with or without 20 mg DXS adjacent to the primary injection site. IgG1-cc and IgG2-cc in lymph were counted using indirect immunofluorescence. Total IgG1 and IgG2 anti-staphylococcal and anti-DNP antibody output in lymph was determined using enzyme-linked immunosorbent assays (ELISA's). DXS markedly increased antibody responses to S. aureus-DNP in the popliteal lymph node of sheep and was shown to strongly enhance immunological memory. The ratios of IgG2-cc:IgG1-cc and IgG2:IgG1 anti-staphylococcal antibody in lymph-draining popliteal lymph nodes of sheep stimulated with DXS and S. aureus-DNP was significantly greater than the same ratios in animals given antigen alone. The IgG subclass-specific immunomodulatory effects of DXS were exerted whether the adjuvant was given with primary and/or secondary inoculations. There was no difference in the ratio of IgG2:IgG1 anti-DNP antibody in lymph from animals given S. aureus-DNP with and without DXS.

Adjuvants, Immunologic↗
PubMed1987

The secondary immune response to Staphylococcus aureus vaccines in efferent popliteal lymph of sheep.

The secondary immune response to live and killed Staphylococcus aureus vaccines was studied in efferent popliteal lymph of sheep. Animals were immunized with either live or killed S. aureus intracutaneously on the lateral hock, in an area draining into the popliteal lymph node. Six weeks later, an efferent popliteal lymphatic vessel in the vaccinated leg was cannulated, and 48 hr after surgery a second inoculation (identical to the primary) was placed in the skin adjacent to the primary vaccination lesion. A dramatic decrease in lymphocyte output ('cell shutdown') was observed in lymph collected from sheep given the secondary inoculation of live S. aureus during the first 8 hr after inoculation. However, only a moderate decrease in lymphocyte output occurred in lymph from animals receiving killed S. aureus or from control animals. The proportion of eosinophils in lymph collected from animals given live S. aureus increased to a peak (14% of total leucocytes in lymph) between 6 hr and 8 hr, and returned to prechallenge levels by 24 hr post-inoculation. The percentage of neutrophils in lymph peaked between 8 hr and 1 day after injection of live bacteria. This granulocyte response was not observed in animals given killed S. aureus or control animals. IgM-, IgG1- and IgG2- containing cells (-cc) in lymph were quantified by indirect immunofluorescence. Animals given live S. aureus produced lymph with greater numbers of Ig-cc of these isotypes than those given killed organisms. The ratio of IgG2-cc:IgG1-cc was significantly greater in lymph from animals given live S. aureus from Day 2 to Day 6 post-challenge. IgM and IgG1 anti-staphylococcal antibody levels increased in lymph collected from all vaccinated animals, but only sheep given live S. aureus showed any increase in levels of IgG2 antibody.

Animals↗
PubMed1986

Variations in immunoglobulin isotype produced during the antibody response to Brucella abortus and Staphylococcus aureus vaccines in sheep.

Experiments in sheep were carried out to examine factors modifying the immunoglobulin (Ig) isotype of the antibody response to Brucella abortus. Live B abortus (S19) stimulated higher titres of agglutinating antibody and IgG1 and IgG2 antibody than did killed B abortus. Live B abortus stimulated a more protracted synthesis of IgG2 antibody during the primary and secondary responses than did the killed S19 vaccine. In a second experiment, the capacity of live and killed Staphylococcus aureus to modify the antibody response to killed B abortus was examined. Both live and killed S aureus enhanced production of anti-brucella antibodies; this response was attributed to the adjuvant properties of S aureus. Killed S aureus enhanced production of anti-brucella antibody to a greater extent than live S aureus. Live S aureus did not preferentially enhance production of IgG2 anti-brucella antibody. The results suggested that the enhanced production of IgG2 antibody induced by live vaccines does not depend solely on a pyogenic lesion at the vaccination site.

Adjuvants, Immunologic↗
PubMed1986

Lymph drainage from the mammary gland in sheep.

Lymph from the mammary gland passes through at least three lymph nodes. These are usually the mammary, iliofemoral and medial iliac, although the subiliac, internal inguinal and sacral lymph nodes may also be involved. The iliofemoral, a large, flattened node in the dorsolateral wall of the pelvis, receives lymph from subiliac and popliteal as well as mammary nodes. Afferent lymphatic vessels either enter the subcapsular sinus on the dorsal surface of this node, or penetrate more deeply into the node. Lymphatics carrying mammary lymph enter more caudally than those from the popliteal or subiliac lymph nodes. Evans blue dye, injected into the mammary gland, showed a characteristic distribution within the mammary and iliofemoral nodes. Within the iliofemoral nodes it was present mainly in the caudal part. However, when China ink was used, carbon particles were distributed throughout most of the ipsilateral mammary nodes. In the iliofemoral node the carbon was distributed more widely than the Evans blue; it was found, mostly within macrophages, over the whole length of the node. A similar distribution of carbon was seen when it entered from the popliteal node. It appears likely that, although lymph from the mammary gland shows some preference for the caudal part of the iliofemoral node, constituents of this lymph may mix within the node with lymph from other primary nodes.

Animals↗
PubMed1986

Afferent pathways of lymph flow within the popliteal node in sheep.

Lymph enters the popliteal node in sheep either at the subcapsular sinus, or through terminal afferent lymphatics which pass within trabeculae to medullary sinuses. Lymph from the subcapsular sinus traverses trabecular sinuses and/or a network of tubular sinuses in the cortex before entering the medullary sinuses, which are very extensive. Carbon particles, injected either into an afferent lymphatic or subcutaneously into the leg, were initially found mainly in a circumscribed area of the subcapsular sinus. Within a few hours they were present within macrophages in and around medullary sinuses in a band which extended around virtually the whole medulla. It was concluded that the pathways taken by lymph constituents in the sheep node may differ from those described for mice, rats and rabbits.

Afferent Pathways↗
PubMedDate not supplied

Sonographic renal findings in 20 dogs with leptospirosis.

Abdominal ultrasound examinations of 20 dogs with confirmed leptospirosis were reviewed retrospectively for renal abnormalities. Three dogs had a normal ultrasound examination. The remaining 17 dogs had sonographic abnormalities of the kidneys. These abnormalities, seen either alone or in combination, included renalmegaly (n=10), pyelectasia (n=9), increased cortical echogenicity (n=15), perinephric effusion (n=5), and a medullary band of increased echogenicity (n=6). At our institution, the medullary band of increased echogenicity has only been seen in dogs with leptospirosis and may therefore be a specific sonographic sign for this disease.

Animals↗
PubMedDate not supplied

A poorly differentiated germ cell tumor (seminoma) in a Long Evans rat.

A large neoplasm that replaced 1 testis of a Long Evans Rat was noted at the final necropsy of a dietary 2-yr study. By light microscopy, the morphological features were consistent with a poorly differentiated seminoma. Ultrastructurally, the cells were polygonal, had a round nucleus, had straight cellular boundaries, and bore no resemblance to Sertoli cells. Although there was little evidence of spermatocytic differentiation, the presence of proacrosomal granules and vesicles, prominent Golgi apparatus, tight intercellular junctions, and a few centriolar pairs without axoneme development, in conjunction with the absence of lipid droplets or abundant smooth endoplasmic reticulum, supported the diagnosis of seminoma rather than Leydig cell tumor. The cells were S-100- and vimentin-positive, although cytokeratin- and alpha-fetoprotein-negative. Seminomas are extremely rare neoplasms in rats; this is the first report in this strain and the first extensive analysis of a rat seminoma without spermatocytic differentiation.

Animals↗
PubMedDate not supplied

Histologic lesions in cynomolgus monkeys (Macaca fascicularis) naturally infected with simian retrovirus type D: comparison of seropositive, virus-positive, and uninfected animals.

Simian retrovirus (SRV) type D is a common cause of simian acquired immunodeficiency syndrome (SAIDS), a usually fatal immunosuppressive disease of macaques. Associated gross and histologic lesions have been well described for the rhesus macaque (Macaca mulatta) in experimental and natural infections. However, morphologic changes induced by this virus at the gross and light-microscopic level have not been documented in the cynomolgus macaque (Macaca fascicularis). In 1996, sporadic cases of anemia, weight loss, and diarrhea were noted in a colony of cynomolgus macaques in our research facility. Out of 28 animals, 24 tested positive for SRV by serology or virus isolation. Animals could mainly be classified into 1 of 2 categories: 1) positive for virus isolation but negative for SRV antibody and 2) negative for virus isolation but antibody positive. During the process of eliminating the virus from the colony, a complete postmortem examination was performed on the 24 infected animals that had to be culled. Twelve SRV-negative animals were available as controls. Minimal to mild follicular lymphoid infiltrates were seen in various organ systems in 75% of the negative animals, compared with moderate to marked infiltrates in 83% of infected animals. Lymphoid infiltrates were more common in the brain, bone marrow, and salivary gland of viremic animals and were rare to nonexistent in seropositive or negative animals. Lymphoid hyperplasia was present in 38% of the infected animals, whereas lymphoid depletion was seen in 47% of the infected animals. Overall, lesions were of greater severity in viremic animals than in virus-negative or seropositive animals. Overall, infected animals had lower, statistically significant hematocrit and lymphocyte values. Viremic animals had significantly lower hematocrit, white blood cell, lymphocyte, and neutrophil values than did controls. Only 1 out of 24 infected animals had clinical signs that were consistent with the definition of SAIDS, and none had evidence of opportunistic infections. Lesions were similar to those already reported in other species of macaques, but the absence of severe illness that was consistent with SAIDS in most viremic animals suggests that there may be a different manifestation of disease in the cynomolgus.

Animals↗
PubMedDate not supplied

Aggressive, undifferentiated sarcoma with widespread metastasis in a six-month-old Neopolitan mastiff.

A six-month-old Neopolitan mastiff presented for a rapidly growing cervical mass. Undifferentiated sarcoma was diagnosed at post mortem based on histopathology and immunohistochemistry. Metastases to mediastinum, pleura, lungs, liver, kidneys, omentum, mesentery, and multiple lymph nodes were present. Soft-tissue sarcomas are reported infrequently in children and young dogs. The cell of origin often is difficult to determine due to poor differentiation and rapid growth of these neoplasms.

Animals↗