Biomedical subjects

Elisabeth M Liebler-Tenorio

Publications and source records attributed to Elisabeth M Liebler-Tenorio.

5 recordsLinked to original sources

PubMed2006

MALT structure and function in farm animals.

Mucosa-associated lymphoid tissue (MALT) is defined as an organized lymphoid tissue in the mucosa that samples antigens. The morphological characteristics that distinguish MALT from lymphoid infiltrates are discussed. MALT has been extensively investigated in laboratory animals, while knowledge in cattle, sheep, goats, pigs and horses that are summarized under the term farm animals in this review is fragmentary. Literature data about the distribution, morphology, function and involvement in infectious diseases of MALT in farm animals are described. The understanding of specific features of MALT in other species than laboratory animals is important for comparative research, in order to understand pathological and immunological processes in the respective species and as a potential route of vaccination of mucosal surfaces.

Animal Diseases↗

PubMed2006

Detection of rotaviruses and intestinal lesions in broiler chicks from flocks with runting and stunting syndrome (RSS).

The intestinal tract and intestinal contents were collected from 34 stunted, 5-to-14-day-old broiler chicks from eight flocks with runting and stunting syndrome (RSS) in Northern Germany to investigate intestinal lesions and the presence of enteric pathogens with a special focus on rotaviruses (RVs). Seven chicks from a healthy flock were used as controls. Severe villous atrophy was seen in chicks from six flocks with RSS but not in the control flock. Lesions were often "regionally" distributed in the middle-to-distal small intestine. Transmission electron microscopy (TEM), polyacrylamide-gel electrophoresis (PAGE), reverse-transcriptase polymerase chain reaction (RT-PCR), and seminested RT-PCR were used for detection and characterization of RVs. The PAGE allows discrimination of different RV groups, and the RT-PCR was used to verify the presence of group (gp) A RVs. RVs were detected (by all methods) in 32 of 34 chicks from the flocks with RSS. By TEM (negative staining), RV particles were observed in intestinal contents of 28 chicks from the flocks with RSS. PAGE analysis showed four RV groups: gpA, gpD, gpF, and gpG. Group A RVs were detected in four chicks from two flocks with RSS, without intestinal lesions. GpD RVs were detected in 12 chicks of five flocks with RSS, 10 of them with severe villous atrophy. GpF RVs were confirmed in four chicks from three flocks with RSS and in two birds in the control flock. GpG RVs were verified in two chicks from two flocks with RSS, one with, and one without, intestinal lesions. At present, PCR methods are only available for detection of gpA RVs. Using RT-PCR, gpA RVs were identified in samples from 22 chicks including samples of two chicks from the control flock. Statistical analysis revealed a positive correlation between presence of gpD RV and severe villous atrophy in flocks with RSS. The results suggest that gpD RV plays a major role in the pathogenesis of RSS.

Animals↗

PubMed2004

Distribution of viral antigen and tissue lesions in persistent and acute infection with the homologous strain of noncytopathic bovine viral diarrhea virus.

Viral distribution and lesions were compared between calves born with persistent infection (PI) and calves acutely infected with the same bovine viral diarrhea virus (BVDV) isolate. Two PI calves from 1 dairy herd were necropsied. The PI viruses from these calves were isolated, characterized by sequencing, and found to be identical. This virus strain, designated BVDV2-RS886, was characterized as a noncytopathic (ncp) type 2 BVDV. To establish acute infections, BVDV2-RS886 was used to inoculate clinically healthy, seronegative calves which were 3 weeks to 3 months old. Nine calves received 10(6)-10(7) tissue culture infective dose of BVDV2-RS886 intranasally. Four additional age-matched animals served as noninfected controls. Infected calves were necropsied at 3, 6, 9, or 13 days postinoculation (dpi). Viral antigen was detected by immunohistochemistry in frozen sections, and lesions were evaluated in hematoxylin eosin-stained paraplast sections. In the PI calves, a wide distribution of viral antigen was found in all tissues and was not associated with lesions. In the acutely infected calves, viral antigen was widespread in lymphoid tissues at 6 dpi but had been mostly eliminated at 9 and 13 dpi. Depletion of lymphoid tissues was seen at 6, 9, and 13 dpi and repopulation at 9 and 13 dpi. In 1 of the calves at 13 dpi, severe arteritis was present in lymph nodes and myocardium. This comparison shows that an ncp BVDV strain that causes no lesions in PI animals is able to induce marked depletion of lymphoid tissues in calves with acute infection. Therefore, the failure to eliminate PI cattle from a herd causes problems not only in pregnant cattle but may also affect other age groups.

Animals↗

PubMed2003

Distribution of viral antigen and development of lesions after experimental infection of calves with a BVDV 2 strain of low virulence.

To examine the virus-host interaction in subclinical bovine viral diarrhea virus (BVDV) infections, the spread of a BVDV 2 strain of low virulence to different organs and the development of lesions were investigated. Eight colostrum-deprived, clinically healthy, 2-3-month-old calves were intranasally inoculated with 10(6) tissue culture infective dose of the naturally occurring BVDV 2 strain 28508-5 of low virulence, and 2 served as controls. Two calves each were euthanized at days 3, 6, 9, and 13 postinoculation (pi). Representative tissues were processed for histology and immunohistology. Signs of overt clinical disease were absent. However, a mild temperature elevation at days 7 or 8 pi and a moderate decrease of circulating lymphocytes occurred in all inoculated calves. The BVDV antigen was detected at day 3 pi in several lymphoid tissues. At day 6 pi, BVDV antigen was found widespread in lymphoid tissues and multifocally in intestinal epithelial cells but was associated with no or subtle lesions only. At day 9 pi, much less BVDV antigen was detectable, but there was severe depletion of lymphoid tissues. At day 13 pi, BVDV antigen had been cleared from most lymphoid tissues that were at variable phases of depletion and recovery. In conclusion, the BVDV strain of low virulence spread to lymphoid tissues and intestinal epithelial cells but was rapidly eliminated. Transient depletion of lymphoid tissues was followed by recovery.

Animals↗

PubMed2002

Distribution of viral antigen and development of lesions after experimental infection with highly virulent bovine viral diarrhea virus type 2 in calves.

OBJECTIVE: To correlate tissue distribution with development of lesions after experimental infection with a virulent strain of noncytopathic bovine viral diarrhea virus (BVDV) type 2 in calves. ANIMALS: Ten 14-day-old and two 2-month-old colostrum-deprived calves. PROCEDURE: Calves were intranasally inoculated with BVDV type-2 strain 1373 from an outbreak of clinically severe bovine viral diarrhea (BVD). Two 14-day-old calves served as noninfected controls. Two calves each were euthanatized on postinoculation days 3, 6, and 12, and 1 each on days 8, 9, 13, and 14. Tissues were collected for immunohistologic and histologic examination. RESULTS: Inoculated calves developed nonspecific clinical signs characterized by high fever and decreased numbers of leukocytes and thrombocytes. Viral antigen was detected focally in lymphoid tissues on day 3. On days 6, 8, 9, 12, and 14, viral antigen became increasingly widespread throughout organs and tissues. Viral antigen in lymphoid tissues was associated with severe depletion of all compartments. Lesions in other tissues were not well correlated with distribution of viral antigen. Depletion of lymphoid tissues was observed in a calf on day 13, but viral antigen had been cleared from most tissues and was detected in vascular walls only. CONCLUSIONS AND CLINICAL RELEVANCE: Infection with a virulent BVDV strain resulted in wide dissemination of viral antigen in host tissues. Severe lymphoid depletion developed in lymphoid tissues, whereas viral antigen was generally not associated with lesions in other tissues. Findings suggest that development of lesions in acute BVD is not solely a function of viral replication and is also attributable to host reaction to infection.

Animals↗