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Biomedical subjects

P Lind

Publications and source records attributed to P Lind.

At least 19 recordsLinked to original sources
PubMed2006

Short-term study of the uptake of PrP(Sc) by the Peyer's patches in hamsters after oral exposure to scrapie.

The disease-associated prion protein (PrP(Sc)) has been detected in the ileal Peyer's patches of lambs as early as one week after oral exposure to scrapie. In hamsters, the earliest reported time of PrP(Sc) detection in the Peyer's patches after oral exposure to scrapie is 69 days post-infection. To evaluate the acute uptake of inoculum and to investigate whether the Peyer's patches constitute the primary site of entry for scrapie after oral exposure, hamsters were each exposed orally to 1 ml of a 10% brain homogenate from hamsters in the terminal stage of infection with the 263 K strain of the scrapie agent. PrP(Sc) was demonstrated in the Peyer's patches only a few days after exposure, i.e., much earlier than previously reported. This study supports the view that the Peyer's patches constitute at least one of the primary entry sites of PrP(Sc) after oral exposure to scrapie.

Animals↗
PubMed2006

Receptor activator of nuclear factor kappaB ligand and osteoprotegerin in men with thyroid cancer.

BACKGROUND: Suppressive thyroid hormone therapy is generally a lifelong treatment for patients with differentiated thyroid cancer (DTC). However, long-standing thyrotropin (TSH) suppression is a risk factor for osteoporosis. Osteoprotegerin (OPG) and receptor activator of nuclear factor kappaB ligand (RANKL) are central regulators of bone turnover. The aim was to analyze the effects of a suppressive thyroid hormone therapy in males with DTC on the OPG/RANKL system and on bone metabolism. PATIENTS AND METHODS: The OPG and soluble RANKL (sRANKL) were determined in 40 men (mean age, 53.2 years) with DTC on suppressive thyroid hormone therapy (TSH; 0.053 +/- 0.037 mU L(-1), duration 5.7 +/- 4.4 years) and 120 healthy controls matched for age. The markers of bone metabolism were C-terminal telopeptide of type I collagen in serum (sCTx) and osteocalcin (OC). RESULTS: The control group had OPG values (mean +/- SD) of 1.9 +/- 1.0 pmol L(-1) and sRANKL values of 0.40 +/- 0.62 pmol L(-1). In patients with DTC, results for OPG were 3.03 +/- 1.04 pmol L(-1) (P < 0.05) and for sRANKL were 0.13 +/- 0.16 pmol L(-1) (P < 0.05). The control group presented values for sCTx of 2669 +/- 1132 pmol L(-1) and for OC of 17.89 +/- 6.5 ng mL(-1). Patients with DTC on suppressive thyroid hormone therapy had increased sCTx values of 3810 +/- 2020 pmol L(-1) (P = 0.03) but comparable OC values of 19.21 +/- 7.67 ng mL(-1) (NS). CONCLUSIONS: Suppressive thyroid hormone therapy in men with DTC increased bone degradation and induced significant changes in the OPG/RANKL system. These changes include, besides the risk of osteoporosis, possible negative effects on the vascular function and an increased risk of cardiovascular disease.

Adult↗
PubMed2006

Use of IgG avidity ELISA to differentiate acute from persistent infection with Salmonella Dublin in cattle.

AIMS: To investigate whether an immunoglobulin (Ig)G avidity ELISA can be used to differentiate between acute and persistent infection with Salmonella (S.) Dublin in cattle. To determine whether the IgG isotype, IgG(1) and IgG(2) responses in acute and persistent infections differ. METHODS AND RESULTS: Animals were selected from two herds with long-term infection (years) and two herds recently infected (<3 months). Forty-seven animals were categorized into groups based on the persistence of their antibody level in milk. Based on titre from two serial dilutions the avidity index (AI) was calculated for IgG (IgG-AI), IgG(1) (IgG(1)-AI) and IgG(2) (IgG(2)-AI). The mean IgG-AI for suspected carrier animals with either persistently high (group 1) or persistently high to medium high (group 2) antibody levels was significantly (P = 0.003) higher (32.1% and 38.4%) than for acutely infected animals (21.7% and 22.3%). The probability of being a suspect carrier was associated with IgG-AI, antibody level in the sample and age. However, the effect of age could be the result of a biased sample selection. Specificities and sensitivities were calculated at a range of cut-off values for IgG-AI and IgG(1)-AI. Overall, IgG(2)-AI was high compared with IgG(1)-AI, and there was no difference in IgG(2)-AI between infection groups. There was no difference in the ratio IgG(2):IgG(1) for acute and persistent infection groups. CONCLUSIONS: Assuming that a persistently high antibody response is indicative of persistent infection with S. Dublin in cattle, it can be concluded that the IgG-AI can aid in differentiating between acute and long-term infection on herd level. However, for the test to be useful as an alternative tool to repeated sampling over time for detection of persistently infected carriers during control strategies in cattle herds, the test needs to be optimized and studied further in a larger sample of well-characterized infections in cattle. The affinity of IgG(2) is higher than IgG(1) early in the S. Dublin infection. There appears to be no difference in the IgG(2)-AI between the acute and chronic infection stages. SIGNIFICANCE AND IMPACT OF THE STUDY: For decades the strategies for detection of persistently infected cattle in S. Dublin infected herds have involved repeated bacteriological culture of faecal samples or repeated antibody measurements over several months. Both methods are time consuming and costly, leaving a new method for detection of carrier animals based on a single sampling highly desirable. This study illustrates a tool, IgG-AI, which may prove useful, although more validation of the method is required before it is used in practice.

Acute Disease↗
PubMed2005

Plasma fibrinogen level and the risk of major cardiovascular diseases and nonvascular mortality: an individual participant meta-analysis.

CONTEXT: Plasma fibrinogen levels may be associated with the risk of coronary heart disease (CHD) and stroke. OBJECTIVE: To assess the relationships of fibrinogen levels with risk of major vascular and with risk of nonvascular outcomes based on individual participant data. DATA SOURCES: Relevant studies were identified by computer-assisted searches, hand searches of reference lists, and personal communication with relevant investigators. STUDY SELECTION: All identified prospective studies were included with information available on baseline fibrinogen levels and details of subsequent major vascular morbidity and/or cause-specific mortality during at least 1 year of follow-up. Studies were excluded if they recruited participants on the basis of having had a previous history of cardiovascular disease; participants with known preexisting CHD or stroke were excluded. DATA EXTRACTION: Individual records were provided on each of 154,211 participants in 31 prospective studies. During 1.38 million person-years of follow-up, there were 6944 first nonfatal myocardial infarctions or stroke events and 13,210 deaths. Cause-specific mortality was generally available. Analyses involved proportional hazards modeling with adjustment for confounding by known cardiovascular risk factors and for regression dilution bias. DATA SYNTHESIS: Within each age group considered (40-59, 60-69, and > or =70 years), there was an approximately log-linear association with usual fibrinogen level for the risk of any CHD, any stroke, other vascular (eg, non-CHD, nonstroke) mortality, and nonvascular mortality. There was no evidence of a threshold within the range of usual fibrinogen level studied at any age. The age- and sex- adjusted hazard ratio per 1-g/L increase in usual fibrinogen level for CHD was 2.42 (95% confidence interval [CI], 2.24-2.60); stroke, 2.06 (95% CI, 1.83-2.33); other vascular mortality, 2.76 (95% CI, 2.28-3.35); and nonvascular mortality, 2.03 (95% CI, 1.90-2.18). The hazard ratios for CHD and stroke were reduced to about 1.8 after further adjustment for measured values of several established vascular risk factors. In a subset of 7011 participants with available C-reactive protein values, the findings for CHD were essentially unchanged following additional adjustment for C-reactive protein. The associations of fibrinogen level with CHD or stroke did not differ substantially according to sex, smoking, blood pressure, blood lipid levels, or several features of study design. CONCLUSIONS: In this large individual participant meta-analysis, moderately strong associations were found between usual plasma fibrinogen level and the risks of CHD, stroke, other vascular mortality, and nonvascular mortality in a wide range of circumstances in healthy middle-aged adults. Assessment of any causal relevance of elevated fibrinogen levels to disease requires additional research.

Adult↗
PubMed2005

Clinical experience with a commercially available negative oral contrast medium in PET/CT.

PURPOSE: To evaluate a commercially available negative oral contrast material for PET/CT. MATERIAL AND METHODS: In a prospective series of 49 patients, Mukofalk, which is a vegetarian-based substance, was used as a negative oral contrast medium in whole body PET/CT studies. Mukofalk was administered during a time period of 1.5 hours before the examination. Quality of small bowl distension and eventual pathological tracer uptake in the intestine were evaluated. RESULTS: Distension of the small bowel was excellent or good in 41 (85 %) and poor in 8 (15 %) patients. Mild tracer uptake in the small bowel was observed in 5 patients (10.2 %) and moderate uptake in another 2 patients (4 %). In none of these patients did the F-18 FDG uptake interfere with image interpretation. CONCLUSION: Mukofalk can be used as a negative oral contrast medium in PET/CT studies.

Administration, Oral↗
PubMed2005

Preliminary characterisation of Toxoplasma gondii isolates from Zimbabwe, with stage-specific monoclonal antibodies.

Cell-culture-derived clones of eight Toxoplasma gondii isolates from Zimbabwe were characterised in IFAT with a panel of five monoclonal antibodies (mAb). Each clone had been established from a single murine brain cyst. The antibodies were bradyzoite-specific (4.3), tachyzoite-specific (4.25, 5.1 and anti-P(30)), or tachyzoite- and bradyzoite-specific (5.15). Their strong reactivity with the bradyzoite-specific mAb 4.3 and their weaker reactivity with the tachyzoite-specific 4.25, 5.1 and anti-P(30) indicated that all the isolates are probably of genetic type II. Each of the isolates reacted in the IFAT in a similar way to the Danish reference strain of T. gondii, SSI-119.

Animals↗
PubMed2005

Seroprevalence of Toxoplasma gondii infection in domestic pigs reared under different management systems in Zimbabwe.

Serum samples from 474 domestic pigs (Sus scrofa) from Zimbabwe were tested for anti-Toxoplasma gondii IgG antibodies using the indirect fluorescent antibody test. The results showed that T. gondii infection is widespread in Zimbabwean pigs. Seroprevalence was lowest in fattening pigs from large and small-scale commercial farms that practise good hygiene (19.75% of 238) and highest in backyard scavenging pigs (35.71% of 70). Only 11.7% (11) of the 127 positive samples had titres of > or = 1:400 and nine (81.82%) of these 11 originated from pigs reared under poor hygienic conditions. A prevalence of 3.51% was found in the same group of fattening pigs using an indirect IgG enzyme-linked immunosorbent assay at the single serum dilution of 1:400. The serosurvey shows the importance of modern intensive husbandry systems in reducing the prevalences of T. gondii infection in domestic pigs.

Abattoirs↗
PubMed2005

Seroprevalence of Toxoplasma gondii infection in goats and sheep in Zimbabwe.

Seroprevalence rates of Toxoplasma gondii anti-antibodies in adult goats and sheep from different parts of Zimbabwe were determined. A total of 225 (67.9%) of the 335 serum samples tested were positive for anti-T. gondii IgG antibodies with the indirect fluorescent antibody test. There were differences in antibody seroprevalences among communal land goats from the different agro-ecological zones (Natural regions llb and III: 80 and 96.7%, respectively; Natural region IV: 65.9%; Natural region V: 45%; and Natural region III had a significantly higher seroprevalence than IV and V. The highest seroprevalences found in Natural regions II b and Ill are likely to be linked to the existence of more households and hence the possibility of a higher concentration of domestic cats that increases the chances of environmental contamination with their faeces harbouring T. gondii oocysts. The seroprevalence rate in sheep from a large commercial farm (10%) was significantly lower than that of sheep reared under the communal grazing system (80%). Overall, significantly higher proportions of seropositive animals had antibody titres of 1:50 (34.2% of 225) and 1:100 (44% of 225) as compared to the 9.8% and 12% with antibody titres of 1:200 and > or =1:400, respectively.

Animal Husbandry↗
PubMed2004

Cross-sectional survey in pig breeding farms in Hesse, Germany: seroprevalence and risk factors of infections with Toxoplasma gondii, Sarcocystis spp. and Neospora caninum in sows.

A cross-sectional survey was performed to estimate the prevalences of antibodies to Toxoplasma gondii (ELISA, IFAT), Sarcocystis spp. (ELISA, using S. miescheriana as antigen) and Neospora caninum (ELISA, immunoblotting) in sows from breeding farms in southern Hesse, Germany. A total of 2041 plasma samples of sows from 94 randomly selected farms was examined. Data on farm profiles, husbandry management and sows were collected by a questionnaire and exploratively analysed. For T. gondii the ELISA results agreed well with the results obtained by IFAT (kappa=0.71). Antibodies to T. gondii were detected by ELISA in 19% of the sows. Sixty-nine percent of the farms had at least one seropositive sow, and a within-farm seroprevalence of >or=50% was observed in 14% of all farms. The prevalence of anti-T. gondii antibodies was positively correlated with the age of sows. The within-herd seroprevalence was significantly higher in farms with reproductive disorders than in those without such problems. On the farm level, the farm type 'piglet production' (versus 'pedigree breeding' or 'farrow-to-finish') was the only risk factor associated with the presence of T. gondii-seropositive sows. Antibodies to Sarcocystis spp. were found in 29% of the sows. Seventy-two percent of the farms harboured at least one seropositive sow, and a within-farm seroprevalence of >or=50% was detected in 23% of all farms. The seroprevalence increased significantly with the age of sows. On the farm level, only the farm type 'piglet production' (versus 'pedigree breeding') and the replacement of sows by purchasing (versus raising on the own farm) were identified as risk factors for seropositivity. Antibodies to N. caninum were detected in one sow using both the screening ELISA and the confirmatory immunoblotting technique. This may indicate the first natural N. caninum infection in pigs.

Age Factors↗
PubMed2004

Longitudinal study of interferon-gamma, serum antibody and milk antibody responses in cattle infected with Mycobacterium avium subsp. paratuberculosis.

During a 2-year study period, 252 animals from dairy herds infected with Mycobacterium avium subsp. paratuberculosis, and 119 animals from non-infected herds were subjected to repeated blood and faecal sampling. Animals were retrospectively grouped by infection status as infected, exposed (culture negative animals from infected herds), or non-infected animals, and by age, 12-23 months (1+ year), 24-35 months (2+ years), or 36 months and older (3+ years). Samples were collected for culture of faeces, assessment of interferon-gamma (IFN-gamma) secreted by M. paratuberculosis antigen stimulated whole-blood lymphocytes (IFN-gamma test), and measurement of antibody responses against M. paratuberculosis in serum and milk by an in-house absorbed ELISA. The IFN-gamma test diagnosed higher proportions of infected and exposed animals than the antibody ELISAs. The highest sensitivity of IFN-gamma test was in infected cattle of 2+ years of age. Receiver-operating characteristic (ROC) analyses supported the assumption that the IFN-gamma test had a better performance than antibody tests of animals of 1+ and 2+ years of age. However, for animals of 3+ years all tests performed equally well. Application of single sampling compared with repeated samplings showed better performance of the IFN-gamma test by repeated samplings, and the milk antibody ELISA in animals of 3+ years of age performed significantly better with repeated sampling compared with single sampling. In conclusion, the IFN-gamma test may be applied for screening of cattle of 1 and 2 years of age for exposure to M. paratuberculosis and the antibody ELISAs from 3 years of age.

Age Factors↗
PubMed2004

Risk of myocardial infarction and stroke in smokers is related to plasma levels of inflammation-sensitive proteins.

BACKGROUND: The extent to which differences in cardiovascular risk between smokers with similar daily tobacco consumption may be related to plasma levels of inflammation-sensitive proteins (ISP) and whether these proteins are associated with levels of carboxyhemoglobin (COHb%) have not been clarified. METHODS AND RESULTS: In a population-based cohort of 1489 never smokers, 1685 former smokers, and 2901 current smokers, aged 28 to 61 years, plasma levels of orosomucoid (alpha(1)-acid glycoprotein), alpha(1)-antitrypsin, haptoglobin, fibrinogen, and ceruloplasmin were measured. COHb% levels were available for 2098 of them. Incidence of myocardial infarction, stroke, and death were monitored over 18.7+/-4.7 years. The proportion with high ISP levels (ie, > or =2 ISP in the top quartile) increased progressively with daily tobacco consumption (P<0.01) and COHb% (P<0.01). In all smoking categories, the incidence of stroke, cardiac events, and death was related to ISP. In heavy smokers, high ISP levels were associated with adjusted relative risks of 1.57 (1.05 to 2.35) and 1.50 (1.11 to 2.03) for cardiac events and death, respectively. Corresponding figures for moderate and light smokers were 1.59 (1.13 to 2.24) and 1.14 (0.87 to 1.49), respectively, and 1.32 (0.95 to 1.85) and 1.48 (1.10 to 1.98), respectively. CONCLUSIONS: ISP levels are related to COHb% in smokers. High levels are associated with an increased cardiovascular risk.

Adult↗
PubMed2004

The effect of colostrum on pigs pre-natally or post-natally exposed to Schistosoma japonicum.

Pre-natal infection of Schistosoma japonicum in pigs may prove to be a useful model in shedding light on human pre-natal schistosomiasis. This study describes the effects of immune colostrum on worm burdens, tissue egg counts, liver pathology and crude worm or egg antigen-specific IgG and IgA responses, in groups of pigs pre-natally, pre-natally + post-natally or post-natally exposed to S. japonicum. Results suggest that pre-natal exposure and immune colostrum did not affect the establishment of a post-natal challenge infection. However, immune colostrum seemed to increase the levels of septal fibrosis in pre-natally exposed pigs. These findings indicate that further investigations will prove valuable, elucidating the influence of the parasitological and immunological status of the sow, on pre-natally exposed pigs, and on the ability of these pigs to develop resistance against S. japonicum later in life.

Animals↗
PubMed2004

Descriptive epidemiology of thyroid carcinoma in Carinthia, Austria: 1984-2001. Histopathologic features and tumor classification of 734 cases under elevated general iodination of table salt since 1990: population-based age-stratified analysis on thyroid carcinoma incidence.

INTRODUCTION: The aim of the study was to investigate the current thyroid carcinoma (TC) incidence in Carinthia, a former iodine-deficient, goiter-endemic region in Austria with approximately 550,000 inhabitants from 1984 to 2001. Using age-cohort analysis we analyzed the TC incidence under the impact of two regional risk factors: the contamination of Austrian soils by the radioactive fallout in from Chernobyl 1986 and the increased iodination of table salt in a general program of goiter prophylaxis begun in 1991. To evaluate the characteristics of TC incidence, we compared the results of the periods 1984-1989, 1990-1995, and 1996-2001. RESULTS: A total of 734 TC cases were diagnosed. Papillary, follicular, medullary, oxyphilic, and anaplastic TC accounted for 76%, 18%, 3%, 1%, and 2%, respectively. The female to male ratio was 3:1. The annual incidence rate increased by 8.05% in females and 11.6% in males. TC cases younger than 40 years of age accounted for 22.6%, with a rate increase of 18% per year in young males, the female-to-male ratio decreased from 8.3, 6.1, 2.7 younger than 40 in the compared periods. Along with a further increase in papillary TC incidence and papillary thyroid carcinoma (PTC) follicular thyroid carcinoma (FTC) ratio in the adult population, the ratio tended to decrease in the younger than 40-year-old population. T4 class TC and loco-regional lymph node involvement increased significantly. INTERPRETATION: The observed changes in TC incidence, particularly in the young population, as in adults, could be linked to the abovementioned risk factors involved in the initiation and early growth of TC, and iodine may play a role in stimulating overall thyroid activity.

Age Distribution↗
PubMed2004

Comparative studies of experimental oral inoculation of pigs with Ascaris suum eggs or third stage larvae.

This experimental study was designed to compare the acquired resistance in pigs to Ascaris suum eggs following 4-weekly oral immunizations with either 200 A. suum infective eggs or 50 A. suum third stage larvae (L3). The two immunized groups (n = 7) together with an unimmunized control group (n = 7) of pigs were challenged orally with 50 infective A. suum eggs per kilogram bodyweight on day 19 after the last immunization. Seven days post-challenge the group immunized with eggs showed signs of resistance as evidenced by reduced lung larval counts compared with the challenge control group. Such significant resistance was not observed in the L3-immunized group. However, a markedly increased inflammatory liver reaction and white spot formation was demonstrated in the L3-immunized pigs after challenge compared with both control animals and egg-immunized pigs. On the day of challenge only the egg-immunized pigs mounted an anti-Ascaris antibody response both in serum and in lung lavage fluid. Ascaris-antigen induced increased histamine release from peripheral leucocytes following both immunization and challenge could only be demonstrated in the egg-immunized pigs. On day 7 post-challenge local IgA-anti-Ascaris antibodies were further demonstrated in bile of the egg-immunized group and in the small intestine of both immunized groups. In conclusion, oral A. suum egg immunization of pigs induced a significant reduction in lung larval counts upon challenge. In contrast, oral L3 immunization seemed to prime the pigs as observed by the presence of stunted lung larval growth and increased liver reaction post-challenge with A. suum eggs.

Animals↗
PubMed2003

Cloning of a novel orphan G protein-coupled receptor (GPCR-2037): in situ hybridization reveals high mRNA expression in rat brain restricted to neurons of the habenular complex.

The family of G protein-coupled receptors (GPCRs) is one of the largest protein families in the mammalian genome. Receptors belonging to this class mediate the effects of very diverse ligands and are responsible for signaling events by affecting the activities of enzymes and ion channels. Here we describe the cloning and identification of GPCR-2037, a novel and previously not identified member of the large family of GPCRs. This orphan GPCR displays several typical features of family A type of GPCRs and shows highest homology with the galanin receptors 2 and 3. In rat brain, in situ hybridization showed that expression of GPCR-2037 mRNA was exclusively localized to neurons of the habenular complex. The expression was particularly prominent in the medial habenular nucleus, whereas the lateral habenular nucleus exhibited a lower number of labeled cells. The restricted and unique expression pattern of GPCR-2037 in the rat brain suggests a role for this orphan GPCR in the habenular complex, a brain structure implicated in the modulation of various physiological functions. Further studies involving the identification of the GPCR ligand will enable the functional characterization of this orphan receptor and its role in regulating the habenular complex.

Amino Acid Sequence↗
PubMed2003

Analysis of repeated tests for interferon-gamma (IFN-gamma) response and faecal excretion for diagnosis of subclinical paratuberculosis in Danish cattle.

A total of 315 cattle were tested for infection with Mycobacterium avium subsp. paratuberculosis (M. paratuberculosis) at three consecutive samplings, using the interferon-gamma (IFN-gamma) test on whole blood and bacteriological culture of faecal samples. Of 205 cattle from 10 infected herds 99 (48%) were positive in the IFN-gamma test on at least one sampling using "IDEXX-criteria" for interpretation, and of 110 cattle from five non-infected herds three (3%) were positive. Forty-four animals from infected and one from non-infected herds tested positive at all three samplings. Although support for the specificity of the IFN-gamma test was provided by these results, they also indicate problems with false positives. Approximately half of the positive animals did not give the same result at all three samplings, indicating that repeated testing increases the chance of detecting reactors. Changing, or fluctuating, IFN-gamma test results occurred most frequently in animals younger than 1 year, indicating that the IFN-gamma test should be applied only to animals 1 year and older. M. paratuberculosis was isolated from 16 (4%) of 371 cattle, all from infected herds. Fifteen culture-positive cattle tested positive at least once in the IFN-gamma test. It was not possible to predict from the IFN-gamma test result the number of animals that would eventually develop disease. However, the test may be useful to detect animals that have been exposed to M. paratuberculosis earlier in their lives, and the testing of young cattle could be included in a control program to check for the effectiveness of preventing transmission of infection to calves and to identify animals at risk of developing disease later in their lives.

Animals↗
PubMed2003

In utero infection with porcine reproductive and respiratory syndrome virus modulates leukocyte subpopulations in peripheral blood and bronchoalveolar fluid of surviving piglets.

It is well known that piglets congenitally infected with porcine reproductive and respiratory syndrome virus (PRRSV) can be viremic at birth, and that preweaning mortality due to secondary infections often increases during acute outbreaks of PRRS. Therefore, an immunosuppressive effect of in utero infection has been suggested. The aim of the present study was to characterise the changes of leukocyte populations in piglets surviving in utero infection with PRRSV. A total of 27 liveborn uninfected control piglets and 22 piglets infected transplacentally with a Danish strain of PRRSV were included. At 2 and 4 weeks of age, 21 of 22 (96%) and 7 of 14 (50%) examined infected piglets were still viremic, whereas PRRSV could not be detected in the six infected piglets examined at 6 weeks of age. Flow cytometry analysis was used to determine the phenotypic composition of leukocytes in peripheral blood and bronchoalveolar lavage fluid (BALF) of 2-, 4- and 6-week-old infected piglets and age-matched uninfected controls. The key observation in the present study is that high levels of CD8(+) cells constitute a dominant feature in peripheral blood and BALF of piglets surviving in utero infection with PRRSV. In BALF, the average high level of CD8(+) cells in 2-week-old infected piglets (33.4 +/- 12.6%) was followed by a decline to 7.3 +/- 3.0 and 11.1 +/- 3.0% at 4 and 6 weeks of age. BALF of control piglets contained 1.6 +/- 0.9, 2.3 +/- 1.8 and 1.9 +/- 0.5% CD8(+) cells, only. In peripheral blood, however, the average number of CD8(+) cells remained at high levels in the infected piglets throughout the post-natal experimental period (2.8 +/- 1.9, 2.9 +/- 1.8 and 3.2 +/- 1.7 x 10(6) CD8(+) cells/ml at 2, 4 and 6 weeks, respectively). In the controls, the average levels of CD8(+) cells were 0.9+/-0.2, 1.9 +/- 1.7 and 1.6 +/- 0.5 x 10(6)/ml, respectively. Furthermore, the numbers of CD2(+) , CD4(+)CD8(+) and SLA-classII(+) cells, respectively, in peripheral blood, together with the levels of CD2(+) and CD3(+) cells in BALF were increased in the infected piglets infected in utero compared to the uninfected controls. The kinetic analyses carried out in the present study reflect that in utero infection with PRRSV modulates immune cell populations in peripheral blood and BALF of surviving piglets. The observed changes are characterised by high levels of CD8(+) cells supporting an important role of these cells in PRRSV infection. The present results, however, do not support the existence of post-natal immunosuppression following in utero infection with PRRSV.

Aging↗