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Biomedical subjects

P Thomas

Publications and source records attributed to P Thomas.

At least 19 recordsLinked to original sources

Characterization of disorder in semiconductors via single-photon interferometry.

The method of angular photonic correlations of spontaneous emission is introduced as an experimental, purely optical scheme to characterize disorder in semiconductor nanostructures. The theoretical expression for the angular correlations is derived and numerically evaluated for a model system. The results demonstrate how the proposed experimental method yields direct information about the spatial distribution of the relevant states and thus on the disorder present in the system.

Journal Article↗

Impact of blood transfusions on outcome after pneumonectomy for thoracic malignancies.

The aim of the present study was to determine the risk factors and impact on outcome of blood transfusions following pneumonectomy for thoracic malignancies. A retrospective analysis of 432 consecutive patients was carried out, of whom 183 (42.4%) were transfused post-operatively. The associations between blood transfusions and 20 variables were assessed by univariate and multivariate analysis. Survival analysis included log-rank test and Cox regression model. Patient age, neoadjuvant treatment, completion pneumonectomy and extended procedures were independent predictors of transfusion. It was found that 30-day mortality increased significantly from 2.4% (no transfusion) to 10.9 and 21.9% ( 2 red blood cell packs, respectively). Blood transfusion was the strongest predictor of 30-day mortality (odds ratio (OR) 10; 95% confidence interval (CI): 3.7-27), respiratory failure (OR 19.2; 95% CI 7.4-49.4) and infectious complications (OR 3; 95% CI 1.5-6.2). In the 367 lung cancer patients, a significantly lower 5-yr survival was observed in univariate analysis of transfused patients (27.8+/-5.4% versus 39.4+/-4.5%). In a Cox regression analysis, blood transfusion was no longer found to be significant. A dose-related correlation is suggested between blood transfusion and early mortality through an increase of infectious and respiratory complications. In contrast, blood transfusion had no independent adverse impact on long-term survival.

Adult↗

Percutaneous repair of aortic aneurysms: a prospective study of suture-mediated closure devices.

PURPOSE: To evaluate prospectively the safety and efficacy of totally percutaneous placement of abdominal and thoracic aortic endografts using the Prostar XL suture-mediated closure system. METHODS: From January 2002 to January 2005, we attempted to insert percutaneously all bifurcated abdominal aortic and thoracic endografts. Consecutive patients (25 men, four women), with mean age 74.9 years (range 44-84), underwent endovascular repair for 20 abdominal aortic aneurysms (AAA) and nine thoracic aortic aneurysms (repeat operation in one case). Endografts used included 21 Zenith (Cook), eight Talent (Medtronic), one AneuRx (Medtronic). For the < > technique, two Prostar XL 8F were used to close 22-24F access sites and one Prostar XL 10F to close 16F access sites. RESULTS: Procedural success was achieved in 21/29 (72.4%) patients and in 39/47 access sites (83%). Closure of 22-24F access sites with tandem 8F Prostar devices was successful in 23/29 (79.3%) cases. Closure of 16F access sites with 10F Prostar device was successful in 16/18 (88.8%) cases. There were seven peri-procedural failures requiring surgery to repair the femoral artery in three cases. Four access complications healed without intervention. Overall 25/29 (86.2%) patients had complete percutaneous repair. No late complications were detected during follow-up (median 17.5 months). CONCLUSIONS: Percutaneous treatment of patients with AAA and thoracic aneurysms is feasible in most cases, with a very low risk of access-related complication, providing that the operator has sufficient practical experience of this technique.

Adult↗

[Allergy towards bone cement].

Bone cements based on polymethylmethacrylate are typically used for fixation of artificial joints. Intolerance reactions to endoprostheses not explained by infection or mechanical failure may lead to allergological diagnostics, which mostly focuses on metal allergy. However, also bone cement components may provoke hypersensitivity reactions leading to eczema, implant loosening, or fistula formation. Elicitors of such reactions encompass acrylates and additives such as benzoyl peroxide, N,N-dimethyl-p-toluidine, hydroquinone, or antibiotics (particularly gentamicin). Upon repeated contact with bone cement components, e.g., acrylate monomers, also in medical personnel occasionally hand eczema or even asthma may develop. Therefore, in the case of suspected hypersensitivity reactions to arthroplasty, the allergological diagnostics should include bone cement components.

Bone Cements↗

Directed forgetting in PTSD: a comparative study versus normal controls.

The most characteristic feature of Post-Traumatic Stress Disorder (PTSD) is the reexperiencing syndrome. The patient's memory seems to be fixed on the traumatic event, which may be due to disturbance of the autobiographic memory. To retrieve memories, others have to be inhibited. These inhibition mechanisms have been studied using the Directed Forgetting Paradigm, which measures the capacity to forget recently processed information and to retain the relevant information. Our hypothesis is that during PTSD, the memory is saturated with traumatic memories, so that the patients are no longer able to use the inhibitory processes. Therefore, during a Directed Forgetting Task (DFT) in which words "to remember" and words "to forget" are given, PTSD patients cannot inhibit the words "to forget", and so recall more words than the controls. We studied 30 patients with PTSD and compared them with 30 healthy controls, using DFT. The results show that the patients remembered significantly fewer words overall, and fewer of the words "to remember" than the controls, both for immediate and final recall. Our results are in favor of a reduction in directed forgetting in patients suffering from PTSD, resulting in difficulty in inhibiting irrelevant information from the overall information. There seems to be a deficit in the inhibitory processes in the memory in PTSD.

Adult↗

[Links between life events, traumatism and dementia; an open study including 565 patients with dementia].

SUMMARY: Ageing is due to a progressive loss of the person's adaptation capability, whereas during this period environmental aggression increases. In the elderly, life events re-present a psychological traumatism that overwhelms the old person and related family, disrupting and fragilising homeostatic balance. A number of authors have suggested a possible link between life traumatisms and the dementia processes. The aim of this study is to reveal the presence of life traumatisms preceding the apparition of the dementia syndrome. METHOD: This is a retrospective and comparative work based on the PIXEL study on complaints and demands from the principle informal caregivers of Alzheimer patients. It includes 565 patients presenting the criterion of dementia as defined by the DSM IV, and questionnaires filled out by the principle caregivers. One item of the questionnaire referred to life events which could have played a part in the development of the disorder. In a second stage, the reported events were classified into 4 distinct categories: loss, repeated or prolonged stress, psychotraumatism and depression-inducing events. The statistics were produced using SAS and Stat 10 software. Student's test, ANOVA and chi2-test were used. RESULTS: 372 caregivers answered the first item (65%); 76 of them believed there was no event while 296 related the disorder to one or several life events (79% of responders, 52% of the sample). These results confirm Persson and Clement's study which evidenced a higher frequency of stressing life events for subjects afflicted with dementia as compared with older people without any psychic disorder. Reported events and their respective frequency: spouse death (15.39%), parents' death (15%), familial difficulty (10.08%), anaesthesia (8.49%), child's death (4.42%), somatic disturbance (4%), depression (3.89%), retirement (3.89%), financial problems (2.65%), loneliness (2.65%), removal (1.76%), fall (1%), alcohol (0.8%), traumatism (0.53%), spouse care (0.35%), leaving for home care, storm and caregiver change in life (0.17%). Regrouping the data: 82.71% of the answers can be connected to prolonged stress, 62.85% to real or symbolic loss, 39% to a psychotraumatic event and finally, most of these events can potentially induce depression. DISCUSSION: Some of the events refer to difficulties concerning people close to the subject (death of a close relation, hospitalisation of husband or wife) in a period when the loss of autonomy or handicap means greater dependence on surrounding people. General anaesthesia is mentioned by 48 caregivers. In fact, this usually implies surgery, the presence of organic pathology or the need for hospitalisation, which we know has a destabilizing effect in the elderly. It is therefore not surprising that 23 answers mentioned somatic disorders (4% of the sample). According to Leger, it's mostly a loss type event which is implied in the elderly. Such losses would induce a weakening of cognitive stimulation which could decompensate an infraclinical dementia or accelerate an emerging dementia process. Antecedents of depressive illness are considered as an element of risk for the development of Alzheimer's disease. Depression is spontaneously mentioned by 22 caregivers. We must add the many reported life events which are well known to induce depression in older people. Most of the events considered in this study are liable to provoke manic mood swings. Depression resulting from life events can be considered either as an affection occurring along with dementia or as the aggravating factor of an infraclinical process or, finally, as an additional factor of vulnerability. With older people, many events may constitute a trauma because of the proximity of death and because of their sudden onset (fall, hospitalisation, somatic illness). Several studies have pointed out that a particularly traumatic event could enhance the risk of dementia. Life events associated with chronic or repeated stress are characterized by their permanence or their repetition. According to a general psychosomatic biological pattern, psychic distress will engender a series of degradations or an acute or chronic response to an early trauma. According to this hypothesis, prolonged exposure to an excess of glucocorticosteroids at the time of a disadaptative stress would have deleterious effects on the hippocampus. Indeed, the hippocampus plays a part in a number of functions affected by dementia such as memory, learning process and emotional adjustment. This study takes into account stress factors ("stressors") but not factors influencing their impact on the subject such as an individual predisposition (genetic, psychopathologic, coping abilities) and social support. The force of the impact of these events on older people and what is really experienced by them remain unknown. This study strengthens a number of others evincing an unusual frequency of life events in dementia processes. According to an integrative pattern, repeated or prolonged stress could be a deciding factor in the degenerative process or a factor of decompensation with older people presenting a genetic, biological or psychological vulnerability to dementia. The impact of such life events would vary according to the subject's pre-morbid personality, coping abilities and the support he/she can rely on. CONCLUSION: Some life events may be involved in the dementia process as shown by the results of this study, but this relationship does not imply direct causality. It's difficult to appreciate whether these results are not a consequence of the greater attention paid to the patient after the appearance of the first symptoms, leading to a closer observation. Stress could trigger the degenerative process. This argues for the necessity of an early diagnosis taking into account a traumatic event of life either precocious or late.

Aged↗

[MRI evaluation of cervicothoracic CSF hypotension].

We propose studying signs of cervicothoracic CSF hypotension by MRI. Axial T1-weighted GRE sequence with and without saturation bands positioned above and below the selected image plane, MR venography and MR Angiography with contrast administration are helpful to confirm the venous nature of the epidural thickening and to make the differential diagnosis with infectious or neoplastic epiduritis.

Adult↗

[Polymorphic light eruption: prophylaxis using a topical combination of antioxidants and UVA protection formulations].

BACKGROUND: In a recent randomized, double-blind, placebo-controlled clinical study, the efficacy of a combination consisting of 0.25% alpha-glucosyl-rutin, 1% vitamin E and a broad-spectrum, highly UVA-protective sunscreen (sun protector factor 15 - persistent pigmentation darkening 6) regarding prevention of polymorphous light eruption was well demonstrated. We evaluated this combination under real solar exposure conditions. PATIENTS AND METHODS: Patients with three previous typical polymorphous light eruptions (including one in the last year) were included in an open prospective multicenter study. The preparation was applied every two hours after the first summer exposure. No topical or systemic treatments presumed to be effective against polymorphous light eruption were given concomitantly. Evaluation was performed after the summer by a dermatologist. RESULTS: Two of the 54 patients dropped out of the study, one for an adverse effect (contact dermatitis). At the end of the study following application of the test preparation, no eruption was seen for 35 patients (67%), with minor eruption for 10 patients (19%) and an marked eruption for 7 patients (13%). Pruritus (present in all patients the year before) was not seen in 36 patients (69%), was considered bearable for 36 patients and unbearable for only 3 patients compared to 27 before inclusion. For the dermatologists, efficacy was excellent for 35 patients and good for 7 patients, giving global efficacy of around 80%, with inadequate results in 10% of cases (5 patients). Concerning protection against erythema, the test product reduced sunburn by 60% compared with the previous year. DISCUSSION: Because of the high clinical efficacy of the product noted after UVA challenge tests and verified by this clinical study under actual conditions of exposure, it may be proposed as a new prophylactic treatment for polymorphous light eruption.

Administration, Topical↗

[Allergic reaction to components of bone cement after total knee arthroplasty].

There are many reports about allergic reactions in association with total hip or knee arthroplasty. While most studies focus on allergic reactions to metallic components, only few reports exist about reactions to bone cement or its ingredients. We report about a patient who developed eczema at the knee and the lower leg one year after cemented TKR. Patch testing showed as potential causes contact allergic reactions to nickel and benzoylperoxide, an ingredient of the here used bone cement. The local and temporal association between onset of eczema and knee arthroplasty suggests a causal link. Benzoylperoxide as potential contact allergen in bone cement is so far almost neglected. The development of extended testing procedures and data collection should provide further information and better care of these patients. The development of special bone cements for patients with allergic diathesis is requested.

Arthroplasty, Replacement, Knee↗

Comparison of immunohistochemistry by automated cellular imaging system (ACIS) versus fluorescence in-situ hybridization in the evaluation of HER-2/neu expression in primary breast carcinoma.

AIMS: Immunohistochemistry (IHC) and fluorescence in-situ hybridization (FISH) are both commonly used assays for evaluation of HER-2/neu status in breast cancer. However, there is still no consensus on which method is most predictive of patient response to Herceptin. Recently, the automated cellular imaging system (ACIS) has been shown to improve the accuracy and reproducibility in scoring IHC. Our aim was to compare the results of HER-2/neu expression and gene amplification in the same patients by IHC using the ACIS system and by FISH. METHODS AND RESULTS: Two hundred and forty-seven breast cancer cases were studied. The concordance rate between IHC-ACIS (> or = 2.2) and FISH (> or = 2.0) was 94%. Fifteen patients were discordant; three had borderline FISH values and three had borderline IHC values. The other nine discordant cases consisted of five IHC-ACIS+, FISH- and six IHC-ACIS-, FISH+. HER-2/neu overexpression was more common in tumours that were high-grade, aneuploid, progesterone receptor and bcl-2 negative, with MIB-1 > 10%. CONCLUSION: HER-2/neu assessment by the ACIS is reliable, rapid and inexpensive, and correlates highly with results obtained by FISH.

Adenocarcinoma↗

Isolation of an ethanol-tolerant endospore-forming Gram-negative Brevibacillus sp. as a covert contaminant in grape tissue cultures.

AIMS: To characterize the alcohol-surviving bacterial isolate ARBG1 from in vitro grapes (Vitis vinifera). METHODS AND RESULTS: Two bacterial strains that survived in covert form in grape cultures were isolated from the spent alcohol used for disinfecting the tools of which one (ARBG2) was characterized earlier. The present study describes characterization of the second isolate, ARBG1. Nutrient agar (NA)-derived colonies of ARBG1 displayed consistently Gram-negative staining rods (2-4x0.5-0.6 micro) substantiated by KOH mucoid thread test. Older cultures (3-7 days) showed emergence of Gram-negative staining, oblong, phase-refractile cells with ellipsoidal spores. The growth and sporulation were modified by growth medium and incubation temperature with the optimum around 37 degrees C. Identification attempts involving microscopic, biochemical, Biolog or fatty acid profiling approaches brought in mixed and inconclusive results. PCR amplification of 16S rDNA was not successful with the standard primers 27F and 1492R but with 27F and a modified primer ARBG1-RP1. The identity of the isolate was established as Brevibacillus sp. based on partial 16S rDNA sequence data from eight single colonies with Gram-positive Brevibacillus choshinensis as the closest match (99.5%). Spotting tests on NA employing spore suspension in aqueous ethanol (0%, 25%, 50%, 60%, 70%, 80% or 90%, v/v) indicated unhindered bacterial-survival in alcohol for 1 month, and that at 2 or 4 months revealed 90% ethanol as more sporicidal than lower levels, corroborated by plating results. Grape microcuttings inoculated with ARBG1 showed substantial general colonization of shoots, roots and medium but low endophytic colonization. CONCLUSIONS: The rare type of spore-producing consistently Gram-negative bacterial isolate ARBG1 was identified as Brevibacillus sp. based on 16S rDNA sequence similarity. The alcohol-defying organism was nonpathogenic and survived in covert form in grape cultures. Aqueous 90% ethanol appeared more sporicidal than lower levels. SIGNIFICANCE AND IMPACT OF THE STUDY: Characterization of an unusual endospore-forming Gram-negative bacterium, observation that some bacteria may fall outside the purview of standard 16S rDNA primers, elucidation of the threats of covert bacteria in plant tissue cultures and alcohol-mediated lateral transmission of spore formers, and the revelation that 70-80% ethanol may not be the most effective bactericidal concentration for all bacteria.

Base Sequence↗

Prion-removal capacity of chromatographic and ethanol precipitation steps used in the production of albumin and immunoglobulins.

BACKGROUND AND OBJECTIVES: Although there is no epidemiological evidence to suggest that classical Creutzfeldt-Jakob disease (CJD) is transmitted through blood or blood products, the variant form (vCJD) has been implicated in transmission via packed red blood cells. The potential threat of the infectious agent contaminating plasma pools has led to manufacturing processes being examined for capacity to remove prions. The objective of these studies was to examine the prion-removal potential of the chromatographic purification and ethanol precipitation steps used to fractionate immunoglobulins and albumin from human plasma. MATERIALS AND METHODS: Western blot assay was used to examine the partitioning of proteinase K-resistant scrapie prion protein (PrPsc) over DEAE Sepharose, CM Sepharose and Macro-Prep High Q chromatographic columns, utilizing microsomal scrapie 263K spiked into each scaled down feedstream and assayed after each chromatographic step. In further studies, bioassay in C57 black mice was used and spikes of 10 000 g clarified brain homogenate of scrapie ME7 were added to feedstreams before sequences of scaled down chromatographic or Cohn fractionation process steps. RESULTS: The microsomal spiking study with Western blot detection demonstrated substantial partitioning of PrPsc away from the target proteins in all ion exchange chromatographic steps examined. The log10 reduction factors (LRF) across DEAE Sepharose and CM Sepharose columns for albumin were > or = 4.0 and > or = 3.0 respectively. The reductions across DEAE Sepharose and Macro-Prep High Q for intravenous immunoglobulin were 3.3 and > or = 4.1 respectively. Bioassay demonstrated LRFs of >or = 5.6 across the combination of DEAE Sepharose and CM Sepharose columns in the albumin process and > or = 5.4 across the combination of DEAE Sepharose and Macro-Prep High Q columns in the intravenous immunoglobulin process. Bioassay studies also demonstrated a LRF of > or = 5.6 for immunoglobulin produced by Cohn fractionation. CONCLUSIONS: Using rodent-adapted scrapie as a model, the studies indicated that ion exchange chromatography, as well as Cohn immunoglobulin fractionation have the potential to effectively reduce the load of TSE agents should they be present in plasma pools.

Animals↗

Established diabetic neuropathy seems irreversible despite improvements in metabolic and vascular risk markers--a retrospective case-control study in a hospital patient cohort.

AIMS: To gain insight into the natural history of diabetic peripheral neuropathy (DPN) and its risk factors by means of sequential quantitative testing in a hospital patient cohort. METHODS: A retrospective case-control study involving 300 diabetic patients (100 subjects with neuropathy and 200 control subjects) attending Poole Hospital diabetes clinic between 1995 and 2002. All subjects had a detailed annual clinic assessment including vibration perception threshold (VPT) and physical and metabolic assessments and were categorized according to neuropathy status. Established neuropathy was defined as a VPT > 25 V. Cross-sectional data were analysed by means of a t-test and longitudinal data by means of ANOVA. RESULTS: VPTs increased over time in neuropathy patients, with no change in control patients (P < 0.001). Glycaemic control was better over that period in control patients but the rate of improvement in HbA1c over time was similar in both groups. Triglyceride and high-density lipoprotein cholesterol levels improved in both groups, with significantly greater change in the control group. CONCLUSIONS: Data on reversibility of neuropathy are scarce and our 8-year series shows a continual deterioration in VPT in patients with a threshold > 25 V despite modest improvements in glycaemic control and lipid parameters. This work also supports a vascular association with neuropathy and identifies neuropathic patients as a high-risk cardiovascular group in whom, despite little influence on neuropathy itself, the above metabolic factors should be actively addressed.

Adult↗

The international migration of Indian nurses.

AIM: To identify the factors responsible for the international migration of Indian nurses. METHODS: The paper is based on the responses of 448 nurse practitioners, nurse educators and nurse administrators to a questionnaire administered to them in December 2004-January 2005. Key factors were identified by the analysis of contingency tables. DISCUSSION: Apart from economic factors, dissatisfaction with working conditions and unhappiness with prevalent social attitudes towards nurses were identified as being of crucial importance for the international migration of Indian nurses. It was found that nurses working in the private sector and from some linguistic and religious groups were particularly prone to migration. Nurses working in the government sector seemed to be more worried about being unable to adjust to working conditions abroad, and therefore less keen to migrate. The fact that they enjoyed better pay scales, a more relaxed work atmosphere and more facilities may have also played a part here. What seemed to be vital to the decision to migrate for a large number of government sector nurses belonging to the so-called 'Forward' and 'Middle' Castes was that they were being crowded out of promotional avenues as a result of the government's policy of Reservations in Promotions for Scheduled Castes and Tribes. CONCLUSION: Health policy-makers in India need to take a serious look at the growing migration of nurses to foreign countries. While such migration leads to inflow of foreign exchange, it also implies the loss of medical personnel vital for the fulfilment of national goals.

Adult↗

Photodynamic action of red light for treatment of erythrasma: preliminary results.

BACKGROUND: Erythrasma is a superficial cutaneous infection caused by Corynebacterium minutissimum and is characterized by fluorescence under Wood's light (UV) because of the presence of porphyrins. These molecules are photosensitizing and we propose to assess efficacy of red light that activates porphyrins (photodynamic reaction) in treatment of this pathology. OBJECTIVES: Assessment of effects of photodynamic action of red light for treatment of erythrasma without exogenous photosensitizing molecules. METHODS: Thirteen patients with erythrasma were treated by one illumination (80 J/cm2) by red light (broad band, peak at 635 nm) without exogenous photosensitizing molecules. Disappearance or reduction of extent of lesions were observed 2 weeks later. If lesions were still present, a second irradiation was conducted with the same method. RESULTS: Preliminary results are presented. As a result of red light irradiation, we noticed a complete recovery for three patients and, in most other cases, reduction of extent of lesions (mean: -29% after one session). The treatment was well tolerated. CONCLUSION: We report first cases of photodynamic treatment of erythrasma. There are other reports of clinical applications of antimicrobial action of photodynamic therapy in dermatology (acne vulgaris, leishmaniasis, warts, etc.). But there are few applications without addition of exogenous photosensitizing agent. The originality and interest of our study is to use spontaneous presence of porphyrins in the lesions. This technique seems to be an interesting alternative, inexpensive and easy, for the treatment of this localized infection. But an optimal method is still to be determined to improve efficacy.

Adult↗

Whiplash associated disorder: incidence and natural history over the first month for patients presenting to a UK emergency department.

OBJECTIVES: To describe the epidemiology, process of care, and outcomes at 4-6 weeks after injury among patients with whiplash associated disorder attending a UK emergency department. METHODS: All patients presenting during the study period with neck pain following a road traffic accident who met the inclusion criteria were assessed. Patients were followed up with a telephone interview at 4-6 weeks after attendance using the Neck Disability Index (NDI). The patient's general practitioner (GP) was contacted post attendance to ascertain subsequent healthcare use. RESULTS: A total of 200 patients were recruited to the study, of which 30 were lost to follow up. Four variables, midline tenderness (p = 0.008; 95% CI 0.9 to 6.1), x ray request (p = 0.004; 0.9 to 6.1), wearing a seat belt (p = 0.038; 0.2 to 6.2), and having seen their GP post injury (p = 0.001; CI -10.5 to 6.6), were found to be associated with a higher NDI score at follow up. Significant correlation was identified with a high pain score and an increasing age of patient and high NDI scores. No correlation was found between the impact speed, speed of vehicle struck, or time since incident with the NDI. Two thirds of patients had some disability at 4-6 weeks after injury; 91 patients (54.5%) saw their GP in the intervening period between attending the department and telephone follow up, and 87/170 patients had no idea about their prognosis. CONCLUSIONS: This study identifies that there is significant disability associated with whiplash associated disorder. Clear prognostic information would be a useful development.

Accidents, Traffic↗

Evidence of breed-dependent differences in susceptibility to porcine circovirus type-2-associated disease and lesions.

Porcine circovirus type 2 (PCV2) has been confirmed as the primary cause of postweaning multisystemic wasting syndrome (PMWS). However, in the field, PMWS is seen only in a small percentage of pigs infected with PCV2. The overall objective of the study reported here was to determine whether host genetic differences in the susceptibility to PCV2-associated disease exist among selected breeds of pigs. This study included Duroc (n = 23), Landrace (n = 19), and Large White (n = 21) pigs. The pigs were infected intranasally and intramuscularly at 5-7 weeks of age with PCV2. A portion of the pigs (31/63; 30.2%) had low passively acquired PCV2 antibodies at the time of infection. There were no differences in mean weight gain, rectal temperature, or respiratory score. Clinical disease compatible with PMWS was observed only in the Landrace pigs. Most of the PCV2-infected pigs had enlarged lymph nodes, and individual Duroc and Landrace pigs had mottled tan lungs. PCV2-associated lymphoid depletion and granulomatous inflammation were observed in pigs of all breeds. Three of 19 Landrace pigs and none of the Duroc or Large White pigs developed severe lymphoid lesions associated with large amounts of intralesional PCV2 antigen typical of PMWS. Compared with seronegative Landrace pigs, Landrace pigs that had low maternal antibodies at the time of PCV2 inoculation had significantly (P < 0.05) less-severe PCV2-associated lesions. The results suggest a predisposition of the Landrace pigs of this study to PCV2-induced disease and lesions, and that low levels of passively acquired antibodies are protective.

Animals↗