Evaluation of the protection elicited by direct and indirect exposure to live attenuated infectious laryngotracheitis virus vaccines against a recent challenge strain from the United States

In a recent study (Oldoni & García, 2007), some field strains of infectious laryngotracheitis viruses (ILTV) were characterized as genotypically different (group VI) from ILT vaccine strains. The objective of this study was to evaluate the protection elicited by one chicken embryo origin (CEO) and one tissue culture origin (TCO) vaccine against a field isolate from group VI after direct and indirect exposure to ILTV live attenuated vaccines. In phase 1 of the experiment, non-vaccinated chickens were placed into contact with the eye drop vaccinates for a period of four weeks after vaccination. Transmission of the vaccine virus to these in-contact birds was demonstrated by real time PCR and antibody production, although the in-contact birds did not become protected against disease when subsequently challenged in phase 2 of the experiment. This emphasized the importance of uniform vaccination to obtain adequate protection, both to avoid the occurrence of susceptible chickens, and to minimize the potential for reversion to virulence of live-attenuated vaccines. In phase 2, protection against challenge with a group VI field virus was assessed four weeks after vaccination by scoring clinical signs and mortality, and quantifying weight gain. Sentinel birds were added to the groups one day after challenge to assess shedding of challenge virus, using real time PCR and virus isolation, during the period 2 to 12 days post challenge. The results showed that the CEO and TCO eye drop-vaccinated chickens were protected against challenge with the group VI virus, even though it was genetically different from the vaccine strains, and that challenge virus was not transmitted from these protected birds to the sentinels.     

Our experience with diagnostics of congenital disorders of glycosylation

The aim of this study is to report our 3years experience with the screening of congenital disorders of glycosylation. A common isoelectric focusing method with immunofixation was used for analysis of serum transferrin and alpha1-antitrypsin, apart from several other procedures. A group of about 1000 individuals, both healthy controls and patients, mostly with signs of a metabolic disease were examined. Here we present an overview of (1) hypoglycosylation findings, (2) distribution of protein variants, (3) misguiding rare Tf variants found in our set, and (4) association of some phenotypes with various diseases.     

Predominant pathogenic role of tumor necrosis factor in experimental colitis in mice

Antibodies to tumor necrosis factor (TNF)-α have been recently proposed as effective treatment for patients with Crohn's disease. Here, we analyze the functional role of TNF-α in a mouse model of chronic intestinal inflammation induced by the hapten reagent 2,4,6,-trinitrobenzene sulfonic acid (TNBS) that mimics some characteristics of Crohn's disease in humans. Macrophage-enriched lamina propria (LP) mononuclear cells from mice with TNBS-induced colitis produced 10–30-fold higher levels of TNF-α mRNA and protein than cells from control mice. When mice with chronic colitis were treated by intraperitoneal injection of antibodies to TNF-α, an improvement of both the clinical and histopathologic signs of disease was found. Isolated macrophage-enriched LP cells from anti-TNF-α-treated mice produced strikingly less pro-inflammatory cytokines such as interleukin (IL)-1 and IL-6 in cell culture. The predominant role of TNF-α in the mouse TNBS-induced colitis model was further underlined by the finding that striking colonic inflammation and lethal pancolitis was induced in TNF-α-transgenic mice upon TNBS treatment. Conversely, no significant TNBS-induced colitis could be induced in mice in which the TNF-α gene had been inactivated by homologous recombination. Complementation of TNF-α function in TNF^?/? mice by the expression of a mouse TNF-α transgene was sufficient to reverse this effect. Taken together, the data provide direct evidence for a predominant role of TNF-α in a mouse model of chronic intestinal inflammation and encourage further clinical trials with antibodies to TNF-α for the treatment of patients with Crohn's disease.     

Long-Term Antibody Response and Vaccination Efficacy in Patients with COVID-19: A Single Center One-Year Prospective Study from the Czech Republic

Background: The diagnosis of SARS-CoV-2 is almost exclusively performed by PCR or antigen detection. The detection of specific antibodies has not yet been considered in official diagnostic guidelines as major laboratory evidence for a case definition. The aim the present study is to analyze antibody responses in outpatient and inpatient cohorts of COVID-19 patients in the Czech Republic over a 12-month period, and assess the potential of antibodies as a diagnostic tool. Methods: A total of 644 patients was enrolled in the prospective study. IgA, IgM and IgG antibody levels, as well as virus neutralization titers, were analyzed over a 12-month period. Results: Our study showed low antibody positivity levels at the admission. However, at 2 weeks after infection, 98.75% and 95.00% of hospitalized patients were IgA and IgG positive, respectively. Even in the outpatient cohort characterized by milder disease courses, the IgG antibody response was still sustained at 9 and 12 months. The data show a high correlation between the IgG levels and virus neutralization titers (VNTs). Samples from later time-points showed positive antibody responses after vaccination in both cohorts characterized by high IgG levels and VNT over 1:640. The samples from unvaccinated persons indicated a relatively high level of reinfection at 6.87%. Conclusions: Our results show that the detection of antibodies against the SARS-CoV-2 shows an increasing sensitivity from week 2 after infection and remains highly positive over the 12-month period. The levels of IgG antibodies correlate significantly with the VNTs. This suggests that the serological data may be a valuable tool in the diagnosis of SARS-CoV-2 infection.     

Immunohistochemical detection of cytokeratins in the irradiated mandibular gland of the Wistar rat]

BACKGROUND: Damage to the salivary gland (SG) is a well-known sequela of radiotherapy in humans. In many cases irradiation damage causes xerostomia and problems of speech and swallowing. While the functional restriction and the radiogenic SG tissue damage is well documented using histomorphological, electron microscopic and enzyme histochemical methods, immunohistochemical analyses (IH) of the profile of cytokeratins (CK), epithelial differentiation markers, and their alterations in irradiated glands are rare. METHODS: In 59 mandibular glands of rats, we investigated the distribution of CK by IH. The animals differed in age from 3 months to 2 years and pretreatment status (irradiation versus no irradiation). The IH were performed at selected time points (< 4 months/> or = 4-6 months/> 6 months). RESULTS: The monoclonal antibodies (E3, Ks13.1, NCL5D3, K8.12; against CK 17, CK 13, CK 8 and CK 13/15/16, respectively) identified different epithelial structures in rat SG tissue, including excretory duct cells (ECD), striated duct cells (SD), granular convoluted tubules (GTC), intercalated duct cells (ICD), and myoepithelial cells (MC). As typical results, E3 usually stained the ICD, SD, and ECD moderately to strongly and stained the GTC in trace amounts or slightly. K8.12 staining was restricted to ECD and MC. Differences in immunoreactivity were seen between irradiated and non-irradiated glands, predominantly with stronger staining in the irradiated group. A conspicuous finding was the stronger expression of CK 13 in irradiated ECD, ICD, and SD within a latency period of 4-6 months. A similar finding was demonstrated in ICD, ECD, and SD cells after incubation with CK 17 antibodies. In both instances, the staining profile of irradiated glands did not return to nontreatment levels in the long term after exposure. CONCLUSIONS: Previous irradiation has to be considered when interpreting IH of salivary gland tissue, especially in studies on chronic degenerative diseases of the salivary glands.     

Inaccessible information is useless information: addressing the knowledge gap

The burdens of increasing information overload, time constraints, and the high human and financial costs of medical error, mean that doctors cannot practice high quality evidence-based medicine without the aid of decision support systems at the point of care. The physician's role is to formulate a management plan based on clinical judgment, the patient's unique circumstances and preferences, and the best available evidence. Clineguide is a clinical knowledge system that will integrate into the workflow to improve patient outcomes, reduce variability of care, and promote efficiency in the health care process. This article discusses some of the issues surrounding the provision of rapid, accurate, and accessible information to health care professionals.