Active immunisation of lambs with a monoclonal antibody against clenbuterol

An experiment was undertaken with 50 Texel x Suffolk-Cheviot lambs (54+/-8.8 days of age) to investigate the effects of active immunisation with a murine monoclonal antibody against clenburerol on growth and carcass characteristics. Animals on treatments 1 and 2 each received 0.1 mg of clenbuterol antibody while animals on treatments 3 and 4 received 0.1 mg of antibody encapsulated within a synthetic polymer. Diethylaminoethyl (DEAE)-dextran was used as the adjuvant in treatments 1 and 3 and saponin in treatments 2 and 4. Control animals were immunised with saponin only. Four immunisations were given at 4-week intervals. Animals were slaughtered 3 weeks after the final immunisation. Each vaccine evoked a similar level of antibody response while the control group showed no titres. Lamb growth rate did not vary significantly between the vaccinated and control groups. Dressing proportion was higher (P

Human Papillomavirus (HPV): Making the case for “Immunisation for All”

Human Papillomavirus (HPV) contributes to the most common sexually transmitted infections, with repeated and persistent infection with particular types causing disease in both men and women. Infection with low-risk HPV types can lead to genital warts and benign lesions of the oral cavity, while high-risk types can cause various HPV-related malignancies. The incidence of head and neck cancer has been rising in the past number of decades mostly due to oropharyngeal cancer linked to HPV infection. HPV vaccination has been shown to be effective for cervical and other anogenital HPV-related cancers, and there is significant potential for HPV vaccination to prevent oropharyngeal cancers, given that the HPV types implicated in this disease can be protected against by the HPV vaccine. Few countries have implemented a universal HPV vaccination programme for males and females, with many countries arguing that female only vaccination programmes protect males via herd immunity, and that men-who-have-sex-with-men will be protected via targeted vaccination programmes. We argue these may be limited in their effectiveness. We propose that the most effective, practical, ethical and potentially cost effective solution is universal HPV vaccination that might lead to control of HPV-related diseases in men and women alike.

The production and characterisation of dinitrocarbanilide antibodies raised using antigen mimics.

Polyclonal antibodies were produced to detect the coccidiostat nicarbazin. Due to structural constraints of the active component of nicarbazin, dinitrocarbanilide (DNC), three different compounds that shared a common substructure with DNC were used as antigen mimics. The compounds (N-suceinyl-L-alanyl-L-alanyl-L-alanine 4-nitroanilide (SAN), L-glutamic acid gamma-(p-nitroanilide) (GAN) and p-nitrosuccinanilic acid (NSA)) were conjugated to a carrier protein and used in the immunisation of rabbits. Five different polyclonal sera were produced and consequently characterised. The antibodies exhibited an IC50 range of 2.3-7.6 ng/ml using a competitive ELISA procedure, Serum from one rabbit, R555, exhibited an IC50 of 2.9 ng/ml for DNC and cross-reactivity studies showed that this serum was specific for DNC and did not cross-react with other coccidiostats such as halofuginone, toltrazuril or ronidazole. (C) 2002 Elsevier Science B.V. All rights reserved.

The production and characterisation of an antibody to detect the coccidiostat toltrazuril and its metabolite ponazuril.

The production of an antibody to detect toltrazuril or its metabolite ponazuril is complicated due to structural constraints of conjugating these coccidiostats to a carrier protein. Therefore a search was carried out for a compound that shared a common substructure to use as an antigen mimic. The chosen compound, trifluoraminoether, was conjugated to two carrier proteins (HSA and BTG) and used in the immunisation of six rabbits. Two immunogen doses (1 mg and 0.1 mg) were also used. All six rabbits produced an immunological response to the hapten regardless of the carrier protein or immunogen dose used. The most sensitive polyclonal antibody produced, designated R609, was subsequently characterised. This antiserum exhibited an IC50 of 18 ng ml-1 using a competitive ELISA format. Cross reactivity studies show that this serum is specific for toltrazuril and its metabolites (toltrazuril sulfoxide and toltrazuril sulfone) but does not cross-react with other coccidiostats such as halofuginone, nitroimidazoles or nicarbazin. This is the first reported production of an antibody capable of specifically binding toltrazuril and ponazuril.

PREVENTION OF INFECTION AFTER SPLENECTOMY - WHAT PRECAUTIONS ARE REQUIRED

Removal of the spleen presents a lifelong risk of infection, in particular the syndrome of overwhelming postsplenectomy sepsis. Streptococcus pneumoniae, Haemophilus influenzae and Neisseria meningitides are the most common organisms involved, but malaria, babesiosis and DF-2 also create a problem. Immunisation with pneumococcal vaccine, H. influenzae type b vaccine, influenza vaccine and, if in a high risk area, meningococcal vaccine is recommended. Lifelong phenoxymethylpenicillin 250mg twice daily is also advised, especially in high risk groups such as children and immunocompromised patients. If patients are unwilling to take medicine lifelong, or are unlikely to comply, an antibiotic supply should be made available at all times and administration should commence at the first sign of illness.

Developmental changes in pain expression in premature, full-term, two- and four-month-old infants

The purpose of this study was to examine the behavioural responses of infants to pain stimuli across different developmental ages. Eighty infants were included in this cross-sectional design. Four subsamples of 20 infants each included: (1) premature infants between 32 and 34 weeks gestational age undergoing heel-stick procedure; (2) full-term infants receiving intramuscular vitamin K injection; (3) 2-month-old infants receiving subcutaneous injection for immunisation against DPT; and (4) 4-month-old infants receiving subcutaneous injection for immunisation against DPT. Audio and video recordings were made for 15 sec from stimulus. Cry analysis was conducted on the first full expiratory cry by FFT with time and frequency measures. Facial action was coded using the Neonatal Facial Action Coding System (NFCS). Results from multivariate analysis showed that premature infants were different from older infants, that full-term newborns were different from others, but that 2- and 4-month-olds were similar. The specific variables contributing to the significance were higher pitched cries and more horizontal mouth stretch in the premature group and more taut tongue in the full-term newborns. The results imply that the premature infant has the basis for communicating pain via facial actions but that these are not well developed. The full-term newborn is better equipped to interact with his caretakers and express his distress through specific facial actions. The cries of the premature infant, however, have more of the characteristics that are arousing to the listener which serve to alert the caregiver of the state of distress from pain.

Local and systemic immune responses in mice to intranasal delivery of peptides representing bovine respiratory syncytial virus epitopes encapsulated in poly (dl-lactide-co-glycolide) microparticles

The potential of a microparticulate vaccine delivery system in eliciting a specific mucosal antibody response in the respiratory tract of mice was evaluated. Two vaccine candidate peptides representing epitopes from the G attachment and F fusion antigens from bovine respiratory syncytial virus (BRSV) were encapsulated into poly(dl- lactide co-glycolide) biodegradable microparticles. The encapsulation process did not denature the entrapped peptides as verified by detection of peptide-specific antibodies in mucosal secretions by ELISA using peptide as antigen. Following intranasal immunisation, the encapsulated peptides induced stronger upper and lower respiratory tract specific-IgA responses, respectively, than the soluble peptide forms. Moreover, a strong peptide-specific cell-mediated immune response was measured in splenocytes in vitro from the mice inoculated with the encapsulated peptides compared to their soluble form alone indicating that migration of primed T cells had taken place from the site of mucosal stimulation in the upper respiratory tract to the spleen. These results act as a foundation for vaccine efficacy studies in large animal BRSV challenge models.

Fasciola hepatica:studies on vaccination of rats and mice with a surface antigen prepared from fluke homogenate by means of a monoclonal antibody

T1 tegumental antigen was isolated from a homogenate of eight- to 10-week-old Fasciola hepatica using a T1-specific monoclonal antibody bound to sepharose in an antibody-affinity column. Rats and mice were vaccinated with T1 antigen in Freund's complete adjuvant, and control groups received equivalent amounts of non-T1 antigen (eluted from the antibody-affinity column) or ovalbumin. On completion of the immunisation programme, serum samples were collected for ELISA and IFA testing. The animals were challenged by oral infection with F hepatica metacercariae or, for several vaccinated rats, by intraperitoneal transplantation of live adult flukes. At autopsy, worm-burden and liver damage was assessed for each animal and the condition of transplanted flukes was examined. Comparison of test and control groups of animals showed that neither T1 nor non-T1 antigens provided significant protection against challenge, although specific antibody responses against the appropriate sensitising antigen were engendered. Flukes transplanted to the peritoneal cavity of immunised rats survived without damage, although they became encased in hollow fibrous capsules of host origin. The results lend support to the pre-existing concept that glycocalyx turnover by discharge of T1 secretory bodies at the apical surface of migrating flukes provides an efficient means of protection for the parasite against host immunity.

Immunogenetic responses in calves to intranasal delivery of bovine respiratory syncytial virus (BRSV) epitopes encapsulated in poly (DL-lactide-co-glycolide) microparticles

Bovine respiratory syncytial virus (BRSV) is the principal aetiological agent of the bovine respiratory disease complex. A BRSV subunit vaccine candidate consisting of two synthetic peptides representing putative protective epitopes on BRSV surface glycoproteins in soluble form or encapsulated in poly(lactide-co-glycolide) (PLG) microparticles were prepared. Calves (10 weeks old) with diminishing levels of BRSV-specific maternal antibody were intranasally administered a single dose of the different peptide formulations. Peptide-specific local immune responses (nasal secretion IgA), but not systemic humoral (serum IgG) or cellular responses (serum IFN-γ), were generated by all forms of peptide. There was a significant reduction in occurrence of respiratory disease in the animals inoculated with all peptide formulations compared to animals given PBS alone. Furthermore no adverse effects were observed in any of the animals post vaccination. These results suggest that intranasal immunisation with the peptide subunit vaccine does induce an as yet unidentified protective immune response.

Lung consequences in adults born prematurely

Although survival has improved significantly in recent years, prematurity remains a major cause of infant and childhood mortality and morbidity. Preterm births (<37 weeks of gestation) account for 8% of live births representing >50 000 live births each year in the UK. Preterm birth, irrespective of whether babies require neonatal intensive care, is associated with increased respiratory symptoms, partially reversible airflow obstruction and abnormal thoracic imaging in childhood and in young adulthood compared with those born at term. Having failed to reach their optimal peak lung function in early adulthood, there are as yet unsubstantiated concerns of accelerated lung function decline especially if exposed to noxious substances leading to chronic respiratory illness; even if the rate of decline in lung function is normal, the threshold for respiratory symptoms will be crossed early. Few adult respiratory physicians enquire about the neonatal period in their clinical practice. The management of these subjects in adulthood is largely evidence free. They are often labelled as asthmatic although the underlying mechanisms are likely to be very different. Smoking cessation, maintaining physical fitness, annual influenza immunisation and a general healthy lifestyle should be endorsed irrespective of any symptoms. There are a number of clinical and research priorities to maximise the quality of life and lung health in the longer term not least understanding the underlying mechanisms and optimising treatment, rather than extrapolating from other airway diseases.