ATOPIC DERMATITIS: EXPRESSION OF IMMUNOLOGICAL IMBALANCE.

Atopic dermatitis is a chronic relapsing-remitting inflammatory skin condition, characterized by a skin barrier dysfunction resulting in epidermal damage and altered permeability to allergens and microbes. Although pathogenesis of atopic dermatitis is complex and still not fully understood, it has been hypothesized that genetic predisposition, environmental factors, and skin barrier dysfunction are involved. Innate and adaptive immune system has also a pivotal role in the development, maintenance and flare-up of atopic dermatitis. The immune-pathogenesis of atopic dermatitis is determined by the impairment of different T helper cells, of their cytokine secretion profiles as well as of their specific receptor. In this review, we focus on the current knowledge of the etiopathogenetic pathways of atopic dermatitis in relationship to the critical role of the innate and adaptive immune system, providing a unifying view.

ALLERGIC RHINITIS AND ADENOID HYPERTROPHY IN CHILDREN: IS ADENOIDECTOMY ALWAYS REALLY USEFUL?

Allergic rhinitis (AR) and adenoid hypertrophy (AH) are common in children and are often associated with each other. Recent studies have shown improvement of respiratory symptoms and reduction in the adenoid volume after anti-allergic medical therapy (intranasal corticosteroids, antihistamines). The aim of our retrospective study is to evaluate the effectiveness of adenoidectomy on respiratory symptoms in pediatric patients with AR. We recruited 404 pediatric patients with AR, and we divided them into 4 groups (1. intermittent-mild rhinitis; 2. intermittent-moderate/severe rhinitis; 3. persistent-mild rhinitis; 4. persistent-moderate/severe rhinitis), using ARIA classification. For each patient we evaluated: age at onset of AR; family history of allergy; the presence of other allergic diseases; serum total IgE values; skin prick test (SPT) results; presence of AH evaluated by rhino-laringeal fibroscopy; adenoidectomy and its efficacy on respiratory symptoms. Our data show an association between AR and AH: 90 of 404 (22%) children with AR had AH of a degree greater than 2nd. A significant percentage (80%) of children suffering from AR did not present satisfactory benefits from adenoidectomy. They reported persistence or recurrence of rhinitic symptoms after surgery or only partial benefits, especially of recurrent respiratory tract infections and nasal obstruction. The local allergic persistent inflammation on nasal mucosa and adenoid tissue is probably the cause of the unsatisfactory results of adenoidectomy, therefore surgery cannot be the first therapeutic step for these children. It is important to extinguish the local inflammation by medical anti-allergic therapy to obtain improvements of nasal symptoms and to prevent adenoid regrowth.

A simple method of infecting rabbits with Bovine herpesvirus 1 and 5.

This report describes an alternative technique to inoculate rabbits and to reproduce infection by Bovine herpesvirus 1 and 5. First, the nostrils are anaesthetized by aspersion with local anaesthetic. A few seconds later, and after proving the insensitivity of the zone, the rabbits are put on their back legs with their nostrils upwards and the inoculum is introduced slowly into each nostril by using disposable droppers. Clinical signs, viral isolation from nasal swabs, histological lesions found, positive polymerase chain reaction and antibodies production confirm the infection. This very simple and bloodless technique, where the animals are exposed to minor distress, may be useful for evaluating the virulence of BoHV-1 and BoHV-5 strains, to study the establishment of latent virus infection and to test the potential of experimental vaccines or properties of antiviral drugs. It may be also suitable for experimental infection with other respiratory viruses in this animal model.

[Detection of Mycoplasma suis in clinical cases with postweaning multisystemic wasting syndrome in swine]. / Detección de Mycoplasma suis en casos clínicos de síndrome del desmedro multisistémico posdestete en porcinos.

Mycoplasma suis is a swine erythrocyte obligatory parasite. Its presence may result in chronic or acute anaemia in different pig categories. It is considered that the postweaning multisystemic wasting syndrome (PMWS) is caused by porcine circovirus type 2, but some aspects of the pathogenesis remain unknown. PMWS signs are impaired weight gain, anaemia and jaundice in 5 to 12 week-old pigs that suffer from immunosuppression and bacterial co-infections. The pigs with signs of these diseases on three porcine farms were studied. Compatible M. suis forms in blood smears and typical PMWS lesions in tissue cuts were seen. This is the first communication of the clinical association between these two entities.

Rapid diagnosis of pseudorabies virus infection in swine tissues using the polymerase chain reaction (PCR).

In Argentina pseudorabies is an endemic disease. Routine diagnosis is made by virus isolation. It is a very long procedure to carry out and gives variable results depending on the quality of sample, hence the need for effective techniques, which are rapid and not dependent on the isolation of infectious virus. The polymerase chain reaction (PCR) technique has provided a sensitive, specific and rapid mean to detect DNA sequences. This study describes a PCR method for detection of pseudorabies virus sequences in swine tissues. In order to determine the presence of suid herpesvirus-1 DNA and antigens, 36 tissue samples collected from 19 dead pigs, with signs of pseudorabies infection, were examined by PCR, virus isolation and indirect immunofluorescence, respectively. Fifteen out of 19 pigs were positive at least for one tissue by PCR (15/19) while only three pseudorabies virus strains were isolated (3/19). All the amplified products were identified by digestion with Sa/l and hybridization. The method described herein circumvents tedious viral isolation and DNA purification and would be a valuable tool for rapid diagnosis, since it would take less than 5 h to reach an accurate result even in poorly preserved tissue samples.

Rapid diagnosis of pseudorabies virus infection in swine tissues using the polymerase chain reaction (PCR)

In Argentina pseudorabies is an endemic disease. Routine diagnosis is made by virus isolation. It is a very long procedure to carry out and gives variable results depending on the quality of sample, hence the need for effective techniques, which are rapid and not dependent on the isolation of infectious virus. The polymerase chain reaction (PCR) technique has provided a sensitive, specific and rapid mean to detect DNA sequences. This study describes a PCR method for detection of pseudorabies virus sequences in swine tissues. In order to determine the presence of suid herpesvirus-1 DNA and antigens, 36 tissue samples collected from 19 dead pigs, with signs of pseudorabies infection, were examined by PCR, virus isolation and indirect immunofluorescence, respectively. Fifteen out of 19 pigs were positive at least for one tissue by PCR (15/19) while only three pseudorabies virus strains were isolated (3/19). All the amplified products were identified by digestion with Sa/l and hybridization. The method described herein circumvents tedious viral isolation and DNA purification and would be a valuable tool for rapid diagnosis, since it would take less than 5 h to reach an accurate result even in poorly preserved tissue samples.

Restriction endonuclease analysis of BHV-1 and BHV-5 strains isolated in Argentina.

The genomes of 10 bovine herpesvirus 1 and 5 strains isolated in Argentina from 1989 to 1994, recovered from animals showing different clinical signs, and two reference strains (Los Angeles and A663) were compared by restriction endonuclease analysis. Four restriction enzymes, HindIII, BamHI, EcoRI and PstI, were used and analysis of the restriction patterns used to assign the isolate to either the BHV-1.1, BHV-1.2 or BHV-5 genotype. There was a correlationship between restriction pattern and clinical signs in six out of ten Argentinian isolates.