Pituitary adenylate cyclase-activating peptide receptor 1 mediates anti-inflammatory effects in allergic airway inflammation in mice.

BACKGROUND: Bronchial asthma is characterized by airway inflammation and reversible obstruction. Since the gold standard of therapy, a combination of anti-inflammatory corticosteroids and bronchodilatory ß(2) agonists, has recently been discussed to be related to an increased mortality, there is a need for novel therapeutic pathways. OBJECTIVE: A new experimental concept that encompasses the vasoactive intestinal peptide/pituitary adenylate cyclase activating peptide (PACAP) family of receptors by demonstrating the anti-inflammatory effects of the PACAP receptor 1 (PAC1R) in a murine model of allergic asthma is described. METHODS: PAC1R expression was investigated in lung tissue and isolated dendritic cells (DCs) via real-time PCR. Ovalbumin (OVA)-induced asthma models were used in PAC1R-deficient mice and BALB/c mice treated with PAC1R agonist maxadilan (MAX). Bronchoalveolar lavages have been performed and investigated at the cellular and cytokine levels. Fluorescence staining of a frozen lung section has been performed to detect eosinophil granulocytes in lung tissue. Plasma IgE levels have been quantified via the ELISA technique. Lung function was determined using head-out body plethysmography or whole-body plethysmography. RESULTS: Increased PAC1R mRNA expression in lung tissue was present under inflammatory conditions. PAC1R expression was detected on DCs. In OVA-induced asthma models, which were applied to PAC1R-deficient mice (PAC1R(-/-)) and to BALB/c mice treated with the specific PAC1R agonist MAX, PAC1R deficiency resulted in inflammatory effects, while agonistic stimulation resulted in anti-inflammatory effects. No effects on lung function were detected both in the gene-depletion and in the pharmacologic studies. In summary, here, we demonstrate that anti-inflammatory effects can be achieved via PAC1R. CONCLUSION: PAC1R agonists may represent a promising target for an anti-inflammatory therapy in airway diseases such as bronchial asthma.

A toxicological evaluation of inhaled solid lipid nanoparticles used as a potential drug delivery system for the lung.

Inhalation is a non-invasive approach for both local and systemic drug delivery. This study aimed to define the therapeutic window for solid lipid nanoparticles (SLNs) as a drug delivery system by inhalation from a toxicological point of view. To estimate the toxic dose of SLNs in vitro, A549 cells and murine precision-cut lung slices (PCLS) were exposed to increasing concentrations of SLNs. The cytotoxic effect of SLNs on A549 cells was evaluated by MTT and NRU assays. Viability of lung tissue was determined with WST assay and by life/dead staining using calcein AM/EthD-1 for confocal microscopy (CLSM) followed by quantitative analysis with IMARIS. Inflammation was assessed by measuring chemokine KC and TNF-alpha levels. The in vivo effects were determined in a 16-day repeated-dose inhalation toxicity study using female BALB/c mice, which were daily exposed to different concentrations of SLN30 aerosols (1-200 microg deposit dose). Local inflammatory effects in the respiratory tract were evaluated by determination of total protein content, LDH, chemokine KC, IL-6, and differential cell counts, performed on days 4, 8, 12, and 16 in bronchoalveolar lavage fluid. Additionally, a histopathological evaluation of toxicologically relevant organs was accomplished. The in vitro and ex vivo dose finding experiments showed toxic effects beginning at concentrations of about 500 microg/ml. Therefore, we used 1-200 microg deposit doses/animal for the in vivo experiments. Even after 16 days of challenge with a 200-microg deposit dose, SLNs induced no significant signs of inflammation. We observed no consistent increase in LDH release, protein levels, or other signs of inflammation such as chemokine KC, IL-6, or neutrophilia. In contrast, the particle control (carbon black) caused inflammatory and cytotoxic effects at corresponding concentrations. These results confirm that repeated inhalation exposure to SLN30 at concentrations lower than a 200-microg deposit dose is safe in a murine inhalation model.

Haemodynamic and blood gas changes in buffaloes (Bubalus bubalis) in the supine position following thiopentone anaesthesia with premedication.

Studies were undertaken on seven adult female buffaloes (Bubalus bubalis) premedicated with triflupromazine hydrochloride (0.3 mg/kg) and chloral hydrate (30 mg/kg). Anaesthesia was induced with thiopentone sodium (10 mg/kg) and animals were kept under intermittent positive pressure ventilation. Measurements were made for 30 min in the lateral position, for 20 min in the supine position and subsequently for 40 min again in the lateral position. Regurgitation during anaesthesia was avoided by evacuation of the rumen by rumenotomy two days prior to the experiment. When animals were in the lateral position there were minimal changes in arterial pressure and heart rate but central venous pressure rose. These changes were related to intermittent positive pressure ventilation. In the supine position, increase in heart rate (28%) was associated with profound hypotension (56%) and decrease in central venous pressure (171%) in these animals. There was a fall in venous oxygen tension and a marked increase (91%) in oxygen extraction ratio. Restoration to the lateral position ameliorated all these changes rapidly. It was suggested that a 'low pressure-low flow' circulatory state exists in anaesthetised adult buffaloes in the supine position.

An outbreak of tropical theileriosis in cattle in Afghanistan.

An outbreak of tropical theileriosis (T. annulata infection) is reported in artificial insemination Holstein bulls in Kabul (Afghanistan). The diagnostic work at the Central Veterinary Diagnostic Laboratory is described and the treatment given and results obtained by the Kabul Animal Health Clinic are reported. This case report constitutes the first account of the disease in Afghanistan where diagnostic confirmation has been made from material sent to internatinational reference centres.