Plasma concentrations and sedative effects of a dexmedetomidine, midazolam, and butorphanol combination after transnasal administration in healthy rabbits.

Plasma concentrations of dexmedetomidine (D = 0.1 mg/kg), midazolam (M = 2 mg/kg), and butorphanol (B = 0.4 mg/kg) were analyzed by liquid chromatography-mass spectrometry (LC-MS/MS) after their simultaneous (DMB) transnasal (TN) administration to healthy rabbits. Time-dependent changes in sedation and antinociception were evaluated by measuring a sedation score based on rabbit's posture, loss of the righting, palpebral and pedal withdrawal reflexes and by instrumental monitoring of rectal temperature, heart rate, arterial blood pressure, pulse-oximetry, and capnometry. The peak plasma concentration (Cmax ) of each drug was reached within 5 min (Tmax ) from DMB-TN administration along with deep sedation and analgesia. Such effects subsided after 45 min into a moderate sedation and analgesia lasting for additional 15 min. All rabbits awakened spontaneously and uneventfully 90 min after DMB-TN administration. During the anesthetic procedure, arterial blood pressure markedly decreased and respiratory depression ensued requiring oxygen supplementation. The results of this study show that all three molecules of the DMB combination were absorbed through the TN route, inducing deep sedation and analgesia suitable for minor surgical procedures. Such combination should be used with caution in rabbits bearing cardiovascular or respiratory diseases because of its ability to induce hypotension and respiratory depression.

Gastrointestinal autonomic nerve tumor of the jejunum. Case report and review of the literature.

Gastrointestinal autonomic nerve tumor is very rare and it is difficult to distinguish this tumor from other gastrointestinal tumors due to the absence of clinical, instrumental and macroscopic features which allow pre- or intraoperative diagnosis. Our aim was to recognize the characteristic features (preoperative, intraoperative, pathological) that would allow diagnosis of gastrointestinal autonomic nerve tumor. A case of gastrointestinal autonomic nerve tumor of the jejunum is reported. Surgical specimen was routinely processed. Immunohistochemical staining was performed according to modified immunoperoxidase Avidin-Biotin-Peroxidase Complex method. An electron microscopy study was also performed. The tumor mass showed some characteristic pathological findings: histologically, it was composed of spindle cells and epithelioid cells; immunohistochemically, a focal positivity for Neuron Specific Enolase was shown, and finally, ultrastructural examination showed neuron-like cells with long cytoplasmic processes containing microtubules and bulbouns synapse-like structures with dense core neurosecretory-type granules. Preoperatively gastrointestinal autonomic nerve tumor of the jejunum must be considered and treated as a malignant tumor. A correct diagnosis is possible only with immunohistochemical and ultrastructural studies. It is probable that this tumor is more common than previously thought.

Olfactory transduction mechanisms in sheep.

The enzyme adenylyl cyclase from sheep olfactory epithelium is dually regulated by GTP and is highly sensitive to the nucleotide analogues GTP gamma S and GppNHp, as well as to fluoride ions and forskolin. Many, but not all, odorants tested are able to stimulate adenylyl cyclase in a dose-dependent manner and with different potencies. Such an effect is detectable only in the presence of GTP. The odorants belonging to the putrid class are the least effective in stimulating adenylyl cyclase activity, and only furfuryl mercaptan significantly increases cAMP biosynthesis. Mixtures of two odorants, chosen among those able to activate adenylyl cyclase, induce additive or supra-additive effects, suggesting the presence of many different receptor types. The presence of an alternative olfactory signal transduction process, i.e. the inositol phospholipid second messenger system, has been evaluated. Triethylamine, a putrid odorant completely ineffective on cAMP levels, is able to significantly increase inositol phosphate accumulation, indicating the coexistence of both cAMP- and InsP3-mediated signalling pathways in sheep olfactory epithelium.

[Biological and surgical aspects of the use of polymers in experimental surgery. 1: implants on the oculo-extrinsic musculature]. / Aspetti biologici e chirurgici dell'impiego di un polimero nella chirurgia sperimentale. Nota 1:protesi della muscolatura oculo-estrinseca.

Composite sheets obtained reinforcing PHEMA with a tricot PET net have been implanted in rabbits to test their potential applications for cross-eye surgical correction. The mechanical characterization of the composites has been carried out both in static tension and fatigue. The clinical evaluation was performed on twelve adult New Zealand white Rabbits implanting the sheets on the rectus dorsalis muscle of the eye. The material seems to be highly compatible with the surrounding tissue, mechanical satisfying and clinically helpful in correcting many of the pathological conditions connected with strabismus. The long term behaviour of the implanted prosthesis in still under investigation.

[Initial observations on the biocompatibility of a polymer used as a skin dressing]. / Prime osservazioni sulla biocompatibilita' di un polimero utilizzabile quale protesi cutanea.

In the development of a dressing for burn wound covers, a material is required which combines good oxygen permeability, high water content and good biocompatibility with reasonable mechanical properties. One of the most important functions of the cover is to protect the burned surfaces from drying out and to constitute the first defence against microbial invasion. In this study composite sheets crosslinked either in presence of glicerol or diacetin, obtained by reinforcing PHEMA with a tricot PET net have been implanted subacute in rabbits, to test their biocompatibility. The same composites crosslinked in presence of diacetin and grafted on a polybutadene film, have been used as a skin graft on rabbits.