Modified submental intubation techniques for maxillofacial surgery - A report of five cases.

BACKGROUND: Submental intubation has been the recommended airway management procedure for maxillofacial surgery since proposed by Altemir in 1986. We adopted various submental intubation modifications based on modified intubation protocols and report on the effectiveness and problems of each modified method. CASE: Among a total of 13 submental intubation cases during the last five years, five representative methods are described. The proximal end of the endotracheal tube was protected by a nelaton catheter in case 1, by a suction connector in case 2, and by a dental needle cap in case 3. In case 4, a nasal speculum was used to expand a single route, and in case 5, a laparoscopic trocar was used to secure a single route. CONCLUSIONS: Use of a laparoscopic trocar might be the most effective way to obtain a single submental route. However, considering cost, use of a nasal speculum is also an effective suboptimal solution.

Arginase II activity regulates cytosolic Ca2+ level in a p32-dependent manner that contributes to Ca2+-dependent vasoconstriction in native low-density lipoprotein-stimulated vascular smooth muscle cells.

Although arginase II (ArgII) is abundant in mitochondria, Ca2+-accumulating organelles, the relationship between ArgII activity and Ca2+ translocation into mitochondria and the regulation of cytosolic Ca2+ signaling are completely unknown. We investigated the effects of ArgII activity on mitochondrial Ca2+ uptake through mitochondrial p32 protein (p32m) and on CaMKII-dependent vascular smooth muscle cell (VSMC) contraction. Native low-density lipoprotein stimulation induced an increase in [Ca2+]m as measured by CoCl2-quenched calcein-AM fluorescence, which was prevented by Arg inhibition in hAoSMCs and reduced in mAoSMCs from ArgII-/- mice. Conversely, [Ca2+]c analyzed with Fluo-4 AM was increased by Arg inhibition and ArgII gene knockout. The increased [Ca2+]c resulted in CaMKII and MLC 20 phosphorylation, which was associated with enhanced vasoconstriction activity to phenylephrine (PE) in the vascular tension assay. Cy5-tagged siRNA against mitochondrial p32 mRNA (sip32m) abolished mitochondrial Ca2+ uptake and induced activation of CaMKII. Spermine, a polyamine, induced mitochondrial Ca2+ uptake and dephosphorylation of CaMKII and was completely inhibited by sip32m incubation. In mAoSMCs from ApoE-null mice fed a high-cholesterol diet (ApoE-/- +HCD), Arg activity was increased, and spermine concentration was higher than that of wild-type mice. Furthermore, [Ca2+]m and p32m levels were elevated, and CaMKII phosphorylation was reduced in mAoSMCs from ApoE-/- +HCD. In vascular tension experiments, an attenuated response to vasoconstrictors in de-endothelialized aorta from ApoE-/- +HCD was recovered by incubation of sip32m. ArgII activity-dependent production of spermine augments Ca2+ transition from the cytosol to the mitochondria in a p32m-dependent manner and regulates CaMKII-dependent constriction in VSMCs.

Resveratrol is an arginase inhibitor contributing to vascular smooth muscle cell vasoconstriction via increasing cytosolic calcium.

The contractility of vascular smooth muscle cells (VSMCs) controls the lumen diameter of vessels, thus serving a role in regulating blood pressure and organ blood flow. Although arginases are known to have numerous effects in the biological activities of VSMCs, the effects of arginase II on the constriction of VSMCs has not yet been investigated. When conducting a natural products screen for an inhibitor against arginase, the present study identified that a relatively high concentration of resveratrol (RSV) exhibited arginase inhibitory activity. Therefore, the present study investigated whether RSV could regulate VSMCs contractions and the underlying mechanism. Arginase inhibition by RSV led to an increase in the concentration of the substrate L­Arg and an accompanying increase in the cytosol Ca2+ concentration [(Ca2+)c] in VSMCs. The increased [Ca2+]c induced by RSV and L­Arg treatments resulted in CaMKII­dependent MLC20 phosphorylation. The effects of RSV on VSMCs were maintained even when VSMCs were pre­treated with sirtinol, an inhibitor of Sirt proteins. In a vascular tension assay with de­endothelialized aortic vessels, vasoconstrictor responses, which were measured using phenylephrine (PE), were significantly enhanced in the RSV­ and L­Arg­treated vessels. Therefore, although arginase inhibition has exhibited beneficial effects in various diseases, care is required when considering administration of an arginase inhibitor to patients with vessels endothelial dysfunction as RSV can induce vessel contraction.