Bilobed flap reconstruction for skin defects after parotid carcinoma surgery.

OBJECTIVE: To analyse the treatment results of bilobed flap reconstruction performed for skin defects after parotid carcinoma surgery. METHOD: Ten patients who underwent bilobed flap reconstruction for skin defects after parotid carcinoma surgery in our hospital, from 2014 to 2020, were retrospectively enrolled. RESULTS: All patients underwent bilobed flap reconstruction for skin defects after parotid carcinoma surgery. The size of the skin defect was 2.7 × 2.2 cm in the smallest dimension and 9.0 × 6.3 cm in the largest dimension. All bilobed flaps except one healed without any problems. One patient developed partial flap necrosis in the retroauricular region, and was treated with skin grafts after removal of the necrotic tissue under local anaesthesia. All bilobed flaps, including the cases in which skin grafts were performed, survived after post-operative radiotherapy or chemotherapy. CONCLUSION: A bilobed flap is a good reconstruction option for skin defects after parotid carcinoma surgery in some cases.

Endoscopic treatment of difficult bile duct stones by using a double-lumen basket for laser lithotripsy--a case series.

Laser lithotripsy is an effective and safe method for difficult common bile duct (CBD) stones. However, radiolucent laser fibers make accurate fragmentation difficult and require continuous visual control or an accessory for effective targeting. The newly developed double-lumen basket may promote effective laser lithotripsy after stone capture. We performed laser lithotripsy using a double-lumen basket in 14 patients with CBD stones refractive to conventional endoscopic treatment, and evaluated the feasibility and efficacy of this procedure. Stones were successfully fragmented in 13 of 14 patients, and 13 patients eventually became stone-free. Mechanical lithotripsy was applied in two patients with biliary strictures. Minor complications were noted in three patients, including transient hemobilia in one patient. For a selected group of patients with difficult CBD stones, laser lithotripsy using a double-lumen basket appears to be an effective and safe method. However, continuous development of basket protocols to increase the success rate of lithotripsy is needed.

Further characterization and chemical purity assessment of the human erythrocyte glucose transporter preparation.

Chemical and functional purity of the human erythrocyte glucose transporter preparation obtained by DEAE column chromatography after octyl glucoside solubilization was assessed. The cytochalasin B binding capacity of the preparation indicates that the preparation is 60-85% functional glucose transporter. Gel filtration chromatography on TSK 250 column separates this preparation into at least three major peptide fractions, namely, P0, P1 and P2, with apparent Mr of approx. 80 000, 43 000 and 17 000, respectively. When the preparation is photolabelled with [3H]cytochalasin B prior to the separation only P0 and P1 are labelled. Exposure of the preparation to octyl glucoside or to ultraviolet light irradiation results in an increase in P0 in a time-dependent manner with a concomitant and proportional reduction in P1, without affecting P2 appreciably. For individual preparations, relative abundance of P0 and P1 vary widely in a reciprocal fashion, while that of P2 is practically fixed at approx. 10% of the total protein. The specific activity of cytochalasin B binding of each preparation correlates linearly with the relative abundance of P1 of the preparation, which gives a calculated specific binding activity of 22 nmol/mg protein for this fraction. These results indicate that P1 and P0 are native and denatured transporter, respectively, while P2 is contaminating protein impurities. These results demonstrate that the glucose transporter preparation contains approx. 10% of nontransporter protein impurities, with a varying amount (up to 30%) of denatured transporter, and that the transporter free of the chemical impurities and the denatured transporter can be obtained by a gel filtration chromatography of this preparation.

Fibrovascular polyp of the esophagus in infant.

A five month female was referred complaining of intermittent vomiting with protrusion of a sausage-like mass through the oral cavity. Esophageal endoscopy and esophagogram revealed a mass in the upper esophagus, which was diagnosed as a fibrovascular polyp. Under general anesthesia, the mass was grasped through the oral cavity with a forcep and ligated and excised at the base, where a stump arose from the posterior wall of the cervical esophagus. The pathology was confirmed as a fibrovascular polyp, which is a rare benign esophageal lesion occurring mostly in adult males, and has not been reported in infancy.

Structural basis of human erythrocyte glucose transporter function in reconstituted vesicles.

The transmembrane orientation of the human erythrocyte glucose transporter was assessed based on polarized Fourier transform infrared and ultraviolet circular dichroism spectroscopic data obtained from oriented multilamellar films of the reconstituted transporter vesicles. Infrared spectra revealed that there are distinct vibrations for alpha-helical structure while the vibrational frequencies specific to beta-structure are characteristically absent. Analysis of linear dichroism of the infrared spectra further indicated that these alpha-helices in the transporter are preferentially oriented perpendicular to the lipid bilayer plane forming an effective tilt of less than 38 degrees from the membrane normal. Such a preferential orientation was further supported by ultraviolet circular dichroism spectra which reveal that the 208 nm Moffit band found in the detergent-solubilized preparation is absent in the film preparation. Linear dichroism data further indicated that D-glucose, a typical substrate, further reduces this effective tilt angle slightly.

Structural basis of human erythrocyte glucose transporter function in reconstituted system. Hydrogen exchange.

Hydrogen exchange kinetic behavior of human erythrocyte glucose transporter protein in vesicles was studied in the absence and in the presence of D-glucose or a well known inhibitor, cytochalasin B. This is to detect a proposed channel of water penetrating into the protein through which the sugar molecule passes and to monitor any conformational changes induced by the substrate or inhibitor. Analyses of the kinetic data revealed several classes of hydrogens which exchange with readily distinguishable rates. Of 660 hydrogens detected per transporter, approximately 30% exchanged with rates generally characterized as those of free amide hydrogens indicating they are interfaced to solvent water. Since the transporter is known to be embedded deep in the hydrophobic area of the membrane with minimum exposure to the outside of the membrane lipid bilayer, a significant portion of these free amide hydrogens must be at the purported channel rather than outside of the membrane. D-Glucose and cytochalasin B affected the exchange kinetics of these presumably channel-associated free amide hydrogens rather differently. D-Glucose reduced the apparent rate constants, but not the total number. Cytochalasin B on the other hand reduced the total number to one-half without significantly changing the apparent rate constants. The remaining 70% of the labeled hydrogens exchanged with much slower rates which vary 10-10,000-fold, indicating that they are internally structured peptide amide and side chain hydrogens. Both D-glucose and cytochalasin B further reduced the rates of these hydrogens, indicating a global stabilization of the protein structure.

Structural basis of human erythrocyte glucose transporter function in proteoliposome vesicles: circular dichroism measurements.

The secondary structural compositions of the human erythrocyte glucose transporter in proteoliposome vesicles were assessed on the basis of circular dichroism (CD) spectra measured in the absence and in the presence of D-glucose or an inhibitor, cytochalasin B. We designed and used a scattered-light-collecting device, which corrects CD spectra for optical artifacts originating from light scattering. Relative contents of eight types of secondary structure were estimated by using basis spectra generated by the eigenvector method based on CD spectra of 15 proteins of known structure. Results indicate that the glucose transporter is composed of approximately 82% alpha-helices, 10% beta-turns, and 8% other random structure, with no beta-strands. In the presence of an excess of D-glucose, the alpha-helical content is reduced by more than 10% and there is a significant increase in the random structure content. Cytochalasin B does not appear to affect the secondary structural composition of the transporter to any significant degree.

Inducible RGS2 is a cross-talk regulator for parathyroid hormone signaling in rat osteoblast-like UMR106 cells.

Parathyroid hormone (PTH) activates dual signal transduction systems via Galphas and Galphaq proteins. We now report a novel mechanism by which "cross-talk" may occur between the Galphas and Galphaq signaling pathways. RGS2 (Regulator of G protein Signaling 2) mRNA was rapidly and transiently increased only by PTH analogs (PTH1-84, 1-34, 1-31, and PTHrP) that activated the Galphas-mediated cAMP/PKA signaling pathway, whereas activation of the Galphaq-mediated Ca(2+)/PKC signaling pathway by PTH3-34 had no effect on RGS2 expression. Treatment of UMR106 cells with nonPTH activators of the cAMP/PKA signaling pathway such as cholera toxin, forskolin, 8-Br-cAMP, and dibutyryl-cAMP also significantly elevated RGS2 mRNA levels, while activator of the Galphaq pathway PMA did not. Pretreatment using the Galphas signaling pathway inhibitors SQ22536 and H89 significantly blocked PTH-induced RGS2 expression, but the Galphaq signaling pathway inhibitor bisindolylmaleimide I had no effect. Therefore, RGS2 expression is governed solely by the Galphas signaling pathway. Additionally, we demonstrate for the first time that RGS2 binds to both Galphas and Galphaq subunits in their transition state (GDP/AlF(-4)-bound) forms, suggesting that RGS2 has the potential to act as a bridge between the cAMP/PKA and Ca(2+)/PKC pathways, and that it may act as a cross-talk regulator for these two PTH signaling pathways.