Prevention of ventriculoperitoneal shunt complications after intraperitoneal urological surgeries.

PURPOSE: To evaluate perioperative management for the prevention of postoperative shunt infection and malfunction after intraperitoneal urological surgery in patients with myelodysplasia and a ventriculoperitoneal shunt. METHODS: From 2005 to 2015, 20 consecutive patients with myelodysplasia and a ventriculoperitoneal shunt who underwent intraperitoneal urological surgeries were managed with the same perioperative regimen. Intraperitoneal surgeries involved opening gastrointestinal tracts, including bladder augmentation by enterocystoplasty, creating continent catheterizable channels and Malone antegrade continent enema. We compared results with those from seven previous reports regarding postoperative shunt complications, surgical histories of previous shunt revisions, management of bacteriuria before surgery preoperative bowel preparation, antibiotic regimens, and duration of indwelling drain. RESULTS: Of 20 patients, 18 received prior shunt revisions, and 14 had positive urine culture before surgery that was managed with oral antibiotics. Thirteen patients underwent bladder augmentation with ileum, and one underwent augmentation with sigmoid colon. Nineteen patients underwent Malone antegrade continent enema using the appendix. All parenteral antibiotics were stopped on postoperative day 2.5. Mean duration of indwelling peritoneal drain was 2.7days. Mean follow-up period was 59.8months. Neither postoperative shunt infections nor intraperitoneal shunt malfunctions were recognized during follow-up period. CONCLUSIONS: This is the first study to evaluate postoperative ventriculoperitoneal shunt complications in patients with myelodysplasia who underwent intraperitoneal urological surgeries with a specific perioperative regimen. Shunt complications are greatly reduced by rigorous perioperative management, including preoperative control of bacteriuria, appropriate administration of prophylactic antibiotics, and early removal of intraperitoneal drains. LEVELS OF EVIDENCE: The type of study: Case series with no comparison group, IV.

Retroperitoneoscopic assisted single-site pyeloplasty using EZ access in children: Comparison with open dismembered pyeloplasty.

PURPOSE: The aim of this study was to compare the results of the retroperitoneoscopic assisted pyeloplasty (RASP) using EZ access (silicone rubber cap) with open dismembered pyeloplasty (ODP) in children. METHODS: A retrospective review was performed of patients treated for ureteropelvic junction (UPJ) obstruction with either RASP or ODP from 2010 to 2015. For patients with RASP, two 5-mm trocars were placed in the EZ access. The UPJ was dissected retroperitoneoscopically and dismembered pyeloplasty was performed extracorporeally. Patient demographics and operative outcomes were compared between the groups. RESULTS: A total of 50 children were included, with 25 RASP and 25 ODP. Mean patient age was 49months in the RASP group and 53months in the ODP group. Perioperative outcomes, including operative time (185 vs 188min) and postoperative hospital stay (2.0 vs 2.2days), were similar between the two groups. Mean skin scar length (17 vs 34mm) was significantly smaller in the RASP group. The postoperative success rate (96% vs 100%) was not significantly different between the groups. CONCLUSIONS: The RASP represents a safe and effective single-site procedure in children. This procedure significantly reduces the skin scar length and has equivalent surgical outcomes to ODP. THE TYPE OF STUDY: Retrospective comparative study. LEVELS OF EVIDENCE: III.

Identification of peptides in wheat germ hydrolysate that demonstrate calmodulin-dependent protein kinase II inhibitory activity.

Hydrolysis of wheat germ by proteases resulted in bioactive peptides that demonstrated an inhibitory effect against the vasoconstrictive Ca(2+)-calmodulin (CaM)-dependent protein kinase II (CaMK II). The hydrolysate by thermolysin (1.0wt%, 5h) showed a particularly potent CaMK II inhibition. As a result of mixed mode high-performance liquid chromatography of thermolysin hydrolysate with pH elution gradient ranging between 4.8 and 8.9, the fraction eluted at pH 8.9 was the most potent CaMK II inhibitor. From this fraction, Trp-Val and Trp-Ile were identified as CaMK II inhibitors. In Sprague-Dawley rats, an enhanced aortic CaMK II activity by 1µM phenylephrine was significantly (p<0.05) suppressed by 15-min incubation with 300µM Trp-Val or Trp-Ile. On the basis of Ca(2+)-chelating fluorescence and CaMK II activity assays, it was concluded that Trp-Val and Trp-Ile competed with Ca(2+)-CaM complex to bind to CaMK II with Ki values of 5.4 and 3.6µM, respectively.

Vasorelaxant Effect of 5'-Methylthioadenosine Obtained from Candida utilis Yeast Extract through the Suppression of Intracellular Ca(2+) Concentration in Isolated Rat Aorta.

Our study is the first to demonstrate the vasorelaxant effect of Candida utilis yeast extract on rat aorta (EC50 of 7.2 ± 3.2 mg/mL). Among five identified compounds, 5'-methylthioadenosine (MTA) exhibited comparable vasorelaxant effect (EC50 of 190 ± 40 µM) with adenosine, a known vasodilator, on 1 µM phenylephrine (PE)-contracted Sprague-Dawley rat aortic rings. MTA induced vasorelaxation in an endothelium-independent manner and independent of the adenosine receptors. MTA reduced a CaCl2-induced vasocontraction stimulated by 1 µM PE, whereas the effect was abolished in a 60 mM KCl-induced vasocontraction. This indicates that MTA was not involved in the suppression of extracellular Ca(2+) influx. MTA significantly (P < 0.01) attenuated the PE-induced activation of calmodulin-dependent kinase II (CaMK II) in aortic rings and inhibited the phosphorylation of L-type Ca(2+) channel (VDCC). In conclusion, the underlying mechanism(s) of MTA-induced vasorelaxation involves the inhibition of Ca(2+)/CaMK II/VDCC phosphorylation pathway, resulting in the suppression of intracellular Ca(2+) concentration in aortic rings.

Prepubertal testicular tumors: a single-center experience of 44years.

PURPOSE: To present the clinical and histological features of prepubertal testicular tumors (PTTs), the long-term experience of a single institution was reviewed. MATERIALS AND METHODS: A total of 62 prepubertal children who were treated for testicular tumors at Kanagawa Children's Medical Center from 1971 to 2014 were retrospectively reviewed. Histopathological findings, age at operation, clinical stage, and outcomes were analyzed. Clinical findings between the two eras, 1971-1990 and 1991-2014, were also compared. RESULT: The median age at operation was 17months. Pathology revealed 29 teratomas (47%), 26 yolk sac tumors (42%), 5 epidermoid cysts (8%), 1 Sertoli cell tumor (1.5%), and 1 benign cyst (1.5%). Teratoma was the most common tumor in this series, and children with immature teratomas were operated at a significantly younger age than those with mature teratomas. Yolk sac tumor was the second most common. The clinical stages of yolk sac tumors were stage I in 23 (89%) and stage II in 3 (11%). Clinical findings were not significantly different between the early and late eras. CONCLUSIONS: To the best of our knowledge, this is the largest single-center study of PTTs in Japan. The most common PTT in this study was teratoma, followed by yolk sac tumor. There was no significant difference in the histological distribution of PTTs between the two eras. Compared with the current data of single-center series in North America, the incidence of yolk sac tumor was markedly higher in the present study. This discrepancy is possibly explained by racial differences.

Visualized absorption of anti-atherosclerotic dipeptide, Trp-His, in Sprague-Dawley rats by LC-MS and MALDI-MS imaging analyses.

SCOPE: The basic dipeptide, Trp-His, was found to show an in vivo anti-atherosclerotic effect when orally administered to apo E-deficient mice. In addition, this dipeptide causes vasorelaxation in contracted rat aorta via suppression of intracellular Ca(2+) signaling cascades. In this study, we attempted to determine whether Trp-His can be absorbed after single oral administration in Sprague-Dawley (SD) rats. METHODS AND RESULTS: Trp-His and His-Trp (10 or 50 mg/kg) was orally administered to 8-week-old male SD rats. Both peptides in plasma were assayed by LC-MS/MS in combination with 2,4,6-trinitrobenzene sulfonate derivatization technique. In vitro transport experiments using Caco-2 cell monolayers were performed to evaluate the apparent permeability (Papp ). A phytic acid-aided MALDI-MS imaging (MSI) was conducted to visualize the distribution of dipeptides in the rat intestinal membrane. Trp-His was absorbed intact into SD rat blood, showing a maximal level at 1 h after administration at 10 mg/kg dose (Cmax , 28.7 ± 8.9 pmol/mL-plasma; area under the curve, 71.3 ± 18.7 pmol·h/mL-plasma). In contrast, His-Trp was surprisingly not detected, although the Papp was compatible to that of Trp-His. MSI analysis provided crucial evidence that Trp-His was visualized in the overall intestinal membrane. The Trp-His peptide was not visualized in the presence of Gly-Sar, which is a model peptide that is transported via the intestinal proton-coupled peptide transporter 1 (PepT1) transporter. The His-Trp molecular ion was not observed at the intestinal membrane. The MSI analysis illustrated that there is no absorption of His-Trp due to its unexpected hydrolysis by brush border proteases. CONCLUSION: To the best of our knowledge, this is the first study demonstrating that the vasoactive Trp-His is preferably transported across the rat intestinal membrane by PepT1 and is absorbed intact into the circulation. However, no absorption of His-Trp, a reverse sequence of absorbable Trp-His, is observed owing to hydrolysis by intestinal proteases. This suggests that the bioavailability of peptides may be determined in part by their protease resistance in the intestinal membrane.

Inhibition of calcium-calmodulin complex formation by vasorelaxant basic dipeptides demonstrated by in vitro and in silico analyses.

BACKGROUND: Tryptophan-histidine (Trp-His) was found to suppress the activity of the Ca²âº/calmodulin (CaM)-dependent protein kinases II (CaMKII), which requires the Ca²âº-CaM complex for an initial activation. In this study, we attempted to clarify whether Trp-His inhibits Ca²âº-CaM complex formation, a CaMKII activator. METHODS: The ability of Trp-His and other peptides to inhibit Ca²âº-CaM complex formation was investigated by a Ca²âº-encapsulation fluorescence assay. The peptide-CaM interactions were illustrated by molecular dynamic simulation. RESULTS: We showed that Trp-His inhibited Ca²âº-CaM complex formation with a 1:1 binding stoichiometry of the peptide to CaM, considering that Trp-His reduced Hill coefficient of Ca²âº-CaM binding from 2.81 to 1.92. His-Trp also showed inhibitory activity, whereas Trp+His, 3-methyl His-Trp, and Phe-His did not show significant inhibitory activity, suggesting that the inhibitory activity was due to a peptide skeleton (irrespective of the sequence), a basic amino acid, a His residue, the N hydrogen atom of its imidazole ring, and Trp residue. In silico studies suggested the possibility that Trp-His and His-Trp interacted with the Ca²âº-binding site of CaM by forming hydrogen bonds with key Ca²âº-binding residues of CaM, with a binding free energy of -49.1 and -68.0 kJ/mol, respectively. CONCLUSIONS: This is the first study demonstrating that the vasoactive dipeptide Trp-His possesses inhibitory activity against Ca²âº-CaM complex formation, which may elucidate how Trp-His inhibited CaMKII in a previous study. GENERAL SIGNIFICANCE: The results provide a basic idea that could lead to the development of small peptides binding with high affinity to CaM and inhibiting Ca²âº-CaM complex formation in the future.