Distribution and frequencies of CDH23 mutations in Japanese patients with non-syndromic hearing loss

Mutations in the CDH23 gene are known to be responsible for both Usher syndrome type ID (USH1D) and non-syndromic hearing loss (DFNB12), and the molecular confirmation of the CDH23 gene has become important in the diagnosis of these conditions. The present study was performed to find whether the CDH23 mutations are also responsible for non-syndromic hearing loss in patients in the Japanese population. A total of 51 sequence variants were found in 64 Japanese probands with non-syndromic sensorineural hearing impairment from autosomal recessive families. Among them, at least four missense mutations in six patients from five families were confirmed to be responsible for deafness by segregation study. All mutations detected were missense mutations, corroborating the previous reports regarding DFNB12. The present data confirmed that CDH23 mutations are frequently found and significantly responsible in Japanese. Interestingly, the CDH23 mutation spectrum in Japanese is very different from that found in Caucasians. This Japanese spectrum may be representative of those in Eastern Asian populations and its elucidation is expected to facilitate the molecular diagnosis of DFNB12 and USH1D.     

Thirteen week toxicity study of dietary l‐tryptophan in rats with a recovery period of 5 weeks

Although l ‐tryptophan is nutritionally important and widely used in medical applications, toxicity data for its oral administration are limited. The purpose of this study was to evaluate the potential toxicity of an experimental diet containing added l ‐tryptophan at doses of 0 (basal diet), 1.25%, 2.5% and 5.0% when administered to Sprague–Dawley rats for 13 weeks. There were no toxicological changes in clinical signs, ophthalmology, urinalysis, hematology, necropsy, organ weight and histopathology between control rats and those fed additional l ‐tryptophan. Body weight gain and food consumption significantly decreased throughout the administration period in males in the 2.5% group and in both sexes in the 5.0% group. At the end of the dosing period, decreases in water intake in males in the 5.0% group and in serum glucose in females in the 5.0% group were observed. The changes described above were considered toxicologically significant; however, they were not observed after a 5 week recovery period, suggesting reversibility. Consequently, the no‐observed‐adverse‐effect level of l ‐tryptophan in the present study was 1.25% for males and 2.5% for females (mean intake of l ‐tryptophan: 779 mg kg^–1 body weight day^–1 [males] and 1765 mg kg^–1 body weight day^–1 [females]). As the basal diet used in this study contained 0.27% of proteinaceous l ‐tryptophan, the no‐observed‐adverse‐effect level of overall l ‐tryptophan was 1.52% for males and 2.77% for females (mean intake of overall l ‐tryptophan: 948 mg kg^–1 body weight day^–1 (males) and 1956 mg kg^–1 body weight day^–1 (females)). We conclude that l ‐tryptophan has a low toxicity profile in terms of human use.     

Dose-related effects of direct hemoperfusion using a cytokine adsorbent column for the treatment of experimental endotoxemia

Objective To clarify the dose-related effects of direct hemoperfusion using a cytokine adsorbent column (CTR) on the mortality and inflammatory responses to endotoxin-induced shock in rats. Design Prospective and randomized study. Setting University research laboratory. Subjects Male Wistar rats. Interventions Forty-eight rats were injected intravenously with Escherichia coli endotoxin (15 mg/kg over 2 min), and then were randomly allocated to one of the following four groups (n = 12 per group): control group, treated without CTR for 120 min; quarter-dose treatment group, treated with CTR 0.25 ml for 120 min; half-dose treatment group, treated with CTR 0.50 ml; and full-dose treatment group, treated with CTR 1.0 ml. Measurements and results Hemodynamics and arterial blood gases were recorded, and mortality and plasma cytokine concentrations were calculated for the 8-h observation period. The mortality rates 8 h after endotoxin injection were 92%, 58%, 42% and 17% for the control column, quarter-dose, half-dose, and full-dose CTR groups, respectively. The increases in plasma cytokine concentrations were smaller in the half-dose and full-dose CTR treatment groups than in the endotoxemic group. Conclusions The present study showed that CTR treatment dose-dependently decreased the mortality rate and inhibited inflammatory responses in vivo. There was no supported funding in this study.     

A very narrow preexisting isthmus in a case with typical atrial flutter

A 61-year-old woman with typical atrial flutter underwent an electrophysiologic study and radiofrequency catheter ablation. The electroanatomic mapping revealed two contiguous lines of distinct double potentials (DPs) extending anteriorly/posteriorly from the coronary sinus ostium to the inferior vena cava (IVC) border. A large part of the anterior line of the DPs was close and parallel to the tricuspid annulus (TA). An initial discrete radiofrequency application at the very narrow preexisting isthmus between the TA and anterior line of the DPs completed the IVC-TA isthmus conduction block.     

Predictors of postoperative early recurrence of extrahepatic bile duct cancer

Resected bile duct cancers often relapse during postoperative follow-up. The aim of this study was to detect predictors of early recurrence in patients with extrahepatic bile duct cancer. Consecutive cases (n = 162) of extrahepatic bile duct cancer in which R0 or R1 resection was achieved in Kobe University Hospital between 2000 and 2016 were divided into three groups [early recurrence (ER), within 6 months of surgery, late recurrence (LR), and no recurrence (NR)] and their clinicopathological features were compared. Twenty-two patients (14%) developed ER and 69 (43%) developed LR after surgery. The rates of lymph node metastasis and residual cancer status were similar in all three groups. Liver metastasis was more common in the ER group than in the LR group (59% vs. 32%, p = 0.02). ER had a significantly worse prognosis than LR and NR (7% vs. 44% vs. 85% at 1 year, p < 0.01, respectively). Multivariate analysis showed that age > 75 years, serum CA19-9 > 1008 U/ml and perineural invasion were independent predictors of early recurrence. High serum CA19-9 values (> 1008 U/ml) were an independent predictor of early recurrence. Neoadjuvant therapy and aggressive adjuvant therapy may be beneficial for patients who show highly elevated CA19-9 values before surgery.     

Free anterolateral thigh flap with vascularized lateral femoral cutaneous nerve for the treatment of neuroma‐in‐continuity and recurrent carpal tunnel syndrome after carpal tunnel release

Treatment of recurrent carpal tunnel syndrome (CTS) is challenging, especially in a case with recurrent CTS and a neuroma formation. Resection of the neuroma causing the syndrome, reconstruction of the nerve gap of the median nerve, and covering up the reconstructed median nerve with well‐vascularized soft tissue for prevention of CTS re‐recurrence are the essential procedures. We report a case of recurrent CTS with severe pain due to a neuroma‐in‐continuity successfully treated using a free anterolateral thigh (ALT) flap with a vascularized lateral femoral cutaneous nerve (LFCN). A 2 cm neuroma existed in the median nerve and was resected. The nerve gap was repaired using a vascularized LFCN included in the ALT flap. The ALT flap was transferred to the wrist to cover the median nerve. The severe pain disappeared completely and the sensory and motor impairment of the median nerve improved 5 months after the free flap surgery, as the Tinel's sign moved distally away from the wrist and disappeared. The result of the Semmes‐Weinstein test improved from 5.08 to 4.31 and she was able to flex and extend the right wrist and fingers without pain. CTS did not recur 15 months after the surgery. A free ALT flap with vascularized LFCN allows nerve reconstruction for the median nerve gap created after neuroma resection and coverage of the median nerve with well‐vascularized soft tissue to prevent adhesion and CTS recurrence. © 2013 Wiley Periodicals, Inc. Microsurgery 34:145–148, 2014.     

Use of non‐enhanced angiography to assist the second toetip flap transfer for reconstruction of the fingertip defect

Toetip flap transfer is a useful reconstructive method for fingertip defect, but elevation of a toetip flap is technically demanding because of difficulty to dissect a pedicle vein of the flap. Recently, nonenhanced angiography (NEA) has been reported to be useful for preoperative visualization of the digital vessels without contrast enhancement or invasiveness. We report a case in which preoperative NEA visualized a vein suitable for a venous pedicle of a second toetip flap and facilitated successful toetip flap transfer for reconstruction of a fingertip defect. A 27‐year‐old male suffered from the right middle fingertip crush amputation in Tamai zone 1. The fingertip was reconstructed using a second toetip flap with preoperative NEA guidance. A pedicle vein was easily found and dissected exactly where NEA visualized. Nine months after the toetip flap transfer, the reconstructed right middle finger was functionally and aesthetically pleasing, and the toe nail at the donor site was preserved without any morbidity. NEA may help a surgeon to find drainage veins for a toetip flap, which leads to easier and more secure toetip flap transfer. © 2014 Wiley Periodicals, Inc. Microsurgery 34:481–483, 2014.     

Redo cardiac surgery for active prosthetic valve endocarditis associated with hereditary hemorrhagic telangiectasia: report of a case

Hereditary hemorrhagic telangiectasia (HHT) is caused by an autosomal dominant gene and characterized by multiple arteriovenous malformations in several organs, leading to bleeding or shunting. These patients often suffer severe infections and heart failure, which should be managed in the perioperative period, when open heart surgery is indicated. We report a case of successful aortic root replacement for active prosthetic valve endocarditis and ventricular septal perforation in a patient with HHT, who had severe heart failure.